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NH DEPARTMENT OF THE INTERIOR

MONOGRAPHS

OF THE

UNITED STATES GEOLOGICAL SURVEY

V7 © le UsMen ei

Part 1.—-TEXT

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(7 Sn ees

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WASHINGTON
GOVERNMENT PRINTING OFFICE
1912

by UNITED STATES GEOLOGICAL SURVEY

GEORGE OTIS SMITH, Director

CAMBRIAN BRACHIOPODA

BY

CHARLES D. WALCOTT

WASHINGTON
GOVERNMENT PRINTING OFFICE

1912

CONTENTS.

GENERAL SUMMARY OF THE MONOGRAPH.

Geographic distribution, by continents, geologic provinces, and States or countries...........................-
Stratigraphic distribution by States or countries, with typical or general sections, correlating localities and fossils.
Habitat, alphabetic list of genera and subgenera, giving data on.._._...........--.----2.--.------------------
Localities, by number, with lists of fossils and reference to position in stratigraphic tables
Terminology adopted for the monograph
ID @inHAMETOINS Cie GMOS Ze cottages era Ea es veer ICN nt ey Oe esaY BUN DNs oO RU ree eR tan ee Ba
Miners lees in GhuTaleleahUnesiys o-5- fer Uc) iss ste SS Scere ee seme eee at remem opclie pe ae EAD ethic ok BUN ee oe A
Evolution, schematic diagram of, for all genera and subgenera
Classi callonmialevanceamalarsiste ses: 25 sch 6x55 eee ery oe ee ee ays Ee atc ee ee) = Ey AS Seed it
Description of genera and species

Si MOM MN CHCLETEM COS Mefea se rr- ase cislalcl 2 en)-!o.2/s 22 Sw 2s 2 = INS a See Sei Meee Bee Seen cee emu ess
List, by genera, subgenera, species, and varieties, of references in synonymy, with present reference of each.
MEO LOR CRG Ata eee ere tn nee, SSIS AT Ls wy OL SS Ne fe AMEN gosta My a St 2) Segue len clu ce aires eel era a ome ERE SNS!
Generaliccorraphicamndstraticraphi ci distribution: ssss-- 94426 eeseeee seen ee eee ners eee seen ee eee eee
Mistriloutiongowgspecles seers oe 2s sess Moss = le see ac veces eeteiee Sele ee Sa cio ne eae Res eee a eee
General geographic and stratigraphic distribution of the Cambrian and Ordovician Brachiopoda. -
Summary Or Chicdlanionn Iyevcleuoy oe. sgeneso genes csesscsscscesse sabodcsnesasonedddsaaneccsaSce
Samay Or Onclonm@eya Iii VCloWoyOC, ec naonacsscope so Sas ease sages qocsng ses sosnocesscesseacesoasc-
General summary of Cambrian and Ordovician Brachiopoda...........---.-------------------------
Metaillediceosraphicrdistrilo ution: 4224-4. be) cle tos essere siete Sysgye ele etetsiete oer ste eos eles rnc oe aecs ciate
Camibniame brachiopod aerrsats'= 2s ;ce.c= = sinc slssis ceed e Syne ae em se UTS Set te ee eae Ne ee ee se ee eee
North American species.......--.---- RA SER AE Sees OCB n.L SUB OOS eo eae BOE aa t/a oa aan

AUTO PCAMESPEELES ey ers. Yall te oe. ed uu Sitls 8 dates BS cateyoycie ab ae eyetare lef iste aye PR) Cleo Se Esa

PAST oUt CAS COLES RC Nard de. . Syato.5 15s ayase BE eee epee SNe sie Ste EN ee oe eo RT Ak Ont oe er
SouthpAmm enlcam species: .54.o0 226 32/26 2 seks Sikes Soke See ae ee ee ee wine ee oe eae eer

PATHS LTA AMUSE GLESMa 9. Mae = y2iae va esse maa= See seid eae eee eae weer = ee eee eae enya
OrdovicianpBrachiopodase yess eee ee eee eee eee eee eee eee BR tS NOR old Heo Caen
NortnpAmericanispeGles-.o-e<sjauetlas seine saice ese mC ee ae ei Sea nies ete ea eye Vo ere eee
HMROPCAMESPECCIESS =f ayes sean ste hes sees Nestlss Bee e-em ee See eee see ase sie seo eases
Detailed stratigraphic distribution of Cambrian and Ordovician Brachiopoda.-............-.-.------------
INDO 536 dsacacsse aoe oon poe BOE Ene ener se teers. airlon descend at sok ase keunese Anan aes

IB Gharsreatheh ee a eee a eee a ae RGA Serpe tk en WR Ss Ae ea a A
British Columbia: Mount Bosworthe 222252922422 4-525- 42522 s eee eeee = BES pada HORA orem eetae
(CRINIGTHING) so cons GCOS COG aE Aa ERE ED eee a SOA Aas SUS ee noo SAA aor oh eee eee aoe
Cape Breton and New Brunswick....----.---.-.-.------.--------!- Bros oR aR ERe aes Oise TO SSN OBESE
(ClollonarGlo ies ieeace aon eae ene eee RPE SNe 6 SOA ere Rett iy es Eerie nol area ne

6 CONTENTS.

Geologic data—Continued.

Detailed stratigraphic distribution of Cambrian and Ordovician Brachiopoda—Continued. Page.
Michigan......... Se ce Rene oem era iae Seer eph ec cd ipocavauuhunden sso sac qaceeqcesspecsoezece 136
Minnesota. .--.---- be (ud Oe eae de cea e ee Sesee ba eeceo srs sens asec os ncoeesdesasceconsaceresesedansecos 136
Missoumnie 2.502 eee eee eee ee ee eee eee See ee eee 6) AS al Ree Re Daren eo 137
Wikoyaqienoey PuaKel WAV OMIT. sone ea oner enc eso see scesgocsseseso2ss82ess0e5 HIS SAT Cae UP Se 137
AN een ID ATT US fo 1 Eyes es lays
UN eesvren cl ears Ee Bea oe ete 139
INGunlbetha sgl «sco oeecaatenoceausescas -4osonse cose sees sheet acs asssestedasesscsescoesessaoce 140
Newfoundland: Manuels Brook, Conception Bay-....--- we aot ac vey te Re SCI aN gh 140
INC ap Gord eee een a aeons Sake aeRO dom ESoeS ee sebSsddusaaesdesacesadocssosoasees 14]
Norway-.---:-2-. BOR Ee Bon ee bre nnn osonr ape san tasaaeoss semen oe dsb cseouseeoe see otodcb ones 141
INN ANI SCCLHE po seanesasacadsee bso sooccposeacosdso- secs un sonac ssenoscosed sour ossoceeasondessousazes 141
Ovkdeloorenae Aniqielels MiouINiiOSs- 2 ss cacssces ses see sec ada serge sesso seco be sssoeesocseecessncuners 141
Onmmaloeeeadacaubanorecasoosbrosasccseudooccos be cweesodbonesseose Caro sbcsocordoddooeseoodasceos 143
Teyana Gute) dace ae scsoenosssnoar sobs ecucw coc cusscbdos cee ec sesabenzsqeasesseasssacsbessanodess 143
Quebec, Ontario,’and Labrador 30a. (sey. sae sean des | Uae weet eee re fee eee 143
Iie ee eee Renate Aaaee GEeao sae oO aomE tole coadalds beso oman eerboseseocmasorSddoce 143
Sood ENC ene E een OEMS Sado Ine Gees oon cer obo Whee OdREsecach Gado chmoesmduhorssascuseécssds 144
your) a eco te eal Vy Te 144
Sweden, Denmark, Finland, and Norway-.-..-..------------------- Seeley eal ere een kes BEN 144
Mernarsssee., Gyeorne),, auavol IN MOp NE 32522 nono es saeeosaococ es sa codoate ne sesso scenscesocesssereosccse 147
U if -> ¢: 1: He eee cae aan ora aS taen een wean orn « Sauce S ce eEEEan Rn ecummamaaccocabogresoncosac 148
ital laclesmurtihyHorices @2c ben © ont yey eee eee eee 148
[Whisins Telos.) IAS, Whirl Cowmaliiy. .-sass-- sence sscse sess ee sc oceocs see ase soscosassesgussosussoccs 153
Auten anos Pe ameA Eames Haen ona bBSERemcesnes senae Cogdacdsoauacteaue ds odowasesersasa 159
Varese euricllp Tearsy7l enn Ce eee eee eee eee 159
MMI oscuaaamsbosdo-s S5ase esoesepcuss odeacssaEerasoAdosneresosds oe scccneresenscasscsss5ce5s0q5e% 159
Wisconsin, Michigan, Minnesota, and lowa.......-.-.-.------------------+---+-++-++-++-+------------ 159
Wiyominge scene osc cere aes Ses ae oreo acta tae REPRE Rabon g Se nal BR Bi 28 iw Ss 159

1S HE Meee aes Oe eee Ae bor Beoemanoaadceaca se aopaeGesaesess cert comedas GacdoauswESosadecwsesesescdode 159
List of genera and subgenera, alphabetically arranged, giving number of species occurring in the dif-

ferent types of sediment .........-.----------------- +--+ +--+ 22-22-2222 0ce reste rst tee teste eres 160

BOM bhalS}oCee ae PR Rea eee nao ame ao ene eerode aes Hamer sannace oSosnodocotsdussaseuuGsdogeseesescadcesooss 160
(Doreeiiities 132777, Wi. Si. Nenniormnel! WittsemIn. 0352 25-5 oe sone e coe seas oon eas secassacsedcsseessancns 161
Localities 300-3962, arbitrarily numbered .-..---.----.----.-_------------=2----1--5----2- = --- =. 229
Localities 01-075, Carnegie Institution of Washington Expedition to Chima.......-.---------------- 286

Zoological discussion...-..-..-- ee a Ee ee eRe ol oO R ao ee oeeeaa a aoa oan de ueEE aaoacCSe eos 291

Terminology....--------+-+------- 2202s eee eee eee ee ee eee eee 291
Generallstatements-ae see sao eee ee ae rete eae ee eee orate eee tee eat 291
Wefinthi Onsys: casas ee aes ee eee eee eer ie ee eee eee ne eatsn Sate soe chr Sct 292

The brachiopod shell. ........--.-.----------- +--+ +--+ 2222252222222 222222 etree eee 296
Structures asec s-tees seeker eisnes Been pbs essere setae Sapans sedate seenesacostetbasonseeasasdbec 296

General statement...-......-.--.-----2--+-+---!--------------- ab opoeuseesadee CASE SHEE 296
Microscopic structure. ....-.-.-.------------+--+-+-+-+ 2-2-2222 22ers 297
Surfaceromamentatlony2 esse seer eee eee See eee ea Seee eee ne eee eee eee eee 300
(Gemenall Nsitettieran erties eee eee eee 300
IMME Ee a eee soo e stab u ot sa sucasasebanoonssbasuauedessosecuecasolgsnoosessocesesoolyo 301
Neotremmatas ote Sepia ese eS ap eee Se ee ota ete ee et eS 302
Protremartaise es eo ee a ee ree Sees ees eee tare alle setae seat ee 302
iimbenloc)cimp lia Om see eee sees eee eer Pas Goer aan eH! 20 ra Bal eee eters 303
Cardinal area.....-.-..- Rane Shee Ree ese E eo Le Ps oe re tie Onn nar sce namazastane) | ws)
IAVEReTIVa tar: refer, fae rahe cape sicher er palate teva eee eeen ne donb eke Hod aouubevodesqeascseenseacsbsabceedoue 303
Neotremata: 2.2) Bee ote Se aa oe SS Oe Eye ae ee eet 304
IBHO MENA E cooooke cna geacooéaanscoonceSooosescesce ge etat ape Neto ate aye as ewe ore eer eee Peet tay 305
Delthyrium and deltidium.............-...------- +--+ +--+ -+2 2222222222 eee 305
lin jnehth gna e ee ene Oe MAREE saree jaa abarcaornoncopopooucescosdsadeqaHetecbSSsS4sescSbr KS 306
lek wilbuebibbesasBenAn ne soba npobeogEssonocenabacedacsagoeenncussasecoocoeescconceacoese PoE aeed 306
@ardimall process’ = =o) ee fies =a ele ae ale eee eee eee eit OSE EEOC SGE 306
Articulating processes... 22.2 a= -- eee ace seit 2 le ote ae teeta eet eet eae ele eee teeter 307
Spondyliumye 4.22. Ses san soe ace Sane om teiee eles eee eee ie eee ie oe telat eiee 307
Ghulam oh so Sleek oe Se eo oe Se Ee oe eee eerie 309
1G Hust eee REM ae ee sl ane Oe eee ME My Somes UA ANd socom aa sock ebomG Saba sseoacésce 309
SC) SiE Hos peerbo ened satoe ane pas pa Scere mene en aaseroanuoseca taco sosmasheasasosesoscaus so SdedsoeRs 310

CONTENTS. 7

Zoological discussion—Continued.
The brachiopod shell—Continued. Page.
Wersouillaie imaigin cline ae Bee eee oe oS GUAM ING SAE ets 6 SS Cre at ELSE Bonet ee MRP as Sor ee es ee 311
JNUITIGHION Dae Hels BSB Mar Oates = 4c SHeSH ee os cae Se Sa4 Aaa Oe bea a oa Gs Sonn aan aes Are SEciaene ee 311
[Neo tmenn ala saa: = acu! 2 a) zo emmy sess eee eee te ee es A THUS Ec. oC NS 311
PSTOURETINENDA eT yest i (ct SnIe eee EERE A tk Ue) A SR a Erle sa AUBE Ve SOY con 5 2/2 | Ere ta aS 311
INI ROR Aer aoen mentee Sas a edocer ekuE Osos Shear See Dea NEN Sons eee eee Sahn yee ee 312
ENUERGNTEGT IY 5 ee NEE TET ERNE sees US tant oO Se) rE a 312
INIGOURETARIE i aaos Sa eens tS cen eee ee eso aa ae ie aan oid wo eA mmm ot, 5 reer A 312
IPIROUIRSIAID 3 SS MD Sol ae ewe SAS" GSE toean c AA e See Ge Ree OER Asie Bet an oN 313
edie) egimicramdvapenuuUre ss... vaste jes SAS salem eeprom erarets ee eA ey Ta Tt. = UR Abreegs ge eR Do 314
PANDY TIN ULL eatsrats ko Seats !S, 2.2 aia 2 svete epee IE to ate eM Ln a Ser ay rep IR RU) yes WUE A TU eh el eee Ns 8 314
INGOURGINGIE SSS seee eee iG aan ost euO eas Senate tind tate aoe mere ene Cet naa Se aca meer 314
JPLRGARRETTAEC) sc es eet ee RR Se Sa aI Gy ate Es FO GES PRN eye peers US aes DS Shae 315
Oldracercharachersess 2 Dak yc Nei Nis eee ye ea Pee NRC MIP EPL (Ls oa Oh Aelita te Pas Reataiegtsg eh ya 315
IDIstmlo MOI Thin Chin SHEE neared cose cde so uaEMaesasdeccsscae cour eaE ease oHoneedeEesEeLe mabe. 315
Bvralaiion OF tile Carmnlordenn levee MOOG 55 Gace ss bebse soo sensuESse obs usabounsessesseatdusdsesueasses 316
Sclema tlexdacra miei hoes, 2). Sie i Ten oO Muy een Sneed ae Napa Aat et een egee gt ae Weaae. Sa Spy neh mae bh 316
JNTOTION saa OS USSD ee eee ee Ie eee aes ee ae ae ato GCE See Car sen se a are 318
INIGOURS EME) < SSS Serer ces res eRe eM PEN ote eR teu tes os rt eat eat ape rth eae le a Pe aS EA 319
LEXRO CERO OY se se Bic Ne I ae an tt PR ree are a aaron a ea Se 319
(CHE SSTHT CERT O IL oo 5 Sis Ae eRe ete ee gS a Rca SIA Ci tt es Sem Ve ev Syl
OGLE ANI SOE eS SoA REE EIS ae en omen aie SUIS Hen Eee arin apt Ree Nene HES 322
Se MEATIAN EUS CC LACE 213). orn s alae tate SAVeTe 2 caste operas = ee RNR Coa Ie ee erm Sn RE na Re 322
Wena hyp IRL See ees Ae Re Soa ers he.4e Aapecee a aee sek oaer nay eo EeSAC Se oabeee 322
IRejennlhy IEA er vTap Geeieapetn |Get set tele Yee ens rie’ beleive Met Nia cee har N 322
Superiarmilliva@ bola cea sos sis acs cctsters Ohm ere Ae eRe em ieee eyo Sa ao ce ores peer yee ae 322
PliammilyaCurbi Cid cee Misi cei we eats eee os IS SS SS eT ae aaa ee a = vee 329
ingumnilhy Q)noliiele as vay eee ema nae y= Eee aca ae NaN se WAS ke Gemend Uaet en ane anoauase 322
St familys bolineey 52... ey sey tn ete UE ee Cee ENE crete aie toe eg geen BBE
Sioa GAOL) eh iil ele. Heese Sse nee ee Doe GAN OWtn aL aC acuGseHOoSeee eMac ase nese r 323
Sulbtamanly: INGO DOMM ses. 52 3528 Aaa ae Cone else oe ale Ss ore ayn age Saat Eee eae or 323
Suloacalky leone ate Hes Meee, toe SOAP ae Nucci saan eG sso aanae See soo nae SaeaeG 323
SuperrannilbyaKeurtoreina, cea: 98%. sae 2 Meese ete eee Ae ancl Seis = Smee aSeE Eo eee 323
igeirountl hyp. 1cont nop etna ke eee emanates a emee TO eth seat es iin aie AI) ooo ia ea a ce etal ein aoa cal 323
ammibyas churchertimid cee.) en seer vento see sae ee ete eee eee eae eee 323
OrderaNico trem atamtee oases aes se oe ee Sot Se ae oe eee Ree oe See ees Serer sft aU ame ee 323
SUpertamillyes iphone tre tacea 28 coe mens aja aie ees yee a ates Ser eyar el Pe yey Mere oe EES TP par seage pe 324
TRarsanlky O)o ile ene eaariets a sce Sepa tare megs Sts he Seno LACS oh Jat a be Ne ee ewe Eu 324
peal hia Sipllo ORO Wee See aaaces aaa Sodeats dooeenodtadeae ee adese Goene ne acanecaouaoan 324
SUpeLtamaillye ACrOUMe LACCVE a2 <= pyar sral= <i ts a ete se Varco Sele are eae Pree eS ole eee ory 324
Hamil eAtcrotre tid eis, seo apse His St 2 sn atoee ee Seige eee eo Te Oe oer See 324
SWlotammulliyaAlero the limes. 5 csc. z,Seve eee eave ore ae eer Pe Se ee ee ety ee eens eee 324
SublamilycAcrotretimee:..22'.\ Mase Se) soceaia se eeises See Ce ee ee eae eee ee 324
SupertannlysMiseimacea sa... 22500 seas 5 tases sider ele te escolar nie seer eee ieee: See Bere 325
Tobieanl yy? ID iG he yee eee ge SAREE NEADS au Gad 5 coat ede Oe nae yee 325
Sinjecimiamn hy Cienvuevecy poseeesseacmdnsosdusesaaapesecers sodee aden ccedaacuadseusebenoosaEdnene 325
HammtlysCraniidee: <.c- 222. gi sacs osc send heise ss eben gee Sees se ae See ce see ee e a ae eae 325
Orderpknoinemia tas ses 23 SL a ele SE esd Sz tao BE te eee PR Ta se ore VE ee 325
Siipentamallye Onthec eas sees ee sogadreooacessecucsacscocgssscs0sssccosgsssorserce 325
Haniibyapillhmosellad ces 351515 -/ob 2 ye 4 ise eee eee eee ROE Seen ee eee ae 325
Sulpkuallhy INS lines 6 eemaaaneeas seeeocesocossGuosdeoedcndspetuadsesadesesossonaacs 325
Subfamily Billingsellinz......-. aisidaacee HA Sa toner enn epee hee aera aes ee rae 325
Subfamily Boorth ine .282 8-3. /2 Nano -5 eee nes eee a eens eee Mee eee eee Cerne 326
SupertamillysS trop homens ceare: ac see te eee lee eee eer ae ee eee ey eee eee 326
Ipayooull by Saroja iNeMNG ED Os seneo cose pene coast Hea deosobe ena sco sbsaebs dasanmsanasasedadssaane 326
Subfamily zRafinesq wim: ece ss see ase eeee aes emerson eae ne eee eee ae 326
Swipeminnillhyy |eieMN ECP noc cee coz ocon esc econesecrecdsorscans ouesassosceusosenesesezeeeseec 326
Hamby, Syntrop htt de sic. 2.1.2 Sofas 2, ate sere ole aa eee en es ie ne area ere a ctl eee 326
Weseripbionsolsceneraand (SPeCles 2) - 22a) 5 2c .<-.-ta)ast Vetere sree rae een Veter oe hot ten een Ay ste eon SR 327
IRusinalllby Welledlitc eat selves > case pepenDEC eRe nos Doe Cupros he qeeEosseosoccosEeenay Rr hed Sone eaters 327
Wiley alizal, SolnimiGhit eee Se suns so. uceoaene tae aaa obe Sader sono ns saad bbane sna ooo seb osSSa ane saan essen 329

a The list of species on pp. 98-109 gives the names of all the species in the order in which they appear in the monograph and also not only the
page but the illustration reference and other information. It should therefore be of more value to the student than a mere list of speciesin these
contents, and such a list has accordingly been omitted. The pages upon which the genera and subgenera are described are not shown in the list on
pp. 98-109; therefore these are shown here.

8 CONTENTS.

Description of genera and species—Continued. Page.
Miecromitra Meek. se 50. cic. je hile sheen Skat Ae age iey ss clea oe ee Sake it] ES ee 332
(Paterina)’ Beecher as. ): ¢ 2.3 -2.cnscdeds <2e eng e): eae eee eer oi: 2 =< RCP EEE EOS a enter 343
(Golmicleila) Welleoiiti.. 2 nccseseessecn eo. Ee SaaS ee NO ING: «1 pCR oe caged a 359
Volborthia, von Mollerisa e325 c toe 2 Goa ys eee ere ca tore Rate 1 a 365
PWelmersenia: Pander sey coho sacle d oe Lai Helge gers cee le AS = (2 2S ee I 367
Curticia Walcott. sce ee septs See oy re ee eee NE, See oR soe (oN ci hy AG a Ry eRe 369
Obolus:Hichwaldls ut 32225 oad Ss bis Shes Ui Seine par epi pele aes (ol 2 5 AO ea 370
(Broggeria), Waleottsi2: 22202 = oi ese sta cee Seem bee A) 2 isc SAS ee ES ees aaa eee .- 424
(Paleeobolus) Matthew se to0 222 sx ws eter pete eeveyee creer eo eo a ee 426
(Fordinia): Walcott. 23226 S25 sh LUA a pre oecrae oer ee e 2S n= ope ore Tea eae 428
(ingulobolus) Matthew: 2.2) 6es 2 ace te eos Ott pepsi TA ane. ahs ao Uy eon el at 430
(Mickwitzella)Walcotte.% 5 .c25.20 ee ha) ee eee rl ae 380 CEPR Ss te Oana RE 434
(Acritis): Volborthe . p55 se. Sos She 3 ee ANA eA 2h, 2 Sle sig es ie A a re 437
(Schraidtia) sWolboorthy 20 aici Se sett ee eae eS ce 52 re 1 tt a2 ae 441
(Westoniia): Waalleottat i3c@ seh occet ros ee a iret peti a ERS 880 os oS Pea er 450
Ting ulella | Salter see eee ae eee eae re EE et Seas IS terete wl i eee 468
(Geptembolon)!Mickewatz. facsscci she tts hs caine se baciete Sk 25 Sh 5 8 Sin a cals yearn 541
(Lingulepis): Halse cals se aie eee ete teen oye Sree sie oie is = ie age cue A lean es See ees eee 544
Melsadellia, Walcott: ewes to yee AN ese St ea Coty sk aie SIN, ie Bes LS Se a ete a eee 560
DUI eeh ous a sKo)k0 Ree eee ANA Unie se nah ae nw On ME a eM ane 5 amen anos Se eclbaae Gal 561
Neobolus (Waag ent a Seee Sone ci sey a), Jct male ea al Nal) a aN ar ese apc hess en ps Po 564
Bicia Walcott: sc cipte ace ost Aci Se nee Nh SEN Sad ererele ert Rated arena ces Me et ey a 568
Dicellomins Mallee Geeks sees Lae ties le hs oe eR ES hos ostwiew.e Meese sere cee at See eee ee Sanelntes 571
‘Kutoroina Billings: itis aes oes. se ee ON 2 a Seta) ca epee ee pe eS ey as Ss re ee eae 579
Schuchertina; Walcotts< cies Soe eS oases s Slaps oe erento aa ates ee Oe 585
Obolella; Billimesij2- 25 ose hse oon teens sess = Hee ba) See eee Sees oo Se oe eee Eee REECE 586
(Glyptias) Walcott. suc fe 2 = aceeenasee hoa Looe 2 eee b oee MelSe ee a ciate or ee eee ee eee ee 599
Botsfordia/Maibth ewe nk eke aoe ov eeteee ee Sees Sete geek oe Mapes alee se ope aere Lick s,opereyae apes Ba 601
Schizopholis Waagen........-..-.-- ets eRe ee Oana ene iG sa ome eG Sasa Sa tawen cs DES A ee 608
@uehbecia Walcott sss hse Sets cece cue Sa isis clematis ee a sf E LS ee Ie eee ST a azeoee: 609
Yorkia Waleotiti eset coasso- mae otencecnes bec ced see asceioe selene Sent DEE ee Sao ee eer ee eee eee 611
DearbormiayWaleottssissst heck cease dos ys ce tae ate bee o Beeins ata cen ok Sh Se OSE Re ee See ee eres 614
Mrematobolus Matthew: . 242.50 fasece eae ie oe vacltlne is Sadao so =o REE See ES eee eee ee eee 615
Schizambon' Walcott-2 cosas the Sk ARGS ce Syn NE Oct Ie Oey SR a 622
SiphonotretaideyVermeuil O25 2 3s- jasc ise eas ee AES ope fee a tore ele oS ee eee ee 624
Keysorlingia. Pander’ s scshe dhe. touastosie sate one Beige ee eine t Sad aes be Seiten Tae ee Pereira erp 628
Acrothele itm arssone se 9523 aa Oe eee a ee ae ee SE et ae 630
(Redlichella) Walcott.:3..0% ...g2s2Oc sk fe si cnis Stacia cia We wis cision Carsiceie ise mesa SSS el ee Sees Mereeegeies 662
DisciniolepissWaaaem: = 54: Si -185 serie. pee oS reese SPS ae en Rett 2s tara ar 664
Linnarssonella ‘Walecotta: sca ese ne ote ee 8 oem ss cre oha le ears eat ye a e e 665
‘Acrotreta, Kantorgaics fo otcteheteee 5 mceyh aio Ses SSSI ah cens SRA NSS re a 671
Acrothyra: Matthew: 2 2chise2 3 ees =e 2 Sea SS a cesta AE te ty Ne ee ee teas Ae ee 715
Discinopsis Matthew sh tee aie egh Say ake Oe Sir teretey ie BAR een chee ec cas et seat rena 720
Orbiculoidead! Orbigwry. — SoM aoe ayers he ee eae STE SE are aS Stes et aa 722
Philhedra. Koken. ic 8 52/2605 oan dik ope aah oe pave tacos AE la See ee ape ele yeatey als es ene nee age nese ea 724
INistsia: Wallcotts. .c% 38 23.) towel Ns Bab Pee ee iSO WNL TNS oh Mien teen age Ecce eget 725
(Jamesellla) Walcott yssse. eek ahs Set es Ne ee reste ere ope tate iv ME Ue eres GA Hara on Ue 731
Protorthis) Halland: Clarkes asc 32 Ugg eb ccc ce cele eet yee sche aaa rato Aa Ee ea 738
(uopenia)) Walleotte seo as) 1Cae caesar eae eee e sien ts yas Oye Shakey HS es Me Ree gate ge era --. 744
Wimamellas Walcott) yesh 52 S208 ef oa tere ee peers Mesa ete eyeyel ayes ete eg al Sl 745
Bilkinesella: Halland ‘Clarkese 20 oj ee gs 2 ee ee eine ule Saran Ser eine ene ease FEE eee eee eeeeeeaae 749
Orusia; Walcotts «so-so 25. eleva 2s siemcaa sc well etelege eae ee aie ae aie ee Se 765
Opusia Walcott secs. 2) a2 SUA s Se epee Se ee rere Tee ear SR ig 769
Wyma Wallcotite sss sesaqein scien Tec RES res Se oe Re AS Ie SN IE oO 771
HMoorthis Walcott. 2 ceke echt Ae MS ee Sota ASI I re Ape RR ge SS Se 772
Rinkelnburgia Walcott e's 20s cance sela- 5 oe boson Sow kk ae ee ee one alae eine See eee eee 793
Hostrophomena *Walcotts sass ce tos Getler see cscs See SIS Ae Stee SUNS ey i oe et ne ae ye ora 795
SwantoniaWalcobts ese a 25 Se cee alee ee coe ae ee gen ey a 796
Syntrophia: Ealltand: Clarkes). d) 205 \eeie cise neces ee Ee eee ee ears ane 798
iene llasWialeott xc eae acs seers yes See eyes ee = eee ice Sik a ee ete nee ee ae 805

ClarkelllasWwralleotitea sone © e455 pes Ree os Bes Loh dee eh Ca Ea a 2 a 809

ee

ILLUSTRATIONS.

Page

HESTHANTU SEO TAV Renee tesiateta (ee = Saree Sets 2 ca aI SNE SSE ayer ete ee te get raat a' 2 cick n) bye ise eo eiete ee Cee OEE Part II
rcurmpleeSillimeselia plies tell ae s/2 oy pvey pears /e eee net tana eye miUeie jose ele) DCM a ae 299
9, Delbenee eye oconeim eesee ctaes.adeae ao Cnadac sie Soc SS nea teres See EE Crear ts tae Boas 299
Sm keuvoreinaycineullata . . </oko e as meae mere ece Sete yt errr Menem crete ye 22 2 iste om cemereewies ma mentees 299
248 0) FONT Sp a779 OLN TIAA Se at ete Pape ate Ts toee te ruse eee 8 NO isy crete ele teem cle yet! Ne 299
Owbiiimesellacoloradoensist. saa toe eee aes te aioe Sam > sos 2 sles Nees seen race eee ele 299
GsaNtsuisialfestin avtay (26/51) jo ie Semen carer VI Relea fay ee Steril I Saha SEI ee nie ates else eee 299
HesWoontinisyrem ml Chia sd, < kiss ska ne aa ears ete eee cep Qc Ney cd Scape SUN Pel eG ae 299
Seekartoroinartcinen ataesss=seees eee ase Tifa ANP RUE or spolies Soscwents, AL aaa Jide Peery ie es ah 299
Sen Dalmanellammaull tiseetay- 4125-1 nclera se ar aee pe eta ee ein ae re = ae Shae ele ere ce Meee Ee 299
ORM alm anellapanyad se acl! cto ee ak eet A RSC eee eS arco Se eee aye eee yee 299
HELE Syaniro pli, la teralise 2c )-ts21. 2s semen iacs <i eoeae is see set sen eet eR seo NSN RE SE NUME ane 299
2s electorthissplieatellay. -: 22 Sas: Sani eee eae asa Scie ed ans erse Wee eae Seance antes 299
3 sku eels abmormise jlo Ps 2. 22 Ree clay ee ts mess ee ele eve de Meee au tes so al ue 299
EO bolellaverassam ls epee se scp eo oe a Re St Pare > Sterne pey Bey eee places yc a/R ERO Lae Mh rae 299
Sea Obolusyapollamigee seers! o/c) he Weert epee ee ete ee ores ete lays alae cle aida yey ayers el eee see ea 299
1G, Breage TOMA: cosctosessbesneooohesksoesddsocons sped oops onccaus oss seonosesusdauescsuauens 314
17. Diagram illustrating known distribution of families in Cambrian strata...........-....--..-------- 316
18. Schematic diagram of evolution of Cambrian Brachiopoda.................--..---+--+------------- 317
HOMME UStel ayn ay Ob sacw see tales saracta aie iota ee Ie TsTee ee a ee Pe pees eee Se Cee eer Eee 328
20: Micromitra haydeni_.2.-.--......-...-2.- SES SESH 5 ge SHE aE ae Ie Sasa re eee Cees end 5 BSCle mae aie 338
21. Micromitra scotica......--------: PS op ies ee ean dis Soest ee eM nya GN maT We SL LPauace 340
22. Micromitra sculptilis endlichi...............--.- asics Ree Ue ieee == pePs ole “ts celeste See eyes 342
23. Micromitra zenobia.......--.-. Be ETN Ete ie a I Ie EN tI OS RP eee ee SEN A 342
244 Micromitra) (Paterna) labrad onicarwtahensishesssere ss -s2 == see eee eee aoe eee see eee ees 350
25. Micromitra (Paterina) major-..........-.----.- ogadsodceesocsosoasagscascospesoneosesass socsuane 351
26. Micromitra (Paterina) stuarti...........-..-- Biot Souder amasin Sted Roce Heme ne AN GLB a, ane 355
eet cromutray (i abentina)) SU eri alee ener Pree tte erste ee ers foe eee ee ra ese eee ee 355
2 See vicronat tray ((Rasterims)) yur dl Ose ete ier etre ey Ser ar Arete etn ye rere Sree eee pe 356
20 re Ma cromutra, (aterm. a))> Wap ua ecere st ast \-y- pe recta er ele pie oases teeter lo ee eee sree ener ese 357
30 Micromitra)(Paterina))williargn sy.) scl e secee cee ten ee ere ee nO Noctis ea eet 0 yelp ag Pee 358
SieeMicromitray (phi della) MoWISe. 22 ie cat-r ae mee ae ee eons etsy SE 2 eres eee ee ae re 359
32, Wixom (hola cenit eee ean do tooe a Gas nosaye sues ose sepodee=dearatoanescoscouonee 362
So MO ORbtnIa; TECURV AS - jas si faysleiaise Be chaps Stee se SA Spe Sola tay sem eye ty hs SRN tate Ua Nae a Sp 366
34. Interiors of valves of Obolus apollinis quenstedti and Lingula anatina..............-............ 374
SO MOHOMUS MOAT US ess sc My as ase ee alee pies eeeiey ayaa sarees Nays cence ce Bla, aac ta el eaters ee eee Mi 390
Or Oboluspmemibpranmace us: <7 yj 2s 21= is pene are ret ee rates oes heey Aa ea ne Os BO ET 403
eof OO OLS PATRI = tryst sve 2 ese sts ett ee edt ee ree Se TOE Pee Pee rnmree C 408
SSan@O bolus eran tha 24 eee cpa) 2 ope Ms ye eene eel ares a el ee ot Presb gel aa) el cepa a 416
BO MOO lus! WOrthend ce Deysrsta ie nse o Sees srr PE ee ee Se cay gs eat ee aN 421
A0Es@bolus: (Westonia)) dartowls-caccaset see teens ote acre ee ae ee ee oe ere oe heces Sewn eee ae 455
Alen@ bolus (Westomia) i wasatehensig ys 2/30 ite oven tn haces AC tars, peer nes est gine ae Peete ea RE c te voll = ere Np A467
AO salbimgarlellal;clarweres cea ah saa Scare ete CSI es ey SEPM een Ses co nae RIE Eom Sa A eae. rt oie ie 486
AS eapI OP ULCER ISSO bc 82 ees. Sook perches ape te Veet res ete pe ese eevee ee AR eo ina Ones Byte Le 510
AAealbim oul CMa truparylise |: «hc ,c ks eee Dever a eibgensiers ere erecta ads Ne uray tbe Mum NIU <A eves aly ON Mya ae 537
A MMM MLE MAN ZOU! - ate08 oe a nits cistcincE cere ea cree el err A a ee Sal ame es OP ah ae CAT TL MM 541
AG oun ella (rine nile pis) a cumunataise QU er sear se ees a es ee ee yee ree eee une 551
ATeeNeob olustwartha' 5. s.icie)= onic 2 eee ite gue Hee enema) eae oR ES gabaecascasescaseaeoe 567
Ag seDicellomus pectenoid es: -& = =e ee pe a trae ane eee een ee Peeps a ee 575
A). Drreailkay aos) ons gacosastessoseeer ane gocsencoes8s5 conn deHos shar onesssnodakescnseauscdendecous 576
BO; AiO aE enn LR Ol meriadoraaen cate ab adnse 5 Soe sem AAs euReUNCe aE US ee oo Rut Ander came oe ee 581
olemObolellla tart] amit cary 22 7 Aime ha lear | Ae cee ae ee eee oe ess ee cera ees re YN Vee eT 590
2 MO DOLE AT OT OOM ep a5 eyes a hia ln ara eee ee ene Tes Eee cee et eM prey Sp 596

10

Figure 53.
54,
55.
56.
57.
58.
59.
60.
61.
62.
63.
64.
65.
66.
67.
68.
69.
70.
ae
72.
73.
74.
75.
76.

ILLUSTRATIONS.
Page
Qbolella vermilionensis. 2.5. <0:25 28 sae se ss os rn ee a oe eoietys CP ee ee ee 598
Nerothelelartemiseeesee sss eee eee cielo a Ra ZN SIN satay ee rvs Ae 634
Acrothele collemiic ac 25-22 i aa sees Sane inee haa os mae ER De ee eee eee Je ic NS Somes eee 641
Acrotreta carinata sss oi 2 ges ae Sess ssae eee eee ect ES crete tee ee eee eee 680
Acrotreta circ wlarisit ses Eee, seiecs Seater sieal tee = 2) eee eRe 680
Acrotreta kutoreaiesoie oda 02 De SP eS See ee a epee ae ac eae ie cs epee ae 692
Acrothyra Minors. o45 12s ee a 5s es ae hts ae eo eee sscs2e ooo ee 717
Nisusia nara: Js. see nt ae seein cae eae he: Beato eee eno = eee Se ey aero ees Sono “7a
Nisusia .(Jamesella) owas 25254 Soe 2 speere eyes oat Se Se SEIS Shee ee OEE Ee ne ee ee 734
Nisusiay(Jiamesella) spencer: : sascsi SoCs Ee Ae he siete as ls) el ee aan Mato vn ees 737
Wimanellapim y oemsis: ssi cero 5.2 aiie eo a es ae ee eee he eo a epee or ee eee 747
Wimanella simplemay cs fs2 eh 52 saa = sc eS ere te erage Fates 2 he PN oe PAS ye ae 748
Billingsellabivia Se 22 Ses sees ete teisead Pe ee ees ae Be eben aie 5 enue es VES ECS crepe Pe 750
Billingsella coloradoensis ss 2 See eke ester ene oe ap clele. seu E reeves eS opee a aes ea 751
Billingsella) mariony. (2. ca.c8 ees cece ee ee eyes SOLS 1 alli CU ects le NR Ry AS 758
Wey mina (wart ia ihe ea ie ets ok Se meee ces RSIS aye lpg eee ect yO ea eg RD 771.
Hoorthisimew berry v2 is. Sot See ee Neca ire oe 2). Gi ee )eie See Sie regu are Been rere eee 783
Hoorthis,thy omen oro. bee yas es ee ey ba Site law 2) Secin dos pene oe ee eRe ae at 789
Moorthis:zemo sis era. Gee Se Rae Se Be Sl A Ss 2s ra ec Sense ee eee ensue 792
Syntrophia. cambria stile. os Sap sok ek AONE ol ste a ae) SNS ya ieee, pat ea ea Re 800
Syntrophia:campbellisnssos Stee sue ye ne eee eS ae Ce ee eee 801
Synirophia tuum ssc he Pelee ele sles AER crepe Nera |e ce nse etary Sete epee 805
Eluenellailesleyan 32. joe here Meese ek gate Nene Soe See cee ee eer ee Ses 807

Huenellavermomtamans23 2 stis acc ces Sosa ease See cts rae in Oe Se Ee eee 809

CAMBRIAN BRACHIOPODA.

By Cuartes D. Waucort.

INTRODUCTION.
PREPARATION AND SCOPE.

It was not until after the preparation of the preliminary memoir on the fauna of the Lower
Cambrian or Olenellus zone* that I began to think seriously of undertaking the systematic
study of the Cambrian faunas of the world. The second extended contribution was the memoir
on the fossil Medusz,° after which studies were continued on the Brachiopoda. Administra-
tive duties have greatly interfered with the prosecution of the work, but by taking advantage
of all opportunities, both in the field and office, some progress has been made from year to year.
The work is not so complete as it might be in its discussion of genera and species, details of
evolution, and the relations of the Cambrian brachiopod fauna to Ordovician and later faunas.
My main purpose has been to make the results of the investigation of value to the student of
Cambrian faunas and to the stratigraphic geologist. ‘

This monograph includes the description of 44 genera, 15 subgenera, 477 species, and 59
varieties of Cambrian Brachiopoda, and of 3 genera, 1 subgenus, 42 species, and 1 variety of
Ordovician Brachiopoda. Of the Cambrian forms, 10 genera, 2 subgenera, 21 species, and 1
variety persist into the Ordovician. (See pp. 98-113 for complete tables giving distribution.)

In this paper the Brachiopoda are treated in three ways—historically, geologically,
and zoologically. Historically the treatment comprises (1) a bibliography and (2) a table of
synonymic reference, giving a completely cross-referenced list of described species with the
present generic and specific reference of each. Geologically the distribution of the Brachi-
opoda is considered under the following headings: (1) General geographic and stratigraphic
distribution; (2) detailed geographic distribution; (3) detailed stratigraphic distribution; (4)
habitat; and (5) fossil localities. Zoologically the discussion covers (1) the physical characters
of the Brachiopoda; (2) their distribution; (3) their evolution; and (4) their classification.
Lastly come the detailed descriptions of genera and species and the illustrative plates.

ACKNOWLEDGMENTS.

In the course of the investigations of the Cambrian brachiopods during the past ten years
I have received assistance in various forms and degrees from many individuals in all sections
of the world where the Cambrian strata and faunas occur. To all I return my most grateful
acknowledgment and sincere thanks. If any who have assisted me are overlooked in these
acknowledgments, I beg leave to assure them that it is not by intention.

Dr. Ferdinand Schmidt, of the Royal Institution of St. Petersburg, sent many specimens
and valuable notes on the range of the species in the Upper Cambrian and Lower Ordovician
beds of the Baltic provinces of Russia.

Dr. A. Mickwitz, of Reval, Esthonia, Russia, sent material from the Obolus beds of Russia.

a Walcott, C. D., Fauna of the Lower Camprian or Olencllus zone: Tenth Ann. Rept. U.S. Geol. Survey, pt. 1 1890, pp. 509-763.
b Walcott, C. D., Fossil Medusz: Mon. U.S. Geol. Survey, vol. 30, 1898.

11

12 CAMBRIAN BRACHIOPODA.

‘Mr. J. F. Nery Delgado, of the Geological Survey of Portugal, presented photographs of
several of the Lower Cambrian brachiopods described by him from Portugal, also a specimen
of the new form Delgadella lusitanica.

Dr. Charles Barrois, of the University of Lille, France, gave information in relation to the
Cambrian faunas of Span and France.

Dr. Karl A. Grénwall, of the Geological Survey of Denmark, made a collection of Cambrian
fossils for me in Bornholm, among which were fine representatives of the brachiopods described
by him in his memoir on the Paradoxides fauna of Bornholm.

Dr. J. F. Pompeckj, of the University of Hohenheim, Wurttemberg, Germany, was always
ready to give information and assistance. .

Dr. T. H. Holland, director of the Geological Survey of India, generously loaned for study
the collection of brachiopods from the Cambrian formations of the Salt Range, and gave me
the opportunity of studying and illustrating Doctor Waagen’s types.

Prof. Walter Howchin, of the University of Adelaide, South Australia, sent for sais
and illustration all the types of Cambrian fossils described by Messrs. R. ‘Duherdice, | jr., and
Ralph Tate.

As a result of the expedition of the Carnegie Institution of Washington to China under
the direction of Mr. Bailey Willis, assisted by Mr. Eliot Blackwelder, large collections of fossils
were made from many faunal horeens of the Cambrian, and among them the various brachio-
pods described in this volume.

Dr. W. C. Brégger, of the University of Christiania, Norway, very generously loaned the
types described by tana | in ‘Die Silurischen Etagen 2 wim By” also duplicate material of Cam-
brian brachiopods which he had collected at various lloealities | in Norway.

Dr. N. Olof Holst, of the Geological Survey of Sweden, very kindly took charge of the
making of collections of Cambrian fossils for me by Mr. G. Schmalensee, a collector of the
Survey, and also permitted the sending of specimens for study and in exchange.

Dr. Joh. Chr. Moberg, of Lund, Sweden, both loaned and presented material for study.

Through the courtesy of Dr. Carl Wiman, of Upsala, Sweden, I had the opportunity of
studying the Cambrian brachiopods described by him from the North Baltic region. He not
only sent me the specimens, but also answered inquiries in relation to certain facts concerning
them which did not appear in the text of his report.

I am greatly indebted to the Geological Survey of Canada for the loan of many of the types ~
in the collections of the Survey museum. Prof. J. F. Whiteaves and Dr. Henry M. Ami were
especially kind in selecting and forwarding the specimens desired.

Sir William E. Dawson permitted me to look over the collection of the McGill Uni-
versity museum, and later Dr. Frank D. Adams sent specimens of the Cambrian brachiopods
in the collection.

For many years before the sale of his collection, Dr. George F. Matthew, of St. John,
New Brunswick, frequently loaned me his types and study material, and also when I visited
New Brunswick directed me to the most favorable localities for collecting material both in
New Brunswick and Cape Breton. When his collections went to the University of Toronto,
Prof. W. A. Parks sent to me from them the various types that I needed for study and ime.
tration.

Prof. Alexander Agassiz permitted me to study the collections of Cambrian brachiopod
in the Museum of Comparative Zoology, and also to take to Washington and have illustrations
made of a number of specimens, especially those from Bohemia.

Prof. J. M. Clarke, director of the New York State Museum, Albany, N. Y., was most
courteous in lending material and giving information relating to it.

Mr. W. A. Finkelnburg, of Winona, Minn., sent material from his collection, and also made
collections from the ‘‘St. Croix sandstone” at several localities in Minnesota which enabled
me to add very materially to the description of the Cambrian brachiopods of Minnesota.

Prof. Alpheus Hyatt, of the Boston Museum of Natural History, lent material he collected
on the coast of Labrador, and he was always ready to discuss problems connected with the life
history and evolution of the Brachiopoda.

BIBLIOGRAPHY. 13

To no one am I more indebted than to Prof. Charles Schuchert, of Yale University, whose
suggestions and comments, made in response to questions submitted to him, and also as the
result of examining the plates and the preliminary draft of the zoological discussion, have
been most helpful.

From year to year material for study was brought in by various members of the United
States Geological Survey as opportunity offered, and large collections were made in the Cor-
dilleran area of the United States by Mr. S. Ward Loper, of the Wesleyan University museum.
I collected personally from various parts of the United States and Canada, England, and Wales,
being assisted in the Cordilleran area by Mr. F. B. Weeks and Mr. Lancaster D. Burling.

During the course of the preparation of this monograph I have received from time to time
effective assistance from members of the United States Geological Survey, especially those
directly acting as my assistants. When studying the Acrotretide Dr. George H. Girty selected
material for illustration and also made preliminary notes on some of the species. Miss Elvira
Wood separated and classified the brachiopods collected in 1905-6, directed the preparation
of drawings, and, in 1906, revised the proof of the plates, which were printed at that time.

Mr. Lancaster D. Burling, of the United States National Museum, revised, verified, and
tabulated the synonymy and localities and assisted in many ways in the final make-up of the
text of the volume from 1907 to 1912.

At my request Mr. E. O. Ulrich, of the United States Geological Survey, carefully read the
zoological discussion and made notes that led me to make several modifications, especially in
relation to the protrematous genera. I have included in the text his observations on the
spondylium.

To Mr. R. S. Bassler, of the United States National Museum, I am indebted for a number
of thin sections of the’ shells of Cambrian brachiopods and a few Ordovician orthoids and for
notes on the sections.

The drawings have been prepared mainly by Miss Frances Wieser, of the United States
Geological Survey. The plates are the evidence of her faithful work.

HISTORICAL DATA.
BIBLIOGRAPHY.

The following bibhography includes the works referred to in this monograph,’ arranged
alphabetically by authors and chronologically under each author:
Ami, H. M.:

1887. The Ottawa Naturalist, vol. 1, No. 9, 1887 (Dec.), pp. 121-126: Notes on, and the precise geological horizon

of, Siphonotreta scotica Davidson.
BarRranpb, J. (see also DE VERNEUIL and BARRANDE):

1848. Naturwissenschaftliche Abhandlungen, gesammelt und durch Subscription herausgegeben von Wilhelm
Haidinger, Bd. 2, Abth. 1, No. 5, 1848, pp. 153-256: Ueber die Brachiopoden der silurischen Schichten
von Bohmen. 4°. Wien.

1868a. Il: Faune silurienne des environs de Hof, en Baviére, 1868 (Dec.), pp. 31-110 (published with I: Réap-
parition du genre Arethusina Barrande.) 8°. Prague.

1868b. Neues Jahrbuch ftir Mineralogie, Geologie, und Palontologie for 1868, pp. 641-696: Silurische Fauna
aus der Umgebung von Hof in Bayern.

1879a. Systéme silurien du centre de la Bohéme, vol. 5, pt. 1, 1879, pp. 1-226, Pls. I-LXXI. 4°. Prague.

1879b. Systéme silurien du centre de la Bohéme, vol. 5, pt. 1, 1879, Pls. LXXII-CLIII. 4°. Prague.

Barros, C.:

1882. Mémoires de la Société géologique du Nord, tome 2, Mém. 1, 1882: Recherches sur les terrains anciens des

Asturies et de la Galice (Espagne).
Basster, R. S.:

The lists of phyllopods cited under several of the localities on pages 161 to 291 were furnished to me by Mr.

Bassler from a manuscript copy of Ulrich and Bassler’s memoir on the Phyllopoda, which is now in press.
Brecuer, ©. E.:
1891. American Journal of Science, 3d ser., vol. 41, 1891 (April), pp. 348-357: Development of the Brachiopoda.

a £xceptions are: Albers, p. 434; Balsamo-Crivelli, p. 441; Baly, pp. 332 and 334; Clarke, p. 441; Iddings and Weed, p. 417; Marshall, pp.
434 and 441; and Stose, p. 271. i 1

14 CAMBRIAN BRACHIOPODA

Bressy, J. J.:
' 1868. Thesaurus Siluricus: The flora and fauna of the Silurian period, with addenda, 1868. 4°. London.

Biuines, E.:

1856. The Canadian Naturalist and Geologist, Ist ser., vol. 1, 1856 (Feb.), pp. 32-39: Fossils of the Potsdam
sandstone.

1857. Geological Survey of Canada, Report of progress for the years 1853-1856, 1857, pp. 247-345: Report of
paleontologist for 1856.

1859. The Canadian Naturalist and Geologist and Proceedings of the Natural History Society of Montreal, Ist
ser., vol. 4, No. 6, 1859 (Dec.), pp. 426-470: Fossils of the Chazy limestone, with descriptions of new
species.

1861a. The Canadian Naturalist and Geologist, Ist ser., vol. 6, No. 4, 1861 (Aug.), pp. 310-328: On some of the
rocks and fossils occurring near Phillipsburg, Canada East.

1861b. Geological Survey of Canada, Paleozoic fossils, vol. 1, 1861 (Nov.), pp. 1-24.

1861c. Report on the geology of Vermont, vol. 2, 1861, pp. 942-960, appendix: On some new or little known Lower
Silurian fossils from the Potsdam group (Primordial zone). 4°. Claremont, New Hampshire.

1862a. Geological Survey of Canada: Paleozoic fossils, vol. 1, 1862 (Jan.), pp. 25-56.

1862b. The American Journal of Science and Arts, 2d ser., vol. 38, 1862 (May), pp. 100-105: Further observations
on the age of the Red sand-rock formation (Potsdam group) of Canada and Vermont.

1862c. The American Journal of Science and Arts, 2d ser., vol. 33, 1862 (May), pp. 420-421: On the date of the
recently published report of the superintendent of the Geological Survey of Wisconsin, exhibiting the
progress of the work, Jan. 1, 1861.

1862d. Geological Survey of Canada, Paleozoic fossils, vol. 1, 1862 (June), pp. 57-168.

1862e. Report on the economical geology, physical geography, and scenery of Vermont, by A. D. Hager, 1862,
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1863. Fifteenth report of progress, Geological Survey of Canada, from its commencement to 1863, 1863.

1865a. Geological Survey of Canada, Paleozoic fossils, vol. 1, 1865 (Feb.), pp. 169-344.

1865b. Geological Survey of Canada, Paleozoic fossils, vol. 1, 1865 (Oct. ?), pp. 345-426.

1868. Acadian geology, by J. W. Dawson, 2d ed., 1868, p. 643: Description of Hocystites primxvus.

1872a. The Canadian Naturalist and Quarterly Journal of Science, new (2d) ser., vol. 6, No. 2, 1872, pp. 213-222:
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1872b. The Canadian Naturalist and Quarterly Journal of Science, new (2d) ser., vol. 6, No. 4, 1872, pp. 465-480:
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1872c. The American Journal of Science and Arts, 3d ser., vol. 3, 1872 (May), pp. 352-360: On some new species
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1874. Geological Survey of Canada, Paleozoic fossils, vol. 2, pt. 1, 1874 (Aug.).

1876. The American Journal of Science, 3d ser., vol. 9, 1876 (Mar.), pp. 176-178: On the structure of Obolella
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1882. Geological Survey of Newfoundland, Report of progress for 1881, 1882, appendix.

BuacKWwELpER, Exior (see also Wintis and BhackK WELDER):

1907a. Carnegie Institution of Washington, Research in China, vol. 1, 1907 (Apr.), chap. 2, pp. 19-58: Suneinie
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1907b. Carnegie Institution of Washington, Research in China, vol. 1, 1907 (Apr.), chap. 12, pp. 265-279: Stratig-
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BiocHMANN, FR.:

1900. Untersuchungen tiber den Bau der Brachiopoden, pt. 2: Die Anatomie yon Discinisca lamellosa (Broderip)

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1878. Nyt Magazin for Naturvidenskaberne, Bd. 24, Hft. 1, 1878, pp. 18-88: On paradoxidesskifrene ved Krekling.
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1834. Physikalische Abhandlungen der Kéniglichen Akademie der Wissenschaften zu Berlin, 1834.

1841. Archiv fiir Mineralogie, Geognosie, Bergbau, und Hiittenkunde, Bd. 15, Hit. 1, Abh. 1, No. 1, 1841, pp.
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BIBLIOGRAPHY. 15

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Daman, J. A.:
1828. Kongl. Vetenskaps-Academiens Handlingar for 1827; 1828, pp. 88-155: Uppstillning och Beskrifning af
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Davipson, T.:
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pp. 135-242, Pls. VIII-X VII. 4°. London.

16 CAMBRIAN BRACHIOPODA.

Davipson, T.—Continued .
1884. A monograph of the British fossil Brachiopoda, vol. 5, pt. 3, Silurian and Devonian supplements, 1884 (Dec.),
pp. 243-476, Pls. XVIII-XXI. 4°. London.
Davis, J. E.:
1846. The Quarterly Journal of the Geological Society of London, vol. 2, pt. 1, 1846, pp. 70-75: On. the geology of
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Dawson, J. W.:
1888a. The Canadian Record of Science, vol. 3, 1888 (Apr.), pp. 49-59: Preliminary note on new species of sponges
from the Quebec group at Little Metis. :
1888b. Peter Redpath Museum, McGill University, Montreal, Canada: Notes on specimens, Apr., 1888, pp. 49-59:
New species of fossil sponges from Little Metis, Province of Quebec, Canada.
1890. Proceedings and Transactions of the Royal Society of Canada for 1889, Ist ser., vol. 7, sec. 4, No. 3, 1890,
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Deteano, J. F. N.:
1904. Communicagdes de Commissio do Servigo geologico de Portugal, tome 5, fasc. 2, 1904 (Mar.), pp. 307-374:
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Dwieut, W. B.: j
1886. Proceedings of the American Association for the Advancement of Science, 34th meeting, held at Ann Arbor,
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1889. American Journal of Science, 3d ser., vol. 38, 1889 (Aug.), pp. 139-153: Recent explorations in the Wappinger
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_Ercuwap, C. E. von:
1829. Zoologia specialis, quam expositis animalibus tum vivis, tum fossilibus potissimum Rossie in universum,
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1843a. Beitrage zur Kenntniss des russischen Reiches, Bd. 8, No. 1, 1843, pp. 1-138: Neuer Beitrag zur Geognosie
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1907. Bulletin United States Geological Survey No. 315, 1907, pp. 31-35: The Granite-Bimetallic and Cable
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ErHEeRIDGe, R., jr.:
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Forp, 8. W.:
1871. The American Journal of Science and Arts, 3d ser., vol. 2, 1871 (July), pp. 32-34: Notes on the Primordial
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celata.
1881. The American Journal of Science, 3d ser., vol. 21, 1881 (Feb.), pp. 181-134: Remarks on the genus Obolella.

BIBLIOGRAPHY. 17

Forp, 8. W.—Continued.

1886a. The American Journal of Science, 3d ser., vol. 31, 1886 (June), pp. 466-467: Notice of a new genus of Lower
Silurian Brachiopoda.

1886b. The American Journal of Science, 3d ser., vol. 32, 1886 (Oct.), p. 325: Note on the recently proposed genus
Billingsia. i

Frecu, Fritz:

1897. Additional plates (without cover or title-page) received at United States Geological Survey Library in 1897
from the publisher with instructions to insert them in Lethzea geognostica, pt. 1, Letheea paleeozoica,
atlas, 1876. 4°. Stuttgart.

GaGEL, C.:

1890. Beitrage zur Naturkunde Preussens, herausgegeben von der Physikalisch-oekonomisch Gesellschaft zu,
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Proyinzen Ost- und Westpreussen.

Goruam, FrEeDERIC P.:
1905. Bulletin of the Roger Williams Park Museum No. 9, 1905 (May), 6 pp.: The Cambrian deposits of North
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GrRaBau, A. W.:
_ 1900. Occasional Papers Boston Society of Natural History No. 4, Geology of the Boston basin, by W. O. Crosby,
vol. 1, pt. 3, 1900, pp. 601-694: Paleontology of the Cambrian terranes of the Boston ‘postin,
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1907. North American Index Fossils, vol. 1, 1907. 8°. Lancaster, Pennsylvania.

Gray, J. E.:
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1892. Neues Jahrbuch fir Mineralogie, Geologie, und Paleontologie, 1892, Bd. 1, pp. 69-70: Ueber eine cam-
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1896. Verhandlungen der russisch-kaiserlichen mineralogischen Gesellschaft zu St. Petersburg, 2d ser., Bd. 32,

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1847. Natural History of New York, Paleontology, vol. 1, 1847. 4°. Albany, New York.

1851. Report on the geology of the Lake Superior land district, by J. W. Foster and J. D. Whitney, pt. 2, 1851,
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1859. Twelfth Annual Report of the Regents of the University of the State of New York on the condition of the
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1861. Report of the superintendent of the Geological Survey of Wisconsin, exhibiting the progress of the work,
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1863. Sixteenth Annual Report New York State Cabinet of Natural History, 1863, pp. 17-226: Contributions to
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1883. Second Annual Report of the State Geologist of New York for 1882, 1883.

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1894b. Thirteenth Annual Report of the State Geologist of New York for 1893, vol. 2, 1894, Paleontology, pp. 641-
646: Table of classification of the Brachiopoda.

62667°—vo1 51, pr 1—12——_2

18 CAMBRIAN BRACHIOPODA

Hatt, J., and Crarke, J. M.:
1892a.¢ Eleventh Annual Report of the State Geologist of New York for 1891; 1892.
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a This date (1892) is taken from the title-page and is used throughout, but the work is clearly antedated. See p. 615.

BIBLIOGRAPHY. 19

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1879. Sveriges Geologiska Undersékning, Afhandlinger och uppsatser, ser. C, No. 35, 1879: Om Faunan i Kalken
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McCoy, F.:
1846. A synopsis of the Silurian fossils of Ireland, 1846. 4°. Dublin.
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1851b. The Annals and Magazine of Natural History, 2d ser., vol. 8, 1851 (Nov.), pp. 387-409: On some new
Cambro-Silurian fossils.

20 CAMBRIAN BRACHIOPODA.

McCoy, F.—Continued.

1854. A systematic description of the British Paleozoic fossils; with a synopsis of the classification of the British

Paleozoic rocks, by A. Sedgwick, 1854. 4°. Cenasctdles
Marana, L.:

1875. Boletin de la Comision del Mapa Geoldégico de Espama, tome 2 2, 1875, pp. 1-160: Sinopsis de las especies

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Marttey, C. A.:

1902. The Quarterly Journal of the Geological Society of London, vol. 58, pt. 1, 1902 (Feb. 18), pp. 135-147: Cam-

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Matrunw, G. F.:

1883. Proceedings and Transactions of the Royal Society of Canada for 1882, Ist ser., vol. 1, sec. 4, 1883, pp. 87-108
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1886. Proceedings and Transactions of the Royal Society of Canada for 1885, Ist ser., vol. 3, sec. 4, No. 4, 1886,
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1888. The Canadian Record of Science, vol. 3, 1888 (Jan.), pp. 21-29: On a basal series of Cambrian rocks in
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1889. The Canadian Record of Science, vol. 3, 1889 (Jan.), pp. 303-315: On the classification of the Cambrian
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1890. Proceedings and Transactions of the Royal Society of Canada for 1889, Ist ser., vol. 7, sec. 4, No. 12, 1890,
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1891. Proceedings and Transactions of the Royal Society of Canada for 1890, Ist ser., vol. 8, sec. 4, No. 6, 1891,
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1892. Proceedings and Transactions of the Royal Society of Canada for 1891, Ist ser., vol. 9, sec. 4, No. 5, 1892,
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1893a. The Canadian Record of Science, vol. 5, 1893 (Jan.), pp. 276-279: Trematobolus.

1893b. Proceedings and Transactions of the Royal Society of Canada for 1892, Ist ser., vol. 10, sec. 4, No. 7, 1893,
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1894. Proceedings and Transactions of the Royal Society of Canada for 1893, Ist ser., vol. 11, sec. 4, No. 8, 1894, ©
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1895a. Transactions of the New York Academy of Sciences for 1894-5, vol. 14, 1895, pp. 101-153: The Protolenus
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' 1895b. Proceedings and Transactions of the Royal Society of Canada for 1895, 2d ser., vol. 1, sec. 4, No. 13, 1895,
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1895c. Bulletin of the Natural History Society of New Brunswick, vol. 3, No. 13, 1895, pp. 94-95: Report on geology.

1897a. The Geological Magazine, new ser., decade 4, vol. 4, 1897 (Feb.), pp. 68-71: The oldest Stphonotreta.

1897b. Proceedings and Transactions of the Royal Society of Canada for 1897, 2d ser., vol. 3, sec. 4, No. 7, 1897,
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1898a. Proceedings and Transactions of the Royal Society of Canada for 1898, 2d ser., vol. 4, sec. 4, No. 2, 1898,

"pp. 123-150: Studies on Cambrian faunas, No. 2.

1898b. Bulletin of the Natural History Society of New Brunswick, vol. 4, pt. 1, No. 16, 1898, pp. 32-43:
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1899a. Bulletin of the Natural History Society of New Brunswick, vol. 4, pt. 3, No. 18, 1899, pp. 189-197: Prelimi-
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1899b. Bulletin of the Natural History Society of New Brunswick, vol. 4, pt. 3, No. 18, 1899, pp. 198-208: Pre-
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1899c. Proceedings and Transactions of the Royal Society of Canada for 1899, 2d ser., vol. 5, sec. 4, No. 2, 1899,
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1899d. Proceedings and Transactions of the Royal Society of Canada for 1899, 2d ser., vol. 5, sec. 4, No. 3, 1899,
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1899e. Proceedings and Transactions of the Royal Society of Canada for 1899, 2d ser., vol. 5, sec. 4, No. 4, 1899,
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1901la. Bulletin of the Natural History Society of New Brunswick, vol. 4, pt. 4, No. 19, 1901, pp. 269-286: New
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1901b. Bulletin of the Natural History Society of New Brunswick, vol. 4, pt. 4, No. 19, 1901 (Jan.), pp. 303-304:
Acrothyra, a new genus of Etcheminian brachiopods.

1901c. Proceedings and Transactions of the Royal Society of Canada for 1901, 2d ser., vol. 7, sec. 4, No. 8, 1901,
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1902a. The Canadian Record of Science, vol. 8, No. 7, 1902 (Jan.), pp. 437-470: Ostracoda of the basal Cambrian
rocks in Cape Breton.

BIBLIOGRAPHY. 2]

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22 CAMBRIAN BRACHIOPODA.

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Repuicu, K. A.:.
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BIBLIOGRAPHY. 23

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24 CAMBRIAN BRACHIOPODA.

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e

BIBLIOGRAPHY. 25

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1889a. The American Journal of Science, 3d ser., vol. 37, 1889 (May), pp. 374-392: Stratigraphic position of the
Olenellus fauna in North America and Europe.
1889b. The American Journal of Science, 3d ser., vol. 38, 1889 (July), pp. 29-42: Stratigraphic position of the
Olenellus fauna in North America and Europe.
1889c. Proceedings United States Museum for 1888, vol. 11, 1889 (Sept. 3), pp. 441-446: Description of new genera
and species of fossils from the Middle Cambrian.
1890a. The American Journal of Science, 3d ser., vol. 39, 1890 (Feb.), pp. 101-115: A review of Dr. R. W. Ell’s
Second report on the geology of a portion of the Province of Quebec; with additional netes on the ‘‘Quebec
group.”
1890b. Proceedings United States National Museum for 1889, vol. 12, 1890 (Feb. 5), pp. 33-46: Descriptive notes
of new genera and species from the Lower Cambrian or Olenellus zone of North America.
1890c. Proceedings United States National Museum for 1890, vol. 13, 1890 (Oct. 14), pp. 267-279: Description of
new forms of Upper Cambrian fossils.
1891a. Tenth Annual Report United States Geological Survey, 1890, pt. 1, pp. 509-774: The fauna of the Lower
Cambrian or Olenellus zone. (This report is dated 1890, but was not issued until well along in 1891.)
1891b. Bulletin United States Geological Survey No. 81, 1891: Correlation papers—Cambrian.
1897a. The American Journal of Science, 4th ser., vol. 3, 1897 (May), pp. 404-405: Note on the genus Lingulepis.
1897b. Proceedings United States National Museum, vol. 19, 1897 (Aug. 27), pp. 707-718: Cambrian Brachiopoda:
Genera Iphidia and Yorkia, with descriptions of new species of each and of the genus Acrothele.
1898a. The American Journal of Science, 4th ser., vol. 6, 1898 (Oct.), pp. 327-328: Note on the brachiopod fauna
of the quartzitic pebbles of the Carboniferous conglomerates of the Narragansett Basin, Rhode Island.
1898b. Proceedings United States National Museum, vol. 21, 1898 (Nov. 19), pp. 385-420: Cambrian Brachiopoda:
Obolus and Lingulella, with description of new species.
1899. Monographs United States Geological Survey, vol. 32, 1899; Geology of the Yellowstone National Park,
pt. 2, pp. 440-466: Cambrian fossils.
1900. Proceedings of the Washington Academy of Sciences for 1899, vol. 1, 1890 (Feb. 14), pp. 301-339: Lower
+ Cambrian terrane in the Atlantic province.
1901. Proceedings United States National Museum, vol. 23, 1901 (May 22), pp. 669-695: Cambrian Brachiopoda:
Obolella, Subgenus Glyptias; Bicia; Obolus, Subgenus Westonia; with descriptions of new species.
1902. Proceedings United States National Museum, vol. 25, 1902 (Nov. 3), pp. 577-612: Cambrian Brachiopoda:
Acrotreta; Linnarssonella; Obolus; with descriptions of new species.
1905a. Proceedings United States National Museum, vol. 28, 1905 (Feb. 17), pp. 227-337: Cambrian Brachiopoda,
with descriptions of new genera and species.
1905b. Proceedings United States National Museum, vol. 29, 1905 (Sept. 6), pp. 1-106: Cambrian faunas of China.
1906. Proceedings United States National Museum, vol. 30, 1906 (May), pp. 563-595: Cambrian faunas of China,
paper No. 2
1908a. Smithsonian Miscellaneous Collections, vol. 53, Cambrian Geology and Paleontology, No. 1, 1908 (Apr. 18),
pp. 1-12: Nomenclature of some Cambrian cordilleran formations,
1908b. Smithsonian Miscellaneous Collections, vol. 53, Cambrian Geology and Follsonuclaeyy, No. 2, 1908 (Apr. 25),
pp. 138-52: Cambrian trilobites.
1908c. The Canadian Alpine Journal, vol. 1, No. 2, 1908 (Sept.), pp. 232-248: Mount Stephen rocks and fossils.
1908d. Smithsonian Miscellaneous Collections, vol. 53, Cambrian Geology and Paleontology, No. 3, 1908 (Oct. 1),
pp. 53-137: Cambrian Brachiopoda; descriptions of new genera and species.
1908e. Smithsonian Miscellaneous Collections, vol. 53, Cambrian Geology and Paleontology, No. 4, 1908 (Oct. 13),
pp. 138-165: Classification and terminology of the Cambrian Brachiopoda.
1908f. Smithsonian Miscellaneous Collections, vol. 53, Cambrian Geology and Paleontology, No. 5, 1908 (Nov.),
pp. 167-230: Cambrian sections of the Cordilleran area.

26 CAMBRIAN BRACHIOPODA.

Wa.erivs, I. D.:
1895. Undersékningar 6fver Zonen med Agnostus levigatus i Vestergotland, etc.; 1895. 8°. Lund.
WEED, W. H.: ;
1900. Twentieth Annual Report United States Geological Survey, 1900, pt. 3, pp. 257-461: Geology of the Little
Belt Mountains, Montana.
WELLER, STUART:
1903. Geological Survey of New Jersey, Report on paleontology, vol. 3, 1903: The Paleozoic faunas.
WESTERGARD, A. H.:
1909. Meddelande fran Lunds Geologiska Faltklubb, Ser. B, No. 4 (Aftryck ur Kongl. Fysiografiska Sallskapets
Handlingar, N. F., Bd. 20), 1909, pp. 1-79: Studier diver Dictyograptusskiffern och dess granslager med
Sarskild hinsyn till i Skane forekommande bildningar.
WaHire, C. A.:
1874. Geographical and Geological Explorations and Surveys West of the One Hundredth Meridian, Preliminary
report upon invertebrate fossils, 1874 (Dec.), pp. 5-27.
1877. Report upon United States Geographical Surveys West of the One Hundredth Meridian, vol. 4, pt. 1,
Paleontology, 1877, pp. 1-219. ;
1880. Proceedings of the United States National Museum, vol. 3, 1880 (May 6), p. 47: Note on Acrothele.
WHITEAVES, J. F.: F
1878. The American Journal of Science and Arts, 3d ser., vol. 16, 1878 (Sept.), pp. 224-226: On some Primordial
fossils from southeastern Newfoundland.
WHITFIELD, R. P. (see also Hatt and WHITFIELD):

1862. The American Journal of Science and Arts, 2d ser., vol. 34, 1862 (July), p. 186: Note on the description of

Lingula polita.
1875. Report of a reconnaissance of the Black Hills of Dakota, made in 1874, by William Ludlow, 1875, pp. 103-
104: Descriptions of new fossils.
1877. United States Geographical and Geological Survey of the Rocky Mountain Region: Report on the geology
of the Black Hills of Dakota, Preliminary Report, 1877.
1878. Annual Report of the Wisconsin Geological Survey for 1877; 1878, pp. 50-89: Preliminary descriptions of
new species of fossils from the lower geological formations of Wisconsin.
1880. United States Geographical and Geological Survey of the Rocky Mountain Region; Report on the geology
and resources of the Black Hills of Dakota, by Newton and Jenney, 1880, pp. 329-468: Paleontological
report. .
1882. Geology of Wisconsin, vol. 4, 1882, pt. 3, pp. 161-363: Paleontology
1884. Bulletin of the American Museum of Natural History, vol. 1, No. 5, 1884 (Feb. 13), pp. 139-154: Notice
of some new species of Primordial fossils in the collections of the museum, and corrections of previously
described species.
1886. Bulletin of the American Museum of Natural History, vol. 1, No. 8, 1886 (Dec. 28), pp. 293-345: Notice
of geological investigations along the eastern shore of Lake Champlain, with descriptions of neay fossils.
Wiis, Bartey, and BLACKWELDER, ELioT: 4
1907. Carnegie Institution of Washington. Research in China, vol. 1, 1907 (Apr.), chap. 6, pp. 99-152: Stratigra-
phy of western Chili and central Shansi.
Wiman, C.: ;
1902. Bulletin of the Geological Institution of the University of Upsala, vol. 6, pt. 1, No. 11, 1902, pp. 12-76:
Studien tiber das nordbaltische Silurgebiet.
WINCHELL, A.:
1864. The American Journal of Science and Arts, 2d ser., vol. 37, 1864 (Mar.), pp. 226-232: Notice of a small
collection of fossils from the Potsdam sandstone of Wisconsin and the Lake Superior sandstone of Michigan.
WINCHELL, N. H.: y ;
1886. Fourteenth Annual Report of the Geological and Natural History Survey of Minnesota for 1885; 1886, pp.
313-318: New species of fossils.
WINCHELL, N. H., and ScHucHeErt, C.:
1895. The Geological and Natural History Survey of Minnesota, The geology of Minnesota, vol. 3, pt. 1, Paleon-
‘tology, 1895, pp. 333-474: The Lower Silurian Brachiopoda of Minnesota.
WysoGorskI, JOHANN:
1900. Zeitschrift der deutschen geologischen Gesellschaft, Bd. 52, Hit. 2, 1900, pp. 220-226: Zur Entwicklungs-
geschichte der Orthiden im ostbaltischen Silur.
ZitTEL, K. A. von:
1880. Handbuch der Palzeontologie, Bd. 1, Palzeozoologie, Abth. 1, 1880. 8°. Mimchen und Leipzig.

a Since this reference was made and used in the monograph it has been noticed that the section on the Paleoze*c (pp. 136-152) is credited to
Blackwelder.

CAMBRIAN BRACHIOPODA. 27

SYNONYMIC REFERENCES.

The following table contains, arranged alphabetically by genera, subgenera, species, and
varieties, a list of the Brachiopoda referred to in this monograph, as they occur in the litera-
ture, and gives the present reference of each:

Inst, by genera, subgenera, species, and varieties, of the references given in the synonymy, with the present reference of each.

5 A.
Present reference.
abavia [Acrothele], Matthew [1902b, pp. 398-400]. ......-..--.----------- Acrothele avia.
Martithews [19035 pp LO0=10i)i= 2222-2224 22e2 see e- Do.
abnormis [Syntrophia], Walcott [1905a, pp. 289-290]...--.--.-------------- Huenella abnormis.
acadica [Obolus], Walcott [1905a, pp. 324-325]....-....-.-..-------------- Obolus acadicus.
NC EICISMD alle [MS Taap tll| eceeeces Sete 2 enone eo ela See ar Obolus (Acritis).
Opnileath (MUSE oy AL eee re en tN ORC ee To a Do.
Wolllnerailn |fXR), (0id5 PA RPNI||pcaccssoncacccacoscccoccuccesancocacs Do.
(Acritis) [Obolus], Mickwitz [1896, pp. 205-206].....-...---.------.------- Do.
Wiallcotty [190s 683i] sao seers eee eee ere Do.
Walcott [1908e, Pl. XI, and pp. 142 and 144]........... Do.
Acritis antiquissima Gagel [1890, p. 22].---.-..-----------------+---------- Obolus (Acritis) antiquissimus.
Halland @larke) [18 92.chp a S2) bese aae eee eee eee esas Do.
Wolloontin |TMECY), joo, PIZRPIM| |. socacaccusascacsesesase Do.
(Acritis) antiquissimus [Obolus], Mickwitz [1896, pp. 206-213].....-.....-- Do.
(Acritis) antiquissimus ventrosus [Obolus], Mickwitz [1896, pp. 213-214]. . Do.
(Acritis?) rugatus [Obolus], Walcott [1901, p. 694]..........-------------- Obolus (Acritis?) rugatus.
Aeroiheles ayvidcons | 1883) pp. 215-214) eee eee ee eee see Acrothele.
Grain! eel Sorrenere [MO 5 AN scscoscasssanessscsbseosscces Do.
Hall and Clarke [1892a, pp. 249-250]. ......-.-.--------------- Do.
Hall and Clarke [1892b, pp. 565-566].-..-.-.------------------ Do.
Hall and Clarke [1892c, pp. 98-101]. ....-...--..-------------- Do.
Ibauonmenigstorn |[IUSTAG, Toa. AOS cosa ceosesescscocaceeseseesssa5e- Do.
Maine? [ICOR, joo. UOBANOS || oo csocsccsecccsosecssscoesoecceas Do.
Oalallercti MA, jogs WE SIMO sccnecaesoasecsnesescuusscsacunes Do.
Wealleoiitt [IGT jo. MOVAMOS)socseccsccebeccccscccoccccseacssee Do.
Walcott [1908e, Pl. XI, and pp. 142 and 146] a ees Lee pera eevons ee Do.
AItvela SSO ss psiGGO) jackasses == sane He sense ects oe eine Do.
Acrothele abavia Matthew [1902b, pp. 398-400]. ...........-..-.--------- Acrothele avia.
Wiener? [MOR joie. WOOO |. -os-5eseetot dec csonetesoe Do.
Acrothele artemis Walcott [1908d, p. 82].---.--.------.----------------:-- Acrothele artemis.
Acrothele avia Matthew [1899b, pp. 202-203]. ......-.-......------------ Acrothele avia.
Matthew [1902b, pp. 396-398].-.......---...-..-.--.-.----- Do.
Matthew, [19035 ppsod)and!98=99) eee seee sess eee eee Do.
Acrothele avia-puteis Matthew [1902b, p. 398].--........-.--------------- Acrothele avia puteis.
Matthews [903% ios 00)] Baeesae eee teeter ierr Do.
Acrothele barbata Moberg and Segerberg [1906, pp. 67-68].....--..--.--.--- Acrothele ceratopygarum.
Acrothele bellapunctata Walcott [1908d, pp. 82-83]. ......-...-.---.----- Acrothele bellapunctata.
Acrothele bellula Walcott [1897b, pp. 716-717]....-...-...--..----------- Acrothele bellula.
Acrothele bergeroni Walcott [1908d, pp. 83-84]...-.-..-..--..------------ Acrothele bergeroni.
Acrothele bohemica Hall and Clarke [1892c, p. 101]..-....-....-...------- Acrothele bohemica.
Pompeckj [1896b, pp. 509-511]...-...-..---.-..---.- Do.
Woalleattt (MSI, ds WOM oscksocsecusesccc-ossenssaseq Do.
Acrothele borgholmensis Walcott [1908d, pp. 84-85]........--....---.---.- Acrothele borgholmensis.
Acrothele ceratopygarum Moberg and Segerberg [1906, p. 67]-..---..---.-- Acrothele ceratopygarum.
Acrothele ceratopygonum Walcott [1902, p. 598]...-.-.----.-.-..---------- Do.
AGrotwelercollenimwWalcotninewleseess-ee-ae-ceee eee renee eee eee eee. Acrothele colleni.
Werotheleconacebror ren sis ips Olleseeesee seen aeeeceeer eae eee eee = Acrothele coriacea.
Acrothele coriacea Grénwall [1902, p. 40]........-...---------------..--- Do.
ILpravornisstorn |S, joes AUP |o--occoseon se ececnecece=se5 Do.
Acrothele decipiens Walcott [1897b, p. 716]....--..----.--...-..---------- Acrothele decipiens.
Acrothele? dichotoma Walcott [1884b, pp. 14-15].-.........-....-..--.--- Acrothele dichotoma.
Acrothele gamagei Grabau [1900, pp. 615-617]...............-.--.-..---- Acrothele gamagei.
Grabanbandysbimider) (9 07es ps2 00) eae eee Do.

Slammers [MOOS joo. nO eum! W/\seec obs scesoscessce oes Do.

28 CAMBRIAN BRACHIOPODA.

Present reference.

Acrothele granulata Davidson [1883, p. 214]:.........-.-..-.------------ Acrothele (Redlichella) granulata.
Hall and Clarke [1892c, pp. 100-101]..-.........-..--. Do.
Wrlnatenyststorn | MEWS, (Os 2H! Lescocondes osecoocsuccocase-ce Do.
Linnarsson [1877, pp. 373-374]...-...-.-.-.-.--------- Do.
Swanston [1877, Pl. VII, fig. 20a—-c] -..:.--..---....-- Do.
Swanston [1886, Pl. VII, fig. 20a-c].......-.-..-.----- Do.
Wrallcotta SS 6losmo sel O9)| sees ee eee Do.
Acrothele inchoans Matthew [1902b, p. 404]........................--.-..-Acrotreta inchoans.
Wien sey [OS 10 MWOB|E Ss eocasosdeaeoaeooceascusacacc Do. 7
Acrothele intermedia Gronwall [1902, p. 39].-.---.-..-.--.--------------- Acrothele intermedia.
Linnarsson [1879, pp. Aa SNe rae Aen eS Do.
Acrothele levisensis Walcott [1908d, p. 85]-. Lise ..---.---Acrothele levisensis.
Acrothele matthewi Grabau and Shimer [1907, p. “200, “ay. 234]. eaeeiesisienee Acrothele matthewi.
Grabau and Shimer [1907, p. 200, fig. 234¢]...-.....-. Acrothele prima.
Hall and Clarke [1892a, Pl. IIT, Ae. QANe cee 5 aseeoseee Acrothele matthew1.
“Halland Clarke [1892c, pp. 99 and 100].............. Do.
Matthew [1886, pp. 39-41]_.......................... Do. .
Wiiia@yy (TUE, > WAN. csossscceesocsecocsacenease Do.
Matthew [1902b, pp. 397 and 402].-......-..-..-.--.- Do.
Matthews (903 "ioral 04] Gee eee ee eee sence ee Do.
Wealleoritr (ISIE (0), U5) --seccsacessesceedoccce Seow Do.
Weile@uit (UEEIBO. D> MOO resacacasascoasaesacaascasesess Do.
Wallets (Mein, jo, GUY) 2sssscosesteccssccacsossacuacae Do.
Acrothele matthewi costata Matthew [1895a, p. 128]..............- eee: Acrothele prima costata.
Matthew [1902b; p. 397]. -22---24--45-2------- Do.
Matthew [1903 p. 104).....-.-..--....-2.---- Do.
Acrothele matthewi eryx Walcott [1905b, p. 11]...--.-.-.------.---.----- Acrothele matthewi eryx.
Acrothele matthewi lata Hall and Clarke [1892a, Pl. III, figs. 25 and 26]. .Acrothele matthewi lata.
Hall and Clarke [1892c, Pl. III, figs. 26— oe Besace Do.
Matthew [1886, p. 41].- eee sem ialnae Uhlee Do.
Matthew [1895a, Pl. V, fags, Seb. sac m steele Do.
Matthew [1903, p. 104]... Iannis sb eretoraneletania Do.
Acrothele matthewi multicostata Matthew [1897b, } i ). 168]... Weel iS i atl SRO Acrothele matthewi multicostata.
Acrothele matthewi prima Hall and Clarke [1892a, Pl. III, fig. 27]......... Acrothele prima.
Hall and Clarke [1892c, Pl. III, fig. se Baers Stas Do.
Matthew [1886, p. 41]-- 5 atheists Do.
Matthew [1895a, Pl. V, figs. ‘Ta lk. sesoe esse Se Do.
Matthew [1902b, pp. 397 and 402]...........-.-- Do.
Matthew [1903, p. 104]................--------- Do:
Acrothele? minuta Walcott [1905a, p: 303]--------..----------+--------- Acrothele? minuta.
Acrothele panderi Walcott [mew] .......-.------------------------------- Acrothele panderi.
Acrothele pretiosa Walcott [1898b, p. 402] -...-.----- SE ey SEAS Acrothele pretiosa.
Acrothele primeva Pompeckj [1896b, p. 603]......-...-----.-------------- Acrothele primeva.
‘Acrothele proles Matthew [1902b, pp. 400-401]........-....--.------------ Acrothele proles.
Matthew [1903, pp. 60 and 102-103].-.....-...-..-.-.---- Do.
Acrothele quadrilineata Pompeckj [1896b, p. 511].--.--....--...-------.-- Acrothele quadrilineata.
Acrothele rarus Walcott [1905a, pp. 303-804]....................--..-..... Acrothele rara.
Acrothele spurri Walcott [1908d, pp. 86-87]...-..-..---.----------------- Acrothele spurri.
Acrothele subsidua Beecher [1891, Pl. XVII, fig. 12]--.....-..--..-.------ Acrothele subsidua.
Grabau and Shimer [1907, p. 200]........-.....-.----- Do.
Hall and Clarke [1892c, pp. 100 and 103]........-...-.- Do.
Meine [IIOAE 19> WO] ons-sescsckeseas ses secronsene Do.
Wien oene (MIQUE, jos NOBIS Lsocacstadenssddsocecposamecaw Acrothele spurri.
Walcott [1886b, pp. 108-109, Pl. IX, figs. 4a-c]........- Acrothele subsidua. The paragraph on

page 109 includes reference to this species

and to Acrothele spurri.

Walcott [1886b, p. 109, Pl. IX, fig. 4]..................Acrothele spurri. The paragraph on page
j : y 109 includes reference to this species and

to Acrothele subsidua.

Walcott [1891a, p. 608, Pl. LXX, fig. 1]........-.-..--- Acrothele spurri. The text includes refer-
ence to this species and to Acrothele sub-

sidua.

Acrothele subsidua Walcott [1891a, pp. 608-609, Pl. LXX, figs. la-c]

White [1880, p. 47]
Acrothele subsidua hera Walcott [1908d, p. 87].........------------------
Acrothele subsidua leevis Walcott [new]

SYNONYMIC REFERENCES.

Acrothele turneri Walcott [1908d, pp. 87-88]..-..--.---------------------

Acrothele villaboimensis Delgado [1904, p. 365]
Acrothele woodworthi Walcott [1908d, p. 88]...

Acrothele yorkensis Walcott [1908d, pp. 88— 89).
Acrothele sp. undt. Walcott [new]

Acrothele sp. Moberg [1892b,

Pompeckj [1896b, p. 603]

Acrothele (Redlichella) Walcott [1908d, pp. 89-90]
Walcott [1908e, Pl. XI, and pp. 142 and 146]
Acrothyra Matthew [1901b, pp. 303-304]

Matthew [1902c, p.
Matthew [1903, pp.

Matthew [1903, pp.

Walcott [1908e, Pl.
Acrothyra? inflata Matthew [1901b, p. 304]
(Acrothyra?) inflata [Lingulella], Matthew [1902b, p. 390]
Acrothyra minor Walcott [1905a, p. 303]
Acrothyra proavia Matthew [1902b, pp. 386- 388]...
Matthew [1903, pp. 53-55]

Acrothyra proavia crassa Matthew [1902b, pp. 389-390]
Matthew [1903, p. 94]

Acrothyra proavia prima Matthew [1901b, p. 303].

pp. 114-115]

104]
85-86]
88-89]
XI, and pp. 142 and 146]

Matthew [1902b, p. 389]. -

Matthew [1903, pp. 58, 86, aad 93].

Acrothyra signata Matthew [1902b, pp. 381-382]
Matthew [1903, p. 87]

Acrothyra signata orta Matthew [1902b, pp. 385-386]
Matthew [1903, pp. 89-90]

Acrothyra oe prima Matthew [1902b, pp. 382-383]
Matthew [1903, p. 73]

Acrothyra (signata) sera Matthew [1902b, pp. 383-384]
Acrothyra signata sera Matthew [1903, p. 56]
Matthew [1903, pp. 87-88]

Acrothyra signata tarda Matthew [1902b, pp. 384-385]
Matthew [1903, p. 89]

Acrotreta Dall [1877, p. 12].--
Davidson [1853, p. 133]
Davidson [1871, p. 343]

Grabau and Shimer

Hall and Clarke [1892a, p. 250]

Hall and Clarke [1892b, p. 566]

Hall and Clarke [1892c, pp. 101-104]

Kutorga [1848, pp. 259, 260, and 275]

Matthew [1902b, p.
Matthew [1903, pp.

Morris [1849, pp. 316 and 318]
Oehlert [1887, p. 1266]

von Seebach [1865,
Walcott [1884b, pp.

Walcott [1908e, Pl. XI, and pp. 142 and 146]

Zittel [1880, p. 666]

Acrotreta argenta Wallon (UQO2, jojo. GOI oe oc ceecee eannsnese access
Acrotreta attenuata Meek [1873, p. 463]

Walcott [1905a, p. 298]

[GO <0] ieee cine Malate dy mtan ee

390]
94 and 96-97]

p. 341]
16-17]

29

Present reference.

-Acrothele subsidua. The text includes
reference to this species and to Acrothele
spurri.

Acrothele subsidua.

-Acrothele subsidua hera.

Acrothele subsidua leevis.
Acrothele turneri.
Acrothele villaboimensis.

.-Acrothele woodworthi.

Acrothele yorkensis.

Acrothele sp. undt. a.

Acrothele sp. undt. b.

Botsfordia? barrandei (in part) and Acro-
thele bergeroni (in part).

Acrothele (Redlichella).

Do.
Acrotreta inflata.

Do.
Acrothyra minor.
Acrothyra proavia.

Do.

Do.

Do.

Do.

Do.

Do. ;
Acrothyra signata.

Do.
Acrothyra signata orta.

Do.
Acrothyra signata prima.

Do.
Acrothyra sera.

Do.

Do.

Do.

Do.
Acrotreta.

Do.

Do.

Do.

Do.

Do.

Do.

Do.

Do.

Do.

Do.

Do.

Do.

Do.

. Do.
Do.

-Acrotreta argenta.

Acrotreta attenuata (in part), A. attenuata
var. (in part), and A. idahoensis (in part).
Acrotreta attenuata.

30

Acrotreta attenuata var.? Walcott [1905a, p.
Acrotreta babel Barrande [1879b, Pl. XCV,

298) sere eeermaes = eh ae
fiess vin; U2) esse. sae

Acrotreta baileyi Hall and Clarke [1892a, Pl. III, figs. 28-30] .-..--

CAMBRIAN BRACHIOPODA.

Present reference.
Acrotreta attenuata var.?
Acrotreta babel.
Acrotreta baileyi.

Hall and Clarke [1892c, p. 102]-.-.:--.-.-----.---------- Do.
Matthew, [S865 ppi36—3il|ses= eee eeeee een eee ee Do.
Matthews [1902p Nips 395) pees seen eases: eee eee Do.
Matthew, [19035 ps OMe a-sclae s eases ae eee eens Do.
Walcott) [T902 ip psusl—582] pases sees eee sees eres Do.

Acrotreta baileyi? Matthew [1892) p. 43]--..--.---..2--.-----22-----3---
Acrotreta bellatula Walcott [1908d, pp. 93-94].......-..--.-.....--
Acrotreta bisecta Matthew [190la, pp. 275-276]. ....--...---.-----
Matthew: [i902 spac 94| ees see eee eee eee eee
Matthew [19035 pp. L86=U87)- == =2--2--252------:
Wallecott) (902% peo82)|Reeess- sass see Bes reteee esas a

a

Walcott [1905a, pp. 298=299]...................-
Acrotreta? cancellata Walcott [1905a, p. 299]-- LER aa ASRS
Acrotreta carinata Moberg and Segerberg (1906, Pp. >. 66] Peery Ate tec
(Acrotreta?) ceratopygarum [Discina], Brogger [1882, p. 47] ..-----
Acrotreta circularis Moberg and Segerberg [1906, pp. 65-66] - - sos
Acrotreta claytoni Walcott [1902, p. 583]. ....-...-.:.-.--.-------...-.--
Acrotreta concentrica Walcott [1902, p. 583]..-..-.-----------------------
Acrotreta conula) Walleout [19025 ps 084 peessesseeees eae eee ae eee ee ease ee
Acrotreta convexa Walcott [1902, p. 584]....-..-....------....--- Beem
Acrotreta cunvata Walcott [L902 sps 584 sess sess see eee ae eee eee
Acrotreta definita Walcott [1902, pp. 584-585].-....--.-..------.----
Acrotreta depressa Walcott [1908c, p. 245]..-........----.---------------

Acrotreta dichotoma Hall and Clarke [1892c,

pp. 100 and 103]. - ---

Acrotreta bisecta.
Acrotreta bellatula.
Acrotreta bisecta.

Do.

Do.

Do.

Do.

_.Acrotreta?? cancellata.

Acrotreta carinata.
Acrothele ceratopygarum.

.-Acrotreta circularis.

Weleouis |MEtI8)), 10. WOAsescessosese5 sassesassesossce

Acrotreta eggegrundensis Walcott [1905a, pp. 299-300]......-...-...-..--.

Avahoaraay (OW 10> Bl bencadasdsdaccogascsdosacacsc

Acrotreta emmonsi Walcott [1905a, p. 300].-.-.--.------------------------
1 AR eS es 2a

Acrotreta gemma Billings [1865a, pp. 216-21
Grabau and Shimer [1907,
Hall and Clarke [1892c, p.
Hall and Clarke [1892c, p.
Walcott [1884b, pp. 17-18]

Walcott [1884b, pp. 17-18,
Walcott [1884b, pp. 17-18,
Walcott [1886b, pp. 98-99]

Walcott [1886b, pp. 98-99,

DrAGO | een cee

102, Ae, Bloc cc secneses

102, figs. 56 and 57]...

Acrotreta claytoni.
Acrotreta concentrica.
Acrotreta conula.
Acrotreta convexa. *
Acrotreta curvata.
Acrotreta definita.
Acrotreta depressa.
Acrothele dichotoma.
Do.

_Acrotreta eggeerundensis.

Do.

.Acrotreta emmonsi.

Acrotreta gemma.
Acrotreta primeeva.
Acrotreta curvata.
Acrotreta idahoensis alta.

L SNe eG merbem es Me OeC eee eae Acrotreta attenuata (in part), A. pyxidi-

PIR icsala—b)| ee eeeeeeeeeee

Pl. I, figs. ld-e] .....-

cula (in part), A. curvata (in part), and
A. idahoensis alta (in part). The text.
includes all four species, but the last two
were the only ones figured.

Acrotreta idahoensis alta.

Acrotreta curvata.

SEAS See Sete ....----Acrotreta attenuata (in part), A. pyxidi-

Pl. VIII, figs. 1, la-b]

Walleoits Weil, jo, GUSI> -2cessceseoccasesescecsebesess

Walcott [1891a, p. 608, Pl.

Walcott [1891a, p. 608, Pl. LX VII, fig. 5b]...-.......--- Acrotreta curvata.
Walcott [189la, p. 608, Pl. LX VII, 5c-e]-.-..=--2-...-- Acrotreta primzva.
Walcott M899 sr 440) cose es Sees Secs a oeeaey eee Acrotreta attenuata (in part), A. pyxidi-

Walcott [1899, p. 449, Pl. LXII, figs. 2, 2b, and 2d]

LXVII, figs. 5 and 5a]

cula (in part), and A. primeeva (in part).

The text includes all three species, but.

the last was the only one figured.
Acrotreta primzva.

Acrotreta attenuata (in part), A. pyxidi-

‘cula (in part), A. curvata (in part), A.

idahoensis' alta (in part), and A. pri-

meya (in part). The text includes all

five species, but the last three were the
~ only ones figured.

Se eee se Acrotreta idahoensw alta.

cula (in part), A. curvata (in part), A.
idahoensis alta (in part), and A. pri-
meeva (in part). The text includes all
five species, but the last three were the
only ones figured.

BEN Pc Acrotreta primzeva.

SYNONYMIC REFERENCES. 31

Acrotreta gemma Walcott [1899, p. 449, Pl. LXII, figs. 2a and 2c]
Walcott [1899, p. 449, Pl. LXII, fig. 2e].........-

Acrotreta gemma depressa Matthew [1902c, p. 109]..---..----------
Walcott [1889c, pp. 441-442]............

Acrotreta gemmula Matthew [1894, pp. 87-88]. ........-..--------
Matthew: [18 95a; sp sl2 6 peseeee een eeee a aeeeeee

; Wien oveNy? WES Tos Cl Kocacsaceuooscocdeococesaasnsaqce

Acrotreta gracia Walcott [1902, pp. 586-587]..........---.---------
Acrotreta? gulielmi Matthew [1886, pp. 37-39].....-..---.--------
Acrotreta idahoensis Walcott [1902, p. 587]. .-----...-------------
Acrotreta cf. idahoensis Walcott [new] ..............--------------
Acrotreta idahoensis alta Walcott [1902, p. 588].....-...-..--------
Acrotreta idahoensis sulcata Walcott [1902, p. 588].-.--.--.--------
Acrotreta inchoans Pompeckj [1896a, p. 3].-.-....-....-----------
Acrotreta inflata Walcott [1902, pp. 588-589].........--------------
Acrotreta kutorgai Walcott [1902, pp. 589-590].........-.-..-..----

Acrotreta liani Walcott [1905a, p. 300]..........-..--.....----.---
Acrotreta liméensis Wiman [1902, p. 54]............-.....--------
Acrotreta marjumensis Walcott [1908d, pp. 94-95].-..-.--.-.---------
Acrotreta microscopica missouriensis Walcott [1902, p. 590].-..---.-.-----
Acrotreta microscopica tetonensis Walcott [1902, p. 590].....------
Acrotreta minuta Walcott [1901, p. 673]......--....--.------------
Acrotreta miser Walcott [1902, pp. 590-591].-..- Fe RI Ree
Acrotreta neboensis Walcott [1905a, pp. 300-301]-..---...--..------
Acrotreta? nicholsoni Davidson [1868, pp. 313-314].......--..-.----
Davidson [1871, pp. 348-344]...............-

Acrotreta nicholsoni Davidson [1883, p. 213].........-.-----------
Hall and Clarke [1892c, p. 103]......--.-------

Swanston [1877, Pl. VII, figs. 2la-c]...-.-...--

Swanston [1886, Pl. VII, figs. 2la-c]......-..--

Acrotreta sp. cf. nicholsoni Matley [1902, p. 142] ..........-.---.--
Acrotreta nox Walcott [1905a, p. 301].............---.------------
Acrotreta celandica Westergard [1909, p. 76] .-....-....--.----.----
Acrotreta ophirensis Walcott [1902, pp. 591-592]. .......---..---.-
Acrotreta cf. ophirensis Walcott [new].......---..--------------

Acrotreta ophirensis descendens Walcott [1908d, p. 95]. -.......--
Acrotreta ophirensis rugosus Walcott [1902, p. 592]...-.......---.-
Acrotmeta ovalis) Walcobt [902% jp. S92) es2.--s-sees2eee ee eae ese =
Acrotreta pacifiea Walcott [1905a, p. 301]...--...-..--.-..--.------
Acrotreta papellata-prima Matthew [1902b, pp. 391-392].........--
Acrotreta papillata Matthew [1902b, pp. 390-391]..-..-...--...-----

JNGKONTEIA) JOAIAADIE) \Welkeott [OZ TOs BSI6 soconconccsdesscoeacc2seosaacosc
Acrotreta primazea Walcott [1902, p. 593] -........--.-------------
Acrotreta proavia Matthew [1899b, p. 203].....-.....----..--.----
Acrotreta pyxidicula White [1874, p. 9]...----...--------.-------
WViaie (WS 19s BE coscsccoceceaccrocecc

Acrotreta recurva Kutorga [1848, pp. 277-278]. .......---.--.-----
Acrotreta rudis Walcott [1908d, pp. 95-96]........--..--.----------
Acrotreta (?) sabrinze Matley [1902, p. 143] ........-.-......-------
Acrotreta (?) sabrinze malvernensis Matley [1902, pp. 143-144]
(Acrotreta?) sagittalis [Obolella], Moberg and Segerberg [1906, p. 64]
Acrotreta cf. sagittalis Walcott [new] ---..---..--.-----------------
Acrotreta sagittalis magna Walcott [1902, pp. 595-596]....-...-.-.........
Acrotreta sagittalis taconica Walcott [1902, pp. 596-597]. .....-.--.
Acrotreta schmalenseei Walcott [1902, pp. 597-598]........-.--.---
Acrotreta seebachi Moberg and Segerberg [1906, pp. 66-67]-......--
Walcott) [902 pp 598-599) saseeeeee meres teen e eae

Acrotreta shdntungensis Walcott [1905a, pp. 301-302]............/........
Acrotreta signalis Walcott [1902, p. 599]...-...-. Rte Tepneeeeletee

i re Acrotreta cf. idahoensis.

Present reference.

Rage on see Acrotreta idahoensis alta.

Acrotreta curvata.
Acrotreta depressa.
Do.
Acrotreta gemmula.
Do.
Do.
Acrotreta gracia.
Discinopsis gulielmi.
Acrotreta idahoensis.

Acrotreta idahoensis alta.

Acrotreta idahoensis sulcata.

Acrotreta inchoans.

Acrotreta inflata.

Acrotreta kutorgai (in part) and A. rudis
(in part).

_.....-Acrotreta lisani.
eee Acrotreta uplandica liméensis.

Acrotreta marjumensis.

-Acrotreta microscopica missouriensis.

Acrotreta microscopica tetonensis.

aay ests Linnarssonella minuta.

Acrotreta misera.
Acrotreta neboensis.
Acrotreta nicholsoni.

Do.

Do.

Do.

Do.

Do.
Acrotreta sabrine.
Acrotreta nox.
Acrotreta celandica.
Acrotreta ophirensis.
Acrotreta cf. ophirensis.
Acrotreta ophirensis descendens.
Acrotreta ophirensis rugosa,
Acrotreta ovalis.
Acrotreta pacifica.
Acrothyra sera.

Do.

Do.

Do.

Do.

Do.

-Acrotreta parvula.

Acrotreta primeva.

Acrothyra proavia.

Acrotreta pyxidicula.
Do.

Volborthia recurva.

Acrotreta rudis.

Acrotreta sabrine.
Do.

Acrotreta sagittalis.

voctare Acrotreta cf. sagittalis.
-Acrotreta sagittalis magna.

Acrotreta sagittalis taconica.
Acrotreta schmalenseei,
Acrotreta seebachi.

Do.

-Acrotreta shantungensis.

Acrotreta signalis.

a2 CAMBRIAN BRACHIOPODA.

Present reference.

Acrotreta sipo Matthew [1902b, pp. 406-407]...........--..-...--+.------ -Acrotreta bisecta.
WienAne 7 [LOS joies IESG). cescessoesecedsessoensaccdoce Do.
Acrotreta socialis Grénwall [1902, p. 39]. -..-...---- ISS b/c eee Hither Acrotreta schmalenseei or A. socialis.
e (See p. 712.)
Linnarsson [1876, pp. 16-18] ........-...-....-..--..----Acrotreta schmalenseei.
ibthaiaemEssora [US De BH sono scosasacanenas sacceccascawe Hither Acrotreta schmalenseei or A. soci-
alis. (Seep. 712.) ‘
Vou Siere) oe Vela [LILES Jo), SHEE os coscsososesaucnascsesocaee Acrotreta socialis.
Wallconty [9025p pers 99-600) Mees sere Do.
Waillerius) [S95 pr6G] etch e settee ere ere a ee Acrotreta schmalenseei.
Acrotreta cf. socialis Brégger [1882, pp. 46-47, Pl. X, figs. 2, 2a-b] ..----.- Acrotreta carinata.
Broégger [1882, pp. 46-47, Pl. X, figs. 3 and 4] ........Not referred in this monograph.
Matleya [9025 hop 44145) Bee ese e eee Acrotreta sabrine. a
Matthew [1902b, pp. 392-394].................-..---- Acrotreta sp. undt.
Matthew [1903, pp. 183-185]....--. NER? Ce aetna... Do.
Acrotreta spinosa Walcott [1905a, p. 302]............-...--.--.----:------ Acrotreta spinosa.
Acrotreta subconica Davidson [1853, Pl. IX, figs. 271-275] ...-.....-.....-- Acrotreta subconica.
IONE |S To) BB |swecoec sosgaasscescaaeadusacesc Do.
Meek: [N'873;p A463 both os asc sensor satan eee Acrotreta attenuata (in part), A. attenuata
j var. (in part), and A. idahoensis (in part).
Quenstedt [1885, p. 755]...-...-...---..--..--------.-Acrotreta subconica.
von seebachy [865.905.3041] assesses see sae eee Do.
Walcott [1902, pp. 600-601]_...-..........--.-..------ Do.
Acrotreta? subsidua White [1874, p. 6]...-...-- eee eee Acrothelemstbsrdtam
Warts |S, os BHR |os--caascsssdssssasssascesan Do.
Acrotreta ulrichi Walcott [1908d, pp. 96-97].....-...---...-----.--------- Acrotreta ulrichi.
Acrotreta uplandensis Walcott [1905a, p. 302]-..............------------- Acrotreta uplandies:
Acrotreta uplandica Wiman [1902, p. 54]_..-...-.-....-...--------------- Do.
Acrotreta uplandica limonensis Walcott [1905a, p. 303]...........--..----- -Acrotreta uplandica limGensis.
Acrotreta sp. Morris [1849, Pl. VII, figs. 4a-b] ........-.- ros Sister ero Acrotreta subconica.
Westersird [1909 spp. 57 and! 77)Pa= 22-222 s-ee se eee see oe ee Acrotreta sp. undt.
Acrotreta (Volborthia) Oeblert [1887, p. 1266]...........-...--.--------- Volborthia.
acuminata [Glossina], Hall and Clarke [1892a, Pl. I, figs. 10 and 11]....... Lingulella (Lingulepis) acuminata sequens.,
acuminata [Lingula], Billings [1863, p. 102].........--..--...--..-.------ Lingulella (Lingulepis) acuminata.
Claghoventan [MIG 105 US| oe sossbesecoescbasessesaes Do.
Chapman) [1864p els Ol seas eee ee eens Do.
@onrad [1839 io GAl echo elie sree eee tt eres Do.
IDjoanTn Oras; | SINS), (Os AVE pacoasscncocsecaaccesocsccscse Do.
EPA ISS eap Oleic ses cess. <cimel fe ree ye ae Do.
acuminata [Lingula (Glossina)], Hall and Clarke [1892c, Pl. I, figs.1 and 2]..Lingulella (Lingulepis) acuminata sequens.
acuminata [Lingulepis], Dwight [1886, p. 208]. ...............-...------- Lingulella (Lingulepis) acuminata.
Matthew [1895b, pp. 257=258]..............------ Do.
Sielanelagrt (MEO, 0. ZO |sceccosocceecccassasccsses Do.
Walcotty [WS9varpn404)] sesesee eee eee a aeeeesee Do.
acuminata meeki [Lingulepis], Delgado [1904, pp. 366-367]........-...--- Lingulella delgadoi.
acuminata sequens [Lingulella (Lingulepis)], Walcott [1908d, p. 72].-.---. Lingulella (Lingulepis) acuminata sequens.
acuminatus [Obolus (Lingulepis)], Walcott [1899, p. 443]..............--- Tingulella (Lingulepis) acuminata.
acuminatus [Obolus (Schmidtia)], Mickwitz [1896, pp. 179-183]. .-.-..--- Obolus (Schmidtia) acuminatus.
acuminatus alatus [Obolus (Schmidtia)], Mickwitz [1896, pp. 183-184]...... Do.
acuminatus humeratus [Obolus (Schmidtia)], Mickwitz [1896, pp. 184-186]. Do.
acuminatus meeki [Obolus (Lingulepis)], Walcott [1899, p. 444] ..........- Lingulella (Lingulepis) acuminata meeki.
acuminatus: subtriangularis [Obolus (Schmidtia)], Mickwitz [1896, pp.
TBGS1SM Shes Se ee oe seeteroaes See Se aoe eels oceanic ote eee ere Obolus (Schmidtia) acuminatus.
acutangula [Lingula], Roemer [1849, p. 420].-.......--......------------- Lingulella acutangula.
Roemer [852 ips 90)|eeeesscn-s eee aeee eee Do. A
acutangulus [Lingulepis], Schuchert [1897, p. 259]. .........---.-.------- Do.
acutangulus [Obolus (Lingulella)], Walcott [1898b, pp. 393 and 394, Pls.
PRONGV TMT sar GE NENG VET 2) AU CS ie Oe eR Secreta eee etre Do.
acutus [Obolus (Schmidtia) obtusus], Mickwitz [1896, pp. 172-173]... ---- Obolus (Schmidtia) obtusus.
advena [Obolus?], Barrande [1879b, Pl. XCV, fig. Iv] .---.----.----.------ Obolus? advenus.
zquiputeis [Obolus], Matthew [1902c, p. 94]....--..-.----------------- Obolus selwyni.
WiwilaeNy [MOR 7Os IG. oa ase sabes tsgeboseossese bn Do.
affinis [Lingulella?], Billings [1872b, p. 468]............--...-..--.------ Obolus (Lingulobolus) affinis.
Billings [1874, p. 67]. .-.-.----- ete ares le leh al aiekage Do. hig

affinis [Lingulella], Billings [1882, pp. 15-16] - - - -. epee see eth Uae eye (er eee Do.

SYNONYMIC REFERENCES. 33)

Present reference.

affinis [Lingulepis], Walcott [1889a, p. 381]........---------------------- Obolus (Lingulobolus) affinis.
affinis [Lingulobolus], Grabau [1900, pp. 621-622] . Boe eae see Do.
Matthew [1895b, pp. 261-262]. . Uy Gaerne serie Jiasecss Do.
affinis [Obolus (Lingulobolus)], Walcott [1898a, p. 327].........-.-----.-- Do.
affinis cuneata [Lingulobolus], Matthew [1895b, p. 262]....-...--.-.---.--- Do.
agnostorum [Lingula], Wallerius [1895, pp. 64-65]. ..........-.-.-.-.---- Lingulella agnostorum.
agreste [Orthis (Plectorthis)], Walcott, [1906, p. 570]. .-.--.-.-.---.------- Koorthis agreste.
alabamaensis [Iphidea], Walcott [1897b, pp. 713-714].-..-..---...-------- Micromitra alabamaensis.
alandensis [Obolus (Westonia)], Walcott [1905a, p. 334]. .......------.--Obolus (Westonia) dlandensis.
alata? [Kutorgina], Moberg [1892b, p. 113].....---.-.--....-...--------Belongs with an undetermined genus.
alata [Syntrophia], Walcott [1905a, p. 290]. ......-....--.--------------- Syutrophia alata.
alatus [Obolus (Schmidtia) acuminatus], Mickwitz [1896, pp. 183-184]... -. Obolus (Schmidtia) acuminatus.
alberta [Billingsella], Schuchert [1897, p. 158]. ........-.-.....-..------- Nisusia alberta.
alberta [Nisusia], Walcott [1905a, pp. 248-249]........................... Do.
Wailconty[S0Sehi pi 245] ease eere eer eee eae eee Do.
alberta [Orthisina], Matthew [1902c, p. 109]....-.-.....-.--.------------ Do.
\Welleoins [MUSEO oar” PAR ena soacanodosnsescdescsccces Do.
alta [Acrotreta idahoensis], Walcott [1902, p. 588]......--..--..---------- Acrotreta idahoensis alta.
ambigua [Billingsia?], Ford [1886a, p. 467]. ....-..--..--.---------1----- Elkania ambigua.
ambigua [Elkania], Ford [1886b, p. 325].......-.--.------------------- Do.
Halivandi@lanke[lS92cspa7el see eneeee eee reeereee Do.
ambigua [Obolella?], Walcott [1884b, pp. 67-68]. .........-..--..--.-.-- Do.
amii [Nisusia (Jamesella)], Walcott [1905a, p. 252]. ....--..--..---------- Nisusia (Jamesella) amii.
avoayole, [ILromle}, Talal (UGS, js WSS Sols asceso cease 4ssoccancadsasosoaae Lingulella ampla.
TS teh) RBS To os IOLA eee ontGaucacocacdédasodsoddcdaes Do.
Owen [i852 5p ao8si As. i\secee ria ayer e/-\e ee ees Do.
anaplayinewlellal Schuchent |11897, p. 257-2525. 22-2522 52222 -e sees Do.
amplus [Obolus (Lingulella)], Walcott [1898b, pp. 392 and 394, Pl. XXVIII]. _—Do.
anceps [Obolus], Walcott [1898b, pp. 388-389]. ..........-..-...--.----.- Obolus anceps.
ancilla [Lingula], Barrande [1879b, Pl. CXI, fig. vi] -...-..-----.-------- Obolus ? ancillus.
angulatus [Obolus (Schmidtia) crassus], Mickwitz [1896, pp. 193-194]. ....- Obolus (Schmidtia) crassus.
anomala [Billingsella?], Walcott [1905a, p. 230]...........---.------.---- Wimanella ? anomala.
Anomites lenticularis Wahlenberg [1821, pp. 66-67]......--..--.--------- Orusia lenticularis.
aamieiey (eimennl a) Resi limes) (S56 padi] ees eee ea ese eee Lingulella (Lingulepis) acuminata.
IDpmnAOMy [WEY TO; AGsile cca o aaccacesescadssteoscosces Do.
IDroawTaovarss [PMG Os Allo os aa Sacensecosssenssessacccse Do.
Fall S84, ppwd—4] ee se ssaleiee «oe eee ee seem eee Do.
BeteIIAN [EUS i192 04205 | eee Do.
Isa Mp eee Os 74lll een eaakess Ge Jeseuqcssencsauic Do.
Hayicleny(lS62 5p) eee neeidace Wace eee eee Do.
James [1895, p. 884]....----..---- = SEC Rs See eae Do.
Oyen [EEN os (0) Pees se seasecocscoessdoednGcssasanc Do.

Toes |IIBIL Ds SEO) aoe coaocseoussecooskssemsassussec Obolus (Westonia) rogersi.
antiquata [Camarella?], Hall and Clarke [1893b, pp. 220-221]. ............ Swantonia antiquata.
antiquata [Camarella], Walcott [1886b, pp. 122-123]... ..........-....... Do.

\Wanlkooite |MDIle, jo, GIB |oe ocsesescesscéoosecesacce Do.
antiquata [Camerella], Billings [1861b, pp. 10-11]. ..........-...-....... Do.
IBM lovers WEIGMO, Jo), WED) |s acosscasscsacosscesobosass Do.
Balllimes | (US62e hp 221 | Bee eee eee Do.
Baillimcs)|(WSG3 tea 29 0 SpA. | pee ee Do.
antiquata [Lingula], Emmons [1855, pp. 202-203]. --..-..-.-----.----...- Lingulella (Lingulepis) acuminata.
antiquata [Protorhyncha?], Schuchert [1897, p. 3384]. ................-.-. Swantonia antiquata.
antiquata [Swantonia], Walcott [1905a, pp. 296-297]. ........-........... Do.
antiquissima [Acritis], Gagel [1890, p. 22]...--..-.-..--.-....-.--.------ Obolus (Acritis) antiquissimus,
Hallvandi@larke![il8920p5182]] Sem see see eee Do.
Volborth 1869) pp. 212-217] 2222s. esses eee ae Do.

antiquissima [Aulonotreta], Hall and Clarke [1892a, figs. 246 and 247, p. 244] Do.
Halland Clarke [1892b, figs. 246 and 247, p. 560]. Do.

antiquissimus [Obolus], Hichwald [1859, Pl. XX XVII, figs. ae oe aie Do.

Hichwald [1860, pp. 928-929]. . See ane Do.
antiquissimus [Obolus (Acritis)], Mickwitz [1896, pp. 206-213] Soe see Do.
antiquissimus [Obolus (Lucina)], Eichwald [1843b, pp. 142-144]......... Do.
antiquissimus ventrosus [Obolus (Acritis)], Mickwitz [1896, pp. 213-214]... Do.

62667°—vo.t 51, pr 1—12——3

a4 CAMBRIAN BRACHIOPODA.

Present reference.

apollinis [Obolus], Billings [1872a, p. 218]............-......------------ Obolus apollinis.
IspMlhin sss (MEV Aes jos HHI|. sds soS5 ce tabesecseoscoadsees Do.
Davidson [1853, figs. 51 and 52, p. 136, and Pl. IX, figs.

PEQUO STL Melt ken LN Ma Ge 2s eae ami Do.
Davidsons les oaveley Newt oee 265) yee eee eee Obolus (Acritis) antiquissimus.
Hichwald [1829, p. 274].........-....- Seth a pee Obolus apollinis.
IBpeloygaNKl [[ISHO, ok UG |o ada s cossnobacesncancessaned 5 Do.
Bichwaldy [843 bh) 9.440] By ees eee eee eee see “Do.
Hichwald [1860, pp. 925-926]....-....------:--------- “Do.

(Ceol (MIND, 1d, ZU BAle 6 ook 6 oh edcsnsesocescessosnes Do.

Hall and Clarke [1892a, figs. 247 and 248, p. 242]... -.-.. Do.

Hall and Clarke [1892b, figs. 247 and 248, p. 558]... .-: Do.
ialWandt@lankey[ill$92.c¢%p iSO) seemeeesee eee eee eeeee Do.

Kutorga [1848, pp. 251 and 252]...........--..---.--. Do.

Matthew: 1892 spp 43—44 aes sees eee ese re eee rinses Do.
Mickwitz [1896, pp. 133=137]_-..-.---.-.--.------------ Do.

Moberg and Segerberg [1906, p. 65]...........-...----- Do.

Mornisi [i849 peoil6| see ee ince ee ecraie ee sisters eee Do.

WoeWhing (LSE, 10. AID||-o-oosccaoseseucsscascosscccesas Do.

Roemer [1876, Pl. II, figs. 7a-c] .-...-.--------------- Do.

Roemer [1885, pp. 23-24 (270-271)]...--..--.----.------ Do. ‘
Sreloveayielts [MSSM To, BIS) coos -oossosesosedecsoocscescase= Do.

de Verneuil [1845, pp. 290-292].........-.....--------- Obolus apollinis (in part), O. apollinis

ingricus (in part), Obolus (Acritis) anti-
quissimus (in part), and Obolus (Mick-
witzella) siluricus (in part).

Walcott [1898b, Pl. X XVI, figs. 3-6] -......-...--.----- Obolus apollinis.
Westergard (1909; p. 56]22- 2-2-2222 2222 sete eee ee Do.
Zittel [1880, figs. 488a-c, p. 664].........--.------------ Do.
‘ Zittel [1880, fig. 488d, p. 664]........-..--...--.------ Obolus apollinis quenstedti.
apollinis [Ungulites], Quenstedt [1885, pp. 755 and 756].......-.---.----- Obolus apollinis.
apollinis ingricus [Obolus], Mickwitz [1896, pp. 187-140] .......-..------- Obolus apollinis ingricus.
apollinis maximus [Obolus], Mickwitz [1896, pp. 140-143]...............-- Obolus apollinis maximus.
apollinis quenstedti [Obolus], Mickwitz [1896, pp. 148-145]..-.------.....- Obolus apollinis quenstedti.
appalachia [Billingsella?], Walcott [1905a, p. 231]-----.-...--.-.---------- Billingsella? appalachia.
appalachia [Dicellomus], Walcott [1905a, p. 314]..-...-.-.-.--.---------- Dicellomus appalachia.
appolinus? [Obolus], Owen [1852, p. 501] .------------.-----------+------- Dicellomus politus.
argenta [Acrotreta], Walcott [1902, pp. 580-581].....----.---.------------ Acrotreta argenta.
argenta [Nisusia (Jamesella)], Walcott [1905a, p. 252]..........-.---------- Nisusia (Jamesella) argenta.
argia [Syntrophia primordialis], Walcott [1905a, p. 293].-.......-.-.------ Syntrophia primordialis argia.
argutus [Obolus (Lingulella)], Walcott [1898b, p. 396]...-----..-----.------ Lingulella arguta.
artemis [Acrothele], Walcott [1908d, p. 82]..........--..-..-.--.---------- Acrothele artemis.
asiatica [Obolella], Walcott [1905a, p. 297]...........-.--.--------------- Obolella asiatica.
aspera [Lingulella radula], Matthew [1903, pp. 204—205]......---------.-.-- Lingulella radula.
atava [Orthis (Plectorthis?)], Walcott [1905a, pp. 259-260]..........-......- Eoorthis atava.
atava [Rafinesquina?], Schuchert [1897, p. 338].........-.--------------- Do.
atava [Strophomena], Matthew [1893b, pp. 102-103].............-.--.----- Do.
atava [Strophomena?], Moberg and Segerberg [1906, Pl. II, figs. 7, 7a-b] -. Do.
atavus [Leptobolus], Matthew [1899b, pp. 200-201].................--.--- Lingulella atava.
Matthews [19039 pps 06109] eee eeeeease-e eee eee Do.
atavus [Obolus (Lingulella)], Walcott [1902, pp. 609-610]............-..... Do.
atavus insulee [Leptobolus], Matthew [1903, pp. 110-112] -...............- Lingulella atava insule.
atavus tritavus [Leptobolus], Matthew [1903, p. 109].....-...-..--..---.-- Lingulella torrentis.
atlantica [Obolella], Burr [1900, p. 47].-..--.----..--..--...-..--..----- Obolella atlantica.
Gorham [1905, Pl. I, figs. 2a-c] ....--..--...--------- Do.
Grabaw (1900) pps 620-621] Faas 2 See eases esses eee Do.
Grabau and Shimer [1907, p. 188]....-..--...-------- Do.
Wien iovenen (UEGWCL, fos MO) secascocccadaccpeoonecccosees=c Do.
Werkeoui, MEO), To BG] coccnobessadadonssncsedseedens Do.
Welkconii leiila, jos Gib betelsecsueheeececonssoscesda5 Do.
atlantica [Obolella cf.], Delgado [1904, p. 364]..........-.....-..-.-.------ Obolella? sp. undt. a.
Atrypa? lenticularis Dalman [1828, pp. 132-133]..............-.---------- Orusia lenticularis.
Teh haeay0|[MEBY/S oh VOlpsscecssebeoeeoasscsesocecasess Do.

SYNONYMIC REFERENCES. 30

Present reference.

Atrypa lenticularis Kjerulf [1857, p. 92]..-....-..-...-.-------+---------- Orusia lenticularis.
TG erault (MEY, Toyo, UW eial B]cscdocasosancccsseesessasee Do.
JS rule [MSOs Teal SUE) Gocaaeososccooasobeaeandaonads Do.
atrypoides [Orthis lenticularis], Matthew [1892, p. 48]..--..-.------------ Orusia lenticularis atrypoides.
Matthew, [1903 ps 217i taeeeereaee eee. oe Do.
atrypoides [Orthis (Orusia) lenticularis], Walcott [1905a, p. 276].--.-----.-- Do.
attenuata [Acrotreta], Meek [1873, p. 463]........-..----.---------+-+----- Acrotreta attenuata (in part), A. attenuata
: var. (in part), and A. idahoensis (in part).
Wealleobty[i'905ass10.029 8) Baers ee eee ae Acrotreta attenuata.
attenuata [Lingula], Bornemann [1891, pp. 437-488].....-...-------------- Lingulella bornemanni.
attenuata var. [Acrotreta], Walcott [1$05a, p. 298]...--.....--.------------ Acrotreta attenuata var.?
auga [Obolus (Lingulella)], Walcott [1898b, pp. 396-397] .--...--.--------- Lingulella auga.
AtMonotretay Dall (Sian Gl: eee as-c: o hes ga eeeiee see a teeaeee see ae Obolus (Acritis). f
Hall and Clarke [1892a, pp. 243-244].................-------- Obolus (in part) and O. (Acritis) (in part).
Hall and Clarke [1892b, pp. 559-560]..--..--- ee eee Be eS Do.
Teleill ene! Clendica [MURS 1D. BAlleosccecsdoosssoose sueacwosoueces Do.
Tecinioneege, [PUSH TOO. ASA) baceousonaocscesousecaceudccuscecs Obolus (in part), O. (Acritis) (in part), and
O. (Mickwitzella) (in part).
Worry [[ISES), 779), BUGS cocoseoncconssasteeanaesoecconsanae Obolus (Acritis).
Aulonotreta antiquissima Hall and Clarke [1892a, figs. 246 and 247, p. 244]..Obolus (Acritis) antiquissimus.
Hall and Clarke [1892b, figs. 246 and 247, p. 560]... Do.
Aulonotreta polita Kutorga [1848, pp. 279-282]...........-.-----.-------- Obolus apollinis (in part), O. apollinis

ingricus (in part), and O. (Mickwitzella)
siluricus (in part).

Aulonotreta sculpta Dall [1877, p. 16]...................--..--..----.--- Obolus (Acritis) antiquissimus.
Kutorga [1848, pp. 282-283].................-....----- Do. 2
aniroray |luineu!l al eval [SGI sp. 24) eeeseee eee sees ees cee eee sees Obolus (Westonia) aurora.
TFTaTI(MSG2N pe Di| eee cle woremaen due ba oc enn Nae ee Do.
Tell (MGS, 190, WAFS bcoesosacsecsessessequadoococss Do.
Teel (PISA, top, OPO Sones oso ecudacascebcaneccen Do.
Sticlesom (GG, jo, Wi]|-consscbocccovescoccsoccacaceautces Do.
aurora [Lingulella], Grabau and Shimer [1907, p. 193]......---.-..-:------ Do.
all) (W873; pp. 244-245] 22 se sss vee he ee Seas eee Do.
Hall and Clarke [1892c, Pl. II, figs. 12 and 13] --..-.-- Do.
aurora [Obolus (Westonia)], Walcott [1901, p. 691]..-.-..-...-.-...-------- Do.
aurora var. [Lingula], Hall [1863, pp. 127-128].........-....--.-----:---- Obolus (Westonia) stoneanus.
TEL UO, (979, MOMS) pose dacocsnancoscassaccacace Do.
aurora var. [Lingulella], Hall [1878, pp. 244-245]..........-.....--.------- Do.
avia [Acrothele], Matthew [1899b, pp. 202-203]....................-......-Acrothele avia.
Martith ew: ['902b) pps. o96—398)) 5222-2 ee eee eee een ee Do.
Matthew [1903, pp. 55 and 98-99] ................------- Do.
avia-puteis [Acrothele], Matthew [1902b, p. 398].....-......-..-.--------- Acrothele avia puteis.
Marth ews [1903555 100) Beeeee see eee ene eee eee Do.
Avicula? desquamata Hall [1847, p. 292].......-----..---------+----++---- Obolella crassa.
B.
babel [Acrotreta], Barrande [1879b, Pl. XCV, figs. vir: 1-2]..-...--..----/ Acrotreta babel.
baileyi [Acrotreta], Hall and Clarke [1892a, Pl. III, figs. 28-30]..-.....--- Acrotreta baileyi.
lebeyll gua! Clendke |[IEMMe. fo. IQ |o. = 2eesecossseccocasccee 1 Do.
MlemnilaeNyy USE, TO BIW lo ood scoceoosceosceasasscoce Do.
Whyte [O02 19. HB soss4oseeoccsscoesesssusacaacac Do.
We ynVaeN? (OR. 10, Oi] ke soseconseesssocauealsscnos=soncs Do.
Walcott l02 Tp p08 582) ) eee eee ee eee Do.
baileyi? [Acrotreta], Matthew [1892, p. 43].........-.-.-.-.1...-.--.--..- Acrotreta bisecta.
baltica [Obolus (Westonia)], Walcott [1905a, p. 334]..............-.-..--- Obolus (Westonia) balticus.
barabuensis [Lepteena], Whitfield [1878, p. 60]......-...--.-.--.-..--.---- Syntrophia barabuensis.
Whitfield [1882, pp. 171-172 and 195]......-..--..-- Do.
barabuensis [Orthis], A. Winchell [1864, p. 228]................-..----.--- Do.
barabuensis [Syntrophia], Hall and Clarke [1893b, p. 216]....-..--..--..- Do.
Walcott [1905a, pp. 290-291]. ..........-----... Do.
barbata [Acrothele], Moberg and Segerberg [1906, pp. 67-68]........-..---- Acrothele ceratopygarum.

barrandei [Botsfordia?], Walcott [1908d, pp. 77-78]......-..---..---------- Botsfordia? barrandei.

36 CAMBRIAN BRACHIOPODA.

Present reference.

bavarica [Lingula], Barrande [1868a, p. 100].......-..-.-..--.-------.--- Obolus? bavaricus.
Barrande [1868b, pp. 690-691]. .........--..--...-..- Do.
bavarica [Orthis], Barrande [1868a, p. 99].......-....-....-----------.---- Eoorthis bavarica.
lsyrermanyele |[Kelo), To, GYO|s ao ccccosoasessosccessesbaces- Do.
bella [Iphidea], Billings [1872b,'pp. 477-478].......-....----.------------- Micromitra (Paterina) bella.
Billings! [BS TAs iG i] pees ner es se te cierere oleae ac yee ees Do.
Billings) [i 882 sp ale Petes essere cee cnc cee eee oe Do.
Clark and Mathews [1906, p. 252]-...........-.----------- Do.
Grabau and Shimer [1907, p. 201].........--..---.---.---- Do.
Hall and Clarke [1892a, p. 249]. ...222.2..-2...---..2.---- Micromitra (Paterina) labradorica swanton-
ensis.
Hall and Clarke [1892c, p. 98, fig. 54]..-...-.--.--------- Micromitra (Paterina) bella. The text in-

cludes both M. (P.) bella and M. (P.)
labradorica swantonensis.

Hall and Clarke [1892c, p. 98, Pl. IV, figs. 8 and 9].....-.- Micromitra (Paterina) labradorica swanton-
ensis. The text includes both M. (P.)
labradorica swantonensis and M. (P.)

bella.
Ochilert [188 7.) 012 70) Roe a eae ets eee sere cia raieeree Micromitra (Paterina) bella.
Wellkeoriit [MEIG)D, jo. WOO). --seccsotesca soos eaasoscesessccs Do.
\WWekoous (isi, yo, GO|. cs sesedescess secsnesnossoscess Do.
bella? [Iphidea], Grabau [1900, pp. 617-618]...-.....-.-..--.-----.------ Do. ;
bellapunctata [Acrothele], Walcott [1908d, pp. 82-83]. .-.-..-.--.--.--.-- Acrothele bellapunctata.
bellatula [Acrotreta], Walcott [1908d, pp. 93-94]..........-....-..--...-.- Acrotreta bellatula.
belli [Lingula], Billings [1859, pp. 431-432]._..-............-.....-.-.--- Obolus belli.
iByilUrayegss [ISB titers 70), jo) WAN cae-sesonescosasaroncsc5 Do. ‘
bellula [Acrothele], Walcott [1897b, pp. 716—717].....---..-...----------- Acrothele bellula.
bellula [Elkania], Walcott [1905a, p. 323]............-----.--.--.--..-.--.- Obolus (Fordinia) bellulus.
bellulus [Obolus (Lingulella)], Matthew [1903, p. 205]..............--..--- Lingulella bellula.
Walcott [1898b, p. 398]......-..----------- Do.
bellus [Obolus (Lingulella)], Matthew [1903, p. 204]..............-...-.-- Lingulella bella.
Walcott [1898b, pp. 397-898].......-.--.----- Do.
Walcott [1901, pp. 685-687]........-....----- Lingulella bella (in part), L. concinna (in
part), and L. lens (in part).
belti [Linnarssonia], Matley [1902, p. 145]........-.--.--.---------------- Acrotreta belti.
belti? [Linnarssonia], Matthew [1892, pp. 42-43]. ....-.-.-.-------------- (?) This species is not specifically referred

in this monograph; it does not belong
with Acrotreta belti.

belti [Linnarssonia cf.], Matthew [1903, pp. 209-210]. ..-.-.-.-.---------- Do.
belti [Obolella], Davidson [1868, pp. 310-811] .-.-.--.-.----------------- Acrotreta belti.
Davidson (1871, pp. 340-341]--.-........-._------------- Do.
belti [Obolella sagittalis], Davidson [1871, desc. of Pl. L, figs. 15-17]. ------ Do.
belti magna [Linnarssonia], Matthew [1897b, pp. 169-170]......----------- Acrotreta sagittalis magna.
bergeroni [Acrothele], Walcott [1908d, pp. 83-84].......-...-------------- Acrothele bergeroni.
bicensis [Obolus (Lingulella)], Walcott [1901, p. 688]..--.-.....----------- Botsfordia ceelata.
Bicias Walcott [LOI ppa6 1oL67Si| evan eee ae sen een eevee ye ene Bicia.
Walcott [1908e, Pl. XI, and pp. 142 and 144]._..................--- Do.
Bicia gemma Walcott [1901, pp. 678-680]..------------------------------ Bicia gemma.
Bicia whiteavesi Walcott [1901, p. 680].............---.------------------ Bicia whiteavesi.
billingsana [Lingula], Matthew [1903, p. 205]. ......--------------------- Lingulella bellula.
billingsana [Lingulella?], Schuchert [1897, p. 256]...-.-.---------------- Lingulella grandis (in part) and L. billings-
jana (in part).
Billingsella Grabau and Shimer [1907, p. 210]-..-...--------------------- Billingsella.
iHallivands Clarke) [S9 2am ps2 (o)| seem eet Do.
Halland i @lankey[iS92Ipispd89)| sass eee Do.
Hall and @larke [1892c; pp. 230-23il]------....---.--.-----2=-- Billingsella (in part) and Nisusia (in part).
Stanmore, [U/W Wel|-nss-5s2esdcssesedsoes525e55¢230550¢ Billingsella (in part), Protorthis (in part),
and Nisusia (in part).
Walcott [1905a, pp. 227-229].......-- tei dears, Sion chateaus elayatae epee Billingsella (in part) and Wimanella (in
part).
Walcott [1908e, Pl. XI, and pp. 142 and 148]..........-.-...-- Billingsella.
Billingsella alberta Schuchert [1897, p. 158]. -.-------------------------- Nisusia alberta.

Billingsella? anomala Walcott [1905a, p. 230]. ..-..---------------------- Wimanella ? anomala.

SYNONYMIC REFERENCES.

Present reference.

Billingsella? appalachia Walcott [1905a, p. 231]...........-..----.-------- Billingsella? appalachia.
Billingsella billingsi Schuchert [1897, p. 158]..---.....---- Bape hide Se Protorthis billingsi.
(Billingsella) billingsi [Protorthis], Grabau and Shimer [1907, p. 211].-..-..-. Do.
iilitinsscllil lohnes WWelkoouis [feted ba seococaocsnsseeene sansSas0¢ccecsescea Billingsella bivia.
Bilihnagella, chee Weaikeort, [MOOM, 195 G0Bl|s.0-s0s0cse0s0->2-25070ssccc5cSecase Quebecia circe.
Billingsella coloradoensis Grabau and Shimer [1907, p. 210]...-..--------- Billingsella coloradoensis.
SelamClnert, [MIN 1s WHS nccascccossscccsaessoods Do.
Walcott [1899, pp. 450-451]...........----.----- Do.
Walcott) |1905ayipps 23234) |eassaese eee e eee Do.
Billingsella dice Walcott [1905a, p. 2384).......................--..--.--- Billingsella dice.
Billingsella exporrecta Walcott [1905a, pp. 234-236]............---------- Billingsella exporrecta.
Billingsella exporrecta rugosicostata Walcott [1905a, p. 236].........---..-- Billingsella exporrecta rugosicostata.
Billingsella festinata Hall and Clarke [1892c, p. 230]...-......--.--.------ Nisusia festinata.
Billingsella harlanensis Walcott [1905a, p. 236]...........-...-.---.------ Wimanella harlanensis.
Billingsella hicksi Walcott [1905a, p. 237]....................-..-..---.-- Billingsella hicksi.
Billingsella highlandensis Walcott [1905a, pp. 237-238]...........---.---- Billingsella highlandensis.
Billingsella lindstromi Walcott [1905a, pp. 238-239].......-....-.--.------ Billingsella lindstrémi.
Billingsella major Walcott [1905a, p. 239]-.............-......---.------- Billingsella major.
\Welkoorit (MM Ostehios AO Bubs oceacsaeosdsusscossembes Do.
Billingsella marion Walcott [1908d, p. 102]......................-..-.--.--Billingsella marion.
Billingsella obscura Walcott [1905a, p. 239]........--..-..--..---.-------- Billingsella obscura.
Billingsella orientalis Hall and Clarke [1892c, p. 230]......-..-......--.---Billingsella orientalis.
Walcott [1905a, pp. 239=240].......2.-....-........- Do.
Billingsella pepina Hall and Clarke [1892a, Pl. VIII, figs. 1 and 2]....... Billingsella coloradoensis.
Halifands Clarke) | 892e% ps 230)easseeeeeee seeeeeeee ee Do.
(Billingsella) pepina [Orthis], Sardeson [1896, p. 96]...-..-.-....----...-- Do.
Billingsella plicatella Walcott [1905a, pp. 240-241]....................... Billingsella plicatella.
Billingsella pumpellyi Walcott [1905a, p. 242]...............-.2.------+--- Billingsella pumpellyi.
Billingsella quacoensis Schuchert [1897, p. 159]............---.--------- . Protorthis quacoensis.
Billingsella retroflexa Matthew [1903, pp. 148-151]..............--.---.-- Billingsella retroflexa.
Billingsella richthofeni Walcott [1905a, pp. 242-243].............-.-...---- Billingsella richthofeni.
Billingsella romingeri Walcott [1905a, pp. 243-244]..................-..--- Billingsella romingeri.
Billingsella saffordi Walcott [1905a, p. 244].............-.--.-+.---------- Wimanella saffordi.
Billingsella salemensis Walcott [1905a, p. 245]............-........-.-.-.---Billingsella salemensis.
Billingsella striata Walcott [1905a, p. 245].............-.-.---.------------ Billingsella striata.
Billingsella whitfieldi Schuchert [1897, p. 159]........-..-..-..-....------ Billingsella whitfieldi.
Walcott) [1S05aNips 246) Sao eee eee aes Do.
Billingsella (Otusia) Walcott [1905a, p. 246].................-2..---------- Otusia.
Billingsella (Otusia) sandbergi Walcott [1905a, pp. 246-247]............-- Otusia sandbergi.
billingsi [Billingsella], Schuchert [1897, p. 158]............--....-- See Protorthis billingsi.
billingsi [Orthis], Hartt [1868, pp. 644-645]..................-2.-2.2.---- Do.
Hartt [1878, pp. 644-645].............-- Ie N ORM ant Do.
Efantt [890% pps 644-645] eae. 2 seas sehen Do.
Winitineyy (MRS, 1, 48s scosessonceesosacreseadcrasoness Do.
Wealloonis |W, joo, WSUS cosceosesscnconencsoccessouac Do.
billingsi [Orthis (Protorthis)], Wysogérski [1900, p. 227]...............-.-- Do.
billingsi [Orthisina?], Matthew [1891, p. 131]...............-.....-.--.--- Do.
billingsi [Protorthis], Hall and Clarke [1892a, p. 274]............-..--..-- Do.
Hall and Clarke [1892c, pp. 219 and 232]............. Do.
Walcott [1905a, pp. 281-282]............-..--..-.---- Do.
billingsi [Protorthis (Billingsella)], Grabau and Shimer [1907, p. 211] .-.-...- Do.
billingsi [Syntrophia], Walcott [1905a, pp. 291-292]...............-......- Huenella billingsi.
Baling stag blond [i886 pp a4 06—4677) ea eee eee ene Sees aaa ae eee Elkania.
ekKioninel [MSGi Gasket ae a eee ie oe eee oes ae tae Does not equal Elkania.
Walcott [S86 epprow2en60 sandiG2|Pseese sens e== ase eee A genus of the Gastropoda.
Billingsia? ambigua Ford [1886a, p. 467]...........---...-....--.-.-.-.--- Elkania ambigua.
Billingsia desiderata Ford [1886a, pp. 466 and 467].......-...............- Elkania desiderata.
IBiulbnovgeree role, LOG! (IIIA, Ts AbMloascacsaeeseacosssenssasosccocedsassaue Elkania ida.
Billingsia pretiosa Ford [1886a, p. 467].......-.-.-.-.-.-.-.---.---.-.---- Acrothele pretiosa.
billingsiana [Lingula], Whiteaves [1878, p. 226]........................-- Lingulella billingsiana.
billingsiana [Lingula cf.], Matthew [1894, p. 93].--..-......-....--...-..- Lingulella grandis.
bisecta [Acrotreta], Matthew [190la, pp. 275-276].................-..-...-- Acrotreta bisecta.
Wleiidoeny |[UIO20. To), SM cosdeosacancsacasssosscccoosue Do.

Matthew (1903) pp: 186-18 7]22.5-2-222225-5---------- Do.

370

38 CAMBRIAN BRACHIOPODA.

Present reference.

bisecta [Acrotreta], Walcott [1902, p. 582]............-..----.-.--..-.----- Acrotreta bisecta.
Walcott [1905a, pp. 298-299]..-....-....--..--.------- Do.
bivia [Billingsella], Walcott [mew]--------.---.---.-...-..------.--------- Billingsella bivia.
blackwelderi [Obolus (Westonia)], Walcott [1905a, p. 335].....-.--..--.--- Obolus (Westonia) blackwelderi.
bohemica [Acrothele], Hall and Clarke [1892c, p. 101].-..........-.-..-.- Acrothele bohemica.
Pompeckj [1896b, pp. 509-511]....-..------------- Do.
\Welkoonns)| MAO, Os UO scone adascaacsasssecssoe Do.
bohemicus [Obolus?], Barrande [1879b, Pl. CII, figs. vir: 1-3].-..------.-- Do.
borgholmensis [Acrothele], Walcott [1998d, pp. 84-85]........--...-------- Acrothele borgholmensis.
bornemanni [Obolus (Lingulella)], Walcott [1901, pp. 687-688].......---.-- Lingulella bornemanni.
Botsfordia Walcott [1908e, Pl. XI, and pp. 142 and 145]...............--. Botsfordia.
(Botsfordia) [Obolus], Matthew [1891, p. 148]....-.-.-...--.--..---------- Do.

Matthews [S92 sip AGS esete cece acetates See sere Do.

Botsfordia? barrandei Walcott [1908d, pp. 77-78].---.----.---------------- Botsfordia? barrandei.
(Botsfordia) pulcher [Obolus], Matthew [1891, p. 148]...............-.--.- Botsfordia pulebrs

Matthew [1892, pp. 62-63]..-..--..--..----- Do.

Matthew [1902c, p. 95])..--.---.-..--------- Do.
(Botsfordia) pulchra [Obolus], Matthew [1894, pp. 90-91].................- Do.

Matthew [1895a, pp. 115-121]............-.- Do.
bottnica [Lingula], Wiman [1902, p. 51]..........-...--..--..---.-------- Obolus (Westonia) bottnicus.
bottnica [Obolus (Westonia)], Walcott [1905a, pp. 335-336].......--.--.-- Do.
Brachiopode nouy. gen. de Verneuil and Barrande eee pp. 536- ey ..--Botsfordia? barrandei.
bretonensis [Obolus], Matthew [1902c, p. 95]-- ae ..--Obolus (Palzobolus) bretonensis,
bretonensis [Paleeobolus], Matthew [1899c, p. 202]. Le ee reese Mee Se cee ait Do.

Matthew [1903, pp. 141-148]........- Bean eee Do.

broadheadi [Linnarssonella], Walcott [1902, p. 601]...---------....--.-----Linnarssonella girtyi.
(Bréggeria) [Obolus], Walcott [1902, p. 605]. - Bite ..----Obolus (Brégegeria).

Walcott [1908e, Pl. XI, endl] pp. 142 andl 144]. Peeecie Do.

(Bréggeria) salteri [Obolus], Moberg and Segerberg [1906, p. 64]......-...- Obolus (Bréggeria) salteri.
Walcott [1902, pp. 605-606].....--.......----- Do. :
(Bréggeria) salteri var.? [Obolus], Westergard [1909, p. 56]........-.-.-.--- Do.
bryograptorum [Lingula?], Moberg and Segerberg [1906, p. 63]... . .-...--Lingulella lepis.
Westergard [1909, p. 57]..-----.------------- Do.
buchi [Keyserlingia], Hall and Clarke [1892c, p. 118]........-.....-.---- Keyserlingia buchi.

Pander [1861, columns 46-48] .........--..-------- Do.
buchi [Orbicella], Hall and Clarke [1892a, p. 254]... ...-..--..---.------ Do.

Ch Ordomrerany [[lSXD, 195 ADI osceseoscocescessesesacesoecse Keyserlingia buchi (in part).
buchi [Orbicula], de Verneuil [1845, pp. 288-289]..........-.------------ Keyserlingia buchi.
buchii [Discina], Eichwald [1860, p. 914].--..---.-..--..--.----------- Helmersenia ladogensis (in part) and Key-

serlingia buchi (in part).
buttsi [Lingulella], Walcott [1908d, pp. 70-71].......-.-..--------------- Lingulella buttsi.
Cc.

celata [Lingulella], Ford [1878, pp. 127—-128]...........--.---..--------- Botsfordia ceelata.

Hall and Clarke [1892a, Pl. III, figs. 14]. .-.......-- Do.

Hall and Clarke [1892c, pp. 57 and 58]..-.-..--.---- Do.

Walkeonn |W, Oy QBle oo ossessauseseacescooeseouse= Do.

Walcott [1887, p. 199, PI.I, fig. 16].................. Do.

\Wwalkcoutn (EOE, fOs GOs scaccscossasnssobcosnbencsce Do.
exlata [Obolella], Billings [1872a, p. 218]. .....-.....--.-.-.------------ Do.
cxlata [Obolella (Orbicula)], Ford [1871, p. 33]...--.--.-.-----.-------- Do.
czlata [Orbicula], Hall [1847, p. 290]..-..-..----.----..-.-------------- Do.
calceoloides [Obolella wirrialpensis], Etheridge [1905, p. 249].....-.---.-- Obolella wirrialpensis.
ealcifera [Camarella], Billings [1863, figs. 247a-c, p. 231]........-.-..--.- Syntrophia calcifera.
ealcifera [Camerella], Billings [186la, pp. 318-320]. ..........--..--..---- Do.

Jew Dimes) |. Jo). 220] |o 5 socseescosscadcospcssosces Do.

Meek [873 (pl 4Gay aie neh bac oscmec ss eee ae Huenella abnormis.
calcifera [Syntrophia], Grabau and Shimer [1907, p. 271]... .--.--..-----Syntrophia nundina.
calcifera [Syntrophia?], Hall and Clarke [1893b, p. 218]. ..--....-...----- Syntrophia calcifera.
calcifera [Triplecia?], Hall and Clarke [1892c, p. 270].......------------ Do.
calcifera [Triplesia], Walcott [1884b, pp. 75-76]....-.-..----.-.---------- Syntrophia nundina.
Camarella? antiquata Hall and Clarke [1893b, pp. 220-221].............-- Swantonia antiquata.
Camarella antiquata Walcott [1886b, pp. 122-123]. .............--.-..--- Do.

Warkeoini, eile, jo. GIB]|s oss on Se scccocsesseseecsooes Do.

SYNONYMIC REFERENCES. 39

Present reference.

Camarella calcifera Billings [1863, figs. 247a-c, p. 231]......-.---------- Syntrophia calcifera.
Camarella minor Hall and Clarke [1898b, p. 221].........-..------------ Obolella minor.
Camarella? minor Walcott [189la, p. 614].........-..-.....---.-------- Do.
cambria [Schuchertina], Walcott [1905a, pp. 323-324]. .........-..------- Schuchertina cambria.
cambria [Syntrophia], Walcott [1908d, pp. 106-107]. .......-.-----.------- Syntrophia cambria.
Camerella antiquata Billings [1861b, pp. 10-11]. ....-....-..-.--.--.-.-- Swantonia antiquata.
Teil hinayeys) |UHUO, os QE, 5 52 a sesscceosss eee ae SEH Do.
Billings [1862e, p. 221]........ ain Be ce SN Do.
Billings [1863, fis. 290) p. 284) - 22252. -222-2---5--- Do.
Camerellacalcifera Billings [186la, pp. 318-320]. .........-..-.---------- Syntrophia calcifera.
, TShill aves) | MRT, PADI a cos accouk cedaccoecdoscubecee Do.
Meeks [W873 cp. 464] 2:-i- Saree sees aes es sae eae Huenella abnormis.
Camerella minor Walcott [1890b, pp. 36-87]. .....-..---.---------------- Obolella minor.
Camerellaspan soumands [MS6I5 py 221] fh — 2 tee ee ease ee sees eee eee Huenella texana.
campbelli [Syntrophia], Walcott [1908d, pp. 107-108]. ...........-.---.--- Syntrophia campbelli.
cancellata [Acrotreta?], Walcott [1905a, p. 299]. ....-...----.------------ Acrotreta?? cancellata.
canius [Obolus (Lingulella)], Walcott [1902, pp. 610-611]. .........-....--Lingulella cania.
carinata [Acrotreta], Moberg and Segerberg [1906, p. 66]......-..--.---.-- Acrotreta carinata.
Causea Wiman [1902, pp. 58-54)... ......--.---..02--2- 22222222222 eee Mickwitzia.
Causea formosa Wiman [1902, pp. 53-54]. .....-...-.....---.------------ Mickwitzia formosa.
cedens [Lingula], Barrande [1868a, p. 102].....-...-..---.-------------- Lingulella cedens.
Barrande [1868b, pp. 691-692]. ........-..---..-.------ Do.
celata [Schmidtia], Hall and Clarke [1892a, p. 244]......-...--.-..-.---Obolus (Schmidtia) celatus.
Hall and Clarke [1892b, p. 560].....---.-.---.---.-- Do.
Ealikandi@larke [1$92e spas] sees saeee eee eee Do.
\Volborth’ [1869) pp: 209-212]. 2222-22-22 2-2 sen) nee Do.
celatus [Obolus (Lingulella)], Walcott [1898b, Pl. XX VI, figs. 1 and 2]... Do.
celatus [Obolus (Schmidtia)], Mickwitz [1896, pp. 159-163]. ....-....---- Do
celatus orbiculatus [Obolus], Moberg and Segerberg [1906, p. 65].-...----- Do
Westergard [1909, p. 56].-.--.-.-..------.-- Do.
Watsogin |OA, 795 Glos oo dcbesncsseosecdasbe Do.
celatus orbiculatus [Obolus (Schmidtia)], Mickwitz [1896, pp. 163-165]. . -. Do.
celatus preecisus [Obolus (Schmidtia)], Mickwitz [1896, pp. 166-167] ....-. Do.
ceratopygarum [Acrothele], Moberg and Segerberg [1906, p. 67]..----.---.- Acrothele ceratopygarum.
ceratopygarum [Discina (Acrotreta?)], Broégger [1882, p. 47]......----.---- Do.
ceratopygonum [Acrothele], Walcott [1902, p. 598].........-...-.-------- Do.
chinensis [Obolus (Lingulella)], Walcott [1905a, pp. 328-329]. .......-..-- Obolus chinensis.
christianize [Orthis], Brégeer [1882, p. 48] ..-...-..---------------------- Eoorthis christianiz (in part) and E.daunus
(in part).
(Cael [MEO joo. NO enael BA), oe poscesanscsascdaccees Eoorthis daunus.
LecpereuUll |[IRSIGI5}, oy. Ak aul Blo a 5 oc esSsonescccossaqese Eoorthis christianiz.
Iounsrerela| [MOO IO. VM\soscacoscecsbdsccscaadesoass Hoorthis daunus.
Remelé:(SSilk p69] ease hee soe eer eee Do.
Remelé![Ssoeipt 6] 2 ae: ec. aeeineee acl oe oe ee ae Do.
Roemer [1885, pp. 36, 37, and 38]....-.-..-...-..-.- Do.

christianiz [Orthis (Plectorthis)], Moberg and Segerberg [1906, p. 69]. -..- Eoorthis christianiz (in part only). The
reference includes also E. daunus and E.

tullberei.
Walcott [1905a, pp. 260-261].....-...-- EKoorthis christianiz.

chromatica [Obolella], Billings [1861b, pp. 7-8]..-..-.--.-..------------- Obolella chromatica.

Tey Dimas [UGC TOs SEM |o olcoeeceasosscesc=sc000506 Do.

iBillimes) [ilS6265;p 4219) bees seca eee ee eee Do.

IB NbhergS [MNT 10s evi le oc enccmcbacconececdecascunc Do.

IBpMbhnass (SVG, ID. WAFS). soc csaasccocececacseues Do.

Ford [1881, p. 133]. ..--.-- Sia taal ni res cies re eel eet Ae Do.

JERI) sR basaaas ae aeeaeasan ce demsessosdoc Do.

ETAL S675 sO sUIO) Ss ioe cots lsieree seers elmer Do.

Halll and Clarke [1892c, p. 67]--.:--.--.---..---.-- Do.

von) Toll (11899; p. 27].-....---.-- esa Pe Sapa (?) (See p. 592.)

Walcott [1885a, pp. 115 and 117]. _................ Obolella crassa.

Welleoint [MSEC o, 1. dIaasocnscocacepesosmasaascece Obolella chromatica.

Walloon [let 10, Gills - ot noc cecesounsaccensssuae Do.

Weaillcotity [1899s er44.6) ees ese ter areata Do.

Walcott [1905a, p. 313]-------.-.---------..-....- Do.

40 CAMBRIAN BRACHIOPODA.

chuarensis [Obolus (Lingulella)], Walcott [1898b, p. 399].....-..------.---
chuarensis [Obolus (Westonia)], Walcott [1901, p. 691]....-...----...----
cingulata [Kutorgina], Beecher [1891, pp. 345-346] .......-.-..----...---
Bornemann [1891, p. 440]. ....--...-.------------
IDeRatolstor |MHGe}, Oo BIAl|= basoossas segonsscccsseeas
Davidson [1871, pp. 342-343].......-.-.--.-------
IDA Cin [EEE JO, PZ). ccesecassscesceessacseess
Frech [1897, Pl. 1A, figs. 6a—b]...--..-.---.------
Grabau and Shimer [1907, p. 209]-....-----...----
Hall and Clarke [1892a, Pl. IV, figs. 11-13].....-.--
Hall and Clarke [1892c, p. 92]............-..------
sro “Nollll |[MEGS), O AG 4U|| -522-s-22s2552555250-5-
Walcott [1886b, pp. 102-104]..............-.------

Walcott [1886b, pp. 102-104, Pl. 1X, figs. 1-f]. ..-.-

Walcott [1886b, p. 103, Pl. LX, figs. lg—h]....-...--

Walcott [189la, p. 609, Pl. LXIX, figs. 1, la-f].....

Walcott [1891la, p. 609, Pl. LXIX, figs. lg—h]......-

Walcott) [l905a) pp. 808309) 2a. = see eseeee. een ee

cingulata [Obolella], Billings [1863, p. 284, figs. 287a-b].......-..-.--..--
Billings [/863, p. 284, fig: 287¢]2 222-22. 32-.25-- =

cingulata [Obolella (Kutorgina)], Billings [1861b, pp. 8-9, figs. 8 and 10]. -
Billings [1861b, p. 8, fig. 9]..------------

Billings [1861c, p. 948, figs. 347 and 349]. .

Billings [1861c, p. 948, fig. 348]....---.--

Billings [1862e, p. 220, figs. 347 and 349]...

Billings [1862e, p. 220, fig. 348]........--

cingulata phillipsi [Kutorgina], Matley [1902, pp. 145-147]................
cingulata pusilla [Kutorgina], Gronwall [1902, pp. 40-41] ................-
Linnarsson [1876, p. 25]. ..-.---..-.-------

Matley [1902, pp. 146-147]..............----

circe [Billingsella], Walcott [1901, p. 673]. ......-...--..--.---.---------
circe [Obolella], Billings [1872a, pp. 219-220]................--..-.------
Billings [1872c, pp. 357-858]. ..-.-.......-..----..------

Walcott [1886b, p. 118, Pl. X, fig. 3].........-..--.------

Walcott [1886b, p. 118, Pl. X, fig. 8a]............-....---
Walcott [1891a, p. 611, Pl. LX XI, fig. 3]....-..--..-..---

Walcott [1891a, p. 611, Pl. LX XI, fig. 3a]...........-.---

circe? [Obolella], Walcott [1891a, fig. 62, p. 611]..............-.-.--------
circe [Quebecia], Walcott [1905a, pp. 320-321].-............-.--.---------
circularis [Acrotreta], Moberg and Segerberg [1906, pp. 65-66]. .....-...--
clarkei [Lingulella], Walcott [mew]....--.-...----.----.------------------
Clarkella Walcott [1908d, pp. 110-111]..............-.---.-------.-------
Walcott [1908e, Pl. XI, and pp. 142 and 148]...................-

clarki [Dearbornia], Walcott [1908d, pp. 78-80]..---...-.-.--.------------
claytoni [Acrotreta], Walcott [1902, p. 583]. -.- - SRS cee eee er Peete
Clitambonites planus retroflexus Schuchert [1897, p. 184]....-...-.-..-.--
Clitambonites (Gonambonites) plana retroflexa Matthew [1895b, p. 267]. - -
cceelata [Lingulella?], Matthew [1895a, p. 126] .........-.-----.-----------
colleni [Acrothele], Walcott [new] --......-..---------------.-----------
collicia [Leptobolus?], Matthew [1899b, p. 200].--....-.---.--------------
collicia [Leptobolus], Matthew [1903, pp. 112-113].-.........-.-----------
collicia [Obolus (Lingulella)], Walcott [1902, p. 610]---.....-..--.--------
collicia collis [Leptobolus], Matthew [1903, pp. 114-115]-........-.....-----
collis [Leptobolus collicia], Matthew [1903, pp. 114-115].....-..--...------
coloradoensis [Billingsella], Grabau and Shimer [1907, p. 210]....--.-.----
Stemmons [ISO7, 1. Wis)|sscnceccassseseesssce=

Walcott [1899, pp. 450-451]......-...----..---

Walcott [1905a, pp. 231-234]............-.----

Present reference.
Obolus (Westonia) chuarensis.
Do.
Kutorgina cingulata.
Kutorgina sardiniaensis.
Micromitra (Paterina) phillipsi.
Do.
Do.
Kutorgina cingulata.
Do.

Do.

Micromitra pusilla (in part), Micromitra
(Paterina) phillipsi (in part), and Kutor-
gina cingulata (in part).

Kutorgina cingulata.

Rustella edsoni.

Kutorgina cingulata.

Rustella edsoni.

Kutorgina cingulata.

Do.

Rustella edsoni.

Kutorgina cingulata.

Rustella edsoni.

Kutorgina cingulata.

Rustella edsoni.

Kutorgina cingulata.

Rustella edsoni.

Micromitra (Paterina) phillipsi.

Micromitra pusilla.

Do.
Do.

Quebecia circe.

Do.
Do.

Obolella chromatica. The text includes
Quebecia circe.

Quebecia circe.

Obolella chromatica. The text includes
Quebecia circe.

Quebecia circe.

Obolella crassa.

Quebecia circe.

Acrotreta circularis.

Lingulella clarkei.

Clarkella.

Do.

Dearbornia clarki.

Acrotreta claytoni.

Billingsella retroflexa.

Do.

Botsfordia czelata.

Acrothele colleni.

Lingulella collicia.

Do.

Do.
Billingsella coloradoensis.
Do.

SYNONYMIC REFERENCES.

coloradoensis [Orthis], Meek [1870, p. 425]
Shumard [1860, p. 627]
columbiana [Crania?], von Huene [1899a, p. 141]

4]

Present reference.
Eoorthis desmopleura.

Billingsella coloradoensis.

Philhedra columbiana.

columbiana [Crania], Matthew [1902c, pp. 108-109]...--..-..---.--.------ Do.
columbiana [Crania?], Walcott [1889c, p. 441]. .........----.------------ Do.
columbiana [Philhedra?], von Huene [1899b, pp. 216 and 298].........---- Do.
columbiana [Philhedra], Walcott [1908c, Pl. I, figs. 5 and 5a]....-....----- Do.
complexus [Obolella??], Hall and Clarke [1892c, p. 73]....-.------------ Obolus complexus.
complexus [Obolus?], Barrande [1879b, Pls. XCV, CXI, CXIII, and CLI]. Do.
complexus [Schmidtia??], Mickwitz [1896, pp. 19-20]..-..-..-------------- Do.

compta [Orthisina], Tate [1892, p. 185]
concentrica [Acrotreta], Walcott [1902, p. 583]
concinna [Lingulella], Matthew [190la, pp. 273-274]
Matthew [1903, pp. 203-204]

concinnus [Obolus (Lingulella)], Walcott [1902, pp. 608-609]
contraria [Discina], Barrande [1868a, p. 104]
Barrande [1868b, pp. 692-693]...-...---.--.-----------

Pompeckj [1896a, p. 4]

conula [Acrotreta], Walcott [1902, p. 584]
convexa [Acrotreta], Walcott [1902, p. 584]
convexa [Ungula], Pander [1830, pp. 59 and 163]
convexa [Ungula plana or], Pander [1830, p. 163]
convexus [Obolus (Lingulella) winona], Walcott [1901, p. 691]
coriace [Acrothele], Brogger [1878, p. 76]
coriacea [Acrothele], Grénwall [1902, p. 40]
Linnarsson [1876, pp. 21-23]

corrugata [Lingula?], Moberg and Segerberg [1906, p. 63]
Westergard [1909, p. 57]

corrugata [Orthis (Finkelnburgia) osceola], Walcott [1905a, p. 280]
costata [Acrothele matthewi], Matthew [1895a, p. 128].......-..--...---.-
Matthew [1902b, p. 399].-.....--.--.-.-------

Matthew [1903, p. 104]......-....--.--...----

Crania Eichwald [1829, p. 273]
Crania? columbiana von Huene [1899a, p. 141]
Crania columbiana Matthew [1902c, pp. 108-109]
Crania? columbiana Walcott [1889c, p. 441]
Crania sulcata Hichwald [1829, p. 274]
Crania unguiculata Eichwald [1829, p. 274]
Craniella?? sp. Walcott [1905b, pp. 4 and 6]
crassa [Acrothyra proavia], Matthew [1902b, pp. 389-390]
: Matthew [1903, p. 94]
crassa [Dicellomus], Hall [1873, p. 246]
crassa [Obolella], Billings [1872a, p. 218]
Billings [1872c, p. 356]

Bornemann [1891, pp. 439-440]

Ford [1878, p. 128]

Ford [1881, pp. 131-133]

Ford [1886a, fig. 2, p. 466]

Gorham [1905, Pl. I, figs. la-f]

Grabau and Shimer [1907, pp. 188-189]

Hall and Clarke [1892a, Pl. III, figs. 5-7]

Hall and Clarke [1892c, p. 70]

Shaler and Foerste [1888, p. 27]

Walcott [1885b, p. 21]

Walcott [1886b, p. 114]

Welleonns (ME@iln, jos GIP] Loscsosoccasnessoccossacsasdagued

Walcott [1905a, p. 321]

crassa? [Obolella], Grabau [1900, pp. 619-620]
crassa [Obolella (Orbicula?)], Ford [1871, p. 33]
erassa [Orbicula?], Hall [1847, p. 290]
crassa elongata [Obolella], Walcott [new]
crassus [Obolus (Schmidtia)], Mickwitz [1896, pp. 187-193]
crassus angulatus [Obolus (Schmidtia)], Mickwitz [1896, pp. 193-194]

Nisusia compta.
Acrotreta concentrica.
Lingulella concinna.
Do.
Do.
Orbiculoidea contraria.
Do.
Do.
Acrotreta conula.
Acrotreta convexa.
Obolus apollinis quenstedti.
Obolus apollinis.
Lingulella winona convexa.
Acrothele coriacea.
Do.
Do.
Lingulella lepis.
Do.
Finkelnburgia osceola corrugata.

-Acrothele prima costata.

Do.
Do.
Siphonotreta (in part).
Philhedra columbiana.
Do.
Do.
Siphonotreta unguiculata.
Do.
Discinopsis? sulcatus.
Acrothyra proavia.
Do.
Obolella crassa.
Do.
Do.
Obolus? zoppi.
Obolella crassa.
Do.
Do.
Obolella atlantica.
Obolella crassa.
Do.
Do.
Obolella atlantica.
Obolella crassa.
Do.
Do.
Do.
Do.
Do.
Do.
Obolella crassa elongata.
Obolus (Schmidtia) crassus.

42 CAMBRIAN BRACHIOPODA.

_crenistria [Iphidea], Walcott [1897b, p. 718].....---.---.----------
cuneata [Lingulella?], Matthew [1894, pp. 92-93]..........-..---.--
cuneata [Lingulobolus affinis], Matthew [1895b, p. 262].....-...---..-----
cuneolus [Lingulepis], Schuchert [1897, p. 259]. .......-..---------
Whitfield [1877, pp. 8-9]..--.-..----.-------------

(wiliiasPeliel IBS), fo. ST saeecaaece nce sueeee «

cuneolus [Obolus (Lingulella)], Walcott [1899, p. 443].-.....-.------
(Chama, Walloouts (OOS, 70, BIO co scoscsscosescodsasnecsonecsceesss
Walcott [1908e, Pl. XI and pp. 142 and 148].............--
Curticia elegantula Walcott [1905a, pp. 319-320]. ....-.--- See
curvata [Acrotreta], Walcott [1902, p. 584]..............--..-------
cyane [Glossina], Schuchert [1897, p. 224].................---------
cyane [Lingula], Billings [1865a, p. 216]..........-..--..----------

dakotensis [Lingula], Meek and Hayden [1865, p. 3].......-.--.----

Whitfield [1880, pp. 337-338].........-.-.----
Dalmanella melita Schuchert [1897, p. 202]...............-...-..-
damesi [Obolus (Lingulella)], Walcott [1905a, p. 329]..........-.-.--

L)

dartoni [Obolus (Westonia)], Walcott [1908d, p. 67]..-..-..---.------
daunus [Orthis (Plectorthis)], Moberg and Segerberg [1906, p. 69]
Walcott [1905a, p. 261] .-.....-..--.--

Davidsonella Munier-Chalmas [1880].......---...-----------------
Waagen [1885a, pp. 762-764].............-..---------
Davidsonella linguloides Waagen [1885a, pp. 764-766].-....-..--.--
Davidsonella squama Waagen [1885a, pp. 766-767]........-...--..--

davidsoni [Lingula], Barrande [1879b, Pl. CIV, figs. vi: 1-4]

davisi [Lingula], McCoy [1851b, pp. 405-406]......-.......--..--..-
MeCoy [S854 pi252] 5. -ese ess eecscer ete se eenee

davisi [Lingula cf.], Schmidt [1881], p. 17, fig. 5]....-......---.---.-
davisi [Lingulella], Davidson [1868, pp. 304 and 306]..........--.--
Hall and Clarke [1892a, p. 232]..........--..--

Hall and Clarke [1892b, p. 548]. .-....-....-.--

Hall and Clarke [1892c, pp. 56 and 57]. ..--...--

Wikerale [IRSA Toyo), WUKG=Aey/| po ceaeeuacossssoocases-

Salter [1866b, pp. 333-334]. ..-.-.-------------

davisii [Lingulella], Davidson [1866, pp. 56 and 57].....----.--.-.-.
Teteiil (ik TAL, SOUL, te, ZY) osecsscosccsooees

Roemer [1876, Pl. II, figs. 5a-c] ...-...-..----

Salter (1867, pp. 44 and 52]........-.....-...--

Salter and Etheridge [1881, pp. 537-538]

Matthew [1886, pp. 33-34, Pl. V, fig. 9d]

DearhormanWalecontn 908d ai pI (S) pase eeeeeeee eee eee eee eee
Walcott [1908e, Pl. XI, and pp. 142 and 146].................

Dearbornia clarki Walcott [1908d, pp. 78-80]........-.---.-------
decipiens [Acrothele], Walcott [1897b, p. 716]. ...-..--..--..------
decipiens [Obolus meconnelli], Walcott [new] -.-.--..--.---------
definita [Acrotreta], Walcott [1902, pp. 584-585]. .............-..--
Delgadella Walcott [1908e, Pl. XI, and pp. 142 and 144]...............
delgadoi [Lingulella], Walcott [new].-.....-..--...--.---.-.---- aa
depressa [Acrotreta], Walcott [1908c, p. 245]................-------
depressa [Acrotreta gemma], Matthew [1902c, p. 109].............-
Walcott [1889c, pp. 441-442]..........-

davisii [Lingulella cf.], Kayser [1897, p. 280]. .......-..-.---------
Matthew [1902b, pp. 407-408]. ....-..------

Matthew [1903, p. 203]....-.----------------

davisii [Obolus (Lingulella)], Walcott [1898b, pp. 394 and 395]
dawsoni [Lingula?], Matthew MS. [1884]. .....-......-.--..-.------
Walloon GEV, io, WHE osossodescsesoadoceesscc

dawsoni [Lingulella], Hall and Clarke [1892c, p. 58]......--.-.,----
Matthew [1886, pp. 33-34, Pl. V, figs. 9, 9a-c]

Present reference.
Micromitra (Paterina) crenistria.

Se Saud Lingulella grandis.

-Obolus (Lingulobolus) affinis.
seoade Lingulella perattenuata (in part).
. Lingulella cuneola.

Do.

Do.
Curticia.

Do.
Curticia elegantula.
Acrotreta curvata.
Obolus cyane.

Do.

Lingulella (Lingulepis) acuminata.
Do.
Variety of Eoorthis desmopleura.
Obolus damesi. (See Lingulella damesi,
p. 489.)
Obolus:(Westonia) dartoni.
EKoorthis daunus.
Do.
Davidsonella, not Neobolus.
Neobolus.
Neobolus warthi.
Do.
Lingulella davidsoni.
Lingulella davisi.
Do.
Obolus (Mickwitzella) siluricus.
Lingulella davisi.
Do.
Do.
Do.
Do.
Do.

ceva Do.

Do.
Do.
Do.
Do.
Do.
Do.
Do.
Do.

La asta Lingulella ferruginea.

Do.
Do.
Lingulella martinensis. The text includes
L. ferruginea.

Raeeeeens Lingulella ferruginea. The text includes

L. martinensis.
Dearbornia.
Do.

suse Dearbornia clarki.

Acrothele decipiens.

.-Obolus meconnelli decipiens.

Acrotreta definita.

- Delgadella.

Leelee Lingulella delgadoi.

Aelia Acrotreta=depressa.

shoes Do. ‘

Do.

SYNONYMIC REFERENCES. 43

Present reference.

descendens [Acrotreta ophirensis], Walcott [1908d, p. 95]. -...-..-.-..---.-Acrotreta ophirensis descendens.
desiderata [Billingsia], Ford [1886a, pp. 466 and 467].......-..----------- Elkania desiderata.
desiderata [Elkania], Ford [1886b, p. 325]..............--..------------- Do.
Hall and Clarke [1892a, Pl. III, figs. 13 and 14]...--. Do.
Hall and Clarke [1892c, pp. 76 and 77]..---.---.---- Do.
desiderata [Obolella], Billings [1862d, pp. 69-70]...........--.--..------- Do.
IDeniGOm |[WAKS, O, BOs ocosssasscecssdcesceqn0nes Do.
desiderata [Obolella?], Walcott [1886b, p. 111]..............-.----.------ Do.
desideratus [Obolus (Lingulella)], Walcott [1898b, pp. 399-400] .......--.- Lingulella desiderata.
Walcott [1899, pp. 445-446, Pl. LX,
1G: SO] eRe ate oe a as a Do.
Walcott [1899, pp. 445-446, Pl. LX,
figs ai] ot Nee sean sieiteee ose aero = Obolus rotundatus.
desmopleura [Orthis], Meek [1872, p. 295]. ..-.....-.----------------+--- Eoorthis desmopleura.
desmopleura [Orthis (Plectorthis)], Walcott [1905a, p. 261]......-..-.--.-- Do.
desmopleura nympha [Orthis (Plectorthis)], Walcott [1905a, p. 262]...-..-. Hoorthis desmopleura nympha.
desquamata [Avicula?], Hall [1847, p. 292]..........-.--.--------------- Obolella crassa.
desquamata [Obolella], Billings [1872a, p. 218]. .-.-..-...--.---.--------- Do.
IBlbiMNeS |[TEVAC, jo, SHG|-s50cceesccccsdeccsecase Do.
diablo [Orthis (Plectorthis)], Walcott [1905a, p. 262]..........--..------- EKoorthis? diablo.
dice [Billingsella], Walcott [1905a, p. 234]..........--...--.------------- Billingsella dice.
Dicellomus Grabau and Shimer [1907, p. 189]. ...--.----.--.--.--------- Dicellomus.
La US i8s Dit ZA Glee oteoas sa osters Nac toeres oh ese aioe lewis Do.
Hall and Clarke [1892a, pp. 240-241]...............-..-.--.-- Do.
Hall and Clarke [1892c, pp. 66-73]...-....----...------------ Do.
Welleogs IEE) oad Sao eee can ostnc sono boncc ube Sae Seco enaes Do.
Wealleoiii |(MOtr, joy, BIB RBIE |. 2 coccanonodocoesonecoeaccaouece Do.
Wal :ott [1908e, Pl. XI, and pp. 142 and 144]................. Do.
Dicellomus appalachia Walcott [1905a, p. 314]...............-..--.------ Dicellomus appalachia.
Dicellomus|crassa Halll [8 73) ip. 2465. ---2----2-.24-445- 52 esse ee Obolella crassa.
Dicellomus nanus Walcott [1899, p. 447]. ....-..-...--.--.--------+------ Lingulella desiderata (in part) and Dicello-
mus nanus (in part).
Walleout [Ose jaa, SING sesccsaconsonccscsaasaose Dicellomus nanus.
Dicellomus parvus Walcott [1905a, pp. 315-316].............-..---.---.-- Dicellomus parvus.
Dicellomus pectenoides Walcott [1901, p. 673].-.........-.--------------- Dicellomus pectenoides.
Wealleoiit MOOSE, 1. BIG) -nceaceoscsaccecscacscacesc Do.
Dicellommsfpolitay relly [NS7355 pa24.6] Seaeee eee eee ee aeee eee seer eee Dicellomus politus.
Dicellomus politus Grabau and Shimer [1907, pp. 189-190]. ....-.--....-- Do.
Walcott [1899, pp. 443 and 446]. .....-...--..--..---- Do.
Walcott [1905a, pp. 313 and 316-318]. ..........-....- Do.
Dicellomus prolificus Walcott [1908d, p. 77] .-...--...--.------------------- Dicellomus prolificus.
Dicellomus sp. undt. Walcott [1905a, p.,319].......-.--.----------------- Dicellomus sp. undt.
dichotoma [Acrothele?], Walcott [1884b, pp. 14-15]...............-...---- Acrothele dichotoma.
dichotoma [Acrotreta], Hall and Clarke [1892c, pp. 100 and 103]-....-..... Do.
Walken | TUSSI, TO. WOM: oe ssacoccaccsescascareess Do.
Discina buchii Hichwald [1860, p. 914]..........-...-..---.---..------.- Helmersenia ladogensis (in part) and Key-
serlingia buchi (in part).
Discina contraria Barrande [1868a, p. 104]...-..........-...-...---.-- . -Orbiculoidea contraria.
BeraenaGle |NMas10, 1919), GEE) |. «oo sesscscaocceacocosece Do.
Pompeckyi[896ar py Alesse cases ceasee cies Do.
Diseimaplabiosa salten|lS66aip. 280 assesses e ses see see ae eee eee eee ee Acrotreta sagittalis.
Discina microscopica Shumard [1861, p. 221].........-..--..-------.----- Acrotreta microscopica.
Discina pileolus Davidson [1868, pp. 312-313]...........-.....--.--------- Orbiculoidea pileolus.
Dawidsony [Sia apess4 | -aeesect asec ese ee Sea eee ee Do.
(Hicks MS;)) Salter [866a, p: 285]/2-22--2-5----4--------- Do.
Discina pileolus? Hicks [1871, Pl. XV, figs. 12 and 12a]...........-......- Stenotheca pileolus, a gastropod.
Discina varians Barrande [1868a, pp. 103-104]................-..--.----.-- Orbiculoidea varians.
IdpreemmnGle [MGs Ws GA edeececsas ss conesdaccosusssescse Do.
Rompecky,[S96ay py 4a cee eee eerie ae eee Do.
IDMgerin, Ro). Wkowre)| EIR}, jp Ollecaheae- - cepsseccesocossasecesoessnesascen Acrothele bergeroni.
Migielsfls94as ps LOG ice tssce scans seaeaeense eis eee oe Do.
Miguelt[l894b yp y1O) soi bee sctcqueeciecei en een ees a: Do.

WY opel | USL 104 0) eee eee ceberes selec ston eadc mda mete oe Dor

44 CAMBRIAN BRACHIOPODA.

Present reference.

Discina? sp. Kjerulf [1873, p. 83, figs. 12 and 18].........--.-..--.-------- Obolella (Glyptias) favosa?.
Discina (Acrotreta?) ceratopygarum Brogger [1882, p. 47]..-..----------- Acrothele ceratopygarum.
Discina (Orbicula) primzeva de Verneuil and Barrande [1860, p. 532] ....Acrothele primeva.
Discinolepis Hall and Clarke [1892a, p. 247]................-.------------ Discinolepis.
Taki eyaxel Oleyilice: |[IEI20), jo), (18) |cosccseone scasconseesssccsece Do.
Hall and Clarke [l892c) pp. 90]e22222 2255225. +2522 sseee eae: Do.
Waagent |iS8oanppa49— 750) Saeeee see enee ne eee ne esses Do.
Walcott [1908e, Pl. XI, and pp. 142 and 146]................ Do.
Discinolepis granulata Hall and Clarke [1892a, p. 247].........---.------- Discinolepis granulata.
Hall and Clarke [1892b, p. 563]........------------ Do. i
Hall and Clarke [1892c, p. 90]......-...-.--...-..- Do.
Waagen [1885a, pp. 750-751]. --------2.-------22 22: Do.
Waagen [1891, Pl. II, figs. 15 and 16]............--- Do.
Discinopsis Hall and Clarke [1892a, pp. 250-251]...............--.-.----- Discinopsis.
Hall and Clarke [1892b, pp. 566-567]..........-.......-..---- Do.
Hall and Clarke [1892c, pp. 105-106]. ..............-.-.--.---- Do.
Walcott [1908e, Pl. XI, and pp. 142 and 146].........-.-.-...- Do.
Discinopsis gulielmi Hall and Clarke [1892a, Pl. III, figs. 20 and 21]....... Discinopsis gulielmi.
Hall and Clarke [1892c, p. 105].....----.-.--..----- Do.
Discinopsis sulcatus Walcott [1906, pp. 568-569]............-........-..-..--Discinopsis? sulcatus.
discoida [Obolella], Hall and Whitfield [1877, p. 205]...........-..-...--.- Obolus discoideus.
discoidea [Obolella?], Hall and Clarke [1892c, p. 69] ..-...-...-.---------- Do.
discoidea [Obolella], Walcott [1884b, p.14]..............--.---.----.----- Do.
discoidea [Obolella?], Walcott [1886b, p. 111].............--..--..-------- Do.
discoideus [Obolus (Lingulella)], Walcott [1901, p. 673]..........-...--..-- Do.
discus [Obolus], Matthew [1902c, p. 94]....-....-..--.---.---.------------ Lingulella triparilis.
discus [Obolus (Eoobolus)], Matthew [1903, pp. 188-139]...........-.-..---- Do.
dolata [Lingula], Sardeson [1896, p. 95]-. -..-..-..-..-.--.----..----.---- Obolus dolatus.
doris [Orthis (Plectorthis)], Walcott [1905a, pp. 262-263].......--...--..--- Eoorthis doris.
dougaldensis [Protorthis (Loperia)], Walcott [1905a, pp. 287-288] ..........-- Protorthis (Loperia) dugaldensis.
dubia [Siphonotreta?], Walcott [new]...........-..--..------------------ Siphonotreta dubia.
dubius [Obolus (Lingulella)], Walcott [1898b, p. 401]....-.-...-...-...---- Lingulella dubia.
edsoni [Rustella], Walcott [1905a, pp. 311-312]............-...-...---.--- Rustella edsoni.
eggegrundensis [Acrotreta], Walcott [1905a, pp. 299-300]...........-..-.--- Acrotreta eggegrundensis.
Wanner ([NO2, [D- BSbacccascsoesesecccsoossonus Do.
eichwaldi [Obolus], Mickwitz [1896, pp. 154-155] ...............-....-..-- Obolus eichwaldi.
elegans [Obolus], Mickwitz [1896, pp. 157-158].-............-.-----.------ Obolus elegans.
elegantula [Curticia], Walcott [1905a, pp. 319-320]........--.-.......-..--- Curticia elegantula.
elegantula [Strophomena (Eostrophomena)], Walcott [1905a, pp. 256-257] . Eostrophomena elegantula.
Taya, oyael |MATHO, 10, BWlLeososoe ose ene sseoseeaensosaseseesecsoresosee Elkania.
Tseybl gyno! Clade |[Me eA, jo, Mall -Secoosenodosonsbecsscscconssece Do.
Hall and Clarke [1892b, p. 557].--..-.--.---.-.----------------=- Do.
Halivand@lankel|[1S92eeppe/b—(sllseeeeeeeseee eee cee ee eeee Do.
Walloon MOE, (ios BUBB) |.5e55 cc sd bose ossabacndbacsasecaesaes Elkania (in part) and Obolus (Fordinia),
(in part).
Walcott [1908e, Pl. XI, and pp. 142 and 144]...................- Elkania.
Elkania ambigua Ford [1886b, p. 325]......-.....-.---.-----------.----- Elkania ambigua.
HallFand’@larket[il$92c%ip/S) sess sseeeeeee ee eeeeee eee Do.
Elkania bellula Walcott [1905a, p. 323]........-...--..---.--------------- Obolus (Fordinia) bellulus.
Elkania desiderata Ford [1886b, p. 325].....-..-..-.-.--..----.----------- Elkania desiderata.
Hall and Clarke [1892a, Pl. III, figs. 13 and 14]....-.. Do.
Hall and Clarke [1892c, pp. 76 and 77].-..--.-.------- Do.
Dilan, rks, Towel |MANVO, fo. Bills. seed soosds case cncssconcsoascuasecsae Elkania ida.
Elkania pretiosa Ford [1886b, p. 325]...........---..---.----------------- Acrothele pretiosa.
ella [Lingulella], Hall and Clarke [1892c, p. 58, figs. 19 and 21]...........-. Obolus (Westonia) ella. The text includes
also specimens representing Lingulella
dubia.
Hall and Clarke [1892c, p. 58, fig. 20]. .....-...- hee eeee Lingulella dubia.
Packs (1906) 94295] |saaccons ce Sane eee Snes saa eeeee Obolus (Westonia) ella.
Walcott [1886b, pp. 97-98, Pl. VII, fig. 2; Pl. VIII, figs. 4,
Aer Adel Dodo etic seks han ae aon sees Obolus (Westonia) ella. The text includes

also specimens representing Lingulella
dubia.

SYNONYMIC REFERENCES. 45

Present reference.
ella [Lingulella], Walcott [1886b, pp. 97-98, Pl. VIII, figs. 4b and 4c] ....-. Lingulella dubia. The text includes
Obolus (Westonia) ella.
Walcott [1891a, p. 607, Pl. LX VII, figs. 2, 2a—b, and 2e]. -Obolus (Westonia) ella. The text includes
also specimens representing Lingulella

dubia.
Walcott [1891a, p. 607, Pl. LXVII, figs. 2e-d]........-.- Lingulella dubia. The text includes Obo-
lus (Westonia) ella.
ella [Lingulella (Westonia)], Grabau and Shimer [1907, p. 193].-...-..-.-.- Obolus (Westonia) ella.
ella [Lingulepis], Hall and Whitfield [1877, p. 232].....-..-...---.-.--.--- Do.
Walcott; [897s p-/404]en ater ees an eee ee eae Do.
ella [Obolus], Matthew [1902c, pp. 96 and 110]..-.....-.....--..--------- Do.
ella [Obolus (Lingulella)], Walcott [1898b, Pl. XXVIII, figs. 5-8]. ......--- Do.
ella [Obolus (Westonia)], Walcott [1901, p. 691].-...--..--.-------------- Do.
ella onaquiensis [Obolus (Westonia) |, Walcott [1908d, pp. 67-68] -...-...-- Obolus (Westonia) ella onaquiensis.
ellipticus [Obolus (Schmidtia) obtusus], Mickwitz [1896, pp. 177-178]... .Obolus (Schmidtia) obtusus.
ellsi [Obolus (Lingulella)], Walcott [1898b, p. 402] .........----..-------- Lingulella ellsi.
- elongata [Obolella crassa], Walcott [mew]...........-.-------+-----+----- Obolella crassa elongata.
elongatus [Obolus (Westonia)], Walcott [1908d, p. 68].........-.----------- Obolus (Westonia) elongatus.
emmonsi [Acrotreta], Walcott [1905a, p. 300].....---.---.---------------- Acrotreta emmonsi.
_endlichi [Micromitra sculptilis], Walcott [1908d, p. 56] .....-.....-..------ Micromitra sculptilis endlichi.
Booloolns Wertdaeny |IOOHe., Jos Q/|soodsossocesobocencoseccaccoosoeuanesacs Lingulella.
(Eoobolus) [Obolus], Matthew [1903, pp. 185-136].................------- Obolus (in part) and Lingulella (in part).
(Eoobolus) discus [Obolus], Matthew [1908, pp. 138-139]............-.---- Lingulella triparilis.
(Eoobolus) triparilis [Obolus], Matthew [1903, pp. 136-137]. .....--.---.-- Do.
Koorthis Walcott [1908d, pp. 102-104].................-..--..---+--+------ Koorthis.
Walcott [1908e, Pl. XI, and pp. 142 and 148] ................... Do.
Eoorthis newberryi Walcott [1908d, p. 105].......-...-.-......---------- Eoorthis newberryi.
Hoorthis thyone Walcott [1908d, pp. 105-106].................- Haden saeS Koorthis thyone.
Hoorthis)zeno Walcott [1908ds p: l06]22..22222.--2-.-...2----.-----+----- Eoorthis zeno.
Eostrophomena Walcott [1908e, Pl. XI, and pp. 142 and 148]............. Eostrophomena.
(Eostrophomena) [Strophomena], Walcott [1905a, p. 256].......-......--- Do.

(Hostrophomena) elegantula [Strophomena], Walcott [1905a, pp. 256-257]. . Eostrophomena elegantula.
(Eostrophomena) walcotti [Strophomena], Moberg and Segerberg [1906,

Ds Zl) cocassosssoccsoesucesuopeuoauauodsubasboSusedsososoobcaobees Z Do.
erecta [Nisusia (Jamesella)], Walcott [1905a, p. 253].......-....------------ Nisusia (Jamesella) erecta.
eros [Obolus (Lingulepis)], Walcott [1905a, p. 333].............-.--------- Lingulella (Lingulepis) eros.
eryx [Acrothele matthewi], Walcott [1905b, p. 11].......-...-..-...--..-- Acrothele matthewi eryx.
escasoni [Lingulella(?)], Matthew [190la, pp. 270-273]...........--..-..-- Obolus (Westonia) escasoni.
escasoni [Obolus (Westonia)], Walcott [1901, p. 691].....--.--..---.---.--- Do.
escasoni [Westonia], Matthew [1903, pp. 206-209]...........-.-.--..------- Do.
esthonia [Schizambon ?], Walcott [new].....-...------.---+-------------- Schizambon ? esthonia.
etheridgei [Huenella], Walcott [1908d, pp. 109-110]................-.....- Huenella etheridgei.
etheridgei [Platyceras], Tate [1892, p. 184].......-.........-....------.--- Micromitra (Paterina) etheridge.
euglyphus [Obolus (Lingulella)], Walcott [1898b, pp. 402-403]. .........-. Obolus (Westonia) euglyphus.
euglyphus [Obolus (Westonia)], Walcott [1901, p. 691]...-...--.---..-..--- Do.
(Euobolus) [Obolus], Mickwitz [1896, pp. 129 and 133]...................- Lingulella (in part) and Obolus (in part).
eurekensis [Orthis?], Schuchert [1897, p. 286].......-..--..-----.--------- Orusia ? eurekensis.
eurekensis [Orthis], Walcott [1884b, pp. 22-23]...-........---...--------- Do.
eurekensis [Orthis (Orusia?)], Walcott [1905a, p. 277]..........-.--.------ Do.
eurekensis [Protorthis?], Hall and Clarke [1892c, p. 232]............-.-..-- Do.
excelsis [Trematobolus], Walcott [1908d, pp. 80-81]. .....................- Trematobolus excelsis.
exigua [Lingulepis starri], Matthew [1903, pp. 197-198]...................-Lingulella (Lingulepis) exigua.
exporecta [Orthis], Linnarsson [1876, pp. 12-13]..................--.-..-- Do.
exporrecta [Billingsella], Walcott [1905a, pp. 234-236]. . -..----------BDillingsella exporrecta.
exporrecta [Orthis], Kayser [1883, p. 35]......-....-.-...---.------------ Do.

Wellleming [MEO Os GBlocscasaccsosuscooscescceocage Do.

exporrecta rugosicostata [Billingsella], Walcott [1905a, p. 236].........-.... Billingsella exporrecta rueosicostata:
extenuatus [Obolus (Schmidtia) obtusus], Mickwitz ea pp. 178-179]... -Obolus (Schmidtia) obtusus.
exungui [Lineula aff.], Giirich [1896, p. 214]--. -ee-++----------------JAngulella siemiradzkii.
exunguis [Lingula cf.], Gtirich [1892, p. 69]...........--...............- Do.

Siemiradzki [1886, p. 672]...........-.-.-.--...-. Do.

‘ae

46 CAMBRIAN BRACHIOPODA.

F.
Present reference
favosa [Lingula(?)], Linnarsson [1869a, pp. 356-357].........-.-.--.------- Obolella (Glyptias) favosa.
Linnarsson [1869b, p. 406]......--........------------ Do.
favosa [Lingulella(?) cf. Lingula], Matthew [1888, pp. 28-29]...--.-..---.-- Botsfordia pulchra.
favosa [Obolella (Glyptias)], Walcott [1901, pp. 675-676]........-----.-.-.-Obolella (Glyptias) favosa.
feistmanteli [Lingula], Barrande [1879b, Pls. CVI and CX]....-....--.--- Obolus feistmanteli.
ferruginea [Lingulella], Davidson [1868, pp. 306-307]..-------------------- Lingulella ferruginea.
De alsom |S7/il, 710), BHESB encosesasopaecse-s55e- Do.
Davidson [1883, Pl. XVII, ie oo SA eee ea Do.
Delgado [1904, pp. 368-369] .-.--.....--....-.-----Lingulella delgadoi.
Matthew [1903, p. 108]-- i ...-------Lingulella ferruginea.
Salter [Salter and Hicks, 1867, P. 340]. anise Seeeesee Do.
Salter and Etheridge [1881, OSS Saeeese se tes eee Do.
ferruginea [Lingulella cf.], Kayser [1897, p. 280] -....-..-..-.--.---------- Do.
ferruginea ovalis [Lingulella], Davidson [1868, p. 307].-.....---..-....--- Do.
Hicks [Salter and Hicks, 1867, p. 341]...-... Do.
festinata [Billingsella], Hall and Clarke [1892c, p. 230]..............------ Nisusia festinata.
festinata [Nisusia], Grabau and Shimer [1907, p. 211]..........-...-...--- Do.
Walcott [1905a, pp. 249-251].......-.....1..-.-.-..--- Do.
festinata [Orthisina], Billings [1861b, p. 10]........--.......-..----.------ Do.
Teil bivayeys) |PMXGUC, fo), PD oa seocoseosescesesuersses0e5ec Do.
IMU AGA), jo), WO||p-sstoseseoaceaossescesacsees Do.
TeRblbbenversy |MIHAS, jo, Alls Jso-essscecaseocesecoseasee Do.
Billings [1863, p. 284, figs. 289a-c] ...-....--.-...--- Do.
Walcott [S86 bs pps 20 S12 Ree eae ne eee Do.
Wiellewir, (eile, 79). GUS. csecceseceosesseaasesceesess Do.
festinata transversa [Nisusia], Walcott [1905a, p. 251].........-..-.------- Nisusia festinata transversa.
finkelnburgi [Orthis (Finkelnburgia)], Walcott [1905a, pp. 278-279]...-.--- Finkelnburgia finkelnburgi.
Finkelnburgia Walcott [1908e, Pl. XI, and pp. 142 and 148]............... Finkelnburgia.
(Finkelnburgia) [Orthis], Walcott [1905a, pp. 277—278]..-.-.-.------------ Do.
(Finkelnburgia) finkelnburgi [Orthis], Walcott [1905a, pp. 278-279]. --..-- Finkelnburgia finkelnburgi.
(Finkelnburgia) osceola [Orthis], Walcott [1905a, p. 279].....-.------------ Finkelnburgia osceola.
(Finkelnburgia) osceola corrugata [Orthis], Walcott [1905a, p. 280]. -.-.-.-- Finkelnburgia osceola corrugata
finlandensis [Obolus (Westonia)], Walcott [1902, pp. 611-612]........----- Obolus (Westonia) finlandensis.
flumenis [Leptobolus], Matthew [1903, pp. 189-190]. .---- pad sie Dawe aa ele Lingulella flumenis.
(Fordinia) [Obolus], Walcott [1908d, pp. 64-65].....-.-.-.--------------- Obolus (Fordinia).
Walcott [1908e, Pl. XI, and pp. 142 and 144]......... Do.
(Fordinia) gilberti [Obolus], Walcott [1908d, p. 65].-.-....--------------- Obolus (Fordinia) gilberti.
(Fordinia) perfectus [Obolus], Walcott Ce. pp. cee _..--------------Obolus (Fordinia) perfectus.
formosa [Causea], Wiman [1902, pp. 53-54]... eee ere ickwitiziagtonmosas
fragilis [Obolus (Lingulella)], Walcott [1898b, 7 p- 404]. Hee S SAE a Nee eee Obolus fragilis.
franklinensis [Obolus (Lingulella)], Walcott [1898b, pp. 404-405]_---.....-- Lingulella franklinensis.
raucelatert |Usiovequilesley, Ieverollbyetm |[Is!), 79), /|b----se2-ss2s0csce5ce sacocsoeoeeo Lingulella fuchsi.
fuchsi [Obolus (Lingulella)], Walcott [1905a, p. 332]..-.-------.----------- Do. |
G.
eamagei [Acrothele], Grabau [1900, pp. 615-617]. ......-.-.-------------- Acrothele gamagei.
Grabau and Shimer [1907, p. 200]......--..----.---- Do.
Shimer [1907, pp. 176 and 177]...-....-------------- Do.
gamagei [Obolella], Hobbs [1899, pp. 114-1]15]...........-.-------------- Do.
gemma [Acrotreta], Billings [1865a, pp. 216-217]....-.-.----------------- Acrotreta gemma.
Grabau and Shimer [1907, p. 199]..-.--..------------ Acrotreta primzeva.
Hall and Clarke [1892c, p. 102, fig. 55].......-----..--- Acrotreta curyata.
Hall and Clarke [1892c, p. 102, figs. 56 and 57].....-..- Acrotreta idahoensis alta.
VWiveuloains (EY), toro, Sls occ cesskcatescescsseoncs== Acrotreta attenuata (in part), A. pyxidi-

cula (in part), A. curvata (in part), and
A. idahoensis (in part). The text in-
cludes all four species, but the last two
were the only ones figured.

Walcott [1884b, pp. 17-18, Pl. I, figs. la-b]....--....- Acrotreta idahoensis alta.

Walcott [1884b, pp. 17-18, Pl. I, figs. ld-e].....-.....- Acrotreta curvata.

SYNONYMIC REFERENCES.

gemma [Acrotreta], Walcott [1886b, pp. 98-99]

Walcott [1886b, pp. 98-99, Pl. VIII, figs. 1, la—b]
Walcott [1891a, p. 608]

Walcott [1891a, p. 608, Pl. LX VII, figs. 5 and 5a]. .
Walcott [1891a, p. 608, Pl. LX VII, fig. 5b]
Walcott [1891a, p. 608, Pl. LX VII, figs. 5ce-e]
Walcott [1899, p. 449]

Walcott [1899, p. 449, Pl. LXII, figs. 2, 2b, and 2d]...

Walcott [1899, p. 449, Pl. LXII, figs. 2a and 2c]

Walcott [1899, p. 449, Pl. LXII, fig. 2e]

gemma [Bicia], Walcott [1901, pp. 678-680]
gemma [Obolella], Billings [1872a, pp. 218-219]
Billings [1872c, p. 355]

Hall and Clarke [1892c, pp. 69 and 71]

Walcott [1886b, pp. 116-117]

Walcott [1891a, p. 612]

gemma depressa [Acrotreta], Matthew [1902c, p. 109]
Walcott [1889c, pp. 441-442]

gemmula [Acrotreta], Matthew [1894, pp. 87-88]
Matthew [1895a, p. 126]

Matthew [1903, p. 97]

gemmula [Obolella?], Matthew [1892, pp. 41-42].........................-
gemmulus [Leptobolus], Matthew [1903, pp. 190-192]..........-...-.-.---
gemmulus [Obolus (Lingulella)], Walcott [1901, p. 673]
genei [Lingulella], Pack [1906, p. 295]
Genre? sp. nebulosa Barrande [1868a, pp. 105-106]
Barrande [1868b, pp. 693-694]

gilberti [Obolus (Fordinia)], Walcott [1908d, p. 65]
girtyi [Linnarssonella], Walcott [1902, pp. 602-603]
Glossina acuminata Hall and Clarke [1892a, Pl. I, figs. 10 and 11]
(Glossina) acuminata [Lingula], Hall and Clarke [1892c, Pl. I, figs. 1 and 2].
Glossina cyane Schuchert [1897, p. 224]
(Glyptias) [Obolella], Walcott [1901, p. 675]
Walcott [1908e, Pl. XI, and pp. 142 and 145]

(Glyptias) favosa [Obolella], Walcott [1901, pp. 675-676]. -.........-...--
(Gonambonites) plana retroflexa [Clitambonites], Matthew [1895b, p. 267]. -
gracia [Acrotreta], Walcott [1902, pp. 586-587]
grandis [Leptobolus], Matthew [1894, pp. 91-92]..............---......---
grandis [Leptobolus cf.], Matthew [1902c, p. 111]

grandis [Lingulella levis], Matthew [1903, pp. 200-201] ...-..-.....--
granulata [Acrothele], Davidson [1883, p. 214]
Hall and Clarke [1892c, pp. 100-101]
Linnarsson [1876, p. 24]
Linnarsson [1877, pp. 373-374]
Swanston [1877, Pl. VII, figs. 20a—c]
Swanston [1886, Pl. VII, figs. 20a-c]
Wealleoris MESO, 1 MO oS sae cS Gcboscceccscaadees

lord

47

Present reference.

Acrotreta attenuata (in part), A. pyxidicula
(in part), and A. primeeva (in part).
The text includes all three species, but
the last was the only one figured.

Acrotreta primeeva.

Acrotreta attenuata (in part), A. pyxidicula
(in part), A. curvata (in part), A. idahoen-
sis alta (in part), and A. primeva (in
part). The text includes all five species,
but the last three were the only ones fig-
ured.

Acrotreta idahoensis alta.

Acrotreta curvata.

Acrotreta primeeva.

Acrotreta attenuata (in part), A. pyxidicula
(in part), A. curvata (in part), A. idaho-
ensis alta (in part), and A. primeva (in
part). The text includes all five species,
but the last three were the only ones fic-
ured.

Acrotreta primeeva.

Acrotreta idahoensis alta.

Acrotreta curvata.

Bicia gemma.

Do.

Acrotreta depressa.
Do.
Acrotreta gemmula.
Do.
Do.
Lingulella ferruginea.
Do.
Do.
Lingulella dubia.
Orbiculoidea contraria.
Do.
Obolus (Fordinia) gilberti.
Linnarssonella girtyi.
Lingulella (Lingulepis) acuminata sequens.
Do.
Obolus cyane.
Obolella (Glyptias).
Do.
Obolella (Glyptias) favosa.
Billingsella retroflexa.
Acrotreta gracia.
Lingulella grandis.
Does not equal Lingulella grandis.
not referred in this monograph.
Lingulella levis grandis.
Acrothele (Redlichella) granulata.
Do.
Do.
Do.
Do.
Do.
Do.

It is

48 CAMBRIAN BRACHIOPODA.

Present reference.

granulata [Discinolepis], Hall and Clarke [1892a, p. 247].-...-.-.-..------ Discinolepis granulata.
Hall and Clarke [1892b, p. 563].......----...-- Do.
Hall and Clarke [1892c, p..90].....-..--...--.--- Do.
Waagen [1885a, pp. 750—751]....-.....-.---.-..-- Do.
Waagen [1891, Pl. XI, figs. 15 and 16]....-..-..- Do.
granulata [Kutorgina], Matthew [1899a, p. 189].........-..---.---.-.---- Kutorgina granulata.
Marithew: [11899e) pi 98]|2 222. 2222--22--2-seeeene-- Do.
granulata [Mobergia], Redlich [1899, pp. 5-6]. ......-..--.-------------- Botsfordia granulata.
granvillensis [Lingulella], Delgado [1904, pp. 367-368]. -.....--.-----.--- Lingulella delgadoi.
Hall and Clarke [1892c, p. 58].......---.--.---- Lingulella granvillensis.
Ochilerty [SS Oso sels Soi eee ee Do.
Walcott [1887, pp. 188-189]. .......-..--..----- Do.
Walcott [1891a, pp. 607-608]. .......-.--.--.--- Do.
granvillensis [Lingulella cf.], Matthew [1895a, pp. 114-115]..............-- Lingulella martinensis.
gregwa [Lingulella], Matthew [1899b, pp. 199-200]. ..........--..-....... Lingulella (Lingulepis) gregwa.
gregwa [Lingulepis], Matthew [1903, pp. 56-57 and 126-131] ..-.......-.. Do.
gregwa [Obolus (Lingulepis)], Walcott [1901, pp. 692-694]............-..-. Lingulella atava (in part), L. cania (in

part), L. tumida (in part), Lingulella
(Lingulepis) gregwa (in part), and L. (L.)

exigua (in part).
gregwa robusta [Lingulepis], Matthew [1903, pp. 57 and 131] ...........-- Lingulella (Lingulepis) gregwa robusta.
groomi [Obolella], Matley [1902, pp. 137 and 139]. ..........-.--.-.------ Obolella groomi.
gulielmi [Acrotreta?], Matthew [1886, pp. 37-39]. ........-.--.---------- Discinopsis gulielmi.
gulielmi [Discinopsis], Hall and Clarke [1892a, Pl. III, figs. 20 and 21].... Do.
Hall and Clarke [1892c, ». 105].........-.--.----- Do.
H.
hamburgensis [Orthis], Walcott [1884b, p. 73]......-..-..----.---------- Eoorthis desmopleura ?.
harlanensis [Billingsella], Walcott [1905a, p. 236]......-....--.----------- Wimanella harlanensis.
hastingsensis [Orthis (Pleetorthis)], Walcott [1905a, p. 263]. ............-- Eoorthis hastingsensis.
hawker [flere til aj] Wo Wall (Ske ea eae oe reais ee ene as lars eee ee eel ee Not taken upin this monograph; it does not
equal Mickwitzia sp. undt.
hawkei? [Lingula], Bornemann [1891, p. 439]..-.-.-.-.-.------.--------- Mickwitzia sp. undt.
haydeni [Micromitra], Walcott [1908d, pp. 55-56]. -...-.-...-.-..-.------ Micromitra haydeni.
hayesi [Obolus (Lingulella)], Walcott [1898b, pp. 405-406]... ..........-. Lingulella hayes.
heberti [Lingulella], Barrois [1882, pp. 185-186]......................--- Lingulella heberti.
helena [Obolus (Lingulella)], Walcott [1898b, p. 406]....-.......-.....-- Lingulella helena.
helena [Protorthis], Walcott [1905a, p. 282]....................-.--.--.--- Protorthis helena.
Helmersenia Hall and Clarke [1892a, p. 254] ................-..-..-..-- Helmersenia.
Hall and Clarke [1892b, p. 570]. -.-...-...-...-..---..---- Do.
Islelhl eyovel Clewiies [fl Wte, jo. WIM |c o 5 - scesesseeeoceoenconsace Do.
elnlions WE, 1d: WGA] oo secesscscscessassce Hepes eta Ne Do.
Tee yalere ([eYGil, @ollunemas ASO). oo senoe sco assssebscaseeccerss Do.
Walcott [1908e, Pl. XI, and pp. 142 and 148]. ......-.-...- Do.
Zittel yA 88014 GEG see nee oe eee tte ata UE Do.
Helmersenia jeremejewi Dall [1877, p. 31].-.....--..-..-..-.-..--.-.-..-- Helmersenia ladogensis.
Oelallent [MII 10. WAM cccccccasnesecsgencasssoce Do.
Helmersenia sp.? Hall and Clarke [1892a, p. 254]. ...................---.- Do.
TEE VI gual Clarice [lee e, jo. WI). -22522-2esse22-e2s05c5 Do.
Pander [1861, columns 48-49]. .-..............- Bhat Do.
hera [Acrothele subsidua], Walcott [1908d, p. 87]. -......-...--.--------- Acrothele subsidua hera.
hicksi [Billingsella], Walcott [1905a, p. 237]...................-.-..--..-- Billingsella hicks1.
laelissr! [Orumisl, I enyeere [USER fo, SB llesesens-lsc-caseeloceescssoecasec-ace Do.
Linnarsson [1876, pp. 13-14]...-.- Jeabhl on Sane oe pom e Billingsella exporrecta rugosicostata.
hicksii [Orthis], Davidson [1868, p. 314]...............................- Billingsella hicksi.
IDenaelsor |[MIG), 19 PAO ssctosdcosesosescscusosoceesesesue Do.
highlandensis [Billingsella], Walcott [1905a, pp. 237-238] _..............- Billingsella highlandensis.
highlandensis [Orthis?], Walcott [1886b, pp. 119-120]..................... Do.
\Weaalkoora [lilksiiley, Fo, (GNA) sag sosscesssocedsoessesas Do.
Istnemellin, Wealteotnt |[MGOstel, (O; WOM |s.ccsoccccacuescsescnsecte cee cecoeseee Huenella.
Walcott [1908e, Pl. XI and pp. 142 and 148] ...-............... Do.
Huenella etheridgei Walcott [1908d, pp. 109-110]........................- Huenella etheridgei.
Huenella lesleyi Walcott [19C8d, p. 110]. ............................... Huenella lesleyi.

Huenella vermontana Walcott [new].-........-..-.--------------------- Huenella vermontana.

SYNONYMIC REFERENCES.

Present reference.

humeratus [Obolus (Schmidtia) acuminatus], Mickwitz eee pp. 184-186]. . Obolus (Schmidtia) acuminatus,

62667°—vot 51, pr 1—12—_4

49

humillima [Lingula], Barrande [1868a, p. 101]......--..-..-------------- Lingulella? humillima.
Barrande [1868b, p. 691].-.......--.-..-----.------ Do.
‘hunnebergensis [Protorthis?], Moberg and Segerberg [1906, pp. 70-71]..---- Protorthis? hunnebergensis.
I.
Ticley, |[IBiiliivoeyere nel, Io! Meta, fo, CV/ loo cscsos cocoa ac ecco scl cooee FR HOS Elkania ida.
ile, [olikeyonenp, Wtorgél [WSIIGO. joe BY esa oss o5esaagsoodeacoseeasscauoaeane Do.
Tele, {[Oloolkellleyf, Ishilibwarersy |PUXVAolte, ZA Pseeosaccsecoserocccuoe ssc osdsesuocs Do.
ida?) [Obolella]; Dawsom [1888a, p. 55] -.-2.-..-..--2.2----2------------- Acrotreta sagittalis.
IDenysOm |[Metsts] oO, jOs Gi| SoeSaoaccscsceoscasscaccdaanaccs 2c Do.
nc [KOJoollellinr ||, \WWelkeette (MESO, joo IG bsss5scecss2qes5cs0eccudscdacacess Elkania ida.
idahoensis [Acrotreta], Walcott [1902, p. 587]....-....-..-.-------------- Acrotreta idahoensis.
idahoensis [Acrotreta cfi.], Walcott [new]-...-...........-.-------+--.---- Acrotreta cf. idahoensis.
idahoensis alta [Acrotreta], Walcott [1902, p. 588].......-.-....----------- Acrotreta idahoensis alta.
idahoensis sulcata [Acrotreta], Walcott [1902, p. 588]...-.........-.--.---- Acrotreta idahoensis sulcata.
iddingsi [Orthis (Plectorthis)], Walcott [1905a, p. 264].......-....-..-..-.--Hoorthis iddingsi.
inchoans [Acrothele], Matthew [1902b, p. 404]......................-.-.-- Acrotreta inchoans.
Wena? [O03 195 WB llccsscsscadsconasscesoessesos Do.
inchoans [Acrotreta], Pompeckj [1896a, p. 3]...-.-....-.---.------------- Do.
inchoans [Lingula], Barrande [1868a, p. 102]..........-.--..---.--------- Do.
Barra de} [60868 tos) si 09 21 | ers eee Do.
indianola [Orthis (Plectorthis)], Walcott [1905a, pp. 264-265]. .......-.--- Eoorthis indianola.
indianola [Plectorthis], Grabau and Shimer [1907, pp. 251-252]. .-......-. Do.
inflata [Acrothyra?], Matthew [1901b, p. 304]..............-..------------ Acrotreta inflata.
inflata [Acrotreta], Walcott [1902, pp. 588-589]. .......-.....------------ Do.
inflata [Lingulella?], Matthew [1886, p. 33]...-...-.....--....-----..----- Do.
Werle? [WEES TDs WAM |sccscocsssscocsuscesacesbecu> Do.
Matthews (S9Sarpaal28)| see eeea eee eee eee Do.
inflata [Lingulella (Acrothyra?)], Matthew [1902b, p. 390]........-..-.-.-- Do.
inflata ovalis [Lingulella?], Matthew [1895a, p. 127]...-..-.....--------- Do.
inflatus (Obolus?|> Westergard [1909) p. 76]-..-.-.----.---------------+-- Monona: inflatus.
ingricus [Obolus], Hichwald [1829, p. 274]..................-..-..-.------Obolus apollinis ingricus.
Hichwald [1848b, pp. 140-141]. -..-....-......---.---- Do.
DiGayeAllel |EGO, jo, OAGBE|- 2-26 secsses0csscccancees Do.
vonelenchitenib ers [843% 1.6) Sees en eee ae eee Do.
ingricus [Obolus apollinis], Mickwitz [1896, pp. 137-140] .....-.........-- Do.
ino [Obolus (Lingulella)], Walcott [1898b, pp. 406—407]..---..---..-..---.- Lingulella ino.
inornatus [Obolus triangularis], Mickwitz [1896, pp. 148-149]. .........--- Obolus triangularis.
insignis [Trematobolus], Hall and Clarke [1892a, p. 252]...............---- Trematobolus insignis.
Hall and Clarke [1892b, p. 568]...-......-.-.--.-- Do.
Matthew [1893a, pp. 276-279]..-..........-..-.- Do.
Matthew [1894 pp. 88-90]- --222-2----22-------- Do.
Matthew [1895a, pp. 122-125]......._...-.-..-... Do.
Wnty (SOC, 19), ODI| scosscssccstsuscoseseaces Do.
Meni ne Nyy [EBay Oa 8Dl baccsossscaseeseooaonessccs Do.
insons [Lingula], Barrande [1879b, Pl. CV, figs. x: 1-6]..........-....--- Lingulella? insons.
insulze [Leptobolus atavus], Matthew [1903, pp. 110-112] ................. Lingulella atava insule.
intermedia [Acrothele], Gronwall [1902, p. 39].-...........-...-..-------- Acrothele intermedia.
Thimmarssony [8795 pps 25—2 ise sae sae eee eee Do.
inyoensis [Wimanella], Walcott [1908d, p. 99]. .-...-..--...-...-.-.------ Wimanella inyoensis.
rolls) ([Liioveralkey |, Tek hbase (Ese, fos MIl))|-ceaoceconaosoodess>esd5sesessce-a> Lingulella iole.
ptiidear Bally ASG Pease Nec ayace eels. sen eros ae ae etoile e Tphidea, not Micromitra. (See p. 332.)
Tew bhnyess) [REV As), Tos A ell berenacos acces see scoscuSeou san seuss Micromitra.
Ball limes [AS PAS iii ere see cS este os ese) re Eee Do.
IDM Nip Deel se celetero ne eee ek earree eta i mieten Sere ete Do.
Grabarmands shiners (907201 eee eee eee Micromitra (Paterina) (in part) and M.
(Iphidella) (in part), not true Micromitra,
Tefal eyavel Clie [MERWE os AAO) onssescaascescescasceassesoosesce Micromitra or Micromitra (Paterina).
Hall and Clarke [1892b, p. 565]..................--.-...--..----- Do.
Haliveand(Clankey[il892e cpp 97-98) a= = seee seo sere esses see eee Micromitra.
rimmarssony MSGi see Ge recis asso see loa eee eie eee ee Do.
Oellenty MSS 7m wee 7 Oller yacy aati een ISIE ele ets ie eee Do.

50 ‘CAMBRIAN BRACHIOPODA.

Iphidea Schuchert [1897, p. 233]--.-.-...----...-.---------------+------
Walcott [188GbsppelOOs10l|s-e mes eee tee, anne
Walcott [1897b, pp. 707-711].......---- UV RE UTS lta ae he

Walcott (1899) pp. 4a7a248 es ees ae e 2 see Cer
Iphidea alabamaensis Walcott [1897b, pp. 713—714]...... ----------------
Iphidea bella Billings [1872b, pp. 477-478]. .---.....--.------------------

Tehlllmargs |UVAL, Ds TOs scosonossoe=ecegseososdssooascesoess
Teullhnayeys) (MSE, 1D, WSoncossassaossocsnsoscocsodossacsosns
Clark and Mathews [1906, p. 252].......-......-..----------
Grabau and Shimer [1907, p. 201].........-..-------.-------
Halltandi(Clanke}[ili892ap ss 24.9) ae eeeee eee eee see

Hall and Clarke [1892c, p. 98, fig. 54]...........-..---.----

Present reference.
Micromitra and Micromitra (Paterina).
Micromitra.
Micromitra (in part), M. (Paterina) (in part),
and M. (Iphidella) (in part).

Micromitra.
Micromitra alabamaensis.
Micromitra (Paterina) bella.

Do.

Do.

Micromitra (Paterina) labradorica swan-
tonensis.

Micromitra (Paterina) bella. The text
includes both M. (P.) bella and M. (P.)
labradorica swantonensis.

Hall and Clarke [1892c, p. 98, Pl. IV, figs. 8 and 9]......-.- Micromitra (Paterina) labradorica swan-

Op vllerets | MEI 1s HAO LesponssanscSucossedoncesecdsqoussse

WENGE |MERG0, > UNO ssandacc sodsensdsemoadesoeseancnnase

Walcott [1S 9illasipm608]eeaseee see eee see aera

Iphidea bella? Grabau [1900, pp. 617-618]...............-.-.------------
Iphidea crenistria Walcott [1897b, p. 713]....-.--.------------------------
Tphidea labradorica Billings [1872b, p. 478].........--.------------------
y Isso vores} | MVE Os Ml booseoosenssecncesseacssesaccues
Schucherti [S89 ipw234i | Paaeee sas eeeeeese eee eee ee oee

Iphidea labradorica swantonensis Schuchert [1897, p. 234]......-.-..-----
Iphidea logani Walcott [1897b, pp. 711-712].........-......-.-.----------
Iphidea ornatella Grénwall [1902, p. 40]..........-..-------..-.---------

Hall and Clarke [1892c, pp. 97-98].-..--.-..------------

Pinnarsson-{l876, pp: 20-26]|/-----.2-2-- eee eee eee
Tphidea enf.? ornatella Hall and Clarke [1892c, Pl. IV, figs. 6 and 7]......--
Tphidea pannula Matthew [1902c, p. 110]........-.......--.-.--.---------
Jphidea pannulus Grabau and Shimer [1907, p. 201]........-.-...-..-..--

Schucherts [8974 pa 234] esses -ee see ecee es eeee eee eee
Iphidea pealei Walcott [1897b, pp. 712-713].........-.-.----.--.---------
Iphidea prospectensis Schuchert [1897, p. 234]...............-.-----------
Iphidea (??) sculptilis Meek [1873, p. 479]......----...--.----------------
Iphidea sculptilis Schuchert [1897, p. 235]............-..-..-.------------

Walcott [1899, pp. 447-448]........-...---..------------
Iphidea stissingensis Schuchert [1897, p. 234].............--.------------
Iphidea superba Walcott [1897b, p. 711].--....---....-..-.--.------------
Iphidea swantonensis Grabau and Shimer [1907, p. 201] .................-.

Iphidea sp. undet. Walcott [1899, p. 449]...............-..----.----------
Tphidella Walcott [1905a, p. 304]..........-....................-..--.----
(Iphidella) [Micromitra], Walcott [1908e, Pl. XI, and pp. 142 and ae
Iphidella labradorica Walcott [1905a, p. 307]... j
[phidella labradorica orientalis Walcott [1905a, ap. 305-306]. .

Tphidella labradorica swantonensis Walcott [1905a, p. 307]....-..-.-.-----
Tphidella labradorica utahensis Walcott [1905a, p. 306]....-.....----..---
(Iphidella) louise [Micromitra], Walcott [1908d, pp. 56-57]
Tphidella major Walcott [1905a, p. 304]

Tphidella nisus Walcott [1905a, p. 305]

tonensis. The text includes both M.
(P.) labradorica swantonensis and M.
(P.) bella.

Micromitra (Paterina) bella.

Do.
Micromitra (Paterina) crenistria.
Micromitra (Paterina) labradorica.
Do.

Micromitra (Paterina) labradorica (in part)
and M. (P.) labradorica swantonensis
(in part).

Micromitra (Paterina) labradorica swan-
tonensis.

Micromitra (Paterina) logani.

Micromitra (Iphidella) ornatella.

Do.
Do.
Micromitra (Paterina) superba.
Micromitra (Iphidella) pannula.
Do.
Do.

Micromitra pealei.

Micromitra (Paterina) prospectensis.

Micromitra sculptilis.

Do.
Do.

Microritra (Paterina) stissingensis.

Micromitra (Paterina) superba.

Micromitra (Paterina) labradorica swan-
tonensis.

Micromitra sp. undt.

Micromitra (in part), M. (Paterina) (in
part), and M. (Iphidella) (in part).

.-Micromitra (Iphidella).

.-Micromitra (Paterina) labradorica.

Micromitra (Paterina) labradorica orien-
talis.

Micromitra (Paterina) labradorica swan-
tonensis.

Micromitra (Paterina) labradorica utahensis.

Micromitra (Iphidella) louise.

Micromitra (Paterina) major (in part) and
M. (P.) williardi (in part).

Micromitra nisus.

SYNONYMIC REFERENCES. pil

Present reference.

(Iphidella) nyssa [Micromitra], Walcott [1908d, p. 57].-.-.----.----------- Micromitra (Iphidella) >»yssa.
Tphidella pannula Walcott [1905a, p. 307]... ae . -Micromitra (Iphidella) pannula.
(Iphidella) pannula [Micromitra], Walcott [1908c, . 244, Pl i, ‘ize. il, tae). Do.
Tphidella pannula maladensis Walcott [1905a, p. 306]. - ..-----------Micromitra (Iphidella) pannula maladensis.
Tphidella pannula ophirensis Walcott [1905a, p. 306]........--.----------- Micromitra (Iphidella) pannula ophirensis.
Tphidella prospectensis Walcott [1905a, p. 307].........----------------- Micromitra (Paterina) prospectensis.
Tphidella sculptilis Walcott [1905a, p. 308]......-..--------------------- Micromitra sculptilis.
Tphidella stissingensis Walcott [1905a, p. 308]..........-.--.------------ Micromitra (Paterina) stissingensis.
Iphidella sp: undt. Walcott [1905a, p. 305]_.-.....-..-----------.----.-- Micromitra sp. undt.
iphis [Obolus (Westonia)], Walcott [1905a, p. 336]....--..--.----.-------- Obolus (Westonia) iphis.
irene [Lingula], Billings [1862d, pp. 71-72]..............--.-------------- Lingulella irene.
Isbin gss [MEGS 19, ZE0| booacaccas cncoseoscossossndsoscuaes Do.
inene|[Lineulella|) Schuchert [i1897, p. 257|..-.-.---------5----+---------- Do.
Tig) |Join), Iekibitiavess) | SY, Ts COE acesescoccosncascsacsaeoassascaanesc Lingulella iris.
ismene [Obolus], Walcott [1905a, p. 325]...--..--------------2-----+------- Obolus ismene.
isse [Obolus (Lingulella)], Walcott [1905a, p. 330]...--..---.--..--------- Lingulella isse.
J.
(Jamesella) [Nisusia], Walcott [1905a, p. 252]..........-.----..-----5------ Nisusia (Jamesella).
Walcott [1908e, Pl. XI, and pp. 142 and a, pa eebeee Do.
(Jamesella) amii [Nisusia], Walcott [1905a, p. 252]-.- ---------- -------Nisusia (Jamesella) amii.
(Jamesella) argenta [Nisusia], Walcott [1905a, p. 252]. ate onaige ee Meee Nisusia (Jamesella) argenta.
(Jamesella) erecta [Nisusia], Walcott [1905a, p. 253]........---..-..------ Nisusia (Jamesella) erecta.
(Jamesella?) kanabensis [Nisusia?], Walcott [1908d, pp. 97-98]....-..-.--- Nisusia? (Jamesella?) kanabensis.
(Jamesella) kuthani [Nisusia], Walcott [1905a, pp. 253-254].......-..---.- Nisusia (Jamesella) kuthani.
(Jamesella) lowi [Nisusia], Walcott [1908d, p. 98].- eer ..----.----Nisusia (Jamesella) lowi.
(Jamesella) perpasta [Nisusia], Walcott [1905a, pp. 254-255]... i arareshaais SP ere Nisusia (Jamesella) perpasta.
(Jamesella) perpasta macra [Nisusia], Walcott [1905a, p. 255].........-.--- Nisusia (Jamesella) perpasta macra.
(Jamesella) perpasta subquadrata [Nisusia], Walcott [1905a, p. 255]....---- Nisusia (Jamesella) perpasta subquadrata.
(Jamesella) utahensis [Nisusia], Walcott [1905a, pp. 255-256].........--..-- Nisusia (Jamesella) utahensis.
(Jamesella) sp. undt. [Nisusia], Walcott [1905a, p. 256] ....-..-......------ Nisusia (Jamesella) sp. undt.
jeremejewi [Helmersenia], Dall [1877, p. 31]......-.--..------.----------- Helmersenia ladogensis.
Oehlert)[V88i7spy L264] Bees aaseete eee eee Do.
johannensis [Orthis (Plectorthis)], Walcott [1905a, pp. 265-266].-....-- -....-Eoorthis johannensis.
johannensis [Orthisina (?)], Matthew [1892, pp. 49-50]......-.......---.--- Do.
K. “
kanabensis [Nisusia? (Jamesella?)], Walcott [1908d, pp. 97-98]....-..-.-.--- Nisusia? (Jamesella?) kanabensis.
kayseri [Orthis (Plectorthis)], Walcott [1905a, p. 266].........-...---...-- Eoorthis kayseri.
kempanum [Protosiphon], Matthew [1897a, pp. 70-71].-....---....--.----- Trematobolus kempanum.
Matthew [1898a, p. 131]....-........--.-------- Do.
lenpscribiaysaie) IDEN PISH/T/ai10b GH) Eadnsacboaeans sane setbancosaosasoandaocecar Keyserlingia.
Hall and Clarke [1892c, pp. 117-119]..................-...-- Do.
Karpinskyy [18875 pa AiG sacra ance eiiecienee eee eeeene aac Helmersenia, not Keyserlingia.
(Opel allerat, MSS 7/6 Ts WAT EcconecoccousaeocescnsoedcaudasvaccuncGS Keyserlingia.
Pander [lSGl5 yp. 4G] oases secu cow once ects sweetener Do.
Walcott [1908e, Pl. XI, and pp. 142 and 146]..-.............. Do.
Keyserlingia buchi Hall and Clarke [1892c, p. 118]....-..-.--..-.-...-..- Keyserlingia buchi.
Pander [1861, columns 46-48]...........----.-.-...-- Do.
Keyserlingia panderi Karpinsky [1887, p. 476].......-..-.-.-----..------ Helmersenia ladogensis.
kichouensis [Orthis (Plectorthis)], Walcott [1906, p. 570]......-.-....--...-Eoorthis kichouensis.
kiurensis [Lingula?], Waagen [1885a, pp. 768-769]..............--.--..--- Lingulella kiurensis.
Waagen [1891, Pl. Il, figs. 17a-b]|......-..-.--...... Do.
kuthani [Nisusia (Jamesella)], Walcott [1905a, pp. 253-254].....-.......... Nisusia (Jamesella) kuthani.
kuthani [Orthis], Pompeckj [1896b, pp. 514-515].......-..-...--..---..... Do.
kutorgai [Acrotreta], Walcott [1902, pp. 589-590]...................--.---- Acrotreta kutorgai (in part) and A. rudis
(in part).
Kutorgina Beecher [1891, pp. 345-346]..........-.------+--+-+-------2ee0-e Kutorgina.
Billines\|s6llbspe Olesses: «2c - soe ee eee here sae eee Do.
Billimesi | S6ilemps 948 senate = ara eel eral eee ee eee neers Do.
Teiilbravers [MEH Tos PAD go aseasecocsardodecadosaosucoooesacases Do.
Dal WS Tipp y40—4U son oscceces concer ccansn Seeeeee eae Micromitra (Paterina) (in part) and Kutor-

gina (in part).

52 CAMBRIAN BRACHIOPODA.

Present reference.

Kertoreinae) ava dsony [SCS empresa ee es eee ee Kutorgina.
Davidson: [87 epi342 esas o8 se saete sai sects es seo Do.
GrabauvandlS hime |i90/7-i ps2 09) Steeeeseeee eee eee Do.
Hall and Clarke [1892a, pp. 247-248].........----------------- Do.
Hall and Clarke [1892b, pp. 563-564]............----.-----:--- Do.
Hall and Clarke [1892c, pp. 90-94, and 183]...--...---.---.---- Micromitra (in part), Micromitra (Paterina)

(im part), Micromitra (Iphidella) (in
part), Kutorgina (in part), Protorthis (in
part), and Billingsella (in part).
Oehlerts[1887,\pael262i| eee ss eee eer ar cray= es tera rere Kutorgina. ;
Walkeouty [IOS joo. WON=MO2|, 2s 525scccesacoacoccuncssasssecce Kutorgina (in part), Micromitra (in part),
Micromitra (Paterina) (in part), and
Micromitra (Iphidella) (in part).

Walcott l90bappas06—308)] peeee essa sree aee eer se eee Kutorgina.
Walcott [1908e, Pl. XI, and pp. 142 and 145]..............---- Do. ;
Tiittell [180s G64] ae aeemn ef cas aia pent a oust Do.
(Kutorgina) [Obolella], Dall [1870, pp. 154 and 163]............-....--.-- Do.
Kutorgina alata? Moberg [1892b, p. 113].....--..-.-.--.-..---------------Belongs with an undetermined genus.
Kutorgina cingulata Beecher [1891, pp. 345-346]........-.....-..--.------ Kutorgina cingulata.
Bornenvanny [8916p 1440) eases ae eee ease eee Kutorgina sardiniaensis.
Dawidsont|lSGSs parol] saseeeee asa ee eee eee ae ser Micromitra (Paterina) phillipsi.
Davidson [1871, pp. 342-343]......-.-.--.-.---------- Do.
IDnyatelstoya, |B), 15, MI ononaccadeoaodnec=dsescs0nace Do.
lpeen, [eR 5 IAL IVA, tes, CAI) cesenccesose Sscqsensss Kutorgina cingulata.
Grabau and Shimer [1907, p. 209] ...--.----..--.---.- Do.
Hall and Clarke [1892a, Pl. IV, figs. 11-13].....-....-- Do.
Hallvands@lankey|il892¢% ps 92)|tasse= ane aes e eee eee Do.
WOM ANGI UE), [09> APB ess swords ssecosensescosece Do.
Walcott [1886b, pp. 102=104]......-.--..-.------.--- Micromitra pusilla (in part), Micromitra

(Paterina) phillipsi (in part), and Kutor-
gina cingulata (in part).
Walcott [1886b, pp. 102-104, Pl. IX, figs. 1, la-f] .... Kutorgina cingulata.

Walcott [1886b, p. 103, Pl. LX, figs. lg-h]...........- Rustella edsoni.
Walcott [1891la, p. 609, Pl. LXIX, figs. 1, la-f]......- Kutorgina cingulata.
Walcott [1891a, p. 609, Pl. LXIX, figs. Ig—h]......-- Rustella edsoni.
Walcott [1905a, pp. 308-309]. .........---.------.--- Kutorgina cingulata.
(Kutorgina) cingulata [Obolella], Billings [1861b, pp. 8-9, figs. 8 and 10]-- Do.
Billings [1861b, p. 8, fig. 9]-..---.--.-.--- Rustella edsoni.
Billings [1861c, p. 948, figs. 347 and 349].. Kutorgina cingulata.
Billings [1861c, p. 948, fig. 348].......-..- Rustella edsoni.
Billings [1862e, p. 220, figs. 347 and 349]. . Kutorgina cingulata.
Billings [1862e, p. 220, fig. 348].......-.- Rustella edsoni.
Kutorgina cingulata phillipsi Matley [1902, pp. 145-147].-............-.--- Micromitra (Paterina) phillipsi.
Kutorgina cingulata pusilla Grénwall [1902, pp. 40-41]..............-...-- Micromitra pusilla.
ILabaumendststorn |[MSTG, 1s ZO |ssacaccesecaaseasoeses- Do.
Matley (1902, pp: 146-147)....-........-.-..-- Do.
Kutorgina eranulata Matthew [1899a, p. 189]...--.-.-.----...-..--.-.-----Kutorgina granulata.
Matthew: [1899ernp uO Sie eaeeine cee toe ee ere eee Do.
Kutorgina labradorica Walcott [1886b, p. 104]....--.......-.--------------Micromitra (Paterina) labradorica. The

figures accompanying this reference
[Pl. LX, figs. 2, 2a—b] represent M. (P.)
labradorica swantonensis.

Walcott [1886b, Pl. 1X, figs. 2, 2a-b].......-.--... Micromitra (Paterna) labradorica swan-
tonensis. The text reference [p. 104]
refers only to M. (P.) labradorica.

Welker |e Miley, os GOO | coascccogeacsucatcouccossoes Micromitra (Paterina) labradorica.
Kutorgina labradorica swantonensis Walcott [1890b, p. 36]--.--.---------- Micromitra (Paterina) labradorica swan-
tonensis.
Walcott [1891a, p. 609] ...-----..----- Do.
Kutorgina latourensis Hall and Clarke [1892c, pp. 93, 95, and 233].....-.-- Protorthis latourensis.
Matthew [1886, pp. 42-43] ............-------.-.-- Do.

Kutorgina minutissima Hall and Whitfield [1877, pp. 207-208].......-..-. Micromitra sculptilis.

SYNONYMIC REFERENCES. 53

Kutorgina pannula Pack [1906, p. 296].....-..-.---------
Walcott [1886b, p. 105]. ---..---.2---:

Walken | ESY, Tos UG O)|-sceacesssscte sss

Walcott [1891a, p. 609]....-...---.-----

Kutorgina perugata Walcott [1905a, p. 310].-......--..---
Kutorgina prospectensis Walcott [1884b, p. 19]
Walcott [1886b, pp. 106-107]

Walcott [1891a, p. 610]

Kutorgina sardiniaensis Walcott [1901, p. 695]
Walcott [1905a, p. 311]

Kutorgina sculptilis Walcott [1884b, p. 20]....-...-..-----
Kutorgina stissingensis Dwight [1889, pp. 145-147]
Dypriethih (MUM) fe AMOD||.'5s.-stccee suse okboeeeaence

-Kutorgina undosa Moberg [1892b, p. 112]........-.-..---
Kutorgina whitfieldi Walcott [1884b, pp. 18-19]
Kutorgina sp. Moberg [1892b, p. 114].................-.--

Kutorgina sp. undt. Walcott [1905a, p. 311]

labiosa [Discina], Salter [1866a, p. 285]............--.-----

labradorica [Iphidea], Billings [1872b, p. 478]
Billings [1874, p. 76]............---
Schuchert [1897, p. 234]

labradorica [Iphidella}, Walcott [1905a, p. 307]
labradorica [Kutorgina], Walcott [1&86b, p. 104]

Walcott [1886b, Pl. IX, figs. 2, 2a—b]

Walcott [1891a, p. 609]
labradorica [Paterina], Beecher [1891, pp. 345-346]

Hall and Clarke [1892a, p. 247]
labradorica orientalis [Iphidella], Walcott [1905a, pp. 305-306]

labradorica swantonensis [Iphidea], Schuchert [1897, p. 234]

labradorica swantonensis [Iphidella], Walcott [1905a, p. 307]
labradorica swantonensis [Kutorgina], Walcott [1890b, p. 36]

Walcott [1891a, p. 609]
labradorica utahensis [Iphidella], Walcott [1905a, p. 306]

labradorica var. undt. [Micromitra (Paterina)], Walcott [new]
NP ea ie eee Micromitra (Paterina) labradorica.
Pee et ee ciae = ct oeiot nie ee Do.
LESS osch ao aORroen eee ters Sree s Do.

labradoricus [Obolus], Billings [1861b, p. 6]

Billings [1861c, p. 946]
Billings [1862e, p. 218]
Billings [1863, p. 284]...-..-.---
ladogensis [Siphonotreta], Jeremejew [1856, pp. 73 and
levis [Acrothele subsidua], Walcott [new]-..-..-..--.-...-
levis [Lingulella], Matthew [1892, p. 39] ........-.--....--
levis [Protorthis], Walcott [1905a, p. 283] .....-.--....-.--
levis grandis [Lingulella], Matthew [1903, pp. 200-201]
levis lens [Lingulella], Matthew [1903, pp. 201-203]

se, ae Lee Do.

ee ise steer Micromitra sculptilis.

ele Nae eee Do.
semi e ae > Do.
Win eerekiece clo ames Micromitra (Paterina) labradorica utah-

Present reference.
Micromitra (Iphidella) pannula.
Do.
Do.

Kutorgina perugata.

Micromitra (Paterina) prospectensis.
Do.
Do.

Kutorgina sardiniaensis.
Do.

Micromitra (Paterina) stissingensis.
Do.

Ss bape A ree tele es Micromitra (Paterina) undosa.

Billingsella whitfieldi.
Micromitra? sp. (See p. 357.)
Kutorgina sp. undt.

Acrotreta sagittalis.

Beta B Up ace ENINS Hee gM W Micromitra (Paterina) labradorica.

Do.
Micromitra (Paterina) labradorica (in part)
and M. (P.) labradorica swantonensis (in

part).

Lear erate iS Ce TSS elas Brera Micromitra (Paterina) labradorica.

Micromitra (Paterina) labradorica. The
figures accompanying this reference
[Pl. IX, figs. 2, 2a-b] represent M. (P.)
labradorica swantonensis.

Micromitra (Paterina) labradorica swanton-
ensis. The text reference [p. 104] refers
only to M. (P.) labradorica.

Liaise oS estas eye r= Meee ate Micromitra (Paterina) labradorica.
Bes See ee een Micromitra (Paterina) labradorica swanton-

ensis.

BAe aeirs etn eet Aen Do.

Micromitra (Paterina) labradorica orien-
talis.

Micromitra (Paterina) labradorica swanton-
ensis.
Do.

ensis.
Micromitra (Paterina) labradorica var. undt.

Do.

Ee RBS AAAs Helmersenia ladogensis.

Acrothele subsidua levis.
Lingulella leevis.

Gp git Mise = fap Coote Protorthis leevis.
BU Aaneneue eee Rane Lingulella levis grandis.
BBE Saauosae See eee Lingulella lens.

Jeviusculus [Orthis (Plectorthis) wichitaensis], Walcott [1905a, p. 272] .. ..Eoorthis wichitaensis leviusculus.

lzeviusculus [Syntrophia texana], Walcott [1905a, pp. 294-295] ...........
Lakhmina Hall and Clarke [1892a, pp. 234-235]
Hall and Clarke [1892b, pp. 550-551]
Hall and Clarke [1892c, pp. 28-30]
(ylalleray MES, Toy WHE Lo ibasscecesonaccasscosce
Waagen [1891, desc. of Pl. II, figs. 3 and 4]

-Huenella texana leeviusculus.
Ch NS ates raya eran ray Neobolus.

ees Vo OC aee IEE Do.

Peano pons CanaGs essa shee ens Do.

Seemaetyaieceeicts Do.

Wsferato oe tears pavchaictereye Sere Do.

54 CAMBRIAN BRACHIOPODA.

Present reference.

Lakhmina linguloides Frech [1897, Pl. IA, figs. 4a-b]...................- Neobolus warthi.
Hall and Clarke [1892a, p. 234]........-.......-.--- Do.
Hall and Clarke [1892b, p. 550] .....-.--........--. Do.
Hall and Clarke [1892c, p. 28]................-..... Do.
Oye alerts |ESV/, tos WAG |.< scasasonescsedssecocsecoos Do.
Waagen [1891, desc. of Pl. II, figs. 3 and 4]......... Do.
lamborni [Lingulella], Keyes [1894, pp. 38-89].....-.......-...-.-.-..--- Obolus lamborni.
lamborni [Lingulella?], Meek [1871, pp. 185-187].......................-- Do.
lamborni minimus [Obolus (Lingulella)], Walcott [1898b, p. 407]..-...-...- Obolus lamborni minimus.
lamellosa [Lingula], Barrande [1879b, Pl. CVI, figs. 1: 1-5; Pl. CXI, figs. 1x:
15) beodce Dae bGanoe Sadao pos ron stos SsepaneEsoaes saan SusedaseasaueosonS Obolus (Westonia?) lamellosus.
lamellosus [Obolus (Westonia?)], Walcott [1901, p. 691]...............--.. Do.
lata [Acrothele matthewi], Hall and Clarke [1892a, Pl. III, figs. 25and 26] ..Acrothele matthewi lata.
Hall and Clarke [1892c, Pl. IIT, fies. 26-28]... .. Do.
Matthew, [18865 p. 41i|22-22.------55--+s---e ene Do.
Matthew [1895a, Pl. V, figs. 8a-b] .-..-.-.---.- Do.
Weyriaesy7 |MGO3, Ds ON) ssccce scssaccossnacecce Do.
lata [Acrotreta papillata], Matthew [1903, pp. 95-96].......- fA mene sae Nets Acrothyra, sera.
lateralis [Syntrophia], Hall and Clarke [1892c, p. 270].....--...-.......--- Syntrophia lateralis.
Hall and Clarke [1898b, p. 217]............--...-.-- Do.
fall [1804a) ps Sail asa cceceteleis le eoteteietes eee Do.
lateralis [Triplesia], Whitfield [1886, p. 303]....-..........-...-...------- Do.
latourensis [Kutorgina], Hall and Clarke [1892c, pp. 93, 95, and 233]. ..... Protorthis latourensis.
Matthew [1886, pp. 42-43]..............--.--.---- Do. i
latourensis [Protorthis], Walcott [1905a, pp. 282-283]... ae See Do.
latus [Obolus (Schmidtia) obtusus], Mickwitz [1896, a. 174-175). - Bi eee ae Obolus (Schmidtia) obtusus.
leda [Obolus tetonensis], Walcott [1908d, p. 63]......-......-.-.---.----- Obolus tetonensis leda.
lens [Lingula?], Matthew [190la, pp. 274-275]..........-..---..--------- Lingulella lens.
lens [Lingulella], Matthew [1903, pp. 205-206].......-. Wes ec cae ae aaa Do.
lens [Lingulella levis], Matthew [1903, pp. 201-208] ......--......-.--.--- Do.
Hers} (@bolus| SMvrartithre wa il'902 creo 5) epee eet ea Obolus (Paleeobolus) bretonensis lens.
lens [Obolus (Lingulella)], Walcott [1902, pp. 606-607] ..........-.......- Lingulella lens.
lens [Obolus (Paleeobolus)], Matthew [1903, pp. 144-146] ...............-- Obolus (Palzeobolus) bretonensis lens.
Jens longus [Obolus (Palzeobolus)], Matthew [1903, pp. 146-147]. ........- Do.
lens-primus [Obolus], Matthew [1902c, pp. 94-95]....--..--.......-.---.-- Do.
lenticularis [Anomites], Wahlenberg [1821, pp. 66-67]..-...--..-....---.-- Orusia lenticularis.
lenticularis [Atrypa?], Dalman [1828, pp. 132-133].--...........----.-.--- Do.
labistuaryerr [IRE > [Ollcococandasossoudecaoocasscasc Do.
lenticularis [Atrypa], Kjerulf (1857, p. 92]...2-..-.-...--.-------.-------- Do.
Teajenrwlle |[1S(G}5}, joy, WL ein! B]cossconsessessesascsocses Do.
leqyerqulbi | Hey ele OUUY ANG ocnbecemaeesesdeaaaee an Do.
lenticularis [Orthis], Brogger [1882, p. 48].....-------.----- Peseta tyes Sina Do.
(Denvaraksorn |[USNtS)5 fos BI ceo aes dacccghassepedacsessadc Do.
Davidson [1869, pp. 230-232]. .....-...-.-------.--- Do.
Matthew [1892, pp. 46-48].......-........------..--- Do.
Martitive wa [9035s ppm 2il3o—21 6) bese eee seen sear Do.
Roemer [1876, Pl. Il, figs. 4a-c].............-.....-- Do.
Roemer |[l8sb; ppscs—34 ee een ee eeeceeas ee eeee ce eae Do.
rstlkisye |[SIHGO, (Os BHM boecasseaeessscsbosoccssascsso- Do.
Salter and Etheridge [1881, pp. 544-545]............. Do.
lentieularis a [Oxthis) je heny sen) [MSi165 ups o) | see eee ere Do.
lenticularis [Orthis (Orusia)], Walcott [1905a, pp. 273-276]..........-..--- Do.
lenticularis [Spirifera?], von Buch [1834, p. 48]....-.-..--..-.-..-.....--- Do.
lenticularis atrypoides [Orthis], Matthew [1892, p. 48]....-..--..-.--.-.-- Orusia lenticularis atrypoides.
Matthew [19038, p. 217]...------.--- Siam Do.
lenticularis atrypoides [Orthis (Orusia)], Walcott [1905a, p. 276]. ....-...-- Do.
lenticularis lyncioides [Orthis], Matthew [1892, p. 49]..................-- Orusia lenticularis lyncioides.
Matthew [1903, p. 216].........------...- Do.
lenticularis lyncioides [Orthis (Orusia)], Walcott [1905a, p. 277].--.-......- Do.
lenticularis strophomenoides [Orthis], Matthew [1892, p. 49].............. Orusia lenticularis.
Matthew [1903, p. 217]...........-. Do.
leos [Obolus (Lingulella)], Walcott [1898b, pp. 407-408] ........-..-.-..-. Lingulella leos.

lepis [Lingula?], Davidson [1866, p. 54]..........-.---..-.--------------- Lingulella lepis.

SYNONYMIC REFERENCES. 55

Present reference.

leyeria) |Link, Shullieye |RSS Toney i]s 6 sceaqosasobsondsusscadesoreoeeose Lingulella lepis.
lepis [Lingula (Lingulella?)], Brégger [1882, p. 44]...........--.--------- Do.
lepis [Lingula (Lingulella)], Davidson [1866, desc. of Pl. III] -............ Do.
lepis [Lingulella], Davidson [1868, pp. 307-308]...........-.------------- Do.
Davidson [1871, Pl. XLIX, figs. 31 and 3la]-.-.....-..--- Do.
1a{ollieay| UCR Sa alte noe cadeeseecusuos oe ouedeeaaeador Do.
: Moberg and Segerberg [1906, pp. 62-63]....-.--.------- Do.
Salterslil S66}, 7334] sakes ee ere te aL nn om Gis Do.
Salter and Etheridge [1881, p. 538].-----.--.----------- Do.
lepis [Lingulella cf.], Matthew [1903, p. 204]. ..-....-..-.---.------ ees Do.
lepis? [Lingulella], Westergard [1909, p. 57]. ...-.--.-------------------- Do.
Warmer |[I902, (aos OB ancl 7ll)|.-ceososascenccsocsesocescs Do.
Lepteena barabuensis Whitfield [1878, p. 60]..................-.-.------- Syntrophia barabuensis.
Whitfield [1882, pp. 171-172 and 195] ....--...--.--- Do.
Lepteena melita Hall and Whitfield [1877, p. 208]. ....-..-.--.---------- Variety of Eoorthis desmopleura.
(Leptembolon) [Obolus], Mickwitz [1896, p. 199]...........-..------.--- Lingulella (Leptembolon).
Walcott [1908e, Pl. XI, and pp. 142 and 144]..-. Do.
(Leptembolon) linguleeformis [Obolus], Mickwitz [1896, pp. 200-204] . . . .. Lingulella (Leptembolon) lineulzeformis.
(Leptembolon) lingulzeformis solidus [Obolus], Mickwitz [1896, pp. 204-205] Do.
Leptobolus Matthew [1903, pp. 105-106]. .......-....-..---.---+--------- Lingulella.
Leptobolus atavus Matthew [1899b, pp. 200-201].-.........--.-...------- Lingulella atava.
Matthew [1903, pp. 106-109]..............--.....----- Do.
Leptobolus atavus insule Matthew [1903, pp. 110-112] -................-- Lingulella atava insule.
Leptobolus atavus tritavus Matthew [1903, p. 109].....-....--...--.------ Lingulella torrentis.
Leptobolus? collicia Matthew [1899b, p. 200].-.......---..---.----------- Lingulella collicia.
Leptobolus collicia Matthew [1903, pp. 112-113].-.........-...-..-.-.---- Do.
Leptobolus collicia collis Matthew [1903, pp. 114-115]..........-...--..--- Do.
Leptobolus flumenis Matthew [1903, pp. 189-190].......-.....--..--.----- Lingulella flumenis.
Leptobolus gemmulus Matthew [1903, pp. 190-192]..............-.-----.- Lingulella ferruginea.
Leptobolus grandis Matthew [1894, pp. 91-92]....-....-...--..--.-------- Lingulella grandis.
Leptobolus cf. grandis Matthew [1902c, p. 111].-..---..---...---.---.--- Does not equal Lingulella grandis. It is not
i referred in this monograph.
Leptobolus linguloides Matthew [1902b, p. 407] ..-...--.----------------- Lingulella ferruginea.
IWiniilneyy7 |MOUS, > IRB e sncsceoceusssccccodesoecens Do.
Leptobolus cf. linguloides Matthew [1902b, p. 407]....-.......--.--------- Do.
Matthew [1903, pp. 192-193].....-..--..-----.-- Do.
Leptobolus torrentis Matthew [1903, pp. 74-75]. ..-....-..--------------- Lingulella torrentis.
lesleyi [Huenella], Walcott [1908d, p. 110]........-..--...-..---..---.-- Huenella lesleyi.
levisensis [Acrothele], Walcott [1908d, p. 85]. ...--.....-.--.------------ Acrothele levisensis.
liani [Acrotreta], Walcott [1905a, p. 300]..............---..-....-..--..-- Acrotreta lisani.
liméensis [Acrotreta], Wiman [1902, p. 54]..............-..-------------- Acrotreta uplandica liméensis.
limonensis [Acrotreta uplandica], Walcott [1905a, p. 303]....--........-.-- Do.
lindstromi [Billingsella], Walcott [1905a, pp. 238-239]................-...- Billingsella lindstrémi.
lindstrémi [Obolella], Walcott [1901, pp. 674-675]................-..----.-Obolella? lindstrémi.
lindstrémi [Orthis], Linnarsson [1876, pp. 10-12].............-.---.--.-.- Billingsella lindstrémi.
lineolatus [Obolus (Lingulella)], Walcott [1898b, pp. 408-409]...........-.. Lingulella lineolata.
Lingula acuminata Billings [1863, p. 102]...............-..-.----..------ Lingulella (Lingulepis) acuminata.
Chapa WEG, 1, IS. cccassecccusocegsauecesucease Do.
Chapmant|i'864 5h pelo 9) [Reet eee eee esac eee eee eee Do.
Conrady [W839 ep.164] Seat nace eee ae eee ace Do.
fDpaaurarosatel [ICH ey PANE] VaR eee eae Nn Rens ea Do.
foe CHW Oyo) See ho a Oe eos Sens eS ana oe Do.
Lingula acutangula Roemer [1849, p. 420].............--.---.---.---.-.- Lingulella acutangula.
Roemer) [ll8525p 400) eeeses- cere seieee beeen eee Do. ,
Lingula agnostorum Wallerius [1895, pp. 64-65]....-.....-....-..--------- Lingulella agnostorum.
ILimorel, exemyolley ISU |PUXGRY fos WI 6 Seolscen ce sacceooeescdsdnouenocanosns Lingulella ampla.
La S Gia peel Ol S102) ee sae eee eee eee ee Do.
Oye (Mes), 1s Wee) Saisseebeossoecnscseenccoceseeccundaoe Do.
Lingula ancilla Barrande [1879b, Pl. CXI, fig. vi]..........-..-..-..-..-- Obolus? ancillus.
Lingula antiqua Billings [1856, p. 34]..........--..--.---..--.----------- Lingulella (Lingulepis) acuminata.
JOyoarmn opts [UHR (Os Aetsl|> ccssecsosescossane-55eesesqcsess Do.
1Dyrouanoraly [ING Do Glass soscocosceoeousooscosdsunsecads Do.

as AS47 ppp voH 4] SoS os aera tare eclarelop he ciel oie eles oes Do.

56 CAMBRIAN BRACHIOPODA.

Present reference.

Lingula antiqua Hall [1851, pp. 204-205]............--..--.------------- Lingulella (Lingulepis) acuminata.
Hall [S62 ait ces 2 so spoilt sree eee ore Es Sco 2 ee Do.
Haydeny [8628 pies] Seance eas asia so 2c\-/a2) oe Soe Do.
Jamies: [L895 KpRnSS4kae Aas facets asco: ae eee Do.
Ovween {[US Sie Orel Oy] eee eee ete aie SP 0 Fp tes ear Do.
Rogers [lS 6lemonts 90) ee mee sae ae alas ashy fea rere Obolus (Westonia) rogersi.
Lingula antiquata Emmons [1855, pp. 202-203] ..........--.---.--------- Lingulella (Lingulepis) acuminata.
Lingula attenuata Bornemann [1891, pp. 437-438]. ......--..------------ Lingulella bornemanni.
inowlayaurorayeallly il S612 24 | Seen eee es eee es Obolus (Westonia) aurora.
Lat [S625 so) sl Soe eee eta Brae eae ered i Ane) oe cei Pe Do.
TETal [i863 sp pagel 26m 11217) | ees ere ee Sate Do.
‘Halll [1 867sppan OS LO4 [Syed Gia ence oo: rms Do.
Sermalesern (MENS, 70. Cll. se oesscecnasscoccscessoesccdacuacs Do.
ineula aurora var. Hall) (1863, pp: l27 128-2 22222222 25222222222 sss Obolus (Westonia) stoneanus,
ISU IB/, 1D> OLA OD ||, 6 2502 sossecccesenseesscuces Do.
Lingula bavarica Barrande [1868a, p. 100].-....--...-.....--..----.--- Obolus? bavaricus.
Barrande [1868b, pp. 690-691]. -..-...---...-..----- Do.
Lingula belli Billings [1859, pp. 431-432]....-.........-.........-.-..- Obolus belli.
Billings (1863. figs. 47a=b, p. 124]-.--..-----------+.-.-- Do.

Lingula billingsana Matthew [1903, p. 200]. -.-....--.-....--...--..-

Lingula billingsiana Whiteaves [1878, p.226].......--....-

Lingula cf. billingsiana Matthew [1894, p. 93]...-.....------.--------
Ibmaysmley leona, \Winanein (GOA, Jo, Bille = = = =o -sessence see sandsosesssse
Lingula? bryograptorum Moberg and Segerberg [1906, p. 63]....-.-..---
\Wiesteuseinel (MIGOS), (os BWlacesseacanascossccee sc

Lingula cedens Barrande [1868a, p. 102]. -........-..------.-.--..----
Barrande [1868b, pp. 691-692]. -.......-.-.-.-.--.....-

Lingula? corrugata Moberg and Segerberg [1906, p. 63]. --.--..---------
Westiaqeinel (IGS), iO. Bi], dose ssoscacsccpnbocsecss

Lingula cyane Billings [1865a, p. 216]..................-....-.-...--.-
Lingula dakotensis Meek and Hayden [1865, p. 3]..-...-..-----.------
Whitfield [1880, pp. 337-338]_.----.:..-.-----------

Lingula davidsoni Barrande [1879b, Pl. CIV, figs. virr: 14]

Lingula davisi McCoy [1851b, pp. 405-406]... ...--...---..----.------
MMe Cosy, [Shang 252i ta cated RUN Ogee yon oe ae eeearele

Lingula cf. davisi Schmidt [1881, p. 17, fig. 5]....-...---.-----.------
Lingula? dawsoni Matthew MS. [1884]. ....--...---...----.--.-.------
Walcott: [1884artp mld Peprsceseeeeaeee eet ae ee
ineulardolataysardesony |blS96ss p90) |ey=setiei ee ee ees tae ee ae
imonilaratiexam oun Gruniehys [s'S 965s ee)! 4)| See see eee
Lingula ef. exunguis Gurich [1892, p. 69].............-.-.-.....-..-.-
Sremmmeolziet [MENG jo. QUE. oo scccccencsasesccosse

Lingula (?) favosa Linnarsson [1869a, pp. 356-357]. .--...--..----------
Iinnarsson [11869)b; p: 406]-=---------------_--.-

Lingula feistmanteli Barrande [1879b, Pls. CVI and CX]......--.------

Ibiroveqnlley Inia ROWAN. | = 52 os seccssoncsecaseesscesssee

Ihingula hawkei? Bornemann [1'891, p. 439]-----.----2----------.-.2.--
Lingula humillima Barrande [1868a, p. 101].............---...---.----

IsgnamCle |[IKOS]0), jo. WIL. = s = 2 sec eccceesssessco5
Lingula inchoans Barrande [1868a, p. 102].-.-.......-...--------------

Barrande [1868b, p. 692]. -

Lingula insons Barrande [1879b, Pl. CV, ae wee ae 6]. SRN Md pA Ey
line ulagolesBullings}|l8Goa), ys Zi pts eee eee es See eee eee

- Lingulella bellula.

Lingulella billingsiana.

-Lingulella grandis.

Obolus (Westonia) bottnicus.

- Lingulella lepis.

Do.
Lingulella cedens.
Do.

-Lingulella lepis.

Do.
Obolus cyane.

-Lingulella (Lingulepis) acuminata.

Do.
Lingulella davidsoni.
Lingulella davisi.
Do.
Obolus (Mickwitzella) siluricus.
Lingulella ferruginea.
Do.
Obolus dolatus.
Lingulella siemiradzkii.
Do.
Do.
Obolella (Glyptias) favosa.
Do.
Obolus feistmanteli.
Not taken up in this monograph; it does
not equal Mickwitzia sp. undt.
Mickwitzia sp. undt.
Lingulella? humillima.
Do.
Acrotreta inchoans.
Do.
Lingulella? insons.
Lingulella iole.

inne nlasinene Baullimes| (S620 pps el 72] sees eee ee eee Lingulella irene.
TBM, Ware aOllesassascaGecoonseousucssaudSsocgcuc Do.

ILpirarequilley eerie; Lehr htravess) (PINS), To). BO, 552 S45 segkcc cesses esses sees sees

Lingulella iris.

Lingula? kiurensis Waagen [1885a, pp. 768-769]. ..........---.----.--- Lingulella kiurensis.

Waagen [1891, Pl. II, figs. 17a—b]. -

Do.

Lingula lamellosa Barrande [1879b, Pl. CVI, figs. 1: ie 5 PL. “OXI, fen

Obolus (Westonia?) lamellosus.

Tingula? lens Matthew [190la, pp. 274-275]. ....-..--.-..--.-.--------- Lingulella lens.

Lingula? lepis Davidson [1866, p. 54]........-.-.---.----------------
Joniayerolley levers Seullixerr (MIS), Os GHs]|a 6 ass secasseacinosscocadsavaucenscee

Lingulella lepis.
Do.

SYNONYMIC REFERENCES. ait

Present reference.

Lingula? manticula Walcott [1884b, pp. 13-14].........----------- ...-Lingulella punctata.
Wihite [S74 pn9 0) saenes see eteeneer ener m= Lingulella arguta (in part) and L. manti-
cula (in part).
White [1877, pp. 52-53, Pl. III, fig. 2a].....-..-..-- Lingulella arguta. The text also includes
L. manticula.
Vivant’ |BRSir/s (Os BRA Jel, TUN, ie, Zo) 2 s2csesscscse .-Lingulella manticula. The text includes
L. arguta.
Lingula matthewi Hartt [1868 p. 644]..........--..---------------:- Acrothele matthewi.
Elantti i878; 644)]\. ees es seep ec uae ele Do.
artt][S oil, jor G44 = Bee aes te eee a reer eer re acree aay Do.
Lingula? miranda Barrande [1879b, Pl. OXI]......-......-..--.------- Obolus? mirandus.
Lingula? monilifera Linnarsson [1869a, p. 344]... .-.------------------ Mickwitzia monilifera.
Lingula monilifera Linnarsson [1869b, p. 398]....--.-..-------------- Do.
Ibiasl, mnepsiin, 1SeNNl [NESS Ts WARE coc ccssossccescoccssuscssuscaasdod Lingulella mosia.
ISLE USB, 110s WOZSMO bon. osscsodenousbascsueseseso= Do.
Stunclers(orey [IRS jo CEs anceseesccs sacbaodaconosoesasucs Do.
Lingula? ordovicensis Moberg and Segerberg [1906, p. 63]. ....--------- Lingulella lepis.
IL, CyANi2 1BimmenoRNs} [fils jo), WO Ea oneec oes scounosdecccsaugeseancs Lingulella prima.
McCoys [SAG p24 ean otis oases eee nase e eee aes Lingula ovata, not Lingulella davisi.
McCoys [MiSodmpe 204] ee 2 Ake oka ate se Ase elie Lingulella davisi (in part) and Lingula
ovata (in part).
Lingula petalon Bornemann [1891, p. 438]......-...---.--------------- Obolus? meneghinii.
Derpielsoin [UAT fo SOS] se oonosdssssacleccssdcosscosces Does not equal Obolus ? meneghinii.
IDanniclsom [USL Do SBW/]] occogeocsecces ao ancacesnsucccs Does not equal Obolus ? meneghinii.
Hingula; pinnaformis Owen! [18525 p, 683]---.--.22--2-.------.-------- Lingulella (Lingulepis) acuminata.
Lingula pinneeformis Hall [1862, p. 435, and fig. 3, p. 21)...........-.-- Do.
Ibriayenailley, Foros kniiey WSLeMNE SUSAN, To), ZA coc sesso sesegesedcscoosaeoscceesansce Dicellomus politus.
Lingula? polita Hall [1862, pp. 21 and 435]......-....--...---..------- Do.
ILtmaqolls, jolie, WWlamaakellel ([Y), jOs TBO] ose cascassacoasecdoocse-ccecu Do.
ILiuareqalley joxetioaes, Ter llhnaers) [USD Jon BH boe2-sacsascccssesscess5cscedacaccs Lingulella (Lingulepis) acuminata.
ISreavan orang [MED D> AVA. os o sas-ds0cagcosacccsoccucuccac Lingulella prima.
TaN i847 4p. 23ierie 8s seek se ejee seas Sees osee oe sees Do.
alls (Sol sp. 204 bae Weve see dota an ee occa seer Lingulella (Lingulepis) acuminata.
lalenrlern, EO. TOs WBllasosasaceoencaae vseccsdacecnueceas Probably equals Lingulella (Lingulepis)
acuminata.
Onens PSST ps WON Se ae ae ke 2 Be ere eae cet Seer Lingulella (Lingulepis) acuminata.
Rogersi[WS6L ip: 390] Pa sae soe e ages yee eee ee ee Obolus (Westonia) rogersi.
Lingula? producta Moberg and Segerberg [1906, p. 63]. .--..--.--.------ Lingulella lepis.
Tniniernlampyemnceas David sony [HlS6 65s) s103] seen see eee eee Lingulella (Lingulepis?) pygmeza.
Marilee QOD. pati Ai es Sis 2S aah se eee ee eae Do.
Philip sh [Slips GSi| Mss ass eee eracneee aoe Do.
Salter) (MSGS wos llO2| Re oan aos ees Bae Do.
Lingula roualti Bornemann [189il, p. 439]... ...--2..2.22-222.222---2. Kutorgina sardiniaensis.
Lingula? signata Barrande [1868a, p. 103]...........-.-.-..-.-...------ Lingulella signata.
Bamram cen |S 6S iore p92) eee eae ene Do.
Lingula simplex Barrande [1879b, Pl. CIV, figs. vi: 1-4]................-. Lingulella? simplex.
?Lingula squamosa Davidson [1866, p. 41]...................-.-.--.--..-.- Lingulella (Lingulepis?) squamosa.
Hineallaysquamosalerolll) (8 Gossjoel O2)] eee ee eee eee Do.
Lingula? warthi Waagen [1885a, pp. 769-770]............-.-.-.-.-.--.--- Lingulella kiurensis.
\W Weaver [RSL IPS IEE, mess, WER oooeaccoscos sscseccna 58 Do.
ihimgulagwinonay eal (8635p. d26)|Geeseee= ease =e sees aes eases Lingulella winona.
Vals [SG iyo all 2a Meese aa se a see ptueeay a ae Do.
SHG lesOm [USING 70. OG, scosesccdac as cacssbseeacdsesescese Do.
ingwilaswarthi Barrandel[il868a, p02 222222 ees se] eee Lingulella wirthi.
IBnermaels [UNTO 19> OY. oso ssoscnsscbocnssscor-scssess Do.
Ibis wl so), IDNs MSG, 0. WOl|ooosccesenscseoensaascasacsscouesesseouas Lingulella davisi.
Sedgwick [1847, pp. 140, 148, and 147].......................- Do.
liqtarsqaleey? Ryo ING. I \Wriaaenal OA, >, Bi bess se scecceqassacescassesoeseu-s Obolus (Westonia) wimani.
Nos 2 Wits OP, 1 )seceasascadacdocacsocoasdedcasene Obolus (Westonia) alandensis.
Lingula or Lingulella sp. Linnarsson [1876, pp. 15-16]..-................. Doubtfully equals Lingulella ferruginea.

» Lingula (Glossina) acuminataHa Il and Clarke [1892c, Pl. I, figs. 1 and 2]. -Lingulella (Lingulepis) acuminata sequens.

58 CAMBRIAN BRACHIOPODA.

Present reference.

Lingula (Lingulella) Oehlert, [1887, p. 1261]........-...-.-.-.-.------ Lingulella.

Lingula (Lingulella?) lepis Brogger [1882, p. 44]. ........--..-.---------- Lingulella lepis.
Lingula (Lingulella) lepis Davidson [1866, desc. of Pl. III]...-..-......-- Do.

Lingula (Lingulepis) Oehlert [1887, p. 1261]..........-.---.-..------------ Lingulella (Lingulepis).
lingulze-comes [Tellinomya], McCoy [185la, p. 56]....--.--.--.---------- Lingulella davisi.

RENUIGieus so er ee et Ae eee ee reco Sa NOR Does not equal Lingulella davisi.
lineuleeformis [Obolus (Leptembolon)], Mickwitz [1896, pp. 200-204] . . . .. Lingulella (Leptembolon) linguleeformis.
linguleeformis solidus [Obolus (Leptembolon)], Mickwitz [1896, pp. 204—

DVB Seb chia Soho ae 0 ee a RE Spee nee Do.
‘Lingulella Bornemann [1891, pp. 435-437]..............----------------- Lingulella.
IDM PISO), Gayo), Wass eum! W5)||. =. wos eesesecdsesocoaesssancneces Do.
Dall [8775 so 44] See at Seis Sane Sek spe e sets See Do._
Davidsous [S66 pyboleeeeer merase aaC een ace seas o eee Do.
Davidson! fl868 ps s04|Peeete2 Senet eis ecient secs ciice es Do.
Deloado) [MOO qos SGT rea aek ee ae cee ee sce eye cee Do.
7 Grabauand) Shimer [907s 192] beeen ee nee se eee ener Obolus (Westonia).
Hall and Clarke [1892a, pp. 232-233]...........-...-..-----4-- Lingulella (in part) and Botsfordia (in part)
Hall and Clarke [1892b, pp. 548-549]. -................--------- Lingulella.
Hall and Clarke [1892c, pp. 55-59]---.....----....-.----------- Lingulella (in part), Botsfordia (in part),
Obolus (Westonia) (in part), etc.
Mearttivewallill89 joss O18 seeeeeerse ee ease ere eae eee eae Lingulella.
Matthew [l902emprmlOSiI Mes seccen se ceatials Seen ee tamelacmetee Do.
Martine wr [el QO 33a spill Gi] Meters tyes) at-e teva eteins <aieie ee eveite antalya Do.
Meeks [8s ip sl S618 7a] Ae mse acres cs seit eiclevarageratereisieie ehapeeiore Do.
Salter, [il86Gbepgddalleeeseseesee eta erectoncee eee costes Do.
Salter and Etheridge [1881, p. 537]..........-...--.----------- Do.
Walcott [1908e, Pl. XI, and pp. 142 and 144].........-....--.- Do.
Fivtel PUSGOM pp. GOI GBA ieee Se Ac Ne een asec coe Do.
(Lingulella) [Lingula], Oehlert [1887, p. 1261]............-.--..........- Do.
(Lingulella) [Obolus], Walcott [1898b, pp. 390-392].............. emeemeeue Do.
Wrallkoorns [N@OI, jo. G88) bsseconastecencacesasdascauesee Do.
(Lingulella) acutangulus [Obolus], Walcott [1898b, pp. 393 and 394, Pls.
OQ Vaulenavell DOWNY PA ease Samise aaa eS eae eRe eso Esosdceosaacadoso Lingulella acutangula.
Lingulella? affinis Billings [1872b, p. 468]. ...........-..---.---.-------- Obolus (Lingulobolus) affinis.
Billings! S74 aipy Gi sesceceseseensscoe cme eesemese sees Do.
Lingulella affinis Billings [1882, pp. 15-16]. ....-.-....-..-..---..----- Do.
Lingulella ampla Schuchert [1897, p. 257].-....--...-----.------------.- Lingulella ampla.
(Lingulella) amplus [Obolus], Walcott [1898b, pp. 392 and 394, Pl. XX VIII] Do.
(Lingulella) argutus [Obolus] Walcott [1898b, p. 396]..-.....--.-.--.------ Lingulella arguta.
(Lingulella) atavus [Obolus], Walcott [1902, pp. 609-610]........--.-.--.- Lingulella atava.
(Lingulella) auga [Obolus], Walcott [1898b, pp. 396-397].........--.-.---- Lingulella auga.
Lingulella aurora Grabau and Shimer [1907, p. 193].-.-.....-..--.-------- Obolus (Westonia) aurora.
TBI PLY yoy ee Oa se ae be cS Do.
Hall and Clarke [1892c, Pl. II, figs. 12 and 13]..........-. Do.
Lingulella aurora var. Hall (1873, pp. 244-245]..............-.--.---.----- Obolus (Westonia) stoneanus.
(Lingulella) bellulus [Obolus], Matthew [1908, p. 205].......-.......-...-- Lingulella bellula.
\Wail@onis [SBE o, 1 Sisilcasscesteaseconcace Do.
(Lingulella) bellus [Obolus], Matthew [1903, p. 204]...........-..-.--..-- Lingulella bella.
Walcott [1898b, pp. 397-398]............-.-- Do.
Walcott [1901, pp. 685-687]..........-.-..-.-- Lingulella bella (in part), L. concinna (in
part), and L. lens (in part).
(Lingulella) bicensis [Obolus], Walcott [1901, p. 688].........-....-.-...-- Botsfordia ceelata.
Lingulella? billingsana Schuchert [1897, p. 256]............-..------.-.-- Lingulella grandis (in part) and L.
billingsiana (in part).
(Lingulella) bornemanni [Obolus], Walcott [1901, pp. 687-688]. ...-..------ Lingulella bornemanni.
Lingulella buttsi Walcott [1908d, pp. 70-71]..........-......-..---------- Lingulella buttsi.
Iineulellajcelata Ford! [S785 pp. 127—128]o.- 2.222 2222 oe eee ene eee Botsfordia ceelata.
Hall and Clarke [1892a, Pl. III, figs. 14). Sisto tie Pelee Do.
Hall and Clarke [1892c, pp. 57 andl Gis) Beane see eErae sos Do.
Walkcovis [MING O. Ds CB osceacesssaecosseteasecasscousenc Do.
Walcott [1887, p. 199, Pl. I, fig. 16]..-.--..-.---------- Do.
Walcott [Solas pHiGO 7x teeeisee nts sneer ye cio caren eee Do.

(Lingulella) canius [Obolus], Walcott [1902, pp. 610-611].........-..-...-- Lingulella cania.

SYNONYMIC REFERENCES. 59

Present reference.

(Lingulella) celatus [Obolus], Walcott [1898b, Pl. XX VI, figs. 1 and 2] ....Obolus (Schmidtia) celatus.

(Lingulella) chinensis [Obolus], Walcott [1905a, pp. 328-329].........-...-- Obolus chinensis.

(Lingulella) chuarensis [Obolus], Walcott [1898b, p. 399]....-----.-------- Obolus (Westonia) chuarensis.

lnmeuleliaiclarkel Walcott [mewless-eesseee ses eee eae ene see eee e Lingulella clarkei.

Lingulella? ccelata Matthew [1895a, p. 126]...-..-.:------------------- .. Botsfordia ceelata.

(Lingulella) collicia [Obolus], Walcott [1902, p. yee Pena syarctee ie esiecsuis Nes Lingulella collicia.

Lingulella concinna Matthew [1901a, pp. 273-274]... --1--------------Lingulella concinna.

Matthew [1903, pp. 203-204]. - Pes Perera ens e\ «aes Do.

(Lingulella) concinnus [Obolus], Walcott [1902, pp. - 608-609]. Bes eee wie ee Do.

Lingulella? cuneata Matthew [1894, pp. 92-93].-.....-....-..-.--..-.---- Lingulella grandis.

(Lingulella) cuneolus [Obolus], Walcott [1899, p. 443].............-.------ Lingulella cuneola.’ ;

(Lingulella) damesi [Obolus], Walcott [1905a, p. 329].......--.----------- Obolus damesi. (See Lingulella damesi,

p. 489.)

Lingulella davisi Davidson [1868, pp. 304 and 306]..........-..---------- Lingulella davisi.

Hall and Clarke [1892a, p. 232]..........--.------------- Do.

Hall and Clarke [1892b, p. 548]..........-.-.-..--------- Do.

Hall and Clarke [1892c, pp. 56 and 57].......-..---..---- Do.

Wieialke |LMEVALS fords MGW ||. co seadsecsanccasstsomoboeses4 Do.

Salter |[MSIHo, jolo, SEB=SBH | coecoessoosccosce>saeeonucone Do.

Lingulella davisii Davidson [1866, pp. 56 and 57].-.....-.....------------ Do.
Valle 873 Pl exenh fier4 |S ee teen ccs estes eels Do.

IRorermney |[Nei(G, I INL, ites, GE) oaconcaaocooscsceunesecs Do.
SalitersWS67quppe44 andito2] pases eeesee nest eeeee ene eee Do.

Salter and Etheridge [1881, pp. 537-538].....-..--- Saunas Do.

Iimeulella ef, davisii Kayser (1897, p. 280]----.--..------------+--------- Do.
Matthew [1902b, pp. 407-408]........-...----------- Do.

Wiener IGOR. foc AOS Loccconecsucdonesrandsudancce Do.

(Lingulella) davisii [Obolus], Walcott [1898b, pp. 394 and 395]...........- Do.

Lingulella dawsoni Hall and Clarke [1892c, p. 58].-........--.----------- Lingulella ferruginea.

Matthew [1886, pp. 33-34, Pl. V, figs. 9, 9a-c]........- Lingulella martinensis. The text includes
L. ferruginea. :
Matthew [1886, pp. 33-34, Pl. V, fig. 9d]........-....-- Lingulella ferruginea. The text includes
L. martinensis.
imeulella deleadoi Walcott [mew] 222-2 222..52.2--2-22 2252-2 -22e nee se Lingulella delgadoi.
(Lingulella) desideratus [Obolus], Walcott [1898b, pp. 399-400]........--..-. Lingulella desiderata.
Walcott [1899, pp. 445-446, Pl. LX, fig. 2]. - Do.
Walcott [1899, pp. 445-446, Pl. LX, :
HO Dasa oleiciz cj syeyslcle spa sieves siete eer Obolus rotundatus.

(Lingulella) diseoideus [Obolus], Walcott [1901, p. 673].-....-..---..---.--Obolus discoideus.

(Lingulella) dubius [Obolus], Walcott [1898b, p. 401]..-......---....-.--.-Lingulella dubia.

Lingulella ella Hail and Clarke [1892c, p. 58, figs. 19 and 21]........--....- Obolus (Westonia) ella. The text includes
also specimens representing Lingulella
dubia.

Hallvandi@larket [i892 paoomtice 20) esos eee eeeee eee Lingulella dubia.

Leb yoltel IGS 8 ona! ol eee ae mee ow AoE seer caee co oS eee Re Obolus (Westonia) ella.

Walcott [1886b, pp. 97-98, Pl. VII, fig. 2; Pl. VIII, figs. 4,

Aa AAC taioe we iets aah ee tse oe BOO ee Ee Obolus (Westonia) ella. The text includes

also specimens representing Lingulella
dubia. .

Walcott [1886b, pp. 97-98, Pl. VIII, figs. 4b-c]...........- Lingulella dubia. The text includes Obo-
lus (Westonia) ella.

Walcott [1891la, p. 607, Pl. LX VII, figs. 2c-d]............ Lingulella dubia. The text includes

Obolus (Westonia) ella.
Walcott [1891a, p. 607, Pl. LX VII, figs. 2, 2a-b, and 2e] ...-Obolus (Westonia) ella. The text includes
also specimens representing Lingulella

dubia.
(Lingulella) ella [Obolus], Walcott [1898b, Pl. XXVIII, figs. 5-8]......... Obolus (Westonia) ella.
(Lingulella) ellsi [Obolus], Walcott [1898b, p. 402] ..................-.-.- Lingulella ellsi.
Lingulella (?) escasoni Matthew [1901la, pp. 270-273]....................-- Obolus (Westonia) escasoni.
(Lingulella) euglyphus [Obolus], Walcott [1898b, pp. 402-403]. ..........- Obolus (Westonia) euglyphus.
Lingulella ? cf. Lingula favosa Matthew [1888, pp. 28-29]...............-..- Botsfordia pulchra.

Lingulella ferruginea Davidson [1868, pp. 306-307] ...............-.-...-- Lingulella ferruginea.

60 CAMBRIAN BRACHIOPODA.

Present reference.

Lingulella ferruginea Davidson [1871, pp. 336-337]...........-.-.-------- Lingulella ferruginea.
Davidson [1883, Pl. XVII, fig. 35]..................- Do.
Delgado [1904, pp. 368-369].....................-.- Lingulella delgadoi.
Matthew [1903, p. 108]... ee -------------Lingulella ferruginea.
Salter [Salter and Hides. 1867, Dp. 0). a ie ee Do.
Salter and Etheridge [1881, p. 538]-. Bates os oe Do.
Lingulella cf. ferruginea Kayser [1897, p. 280]..............-..-.--------- Do.
Lingulella ferruginea ovalis Davidson [1868, p. 307].............-..--.--- Do.
‘Hicks [Salter and Hicks, 1867, p. 341]........ Do.
(Lingulella) fragilis [Obolus], Walcott [1898b, p. 404]..................... Obolus fragilis.
(Lingulella) franklinensis [Obolus], Walcott [1898b, pp. 404-405] ......... Lingulella franklinensis.
Lingulella fuchsi Redlich [1899, p. 7]--....-........- LU ere op een Lingulella fuchsi.
(Lingulella) fuchsi [Obolus], Walcott [1905a, p. 332].....................-- Do.
(Lingulella) gemmulus [Obolus], Walcott [1901, p. 673]..................- Lingulella ferruginea.
ILtasauleikey exeyavert Levels [IGG 7). 225). .cccacescoscoseseacaseseeesesseqcecs Lingulella dubia.
Lingulella granvillensis Delgado [1904, pp. 367-368].....................--Lingulella delgadoi.
Hall and Clarke [1892c, p. 58]--.................. Lingulella granvillensis.
Oehlert [1889, p. 1138]. - eee eee Lit ores Do.
Walcott [1887, pp. 188-189] eter t ie ath ease O02 pa Do.
Walcott [1891a, pp. 607-608]..................... Do.
Lingulella cf. granvillensis Matthew [1895a, pp. 114-115]..................Lingulella martinensis.
Lingulella gregwa Matthew [1899b, pp. 199-200]. .....................--.- Lingulella (Lingulepis) gregwa.
(Lingulella) hayesi [Obolus], Walcott [1898b, pp. aoe cS ele Lingulella hayesi.
Lingulella heberti Barrois [1882, pp. 185-186]. . ---------------....--Lingulella heberti.
(Lingulella) helena [Obolus], Walcott [1898b, p. - 406]. See ee eee nl ellashelenss
Lingulella? inflata Matthew [1886, p. 33]...........................-.---- Acrotreta inflata.
Wiemilneny [MECH 19. U2loscoacsnce ssocacesseesccosnocce Do.
Wierda [USER To. WS] oecocosccoessasosaseuasscascus Do.
Lingulella? inflata ovalis Matthew [1895a, p. 127]......-..............-.-.- Do.
(Lingulella) ino [Obolus], Walcott [1898b, pp. 406-407]....................Lingulella ino.
fimemlellapimen ess cbrichents pS Oi/em se.) | Seen Lingulella irene.
(Lingulella) isse [Obolus], Walcott [1905a, p. 330] .......................- Lingulella isse.
Lingulella levis Matthew (1892, p. 39] .................-......------.------ Lingulella levis.
Lingulella levis grandis Matthew [1903, pp. 200-201] ....................- Lingulella levis grandis.
Lingulella levis lens Matthew [1903, pp. 201-203] ......................-.- Lingulella lens.
Lingulella lamborni Keyes [1894, pp. 38-39].............- drapes Senet Rao Obolus lamborni.
Lingulella? lamborni Meek [1871, pp: 185-187] .....-- Soe oa eS e eRe IS ee Do.
(Lingulella) lamborni minimus [Obolus], Walcott [1898b, p. 407].........-- Obolus lamborni minimus.
Lingulella lens Matthew [1903, pp. 205-206]...........:............-....- Lingulella lens.
(Lingulella) lens [Obolus], Walcott [1902, pp. 606-607].................... Do.
(Lingulella) leos [Obolus], Walcott [1898b, pp. 407-408].................-- Lingulella leos.
Lingulella lepis Davidson [1868, pp. 307-308]..............-...-.....---- Lingulella lepis.
Davidson [1871, Pl. XLIX, figs. 31 and 3la]............... Do.
Efolim![1SO8t pulses ues sm sac os ees et ee eee Do.
Moberg and Segerberg [1906, pp. 62-63]............-...-- Do.
Salter; [S66 bw usS4] eae eee ee ee i) eee eee een Do.
Salter and Htheridge [1881, p. 538]-....-.........-..-.... Do.
Lingulella lepis? Westergard [1909, p. 57]_.-.------..-.--.....-.-.....-.-- Do.
Wiener (IGO2, joo, (88 ainel Vlocsessdecesbscsoedsseenecen Do.
Lingulella cf. lepis Matthew [1903, p. 204]..........................-..-.. Do.
(Lingulella) lepis [Lingula], Davidson [1866, desc. of Pl. III]............. Do.
(Lingulella?) lepis [Lingula], Brégger [1882, p. 44]......................- Do.
(Lingulella) lineolatus [Obolus], Walcott [1898b, pp. 408-409]...........-- Lingulella lineolata.
Lingulella linguloides Matthew [1886, p. 34]..........................-.-- Lingulella ferruginea.
Lingulella cf. linguloides Delgado [1904, pp. 369-370]................-.-- Lingulella delgadoi.
(Eingulella) linnarssoni [Obolus], Walcott [1901, p. 688]. .............-... Lingulella linnarssoni.
Lingulella longovalis Matthew [1903, pp. 123-125] .......-...-....-..----- Lingulella triparilis.
Lingulella mceconnelli Matthew [1902c, p. 108]...........-.-.-.-------.-- Obolus meconnelli.
Well@onsis (INE, Tos CSM [oe sec eb acto susaseeboGeocass Do.
Linguella? mera Hall and Clarke [1892c, p. 61] ........---.-......---.--- Obolus meera.
Walcott [89 farnn y404) ie ee ve. clay eae eee Do.

(Lingulella) mzera [Obolus], Walcott [1899, p. 443] ...-.-.-----..-.-------- Do.

SYNONYMIC REFERENCES.

Lingulella martinensis Matthew [1890, pp. 155-156].......-.--.------.----
Martti ew [MSO aarp poy lili 104) | Besar epee eret fee)

Lingulella? matinalis Walcott [1897a, p. 404] ........-..------------------
(Lingulella) matinalis [Obolus], Walcott [1899, p. 443].......-.----------
Lingulella minuta Schuchert [1897, p. 257].......-.-.-------------------
(Lingulella) mosia osceola [Obolus], Walcott [1898b, p. 409].---------------
(Lingulella) nanno [Obolus], Walcott [1898b, p. 409] ..--------------------
Lingulella? nathorsti Linnarsson [1876, pp. 15-16].....-....--------------
Lingulella nicholsoni Callaway [1874, p. 196]..-....----------------------
Callaway [1877, pp: 668-669]-=-2222.222-5--2-.-----

Davidson’ [1883, pp. 208-209]------------------ =...

Lingulella nicholsoni? Matley [1902, p. 141]........---..---.---.----------
(Lingulella) orus [Obolus], Walcott [1905a, p. 330]...-...------------------
(Lingulella) oweni [Obolus], Walcott [1898b, p. 410]...---..--..-------.--
(Lingulella) pelias [Obolus], Walcott [1905a, pp. 330-331]. --.--
(Lingulella) perattenuatus [Obolus], Walcott [1899, p. 443].--..------------
(Lingulella) phaon [Obolus], Walcott [1898b, pp. 410-411] .---......--.---
(Lingulella) pogonipensis [Obolus], Walcott [1898b, pp. rere: Lacs wee
Lingulella? prima Hall and Clarke [1892c, p. 69].-.-.----.--------:--------
Lingulella primzeva Davidson [1883, p. 208].....-...-.------.------------

ieks [1s7l ps 40l Me mceeee ses see Saye Sewers
Hicks: [a S8il sp. 297 paseo cera coe eene sears a

Salter and Etheridge [1881, p. 538]..-.-..--

(Lingulella) prindlei [Obolus], Walcott [1898b, p. 412].-.........-...-----

(Lingulella) punctatus [Obolus], Walcott [1898b, pp. 412-413].

(Lingulella) quadrilateralis [Obolus], Walcott [1905a, p. 331]..........----

Lingulella radula Matthew [1891, pp. 147-148].-..--.-..----.--

Lingulella radula aspera Matthew [1903, pp. 204-205]...--..---

(Lingulella) randomensis [Obolus], Walcott [1901, pp. 688-689]..........--
Lingulella roberti Matthew [1895b, pp. 256-257]........-...---
Lingulella rogersi Grabau [1900, pp. 624-625]..-......-...-----
(Lingulella) rogersi [Obolus], Walcott [1898b, pp. 4183-415]... - -

(Lingulella) rotundatus [Obolus], Walcott [1898b, p. 415] --...-
(Lingulella) schmalenseei [Obolus], Walcott [1902, p. 605]. .---
(Lingulella) schucherti [Obolus], Walcott [1901, pp. 689-690]. -

Lingulella selwyni Matthew [1895b, pp. 255-256]............-....--.------
Weary |[MOOS, joos O2—Cil|-sasaseoscosasasssscecso5aces
Weiner |M0s, joo. WIGS. soccsccecsosecaaeanescase

Tingulella) septalis [Obolus], Walcott [1905a, p. 331].-.-------
8 p

(Lingulella) siemiradzlai [Obolus], Walcott [1901, pp. 699-691]

(Lingulella) similis [Obolus], Walcott [1898b, pp. 415-416].........-.-...-

(Lingulella) sinoe [Obolus], Walcott [1898b, pp. 416-417]......-...--..-.-
(Lingulella) spatulus [Obolus], Walcott [1902, p. 607].........-.--.-------
Lingulella? spissa Billings [1872b, pp. 468-469]......-...---..-.--.-------
loi Nbnaterss [IReVAl jojo. OVHGSl|- bso + seuacassooscesenosccase

Billimoss S82 eel 5| Moseee ee sere eee per eee etree meet

Lingulella starri Matthew [1891, pp. 146-147]...........-..--..--..--..--
Lingulella starri minor Matthew [1892, pp. 58-59]-....-.....-..---.-------
Lingulella stoneana Hall and Clarke [1892c, Pl. II, figs. 9-11]......-......
‘Weller: [903 sspears ie Se eel eee oe ce eee eee

Whitfield [1882, pp. 344-345]...-..............--...--

(Lingulella) tarpa [Obolus], Walcott [1898b, pp. 417-418].........-.------

Present reference.

Lingulella martinensis.

Do.
Obolus matinalis.

Do.
Linnarssonella minuta.
Lingulella mosia osceola.
Lingulella nanno.
Lingulella nathorsti.

- Lingulella nicholsoni.

Do.

Do.

Do.
Lingulella ora.
Lingulella oweni.
Obolus mcconnelli pelias.
Lingulella perattenuata.
Lingulella phaon.
Lingulella pogonipensis.
Lingulella prima.
Lingulella? primeeva.

Do.

Do.

Do.
Obolus prindlei.
Lingulella punctata.
Lingulella quadrilateralis.
Lingulella radula.

Do.

- Lingulella randomensis.

Lingulella (Lingulepis) roberti.
Obolus (Westonia) rogersi.
Do.
Obolus rotundatus.
Obolus schmalenseei.
Lingulella schucherti.
Obolus selwyni.
Do.
Do.
Obolus septalis.
Lingulella siemiradzkii.
Lingulella similis.
Obolus sinoe.

Lingulella (Lingulepis) spatula.
-Obolus (Lingulobolus) spissus.

Do.
Do.
Lingulella (Lingulepis) starri.
Lingulella minor.
Obolus (Westonia) stoneanus.
Do.
Do.
Lingulella tarpa.

boil, jie, Wealloot [WOE TOs Wiles ss5e2 eee esos et seeaessssesscene Lingulella texana.

Lingulella tumida Matthew [1899b, p. 200].-..........---..-.-.-.--------

Wien gleny [COR os IAB cces see csoasocsuesonecdasadess
Lingulella unguiculus Salter [1866a, p. 285].........-.....-..--.---.------
(Lingulella) upis [Obolus], Walcott [1905a, pp. 331-332].............-..---
Lingulella wanniecki Redlich [1899, p. 7].....---.---.-:-----------------
(Lingulella) wanniecki [Obolus], Walcott [1905a, p. 332].......-...-.-..---
(Lingulella) welleri [Obolus], Walcott [1902, p. 608].......--.......--.-...
-Obolus willisi.

(Lingulella) willisi [Obolus]}, Walcott [1898b, pp. 418-419]...........-...-
Lingulella winona Schuchert [1897, p. 258]........---.--..-------.---.-- Lingulella winona.

(Lingulella) winona convexus [Obolus], Walcott [1901, p. 691]

Lingulella tumida.
Do.

Lingulella ferruginea.

Lingulella upis.

Lingulella wanniecki.
Do.

Lingulella welleri.

Bbc mieite Matsa ec Lingulella winona convexa.

61

62 CAMBRIAN BRACHIOPODA.

(Lingulella) zetus [Obolus], Walcott [1898b, p. 419]..-..-----------------
Pimewlellajzeus) Walcott) (Mew sss eeeeeeeteeee see eeee eee. -e see oe
iimeulellaisp: Kayser) [il S83 ipsa Sseeeeee se eeee arene ereeee eee eeeeee

Kayser [1/883 ipp como Gle sates eo cee me rise oes
Lingulella sp. [Lingula or], Linnarsson [1876, pp. 15-16]. .-..--..---.--
Lingulella sp. undt. Linnarsson [1879, p. 25]...-...-.--..--------------
Lingulella (?) sp. Pompeckj [1896b, p. 509]............-..--.---------
Lingulella? sp. No. 1 Wiman [1902, p. 52].....-...---...-.-------------

Lingulella? sp. No. 2 Wiman [1902, p. 52]...........-.-..-..---.-------
Lingulella? sp. No. 3 Wiman (1902, p. 52]..-..-...-..--....------------
Lingulella? sp. No. 4 Wiman (1902, p. 52]...-.......-...-----2---------
Lingulella? sp. No. 5 Wiman [1902 p: 52]........--.-....-..------.----

Lingulella? sp. No. 6 Wiman [1902, p. 52]............-...-...-----.----
Lingulella? sp. No. 7 Wiman [1902, p. 52].-.....--..-....!...-.--....--
Lingulella (Acrothyra?) inflata Matthew [1902b, p. 390]...-.-...--..----
Lingulella (Lingulepis) Walcott [1908e, Pl. XI and pp. 142 and 144]......
Lingulella (Lingulepis) acuminata sequens Walcott [1908d, p. 72]...--.-
Lingulella (Westonia) ella Grabau and Shimer [1907, p. 193]-..-.---.--.--
Lingulepis Dall [1870, pp. 154 and 161].-..............--.--.-..-------
Grabau and Shimer [1907, p. 193].......----.--.-------------

Ball) [(U863; spr M20 |e ts. sacs ieee ecient cee as ae ncee

Lal 867-5 OG Pees see se esc seas ars eee aaa

Hall and Clarke [1892a, pp. 231-232]..............--.---.---

Hall and Clarke [1892b, pp. 547-548]..........-....--...----

Hall and Clarke [1892c, pp. 59-62, and 164]...-.....-.......-

Matthew [ll902 cio elO2]seeaseee ie eee essere ier

Marthe wall003%ip 26) eeeseeeeaeoe cea y anes eee eee

Meek [1871 spp: 186-187] secees oiac sees Oaee ce ea cose Sh eses

Meek and Hayden [1865, pp: 1 and 2]..........-....--...---.--

Sarees (MII Is el Eeocooscudasnoscemeoeberedssesuebac
Walecottifls9/ia-yp 4 04! Peere eet riser sec ese eee

ZAtte [USS Op HOG aeaiser ae oases erasers oe cieia tee eee
(Lingulepis) [Lingula], Oehlert [1887, p. 1261].......-----...-.--------
(Lingulepis) [Lingulella], Walcott [1908e, Pl. XI, and pp. 142 and 144]... .
(Lingulepis) [Obolus], Walcott [1899, pp. 443-444]....................--
Walcott [1901 p. 683].--.------.-------- eerie!

Lingulepis acuminata Dwight [1886, p. 208]. ....-...-.--.--------.----
Matthew [1895b, pp. 257-258]. ........--.-----.--

sxolmucelaverny [ENO 19), 28) sccossancounecncsosanssac

Wailecott) [89 7atsp4404] a sasese)-eeseeeereeaas oeeiee

Lingulepis acuminata meeki Delgado [1904, pp. 366-367]....:.-......--
(Lingulepis) acuminata sequens [Lingulella], Walcott [1908d, p. 72]... .-

(Lingulepis) acuminatus [Obolus], Walcott [1899, p. 443].........------
(Lingulepis) acuminatus meeki [Obolus], Walcott [1899, p. 444]..........
Lingulepis acutangulus Schuchert [1897, p. 259]. -.....-...------------
Lingulepis affinis Walcott [1889a, p. 381]...........-......-.-----------
Lingulepis cuneolus Schuchert [1897, p. 259]...........---..---.---.--
Wihitheld | ilSi7eipps S=Olleseseacseseeere sea aea see

(WMA! MRCOL foe RA ena se Shee ec os medens-coone one

Lingulepis ella Hall and Whitfield [1877, p. 232]...........-----.------
Walcott: [MS97aspr404] ee sat eee eet ee eects

(Lingulepis) eros [Obolus], Walcott [1905a, p. 333]..-........--.--------
Lingulepis gregwa Matthew [1903, pp. 56-57, and 126-131].............--
(Lingulepis) gregwa [Obolus], Walcott [1901, pp. 692-694]..........-..--

Lingulepis gregwa robusta Matthew [1903, pp. 57 and 131]..............-
Lingulepis longinervis Matthew [1903, pp. 133-135]..........--..--..----
Lingulepis lusitanica Delgado [1904, pp. 365-366].........--..----.----
Lingulepis mzera Hall and Whitfield [1877, p. 206] ........-.-.-.-.--+----
Weenie [UNS joiO, IS. coae cose cusseescscoucccee

_ Lingulepis matinalis Hall [1863, p. 130]...........--...-..----.----.---
; Ea IM IS67Ampe LOT eee Aenea gaa ousecieee atta

as Do.
.-Lingulella (Lingulepis) acuminata.
4g Do.

Present reference.
Obolus zetus.
Lingulella zeus.
Obolus? sp. undt. f.
Lingulella davisi.
Doubttully referred to Lingulella ferruginea.
Lingulella ferruginea.
Lingulella cf. ferruginea.
Obolus (Westonia) wimani.

Do.

Obolus (Westonia) alandensis.
Obolus (Westonia) balticus.
Obolus (Westonia) alandensis.
Obolus (Westonia) balticus.
Obolus (Westonia) wimani.
Acrotreta inflata.

.-Lingulella (Lingulepis).

Lingulella (Lingulepis) acuminata sequens.

-Obolus (Westonia) ella.

Lingulella (Lingulepis).
Do.
Do.

ae Do.

Do.
Do.
Do.
Do.
Do.
Do.
Do.
Do.
Do.
Do.
Do.
Do.
Do.

ae Do.
.-Lingulella delgadoi.
.-Lingulella (Lingulepis) acuminata se-

quens.

.-Lingulella (Lingulepis) acuminata.
.-Lingulella (Lingulepis) acuminata meeki.
.-Lingulella acutangula.

--Obolus (Lingulobolus) affinis.
.-Lingulella perattenuata (in part).
.-Lingulella cuneola.

ae Do. \

. -Obolus (Westonia) ella.

ae Do.

.-Lingulella (Lingulepis) eros.

.-Lingulella (Lingulepis) gregwa.
..Lingulella atayva (in part), L. tumida (in

part), L. cania (in part), L. (Lingulepis).
gregwa (in part), and L. (L.) exigua.

. -Lingulella (Lingulepis) gregwa robusta.
.- Lingulella (Lingulepis) longinervis.
. -Delgadella lusitanica.

-Obolus mera.

ah Do.
.-Obolus matinalis.
Ee Do.

SYNONYMIC REFERENCES. 63

Lingulepis meeki Walcott [1897a, p. 405]...--..----..--..--------------
Lingulepis minima Dwight [1886, p. 208].........-..--..--------------
Wlnisfiallél [MISS fo, WAil])..cccacooandocacccseosnsoecee
Lingulepis? minuta Hall and Whitfield [1877, pp. 206-207]. .....-.------
Walkera nis |WESKYoy, 19}, WS} |sSacoconnoosegedocssnescasuane
Lingulepis perattenuatus Whitfield [1877, p. 9]......--..----------------

Whitfield [1880, p. 337]--

Lingulepis pinnaformis Hall [1863, pp. 129-130, Pl. VI, Baa, 2 sind 13] ack
Hall [1863, pp. 129-130, Pl. VI, figs. 14-16] -..--

Hall [1867, p. 107, Pl. I, figs. 12 and 13] .......-.

Hall [1867, p. 107, Pl. I, figs. 14-16] ..........-

Weloniiinelll ([IGO), 39), BHD] oc oesccsccocusoececce

Whitfield [1882, pp. 169-170] .........-.------

Lingulepis pinniformis Dwight [1886, p. 208]..........-..-------------
Grabau and Shimer [1907, p. 193].-..------.-----

Hall and Clarke [1892a, p. 282]....--..-----------

Hall and Clarke [1892b, p. 548]..-.....-..------

Hall and Clarke [1892c, p. 60]. -..-.-.---.------

Meek and Hayden [1865, pp. 2-3] ..-.------.---

Selameavern (IN, Ds ACD )|-nccacssccconsasocsnsqcesen

Lingulepis prima Grabau and Shimer [1907, p. 193]..--..-.-------------
Meek and Hayden [1865, p. 3]-..--..----..-----------

Miller) RS fe wpe Lib] eet ook ae ae annemnee eats

Selineliverat [MW, 1s WA esesesaccacecoscsacsaceesence

(isenlenis) primus [Obolus], Walcott [1901, p. 673]...-..---.----------
Lingulepis pumila Matthew [1903, p. 75]..-..-.-.-------.--------------
Lingulepis roberti Matthew [1903, p. 132].........--..---------+------
Lingulepis rotunda Matthew [1903, p. 199]. ...-...---.----.-----------
(Lingulepis) rowei [Obolus], Walcott [1905a, p. 334].......--.--..---..--
Lingulepis starri Matthew [1908, p. 195]....-...-...--..----------------
Lingulepis starri exigua Matthew [1903, pp. 197-198].-...---.-.--.------
Lingulepis starri var. Matthew [1903, pp. 193-197].............---------
(Lingulepis) sp. undt. [Obolus], Walcott [1906, pp. 567-568].--....-..--
lingulicomes [Tellinomya], McCoy [1854, p. 274].....-.-.-...-.--------
Lingulobolus Matthew [1895b, pp. 260-261]..........--..--..--+---------
(Lingulobolus) [Obolus], Walcott [1901, p.683]...........-.--.--.------
Walcott [1908e, Pl. XI, and pp. 142 and 144]....-

Lingulobolus affinis Grabau [1900, pp. 621-622].....-.....--..---.------
Matthew [1895b, pp. 261-262]. .....-...-......----

(Lingulobolus) affinis [Obolus], Walcott [1898a, p. 327]...-...-.-..--------
Lingulobolus affinis cuneata Matthew [1895b, p. 262].....-......---..-..-
(Lingulobolus) spissus [Obolus], Walcott [1898a, p. 327]. .-.....--------
linguloides [Davidsonella], Waagen [1885a, pp. 764-766]......-...--...-
linguloides [Lakhmina], Frech [1897, Pl. IA, figs. 4a-b]...-..----...------
Hall and Clarke [1892a, p. 234].........-......-

Hall and Clarke [1892b, p. 550]..-..--..----..----

Hall and Clarke [1892c, p. 28].....-..-...--..--

Ognilert (ME, foo WAS cecucccosncoeoeceuceocs

Waagen [1891, Pl. II, figs. 3 and 4] ..-.-.......

linguloides [Leptobolus], Matthew [1902b, p. 407]...---..-..---.--------
Martie wa [903 hip sl9Seasaseeeeeeeeeenreeeee

linguloides [Leptobolus cf.], Matthew [1902b, p. 407]....-..........---.----
Matthew [1903, pp. 192-193].--...-..-.---.-

linguloides [Lingulella], Matthew [1886, p. 34].-....--..-..-...---------
linguloides [Lingulella cf.], Delgado [1904, pp. 369-370]. .......--..----
Linnarssonella Walcott [1902, pp. 601-602]...-.....--..-.--.------------
Walcott [19C8e, Pl. XI, and pp. 142 and 146].....-....--
Linnarssonella broadheadi Walcott [1902, p. 601].....-...---.---..-------
Linnarssonella girtyi Walcott [1902, pp. 602-603]...........-.-..--.-------
Linnarssonella minuta Walcott [1902, pp. 603-604]................-...-.-
Linnarssonella modesta Walcott [1908d, pp. 90-91]....-..--..--..---.--
Linnarssonella nitens Walcott [1908d, p. 91].--..-.-..--.---------------
Linnarssonella tennesseensis Walcott [1902, pp. 604-605].-........----.-
Linnarssonella transversa Walcott [1908d, p. 92].-..-..-.-.--.---------

Present reference.

Lingulella (Lingulepis) acuminata mecki.
Lingulella (Lingulepis) acuminata.

Do.
Linnarssonella minuta.
Linnarssonella minuta (in part).
Lingulella perattenuata.

Do.
Obolus matinalis.
Lingulella (Lingulepis) acuminata.
Obolus matinalis.

- Lingulella (Lingulepis) acuminata.

Do.

Do.

Do.

Do.

Do.

Do.

Do.

Do.

Do.

Do.
Dicellomus politus.
Lingulella prima.
Lingulella prima (in part).
Lingulella prima.
Lingulella (Lingulepis) pumila.
Lingulella (Lingulepis) roberti.
Lingulella rotunda.
Lingulella (Lingulepis) rowei.
Lingulella (Lingulepis) starri.
Lingulella (Lingulepis) exigua.

Do.
Lingulella (Lingulepis) sp. undt.
Lingulella davisi.
Obolus (Lingulobolus).

Do.

Do.
Obolus (Lingulobolus) affinis,

Do.

Do.

Do.
Obolus (Linguloboius) spissus.
Neobolus warthi.

Do.

Do.

Do.

Do.

a Do.

Do.
Lingulella ferruginea.
Do.

Do.
Lingulella delgadoi.
Linnarssonella.

Do.

- Linnarssonella girtyi.

Do.

. Linnarssonella minuta.

Linnarssonella modesta.
Linnarssonella nitens.
Linnarssonella tennesseensis.
Linnarssonella transversa.

64 CAMBRIAN BRACHIOPODA.

Present reference.

Linnarssonella urania Walcott [1908d, pp. 92-93]...-..--.----------------- Linnarssonella urania.
linnarssoni [Obolus (Lingulella)], Walcott [1901, p. 688].........------.-- Lingulella linnarssoni.
linnarssoni [Orthis], Kayser [1883, p. 34]...-......-.......--..------.---- Eoorthis linnarssoni.
linnarssoni [Orthis (Plectorthis)], Walcott [| 905a, p. 266].........--...-.-- Do.
Linnarssonia Dawson [1890, pp. 53-54]..............-..------------------ Acrotreta.
Grabau and) Shimer [1907 pp: 200)22 5-225 2255---.--- 22 Hither Acrotreta or Acrothele. (Seep. 631.)
Halland Clarke [1892a, p. 251]..............--...-----.----- Acrotreta.
IELeVbL eyovel Cllewaice |[MEWPO. 19), W8|as-s nee conceos ees cesse-e-55c- Do.
Hall and Clarke [1892c, pp. 107 and 109].........-...-.--..-- Do.
Matthewalli886 rors eeemenesecemeeete semen seer one ee Do.
Matthew) [892s ps 432i teaeeeea: --ssecemnsceemee ce so amceciieae Do.
Walcott [188has pois Peaancee sa-eceeeace sees ec erea eee Do.
Linnarssonia belti Matley (1902, p. 145].......-......----......--.-.----- Acrotreta belti.
Linnarssonia belti? Matthew [1892, pp. 42-43].............-.-----......- (?) This species is not specifically referred

in this monograph; it does not belong
with Acrotreta belti.
Linnarssonia cf. belti Matthew [1903, pp. 209-210]. ...........--.....---- (?) This species is not specifically referred
in this monograph; it does not belong
with Acrotreta belti.
Linnarssonia belti magna Matthew [1897b, pp. 169-170]............-..---- Acrotreta sagittalis magna.

Linnarssonia misera Hall and Clarke [1892c, pp. 108-109].............---- Acrotreta misera.
Matthew [1886, pp. 35-36]....-..-....---....-------- Do.
LLinnarssonia? nitida Walcott [1901, p. 673]...-..--...----------:--------- Acrothele nitida.
Linnarssonia pretiosa Grabau and Shimer [1907, p. 200]......-..--...-.---- Hither Acrotreta sagittalis or Acrothele pre-
tiosa. (See p. 652.)
Hall and Clarke [1892c, p. 70]-.--..:.-------------- Acrotreta sagittalis. ‘
srelmucolavera’ [WEE JO, All oaaacasccassdaseesecoszess Acrotreta sagittalis (in part) and Acrothele
pretiosa (in part).
Welleots [IGOIL, jo, GrBllssceocsscsonseaccsocdescaseunoe Acrothele pretiosa.
Linnarssonia cf. pretiosa Hall [1890, p. 55].-........--.----------.--------- Acrotreta sagittalis.
(Linnarssonia) pretiosa [Obolella], Dawson [1890, pp. 53-54]........-.....-- Do.
Linnarssonia sagittalis Frech [1897, Pl. 1A, fig. 3a].............----...--- Do.
Hall and Clarke [1892c, p. 108].......-...---....--- Do.
Walcott ilSS5a-mp sellin) sasesee te sees seen eee Do.
Walcott [i889 emp m44o) eae oe ae jee ee ee ese Acrotreta depressa.
Walcott [1891a, Pl. LX VIII, figs. 2a-d]...........- Acrotreta sagittalis.
Linnarssonia sagittalis taconica Walcott [1889b, p. 36]..........-----..--- Acrotreta sagittalis taconica.
Walcott [1891la, pp. 610-611]. ......-..-...- Do.
Linnarssonia sagittalis transversa Frech [1897, Pl. IA, fig. 3b].-...-...---- Acrotreta sagittalis transversa.
Walcott [1891a, desc. of Pl. LX VIII, figs.
2a 262i] aeons tlt eee eee ee See Do
Linnarssonia taconica Oehlert [1889, p. 1188]. .-...........---..--.---.-- Acrotreta sagittalis taconica.
Wakeouit |MISS7, i705 WEOAGO)|52 56 sesneaaccseccsscu> Do.
Linnarssonia transversa Hall and Clarke [1892a, Pl. III, figs. 22 and 23]... .Acrotreta sagittalis transversa.
Hall and Clarke [1892c, p. Ree seb aeec sae a eee Do.
Matthew [1886, p. 35].- Berne ce Se eee ee Do.
Matthew [1895a, p. 125]... Ee See cay eth Sivas areata oe Do.
Wralkeoris |USHI, 1O> WMS possesses ocsobaccaccnessoce Do.
logany [iphideall) Walcott [1897b} pps 7712) Se se sees sees ee eases ese eee Micromitra (Paterina) logani.
longinervis [Lingulepis], Matthew [1903, pp. 133-135]. ...-...--..--..---- Lingulella (Lingulepis) longineryis.
longovalis [Lingulella], Matthew [1903, pp. 123-125]...-...........----.-- Lingulella triparilis.
longus [Obolus (Palzeobolus) lens], Matthew [1903, pp. 146-147]-.....-.-.--- Obolus (Palzeobolus) bretonensis lens.
longus [Obolus (Schmidtia) obtusus], Mickwitz [1896, pp. 171-172]----...-- Obolus (Schmidtia) obtusus.
loperi [Obolus], Walcott [1898b, pp. 389-390]. .....-...-.--.-.----------- Obolus loperi.
(Loperia) [Protorthis], Walcott [1905a, p. 287].-...-....------..---------- Protorthis (Loperia).
Walcott [1908e, Pl. XI, and pp. 142 and 147]....-... Do. .
(Loperia) dougaldensis [ Protorthis], Walcott [1905a, pp. 287—288].....--.---- Protorthis (Loperia) dugaldensis.
louise [Micromitra (Iphidella)], Walcott [1908d, pp. 56-57]....-- ices wate Micromitra (Iphidella) louise.
lowi (Nisusia Jamesella), Walcott [1908d, p. 98]--..-...--.---.----.------ Nisusia (Jamesella) lowi.
(Lucina) antiquissimus [Obolus], Eichwald [1843b, pp. 142-144]........-- Obolus (Acritis) antiquissimus.
lusitanica [Lingulepis], Delgado [1904, pp. 365-366]........--..---.------ Delgadella lusitanica.
lyncioides [Orthis lenticularis], Matthew [1892, p. 49]......-...---..----- Orusia lenticularis lyncioides.
Mattie wall 19035 sps 216] seeeees sees ae Do.

lyncioides [Orthis (Orusia) lenticularis], Walcott [1905a, p. 277]--.---..---- Do.

SYNONYMIC REFERENCES. 65

M.
Present reference.
mceconnelli [Lingulella], Matthew [1902c, p. 108]...........-..-.-------Obolus mcconnelli.
Walcott) [1889 cee alee eee ee eae Do.
meconnelli [Obolus], Walcott [1908c, Pl. I, fig. 2].....--.-.----.--------- Do.
Weallcoyi | COste, JPL, 1, tile AY oo 2a so cacecdoasbeauese Obolus septalis.
meconnelli decipiens [Obolus], Walcott [new].-..-..-.-..+.------------ Obolus mcconnelli decipiens.
macra [Nisusia (Jamesella) perpasta], Walcott [1905a, p. 255]...-..--..-- Nisusia (Jamesella) perpasta macra.
macra [Orthis perpasta], Pompeckj [1896b, p. 516].....----------------- Do.
maculata [Obolella], Davidson [1868, p. 311]. ..-.--.--.----------------- Acrothele maculata.
Denilson (VAL, 9s SH. a oc2osesccaccessansesooasee Do.
Welsadoy [904 or 364) Berea ae eee ee Acrothele villaboimensis.
Saltiers[1866a.ps 1285] 22 eee ee eee tere ween ae ae Acrothele maculata.
mera [Lingulella?], Hall and Clarke [1892c, p. 61]...-....-.....-...--:- Obolus mera.
Wallcotty [SO i7ert 1404: serene eee ee ee Do.
mera [Lingulepis], Hall and Whitfield [1877, p. 206]......-.-..-.------ Do.
Wearlkooris |B 4o), jojo, WARIB |. 5 os oac coceaccouseosaeeac Do.
mera [Obolus (Lingulella)], Walcott [1899, p. 443]........-..-.--....-.-. Do.
magna [Acrotreta sagittalis], Walcott [1902, pp. 595-596]....-.....-.-.---- Acrotreta sagittalis magna.
magna [Linnarssonia belti], Matthew [1897b, pp. 169-170]..............- Do.
major [Billingsella], Walcott [1905a, p. 239].....-....-.--.--.----.--.--- Billingsella major.
Walkeort (MOOR6E 195 NOMS ssa sscscescsuabscesoeses Do. :
mayomiphidella| Walcout)[1905a. ps 04] Nee se. sees cee see eos essere Micromitra (Paterina) major (in part) and
M. (P.) williardi (in part).
Bre ORV Ckaymbzi a2) peMiLeKewiltz, [896% pon 23\ lessees oa eee eee Rustella? major.
major [Obolus?], Matthew (1890, p. 155]...-.-..--......-...........--.- Do.
maladensis [Iphidella pannula], Walcott [1905a, p. 306]. ..............-.- Micromitra (Iphidella) pannula maladensis.
malvernensis [Acrotreta (?) sabrinze], Matley [1902, pp. 143-144].......... Acrotreta sabrine.
manitouensis [Schizambon], Walcott [mew]. ..-....---.----------------- Schizambon manitouensis.
manticula [Lingula?], Walcott [1884b, pp. 18-14]....-...-.......---..-.- Lingulella punctata.
\Wianinits [UES45 Teles OO | Soc codaascancesacazcoosesode Lingulella arguta (in part) and L. manti-
cula (in part).
White [1877, pp. 52-53, Pl. III, fig. 2a]............- Lingulella arguta. The text also includes
L. manticula.
\Waulines |USV/e, 10> 2, Tell, WOE, te, Doe ccsaccscossoccos Lingulella manticula. The text includes
L. arguta.
marion [Billingsella], Walcott [1908d, p. 102].-...-..-....-.............- Billingsella marion.
marjumensis [Acrotreta], Walcott [1908d, pp. 94-95]. --.............---... Acrotreta marjumensis.
martinensis [Lingulella], Matthew [1890, pp. 155-156]................... Lingulella martinensis.
Matthew [1895a, pp. 118-114]......-..-........ Do.
matinalis [Lingulella?], Walcott [1897a, p. 404]......-........-..-.....-- Obolus matinalis.
matinalis [Lingulepis], Hall [1863, p. 180]....-.......-..-.......--..... Do.
ETAL [S67 pAdOT]e oe eo ee Name Do.
matinalis? [Obolus], Walcott [1905a, p. 325]. .-.......-.--.-.--..-...---- Obolus matinalis?.
matinalis [Obolus (Lingulella)], Walcott [1899, p. 443].........-.. ee eoS Obolus matinalis.
matthewi [Acrothele], Grabau and Shimer [1907, p. 200, fig. 234f]........ Acrothele matthewi.
Grabau and Shimer [1907, p. 200, fig. 234e]......... Acrothele prima.
Hall and Clarke [1892a, Pl. III, fig. 24]...........- Acrothele matthewi.
Hall and Clarke [1892c, pp. 99 and 100]............ Do.
Matthew, (11886) pps sO =4]ee = = 2 aes ee ee Do.
Maitreya [iS 9 5arn peel 28) sas eae eee es Do.
Matthew [1902b, pp. 397 and 402].................- Do.
Wanna |NOO8, 0. MOA cososcesooessosescscaesecce Do.
Walcott|[1S84arnp bl. ee ccceesccsen ee eee Do.
Wahoos (IESG 9}, 1O5 UO). - cessccscessesesasccseacn- Do.
Werlooine [SMe Ts USS Saesccecscsdasocssausseeoe Do.
matthewi [Lingula], Hartt (1868, p. 644].....--.22.--.....--4...--.+5.- Do.
far tin[SiiSiypnG44)) = craves serie ee cee eee eer eee Do.
: Efantt (SOU kp 644] 1. 22025. cee ee ee ee Do.
matthewi costata [Acrothele], Matthew [1895a, p. 128].................... Acrothele prima costata.
Matthew, [iiG02b; 7p: 397] sseeeea- ae eee Do.
Matthew [190355 104 ]S ae aeee ee eeee sees Do.
matthewi eryx [Acrothele], Walcott [1905b, p. 11].......-..............Acrothele matthewi eryx.

62667°—vot 51, pr 1—12 5

66 CAMBRIAN BRACHIOPODA.

Present reference.

matthewi lata [Acrothele], Hall and Clarke [1892a, Pl. ITI, figs. 25 and 26]. Acrothele matthewi lata.

Hall and Clarke [1892c, Pl. III, figs. 26-28]... - Do.
Matthews [S865 paleo ecee. - =o seeeee ee Do.
Matthew [1895a, Pl. V, figs. 8a-b]...--..-..-- Do.
Matthew [1903; p. 104)_.-.. 282.22. 5222-2. Do.
matthewi multicostata [Acrothele], Matthew [1897b, p. 168]. .....--.-.--- Acrothele matthewi multicostata.
matthewi prima [Acrothele], Hall and Clarke [1892a, Pl. III, fig. 27].....Acrothele prima.
Hall and Clarke [1892c, Pl. III, fig. 25] ...-- Do.
Matthew [1886, p. 41]...-.....-.--..------ Do.
Matthew [1895a, Pl. V, figs. 7a-b] ......-.-- Do.
Matthew [1902b, pp. 397 and 402].........- Do.
Matthew [1903, p. 104]. .......---..------- Do.
maximus [Obolus apollinis], Mickwitz [1896, pp. 140-143]..........-..-.-- Obolus apollinis maximus.
meeki [Lingulepis], Walcott [1897a, p. 405]. ......-..-....--.-------.--- Lingulella (Lingulepis) acuminata meeki.
meeki [Lingulepis acuminata], Delgado [1904, pp. 366-367]......-...----- Lingulella delgadoi.
meeki [Obolus (Lingulepis) acuminatus], Walcott [1899, p. 444]. . . ......-Lingulella (Lingulepis) acuminata meeki.
Meekina prima Walcott [1905a, p. 313].--..-..--.-------.----++--+------ Linnarssonella tennesseensis.
melita [Dalmanella], Schuchert [1897, p. 202]..........-....-...-------- Variety of Eoorthis desmopleura.
melita [Lepteena], Hall and Whitfield [1877, p. 208] ..-.......---.-------- Do.
membranaceous [Obolus], Walcott [1908d, p. 61]..---.....---...--------- Obolus membranaceus.
meneghini [Obolus (?)], Walcott [1901, p. 684]......-...-..--..---.---.-- Obolus? meneghinii.
Metoptoma sabrinze Callaway [1874, p. 196] ....--.---...--- Deeewoscuase Acrotreta sabrinee.
(Mickwitzella) [Obolus], Walcott [1908d, p. 70]. -..-...--..-------------- Obolus (Mickwitzella).
Walcott [1908e, Pl. XI, and pp. 142 and 144].-.-. Do. :
mickwitzi [Obolus], Walcott [1898b, pp. 386-387]. ....-...--..---.----2-- Obolus mickwitzi.
Mickwitzia Hall and Clarke [1892a, p. 246].......---..----------------- Mickwitzia.
Evalliltands@lankel|il892 besos 62) emia eee eee eee eeere Do.
Hall and Clarke [1892c, pp. 86=87]. ....-..------..---------- Do.
Schmidt, [W888i pees eee eee. Mae ano esos Ancor Do.
Walcott [1908e, Pl. XI, and pp. 142 and 143]...-...........- Do.
Mickwitzia? major Mickwitz [1896, p. 23]. - Bere ..-----Rustella? major.
Mickwitzia monilifera Hall and Clarke [1892a, fas 953-255, io. 246], ceCanaes Mickwitzia monilifera.
Hall and Clarke [1892b, figs. 253-255, p. 562].......- Do.
Halllvand Clarke) [1892c)p. 86]b2---2 2252-22-22 = - Do.
Schmidt [1888, pp. 21-23 and fe pA eee AN UP aa Do. 4
Walcott [1891a, Pl. LXX, figs. 2, 2a-h]..........-- Do.
\iviienenal [ISO 0s HEI Sooacuuecooeoudonebsoseoouooeos Do.
Mickwitzia occidens Walcott [1908d, p. 54]-:.-....-..-.--.--.--.-------- Mickwitzia occidens.
Mickwitzia pretiosa Walcott [1908d, pp. 54-55]. ...-.-..--.--.----------- Mickwitzia pretiosa.
Micromitra Meek) [SZ air A79l|aeeee ee toss ce aes soe Se) akon eae Micromitra.
Walcott [1908e, Pl. XI, and pp. 142 and 143]............--.-- Do.
(Micromitra) [Paterina], Schuchert [1905, p. 329]...........-.--.--.----.- Do.
Micromitra haydeni Walcott [1908d, pp. 55-56]. .-.-.-.-.--.------------- Micromitra haydeni.
Micromutnarscotica Walcott) |mewi|ae-eeeeeneeeeee cree sree eaeeeree eee eres Micromitra scotica.
Micromitra sculptilis endlichi Walcott [1908d, p. 56].......-..-.-..------ Micromitra sculptilis endlichi.
Wihkenoranlling, Zemoone, Wealkeoue |iey||s cacocssoossodescougcdcconnencccesuuae Micromitra zenobia.
Micromitra (Iphidella) Walcott [1908e, Pl. XI, and pp. 142 and 143].....-. Micromitra (Iphidella).
Micromitra (Iphidella) louise Walcott [1908d, pp. 56-57]...-.--...--..---- Micromitra (Iphidella) louise.
Micromitra (Iphidella) nyssa Walcott [1908d, p. 57]...-..------.-...----- Micromitra (Iphidella) nyssa.
Micromitra (Iphidella) pannula Walcott [1908c, p. 244, Pl. I, figs. 1, la-c]. Micromitra (Iphidella) pannula.
Micromitra (Paterina) Walcott [1908e, Pl. XI, and pp. 142 and 148]-.....--- Micromitra (Paterina).
Micromitra (Paterina) labradorica var. undt. Walcott. [new]---..-.-------- Micromitra (Paterina) labradorica var. undt.
Micromitra (Paterina) stissingensis ora Walcott [new].-------..--.----=---- Micromitra (Paterina) stissingensis ora.
Micromitra (Paterina) stuarti Walcott [1908d, p. 58]..-........-..--.------ Micromitra (Paterina) stuarti.
Micromitra (Paterina) wapta Walcott [1908d, p. 59]-.---..-.---..-.------- Micromitra (Paterina) wapta.
Micromitra (Paterina) williardi Walcott [1908d, p. 60].........-..--.--.-- Micromitra (Paterina) williardi.
microscopica [Discina], Shumard [1861, p. 221]......-...-.-..-.--------- Acrotreta microscopica.
microscopica missouriensis [Acrotreta], Walcott [1902, p. 590].......-....--Acrotreta microscopica missouriensis.
microscopica tetonensis [Acrotreta], Walcott [1902, p. 590]....-...-..---.- Acrotreta microscopica tetonensis.
minima [Lingulepis], Dwight [1886, p. 208]......-..-..-.--....-.--.--.-- Lingulella (Lingulepis) acuminata.
Whitfield [1884; sp. 140)... 2225225. -2-2252dscecnene: Do.
minimus [Obolus?], Barrande [1879b, Pl. XCV, figs. m: 1-5].-.....-...... Acrotreta? minima.

minimus [Obolus], Walcott [1905a, pp. 325-326]. ....................-.-- Obolus minimus.

SYNONYMIC REFERENCES. 67

Present reference.

minimus [Obolus (Lingulella) lamborni], Walcott [1898b, p. 407]. -.-------- Obolus lamborni minimus.

minor [Acrothyra], Walcott [1905a, p. 303] -...-....-.------------------- Acrothyra minor.

minor [Camarella], Hall and Clarke [1893b, p. 221]..--..--.-..------------ Obolella minor.

minor [Camarella), Walcott [189la, p: 614]-22- 2... 2222222222. seek --- == Do.

minor [Camerella], Walcott [1890b, pp. 36-37]......-.--..---------------- Do.

minor [Lingulella starri], Matthew [1892, pp. 58-59]....--.--..------------ Lingulella minor.

minor [Obolella], Clark and Mathews [1906, p. 252]-..........------------ Obolella minor.

minor [Obolus?], Barrande [1868a, p. 105]. ...........-....-------------- Obolus? minor.
IpyniennGl® [KTH Ws CPB eo cos oe SticeooeseccSouceenscesce Do.

minor [Protorhyncha?], Schuchert [1897, p. 334].....---.-..-.------------ Obolella minor.

minuta [Acrothele?], Walcott [1905a, p. 303]......-...--.---------------- Acrothele? minuta.

Tania, [LAeromeal}, Welleount (MO, 105 OiBllescacoscce esaceoccatesas=scsece= Linnarssonella minuta.

muintiiay |emeulellapschuchert [1897 1p. 257) e-eesseeeeesess see essen ae Do.

minuta [Lingulepis?], Hall and Whitfield [1877, pp. 206-207]. ........---- Do.

Wialeotts [884 sip. 13] Seeeeae eee ee eee ee ee Linnarssonella minuta (in part).
minuta [Linnarssonella], Walcott [1902, pp. 603-604]..........-...---.---- Linnarssonella minuta.
minuta [Obolella?], Walcott [1897a, p. 404]...........---.--.------------ Do.
minwta)|(Obolella|* Walcott [18995 p. 443]- = 5222222282 see ees eee Do.
minutissima [Kutorgina], Hall and Whitfield [1877, pp. 207-208]........-- Micromitra sculptilis.
minutus [Obolus (Schmidtia) obtusus], Mickwitz [1896, pp. 175-177]. ---.- Obolus (Schmidtia) obtusus.
Tiga Worst], \Weilleorns, [lew esccosesetecasaceasoesssqsnecscucseesncac Yorkia miqueli.
miranda [Lingula?], Barrande [1879b, Pl. CXI]--.....--......---.---.--- Obolus? mirandus.
miser [Acrotreta], Walcott [1902, pp. 590-591]........-....-.------------- Acrotreta misera.
miser [Obolella?], Billings [1872b, pp. 470-471]. ....--..--.--.----.------ Do.

j Billie s S74 paiGO Ss. 2 a1 cee he eee ee ey ree rape Do.
misera [Linnarssonia], Hall and Clarke [1892c, pp. 108 and 109] --.....--.- Do.

Matthews [ilSS65 ppsico—o6] eesssee es asee eee see eeee ae Do.
missouriensis [Acrotreta microscopica], Walcott [1902, p. 590]---...----.--- Acrotreta microscopica missouriensis.
mobergi [Obolella], Walcott [1901, pp. 673-674].........-...-.-.--.------ Obolella mobergi.
WiGoeredey IReclliela [EOE joi). O0l|s saaaeaoescseceosesseca=eocesaceoosseoc Botsfordia.

Mobergia granulata Redlich [1899, pp. 5-6]......-.....-.----------------- Botsfordia granulata.
modesta [Linnarssonella], Walcott [1908d, pp. 90-91]. .-......--..-..---.- Linnarssonella modesta.
Monobolina refulgens Matthew [1903, pp. 210-213].....................-- Obolus refulgens.
(Monobolina) refulgens [Obolus], Matthew [1902c, p. 98]..-...---.-------- Do.
monilifer [Obolus?], Linnarsson [1871, pp. 9-10]. ....--..---.------------ Mickwitzia monilifera.
monilifera [Lingula?], Linnarsson [1869a, p. 344]..-.....-.-..------------- Do.
monilifera [Lingula], Linnarsson [1869b, p. 398].........--.-.------------- Do.
monilifera [Mickwitzia], Hall and Clarke [1892a, figs. 253-255, p. 246]...... Do.
Hall and Clarke [1892b, figs. 253-255, p. 562]. --.- Do.
Tell eva! Cllandkee [MERHO) 19. tG)|- 5 25s scoasecoseue Do.
Schmidt [1888, pp. 21-23 and 24-25]............- Do.
Walcott [1891a, Pl. LXX, figs. 2, 2a-h]...-....... Do.
Whiner [[IGO2; Tos Bll secocccconccososacauaceocsse Do.
montanensis [Polytcechia?], Walcott [1905a, pp. 295-296]..........--..--.- Clarkella? montanensis.
mame), |[ibianeuiley | Jelevll |ikstae}, (O, TEX) |Ledecapssoedecseeses sosecconsccessuces Lingulella mosia.
Jeleyhl (MSG, jor, C208) se saccsescccosadscssscsocspecnens Do.
Seiler, (EG 1s COs aaeoacesacessoscesbaccancasosdor Do.
mosia osceola [Obolus (Lingulella)], Walcott [1898b, p. 409]...--..-----.--- Lingulella mosia osceola.
multicostata [Acrothele matthewi], Matthew [1897b, p. 168]..........-.-.- Acrothele matthewi multicostata.
murrayi [Obolus?], Billings [1865b, p. 362]....-........--.--------:---.-- Obolus? murray1.
N.
namouna [Obolus], Walcott [1898b, p. 390]............--.--.--.----.--..- Obolus namouna.
nana [Obolella], Billings [1862d, pp. 67-68]..-....-...-.----.----.------- Dicellomus nanus.
ieallfands Clarke) [892c) pp. 69=/0]bss-esesseeeeese- 4 ee Do.
Hayvdeng S62" s73 as- 65: 5 iss se a5 een eee reer Do.
Meek and Hayden [1862, pp. 485-436].........-.....-.-- Do.
Meek and Hayden [1865, p. 4]..-....-.-.---.--.-------.- Do.
VWVelieon |MeG oO, Tos WW |S >= ceeecetoceasesacaoneccsosoosecs Do.
Whitfield (1880, pp. 340-341]. ....2.-2.2..2.2-5-2------- Do.

nanno [Oboltts (Lingulella)], Walcott [1898b, p. 409]..................---- Lingulella nanno.

68 CAMBRIAN BRACHIOPODA.

Present reference.

manus [Dicellomus]; Walcott [11899, p. 447]5.--- 22 Lingulella desiderata (in part) and Dicel!o-
mus nanus (in part).
Weileoiii [SOSH joo), HIG BING]. wooo bbe enc seoecaos- Dicellomus nanus.
nathorsti [Lingulella?], Linnarsson [1876, pp. 15-16]....................-. Lingulella nathorsti.
nautes [Protorthis], Walcott [1905a, pp. 283-284]......................... Nisusia (Jamesella) nautes.
neboensis [Acrotreta], Walcott [1905a, pp. 300-801]........................ Acrotreta neboensis.
nebulosa [Genre? sp.], Barrande [1868a, pp. 105-106].....................- Orbiculoidea contraria.
Barrande [1868b, pp. 693-694].......... ere nae Do.
INeobolustealllfands Clarkes [is92 ana 22] eee ae nn nC Neobolus.
Islet emavel Qhvaee |[MEB20, 7). SOM ooseccosseeos-cesesascacaseesaese Do.
JaleMlll cnavel Cllevdke |[USQRO, joe BH ceoescscede se 2252-osseseconeoseas Do.
Oshlertip1S87Ap 1263 eases a eee ea cee ame Do.
Wenger (G5, io THOME). -coescecceccsecelecsgezelecczeceace Do.
Weleatit MODS, jo. WAM seksdawed sade elses sec occceenee ec. Do.
Walcott [1908e, Pl. XI, and pp. 142 and 144] .............._.... Do.
Neobolus warthi Frech [1897, Pl. IA, figs. 5a-b]-........................ Neobolus warthi.
Jel cual Clerake USCRE, jos 2HO]|. oosccocscéeseesce=ssscns Do.
Telenbl eyavel (Cileilixe) [S29 10), BGIl||s25<c6-c5e25-ceeneecom sae Do.
HlallGanan@lamke [iS 92 cei pS Ai pee eee ae Do.
Oyeailerts (MENS /5 ids WAGES saat seeacadsokusabacondaspsosooe Do.
\Weererein (IGE), 7919, TSS |e os oce4-0055=sc0b0nseese452cu- Do.
Weer |S, Teal, IU, ies, H8)] cosc245455essscansesnnuec Do.
Neobolus wynnei Waagen [1885, pp. 759-761].-.......................-.. Do.
Werrereia [SIL IAN, IW ines, 10) epavel WN)o ec ccesasns s2escese Do.
newberryi [Hoorthis], Walcott [1908d, p. 105]..-......-...-.-....-.....-- EKoorthis newberryi.
newtonensis [Orthis], Weller [1903, pp. 118-114]... .-.................-..- Eoorthis newtonensis.
newtonensis [Orthis (Plectorthis)], Walcott [1905a, p. 267]....-.......-..-- Do.
nicholsoni [Acrotreta?], Davidson [1868, pp. 318-314]....................- Acrotreta nicholsoni.
Davidson [1871, pp. 848-344]...................-. Do.
nicholsoni [Acrotreta], Davidson [1883, p. 213].-.-.....................-. Do.
Ealivamadt Clarice} [HS92c spel 03) pases = sees eee Do.
Swanston [1877, Pl. VII, figs. 2la-c] ..............- Do.
Swanston [1886, Pl. VII, figs. 2la-c] ..............- Do.
nicholsoni [Acrotreta sp. cf.], Matley [1902, p. 142]....................... Acrotreta sabrine.
nicholsoni [Lingulella], Callaway [1874, p. 196]-..-..--............-....- Lineulella nicholsoni.
Callaway (1877, pp. 668-669].-...-.......-....-.- Do.
Davidson [1883, pp. 208-209].-.............------- Do.
nicholsoni? [Lingulella], Matley (1902; p. 141). -:--.--..-......._._._.... Do.
ninus [Obolus tetonensis], Walcott [1905a, p. 328]..............--.....-.. Obolus tetonensis ninus.
nisus [Iphidella], Walcott [1905a, p. 305]--...---.......-.--.-----.--.----- Micromitra nisus.
Nisusia Grabau and Shimer (1907, p. 210]..--.....-..-..-..-.--..-------- Nisusia.
Welleiott [MEWS (oI PATOWAR seco ek Sse eke ean sasdo-useseane- Do.
Walcott [1908e, Pl. XI, and pp. 142 and 147] ..................... Do.
Nisusia alberta Walcott [1905a, pp. 248-249]..-...........-...-.....-.--.- Nisusia alberta.
Walcott 908e mo ( 245) Bae eer ecm Mie yan tetaen op te Do.
Nisusia festinata Grabau and Shimer [1907, p. 211]......................- Nisusia festinata.
Walcott [1905 pp: 249=2bill| pases sees eee ene ee ene. Do.
Nisusia festinata transversa Walcott [1905a, p. 251].........--...--..---.- Nisusia festinata transversa.
Ng uEteD Tae, Walkooit [MOstcl., > Oi ssceoneabascacasssacsocccsscescsnce sess Nisusia rara.
Nisusia (Jamesella) Walcott [1905a, p. 252]. 22 2-2225.---2.222222-2 22 - -. Nisusia (Jamesella).
Walcott [1908e, Pl. XI, and pp. 142 and alee Bete Ae Do.
Nisusia (Jamesella) amii Walcott [1905a, p. 252]... a ...-.---------Nisusia (Jamesella) amii.
Nisusia (Jamesella) argenta Walcott [1905a, p. 252]. ee ee ce sya epee tate era Nisusia (Jamesella) argenta.
Nisusia (Jamesella) erecta Walcott [1905a, p. 253]...-...--..---.---.---.- Nisusia (Jamesella) erecta.
Nisusia? (Jamesella?) kanabensis Walcott [1908d, pp. 97-98]..-...-...--.- Nisusia? (Jamesella?) kanabensi<.
Nisusia (Jamesella) kuthani Walcott [1905a, pp. 253-254].............-.-- Nisusia (Jamesella) kuthani.
Nisusia (Jamesella) lowi Walcott [1908d, p. 98]... : ....-.----Nisusia (Jamesella) lowi.
Nisusia (Jamesella) perpasta Walcott [1905a, pp: 254-255]. LU 2 Atay pr a Nisusia (Jamesella) perpasta.
Nisusia (Jamesella) perpasta macra Walcott [1905a, p. 255]............---- Nisusia (Jamesella) perpasta macra.
Nisusia (Jamesella) perpasta subquadrata Walcott [1905a, p. 255]. . .......Nisusia (Jamesella) perpasta subquadrata.
Nisusia (Jamesella) utahensis Walcott [1905a, pp. 255-256]...............-- Nisusia (Jamesella) utahensis.
Nisusia (Jamesella) sp. undt. Walcott [1905a, p. 256]..-.-.--..--..--.----- Nisusia (Jamesella) sp. undt.
nitens [Linnarssonella], Walcott [1908d, p. 91]...---.....---..------------ Linnarssonella nitens.

nitida [Linnarssonia’?], Walcott [1901, p. 673].-.---..-..-.-.--.--.--.-----/ A crothele nitida.

SYNONYMIC REFERENCES.

69

Present reference.

aiiidag| @bolellai|tskordy|il8735 ps 213) sense esas a= re eee eee Acrothele nitida.
Grabau and Shimer [1907, p. 189]-..---.--/------------- Do.
JEN emavel (Cle vale MEBAC, jf), WOecesacacssscecsccussssoaese Do.
Wallleoiti (MSG, jap. WIT). essa se ccc wes eecescoe Do.
Walco vt S9Nay 19-62 i] eee a sions cee eye ot rect sores Do.
notchensis [Obolus (Westonia)], Walcott [1908d, p. 69].....---------------- Obolus (Westonia) notchensis.
nox [Acrotreta], Walcott [1905a, p. 301]................--------+--------- Acrotreta nox.
nundina [Obolus], Walcott [1905a, p. 326]. ..--..--..--.----------------- Obolus nundina.
nundina [Syntrophia], Walcott [1905a, p. 292]...............------------- Syutrophia nundina.
nunnebergensis [Protorthis?], Walcott [1905a, p. 284].--..--..------------- Protorthis? hunnebergensis.
nympha [Orthis (Plectorthis) desmopleura], Walcott [1905a, p. 262].......-Eoorthis desmopleura nympha.
nyssa [Micromitra (Iphidella)], Walcott [1908d, p. 57]--.------------------ Micromitra (Iphidella) nyssa.
One
Ojaollellie, 1Biilllinrovers} [TYG S), Te Wlacoccsosasseesossesccosaccoseoudeoaeses0c0s Obolella.
Billings: PSE paGAG ees ccse Neste fe eee eee ee Meee eee Do.
IBylUhicarers [MIVAS, joy, CAO BAl| Ls oosdeas secnsosocsseesoodsodceaoesc Do.
Billimos|[WB62e yore Sl ease ec sam es se oe avec eee aisle tests Do.
TByilhivaree) (MIAH, jojo ALGAAS oo saseone = sosconedooocaoocncdescess Do.
IBllltings |[MGIPAO, iO. SOP lledasecaasoaacenaceceacoqssooussousce Do.
1Brilliniavess\ [MSG Joos WAG Asl Loeasccosees soscssscecocsouoobboesecs Do.
IDR USA, Toros Wa! einol GS) sooteaccso< + acsecsoconaddouseconede Do.
Denpi@lsom [MIGG; 19> GO] bosaasecovoscostecaseacesoossocoososnases Do.
Deanmolsoyn |[WGS, To, HUSA bocce ease seacenesccunadsseqsancacss Do.
DeniGlsorn |[MEVAl, oyns G8E=seOl acasceosncoasecocssacuduscosucccec Do.
Ford [SSI pp. Voll ee here sce ce icy -jaci- cern sectes eects etna Do.
Grabantan di Shimer (1907, oul SS) Seessse- = eee ee eee eee eee Do.
TAMAS 63s e POM Roepe te sat cts vce teciw eoinan ete aaa ie see Do.
FGM (MS Grenp OS) oacissecslactee cee ae nas aane sac ptseanys cise eee Do.
Hall and ‘Clarke [1892a, pp. 240-241]............-.....2-------+--- Obolella (in part) and Dicellomus (in part).
Hall and Clarke [1892b, pp. 556-557]. ...-.-.....--.--.--------- Do.
Hall and Clarke [1892c, pp. 66-73 and 164-165] ...--.-.....------ Obolella (in part), Dicellomus (in part),
Bicia (in part), Obolus (in part), etc.
Meatihewall892) ppy39-40)] Ae ace tepeee = somos <oo none eines eee ae Obolella.
MeeksandtElay dent [86a pps o—4leeeseesee see eases ees eae ee Do.
Mickwitz (1896, pp. 116, 121, and 123-126]-..-.../.......--.----- Do.
Oehilenty S87 wor I 262] yee yess = oss = cates oe eroae em eee eee se Do.
Obolellar Walcott [884 \ipp! 67-68] see eee o-oo eee eee Do.
Obolella Walcott [1886b, pp. 109-112]........-...-......----+-+----------- Do.
Walcott [1908e, Pl. XI, and pp. 142 and 145] -...-.......-..-..-- Do.
Sissi oN LUHSIOS Fav 102 eV eee mee OR Do.
Obolella? ambigua Walcott [1884b, pp. 67-68]........-....--------------- Elkania ambigua-
@bolellayasiatica Walcott ['905a; pp, 297|/2-2.-22---4-----255222-- 2225-252 2ee Obolella asiatica.
Ooh, gilbmingn, Bier MO), joo |ssconscoossesaasa soscoaanasdasanccsese Obolella atlantica.
(Crordmennn (UG), LL, WH, Wes, PRR) oscsccosscecesescaaesao= Do.
Eimloawi [MOO joy), GADAGAN | <5 oe eae cuasasssecessesc Do.
Grabau and Shimer [1907, p. 188].......-..--..--..--.- Do.
MEO (MEE To70) Pecesssessssseee saeseanasenscstcs Do.
\Wrelleotie MEO; 106 iol lpassacuduccenaacdseaododdesacssoc Do.
\Waikeor (MeOila, 7s GI see.sssscssceesaaessaesco= acer Do.
Obolella cf. atlantica Delgado [1904, p. 364].............--......-.-..---.-Obolella? sp. undt.
Obolella belti Davidson [1868, pp. 310-311]................-.--.----.---- Acrotreta belti.
IDeaywaels(orm |[ISi/AL, joa), SRO SVAN ee one oe seccce ae socsssssecsas De.
Obolella ceelata Billings [1872a, p. 218]..-..-.....--..-.--....-...--..-----Botsfordia celata.
Obolella chromatica Billings [1861b, pp. 7-8]...--.--..------------------ Obolella chromatica.
TBA bares) (UTS, jo, CAV oonesosecuasenessgsssesceeooue Do.
BFlimeas [Gee iy PU eaate dene eee Ree eu ee Do.
iBillines [S635 5284) sees eee eee eee eee Do.
Be Maves (HG, WD. UPA sac scesacnccoseeeeeeceoee DD:
1DCigel | PICKLE oy el PS AEeeR eee ecobeasses acHosrapedtome Do.
fal [S63 po al 32 ee os Se ae or seesemes oe oe ese se Do.
alls WS 6 7A ll Ol eee baie tose nasal ae See maine ee Do.
Haliandi@lakes [89267 0.67] s--ee eee eee ates Do.
Om Woilll [MOS o 2il|-casssacceoscscases oes ren paee (?) (See p. 592.)

70 CAMBRIAN BRACHIOPODA.

Present reference.

Obolella chromatica Walcott [1885a, pp. 115 and 117].--.....--.-...-.....- Obolella crassa.
\veKoorny | MEG}, (Os JOY | oadesccnopaccasesnassesoesdese Obolella chromatica.
Walkers (Me, TO, GIl|.ssccessscssssecesorasesccesene Do.
Waillcottsfili9 944 Gl Meee eases eet ere eee ee Do
Walcott [1905a, p. 313]-- Bet a cle ain vec aera eemeens ap Do.
Obolella cingulata Billings [1863, p. 284, figs. 287a-b] .. dit Ss eae ea US Kutorgina cingulata.
Billmes [863 py284shies287e)] esse) see eee ese nee Rustella edsoni.
Obolella ciree Billings [1872a, pp. 219-220]........-..--.-.--+---.------- Quebecia circe.
Iwill biavesss [MeVe2AO, ToD, GHI-BaSl b asaeoecuescscsoocoscuesneaacs Do. e
Walcott) [IS86b5 ips 18) Pi exe vfie. B]p = 24-2255 se eee ae Obolella chromatica. The text includes
Quebecia circe.
Wearleoris [ISSGO, 1D, UIs, IAL 36, ie, Billo. 22 s2sosccccoesccsce Quebecia circe.
Walcott [189la, p. 611, Pl. LX XT, fig. 3]..................- Obolella chromatica. The text includes
Quebecia circe.
Walcott [1891a, p. 611, Pl. LX XI, fig. 3a]-.....-........... Quebecia circe.
Obolella circe? Walcott [1891a, fie. 62, p. 611].-.--......--...--..........- Obolella crassa.
Obolella?? complexus Hall and Clarke [1892c, p. 73]....-..-..-.--------- Obolus complexus.
Obolella crassa Billings [/872a, p. 218]---.---.---...._.-...4----- == 2-2. Obolella crassa.
{Subbu | MAS, Tey SHO |escdoasebecooncssesaeadasuosos scone Do.
Bornemann [1891, pp. 489-440]..............-.-.--------- Obolus? zoppi.
THO coli| les To wdWtell paasaaadaeaacoonose cesses caseseccesene Obolella crassa.
Ford [1881, PP. TES) PAE oer cs Mean Seo Sanat aacmmcee cc Do.
Ford [1886a, fig. 2, p. 466]... Faery ie Dees ns enna ae Do.
Gorham [1905, ‘PL. I, figs. Tes. eee ee ee eee eee eee Oboleliajatlanticar
Grabau and Shimer [1907a, pp. 188- -189].. Pea ene a Oae Obolella crassa.
Hall and Clarke [1892a, Pl. III, figs. 5-7]............--.--- Do.
Isle enavel Clowes MERWE, jo), (Ol\eoo2sccscacnesecoccocssecess Do.
Shaler and Foerste [1888, p. 27]....--..-.-...------------- Obolella atlantica.
Avene las (RHO, IOs Al sentacsesocs sea sdabocseanaceeoadscc Obolella crassa.
Walcotty [I 8S6b ios iia peaience means cme oes Do.
Walloon stiles joy Gila|booaaosesaaNaasaesssonseocussaascee Do.
Walcott [l9 Oban momo zit pera ere ere: ese eee Do.
Obolella crassa? Grabau [1900, pp. 619-620]...........-....-------------- Do.
Obolella crassa elongata Walcott [mew]..-......--------.--.---.---------- Obolella crassa elongata.
Obolella desiderata Billings [1862d, pp. 69-70].....-..--..---.----------- Elkania desiderata.
Denvacclsoun [MEG 1, AUD) |sos-secesceedsccessssesocsacces Do.
Obolella? desiderata Walcott [1886b, p. 111]....--....-----..-------.---- Do.
Obolella desquamata Billings [1872a, p. 218]...........-...--..----------- Obolella crassa.
. Billings [1'872¢, p./356]---2----------------- tao) Seeee Do.
Obolella discoida Hall and Whitfield [1877, p. 205]...............-.....-- Obolus discoideus.
Obolella? discoidea Hall and Clarke [1892c, p. 69].....---..---.-..-------- Do.
Obolella discoidea Walcott [1884b, p. 14]........-.-...--.--------------:- Do.
Obolella? discoidea Walcott [1886b, p. 111].............-....-....--..---- Do.
Obolella gamagei Hobbs [1899, pp. 114-115]........-......................Acrothele gamagei.
Obolella gemma Billings [1872a, pp. 218-219]._.................-...--.--- Bicia gemma.
Bailing s| [8720s e300) | see eee eee ee eee ree Do.
Hall and Clarke [1892c, pp. 69 and 71]..........-..- CUS Do.
Walcotty TSS 6b ys pp aelG S17] Seeeee= see eee eee Do.
Walcott) [1SOlakips G2) Ree eb se eee eee eee eae Do.
Obolella? gemmula Matthew [1892, pp. 41-42]...-..........---..--.------ Lingulella ferruginea.
Obolella (?) groomi Matley [1902, pp. 137 and 139]........-...........-.. Obolella groomi.
CO) ovopleillke, suoley Veuilbuavessy | [MAC To), WY |accas ca socesse saeccesenacsscoenccesss Elkania ida.
Obolellandaz’Dawsonel888a,npwodleeseeesee ee ener eeee eres eeeeeeeeeeee Acrotreta sagittalis.
IDE Asal | PUSKII 0} 10s 11 Leacouue sus dooeaeoeboeeeseoseeoo sSses Do.
Ojoolellyy? ile, \Wenlkeoitis [MENG , jo, WY ocsesoecaoesecsesascaseesecsssaces Elkania ida.
Obolella lindstrémi Walcott [1901, pp. 674-675]...........-...--..-------- Obolella? lindstrémi.
Obolella maculata Davidson [1868, p. 311]-...-.-...--...------------------ Acrothele maculata.
Dawadsony [Sicily er 3Aill| Beene aan eee Do.
Deleadoi[l904 ps6). eseseces- aso oa- cic oan nee Acrothele villaboimensis.
Spiller (MAK. (5 Adal eegonssseaasessccsaseebsasesccese Acrothele maculata.
Obolella minor Clark and Mathews [1906, p. 252]................-.-...--- Obolella minor.
Obolella minuta Walcott [1899, p. 443]..................-...-..--..--..- Linnarssonella minuta.

Obolella? minuta Walcott [1897a, p. 404]............--..-..---.---..---- Do.

!

SYNONYMIC REFERENCES.

Present reference.

Obolella? miser Billings [1872b, pp. 470-471]..............-..----------- Acrotreta misera.
Billings) [S74 si. -69i] se eeeeee sas Na eee ere ene Do.
Obolella mobergi Walcott [1901, pp. 673-674] .................-..---.--- Obolella mobergi.
Obolella nana Billings [1862d, pp. 67-68]....................--.-...---.- Dicellomus nanus.
Hall and Clarke [1892c, pp. 69=70].....--.:..-.-..--------- Do.
Hay dent |lS62 5 pw73liassnaeeeaaa- Sore ne eee eee Do.
Meek and Hayden [1862, pp. 435-486]..........-...------- Do.
Wikealle cual leleny len (May, tos Clos ocss 5505-50 scessoccoce=- Do.
Wakeouit [MSSG)9, jo. IY |p coe sec oasneansencesscsecscedencee Do.
Whitfield [1'880, pp. 340-341]. ......../............-.-.--. Do.
Ojoolelly sartingks, (ose! MSGS (Os AUB ssocsccoess= 5 aocaccauocecssbescenecesnc Acrothele nitida.
Grabau and Shimer (1907, p. 189]-..-.-.--.-..--.--------- Do.
Tskalll eine! Clenak@ | Re. jo). (Olle oo 5 a= acceccacecccasecsocec Do.
Werlkoonitt |USEIG0), jays TUNIS osc cossocosseeonesesceosescu Do.
Wallet [WEE jo, GIA coconssccadacoseeGesccacdacesdocue Do.
Obolella parvula Wallerius [1895, pp. 65-66]...........---.-------------- Acrotreta parvula.
Obolella pectenoides Schuchert [1897, p. 275].........-.----.------------ Dicellomus pectenoides.
Obolella? phillipsi Davidson [1866, pp. 62-63]..........-..-..---.-------- Micromitra (Paterina) phillipsi.
Obolellagohillijpsi OMI S65) po. VO2|ss= see ae eee nee eee Do.

JPAmuillibtjoys) EVAL, to GS hc aoassocococedoccooecascseeuaeous Do.
Oholellagphulilipsias Walls [WS 4s eee ee sae aoe ee Do.
ObolellaypolutayBulllimes) [MS62c5 jo. 42il|pas se 22 ee ae eee ese a aee Dicellomus politus.
Obolellarzpolitapelall! (N863> pp. W83=184] 222-2222 22- 4252-2 - sss ee ae eee Do.

ELAM ISGTA pie L121 yee tae eee eee eee en a Do.
Obolella polita Hall and Clarke [1892c, pp. 72 and 73]......--.----.-.----- Do.
Wrallcott[HS8 Glow Millie oe ee Se yl. 2 eee ere eae eee Do.
\yVlamiiverelkel | [MSHO), yoy os BRUSH Ccococcsescacccescdaucesbusce Do.
Obolella pretiosa Billings [1862d, pp. 68-69].........-..--..---.--------- Acrothele pretiosa.
IBrllltiraeys [EGS Os ZO ocasconcsuncecseapsacessceaceces Do.
' Clngyonmein (MGR, Tos WOM coceoncecus sabec os accecesbeooeece Do.
Clnajormenn [UAV jo, UGB) osescasescesbassscqescoescescass Do.
Obolella? pretiosa Walcott [1886b, p. 111]-......--..-:-.--..--.--------- Do.
Obolella prima Whitfield [1884, pp. 142-143]. .................-...-..--- Lingulella prime.
Obolella sabrinze Callaway [1877, p. 669] ........-..---.---.------------- Acrotreta sabrine.

Deyviclsorn [EEE jos Mill]. dscescaccossnceocosssooccuSsae Do.

Tae yll gael Clemlie [EAS jo), WOB|oncoacscoceescescessaccsc IDO,

Obolella sagittalis Brogger [1882, p. 45]......-..---.----.----------------- Acrotreta sagittalis.

Davidson [1868, pp. 309-310]...................-.-.-.- Do.

Dawadsons pl Si“lesppac39—340 | -aeee eee eee ee ae Do.

Weiymalsorn [WER jos Aloe sssecosseecossaecoesoscassece Do.

eammanssony [Si/Gs spp 19-20) pease seen eeeeeeeee seen esas Do.

ILinmmenrssorn |G). [Os AAAS |o sasceoscescoescooaseessas Do.

Silla [WAKE 1, Zw |essceadaseosososcuuseqsesdocssous Do.

Obolella cf. sagittalis Wiman [1902, p. 66]...---.....--.---.-------------- Do.
Obolella sagittalis belti Davidson [1871, desc. of Pl. L, figs. 15-17]........./ Acrotreta belti.
Obolella? salteri Davidson [1868, p. 311]. -....-......-..--..------.------ Obolus (Broggeria) salteri.
ObolellajsalteniEloll|M865y on W02) See. se = 2 ee ee eee eee Do.
Obolella (?) salteri Matley [1902, pp. 139-140]..............-...-.....--- Do.
Obolella salteri Phillips [1871, p. 68]..---..--.-.---- soe Saeed Do.
Obolella salteri? Davidson [1866, pp. 61-62]....-....-..--..-...--.------ Do.
Obolella? scabrinze Walcott [1884b, Pl. I, fig. lc].............-----.----- Acrotreta sabrinz.
Obolella transversa Hartt [1868, p. 644]......-...--.---.--..---.---.---- Acrotreta sagittalis transversa.
Taleyattin USASh 1050-44 ee pear eoeeeseoeneas eo oascesosase Do.
Iekeynn, [SI fon ee Soe eeneeceoeeeuesecHeeascocsace Do.
\Weilkeouis [MMe ios US| boascosemcacssoccteseessseesnaes Do.
Obolella vermilionensis Walcott [new]--.---.--.------------------------- Obolella vermilionensis.
Obolella wirrialpensis Etheridge [1905, p. 248]............--.-.--.-------- Obolella wirrialpensis.
Obolella wirrialpensis calceoloides Etheridge [1905, p. 249]...........---- Do.
Oloollelia, Fo, GH WsMUborss [MGW O, 7D. W|o-ccoe = =ceosssecsecoce soasseessessesas Dicellomus politus.
Ii haves! MGC, jo), GHG]|--eebs-oscccncno sooescsoocueescncoes Do.
IBwilbiraves) (MAGA, JO. MMS poscassescossesesoncaesoesocrsoesese Do.
Obolella sp. (?) Bornemann [1891, p. 440].......-..--.------------------ Obolus? meneghinii.

Obolella sp. Shaler and Foerste [1888, pp. 27-28].....--..-..-.----------- Obolella atlantica.

72 CAMBRIAN BRACHIOPODA, »

Present reference.

Obolella (Acrotreta?) sagittalis Moberg and Segerberg [1906, p. 64]........- Acrotreta sagittalis.
Obolella (Glyptias) Walcott [1901, p. 675]-.-....................-......- Obolella (Glyptias).
Walcott [1908e, Pl. XI, and pp. 142 and 145].......... Do.
Obolella (Glyptias) favosa Walcott [1901, pp. 675-676]...........--........ Obolella (Glyptias) favosa-
Obolella (Kutorgina) Dall [1870, pp. 154 and 163].- Nae ... Kutorgina.
Obolella (Kutorgina) cingulata Billings [1861b, pp. & 9, fas, 8 amd 10]. .- Kutorgina cingulata.
Billings [1861b, p. 8, fig. 9].......-........ Rustella edsoni.
Billings [1861c, p. 948, figs. 347 and 349]... Kutorgina cingulata.
Billings [1861c, p. 948, fig. 348]............ Rustella edsoni.
Billings [1862e, p. 220, figs. 347 and 349]... Kutorgina cingulata.
Billings [1862e, p. 220, fig. 348]........-..- Rustella edsoni.
Obolella (Linnarssonia) pretiosa Dawson Cae pp- Bye! Peete Oct eee Acrotreta sagittalis.
Obolella (Orbicula) czelata Ford [1871, p. 33] -- ss-++-----------------Botsfordia celata.
Obolella (Orbicula?) crassa Ford [1871, p. 33]..................-.--..---- Obolella crassa.
Obolellus? phillipsi Roemer [1876, Pl. II, figs. 6a-d]...................... Micromitra (Paterina) phillips.
Obolus Dall [1870, pp. 154 and 162]...........................-....-2.--: Obolus.
Davidson [1853, pp. 135-136].-.....---.-.-.-.-------------------- Obolus (in part), O. (Acritis) (in part), and
5 O. (Mickwitzella) (in part).
Davidson [1866, p. 58]..--...-.-...-..--- Mccann ee ec tee eee Obolus.
MarvidsonyllS83.( oy ailS|| sae setae eee ery ce sen oe Do.
Bichwalldu[l829 sper 274 seem saute Seep yan ee raja eae need Do.
Bichwal del SG0ys pp 3924-925) eeasye ees een ey Are eee cee Obolus (in part), O. (Acritis) (in part) and
O. (Mickwitzella) (in part).
Hall and Clarke [1892a, pp. 242-243]. .........-..-----------:---- Obolus.
Hall and Clarke [1892b, pp. 558-559]............................. Do.
Hall and Clarke [1892c, pp. 80-81 and 337-339]...............---- Do.
awtionee, (IOAGY Top PRD PTE SUC eek ually aetna os lego) Do.
Matthews[l $92) pp .4oa44l eae ie hee cece eens Noes Do.
Matthey 9035 op-nkaoleeis cere Sesser sere oe ne ee eee sete eete Do.
Mire kewritiza [8925s To 5151-04 | eee ene yy oa eee Do.
Mickwitzs [896s ppm l=133) (1272129) [ese meme eee wel rene Do.
Wiorials [MBVe), joys BIDSAO||o. « c cos cbecsoccssenoawsoonenncessacsss Do.
@ehilenti[MS8i77 govt? Gil] Sapa ees eee sees eer ae ein at ene ee eae Do.
desVierneutl|plis45: soa 20d bree ere oe etn eee ete ere pesteete ro eee Do.
\Walleotits |[IEEEID. ad. ES -WNG||. so naosocacase cooccacasaseadeosases Do.
Welker MOON, joes GUAT é occa sdeesassessescoesscoonosasonse Do.
Walcott [1908e, Pl. XI, and pp. 142 and 144]._.................. Do.
Arties (M880 sei Osa| = away ayee eee eee i et Steyr LS pet oy eee a Do.
Obolus acadica Walcott [1905a, pp. 324-325]. .......--..--.--------.---- Obolus acadicus.
Obolus? advena Barrande [1879b, Pl. XCV, fig. Iv]...-..- sola iacat ARES ae eS Obolus? advenus.
Obolus zequiputeis Matthew [1902c, p. 94] .-...--...-..---.--..-------- Obolus selwyni.
Menninger |G; fs USD oc oa doeece=sescocdesndecceese Do.
Obolus anceps Walcott [1898b, pp. 388-389]. ...........-.---.---------- Obolus anceps.
Obolus antiquissimus Eichwald [1859, Pl. XX XVII, figs Cees wbibiiaaeutaat Obolus (Acritis) antiquissimus.
Eichwald [1860, pp. 928-929]. - Ee Mich See leet Do.
Obolusjapollinis Billings! [MS72ar pe 2S) sees sss see see see see = eee eee Obolus apollinis.
ByUIEERE SUAS, 105 BAOl|e occ occas ssocccoeenacdcsassees Do.
Davidson [1853, figs. 51 and 52, p. 136, and Pl. IX, figs.
DBOe DBA er ay aye Uae eRe te aee hag aie eee Do.
Davidson [1853, Pl. UX, fig. 285]. ..............2-----2:- Obolus (Acritis) antiquissimus.
Bich woallds[ie20 sp 274i] sue emer rcs eee ae een ee Obolus apollinis.
IBnelonsealol [MYO 70), WH so aakassescecoasaecsodsadssceane Do.
Bichival da[liS43bsyp 40 beenee =e epeea ee eee ee eee eee Do.
BichwaldalS60 spp 925-926) sees seen eee eee eee a= Do.
Gacelli [890 jspps21 22] eon sceee ese sere tee ee eee Do.
Hall and Clarke [1892a, figs. 247 and 248, p. 242]......--.- Do.
Hall and Clarke [1892b, figs. 247 and 248, p. 558]-...----- Do.
Iseulll gravel (ClewaKS |B, yo), Ol. 6 adsos soo-cuscescaesccece Do.
Kutorga [1848, pp. 251 and 252]-...-.....-.-....-.-.---- Do.
Matthew: [892) pps 4344] e oes ae eee eee Do.
Mielqvattizs | MSCS, joi. USBI. o coacsossecasdsoccsauscce= Do.
Moberg and Segerberg [1906, p. 65]...-...-----..-------- Do.
Morriss [i649 Spoil Gap eyacrtrs ncn Soslelecire sera ets Do.

Noetling [1883, p. 265]......-..--...-.-- Sao descnernese Do.

SYNONYMIC REFERENCES.

Present reference.

73

Obolus apollinis Roemer [1876, Pl. II, figs. 7a-c] .........-.-..---------- Obolus apollinis.
Roemer [1885, pp. 23-24 (270-271)]. .....-.------------- Do.
Selaeaieli: Mela, 7), BS). .secascesseecocsccessocaoe Bayi Do.
de Verneuil [1845, pp. 290-292]. .........-...-.--.----- Obolus apollinis (in part), O. apollinis

ingricus (in part), O. (Acritis) antiquis-
simus (in part), and O. (Mickwitzella)

siluricus (in part),

Walcott) [S98 Plt XexeVal hes':3—6 pre eee eee Obolus apollinis.
Westergard [1909, p. 56].-....-.-- ERE e eee sae wane Do.
Zittel [1880, figs: 488a-c, p. 664]. ....-.-.:-.------------ Do.
Zittel [1880, fig. 488d, p. 664].......-- Al Ya Ue Obolus apollinis quenstedti.
Obolus apollinis ingricus Mickwitz [1896, pp. 137-140]... .....-..--.----- Obolus apollinis ingricus.
Obolus apollinis maximus Mickwitz [1896, pp. 140-143].........----..---- Obolus apollinis maximus.
Obolus apollinis quenstedti Mickwitz [1896, pp. 143-145]. .........-.-.-- Obolus apollinis quenstedti.
Obolus appolinus? Owen [1852, p. 501). ...-......--.....--..----------- Dicellomus politus.
Obolus? bohemicus Barrande [1879b, Pl. CII, figs. vit: 1-3]... -...-..-...-Acrothele bohemica.
Obolus bretonensis Matthew [1902c, p. 95] +...........-----.------------ Obolus (Paleobolus) bretonensis.
Obolus celatus orbiculatus Moberg and Segerberg [1906, p. 65]. ..-..-.---.! Obolus (Schmidtia) celatus.
Westergard [19095 p.56]52-2------2---4-----2- Do.
Vain [12,195 Olle c oc segsoascceaceseasen5= Do.
Obolus? complexus Barrande [1879b, Pls. XCV, CXI, CXIII, and CLII]..Obolus complexus.
Obolus discus Matthew [1902c, p.94]...-..-..-..-.----.------++-++---- Lingulella triparilis.
Obolus eichwaldi Mickwitz [1896, pp. 154-155]. ......--.---.---.------- Obolus eichwaldi,
Obolus elegans Mickwitz [1896, pp. 157-158]... .......--.--..----------- Obolus elegans.
Obolus ella Matthew [1902c, pp. 96 and 110]......-....---....--------- Obolus (Westonia) ella.
Obolus? inflatus Westergard [1909, p. 76] .......-.--.------------------- Obolus? inflatus.
Obolus ingricus Eichwald [1829, p. 274]..........-../....-..------------ Obolus apollinis ingricus.
Hichwald [1848b, p. 140-141]......1..........-..---.---- Do.
Bichwalds [il860s ppy926=92i7l||eeaess=sees eee eee eee see Do.
von Leuchtenberg [1843, p. 16].......-.--....---...---- Do.
Obolus ismene Walcott [1905a, p. 325].......-..-..-.-.-----.---------- Obolus ismene.
Obolus labradoricus Billings [1861b, p. 6].....--...---.-.--------------- Micromitra (Paterina) labradorica.
TewillomaVess [MEGNC, Ts CAGE o esasseasscoscegesscssascan< Do.
Ballin est [S62es pow 218) es eta ete ee Do.
Tesi Douay MGB, TO. Aeilo 6 a soo cadoecauscssscnoescasacs Do.
Obolusilens Matthew) [1902c) pis] 22222-52222 seen eee ese Obolus (Palzeobolus) bretonensis lens.
Obolus lens-primus Matthew [1902c, pp. 94-95]. .......--.---.--.------- Do.
Obolus loperi Walcott [1898c, pp. 389-390] ...........---.--.---.-------- Obolus loperi.
Obolus mcconnelli Walcott [1908c, Pl. I, fig. 2].........-..-------------- Obolus mcconnelli.
Walcot: M@Osie. IAL Hy ie, Al], ss -ccescassesensoscene Obolus septalis.
Obolus mcconnelli decipiens Walcott [new] ......---.------------------- Obolus mcconnelli decipiens.
Obolus? major Matthew [1890, p. 155]... .-....-..--...-.....---..--.--- Rustella? major.
Obolus matinalis? Walcott [1905a, p. 325]. -.....-...-..-------.--------- Obolus matinalis?.
Obolus membranaceous Walcott [1908d, p. 61]......----..-----.--------- Obolus membranaceus.
Obolus (?) meneghini Walcott [1901, p. 684]..................-.........- Oboius? meneghinii.
Obolus mickwitzi Walcott [1898b, pp. 386-387]............-.------------ Obolus mickwitzi.
Obolus? minimus Barrande [1879b, Pl. XCV, figs. m: 1-5] --.....-...-.--- Acrotreta? minima.
Obolus minimus Walcott [1905a, pp. 325-326].........--.-.-.-------.---- Obolus minimus.
Obolus? minor Barrande [1868a, p. 105]....-.--.-.......------------------ Obolus? minor.
Barrande [1868b, p. 693].--------------- OE oR Ue ey PEN ATG Do.
Obolus? monilifer Linnarsson [1871, pp. 9-10]...---.--..------------------ Mickwitzia monilifera.
Obolus? murrayi Billings [1865b, p. 362]............-..-..-.------------- Obolus? murrayi.
Obolus namouna Walcott [1898b, p. 390]....---..-- Je elsiea elem eras er oe Obolus namouna.
Obolus nundina Walcott [1905a, p. 326]. -...-- Giga ES ger ose fue ae cee Obolus nundina.
Obolus obscurus Walcott [1905a, p. 326]....--.....---------------------- Obolus obscurus.
Obolus obtusus? Moberg and Segerberg [1906, p. 65].....-..---.-..-------- Oboius (Schmidtia) obtusus.
Wicsucmeeinel |MQOG), > Bil |-oocsncpccesceScasossossesessa5e6 Do.
Wyairaann [IGOR (Os GBlleseceasscesocacecooorsccaoeceesseste Do.
Obolus? palliatus Barrande [1868a, pp. 104-105, fig. 64]........-.-.------- Obolus? bavaricus.
Barrande [1868a, pp. 104-105, fig. 65].......-.--..---.-- Obolus? palliatus.
Barrande [1868b, p. 693, fig. 64].---.-..---- ENC ae Obolus? bavaricus.

Barrande [1868b, p. 693, fig. 65]...........-.--.-.--..-- Obolus? palliatus.

74 CAMBRIAN BRACHIOPODA.

Present reference,
Obolus pandemia Walcott [1898b, p. 388].......--..-.-.......-.--.------- Obolus pandemia.
Obolus panderi Mickwitz [1896, pp. 149-151]. ......- cite heated ee ee Obolus panderi.
Obolus parvus Walcott [1908d, pp. 61-62]................-....-..---....- Obolus parvus.
Obolus pectenoides Whitfield [1875, p. 103]...........-...--..--.-------- Dicellomus pectenoides.
Obolus? pectenoides Whitfield [1880, pp. 338-339]................-....-.--Dicellomus pectenoides.
Obolus pheres Walcott [1905a, p.'328]...-.-.......--5-----5:--222--2----- Obolus pheres.
Obolus pristinus Matthew [1895a, pp. 121-122]..........-..............-- Trematobolus pristinus.
Werner? |MSUPtes 19), Coll sesoe ssoéuenoucsnaosadosccdasense Do.
Obolus? pulcher Hall and Clarke [1892c, pp. 81 and 183]........-.......-. Botsfordia pulchra.
Obolus pulcher Matthew [1889, p. 306]:---2--.2---2----222..-.2---.2--2- Do.
Matthews [S90 spp silo S50) basse eee areas ase ea eee Do.
Obolus quenstedti Hall and Clarke [1892a, p. 243].........................Obolus apollinis quenstedti.
Hall and Clarke [1892b, p. 559]. .......-.-.../.---..-- Do.
Hall and Clarke [1892c, p. 339].:......--..-..---.--.- Do.
Martthewall l903%i a alt2 0) Raeee eres seer spe ae) ere Do.
Mii clewatzh [ISO 24s po G2] easeeoe cee se Trees Do.
Wyetkooiits, [DUES 10), Bell ousosdascasesocanesuosceese see ‘ Do.
Obolus refulgens Matthew [1892, pp. 44-45].............--....----...---- Obolus refulgens.
Marithewal [902 chip9 6 aeeepes sees eee eee eee an ae Do.
Obolus? refulgens Mickwitz [1896, pp. 23-24]..........-....2.-...2..---.-- Do.
Obolus rhea Walcott [1898b, pp. 387-388]...........----..--------------- Obolus rhea.
Obolus? rokitzanensis Barrande [1879b, Pl. CX XV i FRE eciete ea ay hoes heaps Obolus rokitzanensis.
Obolus salteri Brégger [1882, pp. 44-45]... -e--------------------------Obolus (Bréggeria) salteri.
Obolus? salteri Dall [1870, p. 163]...-..--..---- Ra ee ER eRe, Do.
Mick witza[1896sspailOleetee mecca cones e aes ase ce Do.
Obolus schmidti Mickwitz [1896, pp. 152-154]............... Bet Meee Sees crs Obolus schmidti.
Obolus shensiensis Walcott [1905a, p. 327]..-..--.--..----..-..----------- Obolus shansiensis.
Obolus siluricus Eichwald [1843a, pp. 7-8]...--..-..--..--.----+---------- Obolus (Mickwitzella) siluricus.
Hichwald [1859, Pl. XX XVII, figs. 6 and 7a-b]......-..-- Do.
Bichwald [1860, pp. 927-928]............-.-------------- Do.
Mickwitz! [1892s pNG0les2 soe ce ee Do.
Soimide (MSGi pa cs] eres wee eee Sone pS ae Do.
SCHimiG Ts SCM pea mee awe tree ees Ree ee a Do.
Srewarbenelaien [PERG To, Olas soasse2scecscosascsesase5000 Obolus (Acritis) antiquissimus.
Obolus smithi Walcott [1908d, pp. 62-63, Pl. VII, fig. 9a] ...............- Obolus smithi.
Walcott [M908d, Pl. VAT, fig. 9}e.--222-- =. - Bee RR ere Micromitra (Paterina) major.
Obolus tetonensis Walcott [1901, p. 684].............---....---+--------: Obolus tetonensis.
Walcott] 905 apr oil beer ane else nee eser ae seeeeer= Do.
Obolus tetonensis leda Walcott [1908d, p. 63]........-....-.---.-..-..--- Obolus tetonensis leda.
Obolus tetonensis ninus Walcott [1905a, p. 328]...............-...-..--.- Obolus tetonensis ninus.
Obolus torrentis Matthew [1902c, p. 94] .......-....--....-.--.----------- Obolus? torrentis.
Matthew; [1903p eG) Seseeae ee eee sek seein emer rae Do.
Obolus triangularis Mickwitz [1896, pp. 145-147]......-.................-- Obolus triangularis.
‘ Moberg and Segerberg [1906, p. 65]..................-- Do.
Wesvenepingl (MOOD. jo, BS] asssascsaccssnconecaasaccsase Do.
Obolus triangularis inornatus Mickwitz [1896, pp. 148-149]................. Do.
Obolus triparilis Matthew [1902c, p. 94]..--.-...-.....-....--.-.-......-- Lingulella triparilis.
Obolus volborthi Mickwitz [1896, pp. 155-157]........-.......-....-..-.- Obolus volborthi.
Obolus wortheni Walcott [1908d, pp. 63-64]...........---..-------------- Obolus wortheni.
Obolus? zoppi Walcott [1901, pp. 684-685]...........-....--..--.-.-..---- Obolus? zoppi.
Obolus sp. Kayser [1876, pp. 9-10]..............-. JOSS RIRS ek ease eae Obolus? sp. undt.
Obolus? sp. Kjerulf [1873, p. 83, figs. 10 and 1]].-............-.........-- Obolella mobergi?.
Obolus (?) sp. indet. Linnarsson [1876, p. 16].......-.....-..-.......-.-- Obolus sp. undt. g.
Obolus (Acritis) Mickwitz [1896, pp. 205-206]..............-.-..-..----.- Obolus (Acritis).
SWalcotts [MO OlepmG Sears ores eyes ee ern pee re Do. :
Walcott [1908e, Pl. XI, and pp. 142 and 144] ...........- Do.
Obolus (Acritis) antiquissimus Mickwitz [1896, pp. 206-213]......-......-- Obolus (Acritis) antiquissimus.
Obolus (Acritis) antiquissimus ventrosus Mickwitz [1896, pp. 213-214]... - Do.
Obolus (Acritis?) rugatus Walcott [1901, p. 694]...........-.......--.-.-- Obolus (Acritis?) rugatus.
Obolus (Botsfordia) Matthew [1891, p. 148]...............-. beseseoseases Botsfordia.
Wirrniney (MERE fo. GBlscstasecascecscacdeooesomssoaas> Do.
Obolus (Botsfordia) pulcher Matthew [1891, p. 148]...................---- Botsfordia pulchra.

Matthew [1892, pp. 62-63]...-......---------- Do.

‘

nt et ie

“I
on

SYNONYMIC REFERENCES.

Present reference.

Obolus (Botsfordia) pulcher Matthew [1902c, p. 95]....--.---------------- Botsfordia pulchra.
Obolus (Botsfordia) pulchra Matthew [1894, pp. 90-91]...-...........--.-- Do.
Matthew [1895a, pp. 115-121]...............-. Do.
Obolus (Bréggeria) Walcott [1902, p. 605]..........-.....-.--------------- Obolus (Bréggeria).
Walcott [1908e, Pl. XI, and pp. 142 and 144]........-- Do.
Obolus (Bréggeria) salteri Moberg and Segerberg [1906, p. 64]....-.---.--- Obolus (Bréggeria) salteri.
Walcott [1902, pp. 605-606] ................---- Do.
Obolus (Bréggeria) salteri var.? Westergard [1909, p. 56]...--.---.--------- Do.
Obolus (Eoobolus) Matthew [1903, pp. 185-136].--.-..---...--.----------- Obolus (in part) and Lingulella (in part).
Obolus (Eoobolus) discus Matthew [1903, pp. 188-139]...-.----------------- Lingulella triparilis.
Obolus (Eoobolus) triparilis Matthew [1903, pp. 136-187]. ..-.--.-.------- Do.
Obolus (Buobolus) Mickwitz [1896, pp. 129 and 133]...........-.--------- Lingulella (in part) and Obolus (in part).
Obolus (Fordinia) Walcott [1908d, pp. 64-65]...........-.-.------------- Obolus (Fordinia).
Walcott [1908e, Pl. XI, and pp. 142 and 144].....-.....- Do.
Opolus (Fordinia) gilberti Walcott [1908d, p. 65]..--.----.--------------:- Obolus (Fordinia) gilberti.
Obolus (Fordinia) perfectus Walcott [1908d, pp. 65— sa Sr eRSS Ae anaes ey Cee Obolus (Fordinia) perfectus.
Obolus (Leptembolon) Mickwitz [1896, p. 199]-- Sake ...-Lingulella (Leptembolon).
Walcott [1908e, Pl. XI, eae pp- 142 ain 144]. aes soe Do.
Obolus (Leptembolon) linguleeformis Mickwitz [1896, pp. 200-204] ........ Lingulella (Leptembolon) lingulzeformis.
Obolus (Leptembolon) linguleeformis solidus Mickwitz ee. pp. 204— Coe Do.
Obolus (Lingulella) Walcott [1898b, pp. 390-392] -. site miiae ..----Lingulella.
Walkooit MSO, jo. G83]| cos 4 cosccopcocusdoccocaonsessode Do.
Obolus (Lingulella) acutangulus Walcott [1898b, pp. 393 and 394, Pls.
PRONGV Ali iaan Ae NGNOV UN Epes a oe ee ae 2 dea Saree eae Lingulella acutangula.
Obolus (Lingulella) amplus Walcott [1898b, pp. 392 and 394, Pl. XX VIII]. .-Lingulella ampla.
Obolus (Lingulella) argutus Walcott [1898b, p. 396]. ....-..-.------------ Lingulella arguta.
Obolus (Lingulella) atavus Walcott [1902, pp. 609-610]........-..--..---- Lingulella atava.
Obolus (Lingulella) auga Walcott [1898b, pp. 396-397]. .....-..--..---.---- Lingulelia auga.
Obolus (Lingulella) bellulus Matthew [1903, p. 205]......-..-....--.------ Lingulella bellula.
Wralkeorit |[MESto, TOs Bsil|_caceaccescccaccssanas Do.
Obolus (Lingulella) bellus Matthew [1903, p. 204]............-..-..---.-- Lingulella bella.
Walcott [1898b, pp. 397-398]. ..............--- Do.
: Walcott [1901, pp. 685-687]..........-.--.....--Lingulella bella (in part), L. concinna (in
; part), and L. lens (in part).
Obolus (Lingulella) bicensis Walcott [1901, p. 688]...-...---..-..--------- Botsfordia celata.
Obolus (Lingulella) bornemanni Walcott [1901, pp. 687—-688]......-...--:- Lingulella bornemanni.
Obolus (Lingulella) canius Walcott [1902, pp. 610-611]..................- Lingulella cania.
Obolus (Lingulella) celatus Walcott [1898b, Pl. X XVI, figs. 1 and 2]....-. Obolus (Schmidtia) celatus.
Obolus (Lingulella) chinensis Walcott [1905a, pp. 328-329].......-..-..-..- Obolus chinensis.
Obolus (Lingulella) chuarensis Walcott [1898b, p. 399]...........-..-.---- Obolus (Westonia) chuarensis.
Obolus (Lingulella) collicia Walcott [1902, p. 610]........--.........-.-..-- Lingulella collicia.
Obolus (Lingulella) concinnus Walcott [1902, pp. 608-609].......-..--...-- Lingulella concinna.
Obolus (Lingulella) cuneolus Walcott [1899, p. 443]......-.....-..-.-- ....-Lingulella cuneola.
Obolus (Lingulella) damesi Walcott [1905a, p. 329]........-......--..--.- Obolus damesi. (See Lingulella damesi,
p. 489.)
Obolus (Lingulella) davisii Walcott [1898b, pp. 394 and 395]............-. Lingulella davisi.
Obolus (Lingulella) desideratus Walcott [1898b, pp. 399-400] ....-........- Lingulella desiderata.
Walcott [1899, pp. 445-446, Pl. LX, fig. 2]. . Do.
Walcott [1899, pp. 445-446, Pl. LX, fig. 2a] -Obolus rotundatus.
Obolus (Lingulella) discoideus Walcott [1901, p. 673] ........-..-.-..-.-- Obolus discoideus.
Obolus (Lingulella) dubius Walcott [1898b, p. 401]-- ane ...------Lingulella dubia.
Obolus (Lingulella) ella Walcott [1898b, Pl. XXVIII, He, 5-1 Sa. aie pera oe Obolus (Westonia) ella.
Obolus (Lingulella) ellsi Walcott [1898b, p. 402]. ..-...-......-..-------- Lingulella ellsi.
Obolus (Lingulella) euglyphus Walcott [1898b, pp. 402-403]. ...........-- Obolus (Westonia) euglyphus.
Obolus (Lingulella) fragilis Walcott [1898b, p. 404]....-........-...------- Obolus fragilis.
Obolus (Lingulella) franklinensis Walcott [1898b, pp. 404-405]...........-. Lingulella franklinensis.
Obolus (Lingulella) fuchsi Walcott [1905a, p. 332]..........-.-.-..-------- Lingulella fuchsi.
Obolus (Lingulella) gemmulus Walcott [1901, p. 673]. -..-........-...-.-- Lingulella ferruginea.
Obolus (Linguleila) hayesi Walcott [1898b, pp. 405-406]...................Lingulella hayesi.
Obolus (Lingulella) helena Walcott [1898b, p. 406].......--......-...-...- Lingulella helena.
Obolus (Lingulella) ino Walcott [1898b, pp. 406-407].......-............-- Lingulella ino.
Obolus (Lingulella) isse Walcott [1905a, p. 330]...-.....--...-.---------- Lingulella isse.

Obolus (Lingulella) lamborni minimus Walcott [1898b, p. 407]......------- Obolus lamborni minimus.

76 CAMBRIAN BRACHIOPODA:

Obolus (Lingulella) lens Walcott [1902, pp. 606-607]
Obolus (Lingulella) leos Walcott [1898b, pp. 407-408]
Obolus (Lingulella) lineolatus Walcott [1898b, pp. 408-409]
Obolus (Lingulella) linnarssoni Walcott [1901, p. 688]
Obolus (Lingulella) mzera Walcott [1899, p. 443]
Obolus (Lingulella) matinalis Walcott [1899, p. 443]......-.....-....-----
Obolus (Lingulella) mosia osceola Walcott [1898b, p. 409]
Obolus (Lingulella) nanno Walcott [1898b, p. 409]
Obolus (Lingulella) orus Walcott [1905a, p. 330].-..........--..--..------
Obolus (Lingulella) oweni Walcott [1898b, p. 410]
Obolus (Lingulella) pelias Walcott [1905a, pp. 330-331]
Obolus (Lingulella) perattenuatus Walcott [1899, p. 443]
Obolus (Lingulella) phaon Walcott [1898b, pp. 410-411]
Obolus (Lingulella) pogonipensis Walcott [1898b, pp. 411-412]
Obolus (Lingulella) prindlei Walcott [1898b, p. 412]
Obolus (Lingulella) punctatus Walcott [1898b, pp. 412-413]
Obolus (Lingulella) quadrilateralis Walcott [1905a, p. 331]
Obolus (Lingulella) randomensis Walcott [1901, pp. 688-689]
Obolus (Lingulella) rogersi Walcott [1898b, pp. 413-415]

Present reference.
Lingulella lens.
Lingulella leos,
Lingulella lineolata.
Lingulella linnarssoni.
Obolus meera.

.Obolus matinalis.

Lingulella mosia osceola.
Lingulella nanno.

. Lingulella ora.

Lingulella oweni.

Obolus meconnelli pelias.
Lingulella perattenuata.
Lingulella phaon.

Lingulella pogonipensis.

Obolus prindlei.
Lingulella punctata.
Lingulella quadrilateralis.
Lingulella randomensis.
Obolus (Westonia) rogersi.

Obolus (Lingulella) rotundatus Walcott [1898b, p. 415].............---..- Obolus rotundatus.

Obolus (Lingulella) schmalenseei Walcott [1902, p. 605]
Obolus (Lingulella) schucherti Walcott [1901, pp. 689-690]
Obolus (Lingulella) septalis Walcott [1905a, p. 331]
Obolus (Lingulella) siemiradzkii Walcott [1901, pp. 690-691]
Obolus (Lingulella) similis Walcott [1898b, pp. 415-416]
Obolus (Lingulella) sinoe Walcott [1898b, pp. 416-417]
Obolus (Lingulella) spatulus Walcott [1902, p. 607]

Obolus schmalenseei.
Lingulella schucherti.

Obolus septalis.

Lingulella siemiradzkii.
Lingulella similis.

Obolus sinoe.

Lingulella (Lingulepis) spatula.

Obolus (Lingulella) tarpa Walcott [1898b, pp. 417-418]....-..-....-.----- Lingulella tarpa.

Obolus_(Lingulella) upis Walcott [1905a, pp. 331-332].......-....--.------
Obolus (Lingulella) wanniecki Walcott [1905a, p. 332].........-....---.--
Obolus (Lingulella) welleri Walcott [1902, p. 608]
Obolus (Lingulella) willisi Walcott [1898b, pp. 418-419].-...........---.--
Obolus (Lingulella) winona convexus Walcott [1901, p. 691]
@Obolus (Lingulella) zetus Walcott [1898b, p. 419]
Obolus (Lingulepis) Walcott [1899, pp. 443-444]

Walcott [1901, p. 683]......---.-------
Obolus (Lingulepis) acuminatus Walcott [1899, p. 443].........--.-...-----
Obolus (Lingulepis) acuminatus meeki Walcott [1899, p. 444]
Obolus (Lingulepis) eros Walcott [1905a, p. 333]
Obolus (Lingulepis) gregwa Walcott [1901, pp. 692-694]

Obolus (Lingulepis) primus Walcott [1901, p. 673]
Obolus (Lingulepis) rowei Walcott [1905a, p. 334]
Obolus (Lingulepis) sp. undt. Walcott [1906, pp. 567-568]

Obolus (Lingulobolus) Walcott [1901, p. 683]

Walcott [1908e, Pl. XI, and pp. 142 and 144]
Obolus (Lingulobolus) affinis Walcott [1898a, p. 327]
Obolus (Lingulobolus) spissus Walcott [1898a, p. 327]
Obolus (Lucina) antiquissimus Eichwald [1843b, pp. 142-144]

Obolus (Mickwitzella) Walcott [1908d, p. 70]

Walcott [1908e, Pl. XI, and pp. 142 and 144]

Obolus (Monobolina) refulgens Matthew [1902c, p. 98]
Obolus (Palzobolus) Walcott [1908e, Pl. XI, and pp. 142 and 144]
Obolus (Paleeobolus) lens Matthew [1903, pp. 144-146]
Obolus (Palzeobolus) lens longus Matthew [1903, pp. 146-147]
Obolus (Schmidtia) Mickwitz [1896, p. 158]...........--.---
Walcott [1901l, p. 683]...-.-.--.--------

Walcott [1908e, PI. XI, and pp. 142 and 144]

Obolus (Schmidtia) acuminatus Mickwitz [1896, pp. 179-183]...........---
Obolus (Schmidtia) acuminatus alatus Mickwitz [1896, pp. 183-184]

Lingulella upis.

- Lingulella wanniecki.

Lingulella welleri.

Obolus willisi.

Lingulella winona convexa.

Obolus zetus.

Lingulella (Lingulepis).

Do.

Lingulella (Lingulepis) acuminata.

Lingulella (Lingulepis) acuminata meeki_

Lingulella (Lingulepis) eros.

Lingulella atava (in part), L. tumide
(in part), L. cania (in part), L. (Lin-
gulepis) gregwa (in part), and L. (L.)
exigua (in part).

Lingulella prima.

Lingulella (Lingulepis) rowei.

Lingulella (Lingulepis ?) sp. undt.

Obolus (Lingulobolus).

Do.

Obolus (Lingulobolus) affinis.

Obolus (Lingulobolus) spissus.

Obolus (Acritis) antiquissimus.

Obolus (Mickwitzella).

Do.

Obolus refulgens.

Obolus (Palzeobolus). ;

Obolus (Palezeobolus) bretonensis lens.

Do.
Obolus (Schmidtia).
Do.
Do.
Obolus (Schmidtia) acuminatus.
Do.

SYNONYMIC REFERENCES. a

Present reference.
Obolus (Schmidtia) acuminatus humeratus Mickwitz [1896, pp. 184-186]. ..Obolus (Schmidtia) acuminatus.
Obolus (Schmidtia) acuminatus subtriangularis Mickwitz [1896, pp. 186-

OT Cet tenes Ae Arete RR CRS Sir MMR aE RG Net Tin 2s es) (ele area Do.
Obolus (Schmidtia) celatus Mickwitz [1896, pp. 159-163].......-..-------- Obolus (Schmidtia) celatus.
Obolus (Schmidtia) celatus orbiculatus Mickwitz [1896, pp. 163-165]. ..-..- Do.
Obolus (Schmidtia) celatus preecisus Mickwitz [1896, pp. 166-167] --...--- Do.
Obolus (Schmidtia) crassus Mickwitz [1896, pp. 187-193]..........--------- Obolus (Schmidtia) crassus.
Obolus (Schmidtia) crassus angulatus Mickwitz [1896, pp. 193-194]......-- Do.
Obolus (Schmidtia) obtusus Mickwitz [1896, pp. 167-171].....-.---------- Obolus (Schmidtia) obtusus.
Obolus (Schmidtia) obtusus acutus Mickwitz [1896, pp. 172-173]....------ Do. :
Obolus (Schmidtia) obtusus ellipticus Mickwitz [1896, pp. 177-178].------- Do.
Obolus (Schmidtia) obtusus extenuatus Mickwitz [1896, pp. 178-179]....-- Do.
Obolus (Schmidtia) obtusus latus Mickwitz [1896, pp. 174-175]....-------- Do.
Obolus (Schmidtia) obtusus longus Mickwitz [1896, pp. 171-172].-.-.-.--- Do.
Obolus (Schmidtia) obtusus minutus Mickwitz [1896, pp. 175-177]....----- Do.
Obolus (Thysanotos) Mickwitz [1896, pp. 194-195]......-..--.------------ Obolus (Mickwitzella).
Obolus (Thysanotos) siluricus Mickwitz [1896, pp. 195-199]...........----- Obolus (Mickwitzella) siluricus.
Obolus (Lhysanotus)) Walcott (1901, p. 683]..-.-..--.-.--.--------------- Obolus (Mickwitzella).
Obolus (Westonia) Walcott [1901, pp. 683 and 691]........-.--.----.----: Obolus (Westonia).
Walcott [1908e, Pl. XI, and pp. 142 and 144]..........-. Do.
Obolus (Westonia) alandensis Walcott [1905a, p. 334]........-.-.-.-.----- Obolus (Westonia) alandensis.
Obolus (Westonia) aurora Walcott [1901, p. 691]....-.....-----.----------- Obolus (Westonia) aurora.
Obolus (Westonia) baltica Walcott [1905a, p. 334].........-.-------.----- Obolus (Westonia) balticus.
Obolus (Westonia) blackwelderi Walcott [1905a, p. 335].......-..-.------- Obolus (Westonia) blackwelderi.
Obolus (Westonia) bottnica Walcott [1905a, pp. 335-336]--...--..----.----- Obolus (Westonia) bottnicus.
Obolus (Westonia) chuarensis Walcott [1901, p. 691]......-.....-.--------- Obolus (Westonia) chuarensis.
Obolus (Westonia) dartoni Walcott [1908d, p. 67].-...-.....-.--.---------- Obolus (Westonia) dartoni.
Obolus (Westonia) ella Walcott [1901, p. 691]..--..-.--.-.--.------------ Obolus (Westonia) ella.
Obolus (Westonia) ella onaquiensis Walcott [1908d, pp. 67-68]...-...------ Obolus (Westonia) ella onaquiensis.
Obolus (Westonia) elongatus Walcott [1908d, p. 68]............-...-.------ Obolus (Westonia) elongatus.
Obolus (Westonia) escasoni Walcott [1901, p. 691].-........-..------------ Obolus (Westonia) escasoni.
Obolus (Westonia) euglyphus Walcott [1901, p. 691]...-....---..--------- Obolus (Westonia) euglyphus.
Obolus (Westonia) finlandensis Walcott [1902, pp. 611-612]............-.- Obolus (Westonia) finlandensis.
Obolus (Westonia) 1phis Walcott [1905a, p. 336]......-...--.--.---------- Obolus (Westonia) iphis.
Obolus (Westonia?) lamellosus Walcott [1901, p. 691].......---...-------- Obolus (Westonia?) lamellosus.
Obolus (Westonia) notchensis Walcott [1908d, p. 69]......-...--.---.---.-- Obolus (Westonia) notchensis.
Obolus (Westonia) rogersi Walcott [1901, p. 691]......--.----------------- Obolus (Westonia) rogersi.
Obolus (Westonia) stoneanus Walcott [1901, p. 691]......----.-.---.------ Obolus (Westonia) stoneanus.
Obolus (Westonia) themis Walcott [1905a, pp. 336-337]....-......--------- Obolus (Westonia) themis.
Obolus (Westonia) wasatchensis Walcott [1908d, pp. 69-70]....--..------- Obolus (Westonia) wasatchensis.
Obolus (Westonia) wimani Walcott [1905a, p. 337]...---..--...------------ Obolus (Westonia) wimani.
obscura [Billingsella], Walcott [1905a, p. 239]............--...-----..----- Billingsella obscura.
obscurus [Obolus], Walcott [1905a, p. 326]......-.-.--------------------- Obolus obscurus.
obtusus? [Obolus], Moberg and Segerberg [1906, p. 65].--......------------ Obolus (Schmidtia) obtusus.
Wesieustine! [IGOS), 10; Bil|s--22--ce22a200c0s05c00c00c590- Do.
VWitimngin [02 jo, GB|-s---cscosceccorsoszcsececseeczees Do.
obtusus [Obolus (Schmidtia)], Mickwitz [1896, pp. 167-171]..-.-.--.--.-- Do.
obtusus acutus [Obolus (Schmidtia)], Mickwitz [1896, pp. 172-173].-...-- Do.
obtusus ellipticus [Obolus (Schmidtia)], Mickwitz [1896, pp. 177-178].---- Do.
obtusus extenuatus [Obolus (Schmidtia)], Mickwitz [1896, pp. 178-179} .-. Do.
obtusus latus [Obolus (Schmidtia)], Mickwitz [1896, pp. 174-175]....--.-- Do.
obtusus longus [Obolus (Schmidtia)], Mickwitz [1896, pp. 171-172]. .---..-.- Do.
obtusus minutus [Obolus (Schmidtia)], Mickwitz [1896, pp. 175-177]. ---- - Do.
occidens [Mickwitzia], Walcott [1908d, p. 54]....-.....-.--.-..---------- Mickwitzia occidens.
celandica [Acrotreta], Westergard [1909, p. 76]....-..-.------------------/ Acrotreta celandica.
onaquiensis [Obolus (Westonia) ella], Walcott [1908d, pp. 67-68].-.....--- Obolus (Westonia) ella onaquiensis.
ophirensis [Acrotreta], Walcott [1902, pp. 591-592] -..-.-.-.--.---..------ Acrotreta ophirensis.
ophirensis [Acrotreta cf.], Walcott [new]..---.-----.-------------------- Acrotreta cf. ophirensis. .
ophirensis [Iphidella pannula], Walcott [1905a, p. 306]-....-.-.-.-------- Micromitra (Iphidella) pannula ophirensis.
ophirensis descendens [Acrotreta], Walcott [1908d, p. 95]..--.-.----.------ Acrotreta ophirensis descendens.
ophirensis rugosus [Acrotreta], Walcott [1902, p. 592].......-...------.--- Acrotreta ophirensis rugosa.

ora [Micromitra (Paterina) stissingensis], Walcott [new]........---.------ Micromitra (Paterina) stissingensis ora.

78 CAMBRIAN BRACHIOPODA.

Present reference.

Orbicella Dall [S77 spe oOl] seers es cree ee eer eel Keyserlingia (in part).

Dana; [L846] cs Pee es oe. Se en ee ee Does not equal Keyserlingia.

Haillvane)\ Clarke [i'892a- go 9254) peaseeee nae eae ae ees Keyserlingia.

iHallvand Clarke) [1892 sips5 70] sarees seeeeeeee san see eer Do.

Gh Or onteaai | MEO) 101 AO aesotasedecboacasccooduoneowseesncscaas Do.
Orbicella buchi Hall and Clarke [1892a, p. 254]..-......................-- Keyserlingia buchi.

Gl'Orelonsiany |[SI0), 1. AD) sees s- sscscsacosssocsessesocc5cee Keyserlingia buchi (in part).
OxbiculaidenVerne ml) [845% ph 288] seeasee ee eee eee eee ee eee Keyserlingia.
Orbicula buchi de Verneuil [1845, pp. 288-289]...............-..-..----- Keyserlingia buchi.
Oxrbicnlareze| arabs ela aS Aero 20 0) ene ase eee Botsfordia ceelata.
(Orbicula) czelata [Obolella], Ford [1871, p. 33]. -..--.........-.-...---- Do.
Oxbiculayerassa se alll (S472) p50290)| Pesan eee see eee ae ee Obolella crassa.
(Orbicula?) crassa [Obolella], Ford [1871, p. 33].-..........-..-..---.---- Do.
Oxbiculayprmial@wenl|li8525 ps pScllesseseeeseee ose eeesee seen oeee eee eee Obolus matinalis.
(Orbicula) primzeva [Discina], de Verneuil and Barrande [1860, p. 532]-..Acrothele primzva.
orbiculatus [Obolus celatus], Moberg and Segerberg [1906, p. 65]-...--..-- Obolus (Schmidtia) celatus.
Westergard [1909, p. 56]..-...--..--..---.-- a) 1DY0),
\Wiyatiane ian [OO jo)s\PAllecosasocsssacossooedadsue Do.

orbiculatus [Obolus (Schmidtia) celatus], Mickwitz [1896, pp. 163-165]. - - - Do.
Orbiculoidea Hall and Clarke [1892c, pp. 120-137] .....-....-........-..- Orbiculoidea.

AOnb Tem yrs Set M ee VN veto aye cee ea ese Do.

Walcott [1908e, Pl: XI, and pp. 142 and 147]............... Do. ;
Orbiculoidea pileolus Hall and Clarke [1892c, p. 137]..-.......-....---.-- Orbiculoidea pileolus.
ordovicensis [Lingula?], Moberg and Segerberg [1906, p. 63].-.-...--.----- Lingulella lepis.
orientalis [Billingsella], Hall and Clarke [1892c, p. 230]. . ...-.-.--------- Billingsella orientalis.

Walcott [1905a, pp. 239-240]...........-....---.-- Do.
orientalis [Iphidella labradorica], Walcott [1905a, pp. 305-306]..........-- Micromitra (Paterina) labradorica orientalis.
orientalis [Orthisina], Walcott [1886b, p. 120].............--..--- te eee Billingsella orientalis.
Well@orni: [Oia io), GUS cesccoceceseceorocesoceose Do.
Winitireld} 1 SS45ipp e442 ess hua a sas sees epee aunts Do.
orientalis [Syntrophia], Walcott [1905a, p. 292]...-..-..---..-..---------- Huenella orientalis.
orientalis [Yorkia?], Walcott [1906, pp. 569-570]........--...---.--------- Yorkia? orientalis.
ornatella [Iphidea], Grénwall [1902, p. 40].........-..---.---.----.------ Micromitra (Iphidella) ornatella.
Hall and Clarke [1892c, pp. 97-98]..--..--.--..------- Do.
Timmarssom [86> pps 25-26] 225-5 ee 425 soe ee see Do.
ornatella [Iphidea cnf.?], Hall and Clarke [1892c, Pl. IV, figs. 6 and 7]. ...Micromitra (Paterina) superba.
orta [Acrothyra signata], Matthew [1902b, pp. 385-386].........-.-...----- Acrothyra signata orta.
Matthew (1903; pp. 89--90]_--.-..-...---....---.. Do.
orthia [Syntrophia], Walcott [1905b, pp. 11-12]....--.....---....-------. Syntrophia orthia.
Onailantsy ora IMEln (Tin jozwAs)) [NEVIS 1), WM) ae ooadesocncoscoscodesacesoaessos Obolus.
Orthis barabuensis A. Winchell [1864, p. 228]. .......--...--.----.------ Syntrophia barabuensis.
Onxthisibayvaricayb arrancdeylS G82. 5199) eee eee ea aa Eoorthis bavarica.
IsphareyalGley |[IS{GS}0), 705 GLO] 2s bsscceascecececeusescaacosdes Do.
Orthis billingsi Hartt [1868, pp. 644-645]........2.....2-..-2.---2-------- Protorthis billingsi.
Tsemaiié (MOTE, (Oo: BURG). <5 soc2¢scs2esseceeresesoles a Do.
Hartt [89h pp 644645 aeons eee Do.
Matthew [8865.43] eo ae tee le er ee ee eats ieee et ea Do.
Wealkoorns | [ilstsHt, Toyas WS coc ecesesscocsasdseqscecossasaee Do.
Orthis christianize Brégger [1882, p. 48]..........-..-------------------- Eoorthis christianiz (in part) and E.
: daunus (in part).
Gagel [11890; pp. 10'and 34]_-- 222-222 222 22222222 ee. Eoorthis daunus.
Ixjeraube MEAS, OO. I gual Bl ccsecsssossaascesessnubcess Eoorthis christianie.
Pompeckyipl902 pai /|ee eet weer eee cee eres Eoorthis daunus.
Remrelé[ SS Ap t69] ose ak. ciee eee ean et open ae ae Do.
Remelé}[ls85 ssi easeee= eer eee ear ee eens Do.
Roemer [1885, pp. 36, 37, and 38]--......--....-.---- Do.
Orthis coloradoensis Meek [1870, p. 425]........-.-----.----------------- EKoorthis desmopleura.
Slarmmenemeel [EKO 19), B2Mes-cescescesscseasessaccscusce Billingsella coloradoensis.
Orthis desmopleura Meek [1872, p. 295].......----.--------------------- Eoorthis desmopleura.
Orthis? eurekensis Schuchert [1897, p. 286]........-----.-.-------------- Orusia? eurekensis.
Orthis eurekensis Walcott [1884b, pp. 22-23]..........-..---.------------ Do.

Orthis exporecta Linnarsson [1876, pp. 12-13].........-..---------------- Billingsella exporrecta.

SYNONYMIC REFERENCES. 79

Present reference.

Orthis exporrecta Kayser [1883, p. 35].--.-.-- ie so 4 ee ean wen se ate Billingsella exporrecta.
Wailers MEP by o> él esccsase sandavascccuucosuecesoas= Do.
Orthis hamburgensis Walcott [1884b, p. 73]-..-...---.------------------- Eoorthis desmopleura?.
Oraianiss lameliasnt Ieingstere SIE, Toe Gl eooc ou scacadusosaes took susuesasecusoces Billingsella hicksi.
Ibpiomarnmsstox | (TNSAG}, Joye), WEA. cose esac sud sscsososcussons Billingsella exporrecta rugosicostata.
OxthisihicksiyDavidsony [1868 yps3l4 | feeeeeeenes as -eeaeeee eee ease ese ee Billingsella hicksi.
IDRC ROM. [MEG Tope la occesesuconsneds oUnocoesooneeses Do.
Orthis? highlandensis Walcott [1886b, pp. 119-120]...........--.--.------ Billingsella highlandensis.
Weulloouit [stile jo, GUZM |. 2 s2sce ceacosceesussossessce Do.
Orthis kuthani Pompeckj [1896b, pp. 514-515]......-----...-----..------ Nisusia (Jamesella) kuthani.
Orthisilenticularis Brogrer [1882* pi 4s]is-2-s52e-5-2- 2-4 ns- eee eae Orusia lenticularis.
Deyokom (MN, (dBi. occ ccacbasscsasoecsoansesoeso Do.
Waradsone |S 69s ppe2e0=232) eee eee eee eee eee Do.
Menndaery [NEO2, joo, HOS) oo ocoosee soe skcobesseseeunes Do.
Matthewall 903s ppe 23-26] Pease eeeee eee eee eee Do.
Teoeumeye |[ls(5, Jl JUL stess, 4=0]| osdanccccacesssunScse cc Do.
INoeiaae | Mets), 100, wes sae ca cdadosseosdodse apes cece Do.
Seuliieyr |MEXO)), 10; BAM scsesece-cesccegscecaccasesessse Do.
Salter and Etheridge [188], pp. 544-545]..............- Do.
Orihislenticulariss? Kayser [S76 ps 9)lssssssses- +2 + esses eae eee ace ooo Do.
Orthis lenticularis atrypoides Matthew [1892, p. 48]........-....-.-.------ ‘Orusia lenticularis atrypoides.
Wenn [IGOR 10), Z| nassassceosesseseecc Do.
Orthis lenticularis lyncioides Matthew [1892, p. 49].-......-------------- Orusia lenticularis lyncioides.
Matthew, [19035 ps 216|hs2 22 s2sss-55- 22 eee Do.
Orthis lenticularis strophomenoides Matthew [1892, p. 49].--------------- Orusia lenticularis.
Matthew: (19035 py 2ii7a== snes sano Do.
Orthis lindstrémi Linnarsson [1876, pp. 10-12].....--.....-----.--------- Billingsella lindstrémi.
Oxthisilimnarssoni Kayser [18835 ps 34s e442 55-- 25-055. - scene essa Eoorthis linnarssoni.
Orthis newtonensis Weller [1903, pp. 113-114]. -....--...-----.--------- Eoorthis newtonensis.
Orthis (?) peculiaris Tate [1892, pp. 185-186]. ........---..-------------- Kutorgina peculiaris.
Orthis pepina Hall [1863, pp. 134-135] ...................--------------- Billingsella coloradoensis.
TS QR [USYB7/,, 10s LIB ||o o's cccsesesocadesscea- Fe ea ayet oe ees Say ane Do.
Wulmmitatellel ES Tom, WOSIVAY|S 5 6 og ob accassscaessa=se5e0s> Do.
Orthis perpasta Pompeckj [1896h, pp. 515-516] ........-...--------.---- Nisusia (Jamesella) perpasta.
Orthis perpasta macra Pompeckj [1896b, p. 516]........--..---.-------- Nisusia (Jamesella) perpasta macra.
Orthis perpasta subquadrata Pompeckj [1896b, p. 516]. ........--.--..--- Nisusia (Jamesella) perpasta subquadrata.
Orthis primordialis Mallada [1875, p. 31]. ......-...--.----.------------ Eoorthis primordialis.
de Verneuil and Barrande [1860, pp. 532-533]...-..--- Do.
Orthis quacoensis Matthew [1886, pp. 43-44]... ......--...-------------- Protorthis quacoensis.
Orthis? remnicha Walcott [1899, pp. 451-452, Pl. LXI, figs. 3 and 3a; Pl.
JED Mis cteray Glia Kee ol eee a SS HEOeMAnidde deeds EKoorthis remnicha. The text includes
both E. remnicha and E. iddingsi.
Orthis remnicha Walcott [1899, pp. 451-452, Pl. LXII, figs. la-b] -.-.-..-. Eoorthis iddingsi. The text includes both
E. iddingsi and E. remnicha.
N. H. Winchell [1886, pp. 317-318] ...-.-....-.---------- Eoorthis remnicha.
Orthis romingeri Barrande [1848, p. 203]. -....------..------------------ Billingsella romingeri.
Barrande [1879a, Pl. LXII, figs. mu: 1-4].-....---.-..---- Do.
Heistmam tele sor hee ee Le te ae, Sl NEAR pele eye ee re eee Nisusia (Jamesella) kuthani.
alias. neer rena cfr a aaa Sees 4 arated tale Aerage oleae aie Do.
TRIB TZ CLs ee etter Sus era shee avn, 0 an ca een Do.
DRG Cie eae tne ere Oe aed ek toa ela Dee Rae eRe Do.
Kaistaleene ace eee nece So es ine sme me Se ee ee ee Eee Do.
INOValke eee sa eeace orc Soe aot te eehnns Demet eae eee pee nee Do.
Pompecky [1896b, pp. 513-514). ...........2....-...--.- Billingsella romingeri.
Wertz Wee eet ores creas Roya cd hy ae ered eee Nisusia (Jamesella) kuthani.
Orthis salemensis Oehlert [1889, p. 1139]..........--..---..---.--------- Billingsella salemensis.
Welkeont (MESH, 0. IWOSUOI |S 3 s oon cbscodooseenacascoccs Do.
Walkeorie |iebiley, jojo. GUZ SGI) = oe cesccdncacsagsseccese Do.
Oxthisisaltensishitayseni[il'S7G. pe elles 220222225 22ers eases ane Eoorthis saltensis.
Kayseri [ilS97,p 280 eae. cree 2 Soc ene hee ees Do.
Orthis (?) sandbergi Walcott [1899, pp. 452-453]... ..-..-..--...-.-.---- Otusia sandbergi.

Orthis sandbergi N. H. Winchell [1886, p. 318]. ........--..--.---------- Do.

80 CAMBRIAN BRACHIOPODA.

Present reference.

Orthis\(?)/ tate Etheridge jr. (1905; ps 249]as esses ae ee eee eee Eoorthis tate.
Orthistmewlakonu Buch) (tsp pai-s) ces eeeaseee eee eee ee eee eee eee Obolus apollinis.
Orthis warthi Waagen [1891, pp. 102-104]. ..........-..-.....-........-. Wynnia warthi.
Orthis spaiKayseri[18 76; sp s9)| piste ea acacia ete eee a Orusia lenticularis.
Pompeck jj S96a' ios Alas st sa ees egerde nites ase eee Eoorthis bavarica.—
Pompeckj [1896b, p. 514, Pl. XV, fig. 6]......................- Eoorthis sp. undt. a.
IReaoeelie] |MENT), jo, DIL TAL, ihe. Wibesecsosonessosgcoseese Koorthis sp. undt. b.
Orthis (or Orthisina) sp. Etheridge [1905, p. 250]......-....-...-.--.---- Huenella etheridgei.
Orthis (Billingsella) pepina Sardeson [1896, p. 96]. - ..---------------Billingsella coloradoensis.
Orthis (Finkelnburgia) Walcott [1905a, pp. 277-278]. - 3 ..-----Finkelnburgia.
Orthis (Finkelnburgia) finkelnburei Walcott [1905a, pp. ). 278-279]. - STs oh a Finkelnburgia finkelnburegi.
Orthis (Finkelnburgia) osceola Walcott [1905a, p. 279].---...------------ Finkelnburgia osceola.
Orthis (Finkelnburgia) osceola corrugata Walcott [1905a, p. 280]. ...-...-- Finkelnburgia osceola corrugata.
Orthis? (Orthisina?) pepina Hall [1883, Pl. XX XVII, figs. 16-19]......-- Billingsella coloradoensis.
Orthisi(Oxpsia) MWallco tts [90 Sampo ype ies eee ae Orusia.
Orthis (Orusia?) eurekensis Walcott [1905a, p. 277].....-..-.-.----------- Orusia? eurekensis.
Orthis (Orusia) lenticularis Walcott [1905a, pp. 273-276]..............---- Orusia lenticularis.
Orthis (Orusia) lenticularis atrypoides Walcott [1905a, p. 276]..-..------- Orusia lenticularis atrypoides.
- Orthis (Orusia) lenticularis lyncioides Walcott [1905a, p. 277].....---.--- Orusia lenticularis lyncioides.
Orthis (Plectorthis) Walcott [1905a, pp. 257-259].................-.------ Koorthis.
Orthis (Plectorthis) agreste Walcott [1906, p. 570]......-...--.-.-.------- Koorthis agreste. s ;
Orthis (Plectorthis?) atava Walcott [1905a, pp. 259-260]...............-- EKoorthis atava.
Orthis (Plectorthis) christianiee Moberg and Segerberg [1906, p. 69]------ EKoorthis christianiz (in part only). The
: reference includes also E. daunus and
E. tullbergi.
Walcott [1905a, pp. 260-261]. -..-.-..-.- Koorthis christianie.
Orthis (Plectorthis) daunus Moberg and Segerberg [1906, p. 69]....------- Koorthis daunus.
Walleots MOE, jo. Balls os ss ces: esodesecace Do.
Orthis (Plectorthis) desmopleura Walcott [1905a, p. 261].........-.------ EKoorthis desmopleura.
Orthis (Plectorthis) desmopleura nympha Walcott ee p. 26 ih Wenner Koorthis desmopleura nympha.
Orthis (Plectorthis) diablo Walcott [1905a, p. 262]. - .-.-------------Hoorthis? diablo.
Orthis (Plectorthis) doris Walcott [1905a, pp. 262— 263]. Bolas Sen OR aoa oe oee Koorthis doris.
Orthis (Plectorthis) hastingsensis Walcott [1905a, p. 263]. ....-...--- ..---Hoorthis hastingsensis.
Orthis (Plectorthis) iddingsi Walcott [1905a, p. 264].............-..----- Eoorthis iddingsi.
Orthis (Plectorthis) indianola Walcott [1905a, pp. 264-265]...........----- Hoorthis indianola.
Orthis (Plectorthis) johannensis Walcott [1905a, pp. 265-266]........-.-- Eoorthis johannensis.
Orthis (Plectorthis) kayseri Walcott [1905a, p. 266]. ....-..--.----------- Koorthis kayseri.
Orthis (Plectorthis) kichouensis Walcott [1906, p. 570]...-.-..-.-------- HKoorthis kichouensis.
Orthis (Plectorthis) linnarssoni Walcott [1905a, p. 266]... .----.--.------Eoorthis linnarssoni.
Orthis (Plectorthis) newtonensis Walcott [1905a, p. 267]........---.----- EKoorthis newtonensis.
Orthis (Plectorthis) pagoda Walcott [1905a, pp. 267-268]. -.-.....-.---.--- Eoorthis pagoda.
Orthis (Plectorthis) papias Walcott [1905a, p. 268]. .-..--.-..--.--------- Koorthis papias.
Orthis (Plectorthis) remnicha Walcott [1905a, pp. 268-269] ...-...-------- Eoorthis remnicha.
Orthis (Plectorthis) remnicha suleata Walcott [1905a, p. 269]..--..-..----- Eoorthis remnicha sulcata.
Orthis (Plectorthis) remnicha texana Walcott [1905a, p. 270]....-.-------- EKoorthis remnicha texana.
Orthis (Plectorthis) remnicha winfieldensis Walcott [1905a, p. 270] eichege apse Eoorthis remnicha winfieldensis.
Orthis (Plectorthis) retroflexa Walcott [1905a, pp. 270-271].-..--..-------- Billingsella retroflexa.
Orthis (Plectorthis) saltensis Walcott [1905a, p. 271]. - Safe ....----Hoorthis saltensis.
Orthis (Plectorthis) tullbergi Moberg and Segerbere [1906, p- 69]. segsesesc Eoorthis tullbergi.
> \Weikeoiit [MCE 795 AM ,sesescceeccecaccasess Do.
Orthis (Plectorthis) wichitaensis Walcott [1905a, pp. 271-272]..-..----.---- EKoorthis wichitaensis.
Orthis (Plectorthis) wichitaensis leviusculus Walcott [1905a, p. 272] . . ..-Eoorthis wichitaensis leviusculus.
Orthis (Plectorthis) wimani Moberg and Segerberg [1906, p. 70]....-----.--Hoorthis wimani.
Welleort |MO0sD, 1), Bile ssoccussessoccoscsene Do.
Orthis (Plectorthis) sp. Walcott [1905a, pp. 272-273]......-..------------ EKoorthis sp. undt. a and b.
Orthis (Plectorthis) sp. undt. Walcott [1906, p. 571]---.------------------- Eoorthis various sp. undt.
Orthis (Protorthis) billingsi Wysogérski [1900, p. 227]........--..--.------ Protorthis billingsi.
Orthisina alberta Matthew [1902c, p. 109] ....-...-..:-..--+.------------ Nisusia alberta.
Walcott fIS89cxn yar a Esse ieee tke os UE eee eee Do.
Orthisina? billingsi Matthew [1891, p. 131]..........-...--.--.----------- Protorthis billingsi.

Oniarsthae, Gonna, Wayne [WEG jo. WE | 2s ccsodoncosececcousbeusescaasandes Nisusia compta.

ee

oe

SYNONYMIC REFERENCES. 81

Present reference.

Orthisina festinata Billings [1861b, p. 10].--..-.....-..-..--.------------- Nisusia festinata.
Billings [186lc, p. 949]-...----.-....-..- Sco eee ees Do.
Islas [MISA 10s WOD||assssgssenssosccossescecaacenccc Do.
Bilbo! UNAS, Tos ZAI |-ccooasccossdsssceconecooussoens Do.
Billings 863% ps 284 shook 2892—c] eeee eee eee eee eee Do.
Wall@orit [II9, joo WAOSNP I co onscedescasssocsansecs0% Do.
Wwelkooi, Meike, fo, GUB)|sscotactossoacecosenscusoncases Do.
Orthisina (?) johannensis Matthew [1892, pp. 49-50] -....-...--.-.-------- Eoorthis johannensis.
Oxthisinaorientalis)| Walcott (1S86b> p. W20]E4--224c2+-4-- 422-2222 see Billingsella orientalis.
Walcot [leila jos GIB: osccsccesecducsacsauesessses Do.
Winntfel ali [S845 py 144] bees seesaw eee ease ces ee Do.
Orthisina pellico de Verneuil and Barrande [1860, pp. 535-536]. ...-...--- Nisusia (Jamesella) pellico.
(Orthisina?) pepina [Orthis?], Hall [1883, P]. XX XVII, figs. 16-19]......- Billingsella coloradoensis.
Orthisina quacoensis Matthew [1891, p. 131].......,...........-...-.... Protorthis quacoensis.
Orthisina? transversa.Walcott [1886b, p. 121]......-.....--...------------- Nisusia festinata transversa.
Wrealleortts |MeIEY, jo), Oil) co accosesecooecacacdocscacccs Do.
OnihisimanvaticmayMalladay [eiios poz |ssssscsse sees eee see eeeeeaee sere eee Nisusia? vaticina.
de Verneuil and Barrande [1860, pp. 533-535] ..-.-...-- Do.
Orthisina [Orthis or] sp. Etheridge [1905, p. 250]..........-..---...------- Huenella etheridgei.
orus [Obolus (Lingulella)], Walcott [1905a, p. 330]..........-........-..---Lingulella ora.
Orusia Walcott [1908e, Pl. XI, and pp. 142 and 148]....-...........-.--.- Orusia.
(Onisra)) | [Oxthis| Walcott [90sah py 2(3|pesssescse eae eae eee see eee eee eee Do.
(Orusia?) eurekensis [Orthis], Walcott [1905a, p. 277].-.......---.-------- Orusia? eurekensis.
(Orusia) lenticularis [Orthis], Walcott [1905a, pp. 273-276]......-....--.-- Orusia lenticularis.
(Orusia) lenticularis atrypoides [Orthis], Walcott [1905a, p. 276]. ....--.-- Orusia lenticularis atrypoides.
(Orusia) lenticularis lyncioides [Orthis], Walcott [1905a, p. 277]....----.-- Orusia lenticularis lyncioides.
osceola [Obolus (Lingulella) mosia], Walcott [1898b, p. 409]..-..-..--.--.-- Lingulella mosia osceola.
osceola [Orthis (Finkelnburgia)], Walcott [1905a, p. 279]. ..-.-......--.-.-- Finkelnburgia osceola.
osceola corrugata [Orthis (Finkelnburgia)], Walcott [1905a, p. 280].......-- Finkelnburgia osceola corrugata.
Otusia Walcott [1908e, Pl. XI, and pp. 142 and 148]..-........-..----..-:. Otusia. F
(Otusia) [Billingsella], Walcott [1905a, p. 246]..................-.....-.- Do.
(Otusia) sandbergi [Billingsella], Walcott [1905a, pp. 246—-247]...........-- Otusia sandbergi.
Ofusiaputahensis Walcott [mewlpenss--eeeessesesee eee eee eee eee ec eee Otusia utahensis.
ovalis [Acrotreta], Walcott [1902, p. 592].- Si! eee eee eeee AGLoureranovalise
ovalis [Lingulella ferruginea], Davidson [186s, p. 307] - BO ROE SRS aa ance sae Lingulella ferruginea.
Hicks [Salter and Hicks, 1867, p. 341]-..-.-- Do.
ovalis [Lingulella? inflata], Matthew [1895a, p. 127].-...-.-...-..--.---.-- Acrotreta inflata.
ovaitay |e ma) Bimam ons) [fl S42 peel Oo) seeeeeeene sees eee eee ee eee Lingulella prima.
McCoy [M846 spe 24] Be ee ee ee os enc) 2s eee ee eee eee Lingula ovata, not Lingulella davisi.
McCoy, [M8540 pm 254) cae cee sence cance scene esse ae eer Lingulella davisi (in part) and Lingula
: ovata (in part),
oweni [Obolus (Lingulella)], Walcott [1898b, p. 410].............--.------ Lingulella oweni.
ovata [Ungula], Pander [1830, p. 59, Pl. XXVIII, figs. 6a—b]............. Obolus (Schmidtia) celatus.
Pander [1830, pp. 59 and 154, Pl. III, fig. 23] ...........- Obolus apollinis.
P.
pacifica [Acrotreta], Walcott [1905a, p. 301]...-....-..-.-..----.---------- Acrotreta pacifica.
pagoda [Orthis (Plectorthis)], Walcott [1905a, pp. 267-268]...........-..-.- Eoorthis pagoda.
Palzeobolus Matthew [1899b, pp. 201—202]...............-..-..------------- Obolus (Paleeobolus).
Matthewall903e ppesl40c14il|e. yo.2 4) VG ae) eaeeaie Do.
(Paleeobolus) [Obolus], Walcott [1908e, Pl. XI, and pp. 142 and 144]...... Do.
Palzeobolus bretonensis Matthew [1899b, p. 202].....-.--......------------ Obolus (Palzeobolus) bretonensis.
Matthew [1903, pp. 141-143] ...........-.--.------ Do.
(Paleeobolus) lens {Obolus], Matthew [1903, pp. 144-146]....-..-..--.--.-- Obolus (Palzeobolus) bretonensis lens.
(Palzobolus) lens longus [Obolus], Matthew [1903, pp. 146-147]. .......-- Do.
palliatus [Obolus?], Barrande [1868a, pp. 104-105, fig. 64]........-..--..-- Obolus? bavaricus.
Barrande [1868a, pp. 104-105, fig. 65]..-........-...-. Obolus? palliatus.
Barrande [1868b, p. 693, fig. 64]........-.-..-.--.---- Obolus? bavaricus.
Barrande [1868b, p. 693, fig. 65]..-......-- Te ALES Obolus? palliatus.
pandemia [Obolus], Walcott [1898b, p. 388].....---.----.--.-------------- Obolus pandemia.
pandexaAcrothele|ssWallcott: [ew ppesseeeee eee eee eee eee ee ee Acrothele panderi.
62667°

82 CAMBRIAN BRACHIOPODA.

Present reference.

panderi [Keyserlingia], Karpinsky [1887, .p. 476] ........------------------ Helmersenia ladogensis.
panderi [Obolus], Mickwitz [1896, pp. 149-151]. -.............--..------- Obolus pander.
pannula [Iphidea], Matthew [1902c, p. 110].............-...-.-.---.------Micromitra (Iphidella) pannula.
pannula [Iphidella], Walcott [1905a, p. 307]..----..----------------------- Do.
pannula [Kutorgina], Pack [1906, p. 296].............--------.--..-.-.-- Do.
Weleons |(MEEISI9), 1 WO cscemsscoussseeeacsocscescose Do.
\Welkeors SB, TO. IDO, caccasscosceasacseacscessoscc- Do.
Walcott [1891a, p. 609]. - wed Do.
pannula [Micromitra (Iphidella)], Walcott [1908c, } p. . 244, Pl. i fas, i Reece Do.
pannula maladensis [Iphidella], Walcott [1905a, p. 306]. -.-----------------Micromitra (Iphidella) pannula maladensis.
pannula ophirensis [Iphidella], Walcott [1905a, p. 306].....-.-...-.-------- Micromitra (Iphidella) pannula ophirensis.
pannulus [Iphidea], Grabau and Shimer [1907, p. 201]..-...-.- LAS eee Micromitra (Iphidella) pannula.
Stelomereloverts ([MUSI7/, To PRs oncaccsacacessoooeeacsssess Do.
pannulus [Trematis], White [1874, p. 6].....-..--..-----.----------------- Do.
Wyte (US/7/, Tod: BSB |sescososescesssosqoessoessans Do.
papellata-prima [Acrotreta], Matthew [1902a, pp. 391-392]..........--..-- Acrothyra sera.
papias [Orthis (Plectorthis)], Walcott [1905a, p. 268]..-....-...----.------- Eoorthis papias.
papillata [Acrotreta], Matthew [1902b, pp. 390-391]....................-.-.Acrothyra sera.
Matthew, [19035 p. 95]---.---.-2--- 2222-2222 - ose eee Do.
papillata lata [Acrotreta], Matthew [1903, pp. 95-96]....-...--..---------- Do.
papillata-prima [Acrotreta], Matthew [1903, pp. 73-74]. ....-.-.--------- Do.
papillata var. [Acrotreta], Matthew [1902b, p. 391]....--...-..--..---.--- Do.
parvula [Acrotreta], Walcott [1902, p. 592]......--..-..--.-.-.---------- Acrotreta parvula.
parvula [Obolella], Wallerius [1895, pp. 65-66]............-..------------ Do.
parvus [Dicellomus], Walcott [1905a, pp. 315-316]. ..................-.-Dicellomus parvus.
parvus [Obolus], Walcott [1908d, pp. 61-62]. ............-...-...-..---- Obolus parvus.
Paterma Beecher [il89ls pric45] eee erent nae e eee eee eee eee ae Micromitra (Paterina).
Hallfandi Clarkes [l$92annps 247) yee eee ee eee eee Do.
HallVandi@larke} [i892 5515 0s] Heeneee eee eee ee eee ee eeeee Do.
Walcott} [89 7byep 10S] hecho cmesee aan esc ass Aen sees eee Do.
(Paterina) [Micromitra], Walcott [1908e, Pl. XI, and pp. 142 and 143]......Micromitra (Paterina).
Paterina labradorica Beecher [1891, pp. 345-346]. ...........-..-.-.----- Micromitra (Paterina) labradorica swanton-
ensis.
Hall and Clarke [1892a, p. 247]....-.--.----------- Do.
(Paterina) labradorica var. undt. [Micromitra], Walcott [new] - - - --------Micromitra (Paterina) labradorica var-undt.
(Paterina) stissingensis ora [Micromitra], Walcott [new]. -....------------- Micromitra (Paterina) stissingensis ora.
(Paterina) stuarti [Micromitra], Walcott [1908d, p. 58]... ..--- eet sate Micromitra (Paterina) stuarti.
(Paterina) wapta [Micromitra], Walcott [1908d, p. 59]......-..----.---.-Micromitra (Paterina) wapta.
(Paterina) williardi [Micromitra], Walcott [1908d, p. 60]....-..-.--------- Micromitra (Paterina) williardi.
Paterina (Micromitra) Schuchert [1905, p. 329]......-..-..-------------- Micromitra.
pealei [Iphidea], Walcott [1897b, pp. 712-713]... ....-..-.--.----------- Micromitra pealei.
pectenoides [Dicellomus], Walcott [1901, p. 673]............-------------- Dicellomus pectenoides.
Walcott [1905a, p. 316].--.---...-.------------ Do.
pectenoides [Obolella], Schuchert [1897, p. 275].......-..-.-.----------- Do.
pectenoides [Obolus], Whitfield [1875, p. 103].............-.-.--------- Do.
pectenoides [Obolus?], Whitfield [1880, pp. 338-339]... ..-.-..-.-.------ Do.
peculiaris [Orthis (?)], Tate [1892, pp. 185-186]..................-------- Kutorgina peculiaris.
pelias [Obolus (Lingulella)], Walcott [1905a, pp. 330-331].-.....-......-- Obolus meconnelli pelias.
pellico [Orthisina], de Verneuil and Barrande [1860, pp. 535-536] ........- Nisusia (Jamesella) pellico.
pepina [Billingsella], Hall and Clarke [1892a, Pl. VIII, figs. land 2]..... Billingsella coloradoensis.
Hall and Clarke [1892c, p. 230] ....--.-.------.---- Do.
pepina [Orthis], Hall [1863, pp. 184-135] -.-.............---------------- Do.
Lalli [8676t peels Ses Sassen k Aaa te eee eer ate Do.
\Widomnsaveltol [UI jojo. WORM AU]. = > se 2 ecssss5es02ee2$s0e5¢ Do.
pepina [Orthis (Billingsella)], Sardeson [1896, p. 96] - - 7s Do.
pepina [Orthis? (Orthisina?)], Hall [1883, Pl. XXXVIL, fia 16-19]. eo ease Do.
perattenuatus [Lingulepis], Whitfield [1877, p. 9]........---------------- Lingulella perattenuata.
Whitfield! [ii880> pa sei)|22s22--24-5552 esse == Do.
perattenuatus [Obolus (Lingulella)], Walcott [1899, p. 443]. -.-.....------ Do.
perfectus [Obolus (Fordinia)], Walcott [1908d, pp. 65-66]. . - .-.---------- Obolus (Fordinia) perfectus.
perpasta [Nisusia (Jamesella)], Walcott [1905a, pp. 254-255].........-- '_...Nisusia (Jamesella) perpasta.
perpasta [Orthis], Pompeckj [1896b, pp. 515-516].........-.--.--------- Do.
perpasta macra [Nisusia (Jamesella)], Walcott [1905a, p. 255]-....-..------ Nisusia (Jamesella) perpasta macra.

perpasta macra [Orthis], Pompeckj [1896b, p. 516].........------------- Do.

SYNONYMIC REFERENCES. 83

perpasta subquadrata [Nisusia (Jamesella)], Walcott [1905a, p. 255]... ..-
perpasta subquadrata [Orthis], Pompeckj [1896b, p. 516]. --.-..---
perugata [Kutorgina], Walcott [1905a, p. 310]...............------
petalon [Lingula], Bornemann [1891, p. 438]..........-..-.-------
Danaicleorn [RIE O, BOS]| socseose sssose5ecsacsse

Darko {[IS7il, fo. BB) ccoscsaac cocscossccsces

phaon [Obolus (Lingulella)], Walcott [1898b, pp. 410-411]... .-.....:.--
pheres [Obolus], Walcott [1905a, p. 328]..................--------
Philhedra von Huene [1899a, pp. 146-147]. .......---.-.--------
von Huene [1899b, pp. 216-218 and 297-298]......-...--

Koken [1889, pp. 465 and 467]... ...........----------

Walcott [1908e, Pl. XI, and pp. 142 and 147]..........-
Philhedra? columbiana von Huene [1899b, pp. 216 and 298]....-.....--
Philhedra columbiana Walcott [1908c, Pl. I, figs. 5 and 5a]...-.-.-.-------
phillipsi [Kutorgina cingulata], Matley [1902, pp. 145-147]. ------------
phillipsi [Obolella?], Davidson [1866, pp. 62-63]... .....-..--.---
phillipsi [Obolella], Holl [1865, p. 102].....................--.---
Teinilitjns MBA, Ds Gilbecesccsccsdocscesecccese

phillipsi [Obolellus?], Roemer [1876, Pl. XI, figs. 6a-d].....-...--
phillipsia [Obolella], Dall [1877, p. 41]......-....-.....-..------
pileolus [Discina], Davidson [1868, pp. 312-313]. ..........---.---
Danmaleom |[MSW/il, jo. BH. 3 ceecscsscesoccoeanese

(Hicks MS.) Salter [1866a, p. 285] -.......--.--

pileolus? [Discina], Hicks [1871, Pl. XV, figs. 12 and 12a]......----.--.-
pileolus [Orbiculoidea], Hall and Clarke [1892c, p. 137]... -.-..----------
pinnaformis [Lingula], Owen [1852, p. 583] .-.----.-.-.----------
pinnaformis [Lingulevis], Hall [1863, pp. 129-130, Pl. VI, figs. 12 and 13].

Present reference.

_Nisusia (Jamesella) perpasta subquadrata.

Do.

Kutorgina perugata.

Obolus? meneghinii.

Does not equal Obolus? meneghinii.
Do.

- Lingulella phaon.

Obolus pheres.
Philhedra.

Do.

Do.

Do.

.Philhedra columbiana.

Do.

-Micromitra (Paterina) sine

Do.
Do.
Do.
Do.
Do.
Orbiculoidea pileolus.
Do.
Do.

-Stenotheca pileolus, a gastropod.
- Orbiculoidea pileolus.

Lingulella (Lingulepis) acuminata.
Obolus matinalis.

Hall [1863, pp. 129-130, Pl. V1, figs. 14-16]. ....Lingulella (Lingulepis) acuminata.

Hall [1867, p. 107, Pl. I, figs. 12 and 13]
Hall [1867, p. 107, Pl. I, figs. 14-16]. .......--
Whitfield [1880, p. 335]..-....-..--...-
Whitfield [1882, pp. 169-170]...........

pinnzformis [Lingula], Hall [1862, p. 435, and fig. 3, p. 21]

pinniformis [Lingulepis], Dwight [1886, p. 208]......:-.-.--------
Grabau and Shimer [1907, p. 193]... -.-.-
Hall and Clarke [1892a, p. 232]....-..---
Hall and Clarke [1892b, p. 548]....------
‘Hall and Clarke [1892c, p. 60]...-..--.--

Meek and Hayden [1865, pp. 2-3]

Selanne (MEE, 1d, Aso cescessecc=scs
plana [Ungula], Pander [1830, pp. 59 and 163]. --.--.-.-----------
plana or convexa [Ungula], Pander [1830, p. 163]... -.-.----------
plana retroflexa [Clitambonites (Gonambonites)], Matthew [1895b, p. 267].
planus retroflexus [Clitambonites], Schuchert [1897, p. 184].....---
Platyceras etheridgei Tate [1892, p. 184]. ..............-.--------
Plectorthis Grabau and Shimer [1907, pp. 250 and 251]..........--

Hall and Clarke [1892c, pp. 194-195]... .--.--.-.-.---
(Plectorthis) [Orthis], Walcott [1905a, pp. 257-259] ..........-----
(Plectorthis) agreste [Orthis], Walcott [1906, p. 570].....-..-------

(Plectorthis?) atava [Orthis], Walcott [1905a, pp. 259-260] - -

(Plectorthis) christianize [Orthis], Moberg and: Segerberg [1906, p- ». 69].

Walcott [1905a, pp. 260-261]. -

(Plectorthis) daunus [Orthis], Moberg and Segerberg [1906, p. 69]...

Walcott [1905a; p: 261] b2222 2222-2 ==
(Plectorthis) desmopleura [Orthis], Walcott [1905a, p. 261]. ...-.--
(Plectorthis) desmopleura nympha [Orthis], Walcott [1905a, p. 262]..-----
(Plectorthis) diablo [Orthis], Walcott [1905a, p. 262].......--------
(Plectorthis) doris [Orthis], Walcott [1905a, pp. 262-263]. ...--.---
(Plectorthis) hastingsensis [Orthis], Walcott [1905a, p. 263]. .....--
(Plectorthis) iddingsi [Orthis], Walcott [1905a, p. 264]...-.......-

Obolus matinalis.

-Lingulella (Lingulepis) acuminata.

Do.
Do.
Do.
Do.
Do.
Do.
Do.
Do.
Do.
Do.
Obolus apollinis.
Do.

- Billingsella retroflexa.

Do.
Micromitra (Paterina) etheridgei.
Eoorthis (in part) and Plectorthis (in part),
Plectorthis, not Eoorthis.
Eoorthis.
EKoorthis agreste.

..Hoorthis atava.

Eoorthis christianize (in part only). The
reference includes also E. daunus and
E. tulibergi.

..-Eoorthis christianie.

Eoorthis daunus.
Do.
Eoorthis desmopleura.

-Eoorthis desmopleura nympha.

Eoorthis? diablo.

Aaoeae Eoorthis doris.
See es Hoorthis hastingsensis.

Koorthis iddingsi.

84 CAMBRIAN BRACHIOPODA.

Present reference.

Plectorthis indianola Grabau and Shimer [1907, pp. 251-252]..-.......... Hoorthis indianola.
(Plectorthis) indianola [Orthis], Walcott [1905a, pp. 264-265]. ....-----.-- Do.
(Plectorthis) johannensis [Orthis], Walcott [1905a, pp. 265-266].......-.... Eoorthis johannensis.
(Plectorthis) kayseri [Orthis], Walcott [1905a, p. 266]. ...-...--..--.---.- Eoorthis kayseri.
(Plectorthis) kichouensis [Orthis], Walcott [1906, p. 570].-......-..-.-..-- Eoorthis kichouensis.
(Plectorthis) linnarssoni [Orthis], Walcott [1905a, p. 266]----....-..-.-.--- Eoorthis linnarssoni.
(Plectorthis) newtonensis [Orthis], Walcott [1905a, p. 267]... . ...--..---..Eoorthis newtonensis.
(Plectorthis) pagoda [Orthis], Walcott [1905a, pp. 267-268]. - .-..--.-.--.- Eoorthis pagoda.
(Plectorthis) papias [Orthis], Walcott [1905a, p. 268]. .....--..--.--.----- Hoorthis papias.
Plectorthis remnicha Grabau and Shimer [1907, p. 252]. --..-....-.------ Eoorthis remnicha.
(Plectorthis) remnicha [Orthis], Walcott [1905a, pp. 268-269]...-..---...-- Do.
(Plectorthis) remnicha sulcata [Orthis], Walcott [1905a, p. 269].-.........- Eoorthis remnicha sulcata.
(Plectorthis) remnicha texana [Orthis], Walcott [1905a, p. 270]--.--...-.-- Eoorthis remnicha texana.
(Plectorthis) remnicha winfieldensis [Orthis], Walcott [1905a, p. 270]. .--.-- Eoorthis remnicha winfieldensis.
(Plectorthis) retroflexa [Orthis], Walcott [1905a, pp. 270-271]...-....--...- Billingsella retroflexa.
(Plectorthis) saltensis [Orthis], Walcott [1905a, p. 271]. ......-.--.--.--.-- Eoorthis saltensis.
(Plectorthis) tullbergi [Orthis], Moberg and Segerberg [1906, p. 69]--.----- EKoorthis tullbergi.
Wraleotta [90 5am a2 (ll | see ae Do.

(Plectorthis) wichitaensis [Orthis], Walcott [1905a, pp. 271-272].....-...-- Eoorthis wichitaensis.
(Plectorthis) wichitaensis leviusculus [Orthis], Walcott [1905a, p. 272]... .Hoorthis wiehitaensis leviusculus.
(Plectorthis) wimani [Orthis], Moberg and Segerberg [1906, p. 70]-...------ EKoorthis wimani.

Wailcotth|l 9052s pa 72) eeeeesa epee eee Do.
(Plectorthis) sp. [Orthis], Walcott [1905a, pp. 272-273]. -.--..-..--------- Eoorthis sp. undt. a and b.
(Plectorthis) sp. undt. [Orthis], Walcott [1906, p. 571]. --.---..-....-..-- Eoorthis various sp. undt.
plicatella [Billingsella], Walcott [1905a, pp: 240-241]...........-...-.-.-- Billingsella plicatella.
pogonipensis [Obolus (Lingulella)], Walcott [1898b, pp. 411-412].......... Lingulella pogonipensis.
polita [Aulonotreta], Kutorga [1848, pp. 279-282].............-.--..-.--- Obolus apollinis (in part), O. apollinis

ingricus (in part), and O. (Mickwitzella)
siluricus (in part).

joo bey [MD rreeitoxranrs|, JINN (NSW), 1D, AHO. oo osc cee e] seneoneosseeansoce Dicellomus politus.
Doli, |Torrovealla|,, JeleNl PUGH, jo, 245) .-.- cose cseccsessbeobeosesesescozsns Do.
polita [Lingula?], Hall [1862, pp. 21 and 435]. ....-....----- DIES ary 5 2s Do.
Molitay [Mere ula) vibttre loll | G25 io eels Gil erent ree Do.
polita [Obolella], Billings [1862e, p. 421] -...-..-...-.--..-----+---------- Do.
polita [Obolella?], Hall [1863, pp. 133-134] .........------.-------------- Do.
TELM [A SGrpep peel ehh eaue itecg yaa mnne ter rer Do.
polita [Obolella], Hall and Clarke [1892c, pp. 72 and 73]....-...----.---- Do.
Walcott [1886b, p. 111].--....---- SE re ee Benen Ae Do.
Wwilaaiivaellel [SO, joo. SOO] ose a2 2s sec ob oscesecaaanase Do. :
politus [Dicellomus], Grabau and Shimer [1907, pp. 189-190]. ....-.-...-- Do.
Walcott [1899, pp. 448 and 446]. ...........-..-..-- Do.
Walcott [1905a, pp. 313 and 316-318]. ......--....-- Do.
Polytcechia? montanensis Walcott [1905a, pp. 295-296] .........-..- saseee Clarkella? montanensis.
preecisus [Obolus (Schmidtia) celatus], Mickwitz [1896, pp. 166-167] ...-.- Obolus (Schmidtia) celatus.
pretiosa [Acrothele], Walcott [1898b, p. 402]...-..-..-....--.--.--------- Acrothele pretiosa.
pretiosa [Billingsia], Ford [1886a, p. 467]... -.----.-.------------------- Do.
pretiosa [Elkania], Ford [1886b, p. 325]. ........-.--.--.--.-------.--.-- Do. :
pretiosa [Linnarssonia], Grabau and Shimer [1907, p. 200]-.-.-.-.-------- Either Acrotreta sagittalis or Acrothele
pretiosa. (See p. 652.)
Hall and Clarke [1892c, p. 70]---.--.------------- Acrotreta sagittalis.
Sehmcherth [S97 p 9262 pee eee eae Acrotreta sagittalis (in part) and Acro-
thele prétiosa (in part).
Walloon; (WOOL, foe GiBlecssccccceeses5segecseoes , -Acrothele pretiosa.
pretiosa [Linnarssonia cf.], Hall [1890, p. 55]..-...-.....-.-.------------- Acrotreta sagittalis.
pretiosa [Mickwitzia], Walcott [1908d, pp. 54-55]. .-.-....--------------- Mickwitzia pretiosa.
pretiosa [Obolella], Billings [1862d, pp. 68-69]....-.----.---------------- Acrothele pretiosa.
Billa sh [lSG3sspse230) [ees eee Do.
Chapman [1863, p. 191]. ------ BL Mahood I a oa Do.
Choejormaann ([MGHE To, Mss osckeasseoessenorsdeesessods Do.
pretiosa [Obolella?], Walcott [1886b, p. 11i]..---.-.------.-.------------ Do.
pretiosa [Obolella (Linnarssonia)|, Dawson [1890, pp. 53-54] .-...-..-.---- Acrotreta sagittalis.
prima [Acrothele matthewi], Hall and Clarke [1892a, Pl. III, fig. 27]...--- Acrothele prima.

Hall and Clarke [1892c, Pl. III, fig. 25] ..-.-- Do.

SYNONYMIC REFERENCES. 85

Present reference.

prima [Acrothele matthewi], Matthew [1886, p. 41]..-......-....--.------ Acrothele prima.
Matthew [1895a, Pl. V, figs. 7a—b]- .--.------ Do.
Matthew [1902b, pp. 397 and 402]. .......-.. Do.
Matthew [1903, p. 104]. .-....-..-.----:.--.- Do.
prima [Acrothyra proavia], Matthew [1901b, p. 303].......--------------- Acrothyra proavia.
WikennlaeKy [MYO jo, B|s-22sc2scaccosecesesac Do.
Matthew [1903, pp. 58, 86, and 93].........--. Do.
prima [Acrothyra signata], Matthew [1902b, pp. 382-383]. ..-...-..---.--- Acrothyra signata prima.
Mientia@yy [GOR 1. 78] < cccesessascsceseeeseses Do.
prima [Acrotreta papillata], Matthew [1902b, pp. 391-392].......--.-.-.-- Acrothyra sera.
prima [Acrotreta papillata], Matthew [1903, pp. 73-74].....-...--.-.------ Do.
forma) [Ilias], Jevil liars ME, JO. GMS eee eee assscosses5Ga5 s0scc0ns64505 Lingulella (Lingulepis) acuminata.
IDimaven@ ins (MSE), 1D. ADs os coccesosssscbsoscsoeseaucsaes Lingulella prima.
aN [LSA sp Sil cease tals eee eee ee ean ee eee Do. ?
EAU Y[MS He os 204 ae eke 22 ee AO eo see ye ee ee Lingulella (Lingulepis) acuminata.
Jslenyclern MIO, 105 (Ell paacseaseores s5boceoeuacesecosens= Probably equals Lingulella (Lingulepis)
; acuminata.
Over, WEE oe (Ue einer ero aee se Anes aan ewes Lingulella (Lingulepis) acuminata.
IRo eres MEGS 0, UO eecdunecaacacataeseoenaeseonas de Obolus (Westonia) rogersi.
prima [Lingulella?], Hall and Ciarke [1892c, p. 69]..........-----.----.-- Lingulella prima.
prima [Lingulepis], Grabau and Shimer [1907, p. 193].........--.--.------ Lingulella (Lingulepis) acuminata.
Wigelk giavel Istenyelein |[MEGH), jos Bleosccsecescoscsocasossor Dicellomus politus.
Millera Siig plo ote acne hoses seremsee ae eereees Lingulella prima.
Sehrieh erty [VS 97- p12 60)| pes Lingulella prima (in part).
prima [Meekina], Walcott [1905a, p. 313]... ..........-..-..-+---.--:--- Linnarssonella tennesseensis.
prima [Obolella], Whitfield [1884, pp. 142-143]. ...........--.-..-...---- Lingulella prima.
prima [Orbicula], Owen [1852, p. 583]......... Wher Nistautt ie Sac ieee ec tans Lingulella (Lingulepis) acuminata.
ure |[MSBE, 10. BEB) Ec odsenndsccsenesccusesoncsanocascns Obolus matinalis.
primazea [Acrotreta], Walcott [1902, p. 593] ..........+.......---...-..-- Acrotreta primeva.
primzeva [Acrothele], Pompeckj [1896b, p. 603] ...............-.-..--.-- Acrothele primeeva.
primeva [Discina (Orbicula)], de Verneuil and Barrande [1860, p. 532] ---- Do.
primeeva [Lingulella], Davidson [1883, p. 208] ..........-.-.-.------------ Lingulella? primeva.
lebioles DISWAl toes Oe oes soeabooadaddsccesnosccsas Do.
Jeb@les [NISL Tes CEM oeasoosassensdadoccodoouucse. Do.
Salter and Etheridge [1881, p. 538]. .....-...---.-- Do.
primordialis [Orthis], Mallada [1875, p. 31]. ...........-.-......--.--:--. Koorthis primordialis.
de Verneuil and Barrande [1860, pp. 532-533]-..---- Do.
primordialis [Syntrophia], Hall and Clarke [1893b, p. 218]............-..- Syntrophia primordialis.
Waleout [GOSH Os ZIA|].o-ctocccoenocoscsoasces Do.
primordialis [Triplecia?], Halland Clarke [1892c, p. 270].......---.-..-.- Do.
primordialis [Triplesia], Whitfield [1878, p. 51]...-.........-.....-.--...- Do.
VWininavellel [MSO (0s WA pocccosecsconcootosscccues Do.
primordialis argia [Syntrophia], Walcott [1905a, p. 293]... ....-..-.-.---.Syntrophia primordialis argia.
primus [Obolus lens], Matthew [1902c, pp. 94-95]............-.--.------- Obolus (Palzeobolus) bretonensis lens.
primus [Obolus (Lingulepis)], Walcott [1901, p. 673]..........-..--..----- Lingulella prima.
prindlei [Obolus (Lingulella)], Walcott [1898b, p. 412]. ......-..-..-.---- Obolus prindlei.
priscus [Schizambon], Matthew [190la, pp. 277-278]. .........-.-...-..-- Schizambon priscus. :
Marthe wa [1903s pa Si-l'S9)| pe Do.
pristinus [Obolus], Matthew [1895a, pp. 121-122]...............-..-..--.-- Trematobolus pristinus.
IMerithre ya [1902629 Gi eee ee Do.
proayia [Acrothyra], Matthew [1902b, pp. 386-388].........--..-.-.--..-- Acrothyra proavia.
Marthewall903%sppoo—00| peer ee ene ase eee e eee ree Do.
proavia [Acrotreta], Matthew [1899b, p. 203]. ..........--..-----------.- Do.
proavia crassa [Acrothyra], Matthew [1902b, pp. 389-390] ......---..-...- Do.
Martiihe ws 9035 p94] sesse= -aeeene eee eee eee Do.
proavia prima [Acrothyra], Matthew [1901b, p. 303].............-.-.-.-.-. Do :
IVerTitve wal 00211389] eae Do
Matthew [1903, pp. 58, 86, and 93].-.-........- Do.
producta [Lingula?], Moberg and Segerberg [1906, p. 63]..----.--.-..-.... Lingulella lepis.
proles [Acrothele], Matthew [1902b, pp. 400-401]............--........--. Acrothele proles. -
Matthew [1903, pp. 60 and 102-103] -.......-.-.....-- Do.
prolificus [Dicellomus], Walcott [1908d, p. 77] -.--.-.--.--.--.-----.---- Dicellomus prolificus.
prospectensis [Iphidea], Schuchert [1897, p. 234]...........-.-.-.----..-- Micromitra (Paterina) prospectensis.

prospectensis [Iphidella], Walcott [1905a, p. 307] -......-.-.-.--------.-- Do.

86 CAMBRIAN BRACHIOPODA.

~ Present reference.

prospectensis [Kutorgina], Walcott [1884b, p. 19]. .......-.-.-..--.--.--- Micromitra (Paterina) prospectensis.
Walcott [1886b, pp. 106-107] ...............-.-. Do.
Wealleoris (MEI, jo; ONO) scscssscsaccsaccsacscans Do.
Protorhyncha? antiquata Schuchert [1897, p. 334]........-..-.--.-.------ Swantonia antiquata.
Protorhyncha? minor Schuchert [1897, p. 334].......-.--.----.---------- Obolella minor.
Protorthis Grabau and Shimer [1907, p. 211]........-.....-.-..-..-..--.- Protorthis.
Hall and Clarke [1892a, pp. 273-274]. ......-....- Save See aie eae Do.
Hall and Clarke [1892b, pp. 589-590]. .....-.......-.--..-....- Do.
Hall and Clarke [1892c, pp. 231-233]. .......-...-..- Su Reeee ae Do.
Wevloon| Me Ose, joo. AKO scooccooesecsovesesuccbossousees Do.
Walcott [1908e, Pl. XI, and pp. 142 and 147]................... Do.
Protorthis billingsi Hall and Clarke [1892a, p. 274]..................---..- Protorthis billingsi.
Hall and Clarke [1892c, pp. 219 and 232]............... Do.
Waillcotita|lS0sar sp pei 2.57)| peepee = ee Do.
(Protorthis) billingsi [Orthis], Wysogérski [1900, p. 227].-................. Do.
Protorthis? eurekensis Hall and Clarke [1892c, p. 232].................... Orusia? eurekensis.
Protorthis helena Walcott [1905a, p. 282]....-.....:......-..-..-.._..-.- Protorthis helena.
Protorthis? hunnebergensis Moberg and Segerberg [1906, pp. 70-71]. ....-- Protorthis? hunnebergensis.
Protorthis levis Walcott [1905a,p. 283]........................++-------- Protorthis levis.
Protorthis latourensis Walcott [1905a, pp. 282-283].....-...-....-..------ Protorthis latourensis.
Protorthis nautes Walcott [1905a, pp. 283-284].-...........-...........--. Nisusia (Jamesella) nautes.
Protorthis? nunnebergensis Walcott [1905a, p. 284]......-.-.....-....---- Protorthis? hunnebergensis.
Protorthis quacoensis Hall and Clarke [1892c, p. 232]...................-- Protorthis quacoensis.
Walcott [1905a, pp. 284-285] .......-..--..-------- Do.
Protorthis spencei Walcott [1905a, p. 285]. .-.......--.------------------ Nisusia (Jamesella) spencei.
Protorthis wingi Walcott [1905a, p. 286]....-.....-.-..--.--------------- Protorthis wingi.
Protonihisispy mundi Waleott||905a,50. 286] eeeeeee see ee ee eeseeeseseeaaes Protorthis sp. undt.
Protorthis (Billingsella) billingsi Grabau and Shimer [1907, p. 211].-.....- Protorthis billingsi.
Protorthis (Loperia) Walcott [1905a, p. 287]. ..-..--.-----.-.--.--.------ Protorthis (Loperia).
Walcott [1908e, Pl. XI, and pp. 142 and 147]......--.. Do.
Protorthis (Loperia) dougaldensis Walcott [1905a, pp. 287-288].........--- Protorthis (Loperia) dugaldensis.
Protosiphon Matthew [1897a, pp. 68-69]................-........-.------ Trematobolus.
Neitiinery [M82a, jp. IDNR)... .<-ecanceqsnscncassosu-s-ee Do.
Protosiphon kempanum Matthew [1897a, pp. 70-71]..-------.-.-.-.------- Trematobolus kempanum.
Wendin? [MERE fo, ISM socesceaasscagscatesssec Do.
pulcher [Obolus?], Hall and Clarke [1892c, pp. 81 and 183]............-- ~.. Botsfordia pulchra.
pulcher [Obolus], Matthew [1889, p. 306].-.....---..--- eee Peat Gate Do.
Matthew [1890, pp. 151-155]..-....-...-.--.--..---.---- Do.
pulcher [Obolus (Botsfordia)], Matthew [1891, p. 148]......---....-..-..-- Do.
Matthew [1892, pp. 62-63]..............--. Do.
Matthew [1902c¢, p. 95]_.---...-...-.---.-- Do.
pulchra [Obolus (Botsfordia)], Matthew [1894, pp. 90-91]................- Do.
Matthew [1895a, pp. 115-121].............. Do.
pumila [Lingulepis], Matthew [1903, p. '75]....-..--.--.--.-.------------ Lingulella (Lingulepis) pumila.
pumpellyi [Billingsella], Walcott [1905a, p. 242].............-.-.-.------ Billingsella pumpellyi.
punctatus [Obolus (Lingulella)], Walcott [1898b, pp. 412-413]. .........-. Lingulella punctata.
pusilla [Kutorgina cingulata], Grénwall [1902, p. 40].......-.-.-.-.-...-- Micromitra pusilla.
Tiina amssony [Si Gsmone2.) | eee Do.
Matley [1902, pp. 146-147]...........-...-- Do.
puteis [Acrothele avia], Matthew [1902b, p. 398] .............----------- Acrothele avia puteis.
Weynlagr |[WIQOS, 15 UOO|. os ss0cssceseas6sccss00006 Do.
pygmea [Lingula], Davidson [1866, p. 53].....----..---.------------------ Lingulella (Lingulepis?) pygmza.
Matleyss [9025 ap Ml gona eee ae a ates Do.
Phas) WSs. O8|eese ssc esa see cee eee ee ee Do.
Salter |['S65) pa WO2|e ease scans eee eee eee Do.
pyxidicula [Acrotreta], White [1874, p. 9]....-.-..--.-.------------------ Acrotreta pyxidicula.
VWvlains [WS 7/5 Tide GBH Escadososaegerooccocsepaccc Do.
Q.
quacoensis [Billingsella], Schuchert [1897, p. 159]...-.--.--.------------- Protorthis quacoensis.
quacoensis [Orthis], Matthew [1886, pp. 48-44]........--.-..........-.-..- Do.
quacoensis [Orthisina], Matthew [1891, p. 131].....-...-....-...-..-..--- Do.
quacoensis [Protorthis], Hall and Clarke [1892c, p. 232].-............-...-- Do.

Walcott [1905a, pp. 284-285]..-...--..--.--------- Do.

SYNONYMIC REFERENCES. 87

Present reference.

quadrilateralis [Obolus (Lingulella)], Walcott [1905a, p. 331]......-..-.--- Lingulella quadrilateralis.
quadrilineata [Acrothele], Pompeckj [1896b, p. 511].....---...--......---- Acrothele quadrilineata.
Qyngloacra, Welkeows MO, 1s eA0) Eoocccossecussseesaesscescoseeesene Be Soe Quebecia.
Walcott [1908e, Pl. XI, and pp. 142 and 145].................-- Do.
Quebecia circe Walcott [1905a, pp. 320-321]....................-..------- Quebecia circe.
quenstedti [Obolus], Hall and Clarke [1892a, p. 243]......----------.------ Obolus apollinis quenstedti.
Hall and Clarke [1892b, p. 559]---.---.---.--------- Do.
Isl ging! Clerks [[IEB Ao. TO, SBW|scosccacosacesesocosoes Do.
Mento (MER, 10. HAO. ccccsesccescoscussagdaoscoars Do.
Witrelgyaliz [AUCE) To). C2llscocsocsscosocecasooosaseocaus Do.
Welkoout (MMEBII9) 19, GED ccsososassacnocossbesecendusa Do.
quenstedti [Obolus apollinis], Mickwitz [1896, pp. 143-145]...-...--...---- Do.
R.
radula [Lingulella], Matthew [1891, pp. 147-148]...........-..-.--.------- Lingulella radula.
radula aspera [Lingulella], Matthew [1903, pp. 204-205].....-....--.-.----- Do.
Rafinesquina? atava Schuchert (1897, p. 338]-.....---------------------- Hoorthis atava.
randomensis [Obolus (Lingulella)], Walcott [1901, pp. 688-689]...........- Lingulella randomensis.
rara [iNisusia], Walcott [1908d, p. 97]-..-..-..-.----..-----.-- lee ee Bee Nisusia rara.
rarus [Acrothele], Walcott [1905a, pp. 303-304]........-....--.----.------- Acrothele rara.
recurva [Acrotreta], Kutorga [1848, pp. 277-278]. -..--..--.---.---------- Volborthia recurva.
recurva [Volborthia], Hall and Clarke [1892a, figs. 261 and 262, p. 249]..... Do.
Hall and Clarke [1892b, figs. 261 and 262, p. 565]. .-. Do.
Hall and Clarke [1892c, pp. 95-96]......------------- Do.
von Méller [1874, pp. 449-452]...........-..--..---- Do.
(Redlichella) [Acrothele], Walcott [1908d, pp. 89-90].....--...--..--.----- Acrothele (Redlichella).
Walcott [1908e, Pl. XI, and pp. 142 and 146].... Do.
refulgens [Monobolina], Matthew [1903, pp. 210-213]. ...............--.-- Obolus refulgens.
refulgens [Obolus], Matthew [1892, pp. 44-45]................-..-.--.--.-- Do.
Wiener IQORS, 19, Wdllbscosccosconece cue oosoesGondedes Do.
refulgens [Obolus?], Mickwitz [1896, pp. 23-24]..............-..-.---.-.-- Do.
refulgens [Obolus (Monobolina)], Matthew [1902c, p. 98].........---.------ Do.
remnicha [Orthis?], Walcott [1899, pp. 451-452, Pl. LXI, figs. 3 and 3a;
PU Xa “fess e=dl]|- oss: -peaaccnaeecneeaseeece Hoorthis remnicha. The text includes

both E. remnicha and E. iddingsi.
Walcott [1899, pp. 451-452, Pl. LXII, figs. la-b] - -.-- Eoorthis iddingsi. The text includes both
H. iddingsi and E. remnicha.

remnicha [Orthis], N. H. Winchell [1886, pp. 317-318]...........--.....--- Eoorthis remnicha.
remnicha [Orthis (Plectorthis)], Walcott [1905a, pp. 268-269]............... Do.
remnicha [Plectorthis], Grabau and Shimer [1907, p. 252]..............-.-- Do.
remnicha sulcata [Orthis (Plectorthis)], Walcott [1905a, p. 269].......-.--- Koorthis remnicha sulcata.
remnicha texana [Orthis (Plectorthis)], Walcott [1905a, p. 270]......--.-.. EKoorthis remnicha texana.
remnicha winfieldensis [Orthis (Plectorthis)], Walcott [1905a, p. 270]....-- EKoorthis remnicha winfieldensis.
retroflexa [Billingsella], Matthew [1903,-pp. 148-151]...........-...--..-- Billingsella retroflexa.
retroflexa [Clitambonites (Gonambonites) plana], Matthew [1895b, p. 267].. Do.
retroflexa [Orthis (Plectorthis)], Walcott [1905a, pp. 270-271].............. Do.
retroflexus [Clitambonites planus], Schuchert [1897, p. 184]..............- Do.
rhea '[Obolus], Walcott [1898b, pp. 387-388].......-..-.-..-.--------.---- Obolus rhea.
richthofeni [Billingsella], Walcott [1905a, pp. 242-243]........-------.--.-- Billingsella richthofeni.
roberti [Lingulella], Matthew [1895b, pp. 256-257].--........--.-.-------- Lingulella (Lingulepis) roberti.
roberti [Lingulepis], Matthew [1903, p. 182]...........-....-....--.------- Do.
robusta [Lingulepis grezwa], Matthew [1903, pp. 57 and 131]......... .----Lingulella (Lingulepis) gregwa robusta.
rogersi [Lingulella], Grabau [1900, pp. 624-625]..............-.-.-.-.------ Obolus (Westonia) rogersi.
rogersi [Obolus (Lingulella)], Walcott [1898b, pp. 413-415].......-.-.....-- Do.
rogersi [Obolus (Westonia)], Walcott [1901, p. 691]......-...-.-.----------- Do.
rokitzanensis [Obolus?], Barrande [1879b, Pl. CXXVI]...---.-..-.------- Obolus rokitzanensis.
romingeri [Billingsella], Walcott [1905a, pp. 248-244]...................-- Billingsella romingeri.
vomingeri [Orthis], Barrande [1848, p. 203].......---..--.----.------------ Do.
Barrande [1879a, Pl. L:XII, figs. m: 1-4]..............- Do.
engimaemiGll -..- 2 sSbescceuscacscoossececcssssccceassse Nisusia (Jamesella) kuthani.
Jet Sh a QHontaa tem se CeBe aE aeae Den acses MEE neebsaHomees Do.

88 - QAMBRIAN BRACHIOPODA.

Present reference.

momin geri |Orthis)cslaee eee eee eeeeee eee eee eee e= ese r ae aeeeeee ee Nisusia (Jamesella) kuthani. -
IN oWallex sears sareieeasneris sae oasis ee ee Do.
Pompeckj [1896b, pp. 513-514]. ......---..-.-.------- Billingsella romingeri.
Wenitzel ganar eeyejs sine ee enisiesicis a.i a clss Se ee Nisusia (Jamesella) kuthani.
rotunda [Lingulepis], Matthew [1903, p. 199]..-...-.-..---..--.----------- Lingulella rotunda.
rotunda [Ungula], Pander [1830, pp. 59 and 163]...........-..--..--.---. Obolus apollinis.
rotundata [Syntrophia], Walcott [1905a, pp. 293— oi RES SAE uaBee SERGI Syntrophia rotundata,
rotundatus [Obolus (Lingulella)], Walcott [1898b, p. 415].....-..----.--..-- Obolus rotundatus.
roualti [Lingula], Bornemann [1891, p. 489]...........-.-.--------------- Kutorgina sardiniaensis.
rowei [Obolus (Lingulepis)], Walcott [1905a, p. 334]......--..-...-..------ Lingulella (Lingulepis) rowei.
rudis [Acrotreta], Walcott [1908d, pp. 95-96].........-.....-.-.---.-.----- Acrotreta rudis.
rugatus [Obolus (Acritis?)], Walcott [1901, p. 694]......-..........----... Obolus (Acritis?) rugatus.
rugosa [Schizopholis], Hall and Clarke [1892a, p. 248]..........-.--.------ Schizopholis rugosa.
Hall and Clarke [1892b, p. 564]....--.....--..------ Do.
TseNll eral Qlerdke MER Re, jo, BB socasssa=so5sacoe55- Do.
Waagen [1885, pp. 7538-754].......--.-------------- Do.
Waagen [1891, Pl. II, figs. 12-14]................---: Do.
rugosicostata [Billingsella exporrecta], Walcott [1905a, p. 236]..---..------- Billingsella exporrecta rugosicostata,
rugosus [Acrotreta ophirensis], Walcott [1902, p. 592].....................-Acrotreta ophirensis rugosa.
Instiallia, \Welkeon ([MOOsr, jo. BIS oo os a cecoocesocosoacccnososecance See ee Rustella.
Walcott [1908e, Pl. XI, and pp. 142 and 143]...............--.- Do.
Rustella edsoni Walcott [1905a, pp. 311-312]...............-..--------- Rustella edsoni.
Ss.
sabrine: [Acrotreta (?)], Matley [1902, p. 143]. .......-..----.---...-.--- Acrotreta sabrinee.
sabrinze [Metoptoma], Callaway [1874, p. 196].....-...-..--.------------ Do.
sabrinee [Obolella], Callaway [1877, p. 669]......-.....--...-..--.---.- Do.
Devic [MCB Ds Aili, scbcedsesaccesceseoescaauene Do.
Hall and Clarke [1892c, p. 103]. - SHE eH OS eee Do.
sabring malvernensis [Acrotreta (?)], Matley [1902, io. 143-144] ote aes Do.
saffordi [Billingsella], Walcott [1905a, p. 244].............-.-.-----.----- Wimanella saffordi.
sagittalis [Acrotreta cf.], Walcott [mew] .....--.-..----.----------------- .-Acrotreta cf. sagittalis.
sagittalis [Linnarssonia], Frech (1897, Pl. IA, fig. 3a]..................--. Acrotreta sagittalis.
Hall and Clarke [1892c, p. 108].......-.....--- Do.
\WWalcorin isa jo, IIe easessoccodssccosesseus Do.
\Wealleoriti: MER, jo. 44M booaesecsseccocsessecaues Acrotreta depressa.
Walcott [1891a, Pl. LX VIII, figs. 2a-d]....-.....Acrotreta sagittalis.
sagittalis [Obolella], Brégger [1882, p. 45]............-..-.----.--2------ Do.
Davadsony [S68 spp. s09—3! 0) ers ee Do.
Davidson) | Si7alesp psa 9—340)| eee nae Do.
IDE yavelstorm |[IESRS jo, CHL a's casnsacoscascasscccscrecc Do.
Wimavarssorny [SiG ppl O—20)| pee eee eee ere Do.
Linnarsson [1879, pp. 27-28]. ...--.-----..--------- Do.
Salter [ilS66a,qp e285) memerosecce sos sees ee seeece ane , Do.
sagittalis [Obolella cf.], Wiman [1902, p. 66]......--..................-- Do.
sagittalis [Obolella (Acrotreta?)], Moberg and Segerberg [1906, p. 64]. ...-- Do.
sagittalis belti [Obolella], Davidson [1871, desc. of Pl. L, figs. 15-17].....--. Acrotreta belti.
sagittalis magna [Acrotreta], Walcott [1902, pp. 595-596]..............-- Acrotreta sagittalis magna.
sagittalis taconica [Acrotreta], Walcott [1902, pp. 596-597]......---------- Acrotreta sagittalis taconica.
sagittalis taconica [Linnarssonia], Walcott [1889b, p. 36].........--.:--.-- Do.
Walcott [1891a, pp. 610-611]. .-.....--.- Do.
sagittalis transversa [Linnarssonia], Frech [1897, Pl. IA, fig. 3b]......-..-- Acrotreta sagittalis transversa,
Walcott [1891a, dese. of Pl. LX VIII,
LileHy eo Babee Hanada aceoKeae cb Do.
salemensis [Billingsella], Walcott [1905a, p. 245]. .........-----.--------- Billingsella salemensis.
salemensis [Orthis], Oehlert [1889, p. 1139]. ........-.....--------------- Do.
\WWeikeouit: [stsi7/, jaya, ISOS. 5 Sooo Sc oddsscestsecosacc Do.
Wealkeonti |WeDila, joo. GIZAGIB |. oe ob os esaesseecscesss Do.
saltensis [Orthis], Kayser [1876, p. 8].-.....--..--.--------------------- Eoorthis saltensis.
Kayser Soicp= 280) ie aaccgeceeec ania sseoe eee ees Do.
saltensis [Orthis (Plectorthis)], Walcott [1905a, p. 271]. ..-...-..----.----- Do.
salteri [Obolella (?)], Davidson [1868, p. 311]. -.....-...---...----------- Obolus (Bréggeria) salteri.

salteri [Obolella], Holl [1865, p. 102].........-...-..--.---+--+----+----- Do.

SYNONYMIC REFERENCES. 89

ealteri [Obolella (?)], Matley [1902, pp. 139-140]........-.------------

salteri [Obolella], Phillips [1871, p. 68]
salteri? [Obolella], Davidson [1866, pp. 61-62]
salteri [Obolus], Brogger [1882, pp. 4445]
salteri [Obolus?], Dall [1870, p. 163]

sandbergi [Billingsella (Otusia)], Walcott [1905a, pp. 246-247]
sandbergi [Orthis (?)], Walcott [1899, pp. 452-453]

sardiniaensis [Kutorgina], Walcott [1901, p. 695]
Schizambon Hall and Clarke [1892a, pp. 253-254]
Hall and Clarke [1892b, pp. 569-570]

Walcott [1884b, pp. 69-70]

Walcott [1884b, pp. 70-71]. -

Nebizamiponia Oehlert i887, pal 266] e-eeee see eae eee eee eae eee ee
Schizopholis Hall and Clarke [1892a, p. 248]. .....-...--.-------------
Hall and Clarke [1892b, p. 564]....-.....-...-.-.--:----

isleyl euavel Clewake (MIVA. (o, BYlooo aac oaosacuosasescsacucec

Oehlerti [88 Gap 267 ieecesacs- a=) mes a2 See eeesieeieeee
Wraacens[iS8ha prio? pees se ae aseee cence eace snes

Walcott [1908e, Pl. XI, and pp. 142 ora 145i bees se eaeee
Schizopholis rugosa Hall and Clarke [1892a, p. 248]. .......-...---.-----
Hall and Clarke [1892b, p. 564]..............-.---

Hialivancdi@lorkey ['892G 3p" 95) see eee eee

Waagen [1885a, pp. 753-754]..........-..--..-.----

Waagen [1891 Pl. II, figs. 12-14]. ............-.-.-

schmalenseei [Acrotreta], Walcott [1902, pp. 597-598]. .....--..-...----
schmalenseei [Obolus (Lingulella)], Walcott [1902, p. 605].........---..
schmidti [Obolus], Mickwitz [1896, pp. 152-154]. .......--....---...---
Schmiditia Balsamo-Crivelli [1863] .--.-..-----.-...---.---------------
Solavnutchiten, DAML MI, to Glo ace cue cave be oeads boseneasdooeseeesearas
EHalliands Clarke) [89 2ar ioe 244 | eee eens epost ae eerie eee

Talal ainél Clemiiee (TIN, jo, HAO. - 5-2 - esecssssceseecseesece

Jalal pyovel Clewdies [WS WO, fo, EBila o os geo neacseseueseccsacssaus

Owiilents MEG, 1, WHOM. aocaccossa-eae-5 e456 PE n ect

Wollooailn [M9 joo. BOAO). soc se ccescuuanssecascessaces

Zittell [NSS pa6G5| Sasser eo see ees = ieee eee eee aiaee

(Schmidtia) [Obolus], Mickwitz [1896, p. 158]. ..........-...-..-------
Wralkeonit [MOL jo. GSBl- = s ocdonsscceceseaceassaas
Walcott [1908e, Pl. XI, and pp. 142 and 144]... .
(Schmidtia) acuminatus [Obolus], Mickwitz [1896, pp. 179-183].......---

(Schmidtia) acuminatus alatus [Obolus], Mickwitz [1896, pp. 183-184]

(Schmidtia) acuminatus humeratus [Obolus], Mickwitz [1896, pp. 184-186]

Maclew.tz4i [A896 yup sel 9) eee eee eee eee ees

salteri [Obolus (Bréggeria)], Moberg and Segerberg [1906, p. 64]..-.--.--
Walcott [1902, pp. 605-606]...............-

salteri var.? [Obolus (Bréggeria)], Westergard [1909, p. 56]....-.--.-----

sandbergi [Orthis], N. H. Winchell [1886, p. 318].....-...-.--..--.--.-
Walkeortib [MOOR , jo. SUM). scoosecoaaccceoecesce
scabrinz [Obolella?], Walcott [1884b, Pl. I, fig. lc]...-......--.---.---

Hall and Clarke [1892c, pp. 113-117]. ..-...-...--.--.----
Walcott [1908e, Pl. XI, and pp. 142 and 146]....-..--.----

Winchell and Schuchert [1895, p. 360]......-..--.-...-.-.--

Schizambon ? esthonia Walcott [new] ....--...-.---.-----------------
Schizambon manitouensis Walcott [new]...--..-..--------------------
Schizambon priscus Matthew [190la, pp. 277-278]. ....-.-------------
Matthews [903 pp S189) peeeee esses eee eee

Schizambon typicalis Hall and Clarke [1892a, p. 253]....--..--..------
Hall and Clarke [1892c, pp. 114, 116, and mel aly

--Dicellomus (in part)

Present reference.

Obolus (Bréggeria) salteri.

Do.

Do.

Do.

Do.

Do.

Do.

Do.

Do.
Otusia sandbergi.

Do.

Do.
Kutorgina sardiniaensis,

Do.
Acrotreta sabrinee.
Schizambon.

Do.

Do.

Schizambon ? esthonia.
Schizambon manitouensis.
Schizambon priscus.

Do.
Schizambon typicalis.

Do.

Do.
Schizambon.
Schizopholis.

Do.

Do.

Acrotreta schmalenseei.

Obolus schmalenseei.

Obolus schmidti.

A genus of the Porifera.

Obolus (Schmidtia).
Do.

and Obolus
(Schmidtia) (in part):

. -Obolus (Schmidtia).

Do.

JK Do.

Obolus (Schmidtia) acuminatus.

(Schmidtia) acuminatus subtriangularis [Obolus], Mickwitz [1896, pp. 186-

TE) nas Mees al ie Aare Ieee. Seen oaie Abireot nha, sania
Schmidtia celata Hall anda@larkey|ilG92a) ps2 44 | nee
Hall and Clarke [1892b, ps 560] ce ose e es eee

Isl gingl Cleimliee |MEBRO. Toc BBlLsccscacesconcessboesees

Wollborthy S69 spe 209-212 ease eee

Do.

90

(Schmidtia) celatus [Obolus], Mickwitz [1896, pp. 159-163]. . Saeae
(Schmidtia) celatus orbiculatus [Obolus], Mickwitz [1896, pp. -168-265.. othe
(Schmidtia) celatus preecisus [Obolus], Mickwitz [1896, pp. 166-167] -.
Schmidtia?? complexus Mickwitz [1896, pp. 19-20]
(Schmidtia) crassus [Obolus], Mickwitz [1896, pp. 187-193]
(Schmidtia) crassus angulatus [Obolus], Mickwitz [1896, pp. 193-194]
(Schmidtia) obtusus [Obolus], Mickwitz [1896, pp. 167-171]
(Schmidtia) obtusus acutus [Obolus], Mickwitz [1896, pp. 172-173]
(Schmidtia) obtusus ellipticus [Obolus], Mickwitz [1896, pp. 177-178]....--
(Schmidtia) obtusus extenuatus [Obolus], Mickwitz [1896, pp. 178-179]... -
(Schmidtia) obtusus latus [Obolus], Mickwitz [1896, pp. 174-175].......-.--
(Schmidtia) obtusus longus [Obolus], Mickwitz [1896, pp. 171-172].....-..
(Schmidtia) obtusus minutus [Obolus], Mickwitz [1896, pp. 175-177]
schucherti [Obolus (Lingulella)], Walcott [1901, pp. 689-690]
Schuchertina Walcott [1905a, p. 323]
Walcott [1908e, Pl. XI, and pp. 142 and ce
Schuchertina cambria Walcott [1905a, pp. 323-324]...
scotica [Micromitra], Walcott [new]
sculpta [Aulonotreta], Dall [1877, p. 16]
Kortorgay [U8S485ppn 282-283) poses eee ae eee
sculptilis [Iphidea (??)], Meek [1873, p. 479]
sculptilis [Iphidea], Schuchert [1897, p. 235]
Walcott [1899, pp. 447-448]....-......-.-....:--------
sculptilis [Iphidella], Walcott [1905a, p. 308]
sculptilis [Kutorgina], Walcott [1884b, p. 20]
sculptilis endlichi [Micromitra], Walcott [1908d, p. 56]
seebachi [Acrotreta], Moberg and Segerberg [1906, pp. 66-67]
Walcott [1902, pp. 598-599]
selwyni [Lingulella], Matthew [1895b, pp. 255-256]
Marthe wa [o035ipp62—03)|sasseeeeeeee eee eee tee eeeae
Matthew [1903, pp. 116-123].-........-...--.---..---
septalis [Obolus (Lingulella)], Walcott [1905a, p. 331]
sequens [Lingulella (Lingulepis) acuminata], Walcott [1908d, p. 7
sera [Acrothyra (signata)], Matthew [1902b, pp. 383-384]
sera [Acrothyra signata], Matthew [1903, p. 56]
Matthew [1903, pp. 87-88]
shantungensis [Acrotreta], Walcott [1905a, pp. 301-302].................--
shelbyensis [Wimanella], Walcott [1908d, p. 100]
shensiensis [Obolus], Walcott [1905a, p. 327]
siemiradzkii [Obolus (Lingulella)], Walcott [1901, pp. 690-691]
signalis [Acrotreta], Walcott [1902, p. 599]....-.....-..-..-.-------------
signata [Acrothyra], Matthew [1902b, pp. 381-382]
Matthew [1903, p. 87]
signata [Lingula?], Barrande [1868a, p. 103]
Barrande [1868b, p- 692]
signata orta [Acrothyra], Matthew [1902b, pp. 385-386]
Wientlneyyy |[I08), joe). SYN) 2 ccsecesssoessocsccss
signata prima [Acrothyra], Matthew [1902b, pp. 382-383]
Matthew [1903, p. 73]
(signata) sera [Acrothyra], Matthew [1902b, pp. 383-384]
signata sera [Acrothyra], Matthew [1903, p. 56]
° Matthew (1903, pp. 87-88]..-..-............_..--
signata tarda [Acrothyra], Matthew [1902b, pp. 384-385]...-..-..--.---.----
Matthew [1903, p. 89]
siluricus [Obolus], Eichwald [1843a, pp. 7-8]
Hichwald [1859, Pl. XX XVII, figs. 6 and 7a-b] .-.....--
Hichwald [1860, pp. 927-928]
Mickwitz [1892, p. 60]
Schmidt [1861, p. 218]
Sehmntdit7 SSE oa Beem ees) yaa ess eee eer
Semin Vata [NES 10. Gil bacescscossssonsssseccsoccone-
siluricus [Obolus (Thysanotos)], Mickwitz [1896, pp. 195-199]
similis [Obolus (Lingulella)], Walcott [1898b, pp. 415-416]..............-.
simplex [Lingula], Barrande [1879b, Pl. CIV, figs. v1: 1-4]

“[1908d, p. 7 ites

CAMBRIAN BRACHIOPODA.

Present reference.

--Obolus (Schmidtia) celatus.

Do.
Do.
Obolus compiexus.
Obolus (Schmidtia) crassus.
Do.
Obolus (Schmidtia) obtusus.
Do.
Do.
Do.
Do.
Do.
Do.
Lingulella schucherti.
Schuchertina.
Do.

..-Schuchertina cambria.

Micromitra scotica.

Obolus (Acritis) antiquissimus,
Do.

Micromitra sculptilis.
Do.

Do.
Micromitra sculptilis endlichi.
Acrotreta seebachi.

Do.
Obolus selwyni.

Do.

Do.
Obolus septalis.
Lingulella (Lingulepis) acuminata sequens.
Acrothyra sera.

Do.

Do.

.Acrotreta shantungensis.

Wimanella shelbyensis.
Obolus shansiensis.
Lingulella siemiradzkii.
Acrotreta signalis.
Acrothyra signata.
Do.
Lingulella signata.
Do. .
Acrothyra signata orta.
Do.
Acrothyra signata prima.
Do.
Acrothyra sera.
Do.

Do.

Do.

Obolus (Acritis) antiquissimus.
Obolus (Mickwitzella) siluricus.
Lingulella similis.

Lingulella? simplex.

SYNONYMIC REFERENCES. 91

Present reference.

simplex [Wimanella], Walcott [1908d, p. 101]....-.........-...--.- Al a toe Wimanella simplex.
sinoe [Obolus (Lingulella)], Walcott [1898b, pp. 416-417]-....--....-..----Obolus sinoe.
Siphonotreta Davidson [1853, pp. 131-183].........-.......-------+------- Siphonotreta.
IDewiatelsteyahy WRstisgoneyo)l lace oodsaneoedees osconacoSodaeeeonees Do.
IDewaClksom |MV7, 1s US=NG| sacossessossccecasscoccuacanscse Do.
ID storm, |[TRSEBY, 1s LAW EAI) cc cecncsccseoascesaccnbdsedesoc Do.
Bien alkal [MRO id; OILS oocooe eonoce susoosegsosoncHoaceses Do.
Hall and Clarke [1892a, pp. 252-253]..........-.--.--------- Do.
Hall and Clarke [1892b, pp. 568-569]...........--..-.----.-- Do.
Hall and Clarke [1892c, pp. 110-118]....-..-.-: Fides svar eae 26 Do.
JeremejewalllGoGnppariolandss0)|eaeeeasse eee eee eee eae ishmeseate,
Kutorga [1848, pp. 261-263]........-......--.--.------------Siphonotreta.
Mornisy [i849 ip pr isl5—320))-eeseaceeseee ene ae eee sees Gee eee Do.
Morrisa[li850 Sip aot 0S ceacecsseeceenoceee reece -ccece st near Do.
Oehlert [M887 pel 265] isa2e,- es eaeeeiceeeesee Gers eiee eee Do.
Qiueasieclis |[MEVAL, Too. GISAOVE! -coscosdoosas coe 5 scc0saaasseone Do.
Seebachy[liSGor poate 2. ee = Sees ils cel eee, ee a Do.
Glo Wermnewull B45, To, ANB) }55 eocnsscseseeoosseenecaces eatla Do.
Walcott [1908e, Pl. XI, and pp. 142 and 146] -..-..-......-- Do.
Winchell and Schuchert [1895, p. 358]..........-..----.---- Do.
Poaiiiiell | NEO, jo. GHTATIG||- 22-2 220ccee-ceececosctoossessocse Do.
Siphonotretaec wlan Valeott) [mew] seseeree ces cee esa ceeae see eee Siphonotreta ? dubia.
Siphonotreta ladogensis Jeremejew [1856, pp. 73 and 80] ..---.........-.-- Helmersenia ladogensis.
Siphonotreta unguiculata Davidson [1853, Pl. IX, figs. 261-265, 269, and
ZAAU) Re SERN Se ere telat ety ee SPN ees ete ies Siphonotreta unguiculata.
Davidson [1877, pp. 14 and 15]..............--- Do.
Hichwald [1860, pp. 915-916]..........----..---- Do.
(Coal), io. 2B Leotoacaupesnoeessnocesécosaas Do.
Hall and Clarke [1892a, p. 253]......-.....---.-- Do.
Halivand' Clarkel[892cssorelilill|Saeeee= see Do.
Kutorga [1848, pp. 264 and 284].............--- Do.
Quenstedih [lsiqlhipa 674) pees eese eee eee Do.
Qyncrasweh Mss), DW. WD |esocecoscseascsssesss0 Do.
Selamanclit, MAGI, OD. BU seccosascasasescssc=225>5¢ Do.
de Verneuil [1845, pp. 286-287]...........-...-- Do.
Walloout (MES, (0. Ul bssccgoecosoncscsseeosesss Do.
PAN MED, 19 GHG ocaascocasesocsasasseacesuce Do.
Siphonotreta unguiculata var. a Kutorga [1848, p. 284] -.......-..-..-.-- Do. i
Siphonotreta unguiculata var. @ Kutorga [1848, pp. 264-265] ............-- Do.
Siphonotreta unguiculata var. 7 elongata Kutorga [1848, p. 265].........- Do.
Siphonotreta verrucosa Davidson [1853, Pl. TX, figs. 267 and say eee Siphonotreta verrucosa.
Hichwald [1860, pp. 916-917]-- sean Je CE Do.
Gacell| [M890 aps 222 ses ccmccecmieee ace eee eee Do.
Kutorga [1848, pp. 266-267]-.....-...:----------- Do.
Morris [1849, Pl. VII, figs: 2a-di] -----..-2-.--2---- Do.
Ohurerausiieslts (WSL, To. G4 | caconcasccsesescaooesecco= Do.
Qwenstediy [S8os period |sseaeesee eee eee eee Do.
Sielamoanilis [IMEI 1D. Zils) caccsaasascacsessmsescscecc Do.
de Vernemullli [8455 ps 287|besss 2 see eee Do.
‘sipo [Acrotreta], Matthew [1902b, pp. 406-407].................-.--------- Acrotreta bisecta.
Matthew [1903, pp. 185-186]. ...--- BORER Seen aG Sons Do.
smithi [Obolus], Walcott [1908d, pp. 62-63, Pl. VII, fig. 9a]......-...-.-- Obolus smithi.
Walkeonité [MI Msiel, Il, WUE Wis, Ol bccsesoeseccesoncessecons- Micromitra (Paterina) major.
socialis [Acrotreta], Grénwall [1902, p. 39] ....-.-..---.-...--.-.-------- Either Acrotreta schmalenseei or A. socialis.
(See p. 712.)
Linnarsson [1876, pp. 16-18] ....--.----.--..--.-------Acrotreta schmalenseei.
Linnarsson [1877, p. 374] .----------------------------Hither Acrotreta schmalenseei or A. socialis.
(See p. 712.)
von Seebach [1865, p. 341]......------..-.-...-.------Acrotreta socialis.
Walloon, [MOO2, join. SOTO 22 onsoceceeesscessosscece Do.
Wollleriuis) [MGS 70, Gel pocacaécsconamnencossassssssaece Acrotreta schmalenseei.
socialis [Acrotreta cf.], Brégger [1882, pp. 46-47, Pl. X, figs. 2, 2a-b].....-. Acrotreta carinata.
Brégger [1882, pp. 46-47, Pl. X, figs. 3 and 4].--... Not referred in this monograph.

Matley [1902, pp. 144-145] .....................--- Acrotreta sabrine.

92 CAMBRIAN BRACHIOPODA.

Present reference.

socialis [Acrotreta cf.], Matthew [1902b, pp. 392-394]..........--..--..--.- Acrotreta sp. undt., not A. socialis.
Matthew [1903, pp. 183-185]...........-.---.------ Do.
solidus [Obolus (Leptembolon) lingulzformis], Mickwitz [1896, pp. 204—

2.0 5] ee ie) Sie ae Nee ge Ate erie epee StS a 2405) OREN Lingulella (Leptembolon) linguleformis.
spatulus [Obolus (Lingulella)], Walcott UE 19), GU (pesca asagsoecccas Lingulella (Lingulepis) spatula.
spencei [Protorthis], Walcott [11905a, p. 285]-.---...-.--.-..-..---------- Nisusia (Jamesella) spencei.
Spherobolus Matthew [1895b, p. 263] -..--............--....------------ Obolus (Lingulobolus).
Spheerobolus spissus Grabau [1900, pp. 622-623] .......-.....-..-------: Obolus (Lingulobolus) spissus.

Matthew [1895b, pp. 263-266].-..-...-...-.-------- Do.
spinosa [Acrotreta], Walcott [1905a, p. 302]....................---------- Acrotreta spinosa.
Spirifera? lenticularis von Buch [1834, p. 48]...-.-.....--.-------------- Orusia lenticularis.
spissa [Lingulella?], Billings [1872b, pp. 468-469] .........-..-.--.--:---Obolus (Lingulobolus) spissus.
Ballin) [il Siow 6/68) Neeser see eee eae Do.
Billings [1882, p. 15]-. sf PO Rae Ago Do.
spissus [Obolus (Lingulobolus)], Walcott [1898a, . p. 397]... eee GES acpeeae Do.
spissus [Spheerobolus], Grabau [1900, pp. 622-623] ...:...-.....--.--.---- Do.
Matthew [1895b, pp. 263-266]...-..-....-.------- Do.
spurri [Acrothele], Walcott [1908d, pp. 86-87]-..-....-.--.-..-:.-------- Acrothele spurri.
squama [Davidsonella], Waagen [1885, pp. 766-767]-.--..--.-...--------- Neobolus warthi. s
squamosa [?Lingula], Davidson [1866, p. 41].-......-...-..-.--.--------- Lingulella (Lingulepis?) squamosa.
squamosa [Lingula], Holl [1865, p. 102].....................-..--...---- Do.
starri [Lingulella], Matthew [1891, pp. 146-147].........-.--.--.-.------ Lingulella (Lingulepis) starri.
starr [linbulepis], Matthew [19035 p) U95]-----22---.-------------------- Do.
starri exigua [Lingulepis], Matthew [1903, pp. 197-198]...-.....-.......--Lingulella (Lingulepis) exigua.
starri minor [Lingulella], Matthew [1892, pp. 58-59].......--....--..---.- Lingulella minor.
starri var. [Lingulepis], Matthew [1903, pp. 193-197]...........-.--.----- Lingulella (Lingulepis) exigua.
stissingensis [Iphidea], Schuchert [1897, p. 234].-..............-...-.--. Micromitra (Paterina) stissingensis.
-stissingensis [Iphidella], Walcott [1905a, p. 308].....---........-...--.- Do.
stissingensis [Kutorgina], Dwight [1889, pp. 145-147]...................- Do.
IDytstors [EOL jo. MOH). .2cs5ceccssnesscescoocse Do.
stissingensis ora [Micromitra (Paterina)], Walcott [new]---.-..---.-------- Micromitra (Paterina) stissingensis ora.
stoneana [Lingulella], Hall and Clarke [1892c, Pl. II, figs. 9-11]..........- Obolus (Westonia) stoneanus.
Weller, [S03 sweet eae Bees moe Do.
Whitfield [1882, pp. 344-345]..........-..-------:- Do.
stoneanus [Obolus (Westonia)], Walcott [1901, p. 691].....-.............. Do.
striata [Billingsella], Walcott [1905a, p. 245].-...- he Ly eel. Sinaia AeA Billingsella striata.
Strophomena atava Matthew [1893b, pp. 102-103].............-..-.------ EKoorthis atava.
Strophomena? atava Moberg and Segerberg [1906, Pl. II, figs. 7, 7a-b].-.- Do.
Strophomena (Eostrophomena) Walcott [1905a, p. 256] -.....----..----.- Eostrophomena. ~

Strophomena (Eostrophomena) elegantula Walcott [1905a, pp. 256-257] ..Eostrophomena elegantula.
Strophomena (Hostrophomena) walcotti Moberg and Segerberg [1906, p. 71]. Do.

strophomenoides [Orthis lenticularis], Matthew [1892, p. 49].........-.--- Orusia lenticularis.
Matthew [19038, p. 217].-......----. Do.
stuarti [Micromitra (Paterina)], Walcott [1908d, p. 58].-.---..-.-.--.------ Micromitra (Paterina) stuarti.
subconica [Acrotreta], Davidson [1853, Pl. IX, figs. 271-275]........-...-- Acrotreta subconica.
Iunordeg, (EVA, 19) AUD lscanemonaesesasbechanaesaseo Do.
Meek: [1873;p. 463] bsesc-e-esaee ese eee soceseees Acrotreta attenuata (in part), A. attenuata
var. (in part), and A. idahoensis (in part).
Quenstedii[885; soe (ool eee reese eee eee er Acrotreta subconica.
Von seebach' [il S65 sips o4li|passeeeee ene seeie es oasee Do.
Walcott [1902, pp. 600-601]. ......-...........-.-- Do.
subquadrata [Nisusia (Jamesella) perpasta], Walcott [1905a, p. 255]....-.-- Nisusia (Jamesella) perpasta subquadrata.
subquadrata [Orthis perpasta], Pompeckj [1896b, p. 516]. ...-...--..---.- Do.
subsidua [Acrothele], Beecher [1891, Pl. XVII, fig. 12]....-............... Acrothele subsidua.
Grabau and Shimer [1907, p. 200].............------ Do.
Hall and Clarke [1892c, pp. 100 and 103]......---..-- Do.
Wilner? |[NOORXE, fo, WNO|o casceascscsacsecasceescoss Do.
Werte [IGOR (o>, WOBIscascscedoeseseccoccssoceess Acrothele spurri.
Walcott [1886b, pp. 108-109, Pl. IX, figs. 4a-c]....-. Acrothele subsidua. The paragraph on

page 109 includes reference to this spe-
cies and to Acrothele spurri.
Walcott [1886b, p. 109, Pl. IX, fig. 4]................Acrothele spurri. The paragraph on page
109 includes reference to this species and
to Acrothele subsidua.

SYNONYMIC REFERENCES. 93
Present reference.
subsidua [Acrothele], Walcott [1891la, p. 608, Pl. LXX, fig. 1]...--..--....- Acrothele spurri. The text includes refer-
ence to this species and to Acrothele sub-
sidua.

Walcott [189la, pp. 608-609, Pl. LXX, figs. la-c]....Acrothele subsidua. The text includes
reference to this species and to Acrothele

spurri.
Wilber [ASSO 474s ses ee een een ee Se at ae te Acrothele subsidua.
sHosGhie, [AGRO WVlavine |Z 10); Olls o2s0ceseccsecsc-sssccosocesace Do.
Wat |[ME, OD: CHENG | coenacaccsssascacsacgsesee Do.
subsidua hera [Acrothele], Walcott [1908d, p. 87]_..-...--.-------.------ Acrothele subsidua hera.
subsidua leevis [Acrothele], Walcott [mnew]............-.--.....--.-.----- Acrothele subsidua leevis.
subtriangularis [Obolus (Schmidtia) acuminatus], Mickwitz [1896, pp. 186-

S| RRR eee tn par ae ees tn SANS Sayles aya raat. do A ae Obolus (Schmidtia) acuminatus.
sulcata [Acrotreta idahoensis], Walcott [1902, p. 588].--..--....-.--------- Acrotreta idahoensis sulcata.
guieniia (Creme, itelay ele [EYE to) AiEl|]scconceabe2s0-e02052eacs5552s05e> Siphonotreta unguiculata.
suleata [Orthis (Plectorthis) remnicha], Walcott [1905a, p. 269]......-..--- EHoorthis remnicha sulcata.
sulcatus [Discinopsis], Walcott [1906, pp. 568-569].-..............-.------ Discinopsis? sulcatus.
Superba [Iphidea], Walcott [1897b, p. 711]. 2..-2--..-..-....-......--..--- Micromitra (Paterina) superba.
swantonensis [Iphidea], Grabau and Shimer [1907, p. 201]--.--.---.--.---- Micromitra (Paterina) labradorica swanton-

ensis.
swantonensis [Iphidea labradorica], Schuchert [1897, p. 234]....-......--.- Do.
swantonensis [Iphidella labradorica], Walcott [1905a, p. 307]......-.-.----- Do.
swantonensis [ Kutorgina labradorica], Walcott [1890b, p. 36]....-.-------- Do.
: Walcott [189ila, jp: 609)--2----2---2- Do.
Swamioain, Wealleoit [IOOsA, jos 2X6] cessa co coccascaneasacsoccseseacsesess5 Swantonia.
Walcott [1908e, Pl. XI, and pp. 142 and 148]..................- Do.
Swantonia antiquata Walcott [1905a, pp. 296-297]....-............-...-.-- Swantonia*antiquata.
Swantonia weeksi Walcott [1905a, p. 297]..--........-.------------------ Swantonia weeksi.
Syntrophia Grabau and Shimer (1907, p. 270]...........-..-..-.-...-+-- Syntrophia.
Talal ayo! Clara [Mee 70. AIO) ceccascncasa5ao0s00csss20c00cee Do.
Halland Clarke) [i'893by pps 206-2118) Baeseeese esses sees eee Do.
laleiil aya! Chane | MSO, To). SRB Sssoascoagocnaceasecsascesce=ce Do.
Walcott 9 0barsppe288—780) Peeseeen see ree eee ee nears Syntrophia (in part) and Huenella (in part).
Walcott [1908é¢, Pl. XI, and pp. 142 and 148]...............-.- Syntrophia.
Syntrophia abnormis Walcott [1905a, pp. 289-290]. .........-.-.-.---.--- Huenella abnormis.
Syntrophia alata Walcott [1905a, p. 290]-- ae _.---.--------syntrophia alata.
Syntrophia barabuensis Hall and Clarke [1893b, p. 216)... LASS cathy) hoes Moe enero e Syntrophia barabuensis.
Walcott [1905a, pp: 290-291]... 22222-2222 22 2222: Do.
Syntrophia billingsi Walcott [1905a, pp. 291-292].................-...-..- Huenella billingsi.
Syntrophia calcifera Grabau and Shimer [1907, p. 271].-.---..-..-.-..---- Syntrophia nundina.
Syntrophia? calcifera Hall and Clarke [1893b, p. 218]............-.-.-.-- Syntrophia calcifera.
Syntrophia cambria Walcott [1908d, pp. 106-107]. ......-........--...-.. Syntrophia cambria.
Syntrophia campbelli Walcott [1908d, pp. 107-108]. .....-.....-.....--.- Syntrophia campbelli.
Syntrophia lateralis Hall and Clarke [1892c, p. 270]...--........-.-- gl ae Syntrophia lateralis.
Isleulll ayayol Cllewakes [UBIO > BUN |.2osssasessss2se55s502 Do.
Tale! [US 10> BBY ||sooanocancencsses 2 US ee Do.
Syntrophia nundina Walcott [1905a, p. 292]................-------------- Syntrophia nundina.
Syntrophia orientalis Walcott [1905a, p. 292].............--.-..--...----- Huenella orientalis.
Syntrophia orthia Walcott [1905b, pp. 11-12]............-............... Syntrophia orthia.
Syntrophia primordialis Hall and Clarke [1893b, p. 218]......-...-.------ Syntrophia primordiali:.
Wall@arits, MOOS), 19> 29) pssocasesoccousceesonsedses Do.
Syntrophia primordialis argia Walcott [1905a, p. 293].....-..-...-.------- Syntrophia primordialis argia.
Syntrophia rotundata Walcott [1905a, pp. 293-204]_.-.-.-.--...-..-------- Syntrophia rotundata.
Syntrophia texana Walcott [1905a, p. 294)]..-....---...-.-_....--.---.---- Huenella texana.
Syntrophia texana leeviusculus Walcott [1905a, pp. 294-295] .............- Huenella texana leviusculus.
Syntrophia? unxia Walcott [1908d, pp. 108-109]........-.........--.----- Syntrophia? unxia.
T.
taconica [Acrotreta sagittalis], Walcott [1902, pp. 596-597]...............-- Acrotreta sagittalis taconica.
taconica [Linnarssonia], Oehlert (1889, p. 1138]. ..............-.---.-.--- Do.
Waleotti[1S8i7 spp. 189=190]es == ese ss25 22 sea ee Do.
taconica [Linnarssonia sagittalis], Walcott [1889b, p. 36]...-.....-..-..--- Do.
Walcott [1891a, pp. 610-611]............ Do.

tarda [Acrothyra signata], Matthew [1902b, pp. 384-385]. ...............- Acrothyra sera.

94 CAMBRIAN BRACHIOPODA.
Present reference.
tarda [Acrothyra signata], Matthew [1903, p. 89]..--.....-...---.--------- Acrothyra sera.
tarpa [Obolus (Lingulella)], Walcott [1898b, pp. 417-418].....--.---..---- Lingulella tarpa.
tatei [Orthis (?)], Etheridge, jr. [1905, p. 249] .......-......-...---------- Hoorthis tatei.
Mellinomiya McCoys [Sos ips 274 see eee eee eee enne sere: eee ae eee Lingulella.
Tellinomya lingule-comes McCoy [185la, p. 56]....--..--..------------- Lingulella davisi.
Saltiersase memes ciate mages oat 2c.c AC Raye Does not equal Lingulella davisi.
Tellinomya lingulicomes McCoy [1854, p. 274]......-..--.-.--.---------- Lingulella davisi.
tennesseensis [Linnarssonella], Walcott [1902, pp. 604-605]...-.-...--..--- Linnarssonella tennesseensis.
Terebratula Eichwald [1840, p. 1388 (24)]-........-....------------------ Siphonotreta (in part).
Bichwald! [1843 bss palo] Beem eee ee eee aero aoe eee Siphonotreta.
Terebratula unguiculata Hichwald [1840, pp. 138-140 (24—26)]. ...-...---- Siphonotreta unguiculata.
: Bichywaldl(lg42 sips 145] pseeeeeseeseeeee ase sacs Do.
Terebratula verrucosa Eichwald [1840, pp. 140-141 (26-27)]...-..-----.--- Siphonotreta verrucosa.
tetonensis [Acrotreta microscopica], Walcott [1902, p. 590].......-.--.---- Acrotreta microscopica tetonensis.
tetonensis [Obolus], Walcott [1901, p. 684]..................------------- Obolus tetonensis.
\Weileoii [Osh To. B4/lbesaceaaccsopeocaaceuoneseesso Do.
tetonensis leda [Obolus], Walcott [1908d, p. 63]...........--..----------- Obolus tetonensis leda.
tetonensis ninus [Obolus], Walcott [1905a, p. 328]...........-.----------- ‘Obolus tetonensis ninus.
texana [Lingulella], Walcott [1908d, p. 71]...-....--..-.---------------- Lingulella texana.
texana [Orthis (Plectorthis) remnicha], Walcott [1905a, p. 270].....-...--- Koorthis remnicha texana.
texana [Syntrophia], Walcott [1905a, p. 294]..............-..-..--...--- Huenella texana.
texana leviusculus [Syntrophia], Walcott [1905a, pp. 294-295].........-.- Huenella texana leviusculus.
themis [Obolus (Westonia)], Walcott [1905a, pp. 336-337]. ......-.---..-- Obolus (Westonia) themis.
thyone [Eoorthis], Walcott [1908d, pp. 105-106]...........-..-..-..-....- EKoorthis thyone.
HMongsenovoies, /NMorerns) (MG, jo, @s|be oss 5e-5sesceseeesosceesensossscuessccos A genus of the Gastropoda.
(Thysanotos) [Obolus], Mickwitz [1896, pp. 194-195].....................- Obolus (Mickwitzella).
(Thysanotos) siluricus [Obolus], Mickwitz [1896, pp. 195-199]. . . . .......-Obolus (Mickwitzella) siluricus.
(Thysanotus) [Obolus], Walcott [1901, p. 683]..................-....-...- Obolus (Mickwitzella).
torrentis [Leptobolus], Matthew [1903, pp. 74-75]......-...-..---..------ Lingulella torrentis. ,
torrentis [Obolus], Matthew [1902c, p. 94]...-..-...-..--..------------- Obolus? torrentis.
Matthew) (903) MoeiG] wer eee ceceeee essen aaa Do.
transversa [Linnarssonella], Walcott [1908d, p. 92]..--..--..--...--..-.-- Linnarssonella transversa.
transversa [Linnarssonia], Hall and Clarke [1892a, Pl. III, figs. 22 and 23]. Acrotreta sagittalis transversa.
Hall and Clarke [1892c, p. 108]. ...--..-...--.- Do.
WiEndoey WIS, D> Ble coscss2o2as0052525s2c05- Do.
Matthews [lS 9oan os 25] Bees sees esse ee eens Do.
Walloon MGI, Tob WU |, os cea scadeccoeassed eye Do.
transversa [Linnarssonia sagittalis], Frech [1897, Pl. IA, fig. 3b]........-..- Do.
Walcott [189la, desc. of Pl. LX VIII,
IS, CA, Os Byael Well) Sasscscacceseanc Do.
transversa [Nisusia festinata], Walcott [1905a, p. 251]...............-...-. Nisusia festinata transversa.
transversa [Obolella], Hartt [1868, p. 644].....-.......-....-..--..---.-- Acrotreta sagittalis transversa.
(lanttsilS7S snow G44] epson ccise ce ooeisieseia ae eee Do. '
TFA iGt[LG Ouest ae GAA Mee one eee ee te RR 5 Do.
Wallcotti[l884aprlG]t sme emaasnse acco aceasta Do.
transversa [Orthisina?], Walcott [1886b, p. 121]......-..--..---.----.----- Nisusia festinata transversa.
Walkeorit [DEE (O. GUB|o co acencosssneoesssensesss5 Do.
transversa [Ungula], Pander [1830, pp. 59 and 154, Pl. III, fig. 24]. .....-- Obolus apollinis quenstedti.
Pander [1830, pp. 59 and 163, Pl. XX VIII, figs. 7a—b
and Saab ajecs.oe Seaweed cen eee ears e EINE Obolus apollinis. The text includes also
Obolus apollinis quenstedti.
Trematis pannulus White [1874, p. 6]..-------...----------------------- Micromitra (Iphidella) pannula.
\Wiidanties (METS 102 HEB csoonesscesossseussassscqseec Do.
Trematobolus Hall and Clarke [1892a, p. 252]............-..--..--..----- Trematobolus.
TBkeUL choyel Clarkes [EGA To: WOS|o soo bis oeaesesas-sbense=ssc Do.
Moartithe wa [89 3areppa216—2119]| mere e eee eee eee Do.
Wleniileveny [ERE oo. GE=WU|o os sels sccessaqocscesessse-sescce Do.
Martine wal 89 5a spp unl 225) see eee eee eee eens Do.
Walcott [1908e, Pl. XI, and pp. 142 and 146].............-- Do.
Trematovolus excelsis Walcott [1908d, pp. 80-81]. .....----.------------- Trematobolus excelsis.
Trematobolus insignis Hall and Clarke [1892a, p. 252]. ..................Trematobolus insignis.
Hall and Clarke [1892b, p. 568]... .--.-.---------- Do.
Matthew [1893a, pp. 276-279]. ...-....----:--.--.- Do.

Matthew [1894, pp. 88-90]. .....-.-..------------- Do.

SYNONYMIC REFERENCES. 95

Present reference.

Trematobolus insignis Matthew [1895a, pp. 122-125]..................... Trematobolus insignis.
Wienndieny |MII©, > ODl|ccececeacsecssesccuncsesace Do.
Matthew {1898} jp. 35]2------.------ Bearers sient Do.
triangularis [Obolus], Mickwitz [1896, pp. 145-147]...........-....----.-- Obolus triangularis.
Moberg and Segerberg [1906, p. 65]. ..--.----.------ Do.
Westemefingl (MOS) Oo. BOlle occas ecscscccusccsnsscesc Do.
triangularis [Ungula], Pander [1830, pp. 59, 154, and 163].............-..- Obolus apollinis.
triangularis inornatus [Obolus], Mickwitz [1896, pp. 148-149]. .....-.--.-- Obolus triangularis.
triparilis [Obolus], Matthew [1902c, p. 94]......--.-.--.---------+------ Lingulella triparilis.
triparilis [Obolus (Eoobolus)], Matthew [1903, pp. 136-137]...........-..- Do.
Triplecia? calcifera Hall and Clarke [1892c, p. 270]....-...--.----.--.--Syntrophia calcifera.
Triplecia? primordialis Hall and Clarke [1892c, p. 270]........--.--.----- Syntrophia primordialis,
Triplesia calcifera Walcott [1884b, pp. 75-76].......-.-..---------------- Syntrophia nundina.
Triplesia lateralis Whitfield [1886, p. 303]............./......-...------ Syutrophia lateralis.
Triplesia primordialis Whitfield [1878, p. 51]. ..........-..-...-.-------- Syntrophia primordialis.
VWivdmuitermie lial (USS, To, IIs o ca cnaconcoogsusdascssscss Do.
tritavus [Leptobolus atavus], Matthew [1903, p. 109]..-...........---... Lingulella torrentis.
tullbergi [Orthis (Plectorthis)], Moberg and Segerberg [1906, p. 69]..---.-- Eoorthis tullbergi.
Walcott [1905a, p. 271]. ---2--.-4-------- Do.
tumida [Lingulella], Matthew [1899b, p. 200].......-..---..-...--..------ Lingulella tumida.
Mattltewa [903s dais yes sais ire cates ere ice eee Do.
turneri [Acrothele], Walcott [1908d, pp. 87-88].......--..-.---.---------- Acrothele turneri.
typicalis [Schizambon], Hall and Clarke [1892a, p. 253]......--..---.-- Schizambon typicalis.
Hall and Clarke [1892c, pp. 114, 116, and 117). - Do.
Walcott [1884b, pp. 70-71]... -- Boueisisscee eee Do.
U.
ulrichi [Acrotreta], Walcott [1908d, pp. 96-97].....-....----------------- Acrotreta ulrichi.
undosa [Kutorgina], Moberg [1892b, p. 112].............-..--...-..--..-- Micromitra (Paterina) undosa.
unguiculata [Crania], Eichwald [1829, p. 274]............---.------------ Siphonotreta unguiculata.
unguiculata [Siphonotreta], Davidson [1853, Pl. LX, figs. 261-265, 269, and
27 OR Be MARRS oe oh cee es chien Do.
Davidson [1877, pp. 14 and 15]............-.- Do.
Eichwald [1860, pp. 915-916]. ..........-.-.. Do.
Gagell [MS90n p23. sie ns Bee Saepcise eee eee Do.
Hall and Clarke [1892a, p. 253]....-...------ Do.
Hall and Clarke [1892c, p. 111]....-....-.-..-- Do.
Kutorga [1848, pp. 264 and 284]............-- Do.
@uenstedty S75 pa 674 sees seeeeae eee eee Do.
Quenstedt [1885, p. 755]. ....---------------- Do.
Schncni de [ISGIe Mol Sie se os ee Do.
de Verneuil [1845, pp. 286-287]...........--.- Do.
Welloarne |[iete0), Tos WG)|-cacsoacsceseescccecess< Do.
PAiiticll (MEO, Ds GHG) .cossaccoasetoseoonsonace= Do.
unguiculata var. ¢ [Siphonotreta], Kutorga [1848, p. 284]............-...- Do.
unguiculata var. 8 [Siphonotreta], Kutorga [1848, pp. 264-265]............ Do.
unguiculata var. 7 elongata [Siphonotreta], Kutorga [1848, p. 265].....-...- Do.
unguiculata [Terebratula], Hichwald [1840, pp. 138-140 haa Skee eters Do.
Hichwald [1842, p. 145]... eee See se Gone Do.
unguiculus [Lingulella], Salter [1866a, p. 285]........-..-..-.-----..---- iophayguileile ferruginea.
Uru, IDEN (BSH, Ws WBllsatesaesccsca seas saacesuasggcbeonaessaoseedoreas Obolus.
TE evoke [RO fo). BBs |oonesonnccesedocausoosqaousscsssboscsuese Do.
Ungula convexa Pander [1830, pp. 59 and 163]......-...-.-----.--------- Obolus apollin’s quenstedti.
Ungula ovata Pander [1830, p. 59, Pl. XXVIII, figs. 6a-b]....-.......--- Obolus (Schmidtia) celatus.
Pander [1830, pp. 59 and 154, Pl. EI, fig. 23]. ......-...... Obolus apollinis.
Ungula plana Pander [1830, pp. 59 and 163]..............-.......--..--.- Do.
Ungula plana or convexa Pander [1830, p. 163].-.......-..--.-.---------- Do.
Ungula rotunda Pander [1830, pp. 59 and 163]........-.-..--..---.------ Do.
Ungula transversa Pander [1830, pp. 59 and 154, Pl. III, fig. 24] -........ Obolus apollinis quenstedti.
Pander [1830, pp. 59 and 163, Pl. XXVIII, figs. 7a-b
Env l(c) Se ae ae Are eae oats ee SR Cee RA Obolus apollinis. The text includes also
Obolus apollinis quenstedti.
Ungula triangularis Pander [1830, pp. 59, 154, and 163] .................- Obolus apollinis.

uayeqeuls, (Ortlowis] |, yore IBiuvelai |[SZNE jojo. Wie seac = eee e a Soe ceeseeoeoscuoqeses Do.

96 CAMBRIAN BRACHIOPODA.

Wrnverialivera Vor, 1Syukelm [MVE TO, Wiscooocesccsccoccudasscsassosas
Pander 830 ppeo-—)5 Ses ee ee eeeeee eee eee eee
Quenstedt [1837, pp. 143-145].....-.......----------

Ungulites Quenstedt [1885, p. 756]......---..-..--.......--.--

Ungulites apollinis Quenstedt [1885, pp. 755 and 756]. ....-.---

Cnr SERS eae Obolus apollinis quenstedti.

unxia [Syntrophia?], Walcott [1908d, pp. 108-109].............-

upis [Obolus (Lingulella)], Walcott [1905a; pp. 331-332].......-

uplandensis [Acrotreta], Walcott [1905a, p. 302]....... Rn reeeer

uplandica [Acrotreta], Wiman [1902, p. 54]...-................-

uplandica limonensis [Acrotreta], Walcott [1905a, p. 303].-.------

urania [Linnarssonella], Walcott [1908d, pp. 92-93]..-...--.....-

utahensis [Iphidella labradorica], Walcott [1905a, p. 306]-...-..--

Ungulites sp. Quenstedt [1837, pp. 143-145]. ................-

utahensis [Nisusia (Jamesella)], Walcott [1905a, pp. 255-256]... .
utahensis [Otusia], Walcott [mew]-...--.......--...----.....-

Present reference.

viper Do.
Toes Obolus apollinis.

A datas fe Syntrophia? unxia.

Beret ....-Lingulella upis.

Eee eee Acrotreta uplandica.

ay Do.

SSIS Acrotreta uplandica liméensis.
Lastes ey see Linnarssonella urania.

See ee Micromitra (Paterima) labradorica utahen-

sis.
SadeGeene Nisusia (Jamesella) utahensis.
eS Otusia utahensis.

Vv.
varians [Discina], Barrande [1868a, pp. 103-104]. ................-...--.. Orbiculoidea varians.
Beyeracle |WAGIO, 19, GQLlo cs casescasasssnsesssseeanesses Do.
Rompecksyi [So 6anp 4 |s-ssececreeeeaeeeeee eee cee eee Do.
vaticina [Orthisina], Mallada [1875, p. 32]-...........-..-..2..2-.--1.---- Nisusia? vaticina.
de Verneuil and Barrande [1860, pp. 533-535]. .-....-- Do.

ventrosus [Obolus (Acritis) antiquissimus], Mickwitz [1896, pp. 213-214]. .-Obolus (Acritis) antiquissimus.
eee Obolella vermilionensis.
eta eee eee Huenella vermontana.

vermilionensis [Obolella], Walcott [new] .-..---..---.--------

vermontana [Huenella], Walcott [new] -.-...---.--.----------

verrucosa [Siphonotreta], Davidson [1853, Pl. IX, figs. 267 and aa Beers Siphonotreta verrucosa.

Hichwald [1860, pp. 916-917].-

Cersell (M0, Os ZAlpcocsacscdanacoues

Kutorga [1848, pp. 266-267]. ....--.-

Morris [1849, Pl. VII, figs. 2a-d] ..--.

-Quenstedt [1871, p. 674].-.---.-------

Quenstedt [1885, p. 755].-..-..------------------

Schmaiditii[US6I yon 28a esos see eee

de Verneuil [1845, p. 287].......-.--

verrucosa [Terebratula], Hichwald [1840, pp. 140-141 (26-27)]. -
villaboimensis [Acrothele], Delgado [1904, p. 365]---..-..-----
volborthi [Obolus], Mickwitz [1896, pp. 155-157]-.......-...--

Do.

Bas coe Suse Do. *
Site ts See Do.
IOS beard Do.
eo ere Do.

Do.

BB RRO HS Ms Do.
ROP ates Do.

Se) eee nar Do.

es eee Acrothele villaboimensis.
eneasesees Obolus yolborthi.

Volborthia Hall and Clarke [1892a, p. 249].....-........--..--..--...--.- Volborthia.
Teteyhl eyavel (Clewaxe |My, 10). GDI] ssccoqsoocesesasceesocscsoues Do.
Hall and Clarke [1892c, pp. 95-96].........-..---..-------.--- Do.
von Moller (11874, pp: 449-452]. 2.22252. see tee eee Do.
Walcott [1908e, Pl. XI, and pp. 142 and 143] ................- Do.
Volbor thia recurva Hall and Clarke [1892a, figs. 261 and 262, p. 249].....-. Volborthia recurva.
Hall and Clarke [1892b, figs. 261 and 282, 1D: HGS]. s2 50 Do.
Hall and Clarke [1892c, pp. 95-96]. - Remit ete Do.
von Mller [1874, pp. 449-452]..-.......-.-..--------- Do.

Ww.

walcotti [Strophomena (Eostrophomena)], Moberg and Segerberg [1906,

wanniecki [Lingulella], Redlich [1899, p. 7]..---.--.-..-------
wanniecki [Obolus (Lingulella)], Walcott [1905a, p. 332].......--......-.--
wapta [Micromitra (Paterina)], Walcott [1908d, p. 59]........--
warthi [Lingula?], Waagen [1885a, pp. 769-770].......-..-----
Waagen [189], Pl. II, figs. 18a—b] ---.:...---....----.--
warthi [Neobolus], Frech [1897, Pl. LA, figs. 5a-b] .........---
Hall and Clarke [1892a, p. 245]...-....-..-
Hall and Clarke [1892b, p. 561]-.....------
Hall and Clarke [1892c, p. 84]. .--.-- Busy ete
Oehlert [1887, p. 1263]...........-..------
Waagen [1885a, pp. 758-759]....--.-------..-
Waagen [1891, Pl. II, figs. 5-9] .....-....--
warthi [Orthis], Waagen [1891, pp. 102-104] Bie Seats HERR

Ess cuiente MUS Eostrophomena elegantula.
Hise teeesee Yorkia wanneri.
edoEG Peat Lingulella wanniecki.

' Do.

hea iy Micromitra (Paterina) wapta.
Melanie ava Sie Lingulella kiurensis.

Do.

Sayan a ONO ENS Neobolus warthi.
s/s hf areeeaae Do.

crud ayaa ale Do.

Ao se Ae Bo Do.

cleat olen ORI Do

sk ONE Do.

Diane Mepee uelinyins Do.

RE ES ne Wynnia warthi.

SYNONYMIC REFERENCES.

Present reference.

wasatchensis [Obolus (Westonia)], Walcott [1908d, pp. 69-70]..-----.-.--.- Obolus (Westonia) wasatchensis.
washingtonensis [Yorkia?], Walcott [1897b, pp. 715-716].............-.--- Yorkia? washingtonensis.
weeksi [Swantonia], Walcott [1905a, p. 297]..................-..--------- Swantonia weeksi.
welleri [Obolus (Lingulella)], Walcott [1902, p. 608].......-..............-Lingulella welleri.
(Westonia) Matthew [1903, pp. 205-206]..........................----.-- Obolus (Westonia).
(Westonia) [Obolus], Walcott [1901, pp. 683 and 691]....................- Do.

Walcott [1908e, Pl. XI, and pp. 142 and 144].-...... Do.
(Westonia) alandensis [Obolus], Walcott [1905a, p. 334]................-- Obolus (Westonia) alandensis.
(Westonia) aurora [Obolus], Walcott [1901, p. 691]...-.........-.-.......-. Obolus (Westonia) aurora.
(Westonia) baltica [Obolus], Walcott [1905a, p. 334]..-.......-...-.-...-- Obolus (Westonia) balticus.
(Westonia) blackwelderi [Obolus], Walcott [1905a, p. 335].........-.-.-.-.Obolus (Westonia) blackwelderi.
(Westonia) bottnica [Obolus], Walcott [1905a, pp. ae ts BASE RES H meat AS Obolus (Westonia) bottnicus.
(Westonia) chuarensis [Obolus], Walcott [1901, p. 691]-- .-------------Obolus (Westonia) chuarensis.
(Westonia) dartoni [Obolus], Walcott [1908d, p. 67]-. ----------------Obolus (Westonia) dartoni.
(Westonia) ella [Lingulella], Grabau and Shimer [1907, p. 193].- Gra Lee erat ac Obolus (Westonia) ella.
(Westonia) ella [Obolus], Walcott [1901, p. 691]...-......-.....-....----- Do.
(Westonia) ella onaquiensis [Obolus], Walcott [1908d, pp. aie Be eae Saad Obolus (Westonia) ella onaquiensis.
(Westonia) elongatus [Obolus], Walcott [1908d, p. 68]... --------------Obolus (Westonia) elongatus.
Westonia escasoni Matthew [1903, pp. 206-209]. . -22--+-+-------------Obolus (Westonia) escasoni.
(Westonia) escasoni [Obolus], Walcott [1901, p. 691]... SHEN cel tapaatl Sue ac ears Do.
(Westonia) euglyphus [Obolus], Walcott [1901, p. 691].-.-......-...-...-. Obolus (Westonia) euglyphus.
(Westonia) finlandensis [Obolus], Walcott [1902, pp. 611-612]---.........-- Obolus (Westonia) finlandensis.
(Westonia) iphis [Obolus], Walcott [1905a, p. 336]..............--.---.-.-- Obolus (Westonia) iphis.
(Westonia?) lamellosus [Obolus], Walcott [1901, p. 691].-....-..-..--...-. Obolus (Westonia?) lamellosus.
(Westonia) notchensis [Obolus], Walcott [1908d, p. 69]......--...........-.Obolus (Westonia) notchensis.
(Westonia) rogersi [Obolus], Walcott [1901, p. 691].----.....-.-..-..-.-.-- Obolus (Westonia) rogersi.

* (Westonia) stoneanus [Obolus], Walcott [1901, p. 691]....--........-.....- Obolus (Westonia) stoneanus.
(Westonia) themis [Obolus], Walcott [1905a, pp. 336-337]....-.-...........Obolus (Westonia) themis.
(Westonia) wasatchensis [Obolus], Walcott [1908d, pp. 69-70]..-..--.......Obolus (Westonia) wasatchensis.
(Westonia) wimani [Obolus], Walcott [1905a, p. 337]...----.....-....-.--.-Obolus (Westonia) wimani.
whiteavesi [Bicia], Walcott [1901, p. 680].....-....--......-..--.--------- Bicia whiteavesi.
whitfieldi [Billingsella], Schuchert [1897, p. 159]...--...-.-.------------- Billingsella whitfieldi.

Walcott [1905a, p. 246].......-.-.-...----.-.---- Do.
whitfieldi [Kutorgina], Walcott [1884b, pp. 18-19]..........-..--.---.---- Do.
wichitaensis [Orthis (Plectorthis)], Walcott [1905a, pp. 271-272] ........-. Eoorthis wichitaensis.
wichitaensis lzeviusculus [Orthis (Plectorthis)], Walcott [1905a, p. 272]... .Eoorthis wichitaensis leeviusculus.
williardi [Micromitra (Paterina)], Walcott [1908d, p. 60].-.....-..--.---.- Micromitra (Paterina. williardi.
willisi [Obolus (Lingulella)], Walcott [1898b, pp. 418-419].-.............-. Obolus willisi.
Wimanella Walcott [1908d, pp. 98-99].....--..---.---------------+------- Wimanella.
Walcott [1908e, Pl. XI, and pp. 142 and 148].........-...-....- Do.
Wimanella inyoensis Walcott [1908d, p. 99]---.-..-----.-.-.-------------- Wimanella inyoensis.
Wimanella shelbyensis Walcott [1908d, p. 100].........-.-.-.-----.--.--.- Wimanella shelbyensis.
Wimanella simplex Walcott [1908d, p. 101].-...-.......-...-----.---.---- Wimanella simplex.
wimani [Obolus (Westonia)], Walcott [1905a, p. 337].........----....--..-.Obolus (Westonia) wimani.
wimani [Orthis (Plectorthis)], Moberg and Segerberg [1906, p. 70]. Ber aapuaels EKoorthis wimani.
Walcott [1905a, p. 272].......----------.---- Do.
winfieldensis [Orthis (Plectorthis) remnicha], Walcott [1905a, p. 270]..-..- Eoorthis remnicha winfieldensis.
wingi [Protorthis], Walcott [1905a, p. 286].....-- Aso aoc Or Te eeene ete neas Protorthis wingi.
winona [Lingula], Hall [U863, p. 126)..........-....--.------------------= Lingulella winona.
HLA TIGHU SO compel cea ee et Re eke umm cers UR Do.
Shane lasrorn [MENG Ts OEllboscacascasusseceeaucos coaccadce Do.
winona [Lingulella], Schuchert [1897, p. 258].........-...-..--...-.------ Do.
winona convexus [Obolus (Lingulella)], Walcott rae p. ee Bi eA ea! Lingulella winona convexa.
witrialpensis [Obolella], Etheridge [1905, p. 248]-- REE .----------Obolella wirrialpensis.
wirrialpensis calceoloides [Obolella], Etheridge [1905, 7 Dp. . 249]. See See els Do.
wirthi [Lingula], Barrande [1868a, p. 101]......--....---...--.------------ Lingulella wirthi.
iBarrandells68 br paGgllsesassseeee cere nee ee eee reer Do.
woodworthi [Acrothele], Walcott [1908d, p. 88].....--..-.-........--..---.Acrothele woodworthi.
wortheni [Obolus], Walcott [1908d, pp. 63-64].....-...--..--..--.-------- Obolus wortheni.
wynnei [Neobolus], Waagen [1885a, pp. 759-761].........---.---..--.---- Neobolus warthi.
Waagen [1891, Pl. II, figs. 10 and 11]................. Do.
Wynnia Walcott [190Se, Pl. XI, and pp. 142 and 148] ................--.- Wynnia.

62667°—vo1 51, pr 1—12——7

97

98 CAMBRIAN BRACHIOPODA.

Lo
Present reference.
yorkensis [Acrothele], Walcott [1908d, pp. 88-89]........-.--.------------ Acrothele yorkensis.
orkia Walcott! [LS 9/7 gpa 7A eee etapa ete = acetate aera ene ee Yorkia.
Walcott [1908e, Pl. XI, and pp. 142 and 146] ....-.....-.-..--.--- Do.

orkiamarquieliWalcottitewleeesseee eee eeeeeece cee. are eee eee Yorkia miqueli.
Yorkia? orientalis Walcott [1906, pp. 569-570].-...-.....-.----.---------- Yorkia? orientalis.
sYorkiaiwanneriWealcout SS ib eno silo) saseeeeseese see eee eeeee reese ee Yorkia wanneri.
Yorkia? washingtonensis Walcott [1897b, pp. 715-716].........--.---.---- Yorkia? washingtonensis.

Z.
zeno [Hoorthis], Walcott [1908d, p. 106].........---......-.--.-..--.------ Koorthis zeno.
zenobia [Micromitra], Walcott [new].......-...-....---.------------------ Micromitra zenobia.
zetus [Obolus (Lingulella)], Walcott [1898b, p. 419]..-........--.--..------ Obolus zetus.
Zeus) [emer ella) awa) co. uhs |e Wy See ee eee ee Lingulella zeus.
zoppi [Obolus?], Walcott [1901, pp. 684-685]........--....-....-..------ -Obolus? zoppi.

GEOLOGIC DATA.
GENERAL GEOGRAPHIC AND STRATIGRAPHIC DISTRIBUTION.

The distribution of the Brachiopoda, both Cambrian and Ordovician, is set forth in the four
tables following. The first (pp. 98-109) gives the general geographic and stratigraphic distri-
bution of the various Cambrian and Ordovician species, arranged zoologically; the second
(pp. 110-112) gives a summary of the Cambrian Brachiopoda by genera and by families; the
third (p. 113): a summary of the Ordovician Brachiopoda by genera and by families; and the,
fourth (p. 113) a general summary by families of all the Brachiopoda described in this paper,
whether Cambrian or Ordovician.

The question of the systemic reference of some of the formations (e. g., whether the
Orthoceras limestone and the Ceratopyge limestone should be placed in the Ordovician or the
passage beds between the Upper Cambrian and Ordovician, or whether the Ceratopyge slate,
the Bryograptus slate, and the Dictyograptus slate should be referred to the Upper Cambrian or
the Ordovician, etc.) does not appear to be a vital one in connection with this monograph.
Whenever possible, however, the localities included in these pages contain the names of the
formations represented, and these should enable the student to refer the species to the desired
place in the geologic column.

DISTRIBUTION BY SPECIES.

The following table gives the general geographic and stratigraphic distribution of the
Cambrian and Ordovician Brachiopoda taken up in this monograph:

General geographic and stratigraphic distribution of the Cambrian and Ordovician Brachiopoda.

Stratigraphic position.

Reeur-| Dis-
: Trent tinet
Name. No. | Page. Illustration. Cambrian: Dell Ge ae See General geographic position.
sage |doyvi-| varie- | varie-
Low-| Mid-| Up- |beds.| cian. | ties. ties.
er. | dle. | per.
ATREMATA.

Kio Yotece bees sees als ee eee ees tee Vermont and Pennsylvania.

Rustella edsoni-......-
J XK |leesec|booess|fe snecellcesscl|:sesser4|osscnne< New Brunswick.

PAM S Soe ssosseoe

Total species... ..

Mickwitzia formosa. - -. Sweden and Finland.

monilifera . ..-| Sweden, Finland, andRussia.
occidens. . . .--| California and Nevada.
pretiosa ..-. 2 .| Sweden.
? sp. undt......... Sardinia.

ARN SILOS ssee|seciaccilosccmece||soseasssoseeonsqooseobee 3 Cia Reaeee bepcue| eaese 1 5

a Type locality in italic.
b The exact stratigraphic position of this species is not definitely known.

GENERAL GEOGRAPHIC AND STRATIGRAPHIC DISTRIBUTION.

99

General geographic and stratigraphic distribution of the Cambrian and Ordovician Brachiopoda—Continued.

Stratigraphic position.

Recur-| Dis-
i rent tinet
Name. No. | Page. Illustration. Cambrian. Paes Ox: Se ee General geographic position.
sage | doyi-| Varie- | varie-
Low-| Mic-| Up- |beds.|cian.| ties. | ties.
er. || dle. | per:
ATREMATA—Cont’d.
Micromitra alabamaen-| 1 BBY EAGT ee Seseccaaacoeacltosede > doa ee aSaallseooes| |ooabeos lbeonosos Alabama and Tennessee.
sis.
aydenit=2-2--.---- 2 337 Idaho.
AISUIS sep 3 338 Quebec. ‘ ’
Mmealeign ees eaece ee 4 339 Montana, Wyoming, and Ari-
zona.
DUM. sosscasseass 5 339 H eweret, Bornholm, and Eng-
and.
COLCA Mas eiscecce 6 S¥0) |) Iie. Ol on coscaoccmoee S60) NSE BE Meese Scena Baesce scheddea ceases Scotland.
SCHIP tilisseeeeee eee 7 GV) | IPE INN 6 Snoemacooaesece|booe ae x Se) lecaecallceecoclooncodcdllogsacoce Montana, Wyoming, Utah, and
Nevada.
sculptilis endlichi..| 7a YE Cee See aa seddsus |oseoadl| paease Rfid Seoeea emcee lsaacber ocanoscs Nevada. ’
ZENO eee. s-ee seen 8 342 2 -| British Columbia.
Sprinter 9 343 Wyoming.
Total species... 7 6) baserclseaaue 3 9
NaN WACOM oo.cllacesne||boseueee|leseescoonsesssoosccoseecllecsase||eoecos IW agoosa Hosoeelancecdos 1 <
Micromitra (Paterina):
ella cee: ROE RE 1 SYM | TP so ccoccscssoocoed ban eeeces BeeeEH asters acecoc) Scorned jpoaacces Quebec, Newfoundland, Labra-
dor, Massachusetts, Vermont,
and Pennsylvania.
crenistria........-.- 2 345 MU on aoonsdeceesaoslaoetas x S40 Wesson sseecallocnocondiacosene Arizona, Nevada, Utah, and
‘Tennessee.
etheridgei-........-. 3 346 JOO prescacsqpaboas admis CE ESE somesd necore|soacocad bescocss South Australia.
labradorica.......-. 4 347 les ebaanmesses aed 36 Woscodd las seine|sesesc|ssoecs|ooscoondleczes=sq Newfoundland, Labrador, New
Brunswick, Quebec, New
York, Nevada, British Colum-
bia, and England.
labradorica orien- 4a 348 NO erica ccceacesaee jbcoaea Vi 1She60elsenacelboaces| pocacted |bocsopsd Shantung, China.
talis.
labradorica swan- 4b 348 WW sooo Aocasconesdd Vv We llaceood|eoesed[sssendlocaocose|[oncescss Vermont.
tonensis.
labradorica utah- Utah.
ensis.
labradorica var... .- Nevada.
Torani aes Quebec.
TEN) ts saaceoneS Alabama,
phillipsi--- England.
prospectensis. Nevada. : :
Stissingensis.-.-..-. New York, Missouri (?), and
British Columbia (?).
stissingensis ora... British Columbia.
stuarti Utah.
superba Arizona, Utah, and Montana.
undosa, Sweden.
wapta.. British Columbia and Alberta.

Total species
Total varieties. .--

Micromitra (Iphidella):
NOWISCE ee eases ee
nyssa

pannula._.._..-...-

pannula maladensis
pannula ophirensis -

Total species
Total varieties... .

Volborthiarecurva

Helmersenia ladogensis.

Curticia elegantula

Obolus acadicus....-...
? advenus ---
anceps
? ancillus
apollinis
apollinisingricus. ..

wre

apollinis maximus. .
apollinis quenstedti

369

380
380
380
381

381

384
384
384

{

2 3 bey seer eae ee 2 4
A DMB NLS 2A oes o7D0 2 aaa ee ee eee 2
| aed Pee oceeelo Saal meets ns aden
ed Eee eo a rer ee a
pec aos 66k > ae Sead Soeace aces aked econ sces

a The exact stratigraphic position of this species is not defin tely known.

Alabama.

Alberta.

Montana.

Sweden, Norway, Bornholm, and
Newfoundland.

British Columbia, Montana,
Idaho, Utah, Nevada, Ari-
zona, Georgia, Tennessee, New
York, and Cape Breton.

Idaho and Newfoundland.

Utah, Idaho, British Columbia,
and Shantung, China (?).

Minnesota.

Cape Breton.

-| Bohemia.
-| Nevada.

Bohemia.
Russia, Finland, East and West
Prussia, Sweden, and Poland.
Russia.
Do.
Do.

100

CAMBRIAN BRACHIOPODA.

General geographic and stratigraphic distribution of the Cambrian and Ordovician Brachiopoda—Continued.

Name.

Illustration.

Page.

ATREMATA—Cont’d.

Obolus—Continued.

? bavaricus .....-.-
belli eee ee

(QW. 5-s555s5o5sec)

eichwaldi.
elegans. .-
feistmante
fragilis...

ismene...-.

lamborni minimus.
loperi.._.--.-------
meconnelli-.....--.

meconnelli deci-
piens. 4
mcconnelli pelias.- - .

WIRD 55555505500

matinalis?........-
Iembranaceus....-
meneghinii

mickwitzi-.

namouna. -
nundina---
obscurus. .-
? palliatus. .
pandemia-. ee
panderi............

TNE SS Nees secesee

schmalenseei.....--
schmidti-..........

septalis....
shansiensis.

Simi phieeee eee

tetonensis leda..-.-
tetonensisninus. ..-
?torrentis...... ey
triangularis....
volborthi....
willisi. ..--. 22-2222

Total species... ..-
Total varieties. -. .

Stratigraphic posit on.
Cambrian.
Pas- | Or-
sage | dovi-
Low-| Mid- | Up- | beds. | cian.
er. | dle. | per.

Recur-
rent
species
and
varie-
ties.

Dis-
tinct
species
and
varie-
ties.

General geographic position.

Bavaria.

-| Quebec.

Shantung, China.

-| Bohemia.
-| Newfoundland.

Montana, Utah, Idaho,
Nevada.
Minnesota.

and

.| Russia.

Do.

__.| Bohemia.
..-| Newfoundland.
.| Sweden.

.| Missouri.
.| Missouri, Tennessee, Virginia,

and Georgia.
Tennessee.

.| Colorado.

British Columbia, Alberta, Mon-
tana, Utah, Nevada, and Cali-
fornia.

Nevada and California.

Montana, Utah, and Nevada.

Nevada, Colorado, and Ver-
mont (?).
Montana, Wyoming, Idaho,

Utah, Colorado, Texas, Okla-
homa,. Minnesota,b Wiscon-
sin,> Virginia, Missouri (?),-
and Vermont (?).

Shantung, China.

British Columbia.

Sardinia.

Wisconsin.

_| Shantung, China.

Bavaria.
Bohemia.

_| Newfoundland.

Wisconsin and Minnesota.
Nevada and Texas.
Shantung and Shansi, China.
Bavaria.

.| Tennessee.

Russia.

..-| British Columbia and Alberta.

a The exact stratigraphic position of this species is not definitely known.

b See footnote on p. 401.

Wisconsin.

New York and Vermont (?).

New Brunswick and Cape Breton.

Wisconsin and Minnesota.

Bohemia. :

Montana, Utah, Nevada, Wyo-
ming, and Georgia.

Sweden and Denmark.

Russia.

Cape Breton.

British Columbia.

Shansi and Shensi, China.

Wyoming, New, Mexico, Mis-
souri ‘Tennessee, Alabama,
and Texas.

Alabama. é

Montana, Wyoming, Arizona,
and Utah.

Utah.

Idaho, Oklahoma, and Texas.

Cape Breton.

Russia and Sweden.

. Russia.

Alabama, Georgia, and Ten-
nessee.

Arizona.

Argentina.
China.
Sweden.

GENERAL GEOGRAPHIC AND STRATIGRAPHIC DISTRIBUTION.

101

General geographic and stratigraphic distribution of the Cambrian and Ordovician Brachiopoda—Continued.

le
Name. No. | Page. Illustration.
ATREMATA—Cont’d.
Obolus (Bréggeria):
salteris- 222 ---\------ 1 424 | Pl. XIII, XV.......--
Obolus (Palzeobolus):
bretonensis.....---- 1 426 OOM ooecosenas4
bretonensis lens-..-| la AZT eerie ae seater ce eee
Motalispecieszeras eters | sess sces |seules sce oo ee nese cone
Notalivariebieseas eee g| tec metsas |e ecicic Semen ces seine ee
Obolus (Fordinia):
bellulus -.--..- 1 428
gilberti--.- -||. 2 429
perfectus..-.-.-..-- 3 429
Motalispecies seperate | tac cine cleans cee sense see melee
Obolus (Lingulobolus):
fafinis = easeh Ss ces 1 ZB |) 1, IOVS Se sccecseccoc
SpISSUSseee eee heen 2 432 XVI, XLII ...--.-
_ Total species....-|.....-|......--|----------------++--++--
Obolus (Mickwitzella):
Siluricus........---- 1 A345 PIONS = mee eeisseeicsae
Obolus (Acritis):
antiquissimus.....- 1 437 DOU D OViecaucaene
?rugatus..........- 2 441 eXGTI ae eeeisce
EVEN SAGES 5 ssellaasseelooussade| >aoenoogecousesecososass
Obolus (Schmidtia):
acuminatus........ 1 442 | Pl. XIV
eelatus........ 2 444
erassus. - : a|3 446
obtusus...........-- 4 448
ANGIE GaTOESIs sooalsscsae|estosasallsooodsoeooosancccSqcpane
Obolus (Westonia):
flandensis.......--- 1 451 | Pl. XLVIII........-:-
PERO coesacecsesee 2 451 ZONAL ccsssoe55022
ibalticus ss seeeeeeee 3 453 LAW teed
blackwelderi....... 4 453 YOO aogenbies
bottnicus .......... 5 454 DOU ANNE ss adeaese
chuarensis..........| 6 454 M
dartoni......... 7 455 | Fig
GIE ve csssasecanecede 8 455 | Pl.
ella onaquiensis....| 8a
elongatus........ 9
escasoni.....-.. 10
euglyphus..... 11
finlandensis..- 12
iphissssse eee 13
?lamellosus 14
notchensis 15
TOPCLSI = sae ei 16
stoneanus...-..-.-- 17
themisheeeess-s=sce 18
wasatchensis..-....- 19
WAT Speer eee = 20
Splundt: ae. 22-2. 21
Spend tye seee aa 22
Motalispeciesseres| Haeees seems seis se eiesisee eee
NOE WANES 5 loa sape||zocaaesaljosoncensdeosoconcab0cse0
Lingulella acutangula..| 1 AYN TE, BOAVM ocococcceases
agnostorum......-- 2 476 »: ©. 0 SE a eon nsane
ampla....-..-..--.- 3 477
GRP ceonosaeuaers 4 478
atava....2.-.--- 5 479
atavainsule -. 5a 480
@Upas Norco et eeee st & 480

Stratigraphic position.

General geographic position.

Recur-} Dis-

K rent | tinct

Cambrian. species | species
Pas-| Or- | and and

sage | dovi-| varie- | varie-

Low-| Mid-| Up- | beds.}cian.| ties. | ties.
er. | dle. | per.

eee | ees x eS Ll boosen scanaees| soaacece

Sobsee fen | Rebec| eben se eacen ssacdass Hacaooss

see eee Vv Shéer ceased pon cedlscootsed lbaoes6s
sees IN de Sog lsncasellonansalbcssaaue il
saneas Wy |bessbellacceselisascecllecousoces 1

Eoones 2 Ie BRASRal aBeersal Mescenee 3

Ree AEs eae leet rael | Sere Sia eae ee a
Sepoce| teatael Based beeeee SC Wa ees) eG ae
ee esl Baeeeie|| see sa| ease DANN laseaees 2

Se cebe| Ness eran! Seo Eee (lee nal noel
deeded) baeietel Besaas Si eta | Secon |e cea
neces Se Saco Dread ee Ria eee eee |e
anes aa || See beaten Pea Pe oe fee 2

SeSdes Asan Cn ee aol oes teusere 4

seaeee <0) es ol ice. Saal McBeal Eenore daca ed
ae al eee SENS Bs al. att | etree lee
eee S| eee Pt Sl a
Beaeee Sil) IS ae EES e aaa eaege| [a Picea eames}
Re aoe SoA aaa ae aie ie RC ars

x Massachusetts,

a The exact stratigraphic position of this species is not definitely known.
b This species occurs in passage beds between the Middle and Upper Cambrian, but is entered as Middle Cambrian in the tables.

Norway, Sweden, England, and
Cape Breton.

Cape Breton.
Do.

Nevada and Utah (?).
Utah.
Do.

Newfoundland and Massachu-
Soe
0.

Russia and Poland.

Russia and Germany.
Nevada.

Russia.
Russia and Sweden.
Russia.
Russia and Sweden.

Sweden and Finland (North
Baltic region).

Wisconsin and Minnesota. |

Sweden and Finland (North
Baltic region).

Shantung, China.

Sweden and Finland (?) (North
Baltic region).

Arizona.

Wyoming.

British Columbia, Montana,
Idaho, Wyoming, Utah, Colo-
rado, Nevada, Tennessee, and

Do.

Cape Breton.

Arizona.

Finland.

Nevada and Utah.

Bohemia.

Utah.

Rhode Island,
and Newfoundland.

Wisconsin, New Jersey,
New Mexico.

Arizona.

Utah and Idaho.

Sweden and Finland.
Shantung, China.
Nevada.

and

Missouri, Texas, Arizona, New
Mexico (?), and Nevada (?).
Sweden. ‘
Minnesota, _ Wisconsin,
South Dakota (?).
Utah and Nevada.
Cape Breton.
Do

and

Tennessee.

CAMBRIAN BRACHIOPODA.

General geographic and stratigraphic distribution of the Cambrian and Ordovician Brachiopoda—Continued.

Stratigraphic position.
Recur-| Dis- °
é F rent | tinct
mbrian. species P
Name. Page. ‘pean are || Gre vd | and | General geographic position.
sage | dovi- varie- varie-
Low-| Mid-] Up- | beds.| cian. | ties. ties.
dle. | per.
ATREMATA—Cont’d.
Lingulella—Continued.
ella Soe oss eee 481 | Pl. XIX, XXXVI.... Newfoundland and Rhodelsland.
bellula:-....-.-.--. 482 XIX. Newfoundland.
billingsiana--.-...-- 483 Do.

bornemanni...-....- 483, Sardinia.

[DbUISloSsencscceaccs 484 Alabama.

EINE OS ae nase me 484 Cape Breton.

cedens Sane sae eee 485 Bavaria.

Clark ere 5-6 ae 485 Nevada. i

COMI CIaa eee eee 486 Cape Breton.

concinna 486 -| Cape Breton and Sweden (?).

euneola. : 488 South Dakota.

damesi=ee ease neers 489 -| Shantung, China.

davidsoni...-....-- 489 Bohemia.

Gaivisineeeeeeee senor 489 North Wales, South Wales,
England, Cape Breton, Ar-
gentina, and China.

delgadoi-.......-... CKa ls Wa Wt SG DCA Rae ce cio |e See ld odado SBonE | Saeed] Mdemnd |abcae oe eeosco ac Portugal.

desiderata......-..- OD) |\. = SONG ee She 5 RRS LN SUN Kl Seeceas Ail cece |e aes Colorado, Wyoming, Montana,
Idaho, Utah, Nevada, Ala-
bama, Georgia, Tennessee,
Missouri, South Dakota, and
British Columbia.

dubia ee sae cee 494 Nevada.

GUGTES SS see eens sae 495 Quebec.

ferruginea.........- 496 Wales, Sweden, Denmark, Nor-
way, Newfoundland, Nova
Scotia, New. Brunswick, and
Argentina.

ef. ferruginea..-.--. 500 Bohemia.

flumenis........-.. 500 Cape Breton.

franklinensis.._--.- 501 Vermont.

HuUCHSi Ass Bey se 502 .-| India.

grandis 502 -| New Brunswick.

granvillensis 3 504 .-| New York and Vermont.

Inayesiisiaaeee sees 505 -| Alabama.

i 505 Spain.
506 Tonigng, Wyoming, Idaho, and
tah
507 Bavaria.
507 Tennessee and Georgia.
508 Bohemia.
508 Newfoundland.
508 Quebec.
509 Do.
509 Utah, Nevada, Idaho, and Brit-
ish Columbia.
511 India.
512 New Brunswick.
512 New Brunswick and Cape Bre-
ton.
512 Cape Breton.
513 Georgia.
514 Norway, Sweden, Wales, Nova
Scotia, and New Brunswick.
lineolata-..-..-.:<- 515 Arizona.

linnarssoni 516 Sweden.

manticula... ne 517 Nevada, Utah, and Idaho (?).

martinensis........ 518 New Brunswick.

CTO eee asec 519 New Brunswick and Cape Bre-
ton.

MOS Q/sa= see oe 520 Minnesota, Wisconsin, and Iowa.

mosia Osceola... -..- 521 Wisconsin.

WENO) oo seneoceas= 521 Alabama.

MathOrstioseeene ese 521 Sweden.

nicholsonj..-_...__- 522 England.

OLA Te ees ss eee ees 522 Gurion and Missouri (?).

OWeDoe ale ye a) 523 Wisconsin and Minnesota.

perattenuata.....-. 523 South Dakota, Texas, and Ari-
zona.

[Hea oy sosssesds 525 Minnesota and Wisconsin.

pogonipensis...-... 525 Nevada, Utah(?), and Arizona(?).

LIMA Re ee 526 New York.

?primeva... 527 South Wales.

punctata, 528 Nevada.

quadrilateralis..... 528 Alabama and Georgia.

radwlasesseee se ae 529 New Brunswick and Cape Bre-
ton.

randomensis 530 ..| Newfoundland.

rotunda. 530 .| Cape Breton.

schucherti. 530 .--| New York.

siemiradzk 531 -| Poland.

signata, 532 Bavaria.

a The exact stratigraphic position of this species is not definitely known.

ee

——

=:

GENERAL GEOGRAPHIC AND STRATIGRAPHIC DISTRIBUTION.

103

General geographic and stratigraphic distribution of the Cambrian and Ordovician Brachiopoda—Continued.

Stratigraphic position.

Recur-| Dis-
Rete rent | tinct
ambrian. spec i A
Name. No. | Page. Tilustration. Pas- || Or- Cae ceed General geographic position.
sage | doyi-| varie- | varie-
Low-| Mid-| Up- | beds.| cian. | ties. ties.
er. | dle. | per.

ATREMATA—Cont’d.
Lingulella—Continued.

Geis 5 sGeensoce] 71 5325| PEL NeXT a nee ec ee es | saeene x 5 $l Reese eeacacl pecaeosa HosSseor Minnesota, Wisconsin, Tennes-
see, Alabama, Missouri, Okla-
homa, South Dakota, Colo-
rado, Utah (?), Georgia, and
Nevada.

? simplex 72 .-| Bohemia.

tarpa... 73 .-| Tennessee.

texana 74 -| Missouri and Tezas.

torrent 75 Cape Breton.

triparilis 76 Do.

tumida 77 Do.

tipis-aeee 78 .-| Texas.

wanniecki 79 .-| India.

welleri..- 80 -| New Jersey.

winona 81 .| Jowa, Minnesota,and Wisconsin,

winona conyexa 8la Wisconsin and Arizona.

Wirthi..2---.-.2- 82 .| Bavaria.

ZEUS eee eee 83 -| Scotland.

sp. undt. a...- -| 84 .| Sweden.

sp: undt. b......-.-- 85 Pennsylvania. :

ANI SOE. oslo s5e05|beaoones| beaaesqacaseccecsaancase 5 46 30 6 13 20 85
Aol yaratantes S414 85338 bebocsed MaSesesoseasseeescerosee Seace 1 Bian ee eisr aaa eee eee 4
aaa (Leptembo-
on):
lingulzeformis ....-- il B23} || JL SON. oaascesesges|soscedfossee- | OX 28 ilboduee aero peniseoecs=s Esthonia, Russia.
Lingulella (Lingulepis): A
acuminata........- 1 545 XXXIV, 2G, caso x oe i bseaas Gall PAPERS necencce Ontario, Quebec, New York, Vir-
XLI, XLU. ginia, Alabama, Tennessee,
Oklahoma, Texas, Nevada,
Utah, Colorado, Wyoming,
South Dakota, Minnesota, Ver-
mont, Wisconsin, and Michi-
an.

acuminata meeki...| la 550 0.4 Fee nae eee Eases ian Rested baoseel ssesee| beecoona accross | Wyoming and Montana.

acuminata sequens-| 1b New York.

LOS Sey om ae ees 2. Shantung, China.

exigua.- 3 Cape Breton.

gregwa 4 Do.

gregwa robusta....- 4a Do.

Jonginervis---..---- 5 Do.

pumila ME au a HE. 6 Do.

? pygmea ..-...--- 7 England.

TOMER seen see 8 Cape Breton.

rowei... 9 California.

Spatulayee se 10 Arizona.

? squamosa....-_-- il England.

Stannieees eeeeeaae 12 .| New Brunswick.

sp. undp. = 5. -5-- 13 Shansi, China.

Total species. --. 9 1 3 13
2 1 sdesiés 3

Total varieties. . -
Delgadella lusitanica. --

Elkania ambigua.......
desiderata..........

Bicia gemma.......-...
whiteavesi........-

Total species. --.-

Dicellomus appalachia -

prolificus........---
sp. undt-...

Total species

@ Th, PEO
Fig. 47

eat WAU L S ee enone

Soasselecosce beer oc laeqeac 6 Ai lsoeesarc lsoasmSee
ages | Tl ee Fala ead nie
Vere pret espa ces Lota NE eT, age ak
Seka eee [Es su eee ee | ES
sil eee ae ed ee EU he Weer ee reek
Ber || Gale ee a | eR 2
Bees > Ge eal Bemioee see bac] bcereaae Bosos ccs

Vie coal scm | Sais bliss [operas
Sodnen > Gal Sec aed ceed barre ssoaaec
eco >. Sal Peoceiad| peroca soaada Baeeronc!
iia Rall Olbceala shee 7

Portugal.

Nevada.
Quebec.
Do.

Thdia.

Quebec, Labrador,
York.
New York.

and New

Tennessee, Alabama, and Vir-
ginia.

Montana, Wyoming, South Da-
kota, and Missouri.

Shantung and Shensi, China.

Montana, South Dakota, and
Wisconsin.
ontana, Utah, Arizona, South
Dakota, Oklahoma, Tennes-
see, Wisconsin, Missouri, and
Minnesota.

Utah.

Sweden.

104

CAMBRIAN BRACHIOPODA.

General geographic and stratigraphic distribution of the Cambrian and Ordovician Brachiopoda—Continued.

. Stratigraphic position.

i

General geographic position.

(Labrador, Quebec, Vermont,
Nevada, British Columbia,
and Siberia.

Newfoundland.

-| South Australia.

Nevada and California.
Sardinia.
Virginia.

Montana.

Shantung and Shensi, China.

ee ae Massachusetts,
and Georgia.

Labrador, Newfoundland, and
New York.

Labrador, Quebec,
New York, Pennsylvania (?),
Goorens (?), and Massachu-
se’

Quebec.

England.

Sweden.

Maryland, New York, Pennsyl-
vania, Virginia, and West Vir-
ginia.

Sweden and Norway.

Vermont,

-| California and Alberta.
-| South Australia.

Portugal.

Sweden aud Norway.

Spain.
New Brunswick, Quebec, Ver-
mont,Labrador,and New York.

.| India.

_..| New Brunswick.

Recur-| Dis-
rent | tinct
Name. No. | Page. Illustration. Canibrian: Base | (ORS | cea eee
sage | dovi-| varie- | varie-
Low-| Mid-| Up- | beds.|cian.| ties. ties.
er. | dle. | per.
ATREMATA—Cont’d.
a 6 PIV sie eons sans

Kutorgina cingulata....) 1 580 {Fries 3, 8, and 50...... \ XK |[ocoeeclloceocd|lenssoc|[ocaccnllacceesad|ocsocass
granulata.....-:-.- 2
peculiaris. 3
perugata.......-..- 4
Sardiniaensis..-..-- 5
oh WMNCincossoccceos|

MotalispecieS eae === ear =| aaa a [eee ae ee 4 2 \locasec|essase|sesess|[bosnes= | 6

Schuchertina cambria..} 1 EG) || WG Wiles csconosbeanees|basose Gian SASAes peed Gasedellonqaesedlsepeccdo

NEOTREMATA.

CLOG ES NE ecossc| tl jf) BERN) WAVo ese secseceossad| 2S llesccod||esecad|fescacd)|scoasd|paceosndloocooscs
atlantica......---.- 4 |) EAS) |r es PESTO OARS REE REOS FO |lotecoslescsog|lesacesloosenel[eociesace|lesceseos
chromatica........- Bf Bg BE WIN, coco occcosd| OX |ecetor|bessina|saasbeliscssodftecscaca|oossece
Crassa=. 2h s eee Ch GEA aber to Mt eS Mesos boecconllecsccd|[socsels|lecsoccuc|[ssoscose
erassa elongata... .- Gey || BAS) |] TPL WUVonesecsceesssoce|| WF llescoce|[soecec||sececo|[eossselooseceseflosessoce
groomi......-...-.- 5 =
? lindstr6mi-....... 6 3
WOT) = Bonanooncne 7 | BB | WNW owe ceccecenoee||] O46 |[esecodleooccqlecoceellescons|fosccossfoascesss
mobergi.-.....-..-- 8
vermilionensis.....- 9
wirrialpensis--..-.-- 10
Soe Wii ste osceen 11

Motalispeciesemeca| sess cee el eee case eee cet 1b eoee| Selec na ocaeHe scgeud jslsca sic 11
Totalvarieties:--2)------|------- |< -- 2 Wo llscoeed|[osceos[sececel[eonzselaccoscoe 1

Obolella (Glyptias) :
favosa .....-..--.--

Boetsfordia? barrandei..

Crelata ...-22- 2222.
granulata.........-
pulchra............

Total species....-

Schizopholis rugosa... .
Quebecia circe.........-

Yorkia? miqueli .......
? orientalis..--.....

? washingtonensis. .

Total species

Dearbornia clarki

Trematobolus excelsis. -
insignis
kempanum.. .
pristinus

Total species

Schizambon? esthonia..

Total species

Siphonotreta? dubia...
unguiculata

611 LXXXILI

612 LXXXII

612 LXXXIL

613 POO ibys ses sope
614) (Pl. UXKKT. |. -
617 WROOMM se dosed
617 LXXXIV.._..

oe) CXXRU.

621 { DEON o.

622 | Pl. UXXXIV.........
623 LX XXIV...

623 TPO Nac ceecon,
624 TWO TVacccecsee
625 | Pl. LXXXI..........
626 TERR Aetna
627 LR RERT ee eee

2 lesoteellozescallooseccllecocec||-cosecae|[orosescs
2 1G Msseose 1 | eee | eee 4
zocose Dili se cesal Poceoellaeegse lcoossecd lseaoods

Oh |lsessen

sree x

oe x

bode Doel bsavec Soeane leesocelticaacses|eneaedos
1 8 |pccenolloocetcliccocesessooens 4

eater gs hae SC lucene |e Ih noe ead See

eeeA | Syacee Biol eee he 1 4
SCAT. Sh SA Ee CORTE ie ea Le

ieee oad EAN SCA Vw aa | pte ual VE aa

Pree cea eetel re Sala aac ee | Be as
1 Seas sects 2 2 2 3

| India.

Quebec and Labrador.

France.

Shansi, China.

Quebec (?), Pennsylvania, and
California (?).

New York.

Montana.

California.
New Brunswick.
Do.

Do.

Russia.

Colorado.

Cape Breton and New Bruns-
wick.

Nevada and Utah.

Nevada.
Russia and East and West
Prussia.

Do.

a The exact stratigraphic position of this species is not definitely known.

GENERAL GEOGRAPHIC AND STRATIGRAPHIC DISTRIBUTION.

105

General geographic and stratigraphic distribution of the Cambrian and Ordovician Brachiopoda—Continued.

Name. No. | Page. Illustration.
NEOTREMATA—
Continued.
Keyserlingia buchi-..... 1 628 | Pl. LDXXXI..........
Acrothele artemis il Gee Ge eS ceatbocsasded
Ehitipopesos 2 634 | Pl. LXI, LXII
avia puteis. 2a GE |Sasenoasscsesee
bellapunctata. - 3 636 | Pl. LVII..-
bellula.....-- 4 637 LVIII. .
bergeroni. - 5 638 LVIII..
bohemica. - -- 6 639 LVII...--
borgholmensis.....| 7 639 LXIII.
ceratopygarum. -..- 8 640 LXIII.-
colleni........----- 9 640 Aime eee
eoriacea 10 642 | Pl. UVI.....-
decipiens -| 11 644
dichotoma - 12 644
gamagei-.....- 13 645
intermedia-......-.- 14 646
levisemsis.-.-...--.-- 15 646 IDO: OO aessooce
maculata. 16 647 LVIlI, LVIII.
inatthewi 17 LXI
matthewi eryx...-- 17a
matthewi lata... ..- 17b
matthewimulticos-} 17¢
tata.
? minuta 18
mitid ase seen. 19
panderi 20
pretiosa 21
TMA ee ose eee se 22
prima costata 22a
primeva 23
proles 24
quadrilineata . 25
TENE Ss ce aacopEeseee 26
Spurrites shee 27
subsidua.....-..-.- 28
subsidua hera...... 28a
subsidua levis -- 28b
(HUbVAS co ce Sedoe 29
villaboimensis. - - -. 30
woodworthi........ 31
yorkemsis.-...-..-. 32
sp. undt.a.,......-. 33
sp. undt. Moberg...| 34
AROMA TIES — co e|lsesens||soctosca bonceeconsescoasecsnosan
Motalisvarieties yess eee Se alee ceemacecieecseccce
Acrothele(Redlichella):
granulata .......... 1 P| TI NAc sees gocasescs
Discinolepis granulata..| 1 664 102; O:©.G IS neeaeee
Linnarssonella girtyi...| 1 666 { ey PRE Ee

Acrotreta argenta
attenuata

babel
baileyi

belti-....
bisecta.

?? cancellata
Caninatase- =) elses. 5

claytoni

(|| IG IDOL cece eeece
675 LXIV, LXXIX...
676 DPX ssn een
676 LXXVII

676 LXXVII

677 LXXVIII..

678 LXXVII

678 IED. CW Waeaapeearaae
679

679

680

680

681

10 21 3 2 2 4 34

1 (@§- |lessarcllosoaselacooss|ledessore 7
scocse XS |leaosee||soostellsacoaclisssegca|éaccdcan
sosece DS) Wooceac|lootsee| Seasac|boosssossoccionas
digs x M6 llacocecllesceodeos=enscllaeceosce

Stratigraphic position.
Recur-| Dis-
: rent tinct
Cameo. esl) Om yd | and | General geographic position.
sage | dovi-| Varie- | varie-
Low-| Mid-| Up- | beds.|cian.| ties. | ties.
er. | dle. | per.
Eoadse|boaces 26 losesqelleasasclfscococcs|iscopsacel! INDESE,

Idaho.
Cape Breton.
Do

Norway.
Alabama.
France.
Bohemia.

.| Sweden.

Norway and Sweden.

Montana.
Norway,
mark.
Pennsylvania.
Nevada.
Massachusetts.
Sweden, Denmark, and Eng-
land (?).
Quebec.
Wales.
Newfoundland and New Bruns-
Wick.
Shantung, China.
N one Brunswick.
0.

Neires Columbia, Alberta, and

Sweden, and Den-

Shantung, China.

New York.

Montana.

Quebec and New York.

Nee Brunswick and Cape Bre-

on.

New Brumswick and. Newfound-
land.

Spain.

Cape Breton.

Bohemia.

Shantung, China.

Nevada.

Utah, Idaho, and British Co-
lumbia.

Pennsylvania.
Quebec.
Sweden.

Sweden.

India.

ee South Dakota, Oklahoma,

Texas, Nevada, and Missouri.
Nevada.

Tennessee and Utah.
Utah.
Do.

Nevada.

Nevada, Utah, Wyoming, and
Montana.

Montana.

Bohemia.

New Brunswick.

Utah.

North Wales and England.

Caper Brace and New Bruns-
wick.

a This species also occurs in passage beds between the Middle and Upper Cambrian.

106

CAMBRIAN BRACHIOPODA.

General geographic and stratigraphic distribution of the Cambrian and Ordovician Brachiopoda—Continued.

Stratigraphic position.
Recur-| Dis-
rent tinet
jan. cies | species = a0)
Name. Tilustration. Cambrian =o are end | and | General geographic position.
sage | dovi-| Vatie- | varie-
Low-| Mid-| Up- | beds.|cian.| ties. | ties.
. | dle. | per.
NEOTREMATA—
Continued.
pcs aa oa Sweden.
convexa.-.......-.- -| Cape Breton.
curvata.. : .| Nevada and Oklahoma.
definita.. -| Nevada, Idaho, and Wyoming,

depressa... ..
eggegrundensis
emmonsi.

PTAC DS Sa tee Asa
idahoensis

idahoensis alta....-
idahoensis sulcata.-
ef. idahoensis....---
inchoans. -- 2y2
inflata....

marjumensis . a

microscopica.-.-.--

microscopica mis-
souriensis.

microscopica teton-
ensis.

Fern, - = 5 555cc

WHI) 5-52 seq0520

neboensis......--.-
nicholson

celandica.
ophirensis. -
ophirensis
dens.
ophirensis rugosa. - -
cf. ophirensis. .-..
Ovalis:-._-2

primeeya -- Gat
pyxidicula. 2... --

sabrinee ae
Sagittalis.--..---._-

sagittalis magna... -
Sagittalis taconica..

sagittalis transversal

ef. sagittalis -
schmalenseei
Seebachi....- eae
shantungensis. -..--

SIP 2S See
socialis.
spinosa.
subconica- -
ulvichi--__ ae
uplandica. .-..-.-..
uplandica limGensis
SDE eeeee eee

porcine.

Total species. ----
Total varieties. --

signata prim Sano

Total species... -.
Total varieties... .

IDO WAN osoece sed
IPO ede cee oes

TU SKEXV UTP
LXXUL Boa
LXXVIL.

“Pl. LXXIV.
TPXEXG TLE

IPO; ee sae se sos

Pl.
LXX
LXIX

IES ILO Nl ee ea a
LOT penaseasueb mas
Pl. LXXV, LXXVI

British Columbia.

Sweden and Finland,

New York.

Newfoundland.

Nets Brunswick and Cape Bre-
on.

New Brunswick.

Nevada, Utah, Idaho, Wyoming,
Montana, and South Dakota,

Nevada, Utah, and Montana.

Utah and Idaho.

Nevada.

.| Bavaria.

.| New Brunswick.

Alabama and Tennessee.

Shantung, China.

Utah.

-| Nevada, Texas, and Oldahoma.
Missouri.

Wyoming.

Beets Bohemia. |

Bae ae a Newfoundland and New Bruns-
wick.

Utah.

--| Scotland, Ireland, and England.

.| Wisconsin.

Sweden.

..| Shantung, China.
..| Sweden.
.| Nevada.

Nevada, Utah, Idaho, and Mon-
tana.

Tennessee.

.| England.

Sweden, Norway, Denmark,
Scotland, Ireland (?), Wales,
Newfoundland, New Bruns-
wick, and Quebec.

Becta New Brunswick.

Asa ts Net York and British Colum-

ia.

Newfoundland and New Bruns-
wick.

.| Utah.

Norway, Sweden, and Denmark,

.| Norway and Sweden.

Shansi, Shensi(?), and Shan-
tung, China.

Wisconsin.

-| Sweden and Denmark.

AP SOOE Sweden.

Idaho.
.| Cape Breton. )
0.

a The exact stratigraphic position of this species is not definitely known. H
v This species niko aan in the passage beds between the Middle and Upper Cambrian.

GENERAL GEOGRAPHIC AND STRATIGRAPHIC DISTRIBUTION.

107

General geographic and stratigraphic distribution of the Cambrian and Ordovician Brachiopoda—Continued.

Stratigraphic position.
Recur-| Dis-
2 rent tinct
Name. No. | Page. Illustration. Cambrian. mull oe Pd. | and | General geographic position.
sage | dovi- varie- varie-
Low-| Mid-| Up- | beds./cian.| ties. | ties.
er. | dle. | per.
NEOTREMATA—
Continued.
Discinopsis gulielmi-...) 1 (PD) FAI O OO a heedcllsansos o& |ecesaloosson| boone eaccaacd|seccunce New Brunswick.
?suleatus.-.--.--.. 2 721 1; ©. 0.4 0 Bee seeceer| scored pacese SN peters pecaed GeTasecn tepssces Shantung, China.
UNGHANLRTBIOES Ss Sa¢lcaadac aoaeober Soacarobecube cose SbEeosH teased 1 iV ll besaan Sscnacisasdcond 2
Orbiculoidea contraria..| 1 722, | Pl. UXoX XT... .. Bavaria.
Pileolus...........- 2 722 LXXXI.. -| North and South Wales.
VATIGTS! ose aielminle = == 3 723 LXXXI...... Bavaria.
Motalkspecleseeres | seme sceneries |sesece a aateee ae sae eee Dogs | eer ae PHA Becca Maesoree 3
Philhedra columbiana..} 1 (24. PV AXeXERT: . 35 5. astel| seis Kia hesock |shesac les aoa| PRE Set eens British Columbia.
PROTREMATA.
Nisusia alberta.......-. 1 British Columbia and Utah (?).
lcomptansssesee eee 2 South Australia.
Labrador, Quebec, Vermont,
festinata..........-. 3 New York, Pennsylvania, and
British Columbia:
festinatatransversa.| 3a Vermont.
Mara ssee es meses ee 4 Idaho.
? vaticina ..-......- 5 Spain.
Total species.-.-.|.-.-.-
Total varieties. ...|...-.-
Nisusia (Jamesella):
Ghat” cone coospoase Quebec.
argenta. Nevada.
erecta Do.
kanabensis. Arizona.
kuthani Bohemia.
lowi . .| British Columbia.
nautes Idaho, Utah (?), and British
Columbia (?).
mpellico= eee se ees - = Spain.
perpasta.-.-.-- ae Bohemia.
perpasta macra....- Do.
perpasta subquad- Do.

rata.
spencei.....-....-.-
utahensis.........--
o> DuaNGh ho nescseeses

Total species
Total varieties... .

helenae... 222 -225-2

levis
latourensis--.-.-..--
quacoensis .
wingi. -
sp. undt..

Total species....-

Protorthis (Loperia):
dugaldensis

Wimanella? anomala...

Total species

Billingsellsy appalachia.

exporrecta--.------

exporrecta rugosi-
costata.

INES concencnaed

Qa oRwror

WMA) TPL AOC spec ce

745 IDO ocecooe

746 LXXXVII...

T3 |) INE oe cocssass

747 | Plo LXXXVIT. --

WT | pL LXXXTX

748 (Rig. CU Meream en (na

750 | Pl. LXXXVIT........

(5) || 18 Bap eueeececconac
Pl LXE V. ...-

co {Rige: 5 and 66...

754

754

755.

756

Idaho and Utah.

Utah.
Labrador.

New Brunswick.
Do.

Sweden.

Wisconsin.

__.| New Brunswick.

Do

“|. Vermont.

Arizona.

Cape Breton and New Bruns-
wick.

Alabama.
‘Tennessee.

a The exact stratigraphic position of this species is not definitely known.

California.
Tennessee.
Alabama.

Montana and British Columbia.

Tennessee and Georgia (?).

California.

Montana, Wyoming, Idaho,
Utah, Texas, Missouri, Wis-
consin, Minnesota, British Co-
lumbia, and New Brunswick.

Vermont,

Sweden.

Do.

South Wales.

108

General geographic and stratigraphic distribution of the Cambrian and Ordovician Brachiopoda—Continued.

CAMBRIAN BRACHIOPODA.

Total species.....
Total varieties...

Otusia sandbergi.......
utahensis........--

Wynnia warthi........

Eoorthis agreste........

atava......-
bavarica....
christianiz -
Gatinisse sees

desmopleura _..__..

kichouensis -
linnarssoni. -
newberryi-

newtonensis.
pagoda...
papias.. Be
primordialis......_.
remmnicha..........-

remnicha sulcata...
remnicha texana. ..

remnicha winfield-
ensis.
saltemsis............
tatei.._.
thyone..
imate F
wichitaensis

Wwichitaensis levi-

786 {

791

791
792

792

a The exact stratigraphic position of this species is not definitely known.

Stratigraphic position.
Reeur-| Dis-
c rent | tinct
Name. No. | Page. Illustration. Caxabman: ecules eA | ana | General geographic position.
sage |dovi-| Varie- | varie-
Low-| Mid-| Up- | beds.|cian.| ties. | ties.
er. | dle. | per.
PROTREMATA—
Continued.
Billingsella—Cont’d. - \

i TH anibsGbnals Ran aaN 7 756 Wevada and California (?).
lindstrémi.. dll -@ 757 Sweden. | : i
major... 9 758 Wisconsin and Missouri (?).
marion... 10 758 British Columbia.
obscura... 11 758 .| Arizona.
orientalis... 24|| 2) 759 .| Vermont.
Plicatella........... 13 759 Montana and Wyoming.

umpellyi........-. 14 760 Shantung, China.
Sanne el} | 155 761 .| Cape Breton. a
richthofeni . 16 761 -| Shantung, China.
romingeri . 17 762. Bohemia.
salemensis --| 18 763 LXXXVII. -| Quebec and New York.
striata....- --| 19 764 LXXXVI -| Montana.
whitfieldi. 20 764 LXXXVI. Nevada.
Motalispecies! se2t|:2 <2 |= sueeses| sees eee reason eee seeees 5 12 OMe eee 4 20
Motaltvarietiest: 53 |{ Oe eee ie Ee Mere ene eee eens il lsceooalloccocalecosonlseacdes 1
Orusia eurekensis...... 1 765 .| Nevada.
lenticularis.........| 2 765 .| Norway, Sweden, Prussia, North
Wales, Newfoundland, Cape
Breton, New Brunswick, Ar
gentina, and Nevada.
lenticularis atry- 2a 769 PONT 00 Pee sanaea| sacuae| sane Vo [cece |oseis see sector el Geet New Brunswick.
poides.
lenticularis lynci- 2b 769 EXC WET es Soe ce eel: keel ees i | Heol MaROee Smactescel eeiseelae Do.
oides.

Minnesota and Montana,
Utah.
India.

Shantung, China.
New Brunswick.

.| Bavaria.
._| Norway and Sweden.
East Prussia, Norway, and

Sweden.
Colorado, Utah, Montana, Wyo-

mings New Mexico, British Co-

lumbia (?), and Pennsylvania.
Colorado and Wyoming.

Wisconsin.

.| Shantung, China.
.| New Brunswick.

Wyoming and Texas. "

.| Missouri, Oklahoma, and Texas.

New Brunswick.

_| Shantunq and Shansi, China.

Shansi, China.

.| Shantung and Liaotung, China.
.| Utah.

.| New Jersey.

.| Shantung, China.

.| Newfoundland.
.| Spain.
Wisconsin, Minnesota, Mon-
tana, Utah (?), Oklahoma, and
Wyoming.

Wisconsin and Minnesota.

Oklahoma, Montana, Teras, and
Missouri (?).

Wisconsin.

Argentina.

-| South Australia.
-| Utah.
-| Sweden.

Colorado, Oklahoma, Montana,
Texas, Missouri, and Wyo-
ming.

Oklahoma and Texas.

Sweden and Norway.

.| Utah.

Bohemia.

GENERAL GEOGRAPHIC AND STRATIGRAPHIC DISTRIBUTION.

109

General geographic and stratigraphic distribution of the Cambrian and Ordovician Brachiopoda—Continued.

Stratigraphic position.
Recur-| Dis-
2 rent | tinct
Name. No. | Page. Illustration. (CERISE, Pas-| Or- ee Saas General geographic position.
= sage | dovi-| varie- | varie-
Low-| Mid-| Up- | beds.}cian.| ties. | ties.
er. | dle. | per.
PROTREMATA—
, Continued.

Koorthis—Continued.

Total species. ----
Total varieties... -

Finkelnburgia finkeln-
burgi.

osceola corrugata. ..

Total species... .-
Total varieties...

Eostrophomena _ ele-

gantula.

Swantonia antiquata...
WEES Secdseasence

Total species. .---

Syntrophia alata.
barabuensis. -

campbelli. .
lateralis...........-

primordialis argia- -
rotundata 23
? unxia

Total species. ----
Total varieties. - .

Total species.....
Total varieties...

Clarkella montanensis. -

-_| Bohemia.

Shantung, China.

-| Shansi, China.

Shantung. China.

Wisconsin and Minnesota.

Wisconsin, Minnesota, and Iowa.
Wisconsin and Minnesota.

Oeland Island, Sweden.

Vermont.
Nevada.

Texas.

-| Wisconsin.

Quebec and Newfoundland.
Utah.
‘Tennessee.

Vermont.

Nevada, Utah, and Colorado.

Shantung, China.

Minnesota, Wisconsin, Okla-
homa, and Wyoming.

Minnesota.

Wyoming.

Utah.

Montana and Wyoming.
Vermont.

-| South Australia.
-| Utah.
-| Shantung, China.

Texas.
Do.

-| Vermont.

Montana.

a The exact stratigraphic position of this species is not definitely known.

110 CAMBRIAN BRACHIOPODA.
SUMMARY OF CAMBRIAN BRACHIOPODA.

The distribution of the Cambrian Brachiopoda is summed up in three tables. The first
(pp. 110-111) gives the general geographic and stratigraphic distribution of the genera; the
second (p. 112) gives the same information for the families; and the third (p. 112) is a summary
of the Cambrian Brachiopoda by genera and species.

Summary of Cambrian Brachiopoda by genera.

Cambrian. Recur-

Passage | rent spe- | Distinct | Distinct
beds. cies and | species. | varieties,

Lower. | Middle. | Upper. _ | varieties.
ATREMATA:
RUSTELLIDZ—
IRMIStEUANSPeCleSiyre lone sess eee eee ese sees ee ee onesies 7) Boa anaaacal ssancbenos|asccsnemas|Goncuseaed 2} eee
PATERINDE—
Mickwitzia, species. . OH ROpBaee an nee SSoees6 1 O} (eels rts aete
Micromitra, species 2 2 7 | bee sabe ores 3 Ql Soo
Niet GWICS aden BS ces Sen ems Fanec OSAP SAGER AEC BRaC ae anade Act eebal scadasosad faterecaste 1 Meese Ses cseeben sal Mansersses 1
(Paterina), species.............- 8 i 2 | eer 3 4S rcesee
Warleties S335 on Sea 3 2 ASN Soe 2115 eS a aera 1M i Seaetei cre 5
oe) species so i 2 oe 22 5 2 3 ils] Roeser 2 AA eee te eae
ATA CUIES cee eter eaten Re reer eee etree nore oO men re een E eeeteR Ieee PW Bae Aer USEC ee nem Man syecsae MERenAsead 2
IEelmersenia, {Species siz isso ns se cee ee cece ee ee cee ee ole | eae ee eee Naeem ence i ESS tee ey AC ae Bh hic eae Sek
if |.
Motalispecies ssc e 5 aos eee bees Sos le sci e ae ore eee 15 20 Uhi| Seer eee ag BE eee
Motalivarleties!2 jessaes foe ee socee else Ose etree eel 7) 6 ALA Sees NS ape ARs 8
CurticopDzA— |
@urticias speciese: = seescecce sect neice oes eaters coe a ee see ere |e oie meee | Cee eee 1 Ree eececs Sesedacbad i eeeeeretcs
OBOLIDA— l
@polus¥speclesseeseee-se cer sere tee eee ee ee
WemicinGa es ecseencsasoansessc

(Broggeria), species .......-...--
(Palzeobolus), species --.-.-.----
Varieties == ese emeee oasee scene
(Fordinia), species. -......-.-.--
(Mickwitzella), species. ...-...--
(Acritis),/speciest=- 222 2227.--2--22
(Schmidtia), species.
(Westonia), species
Varieties. . -
Lingulella, species.-........-...-----
Varieties. ._..-
(Leptembolon), sp:
(Lingulepis), species. .........----
Warietieseeem see eee nee Sfeoeae
Delgadella; Species =.= -222 22. L 2222 a8
INeobolus ispecies pases yee scene seeeee
IBICIaSDEGICS ae ee eee eee eee
Dicellomus, SPOCLES MoE he os bees Se a eames sae eae cece

Totalispecies ssa. -s-eepae ese ae eC ase ee cae eases 13 109 87 17 40 186 Ue ee
MOLALVATICUIES eat tes eee es See aa eles Bee react ol tana 2) /e Aen ame 6 10

KuroRGINDE—
ieutoreina, Speciese. ane eee ee cee ete b eee cee eee ee cee ae 4 7 AE oe erences Kapa Bet it Meese

SCHUCHERTINIDA—
Schuchenrtina,speciesh ance cwecs certs se eae se ee ponet ete| Reet i US Bere serace| Masisaeeror loease cates Lis | Sara ee

NEOTREMATA:

OBOLELLDA—
Obolella, species...--......---.------.---
Varieties... .- aN
(Gly pias), /speciesHais ae esac sans Ae eee
‘Botsfordigvispecies? 9 a5: kc PSsR ses Seen ene ere cake cee mn moa a
Schizopholiswspeciess-aeee errr ee see er eee eee ee ee eee eee aoe
Quebecla ispecies eee ee ee ee ae ee eR ee eae

Motalispecies Ssh ia. Lk Yel hee e ae fee ate = Nee eeae ce
Rotalwvanieties arses. ove see eee eee ee ee ee

a Two species pass up from the Lower to the Middle Cambrian, four from the Middle to the Upper Cambrian, and one from the Lower to

phe Upper Cambrian. One species is common to the Lower, Middle, and Upper Cambrian. One variety passes from the Lower to the Middle
‘ambrian.

b Fourteen species pass from the Middle to the Upper Cambrian and one continues into the passage beds. Four of these species pass up
from the Upper Cambrian to the Ordovician. ;

c One species is common to the Lower, Middle, and Upper Cambrian, and one species passes from the Middle to the Upper Cambrian. One
species passes from the Upper Cambrian to the Ordovician. (

@ Two species are common to the Middle and Upper Cambrian and pass up into the Ordovician; eleven species pass from the Middle to the
Upper Cambrian; two species pass from the Upper Cambrian to the passage beds; and two species pass from the Upper Cambrian to the Ordovician.

€ Two species are common to the Middle and Upper Cambrian and pass up into the Ordovician. :

f One species is common to the Middle and Upper Cambrian; two species pass from the Middle to the Upper Cambrian; and one species
passes from the Upper Cambrian to the Ordovician.

—.

GENERAL GEOGRAPHIC AND STRATIGRAPHIC DISTRIBUTION. 111

Summary of Cambrian Brachiopoda by genera—Continued.

Cambrian. Recur-
Passage | rent spe-| Distinct | Distinct
‘ beds. cies and | species. | varieties.
Lower. | Middle. | Upper. varieties.

NEOTREMATA—Continued.
SIPHONOTRETIDH—

Schizambon, species. - :
Siphonotreta, species. 3
Ie ySerlin gia, SPECleSs te cince = doc one eel cose cece ee cee ee neoeeaneee

Motalispecies = oe sla=ecic Sess ems ocie siete aol seen cease
Motel arictiesetss fog eM sce skian Hoes eee Runes

ACROTRETIDE—
PCO UCL OMSDECIES Bem ce nares ore oie neat Seiciatoe ate A etter ae ae ees
Warieties.........
(Redlichella), species.
Discinolepis, species. .- .
Linnarssonella, species.
Acrotreta, species... .---
Varieties.......
Acrothyra, species. .
Varieties... ...-.

Motalispecies ey sey sese recess Usa eek oe ME es st eee 13 64 31 9 17 TOO Ko seagace
MRO Pal ARIOLICS welts cen ee eee nce cee ecee Sees eeeeene 2 18 3 1

DIsciInbz—
Onbiciloideasspecies sana. <s seme cesses oes ae aac ee eae a oe ee eases ula Pens ee sae CDi ae raya 63 eat sie ae

CRANIDA—
ieniledrarispecioss-eemee-ceiescctsacis sce eacceeciere toceaectece tees | pee eaacee TIGER aE ceca seeds haad eee Amer ee Wt |ceosccoce

PROTREMATA:
BILLINGSELLIDZ—

INUSUSIAMNS DECIOS Sy ciee i asee c oe cise 5 cio cise ep oi sesie Sarees eeeseacee
Varieties... .... LE
(Jamesella), species.

Varieties... .-
Protorthis, species. -
(Loperia), species. .
Wimanella, species. . -
Billingsella, species...
Varieties ..-.-
Orusia, species. -
Varieties. -
Otusia, species-.
Wynnia, species
Eoorthis, species.
MMarietiese. =. sen
Finkelnburgia, species. - -
BViaTle LIESHMe Renee moni mene ccna ee eee ae ce tne

RO tAIBS PECleS See ears aes ae a eet ae see see 16 47 31 6 8 QM Resp 28 a
INO AIL EMTS oo55 connonoscasasnecedonascocononcsnuaeccess 3 1 Gy Bese cncitol|aooceosace loemGacacee 12

STROPHOMENID£—
IDO RA Vaasa, Goa Cans. scons coeaseso sea nqseamsesecoeteoHsas bacasreese bseseqsecalocsanaccss EE | ese ee Al eae

SYNTROPHID—
Swaultomia, Species! = == 2 22 -- 2-222. een
Syntrophia, species...

Varieties. _._._.
Huenella, species...
AViOTIETICS Reyaee me enna ene eta ta separa stsininte etIoee Greta lore tisiinieae
Motaltspecies sec asset ene eas see ee eks Sek Se cee Sec bse 2 6 Ue ete eee 1 Th Sess eects
ANON WRENS. 5 sasocnemose coos so coe ses ae sete ene asecensscd saconseens|porpocasos 7A Sone ns seal lbanenesoesesosscosee 2

@ One species passes from the Upper Cambrian to the Ordovician.

b Two species pass from the passage beds to the Ordovician.

c One species passes up from the Lower to the Middle Cambrian; two from the Middle to the Upper Cambrian; and one from the Middle Cam-
brian to the passage beds.

d Two species pass from the Middle to the Upper Cambrian and one species passes from the Upper Cambrian to the Ordovician.

€ Six species pass from the Middle to the Upper Cambrian, of which one continues on into the passage beds; one species passes from the Lower
to the Middle Cambrian, and one from the Upper Cambrian to the passage beds. One species is common to the Middle and Upper Cambrian and
& ihe Ordovician; one species is common to the Upper Cambrian and the passage beds; and one species passes from the Upper Cambrian to the

rdovician.

f Two velo pass from the Middle to the Upper Cambrian and one variety is common to the Middle Cambrian, Upper Cambrian, and
passage beds.

g Two species pass from the Middle to the Upper Cambrian of which one continues into the Ordovician. One species passes from the Lower
to the Middle Cambrian. '

h One species passes from the Middle to the Upper Cambrian; one species is common to the Upper Cambrian, passage beds, and Ordovician;
one species is common to the Middle Cambrian, Upper Cambrian, and Ordovician; one species passes from the Upper Cambrian to the passage
beds; one variety is common to the Upper Cambrian and the Ordovician.

2 One species is common to the Upper Cambrian and the Ordovician.

112 CAMBRIAN BRACHIOPODA.

Summary of Cambrian Brachiopoda by families.

= Genera, subgenera,
Cambrian. species, and varie-
ties.
Passage
beds. 7
; Recur- «one
Lower. | Middle. | Upper. Tent, | Distinct.
ATREMATA:
RuSTELLIDE—
Genera Doe oeeitaaa| scene cera Melseren apr baslastsene 1
Species WN oacnasaca ssabenHoe4seaucceboa|sdecmacuee 2
PATERINIDE—
Genera... 2 2 2 3 3
Subgenera. - 2 2 22 4 2
Species. . - eo Rees cette ene 15 20 7 |. 9 33
arieties 6 1 1 8
CuRTICouDA—
Genera Wisedesanuballboatacoded 1
Species Wl ocosonsomallesanaacené 1
OBOLIDZA—
Genera 4 3 3 8 6
Subgenera.- 5 5 5 8 9
Species 109 87 17 40 186
arieties 8 LOW Seer 2 16
KuToRGINIDA—
Genera 1G Ree aces sel aeons aacoe 1 1
Species Pil laeaoaseenc|saqoace taalaaadkeoooe 6
SCHUCHERTINIDE—
Glerierarte ees ser baie ese as hin! mae iseee eis baeieistec oe seen cle mesiorn a neeaislal eee weet ate Ue Sbescoraee eactmaccna secs sscoas 1
DECILES Hee em ieee eents Monee eye meses SG DOE SU POTeE CE amok BaD ase Senco crS oan] pearereas IN Reba oneal HoBHaacese|seacoorcos 1
NEOTREMATA:
OBOLELLIDA—
3 OH Ree nares ape aaeeeae 1 4
be Neeser Fa eas eine ce |e ee crea eee eames 1
14 Oi eaeseesse Seesacocce 1 18
DG SarB ates Soeacnecs seerocacalcaecoo ca 1
3 3 2 2 4 6
4 5 4 Sil eReaanaBoes 16
A 2 6 4 2 8 6
Subpemerae ey ee eee eee eS Vee SANUS eee cies rie piscine deisetneeer B BReceoones 1 AaeeeenHos HSSdaknssel saeco see 1
SPeCies ee ee NS Cee mera tee oe clea mne ae eis Se et Age a aad ae e 13 64 31 9 17 100
arieties...... SE aE eau Seiat ooe Seles mek pismeainemn Hue eeisee Selene emieeine 2 18 3 1 4 20
DIscInIDEZ—
(CONGR oC Sodunasaos casosr dobn doses Bodo Se aR oCE ba oesaaeeie cEsene none sneomeons Hoc seoaas i flscescossco 1 1 1
SHITE a sce bossa naseane pass odEosnsnoeosaseessEdesEEan sR dsb cBaSsebapEosobd aacouscese W oenssecose 4 |becoseuoos 3
CRANUDE— |
(COs SéSocesucghdak as oes oe ee cocucoSNocoade bab ber oueCda dS OEacne Spe cemba BSoseBesne 1 Reeser sec anseners| cecoanccae 1
RYORO CaS ash sedqrascanqacoseochele soo Sees aeenee Spee CUA eb aa EE SoDACHE Res SHE ecaaoensn Wi Kemasemcoelcbbescnoseleeaassascs 1
PROTREMATA:
BILLINGSELLIDE—
(COnGible Sadak Googe s SS COME CBR oR SR eu onane cer DOES RCaCECAEBeo- ce hem SSusteS 3 8 6 2 10 9
Subgenera, 2 1 2 il Ieosoccodes 2 2
Species.........-- 3 16 47 31 6 8 91
ALE TI OS eee eee ese ere eet ycbys atte = ioe shaeratnnieta St Sere se sinie feces mete 3 1 Dil beacadsoad| RRobictotcs 12
STROPHOMENIDE—
(COUGH 84 Ses ec seo BOOS RGR EER CE SR OCECEC SUE Sectao” Soecos eee aG AGS cneaeceds aenonbsoos MSecoetcee asarscucs Naleee esesass 1
Wes emasoded ouae a aoncdee bessCo ces robe bE bs HonaeHEteaaat aades aarecE sons) Getaeecoss Kasreatsnullasnnoncood NESS dioosee 1
SyYNTROPHUIDA—
COTO PRE trate incre a cinerea eins Sue Se Yc Me De ed se 2) erste 2 3
Species... I ape seosac 1 18
Varieties. . Pl Ses cecdaee lsaseoneces 2
General summary of Cambrian Brachiopoda.
Species
and va-
G Sub- | species, | Varieties, that pa
enera. | senera. pecies. | Varieties. ne Bass
the Ordo-
vician.
Atremata:
IRCA UGE. a a RS eRe A ore Sart as BOS En ana Asp aaetEohG aan shoancceconeSn en oncuee iti Scecaecens Dseaaceeec aanaconges
Paterinidze.- a 3 2 33 4 See onase
Curticiide:.- Us ees hs oe Th Ee aeeem ene basauasbes
Obolide...--. 6 9 186 16 12
Kutorginide. - Top aedgeae Gil pettanoace| seasceasoe
Schuchertinide Nees ceed il atesncseel hose tacos
Neotremata:
Obolellide...... 18 1 Bee eaapb Ss
Siphonotretid WN ecaacoce = 3
Acrotretide. . - 100 20 4
Discinide. -..- 3
OTA LER Se eee erates a aetciere octane ele a inks em nlcta ele cinco ela heii nate sa tie clarence since eiete 1
Protremata:
Billingsellidee 91 12 4
Strophomenide . AA eee Sars | See eras
Shania a aio bsis ee aoa UedaanemocenancuaseasocosonesHaecoasmeanenanacsononoroneusostsdoseen 18 2 1
WMI 352 cesangs so sdbcoccoodagesoone geass osndonoDobSohooooDS It deoO ROOnsaCEseooOORoTS 44 15 477 59 24

GENERAL GEOGRAPHIC AND STRATIGRAPHIC DISTRIBUTION.

SUMMARY OF ORDOVICIAN BRACHIOPODA.

The Ordovician Brachiopoda are summarized in two tables, one by genera and the other

by families:
Summary of Ordovician Brachiopoda by genera.

113

Species. | Varieties.

Species and
varieties
that pass
up from
Cambrian.

ATREMATA:
PATERINIDE—

S
Lingulobolus) @
Westonia)...-
Lingulella..__-
(Lingulepis)
Elkania ...
IDS 52 45.555 ssc sessessserosaNeS suedgodeasonnessHoaeueseee
NEOTREMATA:
SIPHONOTRETIDEZ—
Schizam pone tessa sas sale ees Soe se tee sea Snoseoadscancedasadausanaoaucnescscese 3
Siphonotreta arse
ACROTRETIDE—
PANCrOtHe eer cemn nen sae ce cote hese = Se aisin cio aes
Linnarssonella

BILLINGSELLDE—
Bilin esellayme meee seceeiesclas <aeer ce sec = smeeese eer ae ee eeieeeeceer cciseeiecece aeeeene ets
Eoorthis. . .-
SYNTROPHUODZ:

Nem pwr

Syntrophia. a le
Clarkellaa .. 1
Total....... 64 3 24
a Found only in the Ordovician.
Summary of Ordovician Brachiopoda by families.2
Species
and va-
Sub- : 5 rieties
Genera. Species. | Varieties.| that pass
genera. up from
Cam-
brian.
Atremata:
TPBNIOHTENC RD oc cosag oso ecogooss0s ae Seno sHoNs So So sSagS5aNSDOSOAS DONSOSsOODDEsoSOSACSsoSaaase It oneoescoas 1 eae es Reneeso co
ONO ES ~ son s5a050 2onese sone sso 2s Has DcO Coos estos tsoRosaSSNSooDASHOSNSHOSTEsesobseSdcasce 4 3 41 il 12
Neotremata:
SHOIEOMTOMG HCE. 5 cre gota coseensbosasanssce sao seiussesecrcesesdocdont sconssecsnosaseasase 2 \locaco=eos= BS Een ste oe 3
ANGHOWMANCED, «os coco qscsseacoengisssss00 shod coo SsbossnosaqUEssaOESaSoSSoB=GeOswSaeNEsooNS Bl edasaanes 10 4
Protremata:
GNU SANGH 5 soc sacseogeodes asco sse Sse sos ozo geese nc onsee sotssSs toca redasdas=seneoNs % |osousecoes 4 1 4
Syntrophiide.........-...-.-------- ------------------ 5 sor eoscoasoosesosoeossraoasconss 4 || sseeco555 Cn Sear Becsiod 1
HINGE borane coesoe snopes sca. qo aSabe a ION An OSA RHES sn anssanesosene apaeduspocHeSssebbes 14 3 64 3 24

a This table includes all Ordovician species taken up in the monograph. With the exception of three genera, one subgenus, forty-two
species, and one variety all of these pass upfrom the Cambrian. (See pp. 122-123 for a list of the Ordovician forms taken up in this monograph.)

GENERAL SUMMARY OF CAMBRIAN AND ORDOVICIAN BRACHIOPODA.

The following table gives a general summary of the genera, subgenera, species, and
varieties, both Cambrian and Ordovician, in each of the families taken up in this monograph:

General summary of Cambrian and Ordovician Brachiopoda.

Genera. | Subgenera.| Species. | Varieties.
Atremata:
IR(PRS GIG ED. . 5 song sooecosnso us seo seaae cou 57 ae beer ao meade ober ebas ates Sonne Mogbbeacsoossanescecce W ococeceseose DIE Same oo
Paterinidz. . 4 2 34 8
Curticiidee. il lenoasoeacsen i esacessacsog
Obolide- .. - < 7 10 215 17
Imi@Wattal Ge. 52 .ceseacee Saree Coes beeses Sa eSoe He Boao se Se See EH Oo as ao - eet doo ghodermoseaatsnsee i eacsenccossd GO iosooasedses
Neotremata:
CHUCHeRtinid eae ee ace ee ese sae a se ensissoe = ase ee see ee ery Jgssososdbonsessceassoace Ul |losososesstos 1) Ses eacuanee
Obolellidz...... 5 4 1 18 1
Siphonotretide. F ococsetooose IY fil eeRoaeeictase
Acrotretide. .. = 6 1 107 20
IDIEOMIGED: 5 - so sopsnce ons esseese ds = 2d SSO SAS EERE BUSS Seco DERE ae oS 5s soc corer ououceBbsconeSsSnne U pesesesssese G)) Seenoraceee
CCRTITG ED: 3252. deena lease co neeL PE ASEE RROD: - oA REM SEPOBO ABER So sHa sc dose GSanaba ease ae oan scae I posaccscesse by SeSeasepocee
Protremata:
BNI PSel li dee ee tern clare ce ceo soe cyte ois. See acs Syatel ne ee a te ER ANU a eee 9 2 92 12
Strophomenidz. 7A eiccesacaeec i; | Raat geste ss
Shwe a NC a. sede tse Se adecee oem see. eo Roe SEBE Banana se-4ebes soanaeesce mec one bese ance (nl ecebesaes ie 21 2
ALOUE oe Sh conmesndenqec Bas mosn acess snes pa dceasa Hamceaas bomscsaietigns doses necockndeneLaie 47 16 519 60

62667°—vot 51, pT 1128

114 CAMBRIAN BRACHIOPODA.
DETAILED GEOGRAPHIC DISTRIBUTION.

In the following lists the various species of Cambrian Brachiopoda are listed by continents,
as they occur in the various faunal provinces of Cambrian time in North America and in other
countries. The record of the local distribution of each species will be found at the end of the
description of the species.

The tables are arranged under the following heads, the species being zoologically arranged
under each head:

1. North American species of Cambrian Brachiopoda (p. 114).
. European species of Cambrian Brachiopoda (p. 120).
. Asiatic species of Cambrian Brachiopoda (p. 121).
. South American species of Cambrian Brachiopoda (p. 122).
. Australian species of Cambrian Brachiopoda (p. 122).
. North American species of Ordovician Brachiopoda (p. 122).
. European species of Ordovician Brachiopoda (p. 123).¢

“IO Or # co bo

CAMBRIAN BRACHIOPODA.
NORTH AMERICAN SPECIES.

Note.—The letters placed opposite each species in the various columns denote the State or province in which the species occurs; for instance,
a ‘‘C” in column 2 under A indicates that the species occurs in Cape Breton, ‘““CN” indicates that it occurs in -both. Cape Breton and New
Brunswick.

A. B. C. ; iigeeDe

Atlantic A

_| Appalachian proy- Rocky Moun- P A 4
i gonst DEY: tale. tain province. Interior continental province.
|
3
°
2 Te |e) es} als 2. 3 4, Al 2. 3 1 2. 3. | 4. | 5. | 6. 7.
=)
3 eee pial yal
is ES &) > co} oth ko) Lo} us)
2 5 |S : |\3a/ a I= q q 6| qa
3 2 ie )o).2 |e] * pag plies a8
3 Bae |e lea ate é |5| 3 Bl as
e I, 2a| 7 ee] 3 Gi 3 5 | 5 S| as
3 Sele 13] & [25] Ba Ja Ba g ‘do
Pt SSls slo] © 58 8 Se : Be] 8s
q olElcsye | 2 5u| 38 |es CAR q 3 & | Sa
5 B18 : 2aly|o M8) O8 [85 ge |2|S8 4 | ba
de SiS s\oa] 8 Aa ise S fla a3 a me s/Fa

= SS] ire) a
2 3 a g eel, Salles oa 8 -|25 78 q a eI cS
s ae Ca tse sla [2 |e|P fele jerks a| $3
is S S Ss = aie D S o at 2) eis ii Sl 3
B jEl2 2 18| Blesis (2 |else [8/8 |8lSieisis
= O15 |S Gy oS |2S| 3 =] S| SI Sales a |/M)o |e | 3
a 4/6 @ Jal] > 2a fia le /8. Jole Js lojal4]s

Rustella edsoni Walcott.-......-....-----
mae y OP (CMERHANEN 52 sos eesecene ndoa=6e
Mickwitzia occidens Walcott.........-.---
Micromitra alabamaensis (Walcott). -...--
hay deniaWalc0tt-ss-s-— esse eee
DISUS|(NWalcOtt) memes eee eee ee B
pealel@Walcoth) pees seeeeeeeeeeeeeaees
sculptilis (Meek)....-....-..--..--.-.--
sceulptilis endlichi Walcott.-.-......-. Cc
zenobia Walcott.....-...--
sp. undt. Walcott
Micromitra (Paterina) bella (Billings). ....
lexenistrial @Wialcoth) sseeeeeeeeeeeeeeeee
labradorica (Billings). ................

labradorica swantonensis (Walcott)...| B
labradorica utahensis (Walcott)... .--
labradorica var. undt. (Walcott)......
lopanil (Walcott) eee eee eens
MAORI OVAlCOUD mee eeee net see nee
prospectensis (Walcott)..........-...-
Stissingensis (Dwight)............-...-
Stissingensis ora Walcott-..............
Stuarti Walcott... 205235. 225 Sees
SuperbaiGwalcott) sso ssee es ene es eee
Wap lapWalcottoessseeees meee ne eeeee
WwalliandmiWalcotisnesesee eee eee se enee
Micromitra (Iphidella) louise Walcott... .
IY SSARYVGICOLL mene ae eee eee Cc
ornatella (Linnarsson).............-.-

pannula (White).....................
pannula maladensis (Walcott). Eee
pannula ophirensis (Walcott).........

@ Only those taken up in this monograph.

DETAILED GEOGRAPHIC DISTRIBUTION. nS

Geographic distribution of North American species of Cambrian Brachiopoda—Continued.

Note.—The letters placed opposite each species in the various columns denote the State or province in which the species occurs; for instance,
a ‘C” in column 2 under A indicates that the species occurs in Cape Breton, ‘“CN” indicates that it occurs in both Cape Breton and New
Brunswick.

A. B. Cc. D.
Atlantic
Appalachian prov- Rocky Moun- . . .
L proyv- . * = Q 7
a coast proy aicee tain province. Interior continental province.
g ince.
|
g =
i=) |
1 il 2.) 3: 9 1 2, 3. 4 1 2. 3 1 2. 3. | 4.) 5. | 6 7
o
vo | ———"
for S >
a pb \2 3 .| 3 a us) Zz Fi cs}
Ss ; i S
4 2 8 4 fae] a [5 ee sll 8\&
S fs [3] ¢ jE co! > Bl By ie
o 2 PH ja Go} oe q s oS); 3 a ob:
q Se te | ew Teel & = ve) || & s/s
z sze4ée| 8 jBc| Sd (2 cale| 3 e| as
tS} : ‘iad Sg hs Ors D ° a ax
a Slagleelo| S (el Ss Be ae |24/| 8 % | 88
qd 8 logieSia S Esoel 2 o sa ]5/| ao colt
cal eI 25 Sale| & |S3] 5S se Gini | (ast | eo! 3 eels
S Amale [Sia les) eo |s/Ss° sia leig = || 38
I 5 jo JU B jos! a fa] | = gt |] I 5|¢ S| op
43} Ia 3 mp] oO ) s 21 ic} as ao =| a
5 Slo |a =I gf) Sas 4 = g 3 5) 9 3 | °° 5
5 Bln, |@ | 2 BE IES) qa = gi; 4 5S | aS | eis | 3
= ois |S a Oo os] o "a S) Ss qd Raul a |S a || gst S
a 4\0 ja fal] > ae A |/4a/8 o/s al/O;el1<4]/o0

Curticia elegantula Walcott.....-........
Obolus acadicus Walcott. -......- on
discoideus (Hall and Whitfield)
fragilis (Walcott)..........---
ismene Walcott... --
lamborni (Meek) -..-.--.--.
Jamborni minimus (Walcott) .
Joperi Walcott. -...---2---.-
Tocconnelli (Walcott)....._-
meconnelli decipiens Walcott.
mcconnelli pelias (Walcott) --
mera (Hall and Whitfield) - - =f
_matinalis (Hall)---------.------------

membranaceus Walcott. ........-.---
mickwitzi Walcott... .-.-
namouna Walcott........
nundina Walcott.........
pandemia Walcott.......-
parvus Walcott----
pheres Walcott. -.........
prindlei (Walcott) -...-...-
Tefulgens Matthew. ---...---
Thea Walcott. . ---=..---..-
rotundatus (Walcott) ....--
selwyni (Matthew)... ---- ze i
septalis (Walcott) .-...--.-- z
sinoe (Walcott) - 5
smithi Walcott. -.
tetonensis Walcott... . -
tetonensis leda Walcott... --
tetonensis ninus Walcott. - -
? torrentis Matthew. ......-
willisi (Walcott) -.....-----
wortheni Walcott..........
zetus (Walcott)..--...----
Sp und bee sea. - ke
SP Gidea esses Ss oa eee Ce

Obolus (Broéggeria) salteri (Holl).--..-.--

Obolus (Palzobolus) bretonensis (Mat-
thew).
bretonensis lens (Matthew).--...-.----
Obolus (Fordinia) bellulus (Walcott). --..-
gilberti Walcott_............. oP
perfectus Walcott.-..-...--.--
Obolus Sat) Tugatus Walcott. -
Obolus (Westonia) aurora (Hall) -
chuarensis (Walcott)......-
dartoni Walcott..........
ella (Hall and Whitfield).
ella onaquiensis Walcott
escasoni (Matthew)...
euglyphus (Walcott) -
iphis Walcott..........-
stoneanus (Whitfield) - -
themis Walcott........---
wasatchensis Walcott...
sp. undt. b Walcott......--
Lingulella acutangula (Roemer)...
ampla (Owen).....-.-------
arguta (Walcott)-.-.....-
atava (Matthew).......--
atava insulz (Matthew). -
auga (Walcott).........--
bella (Walcott).......--
bellula (Walcott) ........-
billingsiana (Whiteaves). -
buttsi Walcott.......--
cania (Walcott) -...----
clarkei Walcott--......-
collicia (Matthew) -..--- oe
concinna Matthew........------------ A and Eu-|-_..-

Sire

ue lSf \S)o 6

BONBON > COOWBOPWOPryOWoNya

Peel [el ollololetol =

mo

PObt> pb bb ObacobwaY

116 CAMBRIAN BRACHIOPODA.

Geographic distribution of North American species of Cambrian Brachiopoda—Continued.

Nore.—The letters placed opposite each species in the various columns denote the State or province in which the species occurs; for instance,
a ‘©’? in column 2 under A indicates that the species occurs in Cape Breton, “CN” indicates that it occurs in both Cape Breton and New
Brunswick.

A. B. C. D.
Atlantic Ain 4 F :
é coast prov- appalachiag DrOV PS Interior continental province.
ince. s ;
3
°o
& 15) 5 ES | [al Rl 3 4 ie |) 2a) 8 1 2 Sol een |e |G if
= t io} o
SE eae | ee s| 3
S) Ze ly 2 B lag| = oJ nd > ran lcs
3 o CO) |Sse=! Z > a oS oO ~
3 [oct @] [bo S| s © || = s oh
a leash ia aS he || a. 47] 3 aS
= se\g 15] 5 |gel od Is Ge els Eiles
ie 3 |_s\°s12 | 2 [ss] 28 [es Paria) (al els Z| 2s
, |2 (84282) = Rel oS [Bz] | 22 |G) 38 a ee
So lg leseels| 8 |g) oS [s*| | 82 12) am a) 2)
g 5 |se B15] es [28] 3 [5 |a]/s0]e| 2 = | 3 & | Se
& lsh i isl 8 ele |e |ele Pele 1S2)Gl8 isa
5 lela |2@05/ & lesle [2 |e|2 [8/2 |2lsisisis
2 o|R if fal] & |S) 8 ee | & I || 2 4/4/31] 5
4 ats jel (Si) = bee ei 4a |si-8 o| sa/O/aeal4/5
Lingulella—Continued.
cuneola (Whitfield).....-..... AD saaessecnls Detel Resa al Wee -| Heats boars peal erase Paose Basel eccnad Wns seasecs Ss
davisi (McCoy) ..-..-..-------- -| A, Hurope,|----] © |....]----]..--.- BE aAl Ree See (hoes Ree Bercead Herel bacgocs Bie Semel pe peel eae
Asia,and
South
Y America.
desiderata (Walcott) ................. RES CEL) | Sees ee rode a eet ed [ee A GUANA © || M00 | BTN (Cig Ise) Eanes IMF eee ws
and Ord.
dubia (Walcott) .............-..-.--.- Cc 66e) (eel eee KOA Sess! eee ines al Wenner DNF) Betsel Meeeiseiel ists Pe! Ieee sor Meats (Sc aoe
ferruginea Salter.-.-....-.--.-.--..-.. t INTEC IND | RAPS BSS ET ea Ee eg eae Bye] Scie esta IS | Ed | Ta |e | ie

flumenis (Matthew)

franklinensis (Walcott)........
granvillensis Walcott........--
hayesi Walcott......---...--
helena (Walcott)....-....-..
ino (Walcott)....-.........-
iris (Billings).-........-....-
isse (Walcott)...........-.--
levis Matthew..............
levis grandis Matthew......
lens (Matthew).-...--.---.--
leos (Walcott) .
lepis (Salter) -.

lineolata (Walcott)
manticula (White)
martinensis Matthew -...-..-
minor (Matthew).......-..--
Am Osioy Cela) See eens
mosia osceola (Walcott) -...-.
nanno (Walcott)
ora (Walcott) ...--
oweni (Walcott)
perattenuata (Whitfield)...
phaon (Walcott).....--....-
pogonipensis (Walcott) ......
(prima) (Hall) See eee ee ee
punctata (Walcott).........
quadrilateralis (Walcott)... -.
radula Matthew-...-.........
randomensis (Walcott) -..-..--
rotunda (Matthew)-.......---
schucherti (Walcott). .
similis (Walcott) -.._..
tarpa (Walcott) -.
texana Walcott. --.
torrentis (Matthew) .
triparilis (Matthew).....--.---
tumida Matthew....-......---
upis (Walcott)......-..--.-..-
welleri (Walcott)...........---
winona (Hall).................
winona conyexa (Walcott). .-- 2
Sob Wisin, 10) VVEM CoN oes sco c ccs en
Pingel (Lingulepis) acuminata (Con-
rad).
acuminata meeki (Walcott).......-..-
exigua (Matthew) -.........---
gregwa (Matthew)......--.---
Tegwa robusta (Matthew) ----
longinervis (Matthew)
pumila (Matthew)... -..---
roberti (Matthew). -
rowei (Walcott).......-..-...---
spatula (Walcott) -
Starri (Matthew) -.....-.---------
Bicia gemma (Billings).........-..-- Z
whiteavesi Walcott.-..........-..-...

helo} ehe la:

5 Oh aby, Ioesallssadibesd Fasc) Wan Hui Been
and Ord.

ice}

DHPUOPP E> bry

a Lingulella (Lingulepis) acuminata also occurs in Michigan.

DETAILED GEOGRAPHIC DISTRIBUTION.

Geographic distribution of North American species of Cambrian Brachiopoda—Continued.

117

Norr,—The letters placed opposite each species in the various columns denote the State or province in which the species occurs; for instance,
a “C’ in column 2 under A indicates that the species occurs in Cape Breton, “CN” indicates that it occurs in both Cape Breton and New

Brunswick.

Dicellomus appalachia Walcott
nanus (Meek and Hayden)

pectenoides (Whitfield)
politus (Hall)...........-...--
prolificus Walcott 3
Kutorgina cingulata (Billings)......---.-

granulata Matthew..........--------
perugata Walcott. - a
sp. undt. Walcott.....--
Schuchertina cambria Walcott.
Obolella atlantica Walcott. -....---
chromatica Billings........---
crassa (Hall)....-------- é
crassa elongata Walcott. -
minor (Walcott).-.....- Be
vermilionensis Walcott. .....--
Botsfordia czelata (Hall)...--.-..-
pulchra (Matthew). -.-
Quebecia circe (Billings) - - . noe
Yorkia wanneri Walcott........--
? washingtonensis Walcott - -
Dearbornia clarki Walcott.......
Trematobolus excelsis Walcott. .
insignis Matthew. ....-....--
kempanum (Matthew). -----
pristinus (Matthew) --.-.-----
Schizambon priscus Matthew - - -
typicalis Walcott............
Siphonotreta? dubia Walcott...
Acrothele artemis Walcott
avia Matthew...----
ayia puteis Matthew.
bellula Walcott......- BS
colleni Walcott............
decipiens Walcott. .......-
dichotoma Walcott. ...--.-
gamagei (Hobbs). ..-----
matthewi (Hartt)....--..-
matthewi lata Matthew-.....-.
matthewi multicostata Matthew-
nitida (Ford)....-..---------
panderi Walcott......-
prima (Matthew) ...--..-.
prima costata (Matthew)
proles Matthew....--..-
spurri Walcott... .
subsidua (White)...
subsidua hera Walcott.
subsidua levis Walcott -
turneri Walcott.....---
woodworthi Walcott.
yorkensis Walcott.
sp. undt. a Walcott... .--
Linnarssonella girtyi Walcott ae
minuta (Halland Whitfield).........
modesta Walcott...........-..-------
nitens Walcott.......
tennesseensis Walcott.
transversa Walcott...
urania Walcott.....--.
Acrotreta argenta Walcott

attenuata Meek

attenuata var. Walcott.........-..---

baileyi Matthew

bellatula Walcott. -

bisecta Matthew

?? cancellata Walcott

claytoni Walcott...............----.--

a This species also occurs in Virginia and Maryland.

A. D.
Atlantic .
Appalachian proy- Rocky Moun- - 5
é Const Eros ace” tain province. Interior continental province.
Zi b
[>]
3 = ts
g ik || 2 || 3 3. 1. 1. 2. 3. | 4. | 5. | 6. Ub
E este |
a > |o . |e .| 3 b ko} g s|/ sz
4 ag 4 les] ¢ 1s E Blin $| 3
3) Zz |S a a lig S aye) ot )
3 H) © iss Z > Hm | oF im
e PP 2] A fob) oS q cs o|s S|
a Ss. 2 Be! S a 3 ae) al) as
Ss) als a B |4iS) bo. Ss A =
Ss ao|d .. 5 & 1s a eo) ead Je | & z| ae
i -|Selsci@}] = jaa] § Bes 2a 1 >| 8 = a
Ee SlaBleals Seals 5 s 4e 12/28 z 2s
5 H\SaZaIg | 9 PS| OA TBS ee) |) ie 2 ie
2 |sleeea12| 2 lS] ss jel .| Se] 8) = | |8|"8
o g Lyon] =i 5 ~ oA) 2 ‘S) a 59 S = a g Cs ~s
° FAR |S q @} 2 ° 4 3 iS }K>)
5 2 = |z Br ics 2 a a =“ 4 d|s ; ksi)
I elo S 1E| gles 2 12 |2/8 [2/8 [8/8/2181 8
° ela, |2 2 Sa) g = is| = + 2 YA || Sy mw |S iS)
= o |e s 3 oO os) © = i) 3 g at wt | Ad 4) fa} 3S
a Zio lf tale ale je |se|S Pole Jalolael4|/s6

118 CAMBRIAN BRACHIOPODA.

Geographic distribution of North American species of Cambrian Brachiopoda—Continued.

Nore.—The letters placed opposite each species in the various columns denote the State or province in which the species occurs; for instance,
a‘‘C”? in column 2 under A indicates that the species occurs in Cape Breton, “CN” indicates that it occurs in both Cape Breton and New
Brunswick.

A. B. C. D.
Atlantic RK : :
i ppalachian proy- | Rocky Moun- = B e
é coast Prov: inca tain province. Interior continental province.
Z| ince.
Oo
oO
fo}
3 1. | 2.) 3.491 2, 3 4 1 2. 3 1 2, Bm |) 25 i) ab |) © 7.
: | p ~
a I |} lied alll 3s) au us} ue] 3 |
5 ) ww aa >

5 ale/e Es. |e ey elles g|
iq is) 2 Pe! Ss q 3 Est |S) = | a
3 au/o 2 me |a@] i. Ss. n 4s
= Sif 15] 5 ISF) Sa Is Poa fe | gy E °
| Sele al S a aS ||. ey e I 4 es BY
= ai E\os Z |5¥\) of Jaa rars| o 3 on
4 qd leo £ 8 gio 2) O& ge 16 14 ge 4/ Ba

iS} ws is} jeu GI gaid ©) g/ FE
32) Sle s/oalsg =| : 8 [=a as “ : a
g Sees te | S [ee] e318 |5)|S6]8] s .|¢ Bl =
& Sips 7S] 2 |ks| a ee o | 4 <i || = a| So
q S) ke} ic) os! a 4s) = ~ 4 =| 3 o “ sien)
ig 2 a le 3 a ce zg a fy s B S i} = 8 5 S|
e = & s q = % , S
& EIS |a 2 BES) Sg = a 5S) || I i iroh Eells) ‘S)
=I Sis Ss a ® od oO | iS) i qi teal | a fa r=
a aii pale iatle ia (Sie Pole (Sele ieis

Acrotreta—Continued.
concentrica Walcott. .-...:.-..-------
convexa Walcott.
curvata Walcott...
definita Walcott...
depressa (Walcott) -
emmonsi Walcott --
gemmula Matthew -
gracia Walcott... :
idahoensis Walcott...........---.----

idahoensis alta Walcott...............
idahoensis sulcata Walcott.
ef. idahoensis Walcott... -.
inflata (Matthew) -...-
kutorgai Walcott.--...-
marjumensis Walcott. --- zs
microscopica (Shumard).-.........---
microscopica missouriensis Walcott. -
microscopica tetonensis Walcott. -
misera (Billings).........-.----
neboensis Walcott. -

nox Walcott......

ophirensis Walcott... .......-
ophirensis descendens Walcott -
ophirensis rugosa Walcott...
ef. ophirensis Walcott... ...
primzeva Walcott...
pyxidicula White.

rudis Walcott... --

sagittalis (Salter)

sagittalis magna (Matthew). -....-...-- A
sagittalis taconica (Walcott) . eS
sagittalis transversa (Hartt) -
Clase pit ballisse seer ee
signalis Walcott - -
spinosa Walcott. -
ulrichi Walcott...
sp. undt. Walcott... _--

Acrothyra minor Walcott...
proavia (Matthew)... .
sera (Matthew)...
signata Matthew... ..
signata orta Matthew---.-
signata prima Matthew-..-

Discinopsis gulielmi (Matthew) - -

Philhedra columbiana ( Walcott) -

Nisusia alberta Walcott. .......
festinata (Billings).........
festinata transyersa (Walcott).
Marae alco tae eee ee

Nisusia (Jamesella) amii Walcott.
argenta Walcott...........
erecta Walcott. ........
? kanabensis Walcott. -
lowi Walcott..........-
nautes (Walcott)...
spencei (Walcott)...
utahensis Walcott -
sp. undt. Walcott.......-

Protorthis billingsi (Hartt) .
helena Walcott.
levis Walcott.........
latourensis (Matthew). . .
quacoensis (Matthew) -- -
wingi Walcott......... She
SDSiLING ea Wicl CO Uae eee eee

Protorthis (Loperia) dugaldensis Walcott.

Wimanella? anomala (Walcott) ..........
harlanensis (Walcott) Se a Recae a3 ae ecllos ne BAA se54\a50 2
AN VOENSISWAlCOLL: See hse eee Gem esel. dU Ohare mete Sed eee erat ee Se Se hares tctam ee ere eee he tl AIMEE Ere prec oes ee eae ne eaeees

Tee An as eee

DWP Od eur DOOOQbFOWONWOOS PPP PP OrUs

2 eo

DETAILED GEOGRAPHIC DISTRIBUTION. IES)

Geographic distribution of North American species of Cambrian Brachiopoda—Continued.

Norr.—The letters placed opposite each species in the various columns denote the State or province in which the species occurs; for instance,
Bae in rectum 2 under A indicates that the species occurs in Cape Breton, “‘CN” indicates that it occurs in both Cape Breton and New
Tunswick.

A. D.
Atlantic .
_. | Appalachian proy- Rocky Moun- A B a

A coast prov ae. tain province. Interior continental province.
5 ince.
oO
oO
fo}
3 1. | 2. | 3 3. il, 1 2 3. || 4. || 5. || 6 7.
2
5, —|—
a & |o a lial! = ro Z ala
FI 2 ig 4 les] 8 |< A 9 || & 2 | &
E 2 |5| 5 \se . eels ie
o eat o en | 0 es S| s ° “s) 8

iS 2 Be 3 a io} i ie} =| s
q Sulo [oO] = lac) m. a.gr | 8 + | 8s
8 aaa Js] 5 |s>| Ba Is eS Pe | & 2| 882
ts || eye" C| z |fs) 38 [Sa zeal2®| da 2 | S's
B Slaelesio| o es] os [ee ‘B14 | ee 4) 5A
| S/SRSel a | g feces pele a2 fsa] as ga) Sa
srt oa i> Ss1S4is a |>cl| <= Ise Sa | a al j a 3
o x Eo I me Sie) os S Ss || So a | 8 : q 3 on
oO (22) eel hes] So = Hol a e Pr Q = 3 S
< 3 SS Solel es ia es souee alec eleculeei lel”
5 Bla |2 se] & Be a |= |2/4 =| 3 B\S)8/8| 8
a a g 3 Oo oS (a) = = =| a fi] ~ a A fo)
AY 42\o lf] Jal > ate ia jal s o| = a/Ola|/4] 0

Wimanella—Continued.
SatLonginG@VValcOtb) semen sere eee eo =e
shelbyensis Walcott -
SsumplexWaleottes. -sss---------------

Billingsella? appalachia Walcott......-..-
Joe VV O lh 2 Goce eee See eR sees aeeaS
coloradoensis (Shumard)------.-.-----

highlandensis (Walcott) .........-.---
AMaJORAVVAICOLL = sasyeisyseise ee soca - =
marion Walcott.
obscura Walcott. --
orientalis (Whitfield) -
plicatella Walcott..-..............--.
retroflexa ( Mines Beene tae cas seose
salemensis (Walcott
striata Walcott....-..
whitfieldi (Walcott) .......-....--
Orusia? eurekensis (Walcott).......-.
lenticularis (Wahlenberg).....-.--

lenticularis atrypoides (Matthew).....| A
lenticularis lyncioides (Matthew) -
Otusia sandbergi ( Winchell)
utahensis Walcott.......-
Eoorthis atava (Matthew)
desmopleura (Meek) .......--.---.---

desmopleura nympha (Walcott) ......

? diablo (Walcott) ..--..-.-----------
hastingsensis (Walcott)... ----

iddingsi (Walcott)........---.

indianola (Walcott).......---

johannensis (Matthew). . . --
newberryi Walcott.......--
newtonensis (Weller).....--
papias (Walcott) .........--
remnicha (Winchell)... --.-
remnicha sulcata (Walcott).
remnicha texana (Walcott). -.
remnicha winfieldensis (Walcott)
thyone Walcott.....-.- :
wichitaensis (Walcott) ......- en

wichitaensis lzeviusculus (Walcott) - - -
ZEDOMVMAlC Olsen nee eee eee
Finkelnburgia finkelnburgi (Walcott).....
osceola (Walcott).........-.----------
osceola corrugata (Walcott).
Swantonia antiquata (Billings) . ae
WweeksisWialcott seo 255-8255 25. 22
Syntrophia alata Walcott...............-
barabuensis (A. Winchell)......--..---
cambria Walcott. -------2------------
campbelli Walcott.........--.--------
MundinayWalcottsess ss see essa meee
primordialis (Whitfield) -..........---. D
primordialis argia Walcott.........---
rotundata Walcott.......-...--.-----
PiinxianWaleOttesss esse. a= ace Cc
Huenella abnormis (Walcott)........-..--
billingsi (Walcott)............--------
lesleyi (Walcott) .....-.-.------------
texana (Walcott) -
texana lzeviusculus (Walcott) -
vermontana Walcott... 3

120

Nore.—The letters placed op

instance, in the third colu

CAMBRIAN BRACHIOPODA.

EUROPEAN SPECIES.

Geographic distribution of European species of Cambrian Brachiopoda.

osite each species in the various columns denote the country or province in which the species occurs; for

mn an Eg” indicates that the species occurs in Sweden, “‘SF”’ indicates that it occurs in both Sweden and Finland, “etc.

Nor-
Eng- way,
land, | Swe-
Scot- | den, | Russia
land, | Den- and

Treland,| mark, |Poland.

and and
Wales. | Fin-
land.

Prus-
sia.

Bohe-|Baya-

mia. | ria. France.

Sar-
dinia.

Mickwitzia formosa (Wiman)...-......-.....----.-----
Mmonilifera (Linnarsson).....-.- z

retiosa Walcott...........--..

sp. undt. Walcott.........-..-

Micromitra puss (Linnarsson) - - . -

BIG —nancscoocasceonscosss
Micromitra (Paterina) labradorica (Billings). -
jolouid best (ISI@ UD), oe ces cesessacanscese

scotica

undosa Crone Nes
Micromitra

Obolus apollinis
Saal ingricus (Wiel

apollinis maximus Mickwitz . .
apollinis quenstedti Mickwitz) .
? bavaricus (Barrande) .....-..-
eichwaldi Mickwitz-..-......-
elegans Mickwitz........-..--

2inflatus Westergard
?meneghinii Walcott

? minor Barrande ........-.--

? palliatus Barrande .
panderi Mickwitz. ..-

schmalenseei (Walcott) -....--
schmidti Mickwitz.........-
triangularis Mickwitz......-
volborthi Mickwitz.......-.
? zoppi Walcott.........-.--
spHumdtie: Soe eoee. ose eecsece
Obolus (ineeene salteri (Holl)....
Mickwitzella) siluricus (Hichwald).........---|..--.-.-
Obolus Sonne antiquissimus (Hichwald)...-.....-.- by
Schmidtia) acuminatus Mickwitz.

Obolus

Obolus
celatus (Volborth)
crassus Mickwitz .

obtusus Mickwitz.............
Obolus (Westonia) dlandensis Wa)
balticus Walcott: ------22-.----
bottnicus (Wiman).......
finlandensis Walcott. .
wimani Walcott............
Lingulella agnostorum (Wallerius).

ornemanni (Walcott

cedens (Barrande)......
concinna Matthew.....-
GAaVISi (MICCOT) ee eee oy Seatac ae aie a

delgadoi Walcott. ..-
ferruginea Salter. .-..

ef. ferruginea Walcott.

? humillima (Barrande).........-..-------.-
lepisi(Sallter, )aagveseee sean cieesiae omens seiicte
linnarssoni ( Walcott). - -

nathorsti Linnarsson .

-nicholsoni Callaway -

? primzva Hicks...
siemiradz ii (Walcott

signata (Barrande)..-

wirthi (Barrande)...
zeus Walcott.......

Lingulella (Leptembolon) linguleeformis (Mickwitz) ---
Lingulella (Lingulepis) pygmeea (Salter)

? squamosa (Holl)...

Delgadella lusitanica (Delgado)
Dicellomus sp. undt. Walcott..........--.-...-
Kutorgina sardiniaensis Walcott .............-
Obolella? lindstr6mi Walcott...........-....--

mobergi Walcott.) 222222225. oe

? sp. undt. Walcott.

Obolella (Glyptias) favosa (Linnarsson).....--

Botsfordia? barrandei W

Yorkia? miqueli Walcott ......-
Schizambon? esthonia Walcott

Siphonotreta unguiculata
verrucosa (Hichwald)

Keyserlingia buchi (de Verneuil)-.......--.
Acrothele bellapunctata Walcott.........-.

bergeroni Walcott...
bohemica (Barrand

borgholmensis Walcott.

ceratopygarum (Brog!
coriacea Linnarsson. .

intermedia Linnarsson.........-...----

maculata (Davidson)
primeva (de Verneui

Tphidella) ornatella (Linnarsson)
Volborthia recurva (Kutorga)......
Helmersenia lado eeeusis (Jeremejew)

Icha laa ees eee se miceerreeececs

hwald) .

Dy:
cokesbeohaei-ok-=

yee

se weep eter a laste ees

EVCGrey HOB Repco PO Baa mH Te Yer

(Bichwald)......--

BEL) ees sne eon ee A PeINSia Rees aks

(rand BB anrein cle) Weer sc cereus | eee erate eee ets

Also occurs in—

_| North America.

North America.

_| North America.

_.| North America.

North and _ South
America and China.

North and South
America.

-| North America.

Ordovician.
Do.

ee

DETAILED GEOGRAPHIC DISTRIBUTION.

Geographic distribution of European species of Cambrian Brachiopoda—Continued.

121

___,Notr.—The letters placed opposite each species in the various columns denote the country or province in which the species occurs; for
instance, in the third column an ‘‘S” indicates that the species occurs in Sweden, ‘‘SF”’ indicates that it occursin both Sweden and Finland, etc.

Nor-
way,
Swe-

den, | Russia

Den-

mark, |Poland.

and
Fin-
land.

and

Prus

rus-| Bohe-| Bava-
sia. | mia.

ria.

France.

Acrothele—Continued.
quadrilineata Pompeckj...........-....-----------
villaboimensis Delgado
IS Dede MO DELP eee ne ne cece acmeccercecerence
Acrothele (Redlichella) granulata (Linnarsson)
Acrotreta belti (Davidson)..........-...--.----.-------
carinata Segerberg........-.-.---
circularis Moberg and Segerberg. . -
conula Walcott..........-...------
eggegrundensis Wiman.......-.-.-
inchoans (Barrande).......-.----.-
nicholsoni Davidson......-....-.-- Aan
olandica Westergird...--....--.-- Sad laasesasg
parvula (Wallerius)..
sabrinee (Callaway). -
sagittalis (Salter)... . on a”
SORTA GSE WENO Ro5 spo oe ease odaeeosesbensasd becosoce
seebachi Walcott.............---.-
socialis von Seebach..........-----
uplandica Wiman-.......-.-..-.-.-
uplandica limGensis (Wiman)..
sp. undt. Westergard. ......
Orbiculoidea contraria (Barrande).
pileolus (Salter)..-.............-...-
varians (Barrande)..-.-..-..---.---------
Nisusia? vaticina (de Verneuil and Barrande).
Nisusia (Jamesella) kuthani (Pompeckj)..-..
pellico (de Verneuil and Barrande)..
perpasta (Pompeckj).........-..----
perpasta macra (Pompeckj).........-
erpasta subquadrata (Pompeckj)-. -
Protorthis? hunnebergensis Walcott.....
Billingsella exporrecta (Linnarsson) ....-
exporrecta rugosicostata Walcott. .
hicksi (Davidson)...-.-..--.------
lindstromi (Linnarsson)....-..-.---
romingeri (Barrande)....-....2.---+..------------- aS
Orusia lenticularis (Wahlenberg).--........--.---------

Eoorthis bavarica (Barrande).....-.---.---------------
christianiee (Kjerulf)..........--------------------
daunus (Walcott)...
primordialis (de Verneuil and Barrande)
tullbergi (Walcott)...........---
wamamni (Walcott): i: 3-5-2. 2--2--- 2-2-2 n cone ceee
Spelindtea CROmpeck))peeeesmes esses ses -eee eee
Spend tab) Geom peck))sseees-se sees eee eee

Eostrophomena elegantula (Walcott) ...........-.---.-

Ordovician.

North and
America.

North America,

cpeig

an

ae Boe Also occurs in—
4) ire
gal.

South

ASIATIC SPECIES.

Geographic distribution of Asiatic species of Cambrian Brachiopoda.

China.

India.

Siberia.

Found also in—

Micromitra (Paterina) labradorica orientalis (Walcott).....-.-.
Micromitra (Iphidella) pannula ophirensis (Walcott)....-..-.--
Opbolus)chinensis\(Walcott) a2 25225 esses eS ee
Tay TAEI NE MEN SO iteoocoogmapmecosecascan= cob seconesesaneure
WAITS) WAN COM ooseéscosseadoonsesossencnacecos + osecadone

MSpwUnd tate Kayser mserestmecmcmsectmcen = seeaneceamenines
Obolus (Westonia) blackwelderi Walcott........-....-.--------
Fo, WinGlit, B NECN. 5 ase con sscooenace ab one vesetonobeeSeenS
Lingulella damesi (Walcott) - yeas
davisi (McCoy)...-...-- Bose
THUCHSIBHECL Che te eee eee eae nets eeeteociciee see aetna
KATITEMSIS| QWiSAZCM)) peisem eas em eee eee eee nee eerie are
WEMOTTAO KT IRAN. oe cosademoaese coseeesenaescoccosasaanes
Lingulella (Lingulepis) eros Walcott............--.------------
os Weatelis (WV/BMCO NN) = coceoscesoes cesses sos] SeoSnqq=Ees=70s
INeobolusiwanthiawaarenbessenee semen anmee eee se cee ee amen aes
Dicellomus parvus Walcott............--.---------------------
Kutorgina cingulata (Billings).......-..-.......---------------
Obolella asiatica Walcott..2....--.--.----.---------------------
Botsfordia granulata (Redlich).........-...-...----------------
Schizopholis rugosa Waagen.
Yorkia? orientalis Walcott... -..---
Acrothele matthewi eryx Walcott. ..-.
?minuta Walcott.-......-...---.-.---

=a

KKXKKK KKK KKK

North America.

North Ametica.

North America.

Europe, North America, and South America.

CAMBRIAN BRACHIOPODA.

Geographic distribution of Asiatic species of Cambrian Brachiopoda—Continued.

China. India. Siberia.

Found also in—

“Atcroweta lisani) Walcott=2: === sss seeeeses-eee
pacifica Walcott.....2.-22..22!
shantungensis Walcott

Discinopsis? sulcatus Walcott

Billingsella pumpellyi Walcott
Tichthofeni Wialcott. = 22222222222

Wynnia warthi (Waagen)..-._..___-

Hoorthis agreste (Walcott)
CLORISK Well Cott) eeeeerye oe eee
kayseri (Walcott)
kichouensis (Walcott)
linnarssoni (Kayser)
pagoda (Walcott) -..
sp. undt. Walcott

Syntrophia orthia Walcott

Huenella orientalis (Walcott)

KXKXKKKK

KXKKKKK KX

SOUTH AMERICAN SPECIES.

South American species of Cambrian Brachiopoda.

Obolus sp. undt. e Kayser @
Lingulella davisi (McCoy)
ferruginea Salter

Orusia lenticularis (Wahlenberg)

Koorthis saltensis (Kayser) @

Micromitra (Paterina) etheridgei (Tate)

Kutorgina peculiaris (Tate) -

AUSTRALIAN SPECIES.

Australian species of Cambrian Brachiopoda.

Argentina.
Do.
Do.

South Australia.

Do.
Do.

Obolella wirrialpensis Etheridge

Nisusia compta (Tate)
Hoorthis tatei (Etheridge)

Huenella etheridgei Walcott

ORDOVICIAN BRACHIOPODA.

NORTH AMERICAN SPECIES.

Geographic distribution of North American species of Ordovician Brachiopoda.

General location.

Occurrence in Cambrian.

Obolus anceps Walcott
belli (Billings)... -
eyane (Billings)
discoideus (Hall and Whitfield)
dolatus (Sardeson)........--.--------.-
miatinalis (Hall)

Hanurraryi Bilin gs ess Se a ee eae RR Seay See ere ae Sacre
rotundatus (Walcott).

chusetts.
spissus (Billings)..-.-.-.....----.- d
Obolus (Westonia) elongatus Walcott.
ip his sVWWalcottee Meee shee eae aoe eee
notchensis Walcott. a
TOgEeTSIAWalCcOth Avo vo see ve cstns ae see ee sue ou ee eee eee e ates SRE epee e aoe ee Massachusetts, Rhode
Island, and Newfound-
land.
Mingilellaybellar@Walcoth) passsesnciseecee ene ease e eens ei eee eerie ee eee es Newloundiand and Rhode
sland.
desiderata/((Wialcott) ss: <sees= sec ate ee se ooo Se Se Sag He eid ctc a sor a et ete ede Coloradoeeseeeee seat eee
GUST ONPIGID) se code scebeseonasubaceoeses Quebec.........-.-
grandis (Matthew)....-..----------------- .-| New Brunswick....
Holey @Billin gs) Ses ee ee ee ee ence neces .| Newfoundland.....
irenel@Billin'es) eee seen eee cece ee Quebec ae
manticulai@Wihite)). .22-222--2-22-.22.2------ Nevadaa: eines ae
. mosia (Hall) Minnesota...........--
Lingulella (Lingulepis) acuminata (Conrad) ee SYOLIESS Soe =e eee
Fd 0} sane eee eee

acuminata sequens Walcott
aldentified from South America only.

C.

B, C, D2, D4, Ds, and D7, and
China.

B and C.

B, C, Ds, and D?,

C.
D2.
B, C, D1, D2, D4, Ds, and D7.

b See table on pp. 114-119.

DETAILED STRATIGRAPHIC DISTRIBUTION. 123

Geographic distribution of North American species of Ordovician Brachiopoda—OContinued.

General location. Occurrence in Cambrian.a
Tania aM ISD (MV ALCOUL) settee So ek ooo a2 eee ae Be eriow = cise =e cs seme eee eee oes ING Vad aan ace seek. ne ore
esideratay Gb illinos) eet e eer oo ecicc sons $a BAS eee moe aee coe eeee Quebec...
Take, (BUDS) yi S8S53 | oR AS RHEE eae ese ae aie See IER iene ya ayes eythane LO OE ae os Samara
Dicellomus nanus (Meek and Hayden)................--.-------------------- WA MAE so oo ecooescasce C, D3, and D7.
SchizambonkmanitouensisiwWialcott)--- .. 252222222) Ge eis ee co-|| COHN Ws sacenesdabssedoseace
EVD IGALISRVVal CO UUM map seaiset moe > ce acc io <e Sens case eae ee om acne eee ...| Nevada... eee | Cs
eA\crotiheledevasensisWialcOth.2o- 22-5 s\j-2 25 o2cm nese ne noe eooe cesiscenmere access ...| Quebee
JOROUICSES (CIBSBUMIMVES)) = =o co Stes ang gee SeGE eee Ee te eee nore nn Emmteeeieas Soar ..-| Quebec and New York.....-
Linnarssonella minuta (Hall and Whitfield) ......................-....-...-.- DEA NGvad aacee teak cence ees (OF
PACTOLLeLa Pema Ulm OS ee te 2 sce. sbajnn as soa gteee eben en Geeeeleene Ee Newioundlands 5552s ae
Han OeNSiSMW aleo thee nh cetis is dp Soc es ateeceeec cee eeltoey See cet setaaterree PEE INIGN Cb ee secomaee see ate a 6 Cand D7.
ON PLES) WWECO IRS SS OA ES mene ae ete eee mare? Ly se rae ent et -..| Quebec..-..-
Billinesellarcoloradoensis! (Shumard) ss. 2 522 322832 ..-| Minnesota -- A,C, D2, D3, D5,and D7.
CHEE (Mal Cott) Berean ioe oat cic ccsciscse scic- once cae tices eect en ese ces pee Viermontyss- Goes St hee
Eoorthis desmopleura (Meek) Swe BRAD aes See ..-| Colorado and Utah.......-.- B, C,.D6, and D7.
desmopleura nympha (W Aes Ts
wichitaensis (Walcott). - SSdOns hc C, D3, D4, D®, and D7.
Syntrophia calcifera (Billing: Quebec an
lateralis (Whitfield)... ... Vermont. .
nundina Walcott......- .| Nevada, Utah, .| C.
Clarkella montanensis (Walcott) “| Montana s (a 22 sae eae

a See table on pp. 114-119.

EUROPEAN SPECIES.

Geographic distribution of European species of Ordovician Brachiopoda.

General location. Also occurs in—
Mol boribiamecuivan(utorga) eet sce ena -0 ce Shaan se sete ete neae aoa weber banseaeere s IRMssiaees erat asec racers
SO DolustediyenuspBanran deen sss ec se cents ee sere Seeete nate ee mner ay veya aes ns S| Bobemiate ste essere se eee

ancillas) (BarranGe) eee =he .ai--2 oss oss ee oid oe See otees oe Sete ae See eee cee sens On ae Bere S see senses
complexus Barrande. . as
feistmanteli (Barrande
? mirandus (Barrande) -
? rokitzanensis Barrande.. --
Obolus? (Westonia?) lamellosus (

Lingulella davidsoni (Barrande) ..do aa

davisi (McCoy)..--.--.---- Bebe lam de seen eee eee Upper Cambrian.

ihe bertips anrois seas - ek Se sess pace e es He aa cade ss eeele Soc Seales « ceeeacie esos 182 | Gpainwe neal sue wee ee

inSOns GB arran de) seer sat ace aoe oa ae nin ae toalece me tiated cece oem eee see Row PB ONEeMIAL mee sacs pecan ee

Simp lexe GB ALTA dO) Macesae a seine mn ectca ees stan ase ce oom ees Senos samen oe Nee sees (Wane seduce se soseeneees
Miphonotreraineuicilatal (Bichwald) es sesss ss. 26s e= eee eee ee eee eee Hussey and East and West | Passage beds (Russia).

russia.

SV ETNIICOSay GHICLIW AG) Seen Seine Saree ea Bens Scgieiaie Siem red wate eran easier yap eel ieee do Do.
Acrotreta babel Barrande. - - -| Bohemia.

? minima (Barrande).. - Bi eee do

nicholsoni Davidson. --- Scotland and Ireland...-..-. Upper Cambrian.

SUP CONICAMKUITOL Pa ay aoa ser sce as Seine Seen seme cectiseiae ene ccee see any eee JRMSSIB ERs seeeetes eases

DETAILED STRATIGRAPHIC DISTRIBUTION OF CAMBRIAN AND ORDOVICIAN
BRACHIOPODA.

The following table includes, arranged alphabetically by States or countries, more or less
detailed information concerning the stratigraphic distribution of the different species of Cam-
brian and Ordovician Brachiopoda.

The data available for the foreign species were not sufficient to warrant greater detail
than that secured by the use of generalized sections, and there has been no attempt to keep
the species from any one section in a distmet column. Doubtful correlations are indicated
by a question mark after the locality number.

For some of the regions in North America typical fossiliferous sections have been intro-
duced, giving in an adjoining column the species collected from the various horizons in the
section and in a third column the species collected at other places in the same general area.
In such tables the stratigraphic arrangement of the second column is fairly accurate; that of
the third may contain errors in correlation and must be regarded as merely approximate.
Each specific name is followed by the number of the locality at which it occurs, and the list
of localities on pages 161-291 will furnish the student with all known information as to the
association and the stratigraphic and geographic position of the species in question.

The numbers of the different localities identified from a given formation, State, country,

or place may be found by referring to the index.

124 CAMBRIAN BRACHIOPODA.

Detailed stratigraphic distribution of Cambrian and Ordovician Brachiopoda.@

Alabama.

See Tennessee, Georgia, and Alabama, where the horizons are more or less closely differentiated and correlated,
with complete lists of localities and included species.

Alberta.

See British Columbia: Mount Bosworth section, where the Alberta localities are shown in their approximate
stratigraphic position.
Arizona.

One of the Arizona localities (75) has been assigned to the Upper Cambrian; 74b occurs high up in the Tonto
group, but has been entered as Middle Cambrian; and the remainder (see index for numbers) occur at various more
or less closely related horizons in the “‘Tonto” sandstone.

Bohemia.

Section. Localities and species.

itagetddae ees 7k eee ere a cine Uh ase aa e eer mn etn 303m, 303n, 30380.
Lingulella davidsoni—303m, 303n, 3030.

Mitage, da vem eee acre aee sens A Oech dau Aware’ 308, 303a, 303p.
Lingulella? simplex—303a, 303p.
Acrotreta babel—303, 303a.

By Cape dei os Pacer eee ciceates cia ge osetia te eases 308b, 303d, 3038e, 303¢-1.

Obolus? advenus—303d.

Obolus? ancillus—303¢g.

Obolus? complexus—303¢, 303h, 303i.
Obolus feistmantcli—303i, 303}.
Obolus mirandus—303k.

Obolus rokitzanensis—303b.

Obolus? (Westonia?) lamellosus—3031.
Lingulella insons—303d, 303e.
Lingula? eximia—3031.

Acrotreta? minima 303d.

PASSAGE BEDS.
308¢, 303f.

Obolus bavaricus—303c.

Obolus minor—303c.

Obolus palliatus—303c.

Lingulella cedens—303c, 303f.

Lingulella humillima—s303c, 303f.

Lingulelia signata—303e.

Lingulella wirthi—3038e, 303f.

Lingula n. sp.—s03f.

Acrotreta inchoans—303c, 303f.

Acrotreta nD. sp.—s03f.

Orbiculoidea contraria—303c, 3038.

Orbiculoidea varians—303c, 303f.

Hoorthis bavarica—303¢, 303f.

(See 303f, p. 235, for associated forms other than brachiopods.)

MIDDLE CAMBRIAN.

Etage C (see Paradozides zone)-........-------------------- 345b?, 345c, 345f, 345¢, 345h, 3451.

Acrothele bohemica—345b, 345c.

Nisusia (Jamesella) kuthani—34at.

Billingsella romingeri—345c, 345f, 345g, 345h, and 3451.

Paradoxides zone (see Etage C)..-...............-..--.---.- 345, 345a, 345d, 345e.

Lingulella ef. ferruginea—345.
Acrothele bohemica—345, 345a.
Acrothele quadrilineata—345d.
Billingsella romingeri—345.

Eoorthis sp. undt. a—345.

Eoorthis sp. undt. b—345e.

(See 345, p. 270, for additional forms.)

LOWER CAMBRIAN.

Conglomerate zone of the Kamenn4 hiirka.................. 3451, 345j, 345k?. a

Nisusia (Jamesella) kuthani—345i, 345j, 345k.
Nisusia (Jamesella) perpasta—3451, 345), 335k.
Nisusia (Jamesella) perpasta macra—345i, 345}.
Nisusia (Jamesella) perpasta subquadrata—345i, 345).

a¥or complete lists of the localities in each State, country, formation, etc., see index.

DETAILED STRATIGRAPHIC DISTRIBUTION

125

Detailed stratigraphic distribution of Cambrian and Ordovician Brachiopoda—Continued.

British Columbia: Mount Bosworth.

Mount Bosworth section.
[ Walcott, 1908f, pp. 204-217.]

Localities and species in the
Mount Bosworth section.

Other localities and species In
British Columbia and Alberta
shown in their approximate
stratigraphic position.

The Mount Bosworth section is exposed north of Hector, British Columbia,
on the Continental Divide north of the Canadian Pacific Railway.

The general dip of the strata is to the northwest 20°; strike, N. 30° E.

The section is continuous except for the displacement between the Paget and
Bosworth formations of the Upper Cambrian. That this does notcut out any con-
siderable thickness of strata is proved by the unbroken section in the cliffs of
Mount Daly 3 miles to the north. Only the upper part of the St. Piran sand-
stone is exposed on Mount Bosworth; the remainder of the section shown on
pages 131 and 132 was measured in the vicinity of lakes Louise and Agnes, nearly
5 miles to the southeast.

The summit of the section is on the west spur (Sherbrooke ridge) of Mount
Bosworth overlooking Sherbrooke Lake. The highest beds are on the south sum-
mit of the ridge, and from their lithologic character and the presence of
obscure fossils that suggest Ophileta of the Lower Ordovician the upper 110 feet
of strata is tentatively referred to the Ordovician system.e The strata near
the summit are much broken up owing to a fault line that crosses the ridge.

ORDOVICIAN.@

1. Massive-bedded gray and bluish-gray arenaceous limestone, with Feet.
thin layers, irregular stringers, and nodules of dark chert-.--.. 110
UPPER CAMBRIAN.
Sherbrooke limestone [ Walcott, 1908a, p. 2]: Annelid borings and trails.
1. Massive-bedded bluish-gray limestone, with some cherty matter in Fragments of undetermi-
the form of small nodules and stringers; also irregular partings nable trilobites.
and fillings of annelid borings by gray dolomitic limestone,
Wweacheninpabutiee oe ssn et Fee US ee eae eke ee ee en 175
2a. Gray oolitic limestone in thick layers, with bluish banded Crepicephalus.
limestone intercalated at irregular intervals. The banded Pterocephalia ?.
appearance of the nonoolitic layers is owing to the bufi- Ptychoparia.
weathering of the thin dolomitic layers..............----- 190
2b. Greenish-drab and gray siliceous shales with interbedded 57d, 58f.
oolitic limestone in bands of layers from 6 inches to 4 feet In green shales near sum-
thick; also a few bands of thick-bedded bluish-gray lime- mit:
Stone that breaks up into shaly limestone on weathering.. 335 Lingulella isse—57d.
In oolitic layers:
Agnostus sp. undt.
Tllznurus.
Ptychoparia.
In limestone:
Obolus sp.—si.
2c. Gray oolitie limestone with thin bands of interbedded Menurus.
shaly blue-gray limestone. Gray dolomitic buff-weather- Agnostus.
ing flattened nodules, stringers, and thin layers of lime- Ptychoparia.
stone occur in a very irregular manner..._..-...---.-.--- 65 a Bathyurus-like pygidia.
— 590
3. Arenaceous dolomitic steel-gray limestone, weathering light gray
and buff way SSS HRA ARS Ee Ieee Ge EE Ce erm nore phe es 610
The line of demarcation between 3 and the bluish-gray lime-
stones below is irregular. The gray beds of 3 extend along
the cliff and abruptly change to bluish gray. In the upper
100 feet of 3 irregular masses of bluish-gray limestone occur
like great lentiles, as though they were cores left in the
general alteration (dolomitization) of the strata.
Motallon Sherbrooke limestone nesses se see ease es eeeeee= ae eee i By(5)
Paget limestone [ Walcott, 1908a, p. 3]:
1. Massive-bedded dark bluish-gray limestone forming base of cliff
on the west side of the amphitheater on the west slope of Mount
Bosworth and, with 3 of Sherbrooke limestone, the upper cliffs
ofvPagetheakvand MountaDaly2eeeeeeeeee ne season nee ee cee 60
2. Massive beds of oolitic limestone with irregular interbedded bands Hyolithes.
of green siliceous shale. Thin layers, irregular stringers, and A gnostus.
nodules of gray bufi-weathering dolomite occur in the oolitic Crepicephalus.
Itt SS ONES Se Seas 5 ae Sse ADS OS Seago Ones asqcidie SUS EM SAMOS becoae 300+
Base covered by talus slope on line of the section. It is well ex-
posed on the southeast face of Mount Daly and Paget Peak.
‘The thickness is placed at 300 feet, which I think is less than
the total thickness. Over 200 feet was measured.
MotaliofPacet limestone: =.=. =.= -eeee == oie sesee esses 360+

a During the field season of 1911 these beds were examined by Mr. J. A. Allanand Mr. L. D. Burling, who found, in the uppermost portion,

fossils similar to those in 2b of the Sherbrooke limestone.

This made it possible to place between the new Sherbrooke and the true Ordovician

a series of nearly 4,000 feet of Upper Cambrian shales and limestones referred by Mr. Allan to the Chancellor end Ottertail formations, respec-

tively.

(See Walcott, 1912, Smithsonian Miscellaneous Collections, vol. 57, No. 7, pp. 229-231.)

126

CAMBRIAN BRACHIOPODA.

Detailed stratigraphic distribution of Cambrian and Ordovician Brachiopoda—Continued.

British Columbia: Mount Bosworth—Continued.

Mount Bosworth section.
| Walcott, 1908f, pp. 204-217.]

Localities and species in the
Mount Bosworth section.

Other localities and species in

British Columbia and Alberta
shown in their approximate
stratigraphic position.

UPPER CAMBRIAN—Ccontinued.

Bosworth formation [Walcott, 1908a, p. 3]:
1. Massive-bedded gray and bluish-gray arenaceous dolomitic lime-

stone. Several bands of steel-gray, yellowish buff-weathering Feet.
bands of strata occur in the lower half of 1...-.-....-.-.------- 600-++
This formation forms the base of the high cliffs on the southeast
face of Mount Daly and Paget Peak.
The lower portion of 1 was measured and the upper parts esti-
mated. ‘The thickness given is probably 100 feet or more less
than the actual thickness.
2a. Shaly and thin-bedded gray and dove-colored, compact, fine-
grained dolomitic limestone weathering buff and light gray.
Thicker layers occur in bands from 1 to 6 feet thick...-...- 422
2b. Greenish siliceous shale with thin interbedded layers of sili- At about this horizon in the Cas-
ceous, compact, gray limestone...........- Mos sseee seat oe 48 tle Mountain section, 20 miles
southeast of Mount Bosworth,
small trilobite heads of the
genera Ptychoparia and Soleno-
pleura occur in a band of gray
and bluish-black limestone,
and, just below, fragments of
a species of Obolus.
2g Iba OMS HMI BWP WO) Wie conocasccmsseousscasonosceoecesecees 517
== 987
3. Variable arenaceous shales with alternating bands of color—green-
ish}. deep red butt, yellow. andieraye sees see ee 268
Numerous mud cracks and ripple-marks occur on many of the
layers. ut
Total of Bosworth formation..........-..--..-.------------- 1, 855++
MotalkWip perm Cam) bn ane ees sees ee see eee eee eee ee 3, 590-4 |
MIDDLE CAMBRIAN.
Eldon limestone [Walcott, 1908a, p. 3]:
la. Irregularly bedded gray siliceous and arenaceous limestone in 192 feet above the base:
thick layers above and thin layers below; at 192 feet from the Agnostus sp.
base a bed of bluish-black limestone is fossiliferous. Above Ptychoparia, 2 species.
the fossiliferous bed the strata become more massive, arena- Bathyuriscus-like pygid-
ceous, steel gray in color, and weather to a light gray........ 410 ium.
1b. Light and dark gray thin-bedded arenaceous limestone weath-
ering Tigh tenaiy sy ere eepiewei tin de. aati als aro pa Seely 110
1c. Massive-bedded siliceous, fine-grained, compact, dark bluish-gray Near the summit:
limestomece 325 hes See eae eee 197 Billingsella?
Two yellowish buff-weathering bands of limestone 2 to 3 feet Neolenus-like pygidium.
thick stand out in color on the face of cliffs.
1d. Massive-bedded limestone much like that of Ic................. 71
— __—*788

2. Thin-bedded bluish-gray limestone with irregular layers and stringers
of gray bufl-weathering dolomitic limestone....................- : 95
At 24 feet from the base a shaly bluish-gray siliceous limestone about
2 feet thick is interbedded.

35e.
In shaly limestone:
Obolus mceconnelli var.—
30g.
Obolus membranaceus—
35g.
Tsoxys ef. argentea—35g.

Ptychoparia, 3 species—35g.

So cUseRoedSoteoor in 190

3. Massive-bedded dark-gray arenaceous limestone

a This formation reminds me, in lithologic character and appearance, of strata of the upper portions of the Algonkian Belt seriesof Montana. No
traces of life were observed and the shaly, bandéd character of the beds is very striking.

DETAILED STRATIGRAPHIC DISTRIBUTION. 127

Detailed stratigraphic distribution of Cambrian and Ordovician Brachiopoda—Continued.

British Columbia: Mount Bosworth—Continued.

|

Other localities and species in
Mount Bosworth section. Localities and species in the British Columbia and Alberta

[Walcott, 1908f, pp. 204-217.] Mount Bosworth section. shown in their approximate

stratigraphic position.

MIDDLE CAMBRIAN—Continued.

Eldon limestone—Continued.

4, Massive-bedded cliff-forming light-gray arenaceous limestone. At 57n.
several horizons bands of thinner layers from a few feet up to 30 In the Mount Stephen section,
feet in thickness occur. One of these 480 feet from the base forms Jeet. 7 miles southwest of Mount
BSH SN GHerrACe Meer mel sc cticiee secs Seas <-ceie oie Coke eee 1, 655 Bosworth, at a horizon about

700 feet above the base of this

limestone, the following fossils

have been recognized :
Protospongia (spicules)—57n.
Lingulella cf. isse—d7n.
Hyolithes sp.—57n.
Agnostus cf. montis—57n.
Zacanthoides spinosus—57n.
Ptychoparia sp.—d7n.
Bathyuriscus sp.—d7n.
Ogygopsis sp.—s7n.

otakomeldonimestonessnaeaescee neces ese eee ee eee eee ee 2,728
Stephen formation [Walcott, 1908a, p. 3): 57e, 57k. 35k,@ 57f, 57j, 58i, 58j, 58r, 58w.
1. Thin-bedded dark-gray and bluish-black limestone.........---.---- 315 | Micromitra zenobia—5ic. Micromitra zenobia—35k.
Obolus meconnelli—a7c¢, 57k. | Micromitra(Paterina) stissingensis
Nisusia alberta var.—o7¢,57k. ora—3ok.
Hyolithes carinatus—i7ce. Micromitra (Iphidella) pannula—
Agnostus sp.—57k. 35k, 57].
Agraulos sp.—s7k. Obolus meconnelli—é7{, 58i, 58],
Menocephalus sp.—dic. 58r, 58w.
Ptychoparia, 3 species—57e, | Acrothele Susidie oe).
57k. Acrotreta depressa—571, 58], 58r.
Neolenus sp.—d7e, 57k. Nisusia alberta—35k, 57}.
Bathyuriscus sp.—si7c. eae (Jamesella) cf. nautes—
it.

(See 35k, 57f, 57j, 58j, and dsr,
pp. 198 and 207-210, for addi-
tional associated forms.)

14s,

At Mount Stephen, about 7 miles
southwest of Mount Bosworth,
a siliceous shale » occurs at the
summit of the Stephen forma-
tion, in which the following
unusually rich fauna occurs:

Hyolithellus flagellum (Mat-
thew) [1899, p. 40].
Hyolithellus annulatus (Mat-

‘| thew) [1899, p. 42].

Orthotheca corrugata Matthew
[1899, p. 42].

Orthotheca major _ Walcott
[1908e, p. 246, Pl. I, fig. 11).

Hyolithes carinatus Matthew
[1899, p. 42].

Hyolithes sp.

Stenotheca wheeleri_ Walcott
[1908¢, p. 245, Pl. I, fig. 7].

Platyceras rominger Walcott

[1889e, p. 442].

Plutyceras bellianus Walcott
[1908e, p. 246, Pl. I, fig. 13].
Acrotreta depressa (Walcott)

[1889e, p. 441].
Micromitra (Iphidella) pan-
nula (White) [1874, p. 6).
Obolus meconnelli (Walcott)
[18s9e, p. 441].

Obolus septalis Walcott
[1905a, p. 331).

Nisusia alberta Walcott [1889c,
Pp. 442).

Phithedra columbiana (Wal-
Cott) [1889c, p. 441].

Scenella varians Walcott
[1886b, p. 127].

a This is the locality containing the beautifully preserved annelids, medusz, holothurians, crustaceans, etc., now being described and illus-
trated in volume 57 of the Smithsonian Misceilaneous Collections.

b Thename Ogygopsis zone is applied to the local development of arenaceous and calcareous shale at the summit of the Stephen formation on the
northwestslope of Mount Stephen. Theshale band (lentile) has a maximum thickness of about 150 feet. It thins out to the northeast and is faulted
outtothesouthwest. Atits maximum thickness, 2,800 feet above Field, it carries immense numbers of trilobites, especially Ogygopsis klotzi (Rom-
inger), Bathyuriscus rotundatus (Rominger), Neolenus serratus (Rominger), Zacanthoides spinosus (Walcott), and, in addition, sponges, cystids,
brachiopods, pteropods, and gastropods. The shale is less rich in fossils one-fourth mile northeast on the strike; also to the northwest. Lentiles
of gray quartzitic sandstone and siliceous gray limestone occur in the shale, and the entire band appears to be a lentile between the thin-bedded blue
limestones and the superjacent massive arenaceous limestone formation. There is no trace of the Ogygopsis zone at the same horizon on Castle
Mountain 20 miles east-southeast. On Mount Field it is represented by the Burgess shale, Locality 35k.

There is a sharp anticline, with a northeast-southwest axis, in the shale and the thin-bedded limestones beneath, on the northwest slope of
Mount Stephen. The southeast limb is crushed and the beds are largely faulted out against the massive arenaceous limestone before reaching the
amphitheater at the head of Field Brook. On the northwest limb the shales are unaltered and slope down the side of the mountain for 1,800 feet,
thus affording a great exposure of the shale and contained fossils.

128

CAMBRIAN BRACHIOPODA.

Detailed stratigraphic distribution of Cambrian and Ordovician Brachiopoda—Continued.

British Columbia: Mount Bosworth—Continued.

Mount Bosworth section.
[ Walcott, 1908f, pp. 204-217.]

Localities and species in the
Mount Bosworth section.

Other localities and species in
British Columbia and Alberta
shown in their approximate
stratigraphic position.

MIDDLE CAMBRIAN—Continued.

Stephen formation—Continued.

14s—Continued.

Anomalocaris canadensis
Whiteaves [1892, p. 207).
Anomalocaris? whiteavesi Wal-
cott [1908c, p. 246, Pl. II,

figs. 2, 2a, 4, 6, and 6a].

Anomalocaris?? acutangula
Waleott [1908c, p. 247, Pl.
TI, fig. 5).

Agnostus montis Matthew
{1899, p. 43].

Dorypuge (Kootenia) dawsoni
(Walcott) [1889c, p. 446].
Bathyuriscus rotundatus
(Rominger) [1887, p. 16].
Bathyuriscus pupa Matthew
[1899, p. 51) probably=

Bathyuriscus occidentalis.

Bathyuriscus occidentalis
(Matthew) [1899, p. 49].

Bathyuriscus ornatus Walcott
[1908b, p. 39].

Karlia stephenensis Walcott
[1889e, p. 445).

Corynerochus romingeri Mat-
thew [1899, p. 47]=Karlia
stephenensis.

Neolenus serratus (Rominger)
[1887, p. 13].

Neolenus granulatus Matthew
[1899, p. 55]= Neolenus ser-
Tatus.

Ogygopsis klotzi (Rominger)
(1887, p. 12].

Oryctocephalws reynoldsi
Reed [1899, p. 359].

Oryctocephalus walkeri Mat-
thew [1899]= Oryctocephalus
reynoldsi. ‘

Burlingia hectori Walcott
[1908b, p. 15).

Ptychoparia cordillere (Rom-
inger) [1887, p. 17].

Conocephalites cf. perseus
Hall, Matthew [1899, p. 46]
= Ptychoparia cordillerz.

Ptychoparia palliseri Walcott
[1908e, p. 247, Pl. III, fig. 6).

Zacanthoides spinosus (Wal-
cott) [1884, p. 63].

Feet. 5i7y.
20-1 Greenishisiliceousishale= smsaseer sees ceesee ance eases 23 Obolus (Westonia) ella?—d7y.
58z.
2b. Thick-bedded bluish-gray limestone, breaking up into thin Micromitra zenobia—58z.
layers 3 to 3 inches thick on weathering..............-.----- 22 Nisusia alberta var.—58z.
Menocephalus—58z.
Ptychoparia—58z.
Neolenus—58z.
2enGreenishisiliceous|shales n= =e eee eee see essen ee es ae eeee eee 70
57g. 58 1.
2d. Alternating bluish-gray bedded compact limestone, siliceous Cruziana. On Mount Stephen, at a horizon
and arenaceous shale, mostly shale below..-.-....--.----.-- 210 Micromitra (Iphidella) pan- 150 feet from the base of this
a 325 nula—57g. limestone, the fauna includes:
Obolus ( Westonia) ella—57g. Micromitra zenobia—b8 1.
Motaliof Stephen formations +---2- ne. se ee eee eee ese ee eee see 640 | Hyolithes—57g. Lingulelia desiderata—58 1.

Leperditia—57g.
Plychoparia—57g.
Bathyuriscus—57g.

Billingsella marion—58 1.
Hyolithes—8 1.
Microdiscus—58 1.
Ptychoparia—s8 1.

Cathedral limestone [ Walcott, 1908a, p. 4]:
la. Vhin-bedded gray to lead-gray arenaceous limestones, weathering
[OoUaT TEN HO Chwilio oss ocoosacesaeesSesccsansaecerc nse
1b. Massive-bedded steel-gray weathering light-gray arenaceous lime-
stone. In some localities thinner layers appear at various hori-
zons and large lentiles of dark lead-gray colored beds occur very
ALTOS UAT Ye se ee es oe eee eee re eey ne oir

404

- DETAILED STRATIGRAPHIC DISTRIBUTION. 129

Detailed stratigraphic distribution of Cambrian and Ordovician Brachiopoda—Continued.

British Columbia: Mount Bosworth—Continued.

Mount Bosworth section.
[Walcott, 1908f, pp. 204-217.]

Localities and species in the
Mount Bosworth section.

Other localities and species in
British Columbia and Alberta
shown in their approximate
stratigraphic position.

MIDDLE CAMBRIAN—Continued.

Cathedral limestone—Continued.

1c. Similar to la. Amnnelid borings and trails occur in and on some of eet.
the layers 126
1d. Similar to 1b 83
le. Thin-bedded lead-gray to blue-gray thin-bedded (layers 1 inch to
4 inches thick) arenaceous limestone..............-...-.--.----- 25
if. Alternating thin and massive bedded arenaceous steel-gray lime-
stone weathering light gray...............-------2----2222-e2e-- 275
1,595
MotaleMiddle\Cambrian se) cee s socio yacieis eels os noel onetime oa 4,963
TOWER CAMBRIAN.
Mount Whyte formation [Walcott, 1908a, p. 4]:
The line between the Middle and Lower Cambrian is placed
at this horizon on account of the presence in the Mount
Stephen section of Olenellus in the limestone 116 feet below
the massive arenaceous limestone belt represented by 1f in
the Cathedral limestone of the Mount Bosworth section.
la. Thin-bedded bluish-gray slightly arenaceous limestone- - ...- 120 Numerous annelid trails and
borings.
57s. 57m, 58k, 58p, 58t.
1b. Gray oolitic limestone in layers 3 to 6 inches thick.........-. 44 Acrotreta sagittalis taconica—| In the Mount Stephen section the
57s. following species occur at a
Nisusia (Jamesella) lowi— horizon near the top of this
57s. limestone (58k and 58p):
Microdiscus sp. undt.—57s. Acrotreta sagittalis taconica—
Agraulos sp.—sis. 58k.
Ptychoparia sp.—7s. Nisusia alberta var.—58k,58p.
Nisusia (Jamesella) lowi—
58k, 58p.
Stenotheca elongata var.—
58k.
Scenella varians—58k.
Platyceras n. sp.—58k.
Hyolithes billingsi—58k, 58p.
Ptychoparia sp.—58k, 5Sp
Crepicephalus n. sp.—d8k.
Protypus D. sp.—d8k.
Albertella sp. undt.—58k.
At Castle Mountain Oholus parvus
occurs at about this horizon
(58t).
About 50 feet down in the Mount
Stephen section, in a gray sili-
ceous shale, the following spe-
cies occur (57m):
Cystid plates—57m.
Micromitra (Paterina) sp.
undt.—57m.
Acrotreta sagitialis taconica—
57m.
Nisusia (Jamesella) lowi—
57m.
TIyolithes (fragment )—57m.
Aolithellus cf. micans—57m.
Scenella varians—5im.
Olenellus canadensis—57m.
5ive, 57r, 68s.
1c. Massive layers made up of banded bluish-gray limestone and Agraulos sp. undt. On Mount Stephen, at a horizon
sandstone in layers 4 inch to 2 inches thick...........-.-. 60 near the top of this bed of lime-
— 224 stone, there was found (57e):

62667°—vou 51, pr 1—12-_9

Acrothele colleni—i7e.

Acrotreta sagittalis taconica—
57e.

Scenella varians—57e.

Stenotheca elongata var.—d7e.

A lbertella sp. undt.—57e.

Olenellus canadensis—57e.

Bathyuriscus sp. undt.—57e.

Near the base on Mount Stephen
(57r, 58s):

Micromitra (Paterina) labra-
dorica var.—57r, 58s.

Micromitra (Iphidella) pan-
nula—ir, 58s.

Acrotreta sagittalis taconica—
57r, 58s.

Ptychoparia, 3 species—57r,
58s.

130

CAMBRIAN BRACHIOPODA.

Detailed stratigraphic distribution of Cambrian and Ordovician Brachiopoda—Continued.

British Columbia: Mount Bosworth—Continued.

Mount Bosworth section.
[Walcott, 1908f, pp. 204-217.]

Localities and species in the
Mount Bosworth section.

Other localities and species in
British Columbia and Alberta
shown in their approximate
stratigraphic position.

LOWER CAMBRIAN—Continued.

On Mount Stephen, at this hori-
zon, there were found:
Microdiscus sp. undt.
Olenellus sp. undt.
ments).
Ptychoparia sp. undt.
Protypus sp. undt.

(irag-

35e.

Inthe Lake Agnes section, 5 miles
southeast of Mount Bosworth,
the fauna of about this horizon

includes:
Micromitra (Paterina)
wapta—s35e.

Obolus parvus—s5e.
Hyolithes billingsi—3se.
Olenopsis n. sp.—35e.
Ptychoparia, 3 species.—35e.
Albertella sp. undt.—35e.
Bathyuriscus—s5e.
Olenellus gilberti—35e.

On Mount Stephen, at about the
same horizon, the following
were found:

Hyolithes billingsi.
Scenella varians.
Olenopsis 1. sp.

35f.

At this horizon on Mount
Stephen the following were
found:

Micromitra (Iphidella) pan-
nula—35f.
Kutorgina cingulata—35f. '
Kutorgina sp. undt.—5f.
ot eee sagittalis taconica—
35f.
Nisusia festinata—35f.
Hypolithes billingsi—35f.
Scenella varians—35t.
Protypus nD. sp.—3of.
Agraulos sp. undt.—35f.
Ptychoparia, 3 sp. undt.—35f.
Olenellus canadensis—35t.

60b.
Obolella vermilionensis—60b.
Wanneria gracile—60b.

Mount Whyte formation—Continued. Feet.
2. Gray and brownish-gray sandstone in thin and massive layers. ..- 31 Hyolithes.
Aaqraulos.
35c.
38. Siliceous shale with a few interbedded thin layers of compact hard On the south slope of Mount
gray sandstones=\ (02. oe sone ee meceeee neon mance ce Snecioa cere = - 115 Bosworth two drift blocks
of siliceous shale, supposed
to be from this horizon,
were found, from which
the following species were
collected:
Micromitra (Paterina)
wapta—35e.
Obolus parvus—35e.
Acrothele colleni—35c.
Wimanella simpler—35c.
Agraulos sp.—35c.
Ptychoparia sp.—s5c.
Albertella bosworthi—35c.
Albertella helena—35c.
Bathyuriscus sp. —35c.
35h.
4, Interbedded layers of gray fossiliferous limestone and greenish-gray Nisusia festinata—35h.
Siliceous|SHAleM Ss gees wee eee ere eco eae ieee cee 20 | Scenella varians—35h.
Hyolithellus—35h.
Ptychoparia—35h.
Agraulos—35h.
Protypus 1. sp.—35h.
Olenellus canadensis—35h.
Total of Mount Whyte formation..............--.-.-.------- 390 | Olenellus gilberti—35h.
Bow River group.
St. Piran sandstone [Walcott, 1908a, p. 4]:
1a. Siliceous and arenaceous greenish-colored shales in layers 1 to
3 inches in thickness interbedded in shaly and thin-bedded.
gray and brownish-gray sandstone, with a thick layer of
compact gray sandstone near the top. ...--...-------.--.-- 68
lb. Irregularly bedded brownish, dirty-gray, and occasionally Annelid trails and borings
purplish-colored sandstones, more or less compact and (Scolithus).
quartzitic, in massive and thin layers that break down read- Hyolithes.
ily omislopesse 22s soos Se eee os ae oe eR eee ne eae 310 Olenellus canadensis ?.
Ptychoparia, 2 species.
1c. Massive-bedded compact light-gray and pinkish quartzitic Annelid trails and borings
Sandstonesieeanes oes see cee See tens ee nee Eee 125 (Scolithus).
= 503 Hyolithes.

Olenellus canadensis ?.

In the Lakes Louise and Agnes section, about 5 miles southeast of
Mount Bosworth, the total thickness of the St. Piran sand- .
SUOTICLIS Hehe ale ys eee ne a mate scene ne eee ape eric 2,705
Below the St. Piran the following section occurs:

Lake Louise shale (Walcott, 1908a, p. 5):
Te Compactiorayssiliceous)sh ales snes seems sae aa eee ean

35d.

Annelid trails—35d.

Cruziana—35d .

Micromitra (Iphidella)
louise—35d.

DETAILED STRATIGRAPHIC DISTRIBUTION. 131

Detailed stratigraphic distribution of Cambrian and Ordovician Brachiopoda—Continued.

British Columbia: Mount Bosworth—Continued.

Other localities and species in
British Columbia and Alberta
shown in their approximate
stratigraphic position.

Mount Bosworth section.
[Waleott, 1908f, pp. 204-217.]

Localities and species in the
Mount Bosworth section.

LOWER CAMBRIAN —continued.
Bow River group—Continued.

Fort Mountain sandstone. a

1. Thin and thick layers of gray, quartzitic, brownish weathering, eet.
compact sandstones (estimated)...-...........-..-.-.--------- 600-++
Motaliwower CAM Dials sees. sence seen een ee aoe aes ee acento 3, 800+
Inkl Chyinlod Mal, Semone ondasoceOSeee oar cane Tea be CREE EaESEeMeCSaSC Done 12,353-+

a In 1908[ Walcott, 1908a, p. 5] these quartzitic sandstones were described as the “‘ Fairview formation.’ Asthatname, however, is preoccupied
in American nomenclature, and as the lower part of the formation has since been found exposed at several places on the east side of the Bow River
Valley, it has been decided to apply the name Fort Mountain sandstone to the whole, from the typical exposures on Fort Mountain. The forma-
tion is here composed of 2,700 feet of sandstones similar to the 600 feet of sediments to which the name “‘ Fairview’’ was applied, and a basal bed of

massive conglomerate nearly 200 feet thick. At this locality the Fort Mountain formation is unconformably underlain by pre-Cambrian rocks.

California.

See Nevada, Barrel Spring section, where the California localities are shown in their approximate stratigraphic

position.

Cape Breton and New Brunswick.

For the strata above the Etcheminian a generalized section only has been used. The Cape Breton localities have,

however, been kept distinct from those in the vicinity of St. John.

collections from Cape Breton.

The Acadian is not represented in the brachiopod
The Etcheminian is so well developed and so fossiliferous on Dugald Brook that

Matthew’s section is copied and the fossils from the brook are kept separate from those occurring elsewhere.

Section.

Localities and species occurring in Cape Breton
arranged in their approximate stratigraphic
position.

Localities and species occurring in the vicinity of
St. John, New Brunswick, arranged in their
approximate stratigraphic position.

UPPER CAMBRIAN.

Bretonian (Matthew, 1903, pp. 49 and 240):

Division C8c2 (A saphellus zone).

807a.
Lingulella ef. davisi—a07a.
Lingulella ferruginea—307a.
Lingulella cf. lepis—307a.
Acrotreta bisecta—307a.
(See 307a, p. 238, for additional associated forms.)

Division C3c (Dictyonemu zone).

3h, 30-q, 8d, 10c-i, 10k-n, 13h, 160, 307, 372,
372a-e. .

Obolus acadicus—3h.

Obolus refulgens—307, 372e.

Obolus (Brdygeria) salteri—3h,3q, 10¢, 10d,10e,10g,
10i, 101, 10m, 10n, 13h.

Lingulella concinna—3h, 30, 3p, 3q, 8d, 10¢,10e-h,
10i, 101, 10n, 13h, 160, 307, 372, 372a-d.

Lingulella ferruginea—sh, 307.

Acrothcle sp.—l0f, 10h. .~

Acrotreta cf. belti—307.

Acrotreta bisecta—3q, 10c, 10d-g, 101, 10n, 13h.

Acrotreta convera—l0e, 10i.

Schizambon priscus—3q, 10c-i, 10k, 101, 13h, 307,
372e.

Orusia lenticularis—10h.

308.

Obolus refulgens—308.
Lingulelia ferruginea—308.
Schizambon priscus—308.
Acrotreta bisecta—308.
Acrotreta belti ?—308.

Division C3b (Peltura zone).

8n??, 13q, 307e?, 307h?, 307i, 307j?, 325%.
Obolus ( Westonia) escasoni—325.
Lingulella minor—3n.
Lingulella (Lingulepis) exigua—sn.
Acrotreta convera—s3n.
Orusia lenticularis—13q, 307e, 307h-j.
(See 13q, 307i, 307j, and 325, pp. 183, 239, 240,
and 259, for additional associated forms.)

2xt, 301u.

Lingulella ef. lepis—301u.
Spherophthalmus alatus—301u.
Lingulella minor—2x.

Lingulella minor ?—2x.

Lingulella (Lingulepis) starri—2x.

Division C3a (Parabolinag zone).

10r, 325b.

Obolus (Bréggeria) salteri—10r.
Obolus (Palzobolus) bretonensis—10r.
Obolus ( Westonia) escasoni ?—10r.
Lingulella levis grandis—325b.
Lingulella lens—10r.

301e, 301n, 301t, 308a, 308b, 308f.
Lingulella levis—301n.
Lingulelia levis grandis—301t.
Lingulelia cf. lepis—301e.
Orusia lenticularis—308b, 308f.
Orusia lenticularis atrypoides—308b.
Orusia lenticularis lyncioides—308b.
Hoorthis atava—308a.
Eoorthis johannensis—308b.

(See 308b and 308f, p. 239, for additional associ-

ated forms.)

MIDDLE CAMBRIAN.

Johannian [Matthew, 1903, pp. 40 and 240):

Division C2ce.

307b?, 307c, 325a.

Lingulella jlumenis—325a.
Lingulella radula—307b, 307¢.
Lingulella rotundata—325a.
Acrotreta sp. undt.—325a.

301x, 301ly.
Lingulella radula—301x, 301y.

CAMBRIAN BRACHIOPODA.

Detailed stratigraphic distribution of Cambrian and Ordovician Brachiopoda—-Continued.

Cape Breton and New Brunswick—Continued.

Section.

Localities and species occurring in Cape Breton
arranged in their approximate stratigraphic
position.

Localities and species occurring in the vicinity of
St. John, New Brunswick, arranged in their
approximate stratigraphic position.

MIDDLE CAMBRIAN—Continued.

Johannian—Continued.
Division C2b ( Forchhammeri zone).

3i, 10022, 10s?, 10t?, 11z3?, 138i, 18r, 307g.
325c?

Obolus ( Westonia) escasoni?—10o, 11z.

Lingulella cania—3i, 10s.

Lingulella concinna—3i.

Lingulella ferruginea—3i.

Lingulella rotundata—3i, 325c.

Lingulella tumida—13i, 13r.

Lingulella (Lingulepis) exigua—si, 10s, 10t, 11z,
131, 13r, 307g.

Acrothyra proavia—3ai.
(See 10sand 307g, pp. 177 and 238, for additional

associated forms.)

308c.
Lingulella (Lingulepis) starri.—808e.

Division O2a.

307f.
Lingulella (Lingulepis) exigua—s07i.

Acadian [Matthew, 1903, pp. 39 and 240):
Division Cid.

Division Cle.

300, 3011.
Lingulella ferruginea—301 1.
Acrothele matthewt—301 1.
Acrothele prima costata—301 1.
Acrotreta baileyi—300-
Acrotreta misera—301 1.
(See both 300 and 3011, pp. 229 and 231, for
additional associated forms. )

| 2e2, 212, 2m?, 2s, 2t, 3b?, 301g, 301h, 301j,
301k, 301m, 30lw (from 1c2), 301z, 308h
(from 1c1), 308i.

Lingulella ferruginea—21, 2s, 301g, 301h, 301k, 301z.

Acrothele matthewi—2.1, 2s, 3b, 301g, 301h, 301j,
301k, 301w, 301z, 308h.

Acrothele matthew? lata—301g.

Acrothele matthewi multicostata—21, 2s, 2t.

Acrotreta gracia—2s.

Acrotreta misera—2s, 2.

Acrotreta sagittalis—2s.

A crotreta sagittalis magna—21, 2s.

Acrotreta sagittalis transversa—301k.

Discinopsis gulielmi—301g, 301w, 308h.

Billingsella coloradoensis—2s.

Billingsella sp.—2s.

Proforthis billingsi—2e, 21, 3b, 301g, 301j, 501k,
308h, 308i.

Protorthis latourensis—301g, 301w, 308h.

Protorthis quacoensis—3)), 301g, 301m, 301w.

Eoorthis hastingsensis—21, 2s.
(See 301g, 301h, 301k, 301m, 301w, 301z, 308h

and 308i, pp. 230-232 and 239, for additional
associated forms.)

Division C1b5.

301b, 301d, 301f.
Acrothele prima costata—301d, 301f.
Acrotreta sagittalis transversa—301b .

Division Clb4.

Division C1b3.

308d.
Botsfordia pulchra.

2i, 2k, 2u?, 301a, 301c?, 308d, 308g (may belong
with 14).

Lingulella ferruginea ?—2i.

Lingulella martinensis—2i.

Botsfordia pulchra—308d.

Botsfordia sp.—2i.

Acrothele matthewi lata—301a.

Acrothele matthewi prima—301a.

Acrothele prima—2i.

Acrothele prima costata—2i, 2k.

A crotreta gemmula—301a.

Acrotreta sagittalis magna—2i.

Acrotreta sagittalis transversa—2i, 2k, 301c.

Acrotreta sp.—30le. |

Trematobolus kempanum—2u, 308g.

Trematobolus pristinus—2i, 2k.

Protorthis helena—2u.

Protorthis (Loperia) dugaldensis—2u. 3
(See 2k and 30la, pp. 163 and 230, for addi-

tional associated forms. )

aThe Protolenus zone of Matthew in New Brunswick corresponds in large part with the Acadian.

DETAILED STRATIGRAPHIC DISTRIBUTION.

133

Detailed stratigraphic distribution of Cambrian and Ordovician Brachiopoda—Continued.

Cape Breton and New Brunswick—Continued.

Section.

MIDDLE CAMBRIAN—Continued.

Acadian—Continued.
Division C1b2.

Localities and species occurring in Cape Breton
arranged in their approximate stratigraphic
position.

Localities and species occurring in the vicinity of
St. John, New Brunswick, arranged in their
approximate stratigraphic position.

2h, 301, 308d.

Lingulella martinensis—2h.

Acrothele matthewi lata—301.

Acrothele prima—2h.

Acrothele prima costata—2h.

Acrotreta baileyi—301.

A crotreta gemmula—s01.

Acrotreta sagittalis transversa—2h.

Botsfordia pulchra—308d.

Trematobolus insignis—301.

Trematobolus pristinus—2h, 301.

(See 2h and 301, pp. 162 and 229, for additional

associated forms.)

Division Clb1.

2f, 2g, 2y?, 301i, 308e.
Lingulella martinensis—2f, 2g.
Acrothele matthewi—301i.
Acrothele prima—2i.
Acrotreta inflata—2f, 2g.
Acrotreta sagittalis—2¢.
Acrotreta sagittalis transversa—2, 2g.
Botsfordia cxlaii—308e.
Lotsfordia pulchra—2y .
(See 2g, p. 162, for additional associated forms.)

Dugald Brook section.
[Matthew, 1903, pp. 21-25.]

Localities and species occurring in the Dugald
Brook section.

Localities and species occurring elsewhere in Cape
Breton shown in their approximate strati-
graphic position.

Etcheminian:

Division Ef. Feet.
Siliceous gray shale......... 10
Dark-gray rather coarse

Shales a -/e eee oucee asec 32

Dark-gray somewhat sili-
ceous flaggy shales. ......-

18n, 344d.
Lingulella atava—13n, 344d.
Lingulella collicia—344d.
Acrothele avia—13n.
Acrothele proles—13n, 344d.
Acrothyra proavia—344d.
(See 13n and 344d, pp. 182 and 269, for addi-
tional associated forms. )

13m.
Obolus (Palxobolus) bretonensis lens—13m.
Lingulella collicia—13m.
Acrothele avia—13m.
Acrothele avia puteis—13m.
Acrothele proles—13m.
Acrothyra proavia—13m.
(See13m, p. 182, foradditional associated forms. )

Division E3e.
Dark-gray shale, alternately
harder and softer.......-.

Division E3d.
Dark-gray and some pur-
plish-gray shale.........- 30

18n’.
Obolus (Palzobolus) bretonensis lens—13n’.
Lingulella atava—13n’.
Lingulella collicia—13n’.
Lingulella tumida—13n'.
Acrothele avia—13n’.
Acrothyra proavia—l3n’.
(See sa , p- 182, for additional associated spe-
cies. :

344j.
Acrothyra proavia—344j.

18n'’, 344b.
Obolus (Palzobolus) bretonensis—13n"’, 344b.
Lingulella atava—13n"’, 344b.
Acrothele avia—344b.
Acrothyra proavia—13n’', 344b.
(See 18n’’ and 344b, pp. 183 and 268, for addi-
tional associated forms.)

344c,
Obolus (Palzobolus) bretonensis—344c.
Acrothele avia puteis—344e.

Division E38c.
Gray argillaceoussandstone. 25

344a,
Lingulella collicia—344a.
Lingulella sp.—344a.
Acrothele avia—344a.
Acrotreta sp.—344a.
Acrothyra proavia—344a.
(See 344a, p. 268, for additional associated
forms.)

Division E3b.
Fine gray shale......-....-- 25

344,

Obolus (Palzobolus) bretonensis—344.
Lingulella atava—344.

Lingulella sp.—344.

Acrothele avia—344.

Division B3a.
Dark-gray feldspathic sand-
stones, having seams of

gray grit with felsite
Gébrisia ep esescceceeees 50
Gray micaceous shale. .....- 4

181, 131’, 344i.
Obolus (Palzobolus) bretonensis—13 1’, 344i.
Obolus (Palzobolus) bretonensis lens—13 1, 344i.
Lingulella atava—131'.
Acrothele avia—131, 131’, 344i.
Acrothele proles—131, 131’.
Acrothyra proavia—131, 344i.
(See 131’, p. 182, for additional associated forms.)

134

CAMBRIAN BRACHIOPODA.

Detailed stratigraphic distribution of Cambrian and Ordovician Brachiopoda—Continued.

Cape Breton and New Brunswick—Continued.

Dugald Brook section.
[Matthew, 1903, pp. 21-25.]

Localities and species occurring in the Dugald
Brook section.

Localities and species occurring elsewhere in Cape
Breton shown in their approximate strati-
graphic position.

Etcheminian —Continued.
Division E2c.

18e, 3441.
Obolus (Palzobolus) bretonensis lens—l3e.
Acrothyra proavia—l13e.
Acrothyra sera—13e.
Acrothyra signata orta—3441.
(See 13e, p. 181, for additional associated forms. )

Division E2b.
Dark purplish-gray
spathic sandstones........

Division E2a.

Dark purplish-gray feld-
spathic sandstone with
beds of gray quartzite
about the middle.........
Dark purplish-gray feld-

10p, 10q, 3440, 372f.
Obolus (Palzobolus) bretonensis—10p.
Lingulella atava—10p.
Lingulella collicia—10p.
Lingulella triparilis—l0p.
Lingulelia sp.—10p.
Lingulella (Lingulepis) gregwa—l0p.
dengue (Lingulepis) longinervis—l10p, 3440,
722i.
Linguleila (Lingulepis) sp.—l0p.
Acrothele avia—l0p.
Acrotreta gemmula—l0p.
Acrothyra proavia—l0p, 10q.
Acrothyra sera—l0p.
Acrothyra signata—l0p.
Acrothyra signata Oniae LOD:
Protorthis (Loperia) dugaldensis—16p.
(See 10p and 10q, pp. 176 and 177, for addi-
tional associated forms. )

10p’, 10p”. 3
Obolus (Palzobolus) bretonensis—10p’’.
Lingulella (Lingulepis) gregwa—i0p', 10p’’.
Lingulella (Lingulepis) longinervis—10p’, 10p’’.
Acrothele avia—l0p’’.
A crotreta gemmula—10p’’.
Acrothyra sera—10p’, 10p’’.

(See 10p’”, p. 177, for additional associated

forms.

18d, 18d’, 18d’’, 18f, 13g, 13p?, 13p’?.

Obolus (Palzobolus) bretonensis—13d’.

Lingulella (Lingulepis) longinervis—i13d, 13d’’,
13f, 13g, 13p, 13p’.

Lingulella atava—13d'.

Lingulella collicia—13d’.

307d.

Obolus selwyni—307d.

Lingulella atava insule—307d .
Lingulella triparilis—307a .
Lingulella (Lingulepis) roberti—307d.
Acrotreta sp.—307d.

spathie sandstone with Acrothele avia—13d’, 13a”. Billingsella retroflerca—307d.
some slate conglomerate.. 33 Acrothele prima—13d"". > (See 307d, p. 238, for additional associated
Gray fine-grained felsite Acrothyra sera—13d', 13f, 13p, 13p’. forms.)
conglomerate and grit....~ 3 Acrothyra signata—13d’.
— 151 | Acrothyra signata orta—13d"’.
(See 13d and 13g, p. 181, for additional asso-
ciated forms.)
Division Ele. 344h\
Gray shale with seams of Obolus sp.—344h.
Teenish-gray sand and Lingulella triparilis—344h.
lavender-gray shale....... 3 Lingulella cf. tumida—344h.
Lingulella sp.—344h.
Lingulella (Lingulepis) gregwa robusta—344h.
(See 344h, p. 269, for additional associated
forms. )
Division E1d. 18t’’ (Elec and Eid), 344m. 344e, 344n?.
Compact dark-gray sandy Lingulella triparilis—13t’’. Obolus sp.—344e.
shales tisacccs aso Lingulella (Lingulepis) gregwa—i3t'’, 344m. Lingulella cf. collicia—344e.
Lingulella (Lingulepis) gregwa robusta—344m. Lingulella torrentis—344e.
Acrothyra sera—13t’’, 344m. Lingulella (Lingulepis) gregwa—s44e, 344n.
Acrothyra signata—13t’’. Lingulelia (Lingulepis) sp.—344e.
(See 13t’’ and 344m, pp. 183 and 270, for addi- | Acrothyra sera—344e.
tional associated forms.) (See344e, p. 269, for additional associated forms. )
Division Elec. 18t’’ (Elec and E1d), 344g.
Dark-gray shale............ 21 Lingulella triparilis—i3t’’, 344g.

Lingulella (Lingulepis) gregwa—13t"’, 344¢.
Acrothyra sera—18t'’, 344¢.
Acrothyra signata—13t’’, 344g.
(See both 18t’’ and 344g, pp. 183 and 269, for
additional associated forms.)

Division E1b.
Gray quartzites with sand
and clay seamsattop.... 6

18t, 18t’, 344k.
Lingulella triparilis—13t, 13t’’, 344k.
Lingulella tumida—13t.

Shales ? (concealed)........ 10 Lingulella sp.—344k.
Purplish-gray finely crystal- Lingulella (Lingulepis) gregwa?—a44k. e

IAS WHEY: se cbsedsaseooncs 18 Acrothele prima—13t.

Acrothyra signata—13t, 344k.
(See both 13t and 344k, pp. 183 and 270, for
additional associated forms.)
Division Ela.

Soft purplish-red shale..... 18

Dark purplish-gray trap and
ERM <a sagssecesaseans 10
Dark-purple amygdaloid
and bright-red slates... ..-

} ‘
DETAILED STRATIGRAPHIC DISTRIBUTION. ; 135

Detailed stratigraphic distribution of Cambrian and Ordovician Brachiopoda—Continued.

Cape Breton and New Brunswick—Continued.

P an A ae ee iti ie i herein Cape
Dugald Brook section. Localities and species occurring in the Dugald Localities and species occurring elsew ara
9]_95 3 . Breton shown in their approximate strati-
(Matthew, 1903, pp. 21-25.] “ Brook section. graphic position.
Coldbrook [Matthew, 1903, p. 15]. Feet.
JOG IGG 2a os Seo at eee sae ee eee 185
Grays WaleShenme emcee esse oece ae 25 | 13k, 344f.
Micromitra (Iphidella) pannula?—13k.
Obolus torrentis—13k, 344f.
Lingulella cf. triparilis—344t.
Lingulella (Lingulepis) pumila—13k, 344f.
Acrothyra sera—13k, 344f.
Acrothyra signata prima—13k, 344.
(See 344f, p. 269, for additional associated forms. )
Felsitic conglomerate............_.. 100
a
LOWER CAMBRIAN. @

a Fossils from the Lower Cambrian have been identified at: but two localities (8a and 801v), and these are on Hanford Brook, near St. John, New
Brunswick. The Lower Cambrian is not represented in the brachiopod collections from Cape Breton.

Colorado.

Most of the Colorado forms occur in the siliceous beds of the Lower Ordovician. Three localities (360g-i) have
been identified from the Upper Cambrian and two (3g and 360d) from the Middle Cambrian. For the numbers of all
the localities see the index. .

Denmark,

See Sweden, Denmark, Finland, and Norway, where the horizons are more or less closely differentiated and corre-

lated, with complete lists of localities and included species.

England, Scotland, and Wales.

Section. Localities and species.

ORDOVICIAN.

Bala ( Caradoc, Coniston) limestone. 304n, 3660.
Lingulella davisi—304n, 3660.

Llandeilo shales. 316, 316a.
Acrotreta nicholsoni—316, 316a.

Llanvirn.

Arenig.

UPPER CAMBRIAN.

Tremadoc (Shineton, Bronsil, Lower Stockingford?) shales. 304, 304a, 304h, 304i, 304j?, 304k, 3041, 304p, 305, 305a, 305c, 305e-j, 318w, 3866p, 366q.
Obolus (Broggeria) salteri—304a.
Lingulella davisi—366p, 366q.
Lingulella lepis—305a, 305¢, 305e-j, 366q.
Lingulella nicholsoni—304a, 304i, 304k.
Lingula sp.—304a.
Acrothele intermedia —304j
Acrotreta belti—304, 304a, 305.
Acrotreta nicholsoni—304h, 3041.
Acrotreta cf. nicholsoni—304a.
Acrotreta sabrine—304h, 304i, 304j, 304p.
Acrothyra?—304a.
Eoorthis carausii—318w.
(See 304a, p. 236, for additional associated forms.)

Upper Lingula flags (White Leaved Oak shales, Dolgelly | 804b, 304e, 304f, 305d, 318. 318a, 318b, 318s-v, 366s.
~ group, Upper Ffestiniog growp). Micromitra pusilla—30th. ;

Obolus (Broggeria) salteri—304c.

Lingulella ferruginea—318u, 318v.

Lingulella lepis? —305d.

Lingulella nicholsoni—304b.

Lingulella (Lingulepis) pygmxa—304f.

Acrotreta sabrine—304b.

Orusia lenticularis—318, 318a, 318b, 318s-v, 366s.

Middle Lingula flags (Hollybush sandstone). 304¢, 366a. |
- Micromitra (Paterina) phillipsi—304g.
Lingulella davisi—366a.
Lingulella (Lingulepis) squamosa—304g.
Acrotreta sagittalis? —304¢.
(See 304g, p. 236, for additional associated forms.)

136 CAMBRIAN BRACHIOPODA.

Detailed stratigraphic distribution of Cambrian and Ordovician Brachiopoda—Continued. -

England, Scotland, and Wales—Continued.

/ Section. Loealities and species.

UPPER CAMBRIAN—Continued.

Lower Lingula flags. 318c, 318g, 318m, 366?, 366d-n, 366r?.
3 Lingulella davisi—318m, 366, 366d—n, 366r.
Acrotreta sagittalis—318c, 318g.

MIDDLE CAMBRIAN. .

Menevian group. 316b?, 318d, 318e, 318f, 318h, 318j, 318k, 3181, 318p, 318r.
Lingulella ferruginea—318e, 318h, 318), 318k, 3181.

Acrothele maculata—318d, 318e, 318f, 318h.

Acrotreta sagittalis—316b, 318h.

Orbiculoidea pileolus—318d, 318e, 318p, 318r.

Billingsella hicksi—318d, 318h, 318p.

Harlech grits. 318n, 3180, 318q, 366b.
Linguleila ferruginea—318n, 3180, 366b.
Orbiculoidea pileolus?—318q.

Solva.

MIDDLE? CAMBRIAN.

Caerfai group. 318i, 366c.
Lingulella primzva—318i, 366¢e.

LOWER CAMBRIAN.

Malvern ‘‘ quartzite” ( Comley, Serpulite grit, Fucoid beds). 8304c, 304d, 3040, 316c, 316d.
Micromitra scotica—316d.
Micromitra (Paterina) labradorica—3040.
Micromitra (Paterina) phillipsi—304e, 304d.
Lingulella zeus—31ée.
Obolella groomi—304c, 304d.
Olenellus lapworthi? —316c, 316d.
(See 304c, p. 236, for additional associated species.)

Finland.

See Sweden, Denmark, Finland, and Norway, where the horizons are more or less closely differentiated and
correlated, with complete lists of localities and included species.

Georgia.

See Tennessee, Georgia, and Alabama, where the horizons are more or less closely differentiated and correlated,
with complete lists of localities and included species.

Germany.
See Russia, p. 143 and footnote, for stratigraphic position of four localities from East Prussia.
Idaho.
See Utah, Blacksmith Fork section, where the Idaho localities are shown in their approximate stratigraphic position.
Iowa.
See Wisconsin, Michigan, Minnesota, and Iowa for general discussion of stratigraphy.
Labrador.
See Quebec, Ontario, and Labrador for general discussion of stratigraphy.
Maryland.
See Virginia and Maryland for general discussion of stratigraphy.
Michigan.
See Wisconsin, Michigan, Minnesota, and Tioga: general discussion of stratigraphy.
Minnesota.

See Wisconsin, Michigan, Minnesota, and Iowa for general discussion of stratigraphy.
? c=) ? ? >

DETAILED STRATIGRAPHIC DISTRIBUTION. 137

Detailed stratigraphic distribution of Cambrian and Ordovician Brachiopoda—Continued.

Missouri.

Section. Localities and species.

UPPER CAMBRIAN.

Elvins formation. 11d, 111, 369, 369b, 369c, 369d, 369e.
Obclus ismene—369.
Obolus matinalis?—11d.
Lingulella acutangula?—11 1.
Lingulella terana—369.
Linnarssonella girtyi—859.
Billingsella coloradoensis —11d, 111, 369d, 369e.
Billingsella major?—369e.
Eoorthis indianola—369, 369b.
Eoorthis remnicha texana?-—11d, 111.

MIDDLE CAMBRIAN.

Elvins formation (basal part or “‘ Edgewise beds’’).a lle, 11k, 369a.
Obolus matinalis?—ile.
Lingulella acutangula—11k.
Lingulella similis—i1e.
Lingulelia sp.—t\e.
Linnarssonella girtyi—11e. 11k.
A crotreta microscopica missouriensis—1le, 11k.
Billingsella coloradoensis—i1e.
Eoorthis wichitacnsis—369a.

Bonneterre limestone. 11j, 11m, 369f, 369¢, 369h.

Micromitra sp.—1lm.

Micromitra (Paterina) cf. stissingensis—11m.
Obolus lamborni—11j, 11m, 369f, 369h.
Obolus sinoe—11j.

Lingulella acutangula—11j.

Lingulella desiderata—369g.

Lingulella ef. ora—11m.

Dicellomus nanus—11j, 11m.

Dicellomus politus—1\m.

Lamotte sandstone.

Montana and Wyoming.

The sedimentation in Montana and northwestern Wyoming exhibits so many peculiarities that correlation is
difficult, even between sections only a few miles apart. The Wolsey shale occupies a position immediately above a
sandstone in the Little Belt Mountains and is Middle Cambrian in age. It can thus be closely correlated with the
similarly situated Flathead shales of Peale, which are also Middle Cambrian. On Dearborn River, however, a shale
which occupies the same stratigraphic position [see Walcott, 1908{, pp. 202-203] carries a typical Lower Cambrian
fauna in its lower part and Middle Cambrian in its upper layers. The sandstone underlying the Dearborn River shale
horizon is Lower Cambrian in age, and that underlying Peale’s Flathead shales has been found to contain a fairly well
developed Middle Cambrian fauna.

The Gallatin formation of Peale has a very wide geographic distribution, and collections have been made at many
localities. The various horizons can not be differentiated, but the faunas show clearly that his Gallatin is in part
Upper Cambrian and in part Middle Cambrian. A limestone in the Phillipsburg quadrangle that is believed to be the
equivalent of the Yogo limestone of the Little Belt Mountains has been found to contain both Middle and Upper
Cambrian fossils.

The localities (see index for numbers) give all the known data as to the stratigraphy of the different collections.

Nevada: Barrel Spring.

Other Lower » Cambrian localities and

Barrel Spring section. Localities and species in the Barrel species in Nevada and California
[Waleott, 1908f, pp. 188-189.] Spring section. shown in their approximate strati-
graphic position.

A section of Lower Cambrian strata studied by Mr. F. B. Weeks
near Barrel Spring, 16 miles south of the town of Silver Peak,
Nevada, is much like that east of Waucoba Springs, and has
about the same fauna at various horizons in it.

LOWER CAMBRIAN. R
eet.
1, Massive blue-mottled limestone, with 50 feet of sandy Archzocyathus and allied forms occur
limestone in the middle of the series.............- 737 throughout.

a It has been agreed, but too late for any other correction than the insertion of this footnote, that the ‘‘ Edgewise beds” should be placed in
the Upper Cambrian.

» Three scattering localities have been identified as Middle Cambrian, and eight localities were collected from the Emigrant formation (Upper
Cambrian) of Turner in the Silver Peak district. See index for locality numbers.

138

CAMBRIAN BRACHIOPODA.

Detailed stratigraphic distribution of Cambrian and Ordovician Brachiopoda—Continued.

Nevada: Barrel Spring—Continued.

Barrel Spring section.
(Walcott, 19081, pp. 188-189.]

Localities and species in the Barrel
Spring section.

Other Lower Cambrian localities aid
species in Nevada and California
shown in their approximate strati-
graphic position.

LOWER CAMBRIAN—Continued.

2. Sandy shales succeeded by coarse thin fine sandstone Feet.

1m, lp.

53, 58a, 174c,176,176a,178a, 312, 312a.

with buff limestone at top.......-.-..------------ 206 | In limestone: Mickwitzia occidens—53, 174c.
Micromitra (Paterina) prospecten- | Obolus?—174c.
sis—Im, Ip. Obolella vermilionensis—53, 176.
Nisusia (Jamesella) amii—im, 1p. Obolella sp.—58a, 174c, 176, 312a.
Scenella sp.—im, 1p. Trematobolus excelsis—53, 76a, 312,
Agraulos?—lm, 1p. 3124.
Olenellus fremonti—1p. Trematobolus sp.—178a.
Olenellus gilberti—im, 1p. Billingsella highlandensis—178a.
Wanneria gracile—53, 178a.
Olenellus fremonti—178a.
Holmia rowei—312.
3. Green calcareous shale, arenaceous at top.---.....-- 390 | 11, lv. 7, 141, 140, 14p, 175, 184, 313i.
Archxocyathus ?—lv. Obolus ?—175.
Micromitra (Paterina) labradorica | Lingulella (Lingulepis) rowei—l4p.
var.—ly. ‘ Kutorgina perugata—7, 175, 184, 313i.
Kutorgina cingulata—lv. Obolella vermilionensis—14p.
Kutorgina perugata—ly. Obolella sp.—l4o.
Siphonots eta? dubia—lv. Yorkia wanneri?—7.
Acrothele spurri?—1 1. Acrotreta claytoni—175, 184.
Acrotreta claytoni—11. Swantonia sp.—175.
Swantonia weeksi—lyv. Billingsella bivia—141, 14p.
Swantonia? sp.—lv. Wanneria gracile—l4p.
Stenotheca cf. clongata—lv. Olenellus fremonti—141, 14p.
Stenotheca ef. rugosa—lv.
Salterella—11.
Ptychoparia sp.—11, lv.
Wanneria gracile—lv.
Olenellus argentus—lv.
Olenellus gilberti—1 1.
4, Massive blue-mottled limestone. ..........-----.---. 49
5. Mainly green shales, some quartzitic shale, bands of
MES TONE Tai IO D meee eee ere pedecess 580
6. Green calcareous shale, with bands of limestoneat top 564 | li, 1k.
Olenellus claytoni—ii, 1k.
Olenellus fremonti—?
Olenellus gilberti—ii.
Ts JNWGESNIG TSS. - So = ose st oe so most bon soseeasensscos 750
8. Massive blue-mottled limestone. 81
9), (Green) calcareous'shalete <9. se oss sees. = 2-2 ee ee == 238
10. Mostly thin-bedded blue and gray shaly quartzite... 904
11. Siliceous limestones at base, then blue coral lime-
StONC 2a eee ese ee eee peo eee ena 1,349
12. Massive quartzite, shaly in places.......-...-..---.- 2220 eLE.

Nevadia wecksi—1f
Holmia rowei—if.

Base unknown.

DETAILED STRATIGRAPHIC DISTRIBUTION.

139

Detailed stratigraphic distribution of Cambrian and Ordovician Brachiopoda—Continued.

Nevada: Eureka District.

Eureka district section.
[Walcott, 1884b, p. 284; and 1908f, p. 184.]

Localities and species in the Eureka
district section.

Other localities and species in eastern
Nevada shown in their approximate
stratigraphic position.¢

ORDOVICIAN.
Pogonip limestone: Feet.
Interstratified limestone, argillites, and arenaceous
beds at the base, passing into purer fine-grained lime-
stone of a bluish-gray color, distinctly bedded and
INR? TOSSING WO bIS: 50 cocqncoesonousonaocoesdoascese 2,700

63, 201a, 202?, 203, 204, 209.
Obolus anceps—63.
Obolus mzra—2
Obolus (Westonia) iphis—201a.
Lingulella manticula—202.
Lingulella pogonipensis—201a.
Lingulella sp.—202.
Elkania ambigua—63, 202.
Acrothele sp.—201a.
Acrotreta idahoensis—201a, 202.
Acrotreta idahoensis alta—63.
Schizambon typicalis—201a.
Schizambon? —63.
Foorthis hamburgensis—201a, 202.
Syntrophia nundina—b63, 201a, 203, 204,
209.
(See 20la, 202, and 203, p. 228, for
additional associated forms.)

2212
Acrotreta sp. undt.—221.

214a, 214b, 318d, 313k.
Obolus rotundatus—313d.
Obolus sp. undt. e—214a.
Lingulella manticula—214b.
Linnarssonella minuta—313k.

PASSAGE BEDS.

Pogonip limestone (lower portion).

201, 203a, 205, 206a, 211?

Obolus mxra—205, 211.

Obolus (Westonia) sp. undt. b—205.

Lingulella manticula—211.

Lingulella pogonipensis—201, 203a, 205,
211.

Acrotreta?? cancellata—205.

Acrotreta curvata—205.

Acrotreta idahoensis alta—201. 206a.

Eoorthis hamburgensis, 201, 205, 211.
(See 203a and 211, pp. 228 and 229, for

additional associated forms.)

UPPER CAMBRIAN.
Dunderberg shale:
Yellowargillaceous shale, layers of chert nodules through-
out the bed, but more abundant near the top..-.-..--

567, 61, 62, 62a?, 64, 65, 66, 313h?, 313j.

Micromitra sculptilis—61, 62.

Obolus anceps—61.

Obolus discoideus—62, 64, 66, 313}.

Obolus mzra—61, 313}.

Obolus nundina—61.

Obolus (Westonia) iphis—64.

Lingulella desiderata—i6, 61.

Lingulella manticula—61, 62.

Lingulella punctata—61, 62.

Linnarssonella minuta--313h.

Acrotreta attenuata—61.

Acrotreta idahoensis—61.

Acrotreta idahoensis alta—61, 65.

Acrotreta spinosa—61, 62, 62a, 65.

Acrotreta sp.—61.

(See 56, 61, 62, 62a, 64, and 66, pp. 206,

211, and 212, for additional associ-
ated species. )

8e, 8f, 8n, 80, 8p, 313, 313f?.
Micromitra sculptilis endlichi—8o.
Micromitra sp.—80.

Micromitra (Paterina) crenistria—313.
Obolus discoideus—sf.

Obolus rotundatus—8o, 8p.
Lingulella arguta—313f.
Lingulella desiderata—8n, 313.
Tingulella isse—313.

Lingulella manticula—8e, 8f, 313f.
Lingulella punctata—8si, 8o.
Acrotreta idahoensis—313.
Acrotreta microscopica—8o.
Acrotreta pyxidicula—313f.
BLoorthis sp.—8o.

Eoorthis?—st.

Hamburg limestone:
Dark-gray granular limestone, surface weathering
rough and ragged, with only slight traces of bedding. 1, 200

MIDDLE CAMBRIAN.
Secret Canyon shale: ;
Yellow and gray argillaceous shales passing into shaly
limestone; near the top interstratiied layers of shale
and thinly bedded limestones

58, 60.
Micromitra sculptilis—s8.
Micromitra (Paterina) crenistria?—58.
Obolus discoideus—s8.
Obolus mxra—s8.
Obolus meconnelli—5s.
Obolus pundina—ss8.
Obolus (A critis?) rugatus—58.
Lingulella clarkei—8, 60.
Lingulella desiderata—58 60
Lingulella punctata—5&
Lingulella sp.—60.
Acrothele dichotoma—58.
Acrotreta idahoensis alta—52
Acrotreta microscopica—ss8.
Acrotreta pyxidicula—60.
(See both 58 and 60, pp. 209 and 211,
for additional associated species.)

7i, 8m?, 10w, 313b, 313c?, 313e.
Micromitra sculptilis—l0w.
Micromitra (Paterina) crenistria—313b.
Obolus meconnelli—8m,, 10w.
Obolus meconnelli decipiens—Sm.
Obolus rotundatus—7i.

Lingulella acutangula—313c.
Lingulella arguta—313e.
Lingulella desiderata—313b, 313¢.
Lingulella manticula—7i.
Lingulella punctata—7i.
Linnarssonella girtyi—313e.
Acrotreta idahoensis alta—7i, 313b.

@ Some of the localities placed in this column could as well have been correlated with the Utah (House Range) section. Locality 41 has been

entered under both.

140

CAMBRIAN BRACHIOPODA.

Detailed stratigraphic distribution of Cambrian and Ordovician Brachiopoda—Continued.

Nevada: Eureka District—Continued.

Eureka district section.

[Walcott, 1884b, p. 284; and 1908f, p. 184.]

district section.

Localities and species in the Eureka

Other localities and species in eastern
Nevada shown in their approximate
stratigraphic position.

MIDDLE CAMBRIAN—Continued.

Eldorado limestone:

Gray compact limestone, lighter in color than the Ham-
with thin seams of calcite; Feet.
bedding planes very imperfect.............-...-.---

burg limestone, traverse:

54, 55, 55b?, 57, 57b?, 592.
Lingulella arguta—4, 59.
3,050 | Lingulella punctata—4, 57.
Acrotreta attenuata—59.
Acrotreta definita—55, 57.

Orusia eurekensis—55b.
Orusia lenticularis—55b.
(See 55, 55b, 57, and 59,

species. )

Lingulelia desiderata—7, 57d.

Billingsella whit fieldi—55, 55b.

p- 205, 207,
and 210, for additional associated

14m, 313a,
Lingulella arguta—14m.
Lingulella arguta?—313a.

LOWER CAMBRIAN.

Shales occupying the position of the Pioche formation at
in the House Range (see p. 158),

Pioche, Nevada, ani
Utah, and correlated with it.

52.

52.
Callavia nevadensis—b2.
Olenellus fremonti—52.
Peachella iddingsi—52.
(Ete., see p. 201.)

Micromitra (Paterina) prospectensis—

41a

Micromitra (Iphidella) pannula—4\.
Acrotreta claytoni—41.

Acrotreta primzva—41.

Prospect Mountain quartzite.

Bedded brownish-white quartzite, weathering dark
brown; ferruginous near the base; intercalated thin
layers of arenaceous shales; beds whiter near the
SUMMA) ee ao eae ae eee eee eee

a Also in the Utah (House Range) section.

New Brunswick.

See Cape Breton and New Brunswick, where the horizons are closely differentiated and correlated, with com-.
plete lists of localities and included species.

Newfoundland: Manuels Brook, Conception Bay.

Manuels Brook section.
[Walcott, 1891b, pp. 260-261.]

Localities and species in the Manuels Brook
section.

Other localities and species in Newfoundland
Showa in their approximate stratigraphic posi-
ion.

LOWER ORDOVICIAN.

(Not exposed.)

114b, 314c, 314d, 314¢.
Obolus cyane—314d.
Obolus ? murrayi—314g.
Obolus (Lingulobolus) affinis—114b.
Obolus (Lingulobolus) spissus—114b.
Obolus (Westunia) rogersi—114b.
Lingulella bella—i114b.
Lingulella iole—314d.
Acrotreta gemma—314d.
Syntrophia calcifera—314c.
(See 3i4e and 314d, pp. 246 and 247, for addi-
tional associated forms.)

UPPER CAMBRIAN.

(8) Alternating bands of dark shale and Feet.
dark, compact sandstone. .......

400

3, 6u, 6v.

Lingulella ferruginea—6u.
Acrothele matthewi—3.

Acrotreta sagittalis transversa—3.
Orusia lenticularis—3, 6v.

114, 114a.

Lingulella bella—i14, 114a.

Lingulella bellula—114, 114a.
\

6s, 6y, 314a?, 314i?.
Lingulella billingsiana—314a.
Lingulella ferruginea ?—6s.
Lingulella randomensis—6y.
Orusia lenticularis—314i.

MIDDLE CAMBRIAN.

(7) Dark argillaceous shales, with thin
layers of limestone and sandstone

1 (zone A) and 2 (zone B).
Obolus fragilis—1, 2.
Lingulella ferruginea—1, 2.
Acrothele matthewi—1, 2.

2a, 6i (corresponding to zone A).
Lingulella ferruginea—2a.
Acrotreta sagittalis—6i.
Agnostus—6i.

at various horizons...-....---.- 295 | Acrotreta misera—1, 2. Microdiscus—6i.
(See both 1 and 2, p. 161, for additional asso-
ciated forms.)
(6) Green argillaceous shale, with thin la, 61, 6n, 6r, 314h?. 6h, 6w, 314.
layers of hard dark ferruginous Obolus fragilis—la. Acrotreta misera—th, 314.
sandstone interbedded at several Lingulella ferruginea—1a, 6n, 6r. Acrotreta sagittalis—6w. C
HOIZONS He yao eee ees 270 | Acrothele matthewi—1a, 61, 6n. (See 314, p. 246, for additional associated forms.)

Acrothele prima costata—6n.
Acrotreta misera—6n, 314h.
Acrotreta?—61.

Boorthis papias—61.

DETAILED STRATIGRAPHIC DISTRIBUTION. 141

Detailed stratigraphic distribution of Cambrian and Ordovician Brachiopoda—Continued.

Newfoundland; Manuels Brook, Conception Bay—Continued.

I . Antes e Aa 0 ps Other localities and species in Newfoundland
[Waleott 18515. BD. 860.261 ] Pics aaa species inthe Meas TOOT shown in their approximate stratigraphic posi-
ety . tion.
MIDDLE CAMBRIAN—Continued.
(5) Calcareous sandstone, with pinkish Feet.
limestone in irregular masses. - -- 2
(4) Reddish-colored argillaceous shale. 4
(3) Greenish argillaceous shale......_. 40 6g3
Micromitra (Iphidelia) ornatella—6g.
Micromitra (Iphidella) pannula maladensis—6g.
Lingulella ferruginea—6g.
Acrothele matthewi—6g.
Acrotreta misera—6g.
Acrotreta sagittalis—6g.
LOWER CAMBRIAN. 50, 314b.
Kutorgina granulata—314b.
Obolella atlantica—5o.
Olenellus?—5o.
bn.
Obolella atlantica—bn.
Callavia bréggeri—in.
{2) Irregular beds of calcareous sand- 5r, 41. 51, 5p, 5t, 41a, 314e, 314f.
stone, siliceous limestone, and Micromitra (Paterina) labradorica—r. Micromitra (Paterina) bella—s14e.
greenish argillaceous shale, cover- Obolella atlantica—41. Micromitra (Paterina) labradorica—5l, 5t, 41a,
ing the upper surface of (1) -.--.- 0-25 | Callavia broggeri—asr, 41. 314e, 314f.
(See 41, p. 199, for extensive list of associated | Obolella atlantica—5p, 5t, 41a.
species.) Obolella chromatica—314f. __
si Mesonacis vermontana—314f.
Callavia bréggcri—sp, 5t, 41a.
Olenellus ?—5 1.
(1) Coarse conglomerate, in massive
layers, resting on gneiss. -......- 35

New York.

Five or six of the New York localities are scattering; the remainder may be separated into two groups, Upper
Cambrian (Potsdam) and Lower Cambrian. In each of these divisions little stratigraphic differentiation is possible,
but the localities (see index for numbers) give all known stratigraphic data.

Norway.

See Sweden, Denmark, Finland, and Norway, where the horizons are differentiated and correlated, with com-

plete lists of the localities and included species.
Nova Scotia.

See Cape Breton and New Brunswick, where the horizons are closely differentiated and correlated, with com-
plete lists of localities and included species.

Oklahoma: Arbuckle Mountaius.

For the Arbuckle limestone the section 7 miles north of Springer, on the south side of the Arbuckle Mountains, is
used, and for the Reagan sandstone a section measured by H. O. Ulrich in sec. 2, T. 4 N., R. 13 W., on the north side
of the Arbuckle Mountains, 15 miles northwest of Fort Sill.

Other localities and species in
Oklahoma in their approxi-
mate stratigraphic position.

Localities and species in the

Springer section, south side of Arbuckle Mountain. Springer section.

ORDOVICIAN.
Arbuckle limestone. a Feet.
1. Compact dolomitic limestone with occasional calciferous fossils,
MCAT] Yemen se yee tease oe Seo ele osigeae Seecne Bis eie are see 4,500

2. Rather thin-bedded, mostly compact, gray or blue limestone, with
-granocrystalline layers in lower half containing fossils, mainly
(it) ICS) 8 ine Saaeseseodonie a aanaa ea ne saa eS Eacaaaoasbosnsoce 250
3. Crystalline limestone weathering dark and breaking down into
rough bowldery jointed masses, in which the sedimentation is much
obscured. Uppermember granocrystalline and gray; middle mem-
ber with white and pink marble; lower member granocrystalline
andidankserava LOnWwHit Chae ee ene nase eee eee ee eee 305

@ The section of the Arbuckle limestone was measured on the south side of the Arbuckle Mountains, 7 miles north of Springer.

142 CAMBRIAN BRACHIOPODA.

Detailed stratigraphic distribution of Cambrian and Ordovician Brachiopoda—Continued.

Oklahoma: Arbuckle Mountains—Continued.

Springer section, south side of Arbuckle Mountains.

Localities and species in the
Springer section.

Other localities and_ species in
Oklahoma in their approxi-
mate stratigraphic position.

UPPER CAMBRIAN.

Arbuckle limestone: Feet.
4. Heavy bedded compact gray limestone...................---------- 4
5. Thin-bedded shaly limestone with fossils.............--.----------- 4 | 12m. ; 9z, 12).

Obolus tetonensis ninus—
12m.

Lingulella similis—12m.

Eoorthis remnicha eats
12m.

Boorthis wichitaensis—9z, 12).

6. Heavy bedded compact gray limestone. -.-.......-.-.-.-------.---- 4

7. Thin-bedded shaly and clayey limestone, often yellow, with some
limestone conglomerate; no fossils....-....-...--.---------------- 0-40

Section measured in sec. 2, T.4 N., R. 13 W., north side of Arbuckle Mountains,
by BE. O. Ulrich.

Localities and species oc-
curring in the section
quoted.

Localities and species occurrin
in the Springer section (12k an:
12n) and elsewhere in Okla-
homa: stoma in their approxi-
mate stratigraphic position.

UPPER CAMBRIAN.

Reagan sandstone: Laps Feet.
1. Highly calcareous sandstone, with numerous pure crystalline lime-
stone lenses and layers containing fossils....-...--.-.-.----------- 175

(125 feet above the base.)

Su.

Obolus tetonensis ninus—9u.
Lingulella similis—9u.
Hoorthis indianola—9u.
Eoorthis wichitaensis—9u.
Syntrophia primordialis—9u.

9q?, 9s, Iw, 12n, 12p?.
Obolus tetonensis ninus—9q, 9s,
12n, 1p.
Lingulel asimilis—9s, 12n, 12p.
Lingulella ora—9q.
Lingulella (Lingulepis) acumi-
nata—9q, 9s, 12n, 12p.
Linnarssonella girtyi—9q, 12p.
Acrotreta curvata—12p.
Acrotreta microscopica—i2n, 12p.
Acrotreta ulrichi—l2p.
ELoorthis indianola—9w, 12n, 12p.
Hoorthis remnicha—12n, 12p.
Boorthis remnichaterana—i2n.
Hoots wichilaensis—9q, 9s, 12n,
12
Eoorthis wichitaensis leviuscu-
dus—12n, 12p.
Syntrophia primordialis—12n.

(100 feet above the base.)

ot.

Obolus matinalis—9t.
Oodolus tetonensis ninus—It.
Lingulella similis—9.

A crotreta microscopica—t.
Loorthis indianola—9.

12k.

Obolus tetonensis ninus—12k.

Lingulella similis—12k.

Acrotreia microscopica—12k.

Loorthis indianola—12k,

Hoorthis remnicha—12k.

Hoorthis wichitaensis—12k.

Hoorthis wichitaensis leviuscu-
lus—12k.

(90 feet above the base.)

9p.

Obolus tetonensis ninus—op.
Lingulella ora—9p.
Linnarssonella girtyi—9p .

Ox.
Dicellomus politus.

(45 feet above the base.)

12s.
No brachiopods.
Trilobites not studied.

9v?.

Lingulella (Lingulepis) acumi-
nata—9v.

Linnarssonella girtyi—9v.

2. Originally massive calcareous sandstone, now leached into laminar,
favose masses, forming small blufis.......-....-.-....------------ 25

(Beds between 2 and 3 are fossiliferous.)

9x:

Obolus tetonensis ninus—9r.
Lingulella similis—9r.
Linnarssonella girtyi—9r.
Acrotreta microscopica—9r.

3. Whitish crystalline limestone, almost made up of fragments of large
eystids. With the limestone small lenses and layers of glauconitic
Sandstonelarenterpolated anes seen eee eee nese eee eae 24

Base formed of a glauconitic grit 20 feet thick, containing several layers of por-
phyry pebbles and resting on porphyry.

a The section of the Reagan sandstone was measured on the north side of Arbuckle Mountains, in sec. 2, T.4.N., R.13 W. The Reagan is much
more fossiliferous and has a greater development in the section northwest of Fort Sill, in Comanche County, than it has on the south side of the

Arbuckle Mountains, in Carter County.

DETAILED STRATIGRAPHIC DISTRIBUTION. 143

Detailed stratigraphic distribution of Cambrian and Ordovician Brachiopoda—Continued.
Ontario.
See Quebec, Ontario, and Labrador for general discussion of stratigraphy.
Pennsylvania.

All. but two of the Pennsylvania localities (see index for numbers) are from approximately the same horizon in the

Lower Cambrian. One locality (346b) is from the Upper Cambrian and one (48d) from the Middle Cambrian.
Quebec, Ontario, and Labrador.

Three general horizons from Quebec and Ontario are represented in the collections: An Ordovician (Chazy?), an
Upper Cambrian equivalent to the Potsdam of New York, and a Lower Cambrian in limestone pebbles in a conglomer-
ate. The Jower Cambrian forms may be compared with those occurring in localities 392a, 392c, and 3921, all at the
Straits of Belleisle, Labrador. See index for numbers of all localities in Quebec, Ontario, and Labrador.

Russia.a

Section. Localities and species.

ORDOVICIAN. | 337e. . 2
Tewe limestone (D). | Siphonotreta unguiculata—337e.

Itfer limestone (C3).

Kucker limestone (‘‘ Brandschiefer’’) (C2). 337d.
Siphonotreta unguiculata—337d.

Echinosphzrites limestone (C1). 336, 336g7, 336v, 336w, 336x, 386i-l.
Volborthia recurva—336g.
Acrotreta subconica—336.
Siphonotreta unguiculata—336g, 336V, 336w, 3386X, 386i, 386].
Siphonotreta verrucosa—336w, 386i, 386k, 3861.

Upper ‘‘ Linsenschicht.”’

PASSAGE BEDS.

Orthoceratite (Vaginoceras) limestone (“ Vaginatenkalk’’) | 386d, 336e, 336f, 336z, 337, 337a, 337b, 337c, 337f, 337g, 337h, 337j, 337k, 3371,
B3): 3 337m, 396n, 396p.

B3;= Asaphus eichwaldi zone. Volborthia recurva—337j.
B36= Asaphus raniceps zone. Obolus (Mickwitzella) siluricus—336f.
B3a= Asaphus expansus zone. Obolus (A critis) antiquissimus—336d, 336e, 337h, 396n, 396p.

Siphonotreta unguiculata—336e, 3362, 337, 337a, 337b, 337¢c, 337k, 3371.
Siphonotreta verrucosa—336e, 3371, 337g, 337m.

Lower ‘‘ Linsenschicht.””

Glauconite limestone (B2): 836y, 396g-0, 396z.
B2;=Asaphus lepidurus zone. Obolus (Acritis) antiquissimus—396g-0, 3962.
B2¢= Asaphus broggeri zone. Siphonotreta unguiculata—33by.
B2a= Megalaspis planilimbata zone. Siphonotreta verrucosa—336y.

337i, 395v?, 395w, 395x?, 395y?, 396, 396a-f, 396x, 396y.

Obolus (Mickwitzella) siluricus—337i, 395v, 395w, 395x, 395y, 396, 396a-c, 396e, 396x,
396y.

Obolus (Acritis) antiquissimus—395w, 396d, 396x, 396y.

Obolus (Acritis) antiquissimus ventrosus—396d.

Lingulella (Leptembolon) lingulzformis—396, 396a-d, 396f.

Lingulella (Leptembolon) lingulzformis solidus—396a.

Glauconite sandstone (B1).

UPPER CAMBRIAN.
Dictyograptus slate.

Ungulite grit or Obolus sandstone. 9d, 336a, 336b, 336c, 336h, 336j-u, 395, 395a-e, 395z.
Obolus apollinis—9d, 336a-c, 336k—m, 336r—u, 395, 395b, 395z.
Obolus apollinis ingricus—336a, 336c, 336s, 336t, 395, 395a, 395z.
Obolus apollinis maximus—336j, 395.

Obolus apollinis quenstedti—395, 395a, 395z.

Obolus eichwaldi—395.

Obolus elegans—395, 395b.

Obolus panderi—395.

Obolus schmidti—395.

Obolus triangularis—9d.

| Obolus volborthi—395.

Obolus sp.—9d, 336p.

Obolus (Schmidtia) acuminatus—395, 395a-e.

Obolus (Schmidtia) acuminatus alatus—395, 395a-e.

Obolus (Schmidtia) acuminatus humeratus—395, 395a, 395b.
Obolus (Schmidtia) acwminatus subtriangularis—395, 395b.
Obolus (Schmidtia) celatus—3360, 336p, 395.

Obolus (Schmidtia) celatus precisus—395, 395a-e.

Obolus (Schmidtia) crassus—395, 395a-e.

Obolus (Schmidtia) crassus angulatus—395, 395b.

a Four drift bowlders found in East Prussia (localities 386i-1) are included.

144

CAMBRIAN BRACHIOPODA.

Detailed stratigraphic distribution of Cambrian and Ordovician Brachiopoda—Continued.

Russia—Continued.

Section.

Localities and species.

Ungulite grit or Obolus sandstone—Continued.

9d, 336a, 336b, 336c, 336h, 336j-u, 395, 395a-e, 395z—Continued.
Obolus (Schmidtia) obtusus—395, 395b.

Obolus (Schmidtia) obtusus acutus—395.

Obolus (Schmidtia) obtusus ellipticus—395, 395b.
Obolus (Schmidtia) obtusus extenuatus—395.
Obolus (Schmidtia) obtusus latus—395.

Obolus (Schmidtia) obtusus longus—395.

Obolus (Schmidtia) obtusus minutus—395.
Lingulella (Leptembolon) lingulxformis—395.
Helmersenia ladogensis—3360-q .

Keyserlingia buchi—9d, 336a, 336n—p, 395, 395b.
Schizambon? esthonia—336h.

Obolus conglomerate and sandstone below it (Schmidtia con-
glomerate).

336i, 395f-u.

Obolus apollinis—395f.

Obolus apollinis maximus—395f. __

Obolus triangularis—336i, 395g, 3951.

Obolus triangularis inornatus—395¢.

Obolus (Schmidtia) celatus—395g-i, 3950, 395s-u.

Obolus (Schmidtia) celatus orbiculatus—395g-r.
Obolus (Schmidtia) celatus precisus—395g-r.

Unconformity.

\ LOWER CAMBRIAN.
Fucoid sandstone.

Mickwitzia conglomerate.

396q-w.
Mickwitzia monilifera—396q-w.

Mesonacis mickwitzi—396r, 396u, 396v.

Blue clay.

Scotland.

See England, Scotland, and Wales, where the horizons are more or less closely differentiated and correlated,
with complete lists of localities and included species.

South Dakota and Wyoming.

Three of the localities (302e, 302p, and 302u) occur in the upper part of the Deadwood formation and have been
referred to the Upper Cambrian; the remainder (see index for numbers) occur in the Middle Cambrian at various

more or less closely related horizons in the Deadwood formation.

Sweden, Denmark, Finland, and Norway.

(See also Montana and Wyoming.)

Section.

Localities and species in Sweden, Denmark, and
Finland in their approximate stratigraphic
position.

Localities and species in Norway in their approxi-
mate stratigraphic position.

PASSAGE BEDS,

Orthoceras limestone:
Didymograptus slate.

Phyllograptus slate (Planilimbata lime-
stone).

323, 323i.
Obolus (Bréggeria) salteri—323i.
Acrotreta sagittalis—323.

390, 390f. (Both given as occurring between
either the lower graptolite slate or the Ortho-
ceras limestone and the Ceratopyge lime-
stone.)

Protorthis hunnebergensis—390f.

Loorthis tullbergi—390.

Ceratopyge limestone (Say) (A patocephalus
zone).

309, 310, 310j, 310w?, 310x, 320w, 323j, 390e.

Obolus? inflatus—310x.

Obolus (Bréggeria) salteri—309, 323).

Lingulelia lepis—309, 310, 310j, 310w, 320w.

Acrothele ceratopygarum—3s10.

Acrotreta carinata—309, 310.

Acrotreta circularis—309, 310.

Acrotreta sagittalis—309.

Eoorthis daunus—s810, 310}.

Hoorthis wimani—310j.

‘Eostrophomena elegantula—310, 310j, 390e.

(See 309 and 310, pp. 240 and 241, for additional

associated forms.)

8x, 323, 323c-h, 3232.
Obolus (Broggeria) salteri—8x, 323e, 323f, 323h. \
Lingulella lepis—8x, 323c, 323f, 323h.
Lingulella sp.—8x.
Lingula sp.—323h.
Acrothele ceratopygarum—323h.
Acrothele coriacea—8x.
Acrotreta seebachi—8x, 323d—h.
Acrotreta sagittalis—8x, 323.
Acrotreta sagittalis var.—323h.
Eoorthis daunus—8x, 323f, 323h, 3232.
Eoorthis wimani—8&x.
(See 8x, 323f, and 328h, pp. 173 and 257, for
additional associated forms.)

DETAILED STRATIGRAPHIC DISTRIBUTION.

145

Detailed stratigraphic distribution of Cambrian and Ordovician Brachiopoda—Continued.

Sweden, Denmark, Finland, and Norway—Continued.

Section.

Localities and species in Sweden, Denmark, and
Finland in their approximate stratigraphic
position.

UPPER CAMBRIAN.

Ceratopyge slate (3a8) (Shumardia zone).

309i?, 309j?, 30912, 310d, 310h?, 310k, 310r,
810s, 321e-n, 328k, 390b, 390c, 390i, 39002?.

Obolus (Bréggeria) salteri—309i, 309}, 3091, 310d,
310h, 328k, 390i.

Lingulella concinna—310h.

Lingulella ferruginea—310d.

Lingulella lepis—310d, 3211, 321m.

Lingulella sp. undt. a—310k.

Obolella sp.—321n.

Acrothele borgholmensis—310d.

Acrotreta elandica—310r, 310s.

Acrotreta cf. sagittalis—321e-n.

Acrotreta seebachi—310d.

Acrotreta sp.—321n.

Eoorthis christianie—310d.

Eoorthis wimani—390b, 390c.

Billingsella exporrecta—310h.

Orusia lenticularis—3900.
(See 321e-n, 390b, 390c, pp. 254, 255, 279, and

280, for additional associated forms.)

Localities and species in Norway in their approxi-
mate stratigraphic position.

828a, 323w, 323x, 323y.

Obolus sp—323w.

Obolus (Broggeria) salteri—323w.
Lingulella lepis—323a.

Acrotreta sagittalis—323a.
Loorthis christianiex—323x, 323y.
Eoorthis wimani—323w.

Bryograptus slate (8aa).

309a.
Lingulella lepis—309a.

Dictyograptus slate (Obolus sandstone).

9e, 309b, 309h, 310n, 310t, 310u, 310v, 311v, 31lw,
$21, 321a-d, 3210, 321z, 390g, 3901, 390m.

Obolus apollinis—9e, 311v, 311w, 321, 321a-d, 3210,
3901, 390m.

Obolus triangularis—310n.

Obolus (Bréggeria) salteri—309h, 321x, 390g.

Obolus (Schmidtia) celatus orbiculatus—321d.

Obolus (Schmidtia) obtusus—821c.

Lingulella lepis—309b.

Acrotreta sp.—310t-v.

Orthis sp.—31lw.

Acerocare zone, Olenus zone, and Btage 2b.

309e, 309m, 310a, 390n, 390p?.

Acrotreta conula—310a.

Orusia lenticularis—309m, 310a, 390n, 390p.
Hoorthis christianiex—309e.

Parabolina spinulosa—390n.

9f, 3231-v.

Lingulella lepis—9f.

Orusia lenticularis—9f, 323 lv.

Parabolina spinulosa—323 |, 323m, 3230-u.
Peltura scarabzoides—323n.

MIDDLE CAMBRIAN.

Agnostus lzvigatus zone.

810i?, 310q, 3202, 320a, 320b, 320r, 320u, 321p.
Micromitra pusilla—320u.

Lingulella agnostorum—3s10i.

Lingulella ferruginea—310q.

Acrothele coriacea—310i, 320b, 320r.

Acrothele (Redlichella) granulata—320b.
Acrotreta parvula—310i, 320, 320a.

Billingsella exporrecta—320b, 321p.

Billingsella exporrecta rugosicostata—320b.

Paradoxides forchhammeri zone ( Btage 1d, Nor-
way, Andrarum limestone; and Coronatus
zone, 320i-k).

8w, 16h, 16j, 310b?, 3101, 310y, 310z, 320c,
320e2, 320f, 320g, 320i2, 320j?, 320k?, 320m,
320n, 320p, 320q, 320v, 320y, 320z, 321q,
8321r, 321t?, 321u2, 32ly?, 321z?, 334, 334b,
334e, 334f?, 334¢?, 334h.

Micromitra pusilla—s8w, 16h, 16j, 320f.

Micromitra (Iphidelia) ornatella—8w, 16h, 3208,
320n, 320y.

Obolus schmalenseci—8w, 16h.

Lingulella ferruginea—8w, 16h, 16j, 310y, 310z,
320m, 320n.

Lingulella linnarssoni—320n.

Lingulella sp.—8w.

Dicellomus sp. undt.—3101.

Acrothele coriacea—8w, 16h, 16j, 321f, 320g, 320k,
320m, 320n, 320p, 320q, 320v, 320y, 321q, 334b,
334e, 334f, 334h.

Acrothele intermedia—16h, 320i, 320j, 320k, 320q.

Acrotreta sagittalis—8w, 16h, 16j, 321y, 321z, 334h.

Acrotreta schmalenseei—8w, 16h, 16), 310b, 320c,
320e, 320m, 320n, 321q, 334.

Acrotreta socialis—8w, 320n, 334g.

Billingsella exporrecta—310z, 320g, 320m, 320n,
320p, 320y, 3202, 321q, 321.

Bulingselia exporrecta Tugosicostata—320m, 320n,
320p.

Billingsella lindstr6mi—320m, 320n, 320p, 320q,
320y, 321t, 321u.

Orusia lenticularis—320f.

(See 8w, 16h, 320q, and 334g, pp. 173, 186, 253

and 262, for additional associated forms. ) ;

324c, 324d?.

Micromitra (Iphidelia) ornatella—324c.
Lingulella ferruginea—324d.

Acrothele cortacea—324c.

§62667°—vo1 51, pr 1—12-_10

146

CAMBRIAN BRACHIOPODA.

Detailed stratigraphic distribution of Cambrian and Ordovician Brachiopoda—Continued.

Sweden, Denmark, Finland, and Norway—Continued.

Section.

Localities and species in Sweden, Denmark, and
Finland in their approximate stratigraphic
position.

Localities and species in Norway in their approxi-
mate stratigraphic position.

MIDDLE CAMBRIAN—Continued.

Paradoxides davidis zone.

16k, 161.
Acrothele coriacea—16k, 161.
Acrotreta sagittalis—l6k, 161.

Paradoxides tessini zone, Agnostus merusrons
zone, Conocoryphe exsulans zone,and tage 1c
(Norway).

aD 8100, 311x, 320d, 320h, 334a, 334c,

Obolus schmalenseeci_1 61.

Obolus (Westonia) finlandensis—311x.
Lingulelia ferruginea—310m, 3100.
Lingulella sp.—16i.

Acrothele coriacea—334e, 334d.
Acrothele intermedia—320h, 334a.
Acrotreta sagittalis—16i.

Acrotreta schmalenseei—320d.
Liocephalus impressa—16i.

8244, 324b. :
Acrothele coriacea—324a, 324b.
Agnostus nudus—324h.

Paradoxides elandicus zone.

8z, 309f2, 310c, 310p, 3201, 320s?, 320t.

Obolus sp. undt. g—3201.

Lingulella ferruginea—310p.

Acrothele coriacea—3201.

Acrothele (Redlichella) granulata—8z, 309f, 3201,
320s, 320t.

Acrotreta schmalenseei—310c, 310p.

Acrotreta socialis—8z.

Acrotreta sp.—8Zz.

Billingsella exporrecta—3201.

Billingselia lindstr6mi—3201.
(See 8z, p.173, for additional associated forms. )

323b.
Acrotreta schmalenseei—323b.

MIDDLE ? CAMBRIAN.

311, 31la-u, 31ly, 3200.
Mickwitzia formosa—311 1, 311s.
Mickwitzia monilifera—211e, 3111, 3111, 311q, 3117,
3llu.
Optaes (Westonia) alandensis—311j, 311k, 311m,
lly.
Obolus (Westonia) balticus—311h, 3110, 311t.
Obolus (Westonia) bottnicus—311, 31le.
Obolus (Westonia) wimani—aile, 311g, 311i, 311t.
Lingula or Lingulella—siie, 311), 311p, 311t, 31ly.
Acrothele coriacea—3200.
Acrotreta eggegrundensis—811, 311a, 311d.
Acrotreta uplandica—311b, 311p.
Acrotreta uplandica limoensis—311n.
(See 311, 31ic, 311g, 311k, 311m, 311n, 311s ,311t,
3lly, pp. 243-245, for additional associated
ieee

LOWER CAMBRIAN.

Holmia kjerulfi zone (Mesonacis torelli zone).

820x, 321s, 321v.

Lingulella nathorsti—320x.
Obolella lindstromi—321s, 321v.
Obolella mobergi—321s, 321v.
Mesonacis torelli—321v.
Holmia kjerulfi—320x.

8y, 324.

Lingulella sp.—324.

Obolelia mobergi—8v, 324.
Obolella (Glyptias) favosa—324.
Acrothele bellapunctata—8v.
Holmia kjerulfi324.
Arionellus—324.

Fucoid sandstone.

ea 809d, 310e?, 310f?, 310¢?, 390a?, 390d,
h.

ee (Paterina) wndosa—310f, 390a, 390d,
Obolelia (Glyptias) favosa—309¢, 309d.

Acrothele sp. undt.—310e.

Acrothele sp. undt.—310f, 310g.

Discinella—310f, 390a, 390d, 390h.

- Eophyton sandstone (Mickwitzia conglomerate,
Sparagmite sandstone).

8y, 390j, 390k.
Mickwitzia monilifera—390j, 390k.
Mickwitzia pretiosa—390j. :
Lingulelia nathorsti—8y.
(See 8y and 390j, pp. 173 and 280, for additional
associated forms.)

DETAILED STRATIGRAPHIC DISTRIBUTION.

147

Detailed stratigraphic distribution of Cambrian and Ordovician Brachiopoda—Continued.

Tennessee, Georgia, and Alabama.

Section.

Localities and species in Tennessee in their
approximate stratigraphic position.

Localities and species in Georgia and Alabama
in their approximate stratigraphic position.

UPPER CAMBRIAN.

Enox dolomite.

7d?, 12q, 105, 1070, 107u, 1227, 122a%, 128%,
and 128a?.

Obolus lamborni—7d, 122.

Obolus willisi_122..

Lingulella desiderata—1070, 107u, 122, 122a.

Lingulella ino—7d.

Linguleila sp.—128a.

Lingulella?—128.

Lingulella (Lingulepis) acwminata—105.

Acrotreta kutorgai—107o, 107u.

Syntrophia campbelli—12q.

93, 93a, 93n, 980, 93x, 940, 96, 3612, 3622.
Micromitra alabamaensis—940.

Micromitra (Iphidella) pannula—96.

Obolus rotundatus—96.

Obolus willisi—93, 93n, 93x.

Linguleila desiderata—93, 93a, 930, 940, 96, 361, 362.
Lingulella leos—96.

Acrotreta kutorgai—361.

Acrotreta sp.—940.

MIDDLE CAMBRIAN.

Nolichucky shale.

See

2z, 1la??, 124, 124a, 374c, 374d?.

Micromitra alabamaensis—124.

Obolus lamborni—124a.

Obolus lamborni minimus—124. _

Obolus sinoe—1la.

Lingulelia tarpa—ila.

Lingulella (Lingulepis) acwminata—124a, 374d.
Dicellomus appalachia—2z, 11a, 124a, 374¢c.

Maryville limestone.

Rogersville shale.

third column for species.

Honaker limestone
2z’. Dicellomus appalachia.

Conasauga shale, not differentiated in Georgia and Alabama.

Rutledge limestone.

123.
Micromitra alabamaensis—123.
Ptychoparia—123.

18%?, 101, 101a, 101b, 102, 102c?, 121, 121a?.
Micromitra alabamaensis—121, 121a.
Micromitra (Iphidella) pannula—101.
Obolus lamborni—101b, 102, 121.
Obolus lamborni mimimus—101, 101a.
Obolus willisi— 101b, 121.

Lingulclla desiderata—101a.
Dicellomus appalachia—102.
Acrotreta kutorgai?—18.

Acrolreta rudis—101a, 102c, 121.
Billingsella appalachia—121.
Wimanella harlanensis—121.

16, 560, 56q, 56u, 89, 90, 90a, 90b, 90c, 90x,
91, 92x, 94, 94a, 94x, 94xx, 95a, 96b, 96x?,
137, 138%, 189, 139a, 140, 140a, 140c, 141a,
144c?, 1452, 146, 362a?.

Micromitra alabamaensis—90x, 94, 94a, 95.

Micromitra (Paterina) major—90.

Obolus lamborni—140a.

Obolus sinoe—92x.

Obolus willisi94, 94a, 96b, 140a, 146, 362a.

Obolus (Westonia) ella—90, 141a.

Lingulella buttsi90b, 90e.

Lingulella desiderata—90b, 94xx, 139.

Lingulella hayesi—90x, 94a.

Lingulella nanno—16, 91.

Lingulella quadrilateralis—b56q, 91, 140a.

Lingulella similis—90, 92x, 138, 140c, 145.

Lingulella sp.—140c.

Lingulella (Linaulepis) acwminata—s9.

A crothele bellula—9nx, 94x.

Acrotreta concentrica—96x.

Acrotreta kutorgai—90, 90b, 90x, 137, 139a, 140.

Acrotreta sp.—h6o, 56u, 94xx.

Dicellomus appalachia—16, 89, 90a, 90b, 91, 144c.

Wimanella anomala—90.

A gnostus—90b.

Ptychoparia sp.—56q, 90b, 90x.

Anomocare—90x.

Olenoides curticei—90, 90x.

Laotira cambria—90x..

.| Brooksella alternata—90x.

Rome formation.

9%, 9a2, 10a, 10b, 11, 12?, 13, 18b, 14a, 103,
103a, 103b, 104?, 106, 106a?, 107, 107a,
107b, 1172, 117c, 118, 1192, 3742, 374a?, 374b?,
374e%.

Micromitra alabamaensis—14a.

Obolus lamborni—103.

Obolus lamborni minimus—103a, 118.

Obolus pandemia—10a.

Obolus willisi—106a, 107a, 107b, 374e.

Obolus (Westonia) ella—14a.

Lingulella auga—10a, 10b.

Lingulella desiderata—9, 9a, 103b, 107a, 117.

Lingulella ino—11, 13, 138b.

Lingulella similis—9a, 10a, 14a, 106, 374.

Lingulella tarpa—11.

Lingulella?—107b.

Dicellomus appalachia—103a, 104, 107, 107b, 117c,
119, 374a, 374b.

Tinnarssonella tennesseensis—12, 13, 107b.

Wimanella harlanensis—107.
Wimanella saffordi—l 4a.

1c, 14, 138a, 142, 164f?.
Micromitra (Iphidella) pannula—14.
Obolus? sp.—1h4f.

Lingulella ino—138e.

Lingulella similis—138a.

Acrotreta kutorgai?—-142.

Billingsella appalachia—14.
Dorypyge?—i4.

LOWER CAMBRIAN.

Rome formation, basal part, locally known
in Alabama as “‘ Montevallo shale.”’

17b, 56c.

Micromitra (Paterina) major—17b, 56c.
Micromitra (Paterina) williardi—17b, 56c.
Obolus smithi—17b, 56e.

Wimanella shelbyensis—17b, 56e.
Pzdeumias transitans—56c.

Wanneria halli—béc.

A graulos?—56c.

Hyolithes—56e.

Beaver limestone.

Weisner quarizite.

59m.

Obolella cf. atlantica—59m.
Obolella cf. crassa—59m.

A rchxocyathus—59m.
Stenotheca cf. rugosa—bh9m.
Olenellus thompsoni—59m.

148

CAMBRIAN BRACHIOPODA.

Detailed stratigraphic distribution of Cambrian and Ordovician Brachiopoda—Continued.

Texas.

The Texas localities are from the Upper Cambrian, at about the stratigraphic horizon of the Reagan sandstone

of the Oklahoma section.

Utah: Blacksmith Fork, Cache County.

Blacksmith Fork section.

Localities and species in

Other localities and species in
Utah and Idaho shown in

[ Walcott, 1908f, pp. 190-200.) the oe smith Fork’) their approximate strati-
¢ graphic position.

The Blacksmith Fork section is located in Blacksmith Fork Canyon, on the

east side of Cache Valley, in the Wasatch Mountains, between Ute and Logan
Peaks, about 10 miles east of ene in northern Utah.

This section is 230 miles northeast of the House Range section (Utah) and is
north of the greater effect of the pre-Cambrian Uinta Mountain uplift and island.
The character of the sediments derived from the Uinta area is shown by the con-
tinuation of the arenaceous deposits up to the middle of Middle Cambrian time,
whereas in the House Range section the arenaceous deposits cease before the Mid-
dle Cambrian fauna appears. It is not until after the Belt Mountain and Kintla
(of the 49th parallel) uplifts to the north are passed that the order of sedimenta-
tion as shown in the Mount Bosworth section is again of the type of the House
Range section.

ORDOVICIAN.
Feet.

1. Dark, bluish-black, and gray limestone. In the basal bed imme- 185z. 105x?.
diately above the Cambrian a fine fauna occurs. The lime- Eoorthis desmopleura—185z. | Obolus (Westonia) elongatus—105x.
stone is of the same character as that of the Upper Cambrian Syntrophia nundina—185z.
for 190 feet below, and, except for the change in the fauna, Orthoceras—185z.
there is no break in the section. One of the characters Endoceras—185z.
common to the Cambrian and the superjacent Ordovician is Fragments of trilobites—185z.
the presence in most layers of flattened concretionary nodules
and stringers from a minute size up to 6 or 8 cm. or more
in diameter; the large ones rarely exceed 3 to 10 mm. in
thickness.

UPPER CAMBRIAN.
St. Charles limestone [Walcott, 1908a, p. 6]:

1, Dark, bluish-gray, and gray limestone in layers varying from 1 54b, 54¢, 54d. 54r, 329a.
to 20 inches in thickness. Many of the layers are almost made 25 feet below the top: Eoorthis desmopleura—4r.
up of flattened concretions varying from a minute size to 6 or 8 Lingulella manticula—54h. | Syntrophia nundina—329a.
(Gil se pocabotadeeasecsecnesissesoosmmamn besaecacadecooncoor sacs 190 Eoorthis desmopleura—s4b. :

Syntrophia nundina—b54b.
Dicellocephalus—54b.

105 to 125 feet below the top:
Schizambon typicalis—54c.
Boorthis desmopleura—54c.
Eoorthis newberryi—4c.
Syntrophia nundina—d4c.
Solenopleura—b4e.
Menocephalus—54e.
Tllznurus—54e.

20 to 30 feet above base:
Lingulella (Lingulepis)

acuminata—4d.
ELoorthis desmopleura—54d.
Eoorthis newberryi—54d.
Agnostus—54d.
Solenopleura—54d.
Menocephalus—54d.
Asaphus?—54d.

2a. Massive-bedded dark lead-gray arenaceous clifi-forming
limestone, becoming thinner bedded in the lower 50 feet. 195

2b. Massive-bedded gray arenaceous limestone with a few irregu-
lar cherty layers which extend down 85 feet, just below
which the dark arenaceous limestone for a thickness of
about 15 feet is almost made up of round concretions 2 to 4
isshany HAL GHENT Koso a soe mmc one atoaderoneaaaSsoscoSSSseasa55 100

2c. Gray siliceous and arenaceous limestone in layers one-half 54j.
inch to 6 inches thick, occurring in massive bands. Light- Obolus (Westonia) iphis—54j.
gray chert fills large and small annelid borings, and it also Lingulella desiderata—54j.
occurs as flattened stringers in the line of the bedding and
iin (OO JEN/OUS.. 5 o59-Seccnsee ssecessoscusseasoesscoosessccne= 85

2d. Massive-bedded arenaceous limestone, forming broken cliffs.

A few cherty nodules occur near the top, and the lower 50
feet has many irregular oval cherty nodules and stringers of
chert coincident with the bedding. ..-..........-.---.------ 397

DETAILED STRATIGRAPHIC DISTRIBUTION.

149

Detailed stratigraphic distribution of Cambrian and Ordovician Brachiopoda—Continued.

Utah: Blacksmith Fork, Cache County—Continued.

Blacksmith Fork section.
[ Walcott, 1908f, pp. 190-200.]

Localities and species in
the Blacksmith Fork
section.

Other localities and species in
Utah and Idaho shown in
their approximate
graphic position.

strati-

UPPER CAMBRIAN—Continued.

St. Charles limestone—Continued. Feet.
3. Bedded bluish-gray fossiliferous limestone.........-.-.---.-------- 94 | 31m, 31n, 54e, 55h. 4y, 5a, 5c, 30q, 30s, 54t, 54w,
Upper part: 54x,
A crotreta sp.—31n. Obolus rotundatus—30q.
Anomocare—31n. Obolus tetonensis ninus—i4w.
Near base: Obolus wortheni—da, 5c, 54t, 54w,
Obolus sp. undt.—3lm, 54x,
55h. Obolus (Westonia) ella—4y.
Lingulella manticula—31m.| Lingulella desiderata—ia, 54t.
Billingsella coloradoensis— | Lingulella isse—30s.
31m, 55h. Lingulella manticula—30q.
Agnostus—31m, 55h. A crotreta idahoensis—ic, 54t.
Ptychoparia—31m, 55h. Acrotreta idahoensis sulcata—54t.
Anomocare—55h. Billingsella coloradoensis—4y, 5a,
A mixture of the faunas at 54t, 54x.
the base and at the top: | Agnostus—54w, 54x.
Obolus discoideus—od4e. Ptychoparia—54t, 54w, 54x.
Obolus? sp. undt.—d4e. Liostracus—54w, 54x.
Lingulella manticula—b4e. | Anomocare—54t, 54w, 54x,
Billingsella coloradoensis— | Damesella sp.—54w, 54x.
54e. Ptychaspis—54w, 54x.
Huenella lesleyi—i4e.
Hyolithes—54e.
Cyrtolites—i4e.
A gnostus—54e.
Ptychoparia—4e.
A nomocare—d4e.
4, Bedded light-gray sandstone, followed below by dirty-brown sand- 54f, 54¢. 34q, 54u, 56g.
stone and toward the base ’shaly and thin-bedded sandstone. - 166 | In upper 20 feet: Obolus discoideus—56g.
—| Obolus discoideus—s4f. Obolus meconnelli pelias—34q.
Total Upper Cambrian (St. Charles limestone). ....-..-----.- 1, 227 Obolus (Fordinia) bellulus | Obolus wortheni—54u.
5 —d4f. Acrotreta idahoensis—54u, 56g.
Acrotreta idahoensis alta— | Acrotreta idahoensis alta—34q.
54f. Billingsella coloradoensis—54u,
Billingsella coloradoensis— 56g.
54f. Platyceras—56¢.
Near the base: A gnostus—54u, 56g.
Lingulella (Lingulepis) | Ptychoparia—54u, 56g.
acuminata—4g. A nomocare—54u.
Ptychaspis—54u.
MIDDLE CAMBRIAN.
Nounan limestone [Walcott, 1908a, p. 6]:
la. Light-gray arenaceous limestone. -..-.-.-..------------------- 12 A few traces of fossils occur | 56f?.
1b. Lead-colored arenaceous limestone 40 in the lower 28 feet and | Obolus matinalis—56f.
1c. Light-gray arenaceous limestone. - ..- - 85 large annelid borings occur | Lingulella manticula—s6f.
1d. Dark lead-gray arenaceous limestone. ..-...--.---------------- 87 in many of the arenaceous | Orthotheca—s6f.
le. Shaly and thin-bedded arenaceous limestone with intercalated limestones. In the dark | Agraulos—s6f.
reddish-brown sandy layers. - Selo rock the irregular borings | Ptychoparia—o6f.
lf. Light-gray arenaceous limestone. - - . - 18 are filled with lighter-col- | Anomocare—s6f.
1g. Dark lead-gray arenaceous limestone. 2-- 198) ored rock, and in the light- | A nomocarella—o6f.
1h. Light-gray arenaceous limestone. -.........---.--------------- 494 gray rock by darker rock. | Solenopleura—béf.
li. Dark lead-gray arenaceous limestone, with numerous irregular -
annelid borings filled with light-gray arenaceous limestone.. 56
1j. Massive-bedded arenaceous cherty limestone. --.------------.- 8
ik. Bluish-gray cherty more or less arenaceous limestone in thick
bands that break up into thin layers on weathering. ......- 28
— 1,041
Bloomington formation: 311, 54h. $3j, 329.
la. Thin-bedded bluish gray compact limestone with interbedded Protospongia (spicules)—54h. | Obolus (Westonia) ella—329.
thick layers of gray limestone. .........-------------------- 22 uolus meconnelit pelias— | Obolus (Westonia) wasatchensis—
54h. 33], 329.
Obolus (Westonia) wasatch- Biajlboaunse quadrans—329.
ensis—54h. Olenoides wasatchensis—329.
Lingulella desiderata—311,
54h.
Hyolithes—54h.
A gnostus—81 1, 54h. t
Ptychoparia—54h.
1b. Greenish argillaceous shale..........-.-..--------------------- 12
1c. Gray coarse-grained limestone. -....---..---.----------------- 13 55m.

Hyolithes—55m..
Ptychoparia—55m.

CAMBRIAN BRACHIOPODA.

Detailed stratigraphic distribution of Cambrian and Ordovician Brachiopoda—Continued.

Utah: Blacksmith Fork, Cache County—Continued.

Blacksmith Fork section.

Localities and species in

Other localities and species in

Utah and Idaho shown im

[Walcott, 1908f, pp. 190-200.] ue ee lacksmith Fork their approximate strati-
5 graphic position.
MIDDLE CAMBRIAN—Continued.
Bloomington for mation—Continued. ‘ Feet.
1d. Greenish argillaceous and sandy shale...............----.----- 147 55k. y
Hyolithes (fragments)—55k.
A gnostus—55k. ©
Ptychoparia—s5k.
le. Gray coarse-grained limestone ............-.-.-.-------------- 4 54i.
Micromitra sculptilis—54i.
Hyolithes (abundant)—654i.
Piychoparia—b4i.
A graulos—54i.
lf. Greenish argillaceous and sandy shale.............--..-------- 22
220
2a. Bluish-gray limestones, with small concretions and small 31j.
nodules of calcite scattered through the layers, which range Fragments of fossils—31j.
from an inch to 6 inches or more in thickness. ----.---.--.-- 380 U
2b. Mosive:betued gray limestone that forms a low cliff and breaks 55s. ;
own readily on gentle slopes. .-.--.--.--------------------- 132 Ptychoparia. .
Agraulos. Same asin le.
2c. Bluish-gray limestone, with small concretions and small nodules 381i.
of calcite scattered through the layers; a limestone similar Hyolithes—s1i.
LO oe Mee Soe aa Rah EBD acd ab SB o Sa eoS Tannen erbaeeees 290 A graulos—sli.
2d. Greenish argillaceous shale.-.........-.-- sore soessousonsssosss 39 54k. 5h?, 32x, 38t, 54a, 55d?.
Obolus (Westonia) wasatch- | Micromitra (Iphidella) pannula?
ensis—d4k. —54q.
A graulos—s4k. Obolus sp. undt.—54q.
Piychoparia—54x. Obolus (Westonia) ella—5h.
Obolus (Westonia) wasatchensts—
32x, 33t, 54q, 55d.
Acrothele subsidua—d4q.
Nisusia alberta—54q.
Nisusia alberta ?—54q.
2e. Bluish-gray thin-bedded limestone..-.-......-.--------------- 182
2f. Arenaceous steel-gray limestone. -._.-----.-.-.------------.---- 22
2g. Bluish-gray limestone, with small concretions and small 31h, 55n. $e 54y.
nodules of calcite scattered irregularly through the layers... 55 Micromitra sculptilis—31h, | Obolus wortheni—bd4v.
— 1,100 55n. Ptychoparia, 2 species—54v.
——| Ptychoparia—sih, 55n.
Total of Bloomington formation. .......-.-.------------------ 1,320 | Dorypyge—alh, 55n.
Blacksmith limestone [Walcott, 1908a, p. 7]:
la. Dark lead-gray arenaceous limestone-....---.-------.---.----- 195
1b. Arenaceous steel-gray cliff-forming limestone, in the lower por- 31g. i
tion passing gradually into a dove-gray compact limestone Fragments of a small trilo-
that weathers to a light-gray color. The layers vary in bite (Ptychoparia ?)—31g.
thickness from 4 inches to 2.5 feet....-.-..--.--------------- 375 Annelid borings—slg.
Total of Blacksmith limestone. .---....-.-.-.------------------ 570

Ute limestone [Walcott, 1908a, p. 7]:
la. Bluish-gray compact thin-bedded limestone, with large irregu-
lar annelid borings in the upper part filled with steel-gray
arenaceous limestone similar to the beds above. Below, the
limestone is puter and more uniformly gray and in layers
that tend to form low cliffs on the steeper slopes. .--.-.-..--

54m.
In upper part:
Micromitra (Paterina) la-
bradorica utahensis—
54m.

Billingsellasp. undt.—54m.

Hyolithes—54m.

Agraulos—54m.

Ptychoparia subcoronata—
54m.

Dorypyge? quadriceps—

54m.

DETAILED STRATIGRAPHIC DISTRIBUTION. 151

Detuiled stratigraphic distribution of Cambrian and Ordovician Brachiopoda—Continued.

Utah: Blacksmith Fork, Cache County—Continued.

Blacksmith Fork section.
[Walcott, 1908f, pp. 190-200.)

Localities and species in
the Blacksmith Fork
section.

Other localities and species in
Utah and Idaho shown in
their approximate strati-
graphie position.

MIDDLE CAMBRIAN—Continued.

Ute limgstone—Continued.
1b. Gray arenaceous limestone in thin layers, with a few bands of Feet.
layers 4 to 10 inches thick, often oolitic, and with interfor-
mational conglomerate and flattened concretions-.-.-..--.-- 135

31c, 540, 550.

In the upper 5 feet:
Scenella—sio.
Ptychoparia subcoronata—

5.

50.
Dorypyge? quadriceps—
550.
In layers 70 to 80 feet below
the top:

Micromitra (Paterina) la-
bradorica utahensis—54o.

Obolus mcconnelli—3ic.

Acrotreta cf. ophirensis—
3le.

Acrotreta sp. undt.—31e.

Billingsella coloradoensis—
540.

Otusia utahensis—31ce.

Eoorthis zeno—81c, 540.

Syntrophia cambria—3ic,
540.

Hyolithes—540.

Scenella—54o.

Zacanthoides—31c.

Ptychoparia subcoronata—
3le, 540.

Dorypyge? quadriceps—

80u, 32e, 32n, 34m.

Micromitra (Paterina) labradorica
utahensis—30u, 34m.

Obolus (Westonia) ella ?—32n.

Acrotreta cf. ophirensis—30u.

Syntrophia cambria—22e, 34m.

dle, 540.
1c. Gray limestone, with numerous concretions one-fourth to one-
half inch in diameter. A few thin layers of interforma-
tional conglomerate and some shaly limestone. ...........-- 58
— 483
Sle, 54a. 3830p, 31z, 32y, 55t, 329c?.
2a. Gray, fine-grained, calcareous and argillaceous shaly beds..... 38 Micromitra (Paterina) labra- | ‘fiecromitra (Paterina) labrador-
dorica utahensis—54a. ica utahensis—30p.
Obolus (Westonia) ella—3le, | Obolus meconnelli—30p.
54a. Obolus (Westonia) ella—30p, 32y,
j Acrothele turneri?—54a. 55t, 329¢.
Tsoxys cf. argentea—54a. Acrothele subsidua?—55t.
Ptychoparia—38le, 54a. Acrotreta ophirensis—81z, 55t.
2b. Bluish-gray to blue-black, fine-grained, thin-bedded limestone. 57 Obolus ?.
Ptychoparia.
2c. Greenish argillaceous and calcareous shale, weathering: buff.... 51
2d. Thin-bedded grayish-blue limestone -.....-....-..-.-.--.----- 36
54n.
2e. Gray oolitic limestone in layers 3 to 14 inches thick ....-...... 24 Micromitra (Paterina) stu- &
arti—54n.
Micromitra (Paterina) su-
perba—54n.
Hyolithes—54n.
Ptychoparia a—54n.
Ptychoparia b—54n.
Dorypyge (fragment )—54n.
54p, : 8ly?.
2f. Greenish argillaceous and sandy shale...........-.-...-.--...- 18 Micromitra (Paterina) su- | Obolus meconnelli—3ly.
erba—b54p. Lingulella isse—31y.
Obolus meconnelli—54p.
Ptychoparia sp. undt.—54p.
54y. 59g.
2g. Bluish-gray thin-bedded limestone..-...-.-....-..-----.----- 22 Micromitra (Paterina) su- | Lingulella sp.—59g.
— 246 erba—b4y. Acrothele subsidua—d9g.

wolithes—54y .
Ptychoparia (small heads)—
b4y.

Acrotreta cf. idahoensis—d9¢g.
Microdiscus—59¢.
Ptychoparia, 3 species—d9g.
Neolenus—59g.

Zacanthoides idahoensis—59z.
Menocephalus—59g.

—
On
iS)

CAMBRIAN BRACHIOPODA.

Detailed stratigraphic distribution of Cambrian and Ordovician Brachiopoda—Continued.

Utah: Blacksmith Fork, Cache County—Continued.

Blacksmith Fork section.

Localities and species in

Other localities and species
Utah and Idaho shown

in
in

[Walcott, 1908f, pp. 190-200.] oe oe aceon Fork: | iheie approximate six abil
‘ graphic position.
MIDDLE. CAMBRIAN—Continued.
Ute limestone—Continued. 31d, 541. 32c, 32d, 32p, 55c, 55e, 163.

2h. Spence shale member [Walcott, 1908a, p. 8]. (Greenish argillaceous Feet.
BMaVol SemaVGhy SOMES) 56 Ames osteo csnoeoeebasetestouesheoneneb sss 30

MotalyofsUtellimes tone meee eee eee eee eee eee ee 759

Micromitra (Iphidella) pan-
nula—541.

Oborus (Westonia) ella—31d,
54

Lingulella desiderata—541
Hyolithes—541.

Orthotheca major—541.
Leperditia—54\.
Ptychoparia—-31d, 541.
Bathyuriscus productus—541.

Eocystites ? longidactylus—55e.

Micromitra (Paterina) labrador-

ica utahensis—32d.

Micromitra (Iphidella) pannula—

5dc, 55e.

Obolus (Westonia) ella—32d, 55e.

Lingulella desiderata—55e.

Acrothele subsidua—32p, 55c, 55e,

163.
Acrotreta definita—55e, 163.

Acrotreta idahoensis sulcata—55e

163.
Acrotreta cf. ophirensis—32c.

Nisusia (Jamesella) nautes—5de

163.

Nisusia (Jamesella) spencei—55e

163.
Agnostus—5be, 55e, 163.
Microdiscus—55e.
Ptychoparia piochensis—55e.
Ptychoparia—sise, 163.

Zacanthoides idahoensis—5dec, 55e

163.
Zacanthoides sp.—ic.
Neolenus a—s5e.
Neolenus b—55e.
Olenoides—5ic.
Bathyuriscus howelli—sie.
Bathyuriscus productus—55e.
Ogygopsis—s5e.
Oryctocephalus reynoldsi—siec.
Oryctocara geikiei—hic.
Hyolithes—5ie.

Langston limestone [Walcott, 1908a, p. 8]:
la. Massive-bedded bluish-gray limestone passing downward into
gray arenaceous limestone, with many round concretions
SR UG) $e shaYe Ort CLEI WE a5 choc ssonSnneecocresecosseasonencoeS

(%)

Obolus (Westonia) ella.
Zacanthoides sp.
Bathyuriscus productus.
Neolenus?.

5b, 54s, 59f, 322, 322a.
Micromitra haydeni—54s.

Micromitra (Iphidella) pannula—

54s, 59f.

Micromitra (Iphidella) pannula

maladensis—54c.

Micromitra (Iphidella) pannula

ophirensis—4s.
Lingulella desiderata—d4s, 59f.
Lingulella helena—54s.
Lingulella isse—5As.
Acrothele artemis—54s.
Acrothele subsidua—i4s.
Acrothele subsidua var.—d4s.

Acrotreta idahoensis sulcata—54s,

3222.

Acrotreta pyxidicula—ds, 59f, 322.

Acrotreta?—o4s.

Acrothyra minor—d4s.
Billingsella coloradoensis—54s.
Hyolithes—54s.
Orthotheca—i4s.
Stenotheca—S4s, 59f.
Platyceras—s4s.

A agnostus—ds.
Microdiscus—i4s, 322a.
Solenopleura—bas, 59f.

Ptychoparia, 2 species—54s, 59f

3228.
Oryctocephalus—54s.
Dorypyge, 2 species—S4s.
Neolenus, 2 species—54s, 59f.
Asaphiscus—a4s.
Ogygopsis ?—4s.
A graulos—59f.
Anomocare—59f.
Zacanthoides—59f.

1b. Massive-bedded bluish-gray limestone that breaks up into lay-
ers 2 to 8 inches thick on weathering and with many round
COUCTE LIONS Bee esse eee eee nee eee eee eer eee
108

55p.
Ptychoparia—iip.
Bathyuriscus productus—5ap.

2. Massive-bedded dark arenaceous limestone, passing at about 150
feet down into a calcareous sandstone and then a gray sandstone - 390

Motaliofelangstonilimestoness assess -seee eee se eee nt 498

Brigham quarizite [Waleott, 1908a, p. 8]:
la. Quartzitic sandstone, gray-greenish, gray-brownish, dirty
gray, allweathering reddish dirty brown, in layers 3 inches
to!3 feet in thickness. 2-2... J. - 2-2 -- ce. n tne nn-------

’

DETAILED STRATIGRAPHIC DISTRIBUTION.

153

{
Detailed stratigraphic distribution of Cambrian and Ordovician Brachiopoda—Continued.

Utah: Blacksmith Fork, Cache County—Continued.

Blacksmith Fork section.

Localities and species in

Other localities and species in
Utah and Idaho shown in

[Walcott, 1908f, pp. 190-200.] the oe iacksmith = Fork | their approximate strati-
3 | graphic position.
MIDDLE CAMBRIAN—continued.
Brigham quarizite—Continued. Feet. 56r.
Home Greenishwhardisandy Shaler. scesccce cen =e ce nseace esas 4 Annelid trails—55r.
Trilobite tracks—55r.

lem Sameyasulon (GS timated) seseece oe eee soe eee eee ase 1, 200+

MotalkomBrmshamiquantzitesesecs seas seeeeees -aeeeee eee ee 1,232

Total Middle Cambrian @ 5, 420+

Motall Cambrian aes ceet esses aae yascusceet cate t eee eee 6, 647+

Utah: House Range, Milla:

rd County.

House Range section.
{ Walcott, 1908f, pp. 173-185.]

Localities and species in the
House Range section.

Other localities and species in
Utah and Nevada shown in
their approximate strati-
graphic position.

The House Range section lies east and west of Antelope Springs and east-
southeast and south of Marjum Pass, House Range, Millard County, Utah. It
begins at the top of Notch Peak, the highest point on the House Range south of
Marjum Pass.

ORDOVICIAN. 105t. 34g.
Feet. | Obolus (Westonia) notchen- | Eoorthis desmopleura—s4g.
Banded thin-bedded bluish-gray and purplish limestone resting con- sis—105t.
formablyson\thel Cambrian secrets sss 2a- ose. snes snes eee ema see 285 | Hoorthis desmopleura—105t.
Raphistoma sp., ete.—105t.
UPPER CAMBRIAN. 31q, 30w, 30x. 331.
Lingulella isse—31q. Eoorthis desmopleura—83 1.
Notch Peak limestone [Walcott, 1908a, p. 9]:° Dikellocephalus? sp.?—31q. | Solenopleura—33 1.
la. Gray arenaceous limestone in thick layers and bands of thin In drift bowlders: Illenurus ?—33 1.
layers. Irregular nodules and thin layers of dark-gray chert Eoorthis desmopleura—
weathering dark brown occur at irregular intervals for 350 30w.
feet below the summit. A few thin cherty layers 4 to 4 inch Schizambon typicalis—30w.
ThickgalsOVoccuMubelowe «oe --erm-casesee eee cee eeee acres 640 Agraulos—30w.
Solenopleura—30w.
Tllznurus—30w.
Crepicephalus—30x.
Ptychoparia—30x.
1b. Shaly dark-gray to bluish-gray arenaceous limestone, with
small dark concretions in some layers.............-..------- 90
,
ic. Gray siliceous limestone in layers of varying thickness, 4 inches
to 2 feet, banded with dark cherty layers and purer arena-
ceous limestone. The chert takes the form of flattened
nodules and very thin irregular layers.........-......------ 340
id. Shaly and thin-bedded bluish gray arenaceous limestone... - 65
le. Gray siliceous limestone in layers 2 inches to 2 feet thick. The 30m.
lower part, where not metamorphosed, is dove-colored and in Obolus tetonensis leda—30m.
layers 6 inches to 3 feet thick, with some gray cherty matter Fragments of the free cheek
in flattened nodules and thin layers that weather a dark of a trilobite—30m.
DEON ilseesreootocasastoa sooaeanaos ec aanaee cdonneCabeoseanesas 355
Motalloi;Notch) Peak: limestone:-2- 52 -sss2-ee-se] eee aa= == === 1, 490
Orr formation [ Walcott, 1908a, p. 10):
la. Bluish-gray to gray compact limestone in layers 1 inch to 2 feet Fragments of trilobites.
thick. On weathering, the thicker layers break down into
thin irregular layers which form a talus of angular frag-
WIGMIS6 » Gasdccsecqspebss sOHASHOE SSE conseeesbouseomeosaaeasS 375
1b. Sandy and siliceous bluish and drab-colored shales, with inter- 301, 30y. 32f.
bedded bands of dark bluish-gray limestone 6 inches to 2 feet Section of crinoid column— | Lingulella manticula—32f.
HONG coosvie son eeeeeceersecsecs eee Sacoceceos eee se UE eoaonete 84 30 1. Lingulella perattenuata—32.

Obolus rotundatus—30y.
Lingulella isse—30y.
Lingulella manticula—301.
A nomocare—301, 30y.
Ptychaspis—301.

Lingulella pogonipensis—32

@ The line of separation between the Middle and Lower Cambrian occurs somewhere in the Brigham quartzite, and this thickness (5,420 feet)

probably includes several hundred feet of Lower Cambrian beds.
b Section expesed on the east and southeast slopes and ridges of Notch Peak.

c The section is carried along the strike of the exposed strata 2 miles east to the west side of Orr Ridge, where the rocks of the Orr formation

are unmetamorphosed.

154

CAMBRIAN BRACHIOPODA.

Detailed stratigraphic distribution of Cambrian and Ordovician Brachiopoda—Continued.

Utah: House Range, Millard County—Continued.

House Range section.
[Walcott, 1908f, pp. 173-185.]

Localities and species in the
House Range section.

Other localities and species in
Utah and Nevada shown in
their approximate strati-
graphic position.

UPPER CAMBRIAN—Continued.

Orr formation—Continued. Feet.
1c. Lead-colored finely oolitic and arenaceous limestone in layers
4 inches to 2 feet thick, obscurely banded by thin strips of
lighitzandidankyprayicololLseeeese ease rere eee eee ee eee 91

Fragments of trilobites.

1d. Bluish-gray compact limestone in layers 2 inches to 4 feet thick
that break down into irregular thin layers on weathering... 115

le. Dirty-brown and bluish-black arenaceous shales, with thin
nodules of gray fossiliferous limestone in some horizons; also
Bey layers of bluish-gray limestone 4 inches to 8 inches
thick: 350s She ee ee ee ig. Se Reece emee 235

Sit.

Linnarssonella modesta—31t.
Linnarssonella nitens—31t.
Solenopleura—sit.

30j, 30k.

Micromitra (Paterina) cre-
nistria ?—30}.

Obolus meconnelli pelias—30j.

15d, 32g, 32t, 33d, 33n?, 34i,
341, 34t, 329d2.
bolus meconnelli pelias—32g,

— 900 | Lingulella desiderata—30}. Obolus rotundatus—33d, 34i, 34r.
Lingulella isse—30j, 30k. Lingulella desiderata—15d, 32g,
Linnarssonella modesta—30k. 34i.
Linnarssonella transversa—- | Lingulella isse—15d, 32g, 33d, 34r,
30). 34t.
A gnostus—30j. Lingulella manticula—15d.
Crepicephalus—30j. Schizambon typicalis—33d.
Ptychoparia?—30k. Linnarssonella girtyi—32t.
Solenopleura—30k. Linnarssonella nitens—32g.
Fe Acrotreta idahoensis—15d.
Acrotretaidahoensis alta—15d, 33n.
Acrotreta marjumensis—33d.
Acrotreta pyxidicula—329d.
A gnostus—33d, 34t.
Agraulos—33d.
Menocephalus—32g.
Ptychoparia—st.
Ptychoparia ? sp.—32g, 33d, 34r.
Solenopleura—32g, 34t.
Ptychaspis—32t.
2a. Gray slightly arenaceous cliff-forming limestone in layers 2 to 30h, 30i.
6 feet thick, weathering lead gray...........-..-.-.--------- 590 Lingulella desiderata—30h.
Acrotreta idahoensis—30h.
A graulos—30i.
Crepicephalus teranus—30h.
Bathyuriscus—30h.
Tilenurus ??—30h.
2b. Gray limestone and dark-gray chert in alternating layers 3 to
2inches thick. Theirregularcherty layers weather in reliefas
dark-brown bands and the limestone as lead-colored bands,
which give a very characteristic banded appearance to the
CLR She see oe eae ee eae eaters se eee an Seige 170
2c. Gray arenaceous limestone in massive beds that usually break Traces of trilobites and
up, on weathering, into irregular layers } to 4 inches thick. brachiopods,
The upper 20 feet form a more massive solid bed than the
IBV ELSIDElOW sasecee em eae Seren Cee nn ree ee Nae 165 oo
=—_ pas)

Total of Orr formation

Totali@ipper: Cambrian a: -— ss sseee sc eee eee eee ee nee eee es

MIDDLE CAMBRIAN.

Weeks limestone[ Walcott, 1908a, p. 10]: =
la. Thin-bedded limestones in layers 1 to 4inches thick. The lime-
stone is mainly fine grained, dark gray, and weathers lead col-
ored, except on bedding planes, where it is usually more or
lessipinkishe eB sss sis seeds ons Sa ae oe ee erase ae 245

Fragments of trilobites and
brachiopods of the fauna
in shaly limestone in 1b.

1b. Shaly limestone, usually dark gray, with pinkish tinge in some
layers and on the surfaces; sometimes buff yellow on weath-
ering. The shales vary from } to 1 inch thick. This is a
marked band in some sections and is arbitrarily separated
fromithe;shalyabedsibelowaesceeeee eee ee ee eee eee eee 285

300.

The fauna ranges through
about 100 feet of the lower

ortion of this division.

Obolus ( Fordinia) perfectus—
300.

Agnostus, 2 species—300.

Piychoparia—300.

Crepicephalus texanus—30o.

Anomocare—300.

Bathyuriscus—30o.

A saphiscus sp.—300.

Solenopleura—300.

@ Section exposed at Weeks Canyon from beneath the massive limestone on the south side of the canyon to the top of the cliffs on the south side

of Marjum Pass. Average dip, 12°; strike, N. 20° E. (magnetic).

DETAILED STRATIGRAPHIC DISTRIBUTION

Detailed stratigraphic distribution of Cambrian and Ordovician Brachiopoda—Continued.

Utah: House Range, Millard County—Continued.

House Range section.
[Walcott, 1908f, pp. 173-185.]

Localities and species in the
House Range section.

Other localities and species in
Utah and Nevada shown in
their approximate strati-
graphic position.

MIDDLE CAMBRIAN—Continued.

Weeks limestone—Continued.
1c. Shaly bluish-gray to dark-gray limestone in layers 4 to 1 inch
thick, with occasional layers 2 to 6 inches thick; 25 feet from
she top a band of layers of arenaceous dirty-gray finely
oolitie li

bandvesiteetibelow-res- «stu. ons. oe cee Sac uemenioseoeee eon le 170

mestone 3 feet thick occurs, and a second similar Feet.

30n, 30n’.
Lingulella isse—30n, 30n’.

Obolus (Fordinia) perfectus—-

30n, 30n’.

Acrotreta ophirensis—30n,
30n’.

Acrotreta ophirensis descen-
dens—30n, 30n’.

Hyolithes—30n, 30n’.

Agnostus (several species )—
30n, 30n’.

Ptychoparia (several
cies)—30n, 30n’.

Crepicephalus teranus—30n,
30n’.

Solenopleura—30n, 30n’.

Asaphiscus sp.—30n, 30n’.

Neolenus—30n, 30n’.

spe-

1d. Reddish-tinted more or less arenaceous shaly limestone....... 30

Same as le, but not abun-
dant.

le. Shaly bluish-gray to dark-gray limestone, similar to le......_- 270

Same as that of Ie.

if. Evenly bedded bluish-gray to dark-gray fine-grained lime-
stone, in layers 2 to 16 inches thick, with shaly limestone

A few traces of Agnostus and
Piychoparia similar to

TORI S20 asco ks te nae SE eee eBAAECaE Poser aomcrermactaae 330 those above.
1g. Calcareous shales with thin layers of limestone.....-...-....-- 60
Total thickness of Weeks limestone. .-........-.-------------- 1,390
Marjum limestone [ Walcott, 1908a, p. 10]:¢
la. Gray, more or less thin-bedded limestone that weathers dark 10y, 10z, 11n, 1lo. 15p, 15x, 34v, 329b?.
lead gray and breaks down into angular fragments 4 to 2 In upper 100 feet: Obolus meconnelli pelias—15p,
inches thick. Flattened cherty nodules and thin irregular Obolus meconnelli pelias— 15x, 34v.
cherty. layers\occur at intervals: _--....._.2.5-.-.-.-.------- 305 lin. Lingulelia desiderata—15p, 15x.
Obolus (Fordinia) gilberti— | Dicellomus politus—329b.
11n. Ptychoparia—34v.
Acrotreta bellatula—11n.
Acrotreja marjum ensis—
lin.
Acrotretacf. sagittalis—11n.
Agnostus, 4 species—lIn.
Central portion:
Micromitra sculptilis—l0y.
Lingulella arguta—l0y.
Dicellomus prolificus—10z.
Acrotreta attenuata—l0y.
Acrotreta bellatula—10z.
Agnostus—l0y, 10z.
Ptychoparia—10y , 102.
Anomocare—l0y, 10z.
Near base:
Micromitra (Iphidella)
pannula ophirensis—11o.
Choltes meconnelli pelias—
0.
Obolus rotundatus—1lo.
Hyolithes—11lo.
Stenotheca—11o.
Piychoparia—1lo.
Anomocare—llo.
Bathyuriscus—11o.
1b. poeruating bands of dark blue-gray compact limestone in Ptychoparia sp. undt.
massive layers that break up into thin irregular layers, and
gray arenaceous limestone in layers 1 to 8 inches thick.
Gray limestone lene seactemcss Aicccsaas eee cone é 35
2. Blue-gray limesto 7
3. Gray arenaceous limestone. 95
4. Blue-gray limestone......_. 12
5. Gray arenaceous limestone. 52590,
‘6B lue-eray,limestoneusesee sm: oe ene se sens senna eeeeeeneees 8
— 247

a Section exposed in the cliffs southeast of Marjum Pass and in the ridge east of Wheeler Amphitheater.

CAMBRIAN BRACHIOPODA.

Detailed stratigraphic distribution of Cambrian and Ordovician Brachiopoda—Continued.

Utah: House Range, Millard County—Continued.

House Range section.
[Walcott, 1908f, pp. 173-185.

Localities and species in the
House Ranye section.

Other localities and species in
Utah and Nevada shown in
their approximate strati-
graphic position.

MIDDLE CAMBRIAN—Continued.

Marjum limestone—Continued. Feet.
1c. Dark and light-gray thin-bedded limestone, more or less arena- 3w, 11lq, lly, 30g, 30z.
Peas eo kao cuusccsnodsedee Ss opseaee 250 Near top:
Acrotreta pyxidicula—30z.
A qgnostus—30z.
Ptychoparia like P. kingi—
302.
In central portion, though
ranging through 100 to
150 feet of the thin-
bedded shaly limestone:
Obolus meconnelli pelias—
1lq, 30g.
Lingulelia arguia—3w,liq,
lly.
Acrothele subsidwa—liq,
30g.
Acrotreta ophirensis?—lly,
30g.
Nisusia (Jamesella) nau-
tes—ll1q.
Nisusia (Jamesella)
spencei—11q.
Hoorthis thyone—11q.
Hyolithes—30¢.
A qnostus, 2 species—30g.
Ptychoparia, 3 species—
30g.
Solenopleura—30¢g.
Neolenus inflatwus—il1q,
30g.
Neolenus intermedius—
11q, 30¢.
Neolenus intermedius pu-
gio—11q, 30g.
Neolenus superbus—i1q,
30g.
Ogygopsis P—11q, 30g.
id. Gray analy, limestone passing below into shales interbedded in 3x, 8y, 8i, 11x.
the shaly limestone, and at 75 feet from the top into drab Micromitra (Iphidella) pan-
ATAULACeOUSySh al CS Bee er ee ese ese e nese ee raat teaer 105 nula ophirensis—3x.

Micromitra sculptilis—3x, 8i.
Obolus meconnelli pelias—
8x, 8i.
Obolus rotundatus—3x, 11x.
Lingulella arguta—3x, 11x.
Acrotreta attenuata—3x.
Acrotreta ophirensis—8x, 3y.
Acrothele subsidua—3x.
Acrothele subsidua levis—3x.
Hoorthis remnicha—3x.
Eoorthis thyone—3x
Syntrophia unria—3x.
Agnostus, 3 species—3x.
Ptychoparia—3x.
Neolenus inflatus—3x.
Neolenus intermedius—3x.
Neolenus superbus—3x.
Ogygopsis?—s8x.

‘tw, 14v?, 15c, 32k, 34s?.

Obolus meconnelli—l4y, 32k, 34s.

Nisusia (Jamesella) nautes—1ie.

Nisusia (Jamesella) utahensis—
Tw.

Anomocare—15c.

Ptychoparia—32k.

3e.

Micromitra (Iphidella) pannula
ophirensis—8e.

Micromitra sp.—e.

Obolus matinalis—se.

Obolus tetonensis—3e. -

Lingulella arguta—se.

Acrothele subsidua levis—8e.

Acrotreta ophirensis—se.

Acrotreta ophirensis rugosa—se.

Ptychoparia—3e.

Neolenus sp.—se.

Agnostus sp.—se.

le. Dark bluish-gray limestone in thick beds that break up on
weathering into thin, irregular layers 4 to 2 inches thick .-....

Total thickness of Marjum limestone ......-...-.-.-.---------

1lp.

Sponge spiculee—11p.
Linnarssonella sp.—11p.
A gnostus—11p.
Ptychoparia—11p.
Ogygopsis—11p.

Wheeler formation [Walcott, 1908a, p. 10]:

1. Alternating bands of thin shaly limestone and calcareous shale,
with shale gradually increasing and predominating toward the
lower portion. At 405 feet from top a band of blue-gray hard
limestone, in layers 4 to 2 inches thick, occurs. At 473 feet
another band, and below an occasional thin layer......-.......-

3s, 8t, 4, 8g, 1lu, 15b.
Obolus mcconnelli pelias—3s,

3t, 8g.
Acrothele subsidua—ss, 3t,
4, 8g, 11u, 15b.

Acrotretaattenuata—8s, 3t, 8g.

Agnostus bidens—3s, 3t, 8g.

Asaphiscus wheeleri—3s, 3t,
8

ig.
Ptychoparia kingi—s, 3t, 8g.

8k?. ‘
Obolus meconnelli pelias—8k.

a Section exposed at Marjum Pass, but the type locality isin Wheeler Amphitheater, southeast of Antelope Springs.

south from the ridge south of the lower springs of Antelope Springs.

The section was measured

DETAILED STRATIGRAPHIC DISTRIBUTION.

157

Detailed stratigra phic distribution of Cambrian and Ordovician Brachiopoda—Continued.

Utah: House Range, Millard County—Continued.

House Range section.
[Walcott, 1908f, pp. 173-185.]

Localities and species in the
House Range section.

Other localities and species in
Utah and Nevada shown in
their approximate strati

graphic position.
MIDDLE CAMBRIAN—Ccontinued.
Swasey formation [ Walcott, 1908a, p. 11): 4 Feet.
la. Oolitic and arenaceous limestone in massive layers near the 80b, 31w.
top. Below, some dark bluish-gray limestone is interbedded, Near the top:
and gradually it becomes the principal rock; it breaks up on Platyceras—31w.
weathering into irregular shaly layers 3 to 3 inches thick ..--. 152 Zacanthoides—31w.
Near the base:
Scenella—30b.
Zacanthoides—30b.
Ptychoparia—30b.
Dorypyge—s0vv.
1b. Drab and reddish argillaceous shales, with interbedded thin
layers of fossiliferous limestone...................-..------- 63
1c. Dark bluish-gray limestone in massive layers that break up into
irregular shaly layers } to 2 inches thick............-....... 17
id. Calcareous and argillaceous shales, with thin layers of gray lime- llw, 30c.
RUDE Oso seedocobes Sacqdeus ROT Gar OES aS aeRen anos See Seo nEmenGos 102 Micromitra (Paterina) labra-
dorica utahensis—30c.
Lingulella arguta—l11w.
Ptychoparia, 2 species—llw,
30c.
le. Bluish-gray limestonein layers 4 to 10 inches thick, with numer- 30d. 34u?.
ous concretions from } to 1 inch in diameter in a few layers-.- 6 Obolus (Westonia) ella—30d. | Obolus (Westonia) wasatchensis—
—— Ptychoparia, 3 species—30d. 34u.
Total of Swasey formation.....-..............------------ 340

Dome Canyon limestone [Walcott, 1908a, p. 11]:

Massive-bedded cliff-forming gray siliceous limestone, with small specks
ofcalcite. 100 feet from the top and for 50 feet below some layers
of brownish-yellow arenaceous limestone 15 inches to 2 feet thick
WECUP sid shanoudarho-deqae San aepne RAORE MBA sae eNmaanmeeansrese as

Howell formation [ Walcott, 1908a, p. 11]: ¢
la. Bluish-black limestone in massive layers that break up on
weathering into irregular thin layers.............-.---.-----

3l1v.

Micromitra (Iphidella) pan-
nula—3lv.

Acrotreta cf. ophirensis—31v.

Ptychoparia—31v.

14t?, 33r?,

Micromitra (Iphidella) pannula—
14t.

Lingulella cf. similis—14t.

Acrotreta neboensis—14t.

Otusia utahensis—33r.

toa Grayesiliceouspimestones-seerer cosa] = eee neato eee eee 8
1c. Bluish-black limestone similar to la -....-.......---.--------- 105
1d. Pinkish-colored argillaceous shale, with interbedded thin 31s. 3d, 11s, 32h, 32j, 32z, 33f.
lay.ersfotlimestones=n meen ase ann tes o- sas se cn ckoe eee easeecs 10 Micromitra (Iphidella) pan- | Micromitra sculptilis—11s.
nula—3ais. Micromitrasp.—3d.
Obolus (Westonia) ella—3ls. Micromitra (Paterina) labradorica
‘Acrotretaci. ophirensis—31s. utahensis—3d.
Scenella—als. Obolus (Westonia) ella—3d, 11s,
Hyolithes—31s. 32h, 322.
Zacanthoides—als. Obolus (Westonia) ella onaquien-
Bathyuriscus—als. sis—33f.
Acrotreta cf. ophirensis—32j.
Olenoides?—3d.
Bathyuriscus sp.—82h, 322.
le. Gray siliceous limestone in layers 2 to 10 inches thick.-..._..- 70
1f. Bluish-black limestone in massive layers, breaking up into thin 30f.
layersionl weathering=s. see esele seen essences coe neoeeeee 102 Ptychoparia—30f.

Bathyuriscus—30.

a Section exposed on the southwest ridge of Swasey Peak.

> Section exposed in the central portion of Dome Canyon and adjoining cliffs.

¢ Section exposed on the west face of the House Range at Howell Mountain.

158

CAMBRIAN BRACHIOPODA.

Detailed stratigraphic distribution of Cambrian and Ordovician Brachiopoda—Continued.

Utah: House Range, Millard County—Continued.

House Range section.
[Walcott, 1908f, pp. 173-185.]

Localities and species in the
House Range section.

MIDDLE CAMBRIAN—Continued.

Howell formation—Continued.
lg. Gray siliceous limestone in thick beds......--..--.------------

Other localities and species in
Utah and Nevada shown in
their approximate strati-
graphic position.

55u.
fic omiine (Iphidella) pannula—
ou

Linnarssonella urania—55u.

ih. Pinkish argillaceous shale, which is believed to be the same as
the Spence shale member of the Ute limestone of northeastern
Utah, is exposed on the east side of Dome Canyon a little

8v.
Micromitra (Iphidella) pan-
nula—3v.

8c, 7k, 30a, 31, 3lu, 320, 34n2,
329e, 333, 383a, 333b.
Micromitra (Iphidella) pannula—

3iu,

above where it bends to the westward..........-.---------- 20 Obolus (Westonia) ella—3v. 30a, 31, 333.
— Lingulella dubia—3v. Obolus meconnelli—34n .
Motalrotsdoywelldonm ahloneerer ener secs eeesseee eases eine 455 | Acrothele subsidua—s3v. Obolus (Westonia) ella—8e, 30a,
Hyolithes billingsi—3v. 31, 31u, 320, 329e, 333, 338a, 333b.
Piychoparia piochensis—3v. Lingulella dubia—31, 333.
Ptychoparia sp.—sv. Lingulella helena—30a.
Zacanthoides typicalis—3v. Hyolithes billingsi—30a, 31, 31u.
Bathyuriscus productus—3v. | Isoxys argentea—30a.
Eocystites longidactylus—31, 31u,
333.
Ptychoparia kempi—333b.
Ptychoparia piochensis—31, 31u,
333a, 333b.
Ptychoparia quadrans—30a.
Anomocare parvum—3sl.
Bathyuriscus howelli—21, 31u, 333,
| _ 338a, 333b.
Bathyuriscus productus—30a, 31,
31u, 333, 333a.
Zacanthoides grabaui—333b.
Zacanthoides typicalis—31,
333, 333b.
Langston (?) limestone [Walcott, 1908a, p. 8]: @
1a. Massive-bedded bluish-gray arenaceous limestone, with irregu- 30e.
lar partings of buff-colored arenaceous limestone. The lat- Billingsella sp. undt.—30e.
ter penetrates the layers of limestone in the most irregular Platyceras—s30e.
manner and frequently surrounds small irregular nodules Hyolithes—a0e.
of the bluish-gray limestone............--------------------- 170 Leperditia—30ve.
Ptychoparia—a0e.
Zacanthoides—30e.
Dorypyge?—sa30e.
1b. Brown buff-weathering arenaceous limestone in thick layers;
almost sandstone in places. ........-..---------------------- 35
Total of Langston (?) limestone.....-...-...------------------ 205
MotaleMid dlet@ ama brie see see ee eee ele er 4,417
LOWER CAMBRIAN.
Pioche formation [Walcott, 1908a, p. 11] :
Arenaceous and siliceous shaly layers, with some thicker layers of Annelid trails. 41, 30, 31a, 33i, 313¢.
Quartziticisandstone je) jo6 (oe. enene arene ene ee 125 | Trilobite tracks ( Cruziana). TE (Iphidelia) pannula—
41, 30, 3la.
Obolus (Westonia) ella—33i.
Acrothele spurri—3la.
Acrothele subsidua hera—3la.
Acrotreta clayioni—4 1.
Acrotreta primxva—4], 3a.
Billingsella highlandensis—30, 31a...
Billingsella sp.—313¢g.
Nisusia (Jamesella) erecta—313g.
Hyolithes billingsi—31a.
Callavia nevadensis—20, 3132.
Olenellus fremonti—30, 313g.
Olenellus gilberti—30, 31a.
Peachella iddingsi—30, 313g.
Zacanthoides levis—3la.
Crepicephalus augusta—a0, 31a.
Crepicephalus liliana—30, 31a.
Oryctocephalus primus—3la.
Prospect Mountain quartzite [Walcott, 1908a, p. 12]:¢
Gray and brownish quartzitic sandstone in layers 4 inches to 3 feet
ial MAHAN 52 coco snes ocwec ons ao one posooeeoSEssecoctoosecossees 1, 375+
Gianiell ayer Chisel pV. 3.5555 sceesocgaesossceodes ssepsesssocssoessse855 1, 500+
ANA Ohnta EN = saccoses een cose boao soebanceososeoorsscasesaonscescude 9, 232

a This sectionof beds which are doubtfully referred to the Langston was measured at the same locality as the shale forming 1h of the Howell
formation, which is believed to be equivalent to the Spence shale member of the Ute limestone of northeastern Utah.

b Section exposed at the westward bend of Dome Canyon.

ce Section exposed on the west slope and foothills of the House Range north and south of Dome Canyon.

HABITAT. 159

Detailed stratigraphic distribution of Cambrian and Ordovician Brachiopoda—Continued.
Vermont.

The localities in Vermont are somewhat scattering, but most of them are confined to a fairly well-marked horizon
in the Lower Cambrian. Two (319f and 227) occur in the Ordovician, four (28, 16n, 87’, and 319q) in the Upper Cam-
brian, and two (28a and 319s) in the Middle Cambrian. The interrelations of these localities (see index for num-
bers) are obscure and’ stratigraphic comparisons would have little value.

Virginia and Maryland.

All but two of the localities in Maryland and Virginia (see index for numbers) occur in the same Lower Cambrian

sandstone horizon. One Upper Cambrian locality (92b) and one Middle (47h) have been identified.
Wales.

See England, Scotland, and Wales, where the different horizons are more or less closely differentiated and corre-
lated, with complete lists of localities and included species.

Wisconsin, Michigan, Minnesota, and Iowa.

Two localities (339 and 364a) from the Lower Ordovician Oneota dolomite and three (328b, 339a, and 364) from the
Upper Cambrian St. Lawrence formation have been identified by Sardeson [1896, pp. 95 and 96]. The remainder are
from the ‘‘St. Croix sandstone,’’ and have all been referred to the Upper Cambrian, with the following exceptions:
79x, 83', 84, 84f, 84s, 328e, 328g, 339e, 339i, 339j, and 339k. These eleven localities occur in the lower portion of the
“St. Croix sandstone’’ and while they may belong in the Upper Cambrian, they have been placed in the Middle
Cambrian because of the entire absence in the collections at our disposal of characteristic Upper Cambrian forms.

Wyoming. c

See both South Dakota and Montana for general discussion of stratigraphy.

HABITAT.

The conditions in which the Cambrian brachiopods are found indicate that some of them
were gregarious in habit, and that many persisted through marked changes of environment and
sedimentation. Micromitra ([phidella) pannula, for instance, is found in sandstone, siliceous
and argillaceous shale, and limestone. It has a wide distribution in the.Cordilleran province of
western North America, and has a vertital range of 2,000 feet or more. Other forms, such as
Micromitra haydeni, are known only from one locality and one layer of rock. A large
number of species occur in sandstone and shales that are evidently of shallow-water origin;
others occur in limestones that were probably deposited in relatively deep water. The evidence
indicates that their habitat largely ranged from between tides to a depth of 1,000 to 2,000 feet.
Some forms may have had a greater bathymetric range, but the evidence in favor of such a
conclusion is not known to me.

Tn the following list there has been brought together a summary statement of the character
of the sediment in which each of the genera taken up in this monograph occurs. Gradations
from one type of sediment to another are so frequent and close that some of the separations may
be considered arbitrary, though most of the determinations have been made by an examination
of the hand specimen upon which the species is preserved. The numbers in the columns give |
the number of species occurring in the different classes of sediment and the number which have
been identified from more than one class. The totals at the end of the table give the number of
species and the number of genera, respectively, that have been identified from the different
sediments.

It is probable that a reexamination of some of the specimens would justify their transfer to
another column; for instance, the one sandstone representative of the genus Huenella might be
found to occur in a calcareous sandstone or arenaceous limestone, which might equally as well
be placed in the limestone column; but the table as a whole and the figures for each genus seem
to indicate that the various genera are by no means confined to nor even characteristic of a given
type of sediment. On the other hand, a similarly prepared table of the species in the mono-
graph showed that with few exceptions each of the species is confined to one type of sediment.
Disregarding those species (about 200) which have been found at but one locality, the table
showed that out of over 500 specific occurrences only 150 had been identified from more than
one type of sediment. Errors in the identification of sediment would be of more importance in
the latter case than in that of the genera, but none of the specimens were reexamined and in
none of the tables has there been any rearrangement of the figures.

160 CAMBRIAN BRACHIOPODA.

List of genera and subgenera, alphabetically arranged, giving number of species occurring in the different types of sediment.

Limestone
Genera. Limestone.| Shale. | Sandstone. and
sandstone.

Limestone | Shale and

and shale. | sandstone. | 4! three.

Acrothele sc; sah sceen id sclnce = se steeaatee Mee eeeeeee eee eee
(Redlichella).......-..-...-
ENCLOUMYM Ase =n pee ciciseiae

Botstondiae fesse: ene eee
Glarkella sen else ee eee
Clinticiataeceeeene==eeaeenee se
Dearbormiaeees eeeesseeee see ae
DElvadella ee ee aes
DicellomuUsseseseseeee eee ees
Discinolepis-......--.----------
Discinopsis
Elkania. - -
Eoorthis. - -
Hostrophom
Finkelnburgia.
Helmersenia -
Huenella....-
WKY SOLD BIA eee eee ace wits aise ete eyetel se ets See ee ae ee eee Eee «crete Baas
IKGUIGOL PINGS ooo Seapets are tars se ab iaie siele iets Semaine ee eee eens an 4
Mingle laser. Hee wea a ees ace oe cise e aac eee ee af 35
(@epiembolon) Bese erase eee neers al Peseneaceeon| eneueiicss
(@aingulepis) Seere esse asece osteo ccnee ce eee eeeee Bs
hinnarssonellasere ss peeaeseeee ees ee eee eee eee eee ee
MUG KeWwitziatrseccen ecm e cee wenn cane eee saan eae Bete eee | ele ae eee
MicrOmi basse eee eernt seta ee enn eee eects
(ACME) nec pansanesseaneaesss -pessogsecesooa5
IP aberin a) eee ae see cance nase cen uae ce ae aaa
NEO DOLUSEe rer cesar cmc emiaee cote a one eee eee ee
INSRUE none ce cos danpoassuonseHnouooesbobocbedudoauicd
(Giamiesell ai) te se a ane TS SRS
Olga ees --sncensscspeooseesacacmasoss2cusdsceseos

wo
Dw
oD
Or

(CACHING) aap dad scumsceHeadeacroleceeueoeterenoade
(Brogperia) =. i255 i oeen sens eae one eee eon wacenene
(Mor dimi bh) isa sa rae 2S eee eee ene
(@iingulo bolus) Beese esses as ee ee eee eee eeee een
(CMbickayatzella) a9 ees eee eee ee se wena oem
pecnea aia) speconsn

(Westonia)
Orbiculoidea.
Orusia-
Otusia-
Philhedra. -

URIS tella seme sree ere ee eee cet ere tal et es
Schizamabontrs eet eee ee eee eee
SIMA O) NON sss asossessssceor Syaoecoesedoeoosoce
Schuchentin ayes eee ws eee ee ene eee ee
Siphonotretiat en eee ascetic sae eee anes
Seite na Sh oc escen peor eRensanusAaveseocenoeES
Siymtro phi ae sey eo See oe eae cere poe oneal
Trematobolus...-...-- BO BSNaucOD Aa eM bo RRs onaet
Volborthia
Wimanella
Wynnia-... Z
FYIOT Lae eee ea eee eto cee eee S eee ae ee a Mee er

Generas.y. 6 eres cece saints aoe Ree eee eee 44 33 50 21 14 14 18
SPECIES! ais 2 Se A 3 Nee oes eee ge clare 310 199 240 44 50 28 33

LOCALITIES.

The following list gives all known data concerning all localities from which fossils described
in this paper have been obtained. After most of them reference is given to the pages on which
their stratigraphic position is shown (pp. 124-159). Those that are without references are more or
less isolated places for which stratigraphic data are lacking and which are without near neighbors
to which they may be profitably compared. An asterisk (*) placed before the name of a species
indicates that the place from which it is cited is its type locality. In localities 1-227 and
C1—C75 the Brachiopoda are not accompanied-by author names, but for purposes of identifica-
tion the author names follow all other listed species. In localities 300 to 396z all the listed
species are accompanied by a reference to either the place of citation or the museum in
which the specimens are located. In all lists the Brachiopoda are placed first.

Numbers 1-227 were assigned to the different localities represented in the United States
National Museum at the time of their accession and indicate distinct faunules. Numbers

LOCALITIES. 161

C1-C75 (pp. 286-291) were assigned to the faunules collected by the expedition to China of the
Carnegie Institution of Washington. Numbers 300-396z (pp. 229-286) have been arbitrarily
assigned to localities mentioned in the literature or unnumbered localities in the United States
National Museum collections, and the included species may not occur together as do those of
the former localities. For each of the species listed in localities 300—396z it is simply true that
the description of the locality under which it is placed gives all available information as to its

stratigraphic and geographic position and the authority for so listing it.

Localities 1-227, U. S. National Museum.

1 (about 50 feet above Ja).
zone A of No. 7 of the Manuels Brook section [ W:

(For stratigraphic position and association, see p. 140.)

Middle Cambrian: Shales of
alcott, 1891b, p. 261], Manuels Brook, a small stream which

flows into Conception Bay from the east, near Topsail Head, Newfoundland (0. D. Walcott, 1888).

*Obolus fragilis.
Lingulella ferruginea.
Lingulella ferruginea?.
Acrothele matthewi.
Acrotreta misera.

Walcott [1891b, p. 261] cites the following additional
Hyolithes sp. a.
Agnostus 3 sp.

Conocoryphe matthewi (Hartt).
Paradoxides hicksi Salter.
Paradoxides sp.

Anopolenus venustus Billings.
Erinnys venulosa Salter.

species:
Conocoryphe elegans (Hartt).
Agraulos socialis Billings.

Microdiscus punctatus Salter.

Liostracus tener (Hartt).

la (=6n and 61, about 50 feet below1). (For stratigraphic position and association, see p. 140.) Middle Cambrian:

Shales-near the top of No. 6 of the Manuels Broo
tion Bay, Newfoundland (C. D. Walcott, 1888).
Obolus fragilis.
Lingulella ferruginea.
Acrothele matthewi.
Agraulos socialis (Billings).

11 (same horizon as lv). (For stratigraphic position

k section [Walcott, 1891b, p. 261], Manuels Brook, Concep-

Liostracus tener (Hartt).
Conocoryphe elegans (Hartt).
Paradoxides davidis Salter.
Paradoxides sp.

and association, see p. 138.) Lower Cambrian: Shales of

No. 3 of the Silver Peak group, Barrel Spring section [Walcott, 1908f, p. 1894], 2.5 miles (4 km.) south of
Barrel Spring and 0.5 mile (0.8 km.) east of road, in the extreme southeastern corner of the Silver Peak
quadrangle (U. 8. G. 8.), Esmeralda County, Nev. (F. B. Weeks, 1899).

Acrothele spurri?.
Acrotreta claytoni.

1m (=1p). (For stratigraphic position and association

Ptychoparia sp.
Olenellus gilberti Meek.

, See p. 138.) Lower Cambrian: Limestones of No. 2 of the

Silver Peak group, Barrel Spring section [Walcott, 1908i, p. 189], about 2.5 miles (4 km.) south of Barrel
Spring and 0.5 mile (0.8 km.) east of the road, in the extreme southeastern corner of the Silver Peak quad-
rangle (U.S. G.8.), Esmeralda County, Nev. (F. B. Weeks, 1899).

Micromitra (Paterina) prospectensis.
Nisusia (Jamesella) argenta.

1p (1m, which see). (For stratigraphic position and
Micromitra (Paterina) prospectensis.
* Nisusia (Jamesella) argenta.

lv (same horizon as 11). (For stratigraphic position

Olenellus gilberti Meek.

association, see p. 138.) (F. B. Weeks, 1899.)
Olenellus fremonti Walcott.
Olenellus gilberti Meek.

and association, see p. 138.) Lower Cambrian: Shales of

No. 3 of the Silver Peak group, Barrel Spring section [Walcott, 1908f, p. 1892], 3 miles (4.8 km.) north of

Valcalda Spring and 4 miles (6.4 km.) west-no:

rthwest of the Drinkwater mine, Silver Peak quadrangle

(U.S. G. S.), Esmeralda County, Nev. (F. B. Weeks, 1899).

Archzocyathus.

*Micromitra (Paterina) labradorica var.
Kutorgina cingulata.

*Kutorgina perugata.

*Siphonotreta? dubia.

*Sywantonia weeksi.

2. (For stratigraphic position and association, see p.

Manuels Brook section [Walcott, 1891b, p. 261]

Walcott, 1888).
Obolus fragilis.

Swantonia sp.

Stenotheca cf. elongata Walcott.
Stenotheca cf. rugosa (Hall).
Ptychoparia sp.

Wanueria gracile Walcott.
Olenellus argentus Walcott.

140.) Middle Cambrian: Shales of zone B of No.7 of the
, Manuels Brook, Conception Bay, Newfoundland (C. D.

Acrothele matthewi.

Lingulella ferruginea.

aThe species mentioned by Walcott [1908f, p. 189] occur at slightly different localities (11 and lv), none of the species being common to

both localities.
62667°—vot 51, pr 1—12——11

162 CAMBRIAN

Walcott [1891b, p. 261] cites the following:
Linnarssonia misera=Acrotreta misera.
Orthis sp.
Stenotheca sp.
Agnostus punctuosus Angelin.
Agnostus 5 sp.
Microdiscus punctatus Salter.
Paradoxides davidis Salter.
Paradoxides hicksi Salter.
Paradoxides sp.

BRACHIOPODA.

Anopolenus venustus Billings.
Conocoryphe elegans (Hartt).
Ctenocephalus matthewi (Hartt).
Erinnys venulosa Salter.
Ptychoparia robbi Hartt.
Ptychoparia variolaris Salter.
Holocephalina inflata Hicks.

| Agraulos socialis Billings.

2a (same horizon as 1). (For stratigraphic position and association, see p. 140.) Middle Cambrian: Above
and to the north of the limestone, in the shales of the Paradowxides zone, Topsail Head, Conception Bay,

Newfoundland (C. D. Walcott, 1888).
Lingulella ferruginea.

2b. Lower Cambrian: Limestone just north of Beman Park, in the northeastern part of the city of Troy, Troy
quadrangle (U. S. G. 8.), Rensselaer County, N. Y. (H. E. Dickhaut, 1899).

Micromitra (Paterina) labradorica.
Bicia gemma.
*Bicia whiteavesi.

Obolella crassa.
Botsfordia ceelata.
Billingsella salemensis.

2d. Lower Cambrian: Arenaceous limestone in the knobs just east of Beman Park and southwest of Brunswick,
near Troy, Troy quadrangle (U. 8. G. 8.), Rensselaer County, N. Y. (H. E. Dickhaut, 1899).

Obolella crassa.

2e (see 3b). (For stratigraphic position and association, see p. 132.) Middle Cambrian: Shale 25 feet (7.6 m.)
above the basal quartzite, Seeley Street, St. John, St. John County, New Brunswick (S. W. Loper, 1899).

Protorthis billingsi. :

2f (3 feet below 2g; see 308e). (For stratigraphic position and association, see p. 133.) Middle Cambrian: Sand-
stones of Division 1b1 of Matthew’s [1895a, p. 108] Protolenus zone, Hanford Brook, St. John County,
New Brunswick (C. D. Walcott and S. W. Loper, 1899). ‘

*Lingulella martinensis.
Acrothele prima.

2g (3 feet above 2f and underlying 2h; see 308e).

*Acrotreta inflata.
Acrotreta sagittalis transversa.

(For stratigraphic position and association, see p. 133.) Middle

Cambrian: Sandstones of Division 1b1 of Matthew’s [1895a, p. 108] Protolenus zone, Hanford Brook,
St. John County, New Brunswick (C. D. Walcott and 8. W. Loper, 1899).

Lingulella martinensis.
*Acrotreta inflata.

Acrotreta sagittalis.

| Acrotreta sagittalis transversa.

Matthew cites the following additional species from Division 1b1:

‘Acrothele matthewi? (Hartt).

*Acrothele matthewi prima Matthew=Acrothele prima.

*Hipponicharion eos Matthew.
Beyrichona tinea planata (Matthew).

2h (overlying 2g; see 301). (Forstratigraphic position and association, see p. 133.) Middle Cambrian: Sandstones
of Division 1b2 of Matthew’s [1895a, p. 108] Protolenus zone, Hanford Brook, St. John County, New
Brunswick (C. D. Walcott and 8. W. Loper, 1899).

Lingulella martinensis.
Trematobolus pristinus.
Acrothele prima.

*Acrothele prima costata.
Acrotreta sagittalis transversa.

Matthew cites the following additional species from Division 1b2:

Beyrichona tinea Matthew.
*Beyrichona tinea planata (Matthew).
Beyrichona rotundata Matthew.

Beyrichona ovata Matthew.
Indiana secunda Matthew.

2i (underlying 2k). (For stratigraphic position and association, see p. 132.) Middle Cambrian: Sandstones of
Division 1b3 of Matthew’s [1895a, p. 108] Protolenus zone, Hanford Brook, St. John County, New Bruns-

wick (C. D. Walcott and 8. W. Loper, 1899).

Lingulella ferruginea?.
Lingulella martinensis.
Botsfordia sp.
Trematobolus pristinus.

Acrothele prima.

Acrothele prima costata.
Acrotreta sagittalis magna.
Acrotreta sagittalis transversa.

LOCALITIES. 163

Matthew cites the following additional species from Division 1b3:

Bradoria benepuncta (Matthew). Beyrichona tinea Matthew.

Bradoria minor (Matthew). Beyrichona tinea planata (Matthew).
*Bradoria cambrica (Matthew). *Beyrichona tinea triangularis (Matthew).
Bradoria oculata (Matthew). Beyrichona papilio (Matthew).

Indiana lippa (Matthew). *Beyrichona rotundata Matthew.

Indiana secunda pyriformis (Matthew). *Hipponicharion minus Matthew.
Walcottella fusiformis (Matthew). *Hipponicharion cayatum Matthew.

2k (just above 21). (For stratigraphic position and association, see p. 132.) Middle Cambrian: Sandstones of
Division 1b3 of Matthew’s [1895a, p. 108] Protolenus zone, Hanford Brook, St. John County, New Bruns-
wick (C. D. Walcott and 8. W. Loper, 1899).
Trematobolus pristinus.
Acrothele prima costata.
Acrotreta sagittalis transversa.

Matthew cites the following additional species from this locality:
Indiana secunda pyriformis (Matthew).
Beyrichona tinea Matthew.

21 (underlying 2m). (For stratigraphic position and association, see p. 132.) Middle Cambrian: Limestone at the
base of the Paradoxides zone [Matthew, 1895a, p. 108], Hanford Brook, St. John County, New Brunswick
(S. W. Loper, 1899).
Lingulella ferruginea.
Acrothele matthewi.
Acrothele matthewi multicostata.

Acrotreta sagittalis magna.
Protorthis billingsi.
*Koorthis hastingsensis.

Matthew cites the following additional species from the base of the Paradoxides zone at this locality:
Beyrichona tinea Matthew.

2m (overlying21). (Forstratigraphic position and association, see p. 132.) Middle Cambrian: Shales near the base
of the Paradowides zone [Matthew, 1895a, p. 108], Hanford Brook, St. John County, New Brunswick
(S. W. Loper, 1899).
Lingulella ferruginea. Protorthis billingsi.
Acrothele matthew. : Eoorthis hastingsensis.

2n. Lower Cambrian: Limestone bowlders in conglomerate along the shore of the St. Lawrence, near Trois
Pistoles, Temiscouata County, Quebec, Canada (C. D. Walcott, 1899).
*Micromitra (Paterina) bella.
*Micromitra (Paterina) logani.

20 (see 2p and 2r). Lower Cambrian: Limestone bowlders in conglomerate on shore at east entrance to harbor at
Bic, Rimouski County, Quebec, Canada (C. D. Walcott, 1899).

Micromitra (Paterina) bella. Botsfordia ceelata.
Micromitra (Paterina) labradorica. Yorkia wanneri?.
Bicia gemma. Nisusia festinata.
Kutorgina cingulata. Discinella sp.

Obolella crassa.

» 2p (see 20 and 2r). Lower Cambrian: Limestone on south side of the road a little west of Bic and half a mile
(0.8 km.) west of the road leading to the wharf, Rimouski County, Quebec, Canada (C. D. Walcott, 1899).

Bicia gemma.

Botsfordia ceelata.

2r (see 20 and 2p). Lower Cambrian: Limestone bowlders in a conglomerate in a cut on the Intercolonial Rail-
way, 2 miles (3.2 km.) west of Bic railway station, Rimouski County, Quebec, Canada (C. D. Walcott,

1899).
*Micromitra nisus: Botsfordia celata.
Micromitra (Paterina) labradorica?. Callavia bicensis Walcott.

2s (see 2t). (For stratigraphic position and association, see p. 132.) Middle Cambrian: Limestone in upper part
of Paradorides zone, at Hastings Cove [see Matthew, 1898b, p. 38], on Kennebecasis Bay, 0.5 mile (0.8 km.)
northeast of Torryburn, on the Intercolonial Railway, northeast of St. John, St. John County, New Bruns-
wick (C. D. Walcott, 1899).

Lingulella ferruginea. Acrotreta sagittalis.
Acrothele matthewi. *Acrotreta sagittalis magna.
Acrothele matthewi multicostata. Billingsella coloradoensis.

* A crotreta gracia. Billingsella sp.

Acrotreta misera, Eoorthis hastingsensis.

164 CAMBRIAN BRACHIOPODA.

Matthew cites the following additional species from this locality:
Indiana primzva (Matthew).
Indiana dermatoides (Walcott).

2t (shale in which limestone of 2sisinterbedded). (For stratigraphic position and association, see p. 132.) Middle
Cambrian: Shales in upper part of Paradowides zone, at Hastings Cove [see Matthew, 1898b, p. 38], on
Kennebecasis Bay, 0.5 mile (0.8 km.) northeast of Torryburn, on the Intercolonial Railway, northeast of
St. John, St. John County, New Brunswick (C. D. Walcott, 1899).
*Acrothele matthewi multicostata.
Acrotreta misera.

2u (below 2x; see 308g). (For stratigraphic position and association, see p. 132.) Middle Cambrian: Lowes
beds exposed on the south side of Long Island, Kennebecasis Bay [see Matthew, 1898a, pp. 124 and 127],
St. John County, New Brunswick (C. LD. Walcott, 1899).
Trematobolus kempanum.
* Protorthis helena.
Protorthis (Loperia) dugaldensis.

2x (=locality given by Matthew [1892, p. 59]; a higher horizon than 2u). (For stratigraphic position and associa-
tion, see p. 131.) Upper Cambrian: Thin-bedded sandstones of Division 2 of Matthew [1892, p. 59], on the
south shore of Long Island, Kennebecasis Bay [see Matthew, 1898a, pp. 124 and 127], St. John County
New Brunswick (C. D. Walcott, 1899).

*Lingulella minor.
Lingulella minor?.
Lingulella (Lingulepis) starri.

gy. (or stratigraphic position and association, see p. 133.) Middle Cambrian: Sandstone about 25 feet (7.6 m.)
above the Lower Cambrian, on the southeast side of Catons Island, in Long Reach, St. John River, Kings
County, New Brunswick (C. D. Walcott, 1899).
Botsfordia pulchra.

2z. (for stratigraphic position and association, see p. 147.) Middle Cambrian: Nolichucky(?) shale [Campbell,
1899, p. 3], near Shipley Ferry, 0.75 mile (1.2 km.) northwest of Bethany Chapel, northeastern comer of
the Son Mountain quadrangle (U. S. G. S.), Sullivan County, Tenn. (M. R. Campbell, 1894).
Dicellomus appalachia.

22’. (For stratigraphic position and association, see p.147.) Middle Cambrian: Shales in the Honaker limestone
[Campbell, 1899, p. 3], at Wallace switch, about 5 miles (8 km.) northeast of Bristol, Bristol quadrangle
(U. 8. G. S.), Sullivan County, Tenn. (T. C. Mendenhall and M. R. Campbell, 1894).
Dicellomus appalachia.

3 (highest horizon on Manuels Brook). (For stratigraphic position and association, see p. 140.) Upper Cambrian:
Shaly limestones 300 feet (91.4 m.) above the Paradoxides zone, Manuels Brook, Conception Bay, New-
foundland (0. D. Walcott, 1888).

Lingulella ferruginea. Acrotreta sagittalis transversa.
Acrothele matthewi. Orusia lenticularis.

3a. Lower Cambrian: 450 feet (137.1 m.) below the quartzite in the St. John formation and over 500 feet (152.4
m.) below the Protolenus fauna of Matthew [see Walcott, 1900, pp. 320-322], Hanford Brook, St. John
County, New Brunswick (C. D. Walcott, 1899).
Micromitra (Paterina) labradorica.

3b (see 2e). (For stratigraphic position and association, see p. 132.) Middle Cambrian: Shale at the base of the
Paradoxides zone, head of Seeley SUH, St. John, St. John County, New Brunswick (S. W. Loper, 1899).
Acrothele matthewi.
Protorthis billingsi.
Protorthis quacoensis.

3c. (For stratigraphic position and association, see p. 158.) Middle Cambrian: Shales about 75 feet (22.9 m.
above the quartzitic sandstones of the Cambrian, at Ophir, Oquirrh Range, Tooele County, Utah (H. E.
Dickhaut, 1900).

Obolus (Westonia) ella.

3d. (For stratigraphic position and association, see p. 157.) Middle Cambrian: Concretionary limestone about
100 feet (30.5 m.) above the quartzitic sandstones of the Cambrian, at Ophir, Oquirrh Range, Tooele
County, Utah (H. E. Dickhaut, 1900).
Micromitra sp. Obolus (Westonia) ella.
Micromitra (Paterina) labradorica utahensis. Olenoides?.

)

LOCALITIES. 165

8e. (For stratigraphic position and association, see p. 156.) Middle Cambrian: Thin-bedded limestone less than
400 feet (121.9 m.) above the quartzitic sandstones of the Cambrian, at Ophir, Oquirrh Range, Tooele
County, Utah (H. E. Dickhaut, 1900).

Micromitra sp. *Acrothele subsidua levis.
* Micromitra (Iphidella) pannula ophirensis. *Acrotreta ophirensis.
Obolus matinalis. *Acrotreta ophirensis rugosa.
Obolus tetonensis. Olenoides?.

Lingulella arguta.

3g (see 360h). Middle Cambrian: Shales on river bank 250 feet (76.2 m.) above west end of Denver and Rio
Grande Railway tunnel, Glenwood Springs, Garfield County, Colo.
Obolus (Westonia) ella.
Lingulella sp.

3h. (For stratigraphic position and association, see p. 181.) Upper Cambrian: Shale and shaly limestone, on
McNeil Brook, 1.5 miles (2.4 km.) east of Marion Bridge, Cape Breton, Nova Scotia (S. W. Loper, 1900).
*Obolus acadicus. Lingulella ferruginea.
Obolus (Bréggeria) salteri. Schizambon priscus.
Lingulella concinna.

3i. (For stratigraphic position and association, see p. 132.) Middle Cambrian: Compact, fine-grained, thin-bedded
gray sandstone of the Paradoxides zone, on McLean Brook, 1 mile (1.6 km.) east of McCodrum Brook and
1.5 miles (2.4 km.) west of Marion Bridge, Cape Breton, Nova Scotia (S. W. Loper, 1900). Matthew [1903,
p- 195] says the horizon is his Division €2b.
*Lingulella cania.
Lingulella concinna.
Lingulella ferruginea.

Lingulella rotunda.
*Lingulella (Lingulepis) exigua.
Acrothyra proavia.

3j (same locality as 5j, but 25 feet above; see 4v and 4q). Middle Cambrian: Above the quartzitic sandstones, in
a shale corresponding in position to the upper part of shale No. 6 of the Dearborn River section [Walcott, ,
1908f, p. 202], about 6 miles (9.6 km.) west-northwest of Scapegoat Mountain, on the Continental Divide
between Bar Creek and the headwaters of the south fork of the North Fork of Sun River, Coopers Lake
quadrangle (U. S. G. S.) Powell County, Mont. (C. D. Walcott, 1905).
Obolus mcconnelli.
Bathyuriscus productus (Hall and Whitfield).

$n. (For stratigraphic position and association, see p. 131.) Upper Cambrian: Thin-bedded sandstone on Salmon
River, Gillis Hill, 13 miles (20.9 km.) south of Marion Bridge, eastern Cape Breton, Nova Scotia (S. W.
Loper, 1900).
Lingulella minor. *Acrotreta convexa.
Lingulella (Lingulepis) exigua.

80 (see 372c). (For stratigraphic position and association, see p. 131.) Upper Cambrian: Shales in the first
ravine south of the post office at Barachois, east of Little Bras d’Or Lake, eastern Cape Breton, Nova Scotia
(S. W. Loper, 1900).
Lingulella concinna.

8p. (For stratigraphic position and association, see p. 131.) Upper Cambrian: Shales in ravine 0.5 mile (0.8 km.)
north of McMullins, on the crossroad to Boisdale station, eastern Cape Breton, Nova Scotia (S. W. Loper,
1900).
Lingulella concinna.

8q. (For stratigraphic position and association, see p. 131.) Upper Cambrian: Shale in Barachois Glen, 4 miles
(6.4 km.) south of Little Bras d’Or Lake, eastern Cape Breton, Nova Scotia (S. W. Loper, 1900).
Obolus (Bréggeria) salteri. Schizambon priscus.
Lingulella concinna. Acrotreta bisecta.

3s (same horizon as 1z, 4, and 15b; =3t and 8g). (Forstratigraphic position and association, see p. 156.) Middle
Cambrian: About 1,700 feet (518.2 m.) above the Lower Cambrian and 2,700 feet (823 m.) below the Upper
Cambrian, in the shaly limestones and calcareous shales of the Wheeler formation [Walcott, 1908f, p. 181], in.
the eastern part of Wheeler Amphitheater, east of Antelope Springs, House Range [Walcott, 1908f, Pls. XIII |
and XV], Millard County, Utah (C. D. Walcott, F. B. Weeks, and L. D. Burling, 1903 and 1905).

Obolus mcconnelli pelias. Ptychoparia kingi (Meek).
Acrothele subsidua. Ptychoparia sp.
Acrotreta attenuata. Asaphiscus wheeleri (Meek).

Agnostus bidens (Meek).

166 : CAMBRIAN BRACHIOPODA.

3t (=8s, which see). (For stratigraphic position and association, see p. 156.)

8v. (For stratigraphic position and association, see p. 158.) Middle Cambrian: About 200 feet (61 m.) above the
Lower Cambrian in the ‘Spence shale’’ [ Walcott, 1908f, p. 183] (described in this monograph, p. 158, as
lh of the Howell formation), in Dome Canyon, about 5 miles (2 km.) west of Antelope Springs, House
Range [Walcott, 1908f, Pl. XIII], Millard County, Utah.
(See p. 158 for list of species.)

3w (same horizon as 30g and 1lq). (For stratigraphic position and association, see p. 156.) Middle Cambrian:
About 2,350 feet (716.3 m.) above the Lower Cambrian and 2,050 feet (624.8 m.) below the Upper Cambrian, \
in the central portion of the thin-bedded limestones forming Ic of the Marjum limestone [Walcott, 1908f,
p. 180], in the cliff about 2 miles (3.2 km.) southeast of Marjum Pass, House Range [see Walcott, 1908f,
Pls. XIII and XV], Millard County, Utah (C. D. Walcott, 1903).
Lingulella arguta. Ptychoparia.
Acrotreta bellatula. Neolenus.

3x (=llx). (For stratigraphic position and association, see p. 156.) Middle Cambrian: About 2,200 feet (670.6
m.) above the Lower Cambrian and 2,200 feet (670.6 m.) below the Upper Cambrian, in the limestones forming
1d of the Marjum limestone [Walcott, 1908f, p. 180], 2.5 miles (4 km.) east of Antelope Springs, in ridge
east of Wheeler Amphitheater, House Range [Walcott, 1908f, Pls. XIIL and XV],.Millard County, Utah (C. D.
Walcott, F. B. Weeks, and L. D. Burling. 1905),

Micromitra sculptilis. Eoorthis remnicha?.
Micromitra (Iphidella) pannula ophirensis *Hoorthis thyone.

Obolus mcconnelli pelias. *Syntrophia? unxia.

Obolus rotundatus. Agnostus 3 sp.

Lingulella arguta. Ptychoparia.

Acrothele subsidua. Neolenus inflatus Walcott.
Acrothele subsidua levis. Neolenus intermedius Walcott.
Acrotreta attenuata. _ Neolenus superbus Walcott.
Acrotreta ophirensis. Ogygopsis?.

3y. (For stratigraphic position and association, see p. 156.) Middle Cambrian: About 2,150 feet (655.3 m.) above
the Lower Cambrian and 2,250 (685.8 m.) below the Upper Cambrian, in the shaly limestones forming 1d of
the Marjum limestone [Walcott, 19081, p. 180], 2.5 miles (4 km.) east of Antelope Springs, in ridge east of
Wheeler Amphitheater, House Range [Walcott, 1908, Pls. XIII and XV], Millaid County, Utah (C. D. Wal-
cott, F. B. Weeks, and L. D. Burling, 1905).

Obolus meconnelli pelias. Ptychoparia.
Acrotreta ophirensis. Ogygopsis?.
Agnostus.

4 (same horizon as 3s). (For stratigraphic position and association, see p. 156.) Middle Cambrian: Drift pieces
believed to have come from the Wheeler formation [Walcott, 1908f, p. 181], collected near Antelope Springs,
House Range [Walcott, 19081, Pl. XIII], Millard County, Utah (J. F. Gibbs, 1889).
*Acrothele subsidua. Ptychoparia kingi (Meek).
Agnostus interstrictus White. Asaphiscus wheeleri (Meek).

4e (see 4m and 4n). Middle Cambrian: Limestones about 950 feet (289.6 m.) above the unconformable base of the
Cambrian, in the divide at head of Jackson Creek (locally known as Sheep Creek), a creek flowing into Jack-
son Lake about 0.5 mile (0.8 km.) south of its northwestern corner, Teton Mountains, Grand Teton quadrangle
(U.S. G.8.), Uinta County, Wyo. (C. D. Walcott, 1898).
*Obolus tetonensis. *Acrotreta microscopica tetonensis.
Lingulella (Lingulepis) acuminata meeki. Billingsella coloradoensis.
(Possibly the last named is from a bed different from that containing the other species.)

4g (50 feet below 4h; see 4h, 4k, and 4p). Middle Cambrian: About 325 feet (99.1 m.) above the base of the Cam-
brian, in the Flathead shales of Peale [1893, p. 21], 1 mile (1.6 km.) north of the junction of East Gallatin
and West Gallatin (Gallatin) rivers, 4 miles (6.4 km.) east-northeast of Logan, Threeforks quadrangle
(U.S. G.S.), Gallatin County, Mont. (C. D. Walcott).
Obolus (Westonia) ella.

4h (50 feet above 4g; see 4g, 4k, and 4p). Middle Cambrian: About 375 feet (114.3 m.) above the base of the Cam-
brian, in limestone interbedded in the Flathead shales of Peale [1893, p. 21], 1 mile (1.6 km.) north of the
junction of East Gallatin and West Gallatin (Gallatin) rivers, 4 miles (6.4 km.) east-northeast of Logan,
Threeforks quadrangle (U. 8. G. 8.), Gallatin County, Mont. (C. D. Walcott).
Micromitra pealei. Lingulella (Lingulepis) acuminata meeki.
Obolus tetonensis. Acrotreta pyxidicula.

ay ee

a

i i te

LOCALITIES. 167

4j. Middle Cambrian: Limestone at the head of Deep Creek, Canyon quadrangle (U. S. G. S.), Yellowstone
National Park, Wyo.
Billingsella plicatella.
Hoorthis sp.
*Huenella abnormis.

The first and third of these fossils may not have been collected from the same bed.

4ix (4i is limestone interbedded in these shales; see 4g, 4h, and 4p). Middle Cambrian: About 725 feet (22) m.)
above the base of the Cambrian, in the shales of the Gallatin formation of Peale [1893, Pl. IV], on the north
side of West Gallatin (Gallatin) River, northeast of Logan, Threeforks quadrangle (U. S. G. S.), Gallatin
County, Mont. (C. D. Walcott, 1898).

Obolus (Westonia) ella.

41. (For stratigraphic position and association, see pp. 140 and 158.), Lower Cambrian: Limestone in the equiy-
alent of the Pioche formation at Pioche and in the House Range [Walcott, 1908a, p. 11], on a ridge 2.5
miles (4 km.) northwest of the town of Cherry Creek, White Pine County, Ney. (O. H. Hershey).

Micromitra (Iphidella) pannula.
Acrotreta claytoni.
Acrotreta primeva.

4m (about 175 feet below 4n). Middle Cambrian: Sandstones about 150 feet (45.7 m.) above the unconformable
base of the Cambrian, in the divide at the head of Jackson Creek (locally known as Sheep Creek), a creek
flowing into Jackson Lake about 0.5 mile (0.8 km.) south of its northwestern corner, Teton Mountains,
Grand Teton quadrangle (U.S. G. S.), Uinta County, Wyo. (C. D. Walcott, 1898).
Obolus tetonensis.

4n (about 175 feet above 4m). Middle Cambrian: Limestone about 325 feet (99.1 m.) above the unconformable
base of the Cambrian, in divide at the head of Jackson Creek (locally known as Sheep Creek), a creek flowing
into Jackson Lake about 0.5 mile (0.8 km.) south of its northwestern corner, Teton Mountains, Grand Teton
quadrangle (U.S. G. S.), Uinta County, Wyo. (C. D. Walcott and F. B. Weeks, 1898).
Micromitra pealei. Lingulella helena.
Obolus (Westonia) ella. Acrotreta attenuata.
M. pealer also occurs in locality 4n’, which is probably a slightly different bed at the locality given for 4n.

40 (about 50 feet above 4n). Middle Cambrian: Shale about 375 feet (115 m.) above the unconformable base of
the Cambrian, in divide at the head of Jackson Creek (locally known as Sheep Creek), a creek flowing into
Jackson Lake about 0.5 mile (0.8 km.) south of its northwestern corner, Teton Mountains, Grand Teton
quadrangle (U.S. G. S.), Uinta County, Wyo. (C. D. Walcott, 1898).
Acrotreta definita.

4p (see 4g, 4h, and 4k). Middle Cambrian: About 225 feet (68.6 m.) above the base of the Cambrian, in lime-
stones interbedded in the Flathead shales of Peale [1893, p. 21], on the north side of West Gallatin (Gal-°
latin) River, 2 miles (3.2 km.) northeast of Logan, Threeforks quadrangle (U. S. G. S.), Gallatin County,
Mont. (C. D. Walcott, 1898).
Micromitra pealei.

4q (115 feet above 4v; see 3j and 4v). Middle Cambrian: About 315 feet (96 m.) above the unconformable base
of the Cambrian and 190 feet (57.9 m.) above the top of the quartzitic sandstones, in a shale which corre-
sponds in position to the upper part of shale No. 6 of the Dearborn River section [see Walcott, 1908f, p.
202], on the ridge between Gordon and Youngs creeks, about halfway between Gordon Mountain and Car-
dinal Peak, Ovando quadrangle (U.S. G. S.), Powell County, Mont. (C. D. Walcott, 1905).

*Micromitra (Iphidella) nyssa. Ptychoparia 3 sp.
Micromitra (Iphidella) pannula. Bathyuriscus productus (Hall and Whitfield).
*Acrothele colleni. Zacanthoides.

Wimanella simplex.

4q’ (just below 4q; see 3j, 4q, and 4v). Middle Cambrian: Limestone about 310 feet (94.5 m.) above the uncon-
formable base of the Cambrian and 185 feet (56.4 m.) above the top of the quartzitic sandstones, in a shale
which corresponds in position to the upper part of shale No. 6 of the Dearborn River section [see Walcott,
1908f, p. 202], on the ridge between Gordon and Youngs creeks, about halfway between Gordon Mountain
and Cardinal Peak, Ovando quadrangle (U.S. G. S.), Powell County, Mont. (C. D. Walcott, 1905).
Micromitra (Iphidella) pannula.
Obolus (Westonia) ella.

4r. Upper Cambrian: Just above the Middle Cambrian, in the limestones of the Gallatin formation of Peale
[1893, Pl. IV], on a ridge 8 miles (12.8 km.) east of Yellowstone River and 3 miles (4.8 km.) north-
northeast of Mount Delano, Livingston quadrangle (U.S. G.S.), Park County, Mont. (C. D. Walcott, 1898).

Eoorthis remnicha.

168 CAMBRIAN BRACHIOPODA.

4u. Middle Cambrian: Shales in the Gallatin formation of Peale [1893, Pl. IV], northwest side of canyon, 0.5
mile (0.8 km.) south of Helena, Jefferson County, Mont. (L. 8. Griswold and ©. D. Walcott, 1898).
Obolus (Westonia) ella.
Lingulella helena.

4v (115 feet below 4q; same horizon as 5j; see 3j and 4q). Lower Cambrian: About 200 feet (61 m.) above the
unconformable base of the Cambrian and 75 feet (22.9 m.) above the top of the quartzitic sandstones, in a
shale which corresponds in stratigraphic position to shale No. 6 of the Dearborn River section [see Walcott,
1908, p. 202], Gordon Creek, 6 miles (9.6 km.) from South Fork of Flathead River, Ovando quadrangle
(U.S. G. S.), Powell County, Mont. (C. D. Walcott, 1905).

Micromitra (Iphidella) pannula. Ptychoparia sp.

Obolus (Westonia) ella. Olenopsis? sp.

Acrothele colleni. Albertella helena Walcott.

*Acrothele panderi. Bathyuriscus productus (Hall and Whitfield)?.
*Wimanella simplex k Bathyuriscus? sp.

4w (same horizon as4q). Lower Cambrian: About 315 feet (96 m.) above the unconformable base of the Cambrian

and 190 feet (57.9 m.) above the top of the quartzitic sandstones, in a shale which corresponds in position
to shale No. 6 of the Dearborn River section [see Walcott, 19081, p. 202], on Youngs Creek, about 5 miles
(8 km.) from its junction with Danaher Creek, Ovando quadrangle (U. S. G. 8.), Powell County, Mont.
(C. D. Walcott, 1905).

Wimanella simplex.

Ptychoparia sp.

Zacanthoides sp.

4x (a little higher than 5f; see 4g, 4h, 4k, and 5f). Middle Cambrian: Limestone interbedded in the Wolsey shale
[Weed, 1900, p. 285], at the base of a butte in Belt Park, about 6 miles (9.6 km.) northwest of Neihart, Littles
Belt Mountains quadrangle (U. S. G. S.), Cascade County, Mont. (C. D. Walcott, 1898).
Micromitra pealei.
Obolus tetonensis.
Sceneila.

4y (=54t, which see). (For stratigraphic position and association, see p. 149.) (C. D. Walcott, 1898.)
Obolus (Westonia) ella.
Billingsella coloradoensis.

5. Middle Cambrian: Siliceous shale on Hayward Creek, Braintree, Dedham quadrangle (U.S. G.8.), Norfolk
County, Mass. (W. P. Rust, 1891).
Acrothele gamagei. Agraulos quadrangularis (Whitfield).
Hyolithes shaleri Walcott. Paradoxides harlani Green.

Grabau [1900] cites the following additional species from this locality:
Fucoids or trails?. Hyolithes ? haywardensis Grabau.

Parmophorella acadica (Hartt). Ptychoparia rogersi Walcott.

5a (=54t, which see). (For stratigraphic position and association, see p. 149.) (C. D. Walcott, 1898.)
Obolus wortheni.
Lingulella desiderata.
Billingsella coloradoensis.

5b (=54s, which see). (Hor stratigraphic position and association, see p. 152.) (C. D. Walcott, 1893.)
For the species occurring at this locality, see Locality 54s.

be (=54t, which see). (For stratigraphic position and association, see p. 149.) (C. D. Walcott and L. D. Burling,
1906.)
Obolus wortheni.
*Acrotreta idahoensis.
Billingsella coloradoensis.

5f (a little lower than 4x). Middle Cambrian: Limestone interbedded in the Wolsey shale [Weed, 1900, p. 285],
in Meagher County, on the road to Wolsey, about 4 miles (6.4 km.) south of the divide at the head of Saw-
mill Creek and 11 miles (17.7 km.) south of Neihart, Little Belt Mountains quadrangle (U.S. G.S.), Cascade
County, Mont. (C. D. Walcott, 1898).
Micromitra pealei. Scenella.
Obolus (Westonia) ella. Dorypyge? quadriceps (Hall and Whitfield).
Lingulella desiderata. 4

LOCALITIES. 169

5h (=05d, which see). (For stratigraphic position and association, see p. 150.) (C. D. Walcott, 1898.)
Obolus (Westonia) ella. :

5j (same horizon as 4v; same locality as 3j. but 25 feet below). Lower Cambrian: Above the quartzitic sand-
stones, in a shale which corresponds in position to shale No. 6 of the Dearborn River section [see Walcott,
1908f, p. 202], about 6 miles (9.6 km.) west-northwest of Scapegoat Mountain, on the Continental Divide
between Bar Creek and the headwaters of the south fork of North Fork of Sun River, Coopers Lake quad- *
rangle (U.S. G. S.), Powell County, Mont. (C. D. Walcott, 1905).
Acrothele panderi.
Albertella helena Walcott.

5k. Middle Cambrian: Limestone in Meagher County, on the road to Wolsey, about 1 mile (1.6 km.) south of the
divide at the head of Sawmill Creek and 8 miles (12.8 km.) south of Neihart, Little Belt Mountains quad-
rangle (U.S. G.S.), Cascade County, Mont. (C. D. Walcott, W. H. Weed, and F. B. Weeks, 1895).
Micromitra sp. *Schuchertina cambria.
Dicellomus politus. Billingsella coloradoensis.

51 (50 feet below 5n at same locality; same horizon as 5p and 41). (For stratigraphic position and association, see
p. 141.) Lower Cambrian: Limestone on Smith Point, in Smith Sound, Trinity Bay, Newfoundland (C. D.
Walcott, 1899).
Micromitra (Paterina) labradorica.
Olenellus?.

5n (50 feet above 51 at same locality; 275 feet below 50). (For stratigraphic position and association, see p. 141.)
Lower Cambrian: Shale on Smith Point, in Smith Sound, Trinity Bay, Newfoundland (C. D. Walcott, 1899).
Obolella atlantica.
Callavia bréggeri (Walcott).

5o (about 275 feet above 5n; see 51 and 5n). (For stratigraphic position and association, see p. 141.) Lower
Cambrian: Just below the Middle Cambrian, in shales on Smith Point, in Smith Sound, Trinity Bay, New-
foundland (S. W. Loper and C. D. Walcott, 1899).

Obolella atlantica.
Olenellus?.

5p (same horizon as 5land 41). (For stratigraphic position and association, see p. 141.) Lower Cambrian: Lime-
stone 300 feet (91.4 m.) southeast of the railway station, Manuels, Conception Bay, Newfoundland (C. D.
Walcott, 1899).
Obolella atlantica.
Callavia bréggeri (Walcott).

5r. (For stratigraphic position and association, see p. 141.) Lower Cambrian: Limestone near the railroad track,
1.5 miles (2.4 km.) west of the railway station at Manuels, Conception Bay, Newfoundland (C. D. Walcott,
1899). 3
Micromitra (Paterina) labradorica.
Callavia bréggeri (Walcott).

5t. (For stratigraphic position and association, see p. 141.) Lower Cambrian: Shale and limestone nodules about
20 feet (6 m.) above the base of the Cambrian, on Redrock Point, near Chapple Cove, Hollywood Point, Con-
ception Bay, Newfoundland (J. P. Howley and C. D. Walcott, 1899).
Micromitra (Paterina) labradorica. i .
Obolella atlantica.
Callavia bréggeri (Walcott).

6g. (For stratigraphic position and association, see p. 141.) Middle Cambrian: Limestone near the base of the
Middle Cambrian, the lowest horizon carrying Paradoxides, northwest side of Chapple Arm Harbor, about 1
mile (1.6 km.) from its head, Trinity Bay, Newfoundland (J. P. Howley and ©. D. Walcott, 1899).

Micromitra (Iphidella) ornatella. Acrothele matthewi.
Micromitra (Iphidella) pannula maladensis. Acrotreta misera.
Lingulella ferruginea. Acrotreta sagittalis.

6h. (For stratigraphic position and association, see p. 140.) Middle Cambrian: Limestone in the southwest cove of
Chapple Arm, Trinity Bay, Newfoundland (C. D. Walcott, 1899).
Acrotreta misera.

170 CAMBRIAN BRACHIOPODA.

6i (280 feet below 6s). (For stratigraphic position and association, see p. 140.) Middle Cambrian: Limestone
about 300 feet (91.4 m.) below the base of the Upper Cambrian, on shore north of Fosters Point, Random
Island, Random Sound, Newfoundland (C. D. Walcott, 1899).
Acrotreta sagittalis.
Agnostus.
Microdiscus.

61(=1a, except that the fossils were collected on the east side of the brook). (For stratigraphic position and
association, see p. 140.) (C. D. Walcott, 1899.)
Lingulella ferruginea. Acrotreta?.
Acrothele matthew1. *Eoorthis papias.

6n (=la, except that the fossils were collected on the west side of the brook). (For stratigraphic position and
association, see p. 140.) (C. D. Walcott, 1899.)
Lingulella ferruginea.
Acrothele matthewi.
Acrothele prima costata.

6r. (For stratigraphic position and association, see p. 140.) Middle Cambrian: Limestone on the west side of
Manuels Brook, Conception Bay Newimmadlzad (C. D. Walcott, 1899).
Lingulella ferruginea.
Acrotreta misera.

6s (=6u; 280 feet above 6i). (For stratigraphic position and association, see p. 140.) Upper Cambrian: Just
north of Fosters Point, Random Island, Random Sound, Newfoundland (C. D. Walcott, 1899).
Lingulella ferruginea?.

6u (same horizon as 6s). (For stratigraphic position and association, see p. 140.) Upper Cambrian: Shale on the
west side of Manuels Brook, Conception Bay, Newfoundland (C. D. Walcott, 1899).
Lingulella ferruginea.

6v (375 feet above 6n). (For stratigraphic position and association, see p. 140.) Upper Cambrian: Shaly lime-
stones 325 feet (99.1 m.) above the Middle Cambrian, Manuels Brook, Conception Bay, Newfoundland (C. D.
Walcott, 1899).
Orusia lenticularis.

6w. (For stratigraphic position and association, see p.140.) Middle Cambrian: Limestone at Seal Point Cove, near
Long Point, Trinity Bay, Newfoundland (C. D. Walcott, S. W. Loper, and J. P. Howley, 1899).
Acrotreta sagittalis.

6y. (For stratigraphic position and association, see p. 140.) Upper Cambrian: Sandstone on north side of Random
Island, between Birch and Sandy points, Smith Sound, Trinity Bay, Newfoundland (C. D. Walcott and
S. W. Loper, 1899).

*Lingulella randomensis.

7. (For stratigraphic position and association, see p. 138.) Lower Cambrian: Shaly beds about 1,000 feet (305 m.)
above the quartzitic beds, Silver Canyon, White Mountain Range, Inyo County, Cal. (C. D. Walcott, 1894).
Kutorgina perugata.
Yorkia wanneri?.

7d. (For stratigraphic position and association, see p. 147.) Upper Cambrian: Shales in second cliff, 0.126
mile (0.2 km.) west of Peak post office, 3 miles (4.8 km.) south of Clinton, Briceville quadrangle (U.S. G.S.),
Anderson County, Tenn.
Obolus lamborni.
Lingulella ino.

7i. (For stratigraphic position and association, see p. 139.) Middle Cambrian: Limestone just west of the summit,
on the road east of Schellbourne, Schell Creek Range, White Pine County, Nev. (J. E. Spurr, 1899).
Obolus rotundatus. Lingulella punctata.
Lingulella manticula. Acrotreta idahoensis alta.

7j. Middle Cambrian: Limestones at the north end of the Quinn Canyon Range, 1 mile (1.6 km.) northwest of
the Italian Ranch foothills, Nye County, Nev. (J. E. Spurr, 1899).

Micromitra 2 sp. undt. *Acrotreta cf. idahoensis.
Obolus rotundatus. °Acrotreta primeva?.
Lingulella manticula. °Acrotreta pyxidicula.

°Lingulella similis.

Fossils marked ° may not all be from the same bed or even from the same approximate stratigraphic horizon.

LOCALITIES. 171

7k (see 31 and 333b). (For stratigraphic position and association, see p. 158.) Middle Cambrian: Shales in the
dumps of the Halfmoon and Chisholm mines, southwest slope of Ely Mountains, 3 miles (4.8 km.) north-
west of Pioche, Lincoln County, Ney. (J. E. Spurr, 1899).
‘Obolus (Westonia) ella. ;

7m. Upper? Cambrian: Limestone at Hornet Spring in the Spring Mountain Range, on the road from Indian Spring
to Pahrump Valley, Lincoln County, Nev. (J. E. Spurr, 1899).
*Obolus sp. undt. b.

7r (see 7s and 7v). Middle Cambrian: Calcareous shales 4 miles (6.4 km.) south-southeast of Emigrant Peak,
Silver Peak quadrangle (U.S. G. 8.), Esmeralda County, Nev. (H. W. Turner, 1899).
Obolus meconnelli decipiens.
*Acrothele turneri.

7s (see 7r and 7v). Upper Cambrian: Shales of the Emigrant formation [Turner, 1902, p. 265], 4 miles (6.4 km.)
south-southeast of Emigrant Peak, Silver Peak quadrangle (U. S. G. S.), Esmeralda County, Ney. (H. W.

Turner, 1899).

Obolus mcconnelli pelias.

7v (see 7r and 7s). Upper Cambrian: Shales of the Emigrant formation [Turner, 1902, p. 265], 4.25 miles (6.8 km.)
south-southeast of Emigrant Peak, Silver Peak quadrangle (U. S. G. S.), Esmeralda County, Ney. (H. W.
Turner, 1899).
*Obolus mcconnelli decipiens.
Acrotreta argenta.

-

7w. (For stratigraphic position and association, see p. 156.) Middle Cambrian: Limestone in Rock Canyon in the
Wasatch Mountains, east of Provo, Utah County, Utah (G. H. Girty, 1900).
*Nisusia (Jamesella) utahensis.

Dorypyge?.

7x (=Ty; 50 feet below 8a). Upper Cambrian: Limestone of the Emigrant formation [Turner, 1902, p. 265], about
2.5 miles (4 km.) southeast of Emigrant Pass, Silver Peak quadrangle (U. S. G. S.), Esmeralda County,
Ney. (F. B. Weeks, 1900).
Obolus mcconnelli decipiens.
* Obolus (Fordinia) bellulus.
Lingulella desiderata.

Lingulella (Lingulepis) acuminata.
Acrotreta argenta.
Menocephalus sp.

7y (=7x, which see). (F. B. Weeks, 1900.)
Obolus (Fordinia) bellulus.
Lingulella desiderata.
Lingulella (Lingulepis) acuminata.

Acrotreta argenta.
Menocephalus.

7z. Upper Cambrian: Limestone of the Emigrant formation [Turner, 1902, p. 265], about 3 miles (4.8 km.) south-
east of Emigrant Pass, Silver Peak quadrangle (U.S. G. S.), Esmeralda County, Nev. (F. B. Weeks, 1900).
Obolus (Fordinia) bellulus.
Lingulella desiderata.
Lingulella (Lingulepis) acuminata.

8a (50 feet above 7x). Upper Cambrian: Shaly limestones of the Emigrant formation [Turner, 1902, p. 265],
2 miles (3.2 km.) southeast of Emigrant Pass, Silver Peak quadrangle (U.S. G.S.), Esmeralda County,
Nev. (F. B. Weeks, 1900).
Obolella?.

8b. Lower Cambrian: Limestone in Tollgate Canyon, about 15 miles (24.1 km.) east of White Pine, White Moun-
tain Range, Inyo County, Cal. (C. D. Walcott, 1894).
Kutorgina sp. —
Obolella vermilionensis.
*Wimanella inyoensis.

8b’. Upper Cambrian: Shales of the Emigrant formation [Turner, 1902, p. 265], in a ravine on the east side of
the road about 1 mile (1.6 km.) southwest of Emigrant Pass, Silver Peak quadrangle (U.S. G. 8.), Esmeralda
Ff County, Nev. (Ff. B. Weeks, 1900).
* Acrotreta argenta.

8d (see 372). (For stratigraphic position and association, see p. 131.) Upper Cambrian: Shales at Upper Leitches
Creek, eastern Cape Breton, Nova Scotia (S. W. Loper, 1900).
Lingulella concinna.

172 CAMBRIAN BRACHIOPODA.

8e. (For stratigraphic position and association, see p. 139.) Upper Cambrian: Limestone in Patterson Canyon,
west side of the Schell Creek Range, White Pine County, Nev. (F. B. Weeks, 1900).
Lingulella manticula.

8i. (For stratigraphic position and association, see p. 139.) Upper Cambrian: Limestone at summit of canyon
10 miles (16.1 km.) south of Egan Canyon, east side of Egan Range, White Pine County, Nev. (F. B. Weeks,

1900).
Obolus discoideus. ‘ Lingulella punctata.
Lingulella manticula. EKoorthis?.

8g (=38s and 3t, which see). (For stratigraphic position and association, see p. 156.) (F. B. Weeks, 1900.)
Obolus mcconnelli pelias.
Acrothele subsidua.

8i. (For stratigraphic position and association, see p. 156.) Middle Cambrian: Shales believed to be referable to
the lower portion of the Marjum limestone [Walcott, 1908f, p.-180], found about 0.5 mile (0.8 km.) east of
Antelope Springs, House Range [Walcott, 1908f, Pl. XIII], Millard County, Utah (F. B. Weeks, 1900).
Micromitra sculptilis.
Obolus mcconnelli pelias.
Kutorgina sp.

8j. Middle Cambrian: About 575 feet (175.3 m.) above the unconformable base of the Cambrian, in a shale which
corresponds in position to shale No. 4 of the Dearborn River section [see Walcott, 1908f, p. 202], on the ridge
between Gordon and Youngs creeks, about halfway between Gordon Mountain and Cardinal Peak, Ovando
quadrangle (U. 8. G. S.), Powell County, Mont. (C. D. Walcott, 1905). (
Micromitra (Paterina) superba. Ptychoparia sp.
Obolus meconnelli pelias. Zacanthoides sp.
Bathyuriscus productus? (Hall and Whitfield).

8k. (For stratigraphic position and association, see p. 156.) Middle Cambrian: Shales 0.5 mile (0.8 km.) northwest
of Tyler Springs, east slope of House Range, east of Antelope Springs [Walcott, 1908f, Pl. XIII], Millard
County, Utah (F. B. Weeks, 1900).
Obolus meconnelli pelias.

8m. (For stratigraphic position and association, seep. 139.) Middle Cambrian: Limestone near the south end
of the high ridge 4 miles (6.4 km.) northeast of Osceola, White Pine County, Nev. (F. B. Weeks, 1900).
Obolus meconnelli.
Obolus mcconnelli decipiens.

8n. (For stratigraphic position and association, see p. 139.) Upper Cambrian: Limestone about 500 feet (152 m.)
up in the Cambrian limestones east of Swallow ranch, west side of the Snake Range, 20 miles (32.2 km.)
south of Osceola, White Pine County, Nev. (F. B. Weeks, 1900).
Lingulella desiderata.

80. (For stratigraphic position and association, see p. 139.) Upper Cambrian: Limestone on the slope of the ridge
where the range swings around to the northwest, 2 miles (3.2 km.) north of Aurum, Schell Creek Range,
White Pine County, Nev. (F. B. Weeks, 1900).

* Micromitra sculptilis endJichi. Lingulella punctata.
Micromitra sp. Acrotreta microscopica.
Obolus rotundatus. Eoorthis sp.

8p. (For stratigraphic position and association, see p. 139.) Upper Cambrian: Limestone halfway up the canyon
east of McGill’s ranch, on the west side of the Schell Creek Range, 14 miles (22.5 km.) northeast of Ely,
White Pine County, Nev. (F. B. Weeks, 1900).
Obolus rotundatus?.

8q. Iwer Cambrian: Shales near the contact between the Cambrian and the Triassic, 2 miles (3.2 km.) northwest
of York, York County, Pa. (A. Wanner, 1900).
Obolus sp.
Olenellus thompsoni rudis Walcott.

8r. Upper Cambrian: Shales of the Emigrant formation [Turner, 1902, p. 265], about 8 miles (12.8 km.) south-
east of Emigrant Peak, Silver Peak quadrangle (U.S. G. 8.), Esmeralda County, Nev. (H. W. Turner).
Obolus mcconnelli decipiens.

8v. (For stratigraphic position and association, see p. 146.) Lower Cambrian: Shales in upper portion of Holmia
kjerulfi zone, Ringsaker, near Lake Mjésen, Province of Hedemarken, Norway (Schmalensee, 1900).
Obolella mobergi.
* Acrothele bellapunctata.

LOCALITIES. 1733

8w (see 3101, 320f, and 32ly). (For stratigraphic position and association, see p. 145.) Middle Cambrian: Lime-
stones of Paradoxides forchhammeri zone, at Andrarum, 20 miles (32 km.) northwest of Simrishamn, Province
of Christianstad, Sweden (Schmalensee, 1900).

Micromitra pusilla. Acrotreta sagittalis.

Micromitra (Iphidella) ornatella. *Acrotreta schmalenseei.

*Obolus schmalenseei. Acrotreta socialis.

Lingulella ferruginea. Dolichometopus svecicus Angelin.
Lingulella sp. Elyx laticeps Angelin.

Acrothele coriacea. Solenopleura holometopa Angelin.

8x. (For stratigraphic position and association, see p. 144.) Passage beds between the Upper Cambrian and the
Ordovician: Cératopyge limestone at the cement works at Slemmestad, in Réken, about 3 miles (4.8 km.)
southwest of Christiania, Norway (Schmalensee, 1900).

Obolus (Bréggeria) salteri. Acrotreta socialis.

Lingulella lepis. HKoorthis daunus.

Lingulella sp. Eoorthis wimani.

Acrothele coriacea. Ceratopyge forficula Sars.

*A crotreta seebachi. Triarthrus angelini Linnarsson.

8y. (For stratigraphic position and association, see p. 146.) Lower Cambrian: With Torellella levigata in the
“Sparagmite” sandstone, at Skaérésen, northwest Dalarne, Province of Kopparberg, Sweden (Schmalensee,
1900).
Lingulella nathorsti.
Torellella levigata Linnarsson.

8z. (Hor stratigraphic position and association, see p. 146.) Middle Cambrian: Limestones of Paradoxides
elandicus zone, Borgholm, Oeland Island, Sweden (Schmalensee, 1900).
Acrothele (Redlichella) granulata. Liostracus aculeatus Angelin.
Acrotreta socialis. Ellipsocephalus polytomus Linnarsson.
Aerotreta sp.

9 (same horizon as 9a). (For stratigraphic position and association, see p. 147.) Middle Cambrian: Limestone
on southeastern slope of ridge 1 mile (1.6 km.) north of the northwest corner of Harlan Knob, about 4 miles
(6.4 km.) northeast of Rogersville [see Keith, 1905, areal geology sheet], Hawkins County, Tenn. (C. D.
Walcott, 1891).
Lingulella desiderata.

9a (same horizon as 9). (For stratigraphic position and association, see p. 147.) Middle Cambrian: Limestone
on the south shore of Holston River, at Melinda Ferry, 5 miles (8 km.) southwest of Rogersville [see
Keith, 1896a, areal geology sheet], Hawkins County, Tenn. (C. D. Walcott, 1891).
Lingulella desiderata.
Lingulella similis.

9d. (For stratigraphic position and association, see p. 143.) Upper Cambrian: Obolus sandstone at Jaggowal,
about 20 miles (32.2 km.) east-southeast of Reval, Government of Esthonia, Russia (Schmalensee, 1900).
Obolus apollinis.
Obolus triangularis.
Keyserlingia buchi.

9e. (For stratigraphic position and association, see p. 145.) Upper Cambrian: Sandstone in the Obolus con-
glomerate at Boda, north of Rattvik, Dalarne, Sweden (Schmalensee, 1900).
Obolus apollinis.

9f. (For stratigraphic position and association, see p. 145.) Upper Cambrian: Limestones of the Olenus zone at
Noersnees, west of Christiania, Norway (Schmalensee, 1900).
Lingulella lepis.
Orusia lenticularis.
Peltura scarabeeoides Wahlenberg.

9h (limestone above the Wolsey shale). Middle Cambrian: Limestone on Beaver Creek, 5 miles (8 km.) north
of York, about 8 miles (12.8 km.) north of Canon Ferry, Big Belt Mountains, Fort Logan quadrangle
(U.S. G.S.), Meagher County, Mont. (C. D. Walcott, 1900).
Micromitra pealei. Acrotreta attenuata.
Obolella?. Billingsella plicatella.
9k. Middle Cambrian: Limestone forming le of the Dearborn River section [Walcott, 1908f, p. 201], on North
Fork of Dearborn River, in the eastern part of the Lewis and Clark National Forest, Lewis and Clark
County, Mont. (C. D. Walcott, 1900).
*Dearbornia clarki.

174 CAMBRIAN BRACHIOPODA.

9m. Middle Cambrian: Shale 4 miles (6.4 km.) above Walker’s ranch, on North Fork of Dearborn River, in the
eastern part of the Lewis and Clark National Forest, Lewis and Clark County Mont. (C. D. Walcott,
1900). ;
Obolus (Westonia) ella.

9n (=326e). Lower Cambrian: Dark purplish siliceous shales on Pearl Street, North Weymouth, Norfolk County,
Mass. (H. T. Burr, 1900).
Obolella atlantica.
Callavia burri Walcott.
Callayvia crosbyi Walcott.

90. Middle Cambrian: Siliceous limestone about 15 feet (4.6 m.) above the Coronado quartzite [Lindgren, 1905,
p. 3], 0.5 mile (0.8 km.) southwest of Milk ranch, on the first spur north of the one which the main road
follows, Clifton quadrangle (U.S. G. S.), Graham County, Ariz. (J. M. Boutwell, 1901).
Lingulella lineolata.
Lingulella perattenuata.

9p (about 115 feet above 9r; 55 feet above 12s; almost same horizon as 9x; 10 feet below 9t). (For stratigraphic
position and association, see p. 142.) Upper Cambrian: About 160 feet (48.8 m.) above the porphyry con-
tact in the limestone of the Reagan sandstone, in SE. } NE. } sec. 2, T.4 N., R. 13 W., about 15 miles
(24.2 km.) northwest of Fort Sill, Comanche County, Okla. (E. O. Ulrich, 1901).

Obolus tetonensis ninus. Ptychoparia sp.
*Lingulella ora. Chariocephalus sp.
Linnarssonella girtyi. Illenurus sp.

9q (50 feet below 12d). (For stratigraphic position and association, see p. 142.) Upper Cambrian: About 10 feet
(3 m.) above the porphyry contact and 90 feet (27.4 m.) below the Arbuckle limestone, in limestone of the
Reagan sandstone, in middle of west half of sec. 2, T. 4 N., R. 13 W., about 15 miles (24.2 km.) northwest
of Fort Sill, Comanche County, Okla. (E. O. Ulrich, 1901).

Obolus tetonensis ninus. Eoorthis wichitaensis.
Lingulella ora. Agnostus sp.
Lingulella (Lingulepis) acuminata. Agraulos sp.
Linnarssonella girty1. Ptychoparia sp.
Linnarssonella girtyi?. Pterocephalus sp.

9r (about 125 feet below 9t; about 115 feet below 9p; see 9v). (For stratigraphic position and association, see
p. 142.) Upper Cambrian: About 45 feet (14 m.) above the porphyry contact in the limestone of the
Reagan sandstone, in SE. 4 NE. 4 sec. 2, 7.4 N., R. 13 W., 15 miles (24.2 km.) northwest of Fort Sill,
Comanche County, Okla. (E. O. Ulrich, 1901).
*Obolus tetonensis ninus.
Lingulella similis.
Linnarssonella girtyi.

Acrotreta microscopica.
Agnostus sp.
Ptychoparia sp.

9s (believed to just overlie 9u). (For stratigraphic position and association, see p. 142.) Upper Cambrian: About
85 feet (26 m.) below the Arbuckle limestone, in the limestone of the Reagan sandstone, near middle of
west half of sec. 13, T. 4 N., R. 18 W., 13 miles (20.8 km.) northwest of Fort Sill, Comanche County, Okla.
(EH. O. Ulrich, 1901).
Obolus tetonensis ninus. Lingulella (Lingulepis) acuminata.
Lingulella similis. Eoorthis wichitaensis.

9t (125 feet above 9r; 10 feet above 9p; 25 feet below 9u; see 9v). (For stratigraphic position and association,
see p. 142.) Upper Cambrian: About 170 feet (52 m.) above the porphyry contact in the limestone of the
Reagan sandstone, SE. + NE. 4 sec. 2, T. 4. N., R. 13 W., 15 miles (24.2 km.) northwest of Fort Sill,
Comanche County, Okla. (E. O. Ulrich, 1901).
Obolus matinalis.
Obolus tetonensis ninus.
Lingulella similis.

Acrotreta microscopica.
Hoorthis indianola.
Ptychoparia sp.

9u (believed to just underlie 9s; 25 feet above 9t). (For stratigraphic position and association, see p. 142.) Upper
Cambrian: About 195 feet (59.4 m.) above the porphyry contact in the limestone of the Reagan sandstone,
in SE. + NE. i sec. 2, T. 4.N., R. 13 W., 15 miles (24.2 km.) northwest of Fort Sill, Comanche County,
Okla. (E. O. Ulrich, 1901).

Obolus tetonensis ninus. Syntrophia primordialis.
Lingulella similis. Agnostus sp.
Koorthis indianola. Ptychoparia sp.

Eoorthis wichitaensis.

LOCALITIES. 175

9v (150 feet below 9w; between 9r and 9t). (For stratigraphic position and association, see p. 142.) Upper Cam-
brian: Limestone of the Reagan sandstone about 250 feet (76 m.) below the Arbuckle limestone, SW. 4
sec. 17, 7.4 N., R. 12 W., about 11 miles (17.7 km.) northwest of Fort Sill, Comanche County, Okla. (E. O.
Ulrich, 1901).

Lingulella (Lingulepis) acuminata. Agraulos sp.
Linnarssonella girty1. Chariocephalus? sp.
Agnostus sp. Illeenurus? sp.

9w (150 feet above 9v). (For stratigraphic position and association, see p. 142.) Upper Cambrian: Limestone of
the Reagan sandstone about 100 feet (30.5 m.) below the Arbuckle limestone, SW. } sec. 17, T. 4 N., R. 12
W., 11 miles (17.7 km.) northwest of Fort Sill, Comanche County, Okla. (E. O. Ulrich, 1901).
KHoorthis indianola.
Agnostus.

9x (almost same horizon as 9p). (For stratigraphic position and association, see p. 142.) Upper Cambrian: Sana-
stones lying between beds of quartzite underlying the 300 feet of limestone at the top of the Reagan sand-
stone, SW. fsec. 17, T. 4 N., R. 12 W., about 11 miles (17.7 km.) northwest of Fort Sill, Comanche County,
Okla. (E. O. Ulrich, 1901).
Dicellomus politus.

9z. (For stratigraphic position and association, see p. 142.) Upper Cambrian: Basal beds of the Arbuckle lime-
stone, about 25 feet above the heavy bedded limestone, near the middle of the west half of sec. 13, T. 4 N.,
R. 13 W., about 13 miles (20.8 km.) northwest of Fort Sill, Comanche County, Okla. (H. O. Ulrich, 1901).
Eoorthis wichitaensis.
Dikellocephalus.

10a (see 106). (For stratigraphic position and association, see p. 147.) Middle Cambrian: Sandy layers of the
Rome formation in western railroad cut through Shooks Gap, in Bays Mountains, 10 miles (16.1 km.) south-
east of Knoxville [see Keith, 1895, areal geology sheet], Knox County, Tenn. (C. D. Walcott, 1891).
*Obolus pandemia. ;
*Lingulella auga.
Lingulella similis.

10b. (For stratigraphic position and association, see p. 147.) Middle Cambrian: Sandy layers of the Rome forma-
tion at the western end of the central railroad cut through Shooks Gap, in Bays Mountains, 10 miles (16.1 km.)
_ southeast of Knoxville [see Keith, 1895, areal geology sheet], Knox County, Tenn. (C. D. Walcott, 1891).
Lingulella auga.

10c (50 feet below 10k). (For stratigraphic position and association, see p. 131.) Upper Cambrian: Shales on west
side of Barachois River, eastern Cape Breton, Nova Scotia (S. W. Loper, 1901).
Obolus (Bréggeria) salteri. Schizambon priscus ?.
Lingulella concinna. Acrotreta bisecta.

10d. (For stratigraphic position and association, see p. 131.) Upper Cambrian: Shales on west side of Barachois
River, 0.125 mile (0.2 km.) north of Boisdale road, opposite McMullin’s place, eastern Cape Breton, Nova
Scotia (S. W. Loper, 1901).
Obolus (Bréggeria) salteri.
Lingulella concinna.

Schizambon priscus.
Acrotreta bisecta.

10e (50 feet above 10f). (For stratigraphic position and association, see p. 131.) Upper Cambrian: Shales on the
east branch of Barachois River, 0.5 mile (0.8 km.) north of the crossroad from Boisdale to Upper Leitches
Creek, eastern Cape Breton, Nova Scotia (S. W. Loper, 1901).
Obolus (Bréggeria) salteri. Acrotreta bisecta.
Lingulella concinna. Acrotreta convexa.
Schizambon priscus.

10f (=10g; 50 feet below 10e). (For stratigraphic position and association, see p. 131.) Upper Cambrian: Shales
on the east branch of Barachois River, 0.75 mile (1.2 km.) north of the crossroad from Boisdale to Upper
Leitches Creek, eastern Cape Breton, Nova Scotia (S. W. Loper, 1901).
Obolus (Bréggeria) salteri. Acrothele sp.
Lingulella concinna. Acrotreta bisecta.
Schizambon priscus.

10g (=10f). (For stratigraphic position and association, see p. 131.) (S. W. Loper, 1901.)
Obolus (Bréggeria) salteri. Acrotreta bisecta.
Lingulella concinna. Acrothyra proavia.
Schizambon priscus.

176 CAMBRIAN BRACHIOPODA.

10h. (For stratigraphic position and association, seep. 131.) Upper Cambrian: Shale on small east branch of Bara-

chois River, 0.75 mile (1.2 km.) north of the crossroad from Boisdale to Upper Leitches Creek, eastern Cape

Breton, Nova Scotia (S. W. Loper, 1901).
Lingulella concinna.
Schizambon priscus.

Acrotreta bisecta.
Orusia lenticularis.

10i. (For stratigraphic position and association, see p. 131.) Upper Cambrian: Shale in high bank on west side
of Barachois River, just north of the Boisdale road, eastern Cape Breton, Nova Scotia (S. W. Loper, 1901).
Obolus (Bréggeria) salteri. Schizambon priscus.
Lingulella concinna. Acrotreta convexa.

10k (50 feet above 10c). (For stratigraphic position and association, see p. 131.) Upper Cambrian: Shale on west
bank of Barachois River, about 0.25 mile (0.4 km.) north of the Boisdale road, eastern Cape Breton, Nova
Scotia (S. W. Loper, 1901).
Schizambon priscus. :

101. (For stratigraphic position and association, see p. 131.) Upper Cambrian: Shale on east bank of Barachois
River, 6 miles (9.6 km.) from Little Bras d’Or Lake, eastern Cape Breton, Nova Scotia (S. W. Loper, 1901).
Obolus (Bréggeria) salteri. Acrotreta bisecta.
Lingulella concinna. Acrotreta convexa.
Schizambon priscus.

10m (see 372a). (For stratigraphic position and association, see p. 131.) Upper Cambrian: Shales 2 miles (3.2 km.)
south of the Boisdale road from Upper Leitches Creek, toward the head of Barachois River, eastern Cape
Breton, Nova Scotia (S. W. Loper, 1901).
Obolus (Bréggeria) salteri.
Lingulella concinna.

10n. (For stratigraphic position and association, see p. 131.) Upper Cambrian: Shale in ravine on east side of
Barachois Glen, 3 miles (4.8 km.) from Barachois, eastern Cape Breton, Nova Scotia (S. W. Loper, 1901).
Obolus (Bréggeria) salteri.
Lingulella concinna.
Acrotreta bisecta.

100. (Forstratigraphic position and association, see p.132.) Middle? Cambrian: Arenaceous shales in the railroad
cut on the shore of Bras d’Or Lake, at Barachois, eastern Cape Breton, Nova Scotia (S. W. Loper, 1901).

Obolus (Westonia) escasoni?.

10p (a little below 10q; see 3440). (For stratigraphic position and association, see p. 134.) Middle Cambrian:

Sandstone just below the waterfall in Division E2b of Matthew’s [1903, p. 21] Etcheminian, Dugald Brook,
Indian River, eastern Cape Breton, Nova Scotia (S. W. Loper, 1901).

Obolus (Paleeobolus) bretonensis. Acrothele avia.

Lingulella atava. Acrotreta gemmula.

Lingulella collicia. Acrothyra proavia.

Lingulella triparilis. Acrothyra sera.

Lingulella sp. Acrothyra signata.

Lingulella (Lingulepis) greswa. Acrothyra signata orta.

Lingulella (Lingulepis) greewa robusta. *Protorthis (Loperia) dugaldensis.

Lingulella (Lingulepis) longinervis.

Matthew [1903, p. 25] gives the following as occurring in Division 2b:
Acrothyra signata tarda=Acrothyra sera. Orthotheca.
Lingulepis longinervis. Bradorona perspicator magna Matthew.

Bassler cites the following from this locality:

Bradoria acuta (Matthew).
Bradoria benepuncta (Matthew).
Bradoria ovalis (Matthew).

Bradoria perspicator (Matthew) ss.
Bradoria robusta (Matthew).
Bradoria spectator (Matthew).

10p’. (For stratigraphic position and association, see p. 134.) Middle Cambrian: Sandstone 0.25 mile (0.4 km.)
from lower bridge, on Gregwa Brook, Indian River, eastern Cape Breton, Nova Scotia (S. W. Loper, 1901).

Lingulella (Lingulepis) gregwa.
Lingulella (Lingulepis) gregwa robusta.

Lingulella (Lingulepis) longinervis.
Acrothyra sera.

LOCALITIES. : 177

10p’”. (For stratigraphic position and association, see p. 134.) Middle Cambrian: Sandstone on the small brook
on the hill between the bridge over Indian River and McPhees Brook, Cape Breton, Nova Scotia (S. W.
Loper, 1901).

Obolus (Paleeobolus) bretonensis. Acrotreta gemmula.
Lingulella (Lingulepis) gregwa. Acrothyra sera.

Lingulella (Lingulepis) gregwa robusta. Bradoria robusta (Matthew).
Lingulella (Lingulepis) longinervis. Bradoria obesa (Matthew).

Acrothele avia.

10q (a little above 10p; see 3440). (For stratigraphic position and association, see p. 134.) Middle Cambrian:
Sandstone below the waterfall in Division E2b of Matthew’s [1903, p. 21] Etcheminian, Dugald Brook,
Indian River, eastern Cape Breton, Nova Scotia (S. W. Loper, 1901).
Acrothyra proavia.

Matthew [1903, p. 25] cites the following species from Division 2b:
Acrothyra signata tarda=Acrothyra sera. Orthotheca.
Lingulepis longinervis. Bradorona perspicator magna Matthew.

Bassler cites the following from this locality:
Bradoria elongata n. sp.

10r. (For stratigraphic position and association, see p. 131.) Upper Cambrian: Arenaceous shales of Division
C3a? of Matthew at McAdam shore, East Bay, east of Bras d’Or Lake, eastern Cape Breton, Nova Scotia
(S. W. Loper, 1901).
Obolus (Bréggeria) salteri. Obolus (Westonia) escasoni?.
Obolus (Palzeobolus) bretonensis. *Lingulella lens.

10s. (For stratigraphic position and association, see p. 132.) Middle Cambrian: Sandstone on McLean Brook,
near Marion Bridge, eastern Cape Breton, Nova Scotia (S. W. Loper, 1901).
Lingulella cania.
Lingulella (Lingulepis) exigua.
Beyrichona triceps Matthew.

10t. (For stratigraphic position and association, see p. 132.) Middle Cambrian: Sandstone on McLean Brook,
near Marion Bridge, eastern Cape Breton, Nova Scotia (S. W. Loper, 1901).
Lingulella (Lingulepis) exigua.

10v. Upper Cambrian: Shales in the “St. Croix sandstone’ at Fox Glen, about 8 miles (12.8 km.) east of Baraboo,
Baraboo quadrangle (U. 8S. G. 8.), Sauk County, Wis.
*Obolus pheres. ;
Lingulella winona.
*Acrotreta nox.

10w. (For stratigraphic position and association, see p. 139.) Middle Cambrian: Shaly limestones about 5 miles
(8 km.) northeast of Osceola, on the east side of the Snake Range, White Pine County, Nev. (C. D. Walcott,
1903).
Micromitra sculptilis.
Obolus mcconnelli.

10y (same horizon as 10z). (For stratigraphic position and association, see p. 155.) Middle Cambrian: About
2,900 feet (884 m.) above the Lower Cambrian and 1,500 feet (457.2 m.) below the Upper Cambrian, in the
central part of the limestone forming la of the Marjum limestone [Walcott, 1908f, p. 179], about 1 mile
(1.6 km.) south-southwest of Marjum Pass, House Range [Walcott, 1908f, Pl. XIII], Millard County, Utah
(C. D. Walcott and F. B. Weeks, 1903).

Micromitra sculptilis. Acrotreta attenuata.
Obolus mcconnelli. Agnostus.
Lingulella arguta. Ptychoparia.
Acrothele subsidua. Anomocare.

10z (same horizon as 10y). (Forstratigraphic position and association, seep. 155.) Middle Cambrian: About 2,900
feet (884 m.) above the Lower Cambrian and 1,500 feet (457.2 m.) below the Upper Cambrian, in the central
part of the limestone forming la of the Marjum limestone [Walcott, 1908f, p. 179], in the long cliff about
2 miles (3.2 km.) southeast of Marjum Pass [see Walcott, 1908f, Pls. XIII and XV], House Range, Millard
County, Utah (C. D. Walcott, F. B. Weeks, and L. D. Burling, 1903 and 1905).

*Dicellomus prolificus. Ptychoparia 2 sp.
*Acrotreta bellatula. Agraulos.
Agnostus 2 sp. Anomocare.

62667°—von 51, pr 1—12 12

178

11.

CAMBRIAN BRACHIOPODA.

(For stratigraphic position and association, see p. 147.) Middle Cambrian: Sandstones and shales of the

Rome formation, about 1 mile (1.6 km.) east of Post Oak Springs [see Hayes, 1894, areal geology sheet],

Roane County, Tenn. (C. D. Walcott, 1891).
Lingulella ino.
*Lineulella tarpa.

lla.

(For stratigraphic position and association, see p. 147.) Middle Cambrian: Sandstone between First and

Armstrong creeks, in the southeast corner of the Maynardville quadrangle (U. S. G. S.), Union County,

Tenn. (C. D. Walcott, 1891).
Obolus sinoe.
Lingulella tarpa.
Dicellomus appalachia.

11c.

*Lingulella welleri.

Upper Cambrian: Hardyston quartzite [Weller, 1900, pp. 110 and 112], O’Donnell and McManniman’s quarry,
Newton, Sussex County, N. J. (H. E. Dickhaut,

1901).

Weller [1900, p. 12] cites the following from this locality:

Foraminifera?.

Lingulella stoneana=Obolus (Westonia) stoneanus.
*Orthis newtonensis=Eoorthis newtonensis.
Microdiscus ? sp.

Olenellus ? sp.

1ld.

(For stratigraphic position and association, see p. 137).

Ptychoparia newtonensis Weller.
Ptychoparia 2 sp. undt.

Anomocare parvula Weller.
Dikellocephalus newtonensis Weller.

Upper Cambrian: Arenaceous limestone about 2

miles (3.2 km.) north of Montana, in sec. 22, T. 35 N., R. 1 E., Iron County, Mo. (D. K. Greger).

Obolus matinalis ?.
Billingsella coloradoensis,
Eoorthis remnicha texana?.

Ile.

(For stratigraphic position and association, see p.

137.) Middle Cambrian: In thin-bedded limestones south-

southwest of Potosi, Washington County, Mo. (D. K. Greger).

Obolus matinalis ?.
Lingulella similis.
Lingulella sp.

11).
stone, Mine Lamotte, Madison County, Mo. (EH.
*Obolus lamborni.
Obolus sinoe.

11k. (For stratigraphic position and association, see p.

Linnarssonella girtyi.
Acrotreta microscopica missouriensis.
Billingsella coloradoensis.

(For stratigraphic position and association, see p. 1387.) Middle Cambrian: Basal part of Bonneterre lime-

O. Ulrich, 1904).
Lingulella acutangula.
Dicellomus nanus.

137.) Middle Cambrian: In sandstones and limestones of

the ‘‘ Edgewise beds,’ St. Francois County, Mo. (F. Nason, 1901).

Lingulella acutangula.
Linnarssonella girtyi.
*Acrotreta microscopica missouriensis.

111. (for stratigraphic position and association, see

p. 187.) Upper Cambrian: Arenaceous limestone of the

Elvins formation, 50 feet (15.2 m.) above the “‘ Edgewise beds,” St. Francois County, Mo. (F. Nason, 1901).

Lingulella acutangula ?.-
Billingsella coloradoensis.
Eoorthis remnicha texana ?.

llm. (For stratigraphic position and association, see p. 137.) Middle Cambrian: Drill cores of limestone in the
Bonneterre limestone, at horizons 10 and 20 feet (3 and 6 m.) above the Lamotte sandstone, at Flat River,

St. Francois County, Mo. (F. Nason, 1901).
Micromitra sp.
Micromitra (Paterina) cf. stissingensis.
Obolus lamborni. |

11n.

(for stratigraphic position and association, see p.

Lingulella cf. ora. mi
Dicellomus nanus.
Dicellomus politus.

155.) Middle Cambrian: About 3,000 feet (914.4 m.) above

the Lower Cambrian and 1,400 feet (426.7 m.) below the Upper Cambrian, in the upper part of the lime-
stone forming 1a of the Marjum limestone [Walcott, 1908f, p. 179], in the long cliff 2 miles (3.2 km.) south-
east of Marjum Pass [see Walcott, 1908f, Pls. XIII and XV], House Range, Millard County, Utah (C. D.
Walcott, F. B. Weeks, and L. D. Burling, 1903 and 1905).

Obolus mcconnelli pelias.
*Obolus (Fordinia) gilberti.
Acrotreta bellatula.

*Acrotreta marjumensis.
*Acrotreta cf. sagittalis.
Agnostus 4 sp.

LOCALITIES. AS)

llo. (For stratigraphic position and association, see p. 155.) Middle Cambrian: About 2,750 feet (838.2 m.)
above the Lower Cambrian and 1,650 feet (502.9 m.) below the Upper Cambrian, in limestone at the base,
la, of the Marjum limestone [Walcott, 1908f, p. 179], about 4 miles (6.4 km.) southeast of Antelope
Springs, in the spur at the junction of the Deseret and Swasey Spring roads [Walcott, 1908f, Pl. XIII],
House Range, Millard County, Utah (C. D. Walcott, F. B. Weeks, and L. D. Burling, 1903 and 1905).

Micromitra (Iphidella) pannula ophirensis. | Stenotheca sp.
Obolus mcconnelli pelias. Hyolithes.
Obolus rotundatus. Bathyuriscus ?.
Acrotreta idahoensis. Ptychoparia 2 sp.
Annelid trails. Anomocare.

1lp. (For stratigraphic position and association, see p. 156.) Middle Cambrian: About 2,000 feet (609.6 m.) above

_ the Lower Cambrian and 2,400 feet (731.5 m.) below the Upper Cambrian, in the limestones forming le

of the Marjum limestone [Walcott, 1908f, p. 181], in the long cliff about 2.5 miles (4 km.) southeast of Mar-

jum Pass [ Walcott, 1908f, Pls. XIII and XV], House Range, Millard County, Utah (C. D. Walcott, F. B.

Weeks, and L. D. Burling, 1905).
Linnarssonella sp. Ogygopsis ?.

Sponge spiculee. Ptychoparia 2 sp.

Agnostus, several sp:

11g (=11y and 30g; same horizon as 3w). (For stratigraphic position and association, see p. 156.) (C. D. Walcott,
F. B. Weeks, and L. D. Burling, 1903 and 1905.)

*Obolus meconnelli pelias. Neolenus inflatus Walcott.

Lingulella arguta. Neolenus intermedius Walcott.

Acrothele subsidua. Neolenus intermedius pugio Walcott. =
Nisusia (Jamesella) nautes?. Neolenus superbus Walcott.

Nisusia (Jamesella) spencei. Ogygopsis ?.

Eoorthis thyone.

lls. (For stratigraphic position and association, see p. 157.) Middle Cambrian: Shales just above Simpson Spring,
about 20 miles (32.2 km.) west-southwest of Vernon, on the stage road from Vernon to Fish Spring, Tooele
County, Utah (C. D. Walcott, 1903).
Obolus (Westonia) ella ?.
Micromitra sculptilis.

11u. (For stratigraphic position and association, see p. 156.) Middle Cambrian: Lower portion of the shales
forming the Wheeler formation, in Rainbow Valley, House Range [see Walcott, 1908f, Pl. XIII], Millard
County, Utah (C. D. Walcott, 1903).
Acrothele subsidua.

llw (=30c). (For stratigraphic position and association, see p. 157.) Middle Cambrian: About 1,050 feet (320 m.)
above the Lower Cambrian and 3,350 feet (1,021.1 m.) below the Upper Cambrian, in the shales forming
1d of the Swasey formation [Walcott, 1908f, p. 182], at the head of Dome Canyon, House Range [Walcott,
1908f, Pl. XIII], Millard County, Utah (C. D. Walcott and F. B. Weeks, 1903).

Lingulella arguta.
Ptychoparia.

11x (=8x). (For stratigraphic position and association, see p. 156.) (C. D. Walcott, 1903.)
Obolus rotundatus.
Lingulella arguta.

lly (=11q and 30g). (For stratigraphic position and association, see p. 156.) (C. D. Walcott, 1903.)
Lingulella arguta.
Acrothele subsidua.
Acrotreta cf. ophirensis.

11z. (For stratigraphic position and association, see p. 132.) Middle Cambrian: Sandstone on Big Ridge 2
miles (3.2 km.) south of Marion Bridge, on the canal of John McDougald, eastern Cape Breton, Nova Scotia
(S. W. Loper).
Obolus (Westonia) escasoni.
Lingulella (Lingulepis) exigua.

12. (For stratigraphic position and association, see p. 147.) Middle Cambrian: Sandy shale on Webbs Ridge, in
gap west of Simpson’s farm, 6 miles (9.6 km.) northeast of Knoxville, Knox County, Tenn. (C. D. Walcott,
1891).
Linnarssonella tennesseensis.

180

12j (50 feet below 12g; 40 feet above 121).

CAMBRIAN BRACHIOPODA.

(For stratigraphic position and association, see p. 142.) Upper Cam-

brian: Lower part of Arbuckle limestone, second fossiliferous horizon in the section at Small Hill, 2 miles
(3.2 km.) southwest of Sienal Mountain, about 8 miles (12.8 km.) west of Fort Sill, Comanche County, Okla.

(E. O. Ulrich, 1901).
Eoorthis wichitaensis.
Agraulos sp.
Dikellocephalus sp.

Ptychaspis sp.
Illeenurus sp.

12k (15 feet below 12n in Springer section). (For stratigraphic position and association, see p. 142.) Upper Cam-
brian: Limestone of the Reagan sandstone, about 225 feet (69 m.) above the porphyry contact and 55 feet
(17 m.) below the Arbuckle limestone, on the west side of Honey Creek, near southeast corner sec. 35, T.1S.,
R.1E., 7 miles (11.2 km.) north of Springer, Ardmore quadrangle (U.S. G. S.), Carter County, Okla. (E. O.

Ulrich, 1901).
Obolus tetonensis ninus.
Lingulella similis.
Acrotreta microscopica.
*HKoorthis indianola.

Koorthis remnicha.

Eoorthis wichitaensis.

Eoorthis wichitaensis lzviusculus.
Chariocephalus sp.

12m. (For stratigraphic position and association, see p. 142.) Upper Cambrian: Arbuckle limestone [in the
section 7 miles (11.2 km.) north of Springer this horizon is about 30 feet (9.1 m.) above the Reagan sandstone],
NE. fsec. 2,T.28., R.1E., Ardmore quadrangle (U.S. G.S.), Carter County, Okla. (E. O. Ulrich, 1901).

Obolus tetonensis ninus.
Lingulella similis.
Eoorthis remnicha texana.

Agraulos sp.
Ptychaspis sp.

12n (15 feet above 12k in Springer section). (For stratigraphic position and association, see p. 142.) Upper Cam-
brian: Limestone of the Reagan sandstone about 240 feet (73 m.) above the porphyry contact and 40 feet
(12 m.) below the Arbuckle limestone, NW. 14sec. 1, T.2 S., R.1 E., 7 miles (11.2 km.) north of Springer,
Ardmore quadrangle (U.S. G. S.), Carter County, Okla. (E. O. Ulrich, 1901).

Obolus tetonensis ninus.
Lingulella similis.

Lingulella (Lingulepis) acuminata.
Acrotreta microscopica.

Eoorthis indianola.

Hoorthis remnicha.

Eoorthis remnicha texana.
Eoorthis wichitaensis.

Eoorthis wichitaensis leviuseulus.
Syntrophia primordialis.
Ptychoparia sp.

Chariocephalus sp.

12p. (For stratigraphic position and association, see p. 142.) Upper Cambrian: About 225 feet (69 m.) above the
igneous rocks in the limestone of the Reagan sandstone, at the northwest extremity of the Arbuckle
Mountains, about 4 miles (6.4 km.) east of Homer, Carter County, Okla.

Obolus tetonensis ninus.
Lingulella similis.

Lingulella (Lingulepis) acuminata.
Acrotreta curvata.

Acrotreta microscopica.

*A crotreta ulrichi.

Linnarssonella girtyi.

EKoorthis indianola.

Eoorthis remnicha.

*Koorthis wichitaensis.

*Koorthis wichitaensis leviusculus.
Agraulos sp.

Ptychoparia sp.

Chariocephalus sp.

Ileenurus sp.

12q. (or stratigraphic position and association, see p. 147.) Upper Cambrian: Knox dolomite on Bunker Hill,
6 miles (9.6 km.) northeast of Rogersville [see Keith, 1905, areal geology sheet], Hawkins County, Tenn.

(M. R. Campbell, 1892).
*Syntrophia campbelli.

12v. Lower Cambrian: Sandstone above the quartzite 1 mile (1.6 km.) west of Fruitville, on Little Conestoga
Creek, Manheim Township, Lancaster County, Pa. (C. D. Walcott, 1909).

Obolella crassa?

13. (For stratigraphic position and association, see p. 147.) Middle Cambrian: Sandstones of the Rome formation
1.5 miles (2.4 km.) east of Post Oak Springs [see Hayes, 1894, areal geology sheet], Roane County, Tenn.

(C. D. Walcott, 1891).
Lingulella ino.
*]innarssonella tennesseensis.

13b. (For stratigraphic position and association, see p. 147.) Middle Cambrian: Sandstones of the Rome formation
northeast of Rhea Springs [see Hayes, 1894, areal geology sheet], Roane County, Tenn. (C. D. Walcott, 1891).

Micromitra (Paterina) crenistria.
*Lingulella ino.

LOCALITIES. 181

18c. (For stratigraphic position and association, see p. 147.) Middle Cambrian: Sandstones of the Rome formation,
west side of the sandstone ridge about 2.5 miles (4 km.) southwest of Rome [see Hayes, 1902, historical
geology sheet], Floyd County, Ga. (C. D. Walcott, 1891).
Lingulella ino.

13d (=13d’). (For stratigraphic position and association, see p. 134.) Middle Cambrian: Sandstones opposite the
third waterfall in Dugald Brook, between Divisions E2a and E2b of Matthew’s [1903, p. 21] Etcheminian,
Dugald Brook, Indian River, eastern Cape Breton, Nova Scotia (S. W. Loper, 1903)
Lingulella (Lingulepis) longinervis.
Acrothele avia.
Bradoria robusta (Matthew).

13d’ (=13d). (For stratigraphic position and association, see p. 134.) (S. W. Loper, 1903.)
Obolus (Palezeobolus) bretonensis. Acrothele avia.
Lingulella atava.
Lingulella collicia.

Acrothyra sera.
| Acrothyra signata.

13d” (see 13p, 13g, 13f, and 13p’). (For stratigraphic position and association, see p. 1384.) Middle Cambrian:
nee i feet (3 m.) below Division E2a of Matthew’s [1903, p. 21] ipiielncunain in, Dugald Brook,
Indian River, eastern Cape Breton, Nova Scotia (S. W. Loper, 1903).
Lingulella (Lingulepis) longinervis. Acrothele prima.
Acrothele avia. ‘| Acrothyra signata orta.

Bassler cites the following from this locality:
Bradoria benepuncta (Matthew). Bradoria robusta (Matthew).
Bradoria perspicator (Matthew) (ss). Bradoria rugulosa Matthew (emend.).

18e (see 3441). (For stratigraphic position and association, see p. 134.) Middle Cambrian: Sandstones o* Divi-
sion E2e of Matthew’s [1903, p. 21] Etcheminian, Dugald Brook, Indian River, eastern Cape Breton, Nova
Scotia (S. W. Loper, 1903).
Obolus (Palzeobolus) bretonensis lens.
Acrothyra proavia.
Acrothyra sera.

Matthew [1903, p. 25] gives the following fauna occurring in Ze:
Acrothyra signata orta.
Bradorona observator levis Matthew.

13f (see 13p, 18g, 13d’, and 13p’). (For stratigraphic position and association, see p. 134.) Middle Cambrian:
Sandstones 20 feet (6 m.) above Division E2a of Matthew’s [1903, p. 21] Etcheminian, Dugald Brook,
Indian River, eastern Cape Breton, Nova Scotia (S. W. Loper, 1903).
Lingulella (Lingulepis) longinervis.
Acrothyra sera.

13g (see 13p, 13f, 13d’, and 13p’). (For stratigraphic position and association, see p. 134.) Middle Cambrian:
Sandstones 10 feet (3 m.) above Division E2a of Matthew’s [1903, p. 21] Etcheminian, Dugald Brook, Indian
River, eastern Cape Breton, Nova Scotia (S. W. Loper, 1903).
Lingulella (Lingulepis) longinervis.
Bassler cites the following species from this locality:
Hymenocaris? matthewi n. sp.
13h. (For stratigraphic position and association, see p. 131.) Upper Cambrian: Shale on east bank of Barachois
River, 1.5 miles (2.4 km.) north of Boisdale, eastern Cape Breton, Nova Scotia (S. W. Loper, 1903).
Obolus (Bréggeria) salteri. Schizambon priscus.
Lingulella concinna. | Acrotreta bisecta.
13i (little different horizon than 18r). (For stratigraphic position and association, see Dp. 132.) Middle Cambrian:
Sandstone of the ‘‘Johannian”’ Division of Matthew’s section, on Gillis Brook, East Bay, east of Bras d’Or
Lake, eastern Cape Breton, Nova Scotia (S. W. Loper, 1908).
Lingulella tumida.
13k (see 344f). (For stratigraphic position and association, see p. 135.) Middle Cambrian: Shales of Matthew’s
[1903, p. 15] Coldbrook, above the great falls in Dugald Brook, Indian River, eastern Cape Breton, Nova
Scotia (S. W. Loper, 1903).
Micromitra (Iphidella) pannula?.
*Obolus? torrentis.
Lingulella (Lingulepis?) pumila?.
131(=131’). (For stratigraphic position and association, see p. 133.) (S. W. Loper, 1903.)
Obolus (Palzobolus) bretonensis lens. Acrothele avia.
Lingulella (Lingulepis) longinervis. Acrothyra proavia.

Acrothyra sera.
*Acrothyra signata prima.

182

CAMBRIAN BRACHIOPODA.

13 (=131; see 3441). (For stratigraphic position and association, see p. 133.) Middle Cambrian: In the shaly
sandstones of Division E3a of Matthew’s [1903, p. 21] Etcheminian, Dugald Brook, Indian River, eastern

Cape Breton, Nova Scotia (S. W. Loper, 1903).
Obolus (Palzeobolus) bretonensis.
Lingulella atava.

Matthew [1903] cites the following from this locality:
Obolus lens (pp. 58, 80).
Obolus (Palzeobolus) bretonensis (p. 26).
Lingula sp.

Leptobolus sp.

Bassler cites the following from this locality:
Bradoria acuta (Matthew).
Bradoria curta Bassler.

13m.

Acrothele avia.
Acrothele proles.

Acrothele abayia.
Acrothyra proavia (p. 57).
*Acrothyra proayvia prima.

(For stratigraphic position and association, see p. 133.) Middle Cambrian: Sandstones of Division H3f of

Matthew’s [1903, p. 76] Etcheminian, on Gillis Brook, Indian River, eastern Cape Breton, Nova Scotia

(S. W. Loper, 1903).
Obolus (Palzeobolus) bretonensis lens.
Lingulella collicia.

Matthew [1903] cites the following: -
Leptobolus collicia=Lingulella collicia.
Leptobolus collicia collis=Lingulella collicia.
Acrothele avia puteis.

Acrothele proles.

Bassler cites the following from locality No. 13m’:
Bradoria acuta (Matthew).
Bradoria vigilans Matthew.
Beyrichona rutellum (Matthew).

18n (see 344d).

(For stratigraphic position and association, see p. 133.)

Acrothele avia.
*Acrothele proles.

Acrothyra proavia crassa=Acrothyra proayia.
Acrothyra proavia prima=Acrothyra proayia.
Leperditia?? rugosa.

Bradoria scrutator.

Middle Cambrian: Sandstones of Divi-

sion E3f of Matthew’s [1903, p. 21] Etcheminian, on Dugald Brook, Indian River, eastern Cape Breton,

Nova Scotia (S. W. Loper, 1903).
Lingulella atava.
Acrothele avia.
Acrothele proles.

Matthew [1903, p. 37] cites the following:
~“Leptobolus atavus=Lingulella atava.
Leptobolus collicia=Lingulella collicia.
Leptobolus collicia collis=Lingulella collicia.
Acrothele proles.
Acrothyra crassa?=Acrothyra proavia.

Bassler cites the following:
Bradoria scrutator (Matthew).
Indiana lippa (Matthew).
Walcottella fusiformis (Matthew).

18n/.

Acrothyra proavia prima?=Acrothyra proavia.
Bradorona perspicator major.

Bradorona scrutator.

Solenopleura (?) bretonensis (part).

(For stratigraphic position and association, see p. 133.) Middle Cambrian: Sandstones of Division E3e of

Matthew’s [1903, p. 21] Etcheminian, Dugald Brook, Indian River, eastern Cape Breton, Nova Scotia

(S. W. Loper, 1903).
*Obolus (Palzobolus) bretonensis lens.
*Lingulella atava.
*Lingulella collicia.

Matthew [1903, p. 27] cites the following:
Obolus lens.
Obolus lens longus.
Lingulella tumida.
Lingulella sp.
. Leptobolus atavus.
Jeptobolus collicia.
Acrothele abayia.
Acrothele avia.
Acrothyra prozvia.

*Lineulella tumida.
*Acrothele ayia.
Acrothyra proayia.

Acrothyra proavia crassa.
Indiana ovalis.

Bradorona observator ligata.
Bradorona scrutator.
Bradoria rugulosa.

Bradoria vigilans.
Schmidtella? acuta.
Schmidtella? pervetus.

LOCALITIES. 183

Bassler cites the following:

Indiana lippa (Matthew). Bradoria vigilans Matthew
Bradoria robusta (Matthew). Bradoria ovalis Matthew.
Bradoria rugulosa Matthew. Bradoria acuta (Matthew).

Bradoria scrutator (Matthew).

13n” (see 344b). (For stratigraphic position and association, see p. 183.) Middle. Cambrian: Sandstones of
Division E3d of Matthew’s [1903, p. 21] Etcheminian, Dugald Brook, Indian River, Cape Breton, Nova
Scotia (S. W. Loper, 1903).
Obolus (Palzeobolus) bretonensis.
Lingulella atava.
Acrothyra proavia.

Matthew [1903, p. 26] cites the following:
Obolus bretonensis. Acrothele avia.
Leptobolus atavus. Bradorona spectator zequat.

Bassler cites the following:
Bradoria acuta (Matthew).
Bradoria elongata n. sp.
Bradoria obesa (Matthew).

Bradoria robusta (Matthew).
Bradoria vigilans Matthew.

13p (see 13g, 13f, 13d’, and 13p’). (For stratigraphic position and association, see p. 134.) Middle Cambrian:
Sandstones 40 feet (12.2 m.) above Division H2a of Matthew’s [1903, p. 21] Etcheminian, Dugald Brook,
Indian River, eastern Cape Breton, Nova Scotia (S. W. Loper, 1903).
Lingulella (Lingulepis) longinervis.
Acrothyra sera?.

13p’ (see 13p, 13g, 13f, and 13d’’.) (For stratigraphic position and association, see p. 134.) Middle Cambrian:
Sandstone 45 feet (13.6 m.) above Division E2a of Matthew’s [1903, p. 21] Etcheminian, Dugald Brook,
Indian River, eastern Cape Breton, Nova Scotia (S. W. Loper, 1903).
Lingulella (Lingulepis) longinervis.
Acrothyra sera?.

13q. (For stratigraphic position and association, see p. 131.) Upper Cambrian: Shales of the ‘‘ Bretonian’’
division of Matthew’s [1903, p. 45] section on Gillis Brook, East Bay, Cape Breton, Nova Scotia (S. W
Loper, 1903).
Orusia lenticularis.
Bradoria robusta (Matthew).

18r (little different horizon from 13i). (For stratigraphic position and association, see p. 132.) Middle Cambrian:
Sandstone of the “‘Johannian”’ division of Matthew’s section on Gillis Brook, East Bay, east of Bras d’Or
Lake, eastern Cape Breton, Nova Scotia (S. W. Loper, 1903).
Lingulella tumida.
Lingulella (Lingulepis) exigua.

i3t. (For stratigraphic position and association, see p. 134.) Middle Cambrian: Sandstones at the base of Divi-
sion E1b of Matthew’s [1903, p. 21] Etcheminian, Dugald Brook, Indian River, eastern Cape Breton, Nova
Scotia (S. W. Loper, 1903).
*Lingulella triparilis. Acrothete prima.
Lingulella tumida. Acrothyra signata.

Bassler cites the following:
Bradoria rugulosa Matthew (emend.).
Bradoria robusta (Matthew).
Bradoria robusta n. var.

13’ (same locality as 10p; see 344k). (Hor stratigraphic position and association, see p. 134.) Middle Cambrian:
Sandstones of Division Elb of Matthew’s[1903, p. 21] Etcheminian, Dugald Brook; Indian River, eastern
Cape Breton, Nova Scotia (S. W. Loper, 1903).
Lingulella triparilis.

13t/’ (see 344m). (For stratigraphic position and association, see p. 134.) Middle Cambrian: Sandstones of Divi-
sions Ele and Bld of Matthew’s [1903, p. 21] Etcheminian, on Dugald Brook, Indian River, eastern Cape
Breton, Nova Scotia (S. W. Loper, 1903).
Lingulella triparilis. Acrothyra signata.
Lingulella (Lingulepis) greswa. Bradoria robusta (Matthew).
Acrothyra sera. Bradoria concinna (Matthew).

184 CAMBRIAN BRACHIOPODA.

Matthew [1903] cites the following as occurring in 1d:

Lingulepis gregwa. Bradorona observator Matthew.

Lingulepis gregwa robusta. Bradorona observator benepuncta Matthew.
Acrotreta papillata=Acrothyra sera. Bradorona perspicator Matthew,

Acrotreta signata tarda=Acrothyra sera. Bradorona spectator Matthew.

Orthotheca sp. Bradorona spectator acuta Matthew.

14. (For stratigraphic position and association, see p. 147.) Middle Cambrian: Limestones overlying the sand~-
stones of the Rome formation, near the wagon road and ina quarry near the railroad track, 7 miles (11.2 km.)
southwest of Rome [see Hayes, 1902, historical geology sheet], Floyd County, Ga. (C. D. Walcott, 1891).
Micromitra (Iphidella) pannula.
Billingsella appalachia?
Dorypyge?.

14a. (For stratigraphic position and association, see p. 147.) Middle Cambrian: Sandstone of the Rome forma-
tion, along First Creek Gap, 4 miles (6.4 km.) north-northeast of Knoxville [Keith, 1905, areal geolozy
sheet], Knox County, Tenn. (M. R. Campbell, 1891).
Micromitra alabamaensis. Lingulella similis.
Obolus willisi. *Wimanella saffordi.
Obolus (Westonia) ella.

14b. Upper Cambrian: Limestone on Cold Creek, at north end of gorge opposite the north end of Sponge Moun-
tain, 2 miles (3.2 km.) south of the San Saba County line, in Llano County, Tex. (J. A. Taff, E. O. Ulrich,
and J. W. Beede).

Obolus matinalis. Acrotreta microscopica.

*Obolus nundina. Billingsella coloradoensis.

Obolus sinoe. Koorthis indianola?.

Lingulella acutangula. Koorthis remnicha texana.
Lingulella upis. Eoorthis wichitaensis.

Lingulella (Lingulepis) acuminata. Eoorthis wichitaensis leeviusculus.

14c. Upper Cambrian: Upper part of the limestone exposed at Baldwin’s ranch, on Cold Creek, 2.5 miles
_ (4 km.) south of the San Saba County line, in Llano County, Tex. (E. O. Ulrich).
Obolus matinalis.

14e (see 14q). Upper Cambrian: Limestone in Bartlett Hollow, 2 miles (3.2 km.) southeast of the mouth of
Falls Creek, Burnet quadrangle (U. 8. G. S.), Lampasas County, Tex. (Bailey Willis, E. O. Ulrich, and
J. A. Taff).
Obolus matinalis.
Obolus sinoe.
Acrotreta microscopica.

14g (=14i). (E. O. Ulrich, J. A. Taff, and J. W. Beede.)
Lingulella upis.
Acrotreta microscopica.
Billingsella coloradoensis.

14i (=14¢). Upper Cambrian: Upper part of limestone exposed 1 mile (1.6 km.) west of Cherokee, San Saba
County, Tex. (E. O. Ulrich, J. A. Taff, and J. W. Beede).
Lingulella acutangula.
*Lingulella upis.
Linnarssonella girtyi.

14k. Upper Cambrian: Limestone on Wolf Creek, 15 miles (24.2 km.) west-southwest of Sheridan, Bighorn
Mountains, Sheridan County, Wyo.
Eoorthis desmopleura. .
*Syntrophia rotundata.

141. (For stratigraphic position and association, see p. 138.) Lower Cambrian: Sandstones about 2,800 feet
(853 m.) below the Middle Cambrian, in a horizon correlated with No. 2j of the Silver Peak group of the
Waucoba Springs section [Walcott, 1908f, p. 187], in the pass about 7 miles (11.2 km.) east of Resting (Fresh-
water) Springs, which is in the southwest corner of T. 21 N., R. 8 E., on Amargosa River, in the south-
eastern part of Inyo County, Cal. (R. B. Rowe, 1901).
*Billingsella bivia.
Olenellus fremonti Walcott

LOCALITIES. 185

14m. (For stratigraphic position and association, see p. 140.) Middle Cambrian: Limestone about 7 miles (11.2
km.) south of Towner’s ranch, Indian Creek, Lincoln County, Nev. (R. B. Rowe, 1901).
Lingulella arguta.

14n. Middle Cambrian: Limestone about 310 feet (94.5 m.) above the Lower Cambrian, on the east side of the
pass about 7 miles (11.2 km.) east of Resting (Freshwater) Springs, which is the southwest corner of
T. 21 N., R.8 E., on Amargosa River, in the southeastern part of Inyo County, Cal. (R. B. Rowe, 1901).
Obolus mcconnelli.
Obolus mcconnelli decipiens.

140. (For stratigraphic position and association, see p. 138.) Lower Cambrian: Sandstones about 3,500 feet (1,067
m.) below the Middle Cambrian, in the pass about 7 miles (11.2 km.) east of Resting (Freshwater) Springs,
which is the southwest corner of T. 21 N., R.8 E., on Amargosa River, in the southeastern part of Inyo
County, Cal. (R. B. Rowe, 1901).
Obolella sp. undt.

14p. (For stratigraphic position and association, see p. 138.) Lower Cambrian: Reddish-brown quartzitic sand-
stone near Resting (Freshwater) Springs, which is in the southwest corner of T. 21 N., R. 8 E., on
Amargosa River, in the southeastern part of Inyo County, Cal. (M. R. Campbell and R. B. Rowe, 1901).

*Lingulella (Lingulepis) rowei. Wanneria gracile Walcott.
Obolella vermilionensis. : Olenellus fremonti Walcott.
Billingsella bivia. Cystid plate.

14q (see 14e). Upper Cambrian: Sandstone in Bartlett Hollow, 1.5 miles (2.4 km.) southeast of the mouth of Falls
Creek, Burnet quadrangle (U. 8. G. 8.), Lampasas County, Tex. (E. O. Ulrich).
Obolus matinalis.

14r. Upper Cambrian: Sandstone in the lower part of the beds exposed on Colorado River, 3 miles (4.8 km.)
south of the northeast corner of Llano County, Tex. (E. O. Ulrich).
Obolus matinalis. ;
Lingulella (Lingulepis) acuminata.

14s. (For stratigraphic position and association, see p. 127.) Middle Cambrian: About 2,300 feet (701 m.) above
the Lower Cambrian and 2,700 feet (823 m.) below the Upper Cambrian, in the Ogygopsis zone of the
Stephen formation [Walcott, 1908f, p. 210], at the great “fossil bed” on the northwest slope of Mount
Stephen, above Field on the Canadian Pacific Railway, British Columbia, Canada (W. D. Wilcox, 1894;
Mr. and Mrs. C. D. Walcott and Mr. and Mrs. L. D. Burling, 1907).

Microm_cra (Iphidella) pannula. Anomalocaris canadensis Whiteaves.

Micromitra (Iphidella) pannula ophirensis. Anomalocaris? whiteavesi Walcott.

*Obolus mcconnelli. Agnostus montis Matthew.

*Obolus septalis. Dorypyge (Kootenia) dawsoni (Walcott).
Acrothele colleni. Bathyuriscus occidentalis (Matthew).

*Acrotreta depressa. Bathyuriscus ornatus Walcott.

*Philhedra columbiana. Bathyuriscus pupa Matthew.

*Nisusia alberta. Bathyuriscus rotundatus (Rominger).
Hyolithellus annulatus (Matthew). Karlia stephenensis Walcott.

Hyolithellus flagellum (Matthew). Neolenus granulatus Matthew=Neolenus serratus.
Orthotheca corrugata Matthew. Neolenus serratus (Rominger).

Orthotheca major Walcott. Ogygopsis klotzi (Rominger).

Hyolithes carinatus Matthew. Oryctocephalus reynoldsi Reed.

Hyolithes sp. Oryctocephalus walkeri Matthew=Oryctocephalus rey-
Stenotheca wheeleri Walcott. noldsi. E
Platyceras bellianus Walcott. Burlingia hectori Walcott.

Platyceras romingeri Walcott. Ptychoparia cordillerze (Rominger).

Scenella varians Walcott. Ptychoparia palliseri Walcott.

Anomalocaris?? acutangula Walcott. Zacanthoides spinosus' (Walcott).

14t. (For stratigraphic position and association, see p.157.) Middle Cambrian: Limestone lying on slope between
the Cambrian quartzite and the massive blue limestone 100 feet (30.5 m.) above, Mount Nebo Canyon,
3 miles (4.8 km.) southeast of Mona, Juab County, Utah (F. B. Weeks, 1903).
Micromitra (Iphidella) pannula.
Lingulella cf. similis.
_ *Acrotreta neboensis.

186 CAMBRIAN BRACHIOPODA.

14v. (Forstratigraphic position and association, see p. 156.) Middle Cambrian: Shales of unknown stratigraphic
horizon collected 1 mile (1.6 km.) south of Rainbow Valley, House Range [see Walcott, 1908f, Pl. XIII],
Millard County, Utah.
Obolus meconnelli.

14x. Middle Cambrian: About 400 feet (122 m.) above the bottom of Tombstone Gulch, in the Abrigo limestone
[Ransome, 1904, p. 3], in the northwest suburb of Bisbee [see Ransome, 1904, areal geology sheet], Cochise
County, Ariz. (F. L. Ransome, 1903).
Obolus tetonensis.
Billingsella??.

15b. (For stratigraphic position and association, see p. 156.) Middle Cambrian: About 1,700 feet (518.2 m.) above
the Lower Cambrian and 2,700 feet (823 m.) below the Upper Cambrian, in the shaly limestones and calcareous
shales of the Wheeler formation [Walcott, 1908f, p. 181], near Swasey Spring, House Range [Walcott, 1908f,
Pl. XIII], Millard County, Utah (G. K. Gilbert, 1903).
Acrothele subsidua. :

15¢e. (For stratigraphic position and association, see p. 156.) Middle Cambrian: Marjum limestone [Walcott,
1908a, p. 10], near Swasey Spring, House Range [Walcott, 1908f, Pl. XIII], Millard County, Utah (G. K.
Gilbert, 1901).
Nisusia (Jamesella) nautes?.
Anomocare sp.

15d (same horizon as 33d). (For stratigraphic position and association, see p. 154.) Upper Cambrian: Thin-
bedded blue limestone near Cave Spring, on the east side of the Fish Spring Range, about 4 miles (6.4 km.)
south of the J. J. Thomas ranch, Juab County, Utah (G. K. Gilbert, 1901).
Lingulella desiderata. Acrotreta idahoensis.
*Lingulella isse. Acrotreta idahoensis alta.
Lingulella manticula.

15p. (For stratigraphic position and association, see p. 155.) Middle Cambrian: Limestones near the north end
of the Fish Spring Range, Tooele County, Utah (G. K. Gilbert, 1901).
Obolus meconnelli pelias.
Lingulella desiderata.

15r. Middle Cambrian: Dark argillaceous shale at Khussak, Salt Range, India (F. Noetling, 1902).
*Lingulella fuchsi. *Botsfordia granulata.
*Lingulella wanniecki. Redlichia neetlingi Cossman.

15x. (For stratigraphic position and association, see p. 155.) Middle Cambrian: Limestones near the middle of
the Fish Spring Range, near the line between Juab and Tooele counties, Utah (G. K. Gilbert, 1901).
Obolus mcconnelli pelias.
Lingulella desiderata.

16. (For stratigraphic position and association, see p. 147.) Middle Cambrian: Limestones in Conasauga (‘‘Coosa ’’)
limestone, Blountsville Valley, Blount-County, Ala.
Lingulella desiderata.
*Lingulella nanno.
Dicellomus appalachia.

16f (see 47d-f). Lower Cambrian: Sandstone at the mouth of Little Antietam Creek, near Hakles Mills, Wash-
ington County, Md. (John Widgeon, 1903).
Obolella minor. ~
Syntrophia sp. undt.

16h (see 334h). (For stratigraphic position and association, see p. 145.) Middle Cambrian: Limestones of Para-
doxides forchhammeri zone at Borregaard, Bornholm Island, Denmark (K. A. Grénwall, 1903).
*Micromitra pusilla. Acrothele intermedia.
Micromitra (Iphidella) ornatella. Acrotreta sagittalis.
Obolus schmalenseei. Acrotreta schmalenseei.
Lingulella ferruginea. Anomocare leve Angelin.
Acrothele coriacea.

16i. (For stratigraphic position and association, see p. 146.) Middle Cambrian: Limestones of ‘‘ Conocoryphe
exsulans”’ zone at Borregaard, Bornholm Island, Denmark (K. A. Grénwall, 1903).
Obolus schmalenseei. Acrotreta sagittalis.
Lingulella?. Liocephalus impressa Linnarsson.

LOCALITIES. -

16}.

187

(For stratigraphic position and association, see p. 145.) Middle Cambrian: Limestones of Paradozides forch-

hammeri zone at Laesadi, Bornholm Island, Denmark (K. A. Grénwall, 1903).

Micromitra pusilla.
Lingulella ferruginea.
Acrothele coriacea.

16k.

Acrotreta sagittalis.
Acrotreta schmalenseei.

(For stratigraphic position and association, see p. 146.) Middle Cambrian: Limestones of Paradoxides

davidis zone at Laesaa, Bornholm Island, Denmark (K. A. Grénwall, 1903).

Acrothele coriacea.
Acrotreta sagittalis.

oy

161.

(For stratigraphic position and association, see p. 146.) Middle Cambrian: Limestones of Paradoxides

davidis zone at Borregaard, Bornholm Island, Denmark (K. A. Grénwall, 1903).

Acrothele coriacea.
Acrotreta sagittalis.

16n.

Upper Cambrian: Interformational conglomerate and shales in Adams pasture, 0.5 mile (0.8 km.) west

of Main Street, on Lake Street, St. Albans, Franklin County, Vt. (Geo. H. Edson; H. EH. Dickhaut, 1903).

Lingulella?.
Lingulella (Lingulepis) acuminata.
Yorkia sp.

160.

Lingulella concinna.

17b. (For stratigraphic position and association,

(For stratigraphic position and association, see p. 131.) Upper Cambrian: Shales on McMullins Brook, in
the Hast Boisdale district, eastern Cape Breton,

Nova Scotia (S. W. Loper, 1903).

see p. 147.) Lower Cambrian: Rome (‘‘Monteyallo”)

formation 4 miles (6.4 km.) south of Helena, Shelby County, Ala. (C. D. Walcott, 1895).

Micromitra (Paterina) major.
Micromitra (Paterina) williardi.
17c.
north of Last Chance copper mine, south side of
*Obolus (Westonia) themis.

Lingulella acutangula.
Lingulella lineolata.

17j.
Lingulella similis.

Obolus smithi.
*Wimanella shelbyensis.

Middle Cambrian: Sandy limestone 235 feet (71.6 m.) above the ‘‘Tonto” sandstone, Grand View trail

the Grand Canyon of the Colorado, Arizona.

Middle Cambrian: Limestone in the east end of the town of Galena, Black Hills, South Dakota.

17k. Middle Cambrian: Limestone thrown out on the dump of the Great Northern shaft, southeast of Twobit,
northern Black Hills, Lawrence County, South Dakota.

Linnarssonella girtyi.

18.

(For stratigraphic position and association, see p.

147.) Middle Cambrian: Limestone 1 mile (1.6 km.) east

of Gap Creek, 13 miles (20.8 km.) 8. 75° E. of Knoxville, Knox County, Tenn. (A. Keith and C. D. Walcott).

Acrotreta kutorgai?.

20 (see 21a). Lower Cambrian: Limestone on the south side of Mettawee River, 0.25 mile (0.4 km.) above the
North Granville bridge, Fort Ann quadrangle (U.S. G. 8.), Washington County, N. Y. (C. D. Walcott,

1890).
Obolella crassa.
Medusa? sp.

20a.

Lower Cambrian: Gray limestone interbedded with shaly slates in a lane west of Lafayette Stevens’s house,

about 100 yards (91.4 m.) from the main road in the southern part of Whitehall township, Fort Ann quad-

rangle (U.S. G. S.), Washington County, N. Y.
Lingulella granvillensis.
Acrotreta sagittalis taconica.
Hyolithellus micans (Billings).
Microdiscus connexus Walcott.

21. Lower Cambrian: Shales 1.5 miles (2.4 km.) south
County, N. Y. (C. D. Walcott, 1890).

Billingsella salemensis.

Archzocyathus dwighti Walcott.

Stenotheca rugosa (Hall).

Fordilla troyensis Barrande.

(C. D. Walcott, 1890).
Olenellus?.

Olenoides fordi Walcott.
Ptychoparia sp.

of Salem, Cambridge quadrangle (U.S. G. S.), Washington

Microdiscus lobatus (Hall).
Olenellus.

Solenopleura? tumida Walcott.
Leperditia? dermatoides (Walcott).

188 CAMBRIAN BRACHIOPODA.

21a. Lower Cambrian: Limestone below the first fall of Mettawee River, above the North Granville bridge,
Fort Ann quadrangle (U. 8. G. S.), Washington County, N. Y. (C. D. Walcott, 1890).

Lingulella granvillensis.
Microdiscus connexus Walcott.

Olenellus?.
Ptychoparia sp.

22. Lower Cambrian: Limestone 1.5 miles (2.4 km.) north of North Granville, Fort Ann quadrangle (U.S. G. S.),,
Washington County, N. Y. (C. D. Walcott, 1891).

Acrothele nitida.
Acrotreta sagittalis taconica.
Hyolithellus micans (Billings).

Microdiscus lobatus (Hall).
Olenellus.

22a. Lower Cambrian: Limestone in Penrhyn quarries, Middle Granville, Mettawee quadrangle (U. 8S. G. S.),
Washington County, N. Y. (C. D. Walcott, 1890).

Lingulella sp.
Acrotreta sagittalis taconica.
Billingsella salemensis.

25. Lower Cambrian: Sandstone just above Parker’s quarry, near Georgia, Franklin County, Vt. (C. D. Walcott.

and Cooper Curtice, 1883).
*Rustella edsoni.
Micromitra (Paterina) bella.
Nisusia festinata.
*Nisusia festinata transversa.
Medusa? sp.
Eocystites? sp.
*Mesonacis vermontana (Hall).
*Peedeumias transitans Walcott.

*Olenellus thompsoni (Hall).

Olenellus thompsoni crassimarginatus Walcott.
Microdiscus parkeri Walcott.

Ptychoparia adamsi (Billings).

Ptychoparia vuleanus (Billings).

Protypus senectus (Billings).

Bathynotus bolopyga (Hall).

Olenoides marcoui (Whitfield).

25a. Lower Cambrian: Limestone on the Hall (Donaldson’s) farm, 2 miles (3.2 km.) east of Swanton, Franklin.

County, Vt. (C. D. Walcott and Cooper Curtice,
*Micromitra (Paterina) labradorica swantonensis.
Obolus ef. prindlei.
Lingulella granvillensis.
Kutorgina cingulata.
Nisusia festinata.
Nisusia festinata transversa.

26. Lower Cambrian: Sandstone northeast of the Corman farm buildings, east of Highgate Springs, Franklin

County, Vt. (C. D. Walcott and Cooper Curtice,
Micromitra (Paterina) labradorica swantonensis.
Nisusia festinata.
Billingsella orientalis.
Scenella varians Walcott.
Hyolithes sp.

1883).

Billingsella orientalis.
Hyolithes sp.

Salterella pulchella Billings.
Olenellus thompsoni (Hall).
Ptychoparia adamsi (Billings).
Protypus senectus (Billings).

1883).

Olenoides desiderata (Walcott).
Ptychoparia adamsi (Billings).
Ptychoparia teucer (Billings).
Ptychoparia vulcanus (Billings).
Ptychoparia sp.

27. Lower Cambrian: Even-bedded and conglomerate limestones on the ridge in the eastern suburb of Troy,,
Troy quadrangle (U. 8. G. 8.), Rensselaer County, N. Y. (Cooper Curtice, 1883).

Obolella crassa.

Bicia gemma.

Botsfordia ceelata.

*Acrothele nitida.

Archzocyathus rarus-(Ford).
Archeocyathus rensseleericum (Ford).
Scenella retusa Ford.

Stenotheea rugosa (Hall).

Platyceras primevum Billings.
Hyolithellus micans Billings.

Hyolithes americanus Billings.
Hyolithes communis Billings.
Hyolithes communis emmonsi Ford.
Hyolithes impar Ford.

Hyolithes sp.

Microdiscus lobatus (Hall).
Microdiscus speciosus Ford.
Elliptocephala asaphoides Emmons.
Olenoides fordi Walcott.
Solenopleura nana Ford.

27a. Lower Cambrian: Reddish sandstone about 1 mile (1.6 km.) east of Lansingburg, north of Troy, Cohoes:

quadrangle (U. S. G. S.), Rensselaer County, N.

Obolella crassa.

Y. (Cooper Curtice, 1883).

LOCALITIES. 189

28. Upper Cambrian: Shales about 100 feet (30.5 m.) above the Olenellus horizon, south of Highgate Falls, 0.25
mile (0.4 km.) east of Swanton, Franklin County, Vt. (C. D. Walcott, 1884).
*Protorthis wingi.
Hyolithes sp.
Ptychoparia adamsi (Billings. )

28a. Middle? Cambrian: ‘St. Albans formation,” in limestone lentile about 1 mile (1.6 km.) east of Parkez’s
quarry, near Georgia, Franklin County, Vt. (C. D. Walcott, 1884).
Lingulella franklinensis.
*Huenella billingsi.
Ptychoparia adamsi (Billings).

29 (see 338b). Lower Cambrian: Limestone just above the bridge at the Stockport paper mill, on Kinderhook
Greek, Columbia County, N. Y. (C. D. Walcott and S. W. Ford).
‘Obolus prindlei.
Lingulella granvillensis.
Acrotreta sagittalis taconica.

29a (see 338). Lower Cambrian: Limestone 1 mile (1.6 km.) below the New York Central Railroad depot at
Schodack Landing, Rensselaer County, N. Y. (C. D. Walcott and S. W. Ford).

Obolella crassa. Hyolithes americanus Billings.
Botsfordia celata. Microdiscus lobatus (Hall).

Bicia gemma. Microdiscus speciosus Ford.
Acrotreta sagittalis taconica. Elliptocephala asaphoides Emmons.

Hyolithellus micans (Billings).

30. (For stratigraphic position and association, see p. 158.) Lower Cambrian: Limestone 8 miles (12.8 km.) north
of Bennetts Spring, on the west slope of the Highland Range, Lincoln County, Nev. (C. D. Walcott and
J. EH. W., 1885).

Micromitra (Iphidella) pannula. Olenellus gilberti (Meek).
Obolus (Westonia) ella. Peachella iddingsi Walcott.
Billingsella highlandensis. Sponge?.

Callavia nevadensis Walcott. Crepicephalus augusta Walcott.
‘Olenellus fremonti Walcott. Crepicephalus liliana Walcott.

30a. (For stratigraphic position and association, see p. 158.) Middle Cambrian: Shale on north side of Big Cotton-
wood Canyon, 1 mile (1.6 km.) below Argenta, in the Wasatch Mountains, southeast of Salt Lake City,
Salt Lake County, Utah (C. D. Walcott and J. E. W., 1885).

Micromitra (Iphidella) pannula. Tsoxys argentea (Walcott).

Obolus (Westonia) ella. Ptychoparia quadrans (Hall and Whitfield).
Lingulella helena. Bathyuriscus productus (Hall and Whitfield).
Hyolithellus sp. Olenoides wasatchensis (Hall and Whitfield).

Hyolithes billingsi Walcott.
Walcott [1886] wrongly includes Cruziana and Olenellus gilberti in this fauna (see Walcott, 1891b, p. 319}.

30c (—llw). (For stratigraphic position and association. see p. 157.) (C. D. Walcott, F. B. Weeks, and L. D.
Burling, 1905.)
Micromitra (Paterina) labradorica utahensis.
Ptychoparia 2 sp.

30d. (For stratigraphic position and association, see p.157.) Middle Cambrian: About 1,020 feet (310.9 m.) above
the Lower Cambrian and 3,400 feet (1,036.3 m.) below the Upper Cambrian, in the limestone forming le of
the Swasey formation [Walcott, 1908f, p. 182], at the head of Dome Canyon, about 2 miles (3.2 km.) west-
southwest of Antelope Springs, House Range [Walcott, 1908f, Pl. XIII], Millard County, Utah (F. B.
Weeks, 1905).
‘Obolus (Westonia) ella.
Ptychoparia, several species.

30e. (For stratigraphic position and association, see p. 158.) Middle Cambrian: About 100 feet (30.5 m.) above
the Lower Cambrian and 4,300 feet (1,310.6 m.) below the Upper Cambrian, in the limestones forming la of
the Langston (?) limestone [Walcott, 1908f, p. 183], in Dome Canyon, House Range [Walcott, 1908f,
Pl. XIII], Millard County, Utah (C. D. Walcott, F. B. Weeks, and L. D. Burling, 1905).
Billingsella sp. undt. Zacanthoides.
Hyolithes. Ptychoparia.
Leperditia?. Dorypyge?.

190 CAMBRIAN BRACHIOPODA.

30g (=11q and lly; same horizon as 3w). (For stratigraphic position and association, see p. 156.) Middle Cam-
brian: About 2,350 feet (716.3 m.) above the Lower Cambrian and 2,050 feet (624.8 m.) below the Upper
Cambrian, in the limestone forming 1c of the Marjum limestone [Walcott, 1908f, p. 180], 2.5 miles (4 km.)
east of Antelope Springs, in ridge east of Wheeler Amphitheater [Walcott, 1908f, Pls. XIII andXV], House
Range, Millard County, Utah (C. D. Walcott, F. B. Weeks, and L. D. Burling, 1905).

Obolus mcconnelli pelias. Agnostus 2 sp.

Acrothele subsidua. , Ptychoparia 3 sp.

Acrotreta ophirensis. Solenopleura.

Acrotreta cf. ophirensis. Neolenus inflatus Walcott.
Hyolithes. Neolenus intermedius Walcott.
Crinoidal fragments. Neolenus intermedius pugio Walcott.
Sponge. Neolenus superbus Walcott.
Ogygopsis?.

30h. (For stratigraphic position and association, see p. 154.) Upper Cambrian: About 350 feet (106.7 m.) above
the Middle Cambrian and 2,950 feet (899.2 m.) below the top of the Upper Cambrian, near the base of the
arenaceous limestones forming 2a of the Orr formation [Walcott, 1908f, p. 177], on Orr Ridge, about 5 miles
(8 km.) south of Marjum Pass, House Range [Walcott, 1908f, Pl. XIII], Millard County, Utah (F. B.
Weeks, 1905).

Lingulella desiderata. Crepicephalus texanus (Shumard).
Acrotreta idahoensis. Bathyuriscus.
Acrotreta idahoensis sulcata. ; Ilzenurus?.

30j. (For stratigraphic position and association, see p. 154.) Upper Cambrian: About 950 feet (289.6 m.) above
the Middle Cambrian and 2,450 feet (746.8 m.) below the top of the Upper Cambrian, near the base of the
arenaceous shales and limestones forming le of the Orr formation [Walcott, 1908f, p. 176], on Orr Ridge,
about 5 miles (8 km.) south of Marjum Pass, House Range [Walcott, 1908f, Pl. XIII], Millard County,
Utah (C. D. Walcott, F. B. Weeks, and L. D. Burling, 1905).

Micromitra (Paterina) crenistria. *Linnarssonella transversa.
Obolus mcconnelli pelias. Agnostus.
Lingulella desiderata. Crepicephalus.

Lingulella isse. Y

30k (25 feet below 31t at same locality). (For stratigraphic position and association, seep. 154.) Upper Cambrian:
1,150 feet (350.5 m.) above the Middle Cambrian and 2,175 feet (662.9 m.) below the top of the Upper Cam-
brian, at the top of the arenaceous shales and limestones forming le of the Orr formation [Walcott, 1908f,
p. 176], on Orr Ridge, about 5 miles (8 km.) south of Marjum Pass, House Range [Walcott, 1908f, Pl. XIII],
Millard County, Utah (C. D. Walcott, F. B. Weeks, and L. D. Burling, 1905).

Lingulella desiderata. Ptychoparia?.
Lingulella isse. Solenopleura.
*Linnarssonella modesta.

301 (30y is the metamorphosed equivalent of this at different locality). (For stratigraphic position and association,
see p. 153.) Upper Cambrian: About 1,400 feet (426.7 m.) above the Middle Cambrian and 1,900 feet (579.1
m.) below the top of the Upper Cambrian, in the shales forming 1b of the Orr formation [Walcott, 1908t,
p- 176], on Orr Ridge, about 5 miles (8 km.) south of Marjum Pass [Walcott, 1908f, Pl. XIII], House
Range, Millard County, Utah (C. D. Walcott, F. B. Weeks, and L. D. Burling, 1905).
Lingulella manticula. Ptychaspis.
Section of crinoid column. Anomocare.

30m. (Forstratigraphic position and association, see p. 153.) Upper Cambrian: About 1,950 feet (584.4 m.) above the
Middle Cambrian and 1,350 feet (411.5 m.) below the top of the Upper Cambrian, in the siliceous limestones
forming le of the Notch Peak limestone [Walcott, 1908f, p. 175], on the slopes of Notch Peak, about 5 miles
(8 km.) southwest of Marjum Pass, House Range [Walcott, 1908f, P!. XIII], Millard County, Utah (C. D.
Walcott, F. B. Weeks, and L. D. Burling, 1905).
*Obolus tetonensis leda.

30n (=30n’). (Forstratigraphic position and association, see p. 155.) Middle Cambrian: About 3,750 feet (1,143 m.)
above the Lower Cambrian and 659 feet (198 m.) below the Upper Cambrian, in the shaly limestones form-
ing Ic of the Weeks limestone [Walcott, 1908f, p. 175], on the north side of Weeks Canyon, about 4 miles
(6.4 km.) south of Marjum Pass, House Range [Walcott, 1908f, Pl. XIII], Millard County, Utah (C. D. Wal-
cott and L. D. Burling, 1905).

‘*Obolus (Fordinia) perfectus. Ptychoparia, several speties.
Lingulella isse. Asaphiscus sp.

Acrotreta ophirensis. Crepicephalus texanus (Shumard).
*Acrotreta ophirensis descendens. Neolenus.

Hyolithes. Solenopleura.

Agnostus, several species.

LOCALITIES. 191

30n/ (=30n, but in slightly higher beds). (For stratigraphic position and association, see p. 155.) (C. D. Walcott
and L. D. Burling, 1905.)

300 (=14v). (For stratigraphic position and association, see p. 154.) Middle Cambrian: About 3,950 feet (1,204 m.)
_ above the Lower Cambrian and 450 feet (137.2 m.) below the Upper Cambrian, in the shaly limestones form-
ing 1b of the Weeks limestone [Walcott, 1908f, p. 178], on the north side of Weeks Canyon, about 4 miles
(6.4 km.) south of Marjum Pass, House Range [Walcott, 1908f, Pl. XIII], Millard County, Utah (C. D. Wal-
cott and L. D. Burling, 1905).

Obolus (Fordinia) perfectus. Crepicephalus texanus (Shumard).
Asaphiscus sp. Bathyuriscus.
Agnostus, several species. Anomocare?.
Ptychoparia. Solenopleura.

30p. (For stratigraphic position and association, see p.151.) Middle Cambrian: About 125 feet (38 m.) above the
Cambrian quartzitic sandstones on the north side of Ogden Canyon, about 1 mile (1.6 km.) above its mouth,
east of Ogden, Weber County, Utah (F. B. Weeks and L. D. Burling, 1905).
Micromitra (Paterina) labradorica utahensis.
' Obolus meconnelli.
Obolus (Westonia) ella.

30q. (For stratigraphic position and association, see p. 149.) Upper Cambrian: Limestones about 2,300 feet (701
m.) above the Cambrian quartzitic sandstones on pipe line above limekiln in Ogden Canyon, 1 mile
(1.6 km.) above its mouth, east of Ogden, Weber County, Utah (F. B. Weeks and L. D. Burling, 1905).
Obolus rotundatus.
Lingulella manticula.

30s. (For stratigraphic position and association, see p. 149.) Upper Cambrian: Green shale about 1,200 feet
(365.8 m.) above the Cambrian quartzitic sandstones on pipe line above limekiln in Ogden Canyon, 1 mile
(1.6 km.) above its mouth, east of Ogden, Weber County, Utah (L. D. Burling, 1905).
Lingulella isse.

30u. (For stratigraphic position and association, see p.151.) Middle Cambrian: Sandy shales about 250 feet (76.2
m.) above the top of the Cambrian quartzitic sandstones 4 miles (6.4 km.) northwest of Promontory Point
station (on the “‘Lucin cut-off” of the Union Pacific Railway), about halfway up west end of ridge, north of
Great Salt Lake, Boxelder County, Utah (F. B. Weeks, 1905).
Micromitra (Paterina) labradorica utahensis.
Acrotreta cf. ophirensis.

30w. (For stratigraphic position and association, see p. 153.) Upper Cambrian: Drift bowlder of limestone supposed
to have come from the beds forming la of the Notch Peak limestone on Notch Peak [Walcott, 1908f, p.
175], found about 2 miles (3.2 km.) south of Marjum Pass, House Range [Walcott, 1908f, Pl. XIII], Millard
County, Utah (C. D. Walcott and F. B. Weeks, 1905).

Schizambon typicalis. Solenopleura.
Eoorthis desmopleura. Illzenurus.
Agraulos.

30y (the metamorphosed equivalent of 301 at a different locality). (For stratigraphic position and association, see

p. 153.) Upper Cambrian: About 1,400 feet (426.7 m.) above the Middle Cambrian and 1,900 feet (579.1 m.)
below the top of the Upper Cambrian, in the supposed metamorphosed equivalent of the shales forming 1b
of the Orr formation [Walcott, 1908f, p. 176], above the granite contact on top of the ridge north of Notch .
Peak [Walcott, 1908f, Pls. XIII and XIV], House Range, Millard County, Utah (C. D. Walcott, F. B.
Weeks, and L. D. Burling, 1905).

Obolus rotundatus.

Lingulella isse.

Anomocare.

80z. (For stratigraphic position and association, seep. 156.) Middle Cambrian: About 2,450 feet (746.8 m.) above

the Lower Cambrian and 1,950 feet (594.4 m.) below the Upper Cambrian, in the upper part of the limestone
forming le of the Marjum limestone [Walcott, 1908f, p. 180], in the long cliff about 2 miles (3.2 km.) south-
east of Marjum Pass, House Range [Walcott, 1908i, Pls. XIII and XV], Millard County, Utah (C. D.
Walcott, F. B. Weeks, and L. D. Burling, 1905).

Acrotreta pyxidicula.

Agnostus.

Ptychoparia.

192 -CAMBRIAN BRACHIOPODA.

31. (For stratigraphic position and association, see p. 158.) Middle Cambrian: Shales at the Chisholm mine,
southwest slope of Ely Mountains, 3 miles (4.8 km.) northwest of Pioche, Lincoln County, Nev. (C. D.
Walcott and J. E. W., 1885).

Micromitra (Iphidella) pannula. Zacanthoides typicalis (Walcott).

Obolus (Westonia) ella. Ptychoparia piochensis Walcott.

*Lingulella dubia. Anomocare parvum Walcott.

EKocystites longidactylus Walcott. Bathyuriscus howelli Walcott.

Hyolithes billingsi Walcott. Bathyuriscus productus (Hall and Whitfield).

31a. (For stratigraphic position and association, seep. 158.) Lower Cambrian: Limestone and interbedded sili-
ceous shales of the Pioche formation [Walcott, 1908a, p. 11], just above the quartzite on the east side of the
anticline, near Pioche, Lincoln County, Nev. (C. D. Walcott and J. E. W., 1885).

*Micromitra (Iphidella) pannula. *Olenellus gilberti (Meek).

*Acrothele spurri. : Olenoides sp.

*Acrothele subsidua hera. Oryctocephalus primus Walcott.

*Acrotreta primzva. Zacanthoides levis (Walcott).

*Billingsella highlandensis. Crepicephalus augusta Walcott. :
Hyolithes billingsi Walcott. Crepicephalus liliana Walcott.

Bellerophon antiquatus Whitfield. Ptychoparia sp.

~ 81c (=540; same horizon as 32e). (For stratigraphic position and association, see p. 151.) Middle Cambrian: About

900 feet (274.3 m.) above the Brigham quartzite and 3,300 feet (1,006.5 m.) below the Upper Cambrian, in
the limestone forming 1b of the Ute limestone [Walcott, 1908f, p. 196], in Blacksmith Fork Canyon, about
10 miles (16.1 km.) east of Hyrum, Cache County, Utah (L. D. Burling, 1905).

Obolus mcconnelli. Syntrophia cambria.

Acrotreta cf. ophirensis. Zacanthoides.

Acrotreta sp. undt. Ptychoparia subcoronata (Hall and Whitfield).

Otusia utahensis. Dorypyge ? quadriceps (Hall and Whitfield).

EKoorthis zeno.

31d (=541). (For stratigraphic position and association, see p. 152.) Middle Cambrian: About 500 feet (152.4 m.)
above the Brigham quartzite and 3,700 feet (1,127.8 m.) below the Upper Cambrian, in the Spence shale
member of the Ute limestone [Walcott, 1908f, p. 197], in Blacksmith Fork Canyon, about 10 miles (16.1
km.) east of Hyrum, Cache County, Utah (F. B. Weeks, 1905).
Obolus (Westonia) ella?.
Ptychoparia.

8le (=54a). (For stratigraphic position and association, see p. 151.) Middle Cambrian: About 750 feet (228.6 m.)
above the Brigham quartzite and 3,440 feet (1,048.5 m.) below the Upper Cambrian, in the shales forming
2a of the Ute limestone [Walcott, 1908f, p. 196], in Blacksmith Fork Canyon, about 10 miles (16.1 km.) east
of Hyrum, Cache County, Utah (L. D. Burling, 1905).

Obolus (Westonia) ella.
Ptychoparia. —

31h (=55n). (For stratigraphic position and association, see p. 150.) (F. B. Weeks, 1905.)

811 (=54h). (For stratigraphic position and association, see p. 149.) Middle Cambrian: About 3,140 feet (957.1
m.) above the Brigham quartzite and 1,050 feet (320 m.) below the Upper Cambrian, in the limestones
forming 1a of the Bloomington formation [Walcott, 1908f, p. 194], in Blacksmith Fork Canyon, about 9 miles
(14.4 km.) east of Hyrum, Cache County, Utah (L. D. Burling, 1905).

Lingulella desiderata.
Agnostus. “

81m (=55h). (For stratigraphic position and association, see p. 149). Upper Cambrian: About 175 feet (53.3 m.)
above the Middle Cambrian and 1,050 feet (320 m.) below the top of the Upper Cambrian, near the base of
the limestones forming 3 of the St. Charles limestone [Walcott, 1908f, p. 192], im Blacksmith Fork Canyon,
about 9 miles (14.4 km.) east of Hyrum, Cache County, Utah (L. D. Burling, 1905).

Obolus sp. undt. Agnostus.
Lingulella manticula. Ptychoparia.
Billingsella coloradoensis.

81n (=55g). (For stratigraphic position and association, see p. 149.) Upper Cambrian: About 250 feet (76.2 m.)
above the Middle Cambrian and 975 feet (297.2 m.) below the top of the Upper Cambrian, in the upper part
of the limestone forming 3 of the St. Charles limestone [Walcott, 1908f, p. 192], in Blacksmith Fork Canyon,
about 9 miles (14.4 km.) east of Hyrum, Cache County, Utah (L. D. Burling, 1905).

Acrotreta? sp.
Anomocare.

LOCALITIES. 193

81g. (For stratigraphic position and association, see p. 153.) Upper Cambrian: About 2,800 feet (853.4 m.) above
the Middle Cambrian and 500 (152.4 m.) below the top of the Upper Cambrian, in the gray limestone forming
la of the Notch Peak limestone [Walcott, 1908f, p. 175], north slope of Notch Peak, House Range [Walcott,
1908f, Pls. XIII and XIV], Millard County, Utah (F. B. Weeks, 1905).
Lingulella isse.
Dikellocephalus?.

31s. (Forstratigraphic position and association, see p. 157.) Middle Cambrian: 490 feet (149.4 m.) above the Lower
Cambrian and 3,925 feet (1,196.3 m.) below the Upper Cambrian, in the pinkish argillaceous shale forming
1d of the Howell formation [Walcott, 1908f, p. 182], south side of Dome Canyon, about 1 mile (1.6 km.) below
the divide and 3 miles (4.8 km.) west-southwest of Antelope Springs, House Range [Walcott, 1908f, Pl.
XIII], Millard County, Utah (C. D. Walcott and F. B. Weeks, 1905).

Micromitra (Iphidella) pannula. Scenella.
Obolus (Westonia) ella. Hyolithes.
Acrothele spurri. Zacanthoides.
Acrotreta cf. ophirensis. Bathyuriscus.

31t (25 feet above 30katsame locality). (For stratigraphic position and association, see p. 154.) Upper Cambrian:
About 1,175 feet (358.1 m.) above the Middle Cambrian and 2,150 feet (655.3 m.) below the top of the Upper
Cambrian, in the limestone forming 1d of the Orr formation [Walcott, 1908f, p. 176], on Orr Ridge, about 5
miles (8 km.) south of Marjum Pass, House Range [Waleott, 1908f, Pl. XIII], Millard County, Utah (L. D.
Burling, 1905).
Linnarssonella modesta. Solenopleura.
*Linnarssonella nitens. Protaspis.

31u. (For stratigraphic position and association, see p. 158.) Middle Cambrian: Shales on west slope of spur facing
the main part of the Highland Range, 3 miles (4.8 km.) northwest of Pioche, Lincoln County, Nev.

Walcott [1891b, p. 318] cites the following species from this locality:

Lingulella ella=Obolus (Westonia) ella. Ptychoparia piochensis Walcott.

Kutorgina pannula—Micromitra (Iphidella) pannula. Zacanthoides typicalis (Walcott).
Eocystites?? longidactylus Walcott. Bathyuriscus howelli Walcott.

Hyolithes billingsi Walcott. Bathyuriscus productus (Hall and Whitfield).

8lv. (For stratigraphic position and association, see p. 157.) Middle Cambrian: 650 feet (198.1 m.) above the
Lower Cambrian and 3,750 feet (1,143 m.) below the Upper Cambrian, in shales at the top of the limestone
forming la of the Howell formation [Walcott, 1908f, p. 182], northeast side of Dome Canyon, about 4 miles
(6.4 km.) west-southwest of Antelope Springs, House Range [Walcott, 1908f, Pls. XIII and XVI], Millard
County, Utah (C. D. Walcott, F. B. Weeks, and L. D. Burling, 1905).
Micromitra (Iphidella) pannula.
Acrotreta cf. ophirensis.
Ptychoparia.
3ly. (Forstratigraphic position and association, see p.151.) Middle Cambrian: Thin-bedded limestone about 125
feet (38 m.) above the Cambrian quartzitic sandstones in the Wasatch Mountains, 1 mile (1.6 km.) north-
west of Geneva (Copenhagen), east of Brigham, Boxelder County, Utah (F. B. Weeks and L. D. Burling,
1905).
Obolus mcconnelli.
Lingulella isse.
31z (=55t). (For stratigraphic position and association, see p. 151.) Middle Cambrian: About 350 feet (106.7 m.)
above the Brigham quartzite, in the limestone of the Ute limestone [Walcott, 1908a, p. 7], on west side
of road, 0.5 mile (0.8 km.) above the forks, Paradise Dry Canyon (Hoeellyy known as East Fork), east of Para-
dise, Cache County, Utah (F. B. Weeks, 1905).
Otusia utahensis.
Acrotreta ophirensis.
32. Lower Cambrian: Sandstone on the south slope of Stissing Mountain, Dutchess County, N. Y. (C. D. Wal-
cott, 1886).
*Obolella minor.
Obolella sp.
Elliptocephala asaphoides Emmons.
82a. Lower Cambrian: Limestone, 0.75 mile (1.2 km.) west of Riders Mill station on the Harlem Extension Rail-
road, about 9 miles (14.4 km.) north-northeast of Chatham, Kinderhook quadrangle (U.S. G. 8.), Colum-
bia County, N. Y. (C. D. Walcott and T. N. Dale, 1891).
Bicia gemma.
Acrotreta sagittalis taconica.
62667°—vot 51, pr 1—12_13

194 CAMBRIAN BRACHIOPODA.

82c. (For stratigraphic position and association, see p. 152.) Middle Cambrian: About 60 feet (18.3 m.) above the
Brigham quartzite [Walcott, 1908a, p. 8], in green shale 1 mile (1.6 km.) northwest of Geneva (Copen-
hagen), east of Brigham, Boxelder County, Utah (L. D. Burling, 1905).
Acrotreta cf. ophirensis.

32d. (For stratigraphic position and association, see p. 152.) Middle Cambrian: Shales about 150 feet (45.7 m.)
above the Brigham quartzite [Walcott, 1908a, p. 8], on the east side of the south fork of Paradise Dry Canyon
(locally known as East Fork), east of Paradise, Cache County, Utah (F. B. Weeks, 1905).
Micromitra (Paterina) labradorica utahensis.
Obolus (Westonia) ella.

32e (same horizon as 3lc and 540). (For stratigraphic position and association, see p. 151.) Middle Cambrian:
About 900 feet (274.3 m.) above the Brigham quartzite and 3,300 feet (1,005.8 m.) below the Upper Cambrian,
in limestone corresponding to that forming 1b of the Ute limestone [Walcott, 1908f, p. 196], just south of the
south fork of Paradise Dry Canyon (locally known as Hast Fork), east of Paradise, Cees County, Utah
(L. D. Burling, 1905).
Otusia utahensis.
*Syntrophia cambria.

32f. (For stratigraphic position and association, see p. 153.) Upper Cambrian: Thin-bedded siliceous limestone
near the top of the Upper Cambrian, about 2 miles (3.2 km.) southeast of Muskrat Spring, on the northwest
face of Grantsville Peak, Stansbury Range, Tooele County, Utah (F. B. Weeks and L. D. Burling, 1905).
Lingulella manticula.
Lingulella pogonipensis.

32g. (For stratigraphic position and association, see p. 154.) Upper Cambrian: About 2,575 feet (784.9 m.) above
the Cambrian quartzitic sandstones, in a blue limestone about 2 miles (3.2 km.) southeast of Muskrat Spring,
on the northwest face of Grantsville Peak, Stansbury Range, Tooele County, Utah (L. D. Burling, 1905).
Obolus mcconnelli pelias. Lingulella isse.
Lingulella desiderata. Linnarssonella nitens. +

$2h. (For stratigraphic position and association, see p. 157.) Middle Cambrian: Shales in a canyon on the west
side of the Simpson Range, 4 miles (6.4 km.) south of Simpson Spring, about 20 miles (32.2 km.) west-south-
west of Vernon, Tooele County, Utah (F. B. Weeks and L. D. Burling, 1905).
Obolus (Westonia) ella.

32j. (For stratigraphic position and association, see p. 157.) Middle Cambrian: 625 feet (190.5 m.) above the
Cambrian quartzitic sandstones, in pinkish-colored very fine grained arenaceous shale 2 miles (3.2 km.)
southeast of Muskrat Spring, on the northwest face of Grantsville Peak, Stansbury Range, Tooele County,
Utah (L. D. Burling, 1905).
Acrotreta cf. ophirensis.

32k. (For stratigraphic position and association, see p. 156.) Middle? Cambrian: Limestones about 1,550 feet
(472.4 m.) above the top of the Cambrian quartzitic sandstones 2 miles (3.2 km.) southeast of Muskrat
Spring, on the northwest face of Grantsville Peak, Stansbury Range, Tooele County, Utah (L. D. Burling,
1905).
Obolus meconnelli.

32n. (For stratigraphic position and association, see p. 151.) Middle Cambrian: Shales about 725 feet (221 m.)
above the Brigham quartzite [Walcott, 1908a, p. 8], in the Wasatch Mountains, 1 mile (1.6 km.) northwest
of Geneva (Copenhagen), Boxelder County, Utah (L. D. Burling, 1905).
Obolus (Westonia) ella?.

320. (For stratigraphic position and association, see p. 158.) Middle Cambrian: Shale about 325 feet (99 m.)
above the Cambrian quartzitic sandstones 2 miles (3.2 km.) southeast of Muskrat Spring, on the northwest
face of Grantsville Peak, Stansbury Range, Tooele County, Utah (L. D. Burling, 1905).
Obolus (Westonia) ella.

32p (=55e). (For stratigraphic position and association, see p. 152.) (L. D. Burling, 1905.)
Obolus (Westonia) ella.
Acrothele subsidua.

32t. (For stratigraphic position and association, see p. 154.) Upper Cambrian: Limestone about 3,650 feet (1,112.5
m.) above the Cambrian quartzitic sandstones in Fandango Spring canyon, on the east side of the Dugway
Range, about 5 miles (8 km.) north of where the stage road between Vernon and Deep Creek crosses the
divide, Tooele County, Utah (L. D. Burling, 1905).
Linnarssonella girtyi.

LOCALITIES. | 195

32x (=54k faunally). (Forstratigraphic position and association, see p. 150.) Middle Cambrian: About 1,700 feet
(518.2 m.) above the Brigham quartzite [Walcott, 1908a, p. 8], in shales correlated with the shales forming
2d of the Bloomington formation in Blacksmith Fork Canyon [Walcott, 1908f, p. 195], Wasatch Canyon,
east of Lakeview ranch, 5 miles (8 km.) north of Brigham, Boxelder County, Utah (L. D. Burling, 1905).
Obolus (Westonia) wasatchensis.

82y. (For stratigraphic position and association, see p. 151.) Middle Cambrian: Shales about 175 feet (53.3 m.)
above the Brigham quartzite [Walcott, 1908a, p. 8], in the Wasatch Mountains, 1 mile (1.6 km.) northwest
of Geneva (Copenhagen), east of Brigham, Boxelder County, Utah (F. B. Weeks and L. D. Burling, 1905).
Obolus (Westonia) ella.

32z (below 32h at same locality). (Forstratigraphic position and association, see p. 157.) Middle Cambrian: Shales
in a canyon on the west side of the Simpson Range, 4 miles (6.4 km.) south of Simpson Spring, about 20 miles
(32.2 kin.) west-southwest of Vernon, Tooele County, Utah (F. B. Weeks and L. D. Burling, 1905).
Obolus (Westonia) ella.

33 (see 338c). Lower Cambrian: Limestone on the roadside near Rock Hill schoolhouse, near North Greenwich,
about 5 miles (8 km.) north-northeast of Greenwich, Cambridge quadrangle (U. S. G. S.), Washington
County, N. Y. (C. D. Walcott, 1886).

Botsfordia ceelata. Stenotheca rugosa (Hall).

Acrotreta sagittalis taconica. ‘Microdiscus lobatus (Hall).
Billingsella salemensis. Microdiscus speciosus Ford.
Archzocyathus dwighti Walcott. Elliptocephala asaphoides Emmons.
Hyolithellus micans (Billings). Zacanthoides eatoni Walcott.
Hyolithes americanus Billings. Ptychoparia cf. adamsi (Billings).
Hyolithes communis Billings. Protypus clavatus Walcott.
Hyolithes impar Ford. Solenopleura tumida Walcott.

Stenotheca elongata Walcott.

33b. Lower Cambrian: Limestone, 1.5 miles (2.4 km.) east-southeast of North Greenwich, about 5 miles (8 km.)
north-northeast of Greenwich, Cambridge quadrangle (U. 8. G. S.), Washington County, N. Y. (C. D.
Walcott, 1886).
Botsfordia ceelata.
Hyolithellus micans (Billings).
Hyolithes communis Billings.

Microdiscus lobatus (Hall).
Microdiscus speciosus Ford.
Elliptocephala asaphoides Emmons.

33d (same horizon as 15d). (For stratigraphic position and association, see p. 154.) Upper Cambrian: Thin-bedded
blue limestone at the base of the first high point southwest of the J. J. Thomas ranch, on the east side of the
Fish Spring Range, Juab County, Utah (L. D. Burling, 1905).
Obolus meconnelli pelias. Schizambon typicalis.
Obolus rotundatus. Acrotreta marjumensis.
Lingulella isse.

383i. (For stratigraphic position and association, see p. 157.) Middle Cambrian: Shales about 400 feet (122 m.) above
the Cambrian quartzitic sandstones on the western slope of the high peak southwest of Lookout Pass, Onaqui
Range, west of Vernon, Tooele County, Utah (L. D. Burling, 1905).
*Obolus (Westonia) ella onaquiensis.
Obolus (Westonia) cf. ella onaquiensis.

33i. (For stratigraphic position and association, see p. 158.) Lower Cambrian: About 100 feet (30.5 m.) above the
Prospect Mountain quartzite, in the shale of the Pioche formation [Walcott, 1908f, p. 171], 0.25 mile (0.4 km.)
below the Maxfield mine, Big Cottonwood Canyon, west front of the Wasatch Mountains southeast of Salt
Lake City, Salt Lake County, Utah (L. D. Burling, 1905).
Obolus (Westonia) ella.

33j. (For stratigraphic position and association, see p. 149.) Middle Cambrian: Shale about 2,300 feet (701 m.)
above the Brigham quartzite [Walcott, 1908, p. 8], in Wasatch Canyon, east of Lakeview ranch, 5 miles
(8 km.) north of Brigham, Boxelder County, Utah (L. D. Burling, 1905).
Obolus (Westonia) wasatchensis.

331. (For stratigraphic position and association, see p. 153.) Upper Cambrian: Limestones in pass between the
Pavant Mountains and the Canyon Range, a few hundred yards east of the divide, on the road between
Holden and Scipio, Millard County, Utah (L. D. Burling, 1905).
Eoorthis desmopleura.
Solenopleura.
Illenurus.

196 CAMBRIAN BRACHIOPODA.

33n. (For stratigraphic position and association, see p. 154.) Middle? Cambrian: Limestone pebbles, west front
of the Pavant Mountains, collected in the wash at the mouth of Crow Creek, about 4 miles (6.4 km.) east
of Fillmore, Millard County, Utah (L. D. Burling, 1905).
Acrotreta idahoensis alta.

38r. (For stratigraphic position and association, see p. 157.) Middle Cambrian: Limestones faulted against the
Cambrian quartzites in a canyon about 1 mile (1.6 km.) east of Cricket Spring, Cricket Range (locally known
as the Beaver River Range or the Beaver Mountains), northwest of Black Rock. Millard County, Utah (L. D.
Burling, 1905).
*Otusia utahensis.

33t. (For stratigraphic position and association, see p. 150.) Middle Cambrian: Shale about 1,500 feet (457.2 m.)
above the Brigham quartzite [Walcott, 1908a, p. 8], 1 mile (1.6 km.) northwest of Geneva (Copenhagen),
east of Brigham, Boxelder County, Utah (F. B. Weeks, 1905).
Obolus (Westonia) wasatchensis.

34. Lower Cambrian: Limestone on roadside a little west of the bridge over Poultney River at Low Hampton,
about 5 miles (8 km.) east-northeast of Whitehall, Whitehall quadrangle (U.S. G. S.), Washington County,
N. Y. (C. D. Walcott, 1886).

Micromitra (Iphidella) pannula. Microdiscus lobatus (Hall).
Lingulella granvillensis. Microdiscus speciosus Ford.
Botsfordia celata. Elliptocephala asaphoides Emmons.
Acrotreta sagittalis taconica. Ptychoparia cf. adamsi (Billings).
Platyceras primevum Billings. Ptychoparia fitchi Walcott.
Hyolithes communis Billings. Solenopleura tumida Walcott.
Microdiscus connexus Walcott. Zacauthoides eatoni Walcott.

34a. Lower Cambrian: Limestones 1 mile (1.6 km.) west of North Hebron, 5 miles (8 km.) south-southwest of
Granville, Fort Ann quadrangle (U. S. G. S.), Washington County, N. Y. (C. D. Walcott, 1886).
Botsfordia ceelata.
Microdiscus lobatus (Hall).
Microdiscus speciosus Ford.

34g. (For stratigraphic position and association, see p. 153.) Passage beds between the Cambrian and Ordovician:

Limestones about 1,000 feet (305 m.) above the valley on the east side of the Fish Spring Range, just west of —

the high point southwest of the J. J. Thomas ranch, Juab County, Utah (L. D. Burling, 1905).
EKoorthis desmopleura.

34i. (For stratigraphic position and association, see p. 154.) Upper Cambrian: Shales about 1 mile (1.6 km.)
northeast of Sand Pass, at the south end of the Fish Spring Range, Juab County, Utah (C. D. Walcott and
_L. D. Burling, 1905).
Obolus rotundatus.
Lingulella desiderata.
Lingulella isse.

34m. (For stratigraphic position and association, see p. 151.) Middle Cambrian: Limestone about 765 feet (233.2
m.) above the Brigham quartzite [Walcott, 1908a, p. 8], 1 mile (1.6 km.) northwest of Geneva (Copenhagen),
east of Brigham, Boxelder County, Utah (L. D. Burling, 1905).
Micromitra (Paterina) labradorica utahensis.
Syntrophia cambria.

34n. (For stratigraphic position and association, see p. 158.) Middle Cambrian: Shaies about 100 feet (30.5 m.)
above the Tintic quartzite [G. O. Smith, 1900, p. 1], near the summit of the ridge between Mammoth and
Eureka, Tintic special quadrangle (U. S. G. S.), Juab County, Utah (F. B. Weeks, 1905).
Obolus meconnelli.
Obolus rotundatus.

34q. (Forstratigraphic position and association, see p. 149.) Upper Cambrian: Shalesabout 3,800 feet (1,158.2 m. )
above the Brigham quartzite [Walcott, 1908a, p. 8], in Wasatch Canyon, east of akerien Ranch, about 5
miles (8 km.) north of Brigham, Boxelder County, Utah (L. D. Burling, 1905).
Obolus mcconnelli pelias.
Acrotreta idahoensis alta.

34r. (For stratigraphic position and association, see p. 154.) Upper Cambrian: Limestones 1.5 miles (2.4 km.)
northwest of Wahwah Spring, about halfway up the section to the north of the road at Cane Pass, Wahwah
Mountains, Beaver County, Utah (F. B. Weeks, 1905).
Obolus rotundatus.
Lingulella isse.

Mn

ee

- LOCALITIES. 197

34s. (For stratigraphic position and association, see p. 156.) Middle Cambrian: About 1,700 feet (018 m.) above
the Tintic quartzite, in the Mammoth limestone of G. O. Smith [1900, p. 1, and historical geology sheet],
in the saddle above and a little east of the Centennial Eureka mine, near the summit of the ridge between
Mammoth and Eureka, Tintic special quadrangle (U.S. G. S.), Juab County, Utah (F. B. Weeks, 1905).
Obolus mcconnelli.

34t. (For stratigraphic position and association, see p. 154.) Upper Cambrian: Limestone 1.5 miles (2.4 km.)
northwest of Wahwah Springs, about 80 feet (24.4 m. ) below the highest point on the north side of the road
at Cane Pass, Wahwah Mountains, Beaver County, Utah (F. B. Weeks, 1905).
Lingulella desiderata.
Lingulella isse.

34u. (For stratigraphic position and association, see p. 157.) Middle Cambrian: Shales about 950 feet (289.6 m.)
above the Cambrian quartzitic sandstones 2 miles (3.2 km.) southeast of Muskrat Spring, on the northwest
face of Grantsville Peak, Stansbury Range, Tooele County, Utah (L. D. Burling, 1905).
Obolus (Westonia) wasatchensis.

34v. (For stratigraphic position and association, see p. 155.) Middle? Cambrian: Limestone about 1,750 feet
(533 m.) above the Cambrian quartzitic sandstones about 2 miles (3.2 km.) southeast of Muskrat Spring,
on the northwest face of Grantsville Peak, Stansbury Range, Tooele County, Utah (L. D. Burling, 1905).
Obolus mcconnelli pelias. . aN

35. Lower Cambrian: Limestones 1.5 miles (2.4 km.) north of Bald Mountain and 3.5 miles (5.6 km.) north-
northwest of Greenwich, Schuylerville quadrangle (U.S. G. S.), Washington County, N. Y. (C. D. Walcott,

1886).

Obolus prindlei. Platyceras primevum Billings.
Lingulella granvillensis. Hyolithellus micans (Billings).
Obolella crassa. Hyolithellus micans rugosa Walcott.
Botsfordia celata. Hyolithes communis Billings.
Acrotreta sagittalis taconica. Elliptocephala asaphoides Emmons.
Stenotheca rugosa (Hall). : Solenopleura tumida Walcott.

35a. Lower Cambrian: Shaly limestone on the west slope of the summit of Bald Mountain, 3 miles (4.8 km.)
north-northwest of Greenwich, Schuylerville quadrangle (U. S. G. S.), Washington County, N. Y. (C. D.
Walcott, 1886).
Botsfordia czelata.
*Acrotreta emmonsi.
Olenellus sp.

~35c. (For stratigraphic position and association, see p. 130.) Lower Cambrian: Drift blocks of siliceous shale
supposed to have come from the Mount Whyte formation [Walcott, 1908f, p. 214], found on the south slope
of Mount Bosworth, about 500 feet (152 m.) northwest of the Canadian Pacific Railway track between Stephen
and Hector, eastern British Columbia, Canada (Mr. and Mrs. C. D. Walcott and Mr. and Mrs. L. D. Burling,

1907).
*Micromitra (Paterina) wapta. *Albertella bosworthi Walcott.
*Obolus parvus. *Albertella helena Walcott.
Acrothele colleni. Bathyuriscus.
Wimanella simplex. Agraulos.
Hyolithellus. 5 Ptychoparia.
Hyolithes. Bathyuriscus.

85d. (Forstratigraphic position and association, see p. 130.) Lower Cambrian: About 3,150 feet (960.1 m.) below
the Middle Cambrian, in the siliceous Lake Louise shale [Walcott, 1908f, p. 216], in cliff on the north side
of Lake Louise, at its upper end, southeast of Laggan, on the Canadian Pacific Railway, Alberta, Canada
(Mr. and Mrs. C. D. Walcott and Mr. and Mrs. L. D. Burling, 1907).
*Micromitra (Iphidella) louise.
Cruziana.
Annelid trails.

85e. (For stratigraphic position and association, see p. 130.) Lower Cambrian: About 270 feet (82.3 m.) below
the Middle Cambrian, in a greenish siliceous shale correlated with No. 3 of the Mount Whyte formation on
Mount Bosworth [Walcott, 1908f, p. 214], in the amphitheater between Popes Peak and Mount Whyte, about
3 miles (4.8 km.) northwest of Lake Louise, southwest of Laggan on the Canadian Pacific Railway, Alberta,
Canada (C. D. Walcott and L. D. Burling, 1907).

Micromitra (Paterina) wapta. Ptychoparia sp.

Obolus parvus. Albertella sp.

Acrothele colleni. Bathyuriscus.

Hyolithes billingsi Walcott. Olenellus gilberti (Meek).

Olenopsis.

198 CAMBRIAN BRACHIOPODA.

35f. (For stratigraphic position and association, see p. 130.) Lower Cambrian: About 300 feet (91 m.) below the
Middle Cambrian, in the limestone forming 6 of the Mount Whyte formation [Walcott, 1908c, p. 242 (11)],
just above the tunnel on the north shoulder of Mount Stephen, about 3 miles (4.8 km.) east of Field, British
Columbia, Canada (C. D. Walcott and L. D. Burling, 1907).

Micromitra (Iphidella) pannula var. Scenella varians Walcott. d
Kutorgina cingulata. Ptychoparia 3 sp.

Kutorgina?. Agraulos sp.

Acrotreta sagittalis taconica. Protypus sp.

Nisusia festinata. Olenellus canadensis Walcott.

Hyolithes billingsi Walcott. Olenellus gilberti (Meek).

35g. (Forstratigraphic position and association, see p. 126.) Middle Cambrian: About 4,100 feet (1,250 m.) above
the Lower Cambrian and 860 feet (262 m.) below the Upper Cambrian, in the shaly limestones in 2 of the
Eldon limestone [Walcott, 19081, p. 209], at the north end of the amphitheater northwest of the main ridge
of Mount Bosworth, north of the Canadian Pacific Railway between Hector and Stephen, on the Continental
Divide between British Columbia and Alberta, Canada (C. D. Walcott and L. D. Burling, 1907).
Obolus meconnelli var. Isoxys cf. argentea (Walcott).
*Obolus membranaceus. i Ptychoparia 3 sp. j

35h. (For stratigraphic position and association, see p. 130.) Lower Cambrian: About 375 feet (114 m.) below the
Middle Cambrian, in the shales of No. 4 of the Mount Whyte formation [Walcott, 1908f, p. 214], on Mount
Bosworth, north of the Canadian Pacific Railway between Hector and Stephen, on the Continental Divide
between British Columbia and Alberta, Canada (Mr. and Mrs. C. D. Walcott, Mr. and Mrs. L. D. Burling,
and Helen and Stuart Walcott).

Nisusia festinata. Agraulos.

Scenella varians Walcott. Olenellus canadensis Walcott.
Hyolithellus. Olenellus gilberti (Meek).
Ptychoparia.

35k. (For stratigraphic position and association, see p. 127.) Middle Cambrian: Burgess shale member of the
Stephen formation on the west slope of the ridge between Mount Field and Wapta Peak, 1 mile (1.6 km.)
northeast of Burgess Pass, above Field, British Columbia (Mr. and Mrs. C. D. Walcott and Stuart Walcott,
1909 and 1910.)
*Micromitra zenobia. Micromitra (Iphidella) pannula.
*Micromitra (Paterina) stissingensis ora. Nisusia alberta.

36 (see 338d). Lower Cambrian: Limestone 1 mile (1.6 km.) south of Shushan and 3.5 miles (5.6 km.) north-
northeast of Cambridge, Cambridge quadrangle (U.S. G. S.), Washington County, N. Y. (C. D. Walcott,

1886).
Acrotreta sagittalis taconica. Hyolithes communis Billings.
Nisusia festinata. Microdiscus speciosus Ford.
* Billingsella salemensis. Elliptocephala asaphoides Emmons.
Hyolithellus micans (Billings). Solenopleura tumida Walcott.

36b. Lower Cambrian: Limestone near schoolhouse No. 12, near Greenwich, Cambridge quadrangle (U.S. G.S8.),
Washington County, N. Y. (O. C. Tefft, 1887).

Obolus prindlei. Hyolithellus micans (Billings).
Botsfordia ceelata. Microdiscus lobatus (Hall).
Acrotreta sagittalis taconica. Microdiscus sp.

“37. Lower Cambrian: Limestone 1.5 miles (2.4 km.) south of Salem, Cambridge quadrangle (U.S.G.S.), Washing-
ton County, N. Y. (C. D. Walcott, 1886).
Billingsella salemensis.

37b. Lower Cambrian: Limestone 0.25 mile (0.4 km.) east of Salem, Cambridge quadrangle (U.S.G.S.), Wash-
ington County, N. Y. (C. D. Walcott, 1893).
Lingulella granvillensis.
*Yorkia washingtonensis.
Acrotreta sagittalis taconica.

Olenellus?.
Microdiscus connexus Walcott.

38. Lower Cambrian: Limestone 0.25 mile (0.4 km.) north of John Hulett’s farmhouse, about 3 miles (4.8 km.) west
of South Granville, and 4.5 miles (7.2 km.) southwest of Granville, Fort Ann quadrangle (U.S. G.8.),
Washington County, N. Y. (C. D. Walcott, 1886).
Lingulella granvillensis.
Botsfordia ceelata.
Stenotheca elongata Walcott.

Hyolithes impar Ford.
Elliptocephala asaphoides Emmons.

a This is the locality containing the beautifully preserved annelids, medusz, eurypterids, holothurians, crustaceans, etc., now being described
and illustrated in volume 57 of the Smithsonian Miscellaneous Collections.

a

Se ee eS

LOCALITIES. 199

88a. Lower Cambrian: Limestone 2 miles (3.2 km.) south of North Granville, on the road which turns south from
the road running between that village and Truthville, 4 miles (6.4 km.) west-northwest of Granville, Fort
Ann quadrangle (U. 8. G. S.), Washington County, N. Y. (C. D. Walcott, 1886).

Micromitra (Iphidella) pannula. Hyolithes americanus Billings
Obolus prindlei. Hyolithes impar Ford.
*Lingulella granvillensis. Agnostus sp.

Lingulella sp. Microdiscus connexus Walcott.
Botsfordia czelata. Microdiscus lobatus (Hall).
Yorkia? washingtonensis. Microdiscus speciosus Ford.
Acrotreta emmonsi. Elliptocephala asaphoides Emmons.
*Acrotreta sagittalis taconica Ptychoparia cf. adamsi (Billings).
Nisusia festinata. Ptychoparia fitchi Walcctt.
Protospongia sp. Ptychoparia sp.

Platyceras primzvum Billings Protypus clavatus Walcott.
Hyolithellus micans (Billings). Zacanthoides eatoni Walcott.
Hyolithellus micans rugosa Walcott. Olenoides fordi Walcott.

ce. Lower Cambrian: Shale at the slate quarries on the west side of the valley 1 mile (1.6 km.) north of Middle
Granville, Mettawee quadrangle (U.S. G. S.), Washington County, N. Y. (C. D. Walcott, 1886).
Botsfordia ceelata.

39. Lower Cambrian: Limestone south of the Delaware and Hudson Railroad track, on the road running south-
southwest from Low Hampton, about 5 miles (8 km.) east-northeast of Whitehall, Whitehall GREE
(U.S. G. 8.), Washington County, N. Y. (C. D. Walcott, 1886).
Botsfordia czelata. Microdiscus speciosus Ford.
Acrotreta sagittalis taconica. Protypus clavatus Walcott.
Archeeocyathus dwighti Walcott.

39a. Lower Cambrian: Limestone 0.25 mile (0.4 km.) north of Easton Station, 3 miles (4.8 km.) south of Green-
_ wich, Cambridge quadrangle (U.S. G. S.), Washington County, N. Y. (C. D. Walcott, 1887).
Botsfordia czelata.
Hyolithellus micans rugosa Walcott.
Microdiscus lobatus (Hall).

41 (same horizon as 51). (For stratigraphic position and association, see p. 141.) Lower Cambrian: Sandstone [see
Walcott, 1891b, p. 260, for position in section] on Manuels Brook, Conception Bay, Newfoundland (C. D.
Walcott, 1888).

*Obolella atlantica. Coleoloides typicalis Walcott.
Hyolithellus micans (Billings). Microdiscus bellimarginatus Shaler and Foerste.
Helenia bella Walcott. Microdiscus helena Walcott.
Hyolithes princeps Billings. Callavia bréggeri (Walcott).
Hyolithes quadricostatus Shaler and Foerste. Ptychoparia attleborensis Shaler and Foerste.
Hyolithes similis Walcott. Ptychoparia sp.
Hyolithes sp. Solenopleura bombifrons Matthew.
Stenotheca rugosa (Hall). Solenopleura howleyi Walcott.
Stenotheca rugosa acuticosta Walcott. Avalonia manuelensis Walcott.
Stenotheca rugosa erecta Walcott. Agraulos strenuus Billings.
Stenotheca rogosa leevis Walcott. Agraulos strenuus nasutus Walcott.
Stenotheca rugosa pauper Billings. Agraulos sp.
Walcott [1891b, p. 260] cites the following additional species:
Hyolithes impar Ford. Platyceras primezevum Billings.
Hyolithes terranovicus Walcott. Microdiscus speciosus Ford.

Scenella reticulata Billings.

41a. (For stratigraphic position and association, see p. 141.) Lower Cambrian: Limestone [see Walcott, 1891b,
p- 260] on the mainland beneath Topsail Head, Conception Bay, Newfoundland.

Micromitra (Paterina) labradorica. Hyolithes princeps Billings.

Obolella atlantica. Microdiscus bellimarginatus Shaler and Foerste.
Scenella reticulata Billings. Ptychoparia attleborensis Shaler and Foerste.
Hyolithellus micans (Billings). Avyalonia manuelensis Walcott.

Hyolithellus micans rugosa Walcott. Agraulos strenuus Billings.

Hyolithes impar var.
Walcott [1891b, p. 260] cites the following additional species:

Microdiscus speciosus Ford. Solenopleura bombifrons Matthew.

Microdiscus sp. undt. Agraulos sp.

Callavia bréggeri (Walcott).

200 CAMBRIAN BRACHIOPODA.

43. Ordovician: Shales on the summit of Moses Hill,

2 miles (3.2 km.) west of North Greenwich, near the line

between the Schuylerville and Cambridge quadrangles (U.S. G.S.), Washington County, N. Y. (C. D. Wal-

cott, 1887).
Acrothele pretiosa.

43a. Lower Cambrian: Limestone 1 mile (1.6 km.) east-northeast of Salem, Cambridge quadrangle (U.S. G.S.),
Washington County, N. Y. (C. D. Walcott and W. P. Rust, 1887).

Botsfordia czelata.

Acrotreta sagittalis taconica.
Protospongia sp.

Hyolithes impar Ford.
Microdiscus connexus Walcott.
Microdiscus lobatus (Hall).

Microdiscus speciosus Ford.
Agnostus desideratus Walcott.
Ptychoparia cf. adamsi (Billings).
Protypus clavatus Walcott.
Zacanthoides eatoni Walcott.

44a (a little north of 446). Lower Cambrian: Limestone on Valatie Kill, near the line between Nassau and Scho-
dack townships, near line between Troy and Kinderhook quadrangles (U. S. G.S.), Rensselaer County,

N. Y. (C. D. Walcott, 1887).
Acrotreta sagittalis taconica.
Microdiscus connexus Walcott.

44b (a little south of 44a). Lower Cambrian: Limestone near North Chatham, in the northern part of the Kinder-
hook quadrangle (U. 8. G. 8.), Columbia County, N. Y. (C. D. Walcott, 1887).

Micromitra (Iphidella) pannula.
Lingulella granvillensis.
Acrotreta sagittalis taconica.

Hyolithellus micans (Billings).
Agnostus sp.

45a. Lower Cambrian: Limestone at McNaughton Corner, 1 mile (1.6 km.) east of Salem, Cambridge quadrangle
(U. 8. G. S.), Washington County, N. Y. (Ira Sayles, 1887).

Acrotreta sagittalis taconica.
Archeocyathus dwighti Walcott.
Archeeocyathus rarus (Ford).
Hyolithellus micans (Billings).

Microdiscus lobatus (Hall).
Microdiscus speciosus Ford.
Solenopleura tumida Walcott.
Zacanthoides eatoni Walcott.

45b. Lower Cambrian: Limestone near the roadside about 1,200 feet (366 m.) east of Bristol’s house, near Low
Hampton, about 5 miles (8 km.) east-northeast of Whitehall, Whitehall quadrangle (U. S. G. S.), Wash-

ington County, N. Y. (Ira Sayles, 1887).
Obolus prindlei.
Acrotreta sagittalis taconica.
Platyceras primzevum Billings.
Hyolithellus micans (Billings).
Hyolithes americanus Billings.

Hyolithes impar Ford.

Microdiscus speciosus Ford.
Elliptocephala asaphoides Emmons.
Solenopleura tumida Walcott.

47a. Lower Cambrian: Sandstone on the southwest side of Sallings Mountain, 2 miles (3.2 km.) east of Natural

Bridge, Rockbridge County, Va. (C. D. Walcott,

*Kutorgina sp. undt.

Obolella minor.

1891).
Hyolithes communis Billings.
Olenellus sp.

47c. Lower Cambrian: Sandstone 2 miles (3.2 km.) west of bridge at Harpers Ferry, Jefferson County, W. Va.

(C. D. Walcott, 1892).
Obolella minor.
Olenellus thompsoni (Hall).

47d (see 16f). Lower Cambrian: Sandstones 1 mile (1.6 km.) east-southeast of Smithsburg, Washington County,

Md. (C. D. Walcott, 1892*
Obolella minor?.
Olenellus thompsoni (Hall).

Ave (see 16f). Lower Cambrian: Sandstone on Observatory Hill, 2 miles (3.2 km.) south of See Wash-

ington County, Md. (C. D. Walcott, 1892).
Obolella minor.
Olenellus thompsoni (Bla).

47f (see 16f). Lower Cambrian: Sandstone at Eakles Mills, 2

County, Md. (C. D. Walcott, 1892).
Obolella minor.
Olenellus thompsoni (Hall).

miles (3.2 km.) south of Keedysville, Washington

|
.
:

LOCALITIES. 201

47h. Middle Cambrian: Shales on Wolf Creek, 6 miles (9.6 km.) below Rocky Gap, Bland County, Va. (M. R.
Campbell, 1893).
Dicellomus appalachia.

48d. Middle Cambrian: Argillaceous shales in railroad cut alongside of gas house, city of York, York County, Pa.
(H. E. Dickhaut, 1901).
*Lingulella sp. undt. b.
*Acrothele yorkensis.

49. Lower Cambrian: Sandstone on Codorus Creek 0.125 mile (0.2 km.) below Meyer’s mill, near Emigsville, York
County, Pa. (Charles Schuchert, 1893).
Rustella edsoni?.
Micromitra (Paterina) bella.
*Yorkia wanneri.

Nisusia festinata.
Olenellus thompsoni crassimarginatus Walcott.

49a. lower Cambrian: Sandstone on the Liverpool road, south of the schoolhouse, 3 miles (4.8 km.) northwest of
York, York County, Pa. (Charles Schuchert, 1893).
Rustella edsoni. Nisusia festinata.
Yorkia wanneri. : Olenellus thompsoni crassimarginatus Walcott.

49b. Lower Cambrian: Sandstone in the continuation of the ridge mentioned in Locality 49c, 2 miles (3.2 km.)
northwest of Emigsville, York County, Pa. (C. D. Walcott, 1892).
Obolella minor.
Olenellus thompsoni (Hall).

49c. Lower Cambrian: Sandstone in ridge just north of the railway station at Emigsville, York County, Pa.
(C. D. Walcott, 1892).
Obolella minor.
Olenellus thompsoni (Hall).

49d. Lower Cambrian: Sandstone 3 miles (4.8 km.) east of Waynesboro, Franklin County, Pa. (C. D. Walcott,
1892).
Obolella minor.
Olenellus thompsoni (Hall).

49e. Lower Cambrian: Sandstone 1 mile (1.6 km.) south of Mount Zion Church and 4 miles (6.4 km.) northeast
of York, York County, Pa. (C. D. Walcott, 1892).
Obolella minor.
Olenellus thompsoni (Hall).

49f. Lower Cambrian: Sandstones of Mount Holly Gap, South Mountain, Cumberland County, Pa. (C. D. Wal-
cott, 1892). : ;

Obolella minor?.

Hyolithes sp.

Olenellus? sp.

49w. Lower Cambrian: Limestone in railroad cut 0.25 mile (0.4 km.) south of Emigsville, York County, Pa. (C. D.
Walcott, 1892).
Micromitra (Paterina) bella.
Nisusia festinata.

50. Lower Cambrian: Shaly limestones 1.125 miles (1.8 km.) north of Stoner, 10 miles (16.1 km.) east-northeast
of York, York County, Pa. (C. D. Walcott, 1892).
*Acrothele decipiens.
Olenellus.

50a. Lower Cambrian: Sandstone 2 miles (3.2 km.) northwest of York, York County, Pa. (C. D. Walcott, 1892).
Obolella crassa?.
Olenellus sp.

52. (For stratigraphic position and association, see p. 140.) Lower Cambrian: Arenaceous shales just above the
Prospect Mountain quartzite, in a stratigraphic position similar to that of the Pioche formation [Walcott,
1908f, p. 184], at the top of Prospect Mountain, Eureka district [Hague, 1892, Atlas], Eureka County, Nev.
(J. P. Iddings and C. D. Walcott, 1880).

*Micromitra (Paterina) prospectensis. Olenellus fremonti Walcott.
Girvanella sp. Peachella iddingsi (Walcott).
Scenella? conula Walcott. Dorypyge ? quadriceps (Hall and Whitfield).

Callavia nevadensis Walcott.

202 CAMBRIAN BRACHIOPODA.

53 (below 178a). (For stratisraphic position and association, seep. 138.) Lower Cambrian: Sandstones in the lower
portion of 3d of the Waucoba Springs section [ Walcott, 1908f, pp. 187 and 188], 1 mile(1.6km.) east of Saline
Valley road, about 2.5 miles (4 km.) east-northeast of Waucoba Springs, Inyo County, Cal. (C. D. Walcott,

1897).
Mickwitzia occidens. Ethmophyllum gracile Meek.
Obolella vermilionensis. Hyolithes sp.
*Trematobolus excelsis. Wanneria gracile Walcott.
Archzeocyathus. ; .

53a. (For stratigraphic position and association, see p. 138.)
Obolella sp.

54. (For stratigraphic position and association, seep. 140.) Middle Cambrian: Eldorado limestone [Walcott, 1908f,
p. 184] on east slope of Prospect Mountain, in New York Canyon, Eureka district [Hague, 1892, Atlas],
Eureka County, Ney. (C. D. Walcott, 1886).
Lingulella arguta. ;
Lingulella punctata.

54a (=3le). (For stratigraphic position and association, see p. 151.) (C. D. Walcott and L. D. Burling, 1906.)
Micromitra (Paterina) labradorica utahensis. Isoxys cf. argentea (Walcott).
Obolus (Westonia) ella. Ptychoparia.
Acrothele turneri?.

54b. (Forstratigraphic position and association, see p. 148.) Upper Cambrian: About 1,200 feet (365.8 m.) above
the Middle Cambrian and 25 feet (7.6 m.) below the top of the Upper Cambrian, in the upper part of the
limestone forming 1 of the St. Charles limestone [Walcott, 1908f, p. 191], in Blacksmith Fork Canyon, about
10 miles (16.1 km.) east of Hyrum, Cache County, Utah (C. D. Walcott and L. D. Burling, 1906).
Lingulella manticula. Syntrophia nundina.
Eoorthis desmopleura. Dikellocephalus.

54c. (For stratigraphic position and association, see p. 148.) Upper Cambrian: About 1,100 feet (335.3 m.) above
the Middle Cambrian and 120 feet (36.6 m.) below the top of the Upper Cambrian, in the central part of the
limestone forming 1 of the St. Charles limestone [Walcott, 1908f, p. 192], in Blacksmith Fork Canyon, about
10 miles (16.1 km.) east of Hyrum, Cache County, Utah (C. D. Walcott and L. D. Burling, 1906).

Schizambon typicalis. Solenopleura.
EKoorthis desmopleura. Menocephalus.
*Koorthis newberryi. Ileenurus.

Syntrophia nundina.

54d. (For stratigraphic position and association, see p. 148.) Upper Cambrian: About 1,050 feet (320 m.) above the
Middle Cambrian and 175 feet (53.3 m.) below the top of the Upper Cambrian, in the lower part of the lime-
stone forming 1 of the St. Charles limestone [Walcott, 1908f, p. 192], in Blacksmith Fork Canyon, about 10
miles (16.1 km.) east of Hyrum, Cache County, Utah (C. D. Walcott and L. D. Burling, 1906).

Lingulella (Lingulepis) acuminata. Menocephalus.
Eoorthis desmopleura. Solenopleura.
Eoorthis newberryi. Asaphus?.
Aegnostus.

54e. (For stratigraphic position and association, see p. 149.) Upper Cambrian: About 200 feet (61 m.) above the
Middle Cambrian and 1,025 feet (212.4 m.) below the top of the Upper Cambrian, in limestones forming 3 of
the St. Charles limestone [Walcott, 1908f, p. 193], in Blacksmith Fork Canyon, about 10 miles (16.1 km.) east
of Hyrum, Cache County, Utah (Mrs. ©. D. Walcott, Stuart Walcott, and L. D. Burling, 1906).

Obolus discoideus. Hyolithes.
Obolus (Westonia) ella. Cyrtolites.
Lingulella manticula. Agnostus.
Billingsella coloradoensis. Ptychoparia.
*Huenella lesleyi. Anomocare.

54f. (For stratigraphic position and association, seep. 149.) Upper Cambrian: 150 feet (45.7m.) above the Middle
Cambrian and 1,075 feet (327.7 m.) below the top of the Upper Cambrian, in the light-gray sandstone forming
4 of the St. Charles limestone [Walcott, 1908f, p. 193], in Blacksmith Fork Canyon, about 10 miles(16.1 km.)
east of Hyrum, Cache County, Utah (C. D. Walcott and L. D. Burling, 1906).
Obolus discoideus. Acrotreta idahoensis alta.
Obolus (Fordinia) bellulus?. Billingsella coloradoensis.

-

LOCALITIES. 203

54g. (For stratigraphic position and association, see p. 149.) Upper Cambrian: Just above the Middle Cambrian,
near the base of the bedded light-gray sandstone forming 4 of the St. Charles limestone [Walcott, 1908f,
p. 193], in Blacksmith Fork Canyon, about 10 miles (16.1 km.) east of Hyrum, Cache County, Utah (C. D.
Walcott and L. D. Burling, 1906).
Lingulella (Lingulepis) acuminata.

54h (=311). (For stratigraphic position and association, see p. 149.) (L. D. Burling and Stuart Walcott, 1906.)

Protospongia. Hyolithes.
Obolus mcconnelli pelias. Agnostus.
Obolus (Westonia) wasatchensis. d Ptychoparia.

Lingulella desiderata.

54i(=31k). (Forstratigraphic position and association, see p. 150.) Middle Cambrian: About 2,950 feet (899.2 m.)
above the Brigham quartzite and 1,225 feet (373.4 m.) below the Upper Cambrian, in the limestone forming le
of the Bloomington formation [Walcott, 1908f, p. 194], in Blacksmith Fork Canyon, about 10 miles (16.1 km.)
east of Hyrum, Cache County, Utah (L. D. Burling, 1905).

Micromitra cf. sculptilis. Agraulos.
Hyolithes. Ptychoparia.

54j. (For stratigraphic position and association, see p. 148.) Upper Cambrian: About 700 feet (213.4m.) above the
Middle Cambrian and 525 feet (160 m.) below the top of the Upper Cambrian, in the arenaceous limestones
forming 2c of the St. Charles limestone [Walcott, 1908f, p. 192], in Blacksmith Fork Canyon, about 10 miles
(16.1 km.) east of Hyrum, Cache County, Utah (C. D. Walcott, Stuart Walcott, and L. D. Burling, 1906).
Obolus (Westonia) iphis.
Lingulella desiderata.

54k. (Forstratigraphic position and association, seep. 150.) Middle Cambrian: About 2,100feet (640m.) above the
Lower Cambrian and 2,100 feet (640 m.) below the Upper Cambrian, in the shales forming 2d of the Bloom-
ington formation [Walcott, 1908f, p. 195], in Blacksmith Fork Canyon, about 10 miles (16.1 km.) east of
Hyrum, Cache County, Utah (C. D. Walcott and L. D. Burling, 1906).
Obolus (Westonia) wasatchensis.

Agraulos.
Ptychoparia.
541(=38l1d). (For stratigraphic position and association, see p. 152.) (C. D. Walcott, 1906.)
Micromitra (Iphidella) pannula. Orthotheca major Walcott.
Obolus (Westonia) ella?. Leperditia.
Lingulella desiderata. Ptychoparia.
Hyolithes. Bathyuriscus productus (Hall and Whitfield).

54m (=31f). (Forstratigraphic position and association, see p. 150.) Middle Cambrian: About 1,225 feet (373.4 m.)
y above the Brigham quartzite and 2,950 feet (899.2 m.) below the Upper Cambrian, in the upper part of the
limestone forming la of the Ute limestone [Walcott, 1908£, p. 195], in Blacksmith Fork Canyon, about 10

miles (16.1 km.) east of Hyrum, Cache County, Utah (C. D. Walcott and L. D. Burling, 1906).

*Micromitra (Paterina) labradorica utahensis. Ptychoparia subcoronata (Hall and Whitfield).
Billingsella sp. Dorypyge? quadriceps (Hall and Whitfield).
Hyolithes.

64n. (Forstratigraphic position and association, seep. 151.) Middle Cambrian: About 550 feet (167.6 m.) above the
Brigham quartzite and 3,640 feet (1,109.5 m.) below the Upper Cambrian, in the limestone forming 2e of the
Ute limestone [Walcott, 1908f, p. 197], in Blacksmith Fork Canyon, about 10 miles (16.1 km.) east of Hyrum,
Cache County, Utah (C. D. Walcott, 1906).

*Micromitra (Paterina) stuarti. Dorypyge (fragment).
Micromitra (Paterina) superba. Ptychoparia.
Hyolithes.
540(=3lc). (For stratigraphic position and association, see p. 151.) (C. D. Walcott and L. D. Burling, 1906.)
Micromitra (Paterina) labradorica utahensis. Hyolithes.
Billingsella coloradoensis. Scenella.
*Koorthis zeno. Ptychoparia subcoronata (Hall and Whitfield.)
Syntrophia cambria. Dorypyge? quadriceps (Hall and Whitfield.)

54p. (For stratigraphic position and association, see p. 151.) Middle Cambrian: About 525 feet (160 m.) above
the Brigham quartzite and 3,665 feet (1,127.1 m.) below the Upper Cambrian, in the shales forming 2f of
the Ute limestone [Walcott, 1908f, p. 197], in Blacksmith Fork Canyon, about 10 miles (16.1 km.) east of
Hyrum, Cache County, Utah (C. D. Walcott and L. D. Burling, 1906).
Micromitra (Paterina) superba.
Obolus mcconnelli.
Ptychoparia sp. undt.

204 CAMBRIAN BRACHIOPODA.

64q (same horizon as 32x). (For stratigraphic position and association, see p. 150.) Middle Cambrian: A drift
block supposed to have come from a horizon 1,700 feet (518.2 m.) above the Bricham quartzite [Walcott,
1908a, p. 8], found near the mouth of Wasatch Canyon, east of Lakeview ranch, 5 miles (8 km.) north of
Brigham, Boxelder County, Utah (C. D. Walcott, 1906).

Micromitra (Iphidella) pannula?.
Obolus sp. undt.
*Obolus (Westonia) wasatchensis.

Acrothele subsidua.
Nisusia alberta.
Nisusia alberta?.

54r. (For stratigraphic position and association, see p. 148.) Upper Cambrian: Drift pieces of limestone from the
west slope of the Wasatch Range, east of Lakeview ranch, about 5 miles (8 km.) north of Brigham, Box-
elder County, Utah (C. D. Walcott and L. D. Burling, 1906).

Obolus meconnelli pelias.
-Eoorthis desmopleura.

54s (=5b). (For stratigraphic position and association, see p. 152.) Middle Cambrian: Dark blue-gray Langston
limestone [Walcott, 1908f, p. 198], just above the Cambrian quartzitic sandstones, north side of Twomile
Canyon, near its mouth, 2 miles (3.2 km.) southeast of Malade, Oneida County, Idaho (C. D. Walcott and

L. D. Burling, 1906).
*Micromitra haydeni (54s).
Micromitra (Iphidella) pannula.
*Micromitra (Iphidella) pannula maladensis (5b).
Micromitra (Iphidella) pannula ophirensis.
Lingulella desiderata.
Lingulella helena.
Lingulella isse.
*Acrothele artemis (5b).
Acrothele subsidua.
Acrothele subsidua var.
Acrotreta idahoensis sulcata.
Acrotreta pyxidicula.
Acrotreta?. ;
*Acrothyra minor (5b).

Billingsella coloradoensis..

Hyolithes.
Orthotheca.
Stenotheca.
Platyceras.
Agnostus.
Microdiscus.
Solenopleura.
Ptychoparia 2 sp.
Oryctocephalus.
Dorypyge 2 sp.
Neolenus 2 sp.
Asaphiscus.
Ogygopsis?.

b4t (=4y, 5a, 5c, 5e, and 54w). (For stratigraphic position and association, see p. 149.) Upper Cambrian: Lime-
stone of the St. Charles limestone [Walcott, 1908a, p. 6], about 250 feet (76 m.) above the Middle Cambrian,
on the north side of Twomile Canyon, near its mouth, 2 miles (3.2 km.) southeast of Malade, Oneida County,

Idaho (C. D. Walcott and L. D. Burling, 1906).

Obolus wortheni.
Obolus (Westonia) ella.
Lingulella desiderata.
Acrotreta idahoensis.

Acrotreta idahoensis sulcata.
Billingsella coloradoensis.
Ptychoparia.

Anomocare.

54u. (For stratigraphic position and. association, see p. 149.) Upper Cambrian: Limestone of the St. Charles lime-
stone [Walcott, 1908a, p. 6], about 100 feet (30.5 m.) above the Middle Cambrian, on the north side of Two-
mile Canyon, near its mouth, 2 miles (3.2 km.) southeast of Malade, Oneida County, Idaho (C. D. Walcott

and L. D. Burling, 1906).
*Obolus wortheni.
Acrotreta idahoensis..
Billingsella coloradoensis.
Agnostus.

Ptychoparia 2 sp.
Ptychaspis.
Anomocare.

54v. (For stratigraphic position and association, see p. 150.) Middle Cambrian: Limestone in the lower part of
the Bloomington formation [Walcott, 1908a, p. 7], about 1,600 feet (488'm.) below the Upper Cambrian, on
the south side of Twomile Canyon, near its mouth, 2 miles (3.2 km.) southeast of Malade, Oneida County,

. Idaho (C. D. Walcott and L. D. Burling, 1906).

Obolus wortheni. 9
Ptychoparia 2 sp.

54w (=54t). (For stratigraphic position and association, see p. 149.) (C. D. Walcott and L. D. Burling, 1906.)

Obolus tetonensis ninus.
Obolus wortheni.
Agnostus 2 sp.
Ptychaspis.

| Ptychoparia 2 sp.

Liostracus.
Anomocare 3 sp.
Damesella sp.

LOCALITIES. 205

64x. (For stratigraphic position and association, see p. 149.) Upper Cambrian: St. Charles limestone [Walcott,
1908a, p. 6], about 200 feet (60.4 m.) above the Middle Cambrian, on the north side of Twomile Canyon,
near its mouth, 2 miles (3.2 km.) southeast of Malade, Oneida County, Idaho (GC. D. Walcott and L. D.
Burling, 1906).

Obolus wortheni. Liostracus.
Billingsella wolloneieloeaens Ptychaspis.
Agnostus. Anomocare.

Ptychoparia. Damesella.

54y. (For stratigraphic position and association, see p. 151.) Middle Cambrian: About 510 feet (155.4 m.) above
the Brigham quartzite and 3,680 feet (1,121.7 m.) below the Upper Cambrian, in the limestone forming 2¢
of the Ute limestone [Walcott, 1908f, p. 197], in Blacksmith Fork Canyon, about 10 miles (16.1 km.) east of
Hyrum, Cache County, Utah (C.D. Wale and L. D. Burling, 1906).
Micromitra (Paterina) superba.
Hyolithes.
Ptychoparia.

55. (For stratigraphic position and association, see p. 140.) Middle Cambrian: Shaly limestone at the top of the
Eldorado limestone [Walcott, 1908f, p. 184], east slope of Prospect Mountain, in New York Canyon, Eureka
district [Hague, 1892, Atlas], Eureka County, Nev. (C. D. Walcott, 1886).

Acrotreta definita. Agnostus tumidosus Hall and Whitfield.
Billingsella whitfieldi. Dorypyge ? quadriceps (Hall and Whitfield).
Agnostus bidens Meek.

&5b. (For stratigraphic position and association, see p. 140.) Middle Cambrian: Top of the Eldorado limestone
[Walcott, 1908f, p. 184], west side of Secret Canyon, Eureka district [Hague, 1892, Atlas], Eureka County,
Nev. (C. D. Walcott, 1886).

*Billingsella whitfieldi. Agnostus bidens Meek.
*Orusia? eurekensis. Olenoides expansus (Walcott).
Orusia lenticularis. Zacanthoides spinosus (Walcott).

Stenotheca elongata Walcott.

55¢ (=163). (For stratigraphic position and association, see p. 152.) Middle Cambrian: Spence shale member of
the Ute limestone [Walcott, 1908a, p. 8], about 50 feet (15.2 m.) above the Brigham quartzite and 2,755 feet
(839.7 m.) below the Upper Cambrian, in a ravine running up into Danish Flat from Mill Canyon, about 6
miles (9.6 km.) west-southwest of Liberty and 15 miles (24.2 km.) west of Montpelier, Bear Lake County,
Idaho (Mr. and Mrs. C. D. Walcott, Helen Walcott, Stuart Walcott, and L. D. Burling, 1906).

Micromitra (Iphidella) pannula?. Microdiscus sp.

Obolus (Westonia) ella. Olenoides, several species.
Lingulella desiderata. *Zacanthoides idahoensis Walcott.
Acrothele subsidua. Zacanthoides sp.

Acrotreta definita. Oryctocephalus reynoldsi Reed.
Acrotreta idahoensis sulcata. Oryctocara geikiei Walcott.
*Nisusia rara. Ptychoparia, many species.
Nisusia (Jamesella) spencei. ‘ Bathyuriscus howelli Walcott.
Nisusia (Jamesella) nautes. ; Bathyuriscus productus (Hall and Whitfield).
Hyolithes. Bathyuriscus sp.

Agnostus, several species.

55d. (For stratigraphic position and association, see p. 150.) Middle Cambrian: About 2,000 feet (609.6 m.)
above the Cambrian quartzitic beds, in a shale which is probably to be referred to the Bloomington forma-
tion [Walcott, 1908a, p. 7], on the south side of Twomile Canyon, near its mouth, 2 miles (3.2 km.) south-
east of Malade, Oneida County, Idaho (C. D. Walcott, 1906).

Obolus (Westonia) wasatchensis.

55e (=32p). (For stratigraphic position and association, see p. 152.) Middle Cambrian: Spence shale member
of the Ute limestone, about 100 feet (30.5 m.) above the Brigham quartzite [Walcott, 1908f, p. 197], at the
mouth of the first small canyon south of Wasatch Canyon, east of Lakeview Ranch, 5 miles (8 km.) north
of Brigham, Boxelder County, Utah (C. D. Walcott and L. D. Burling, 1906).

Micromitra (Iphidella) pannula. Ptychoparia piochensis Walcott.

Obolus (Westonia) ella. Zacanthoides idahoensis Walcott

Lingulella desiderata. Neolenus 2 sp.

Acrothele subsidua. Bathyuriscus howelli Walcott.

Eocystites longidactylus Walcott. Bathyuriscus productus (Hall and Whitfield).

Agnostus. Ogygopsis.

206 CAMBRIAN. BRACHIOPODA.

55h (=3lm). (For stratigraphic position and association, see p. 149.) (C. D. Walcott, Stuart Walcott, and L. D.
Burling, 1906.)

Obolus. Agnostus.
Lingulella. 7 Ptychoparia.
Billingsella coloradoensis. Anomocare.

55n (=3lh). (For stratigraphic position and association, see p. 150.) Middle Cambrian: About 1,850 feet (564 m.)
above the Brigham quartzite and 2,350 feet (716 m.) below the Upper Cambrian, in the limestone
forming 2¢ of the Bloomington formation [Walcott, 1908f, p. 195], in Blacksmith Fork Canyon, about 10
miles (16.1 km.) east of Hyrum, Cache County, Utah (C. P. Walcott and L. D. Burling, 1906).
Micromitra sculptilis.
Ptychoparia.
Dorypyge.

55t (=31z). (For stratigraphic position and association, see p. 151.) (F. B. Weeks, 1905.)
Obolus (Westonia) ella.
Acrothele subsidua?.
Acrotreta ophirensis.

55u. (For stratigraphic position and association, see p. 158.) Middle Cambrian: Limestones about 200 feet (61 m.)
above the Lower Cambrian [Walcott, 1908{, p. 171], 0.25 mile (0.4 km.) below the Maxfield mine, in
Big Cottonwood Canyon, on the west front of the Wasatch Mountains, southeast of Salt Lake City, Salt
Lake County, Utah (F. B. Weeks, 1905).
Micromitra (Iphidella) pannula.
*Linnarssonella urania.

56. (For stratigraphic position and association, see p. 139.) Upper? Cambrian: Limestone at Sierra Springs,
eastern base of Lookout Mountain, Eureka district [Hague, 1892, Atlas], Eureka County, Nev. (C. D-
Walcott, 1880).
Lingulella desiderata.
Agnostus prolongus Hall and Whitfield.
Agnostus tumidosus Hall and Whitfield.

56a. Lower Cambrian: A limestone bowlder in the Sillery conglomerate on the south shore of St. Lawrence.
River, 4 miles (6.4 km.) below Quebec, Canada (C. D. Walcott, 1889).
*Nisusia (Jamesella) amii. Ptychoparia cf. subcoronata (Hall and Whitfield).
Olenellus? sp. Ptychoparia sp. i
Olenoides ellsi Walcott.

56b. Lower Cambrian: A limestone bowlder in conglomerate on the south shore of the island of Orleans, below
Quebec; Canada (C. D. Walcott, 1889).
Obolella crassa. Microdiscus connexus Walcott.
Hyolithes americanus Billings. Ptychoparia sp.

56c. (For stratigraphic position and association, see p. 147.) Lower Cambrian: Rome (‘‘Montevallo”’) shale
along road just north of Buck Creek, 1.125 miles (1.8 km.) northeast of Helena, Shelby County, Ala.
(IT. E. Williard, 1906).

*Micromitra (Paterina) major. Pedeumias transitans Walcott.
*Micromitra (Paterina) williardi. *Wanneria halli Walcott.
*Obolus smithi. Agraulos?.

Wimanella shelbyensis. Hyolithes.

56f. (For stratigraphic position and association, see p. 149.) Middle Cambrian: Nounan limestone [Walcott,
1908a, p. 6], on a ridge north of the creek which flows into Mill Canyon from the west, about 5 miles (8 km.):

west-southwest of Liberty and 15 miles (24.2 km.) west of Montpelier, Bear Lake County, Idaho (C. D..

Walcott and L. D. Burling, 1906).

Obolus matinalis. .| Solenopleura.
*Lingulella manticula var. Ptychoparia 2 sp.
Orthotheca. Anomocare.
Agraulos. | Anomocarella.

56g. (For stratigraphic position and association, see p. 149). Upper Cambrian: Limestone of the St. Charles
limestone [Walcott, 1908a, p.6], in the valley of the stream which flows into Mill Canyon from the west,

about 6 miles (9.6 km.) west-southwest of Liberty and 15 miles (24.2 km.) west of Montpelier, Bear Lake: |

County, Idaho (C. D. Walcott and L. D. Burling, 1906).

Obolus discoideus. Platyceras.
Acrotreta idahoensis. Agnostus.
Billingsella coloradoensis. Ptychoparia.

M

LOCALITIES. 207

560. (For stratigraphic position and association, see p. 147.) Middle Cambrian: Limestone in upper third of
Conasauga limestone, South Bessemer, Jefferson County, Ala. (T. E. Williard, 1906).
Acrotreta (same one as in 56u).

56q. (For stratigraphic position and association, see p. 147.) Middle Cambrian: Limestone at the very top of the
Conasauga limestone in quarry at Ketona, about 5 miles (8 km.) northeast of Birmingham, Jefferson County,
Ala. (T. HE. Williard, 1906).
Lingulella quadrilateralis.
Ptychoparia sp.

56u. (For stratigraphic position and association, see p. 147.) Middle Cambrian: Limestone in upper third of
Conasauga limestone 700 feet (213.4 m.) southeast of Valley Creek bridge, near Nineteenth Street Road,
Bessemer, Jefferson County, Ala. (T. E. Williard, 1906).
Acrotreta (same one as in 560).

57. (For stratigraphic position and association, see p. 140.) Middle Cambrian: Shaly limestone of the Zldorado
limestone [Walcott, 1908f, p. 184], at the 700-foot (213.4 m.) level of the Richmond mine, Ruby Hill [Hague,
1892, p. 43 and Pl. I, opposite p. 116], Eureka district, Eureka County, Nev. (C. D. Walcott, 1880).

Lingulella desiderata. Agnostus bidens Meek.
Lingulella punctata. Agnostus richmondensis Walcott.
Acrotreta definita. Agnostus seclusus Walcott.

57b. (For stratigraphic position and association, see p. 140.) Middle Cambrian: Limestones at the north end of
Mineral Hill, just south of Ruby Hill [Hague, 1892, p. 43, and Pl. I, opposite p. 116], Eureka district,
Eureka County, Nev. (C. D. Walcott, 1880).
Lingulella desiderata.

57¢ (=57k). (For stratigraphic position and association, see p. 127.) Middle Cambrian: About 2,500 feet (762 m.)
above the Lower Cambrian and 2,475 feet (754 m.) below the Upper Cambrian, in the limestone forming 1
of the Stephen formation [Walcott, 1908f, p. 209], on Mount Bosworth, north of the Canadian Pacific Rail-
way between Hector and Stephen, on the Continental Divide between British Columbia and Alberta,
Canada (C. D. Walcott and L. D. Burling, 1907).

Micromitra zenobia. Ptychoparia.3 sp.
Obolus mcconnelli. Menocephalus?.
Nisusia alberta var. Neolenus sp.
Hyolithes carinatus Matthew. Bathyuriscus?.

57d. (For stratigraphic position and association, see p. 125.) Upper Cambrian: About 3,215 feet (980 m.) above

the Middle Cambrian and 375 feet (114.3 m.) below the top of the Upper Cambrian,¢in green shales near the

summit of 2b of the Sherbrooke limestone [Walcott, 1908f, p. 204], on ridge west of Mount Bosworth, on the

Continental Divide between Alberta and British Columbia, Canada (C. D. Walcott and L. D. Burling, 1907).
Lingulella isse.

57e. (For stratigraphic position and association, see p. 129.) Lower Cambrian: About 115 feet (35 m.) below the
Middle Cambrian, in limestone correlated with the top of le of the Mount Whyte formation on Mount
Bosworth [Walcott, 1908f, p. 213], just above the tunnel on the north shoulder of Mount Stephen, about
3 miles (4.8 km.) east of Field, British Columbia, Canada (C. D. Walcott and L. D. Burling, 1907).

Acrothele colleni. Albertella sp.
Acrotreta sagittalis taconica. Olenellus canadensis Walcott.
Scenella varians Walcott. Bathyuriscus sp.

Stenotheca elongata Walcott.

57f. (For stratigraphic position and association, see p.127.) Middle Cambrian: About 2,200 feet (670.5 m.) above
the Lower Cambrian and 2,800 feet (853.4 m.) below the Upper Cambrian, in the limestone forming 1 of
the Stephen formation [Walcott, 1908f, p. 209], about 0.5 mile (0.8 km.) east of the great ‘‘fossil bed” on
the northwest slope of Mount Stephen, above Field on the Canadian Pacific Railway, British Columbia,
Canada (C. D. Walcott and L. D. Burling, 1907).

Obolus mcconnelli. Orthotheca sp.
Acrotreta depressa. Scenella varians Walcott.
Nisusia (Jamesella) cf. nautes. Ptychoparia sp.

Hyolithes carinatus Matthew.

@ See the footnote on page 125.

208

CAMBRIAN BRACHIOPODA. -

57g. (For stratigraphic position and association, see p. 128.) Middle Cambrian: About 1,700 feet (518 m.) above
the Lower Cambrian and 3,250 feet (991 m.) below the Upper Cambrian, in the siliceous shales forming
2d of the Stephen formation [Walcott, 1908f, p. 211], on Mount Bosworth, north of the Canadian Pacific
Railway between Hector and Stephen, on the Continental Divide between British Columbia and Alberta,

Canada (C. D. Walcott and L. D. Burling, 1907).

Micromitra (Iphidella) pannula.
Obolus (Westonia) ella.
Cruziana.

Hyolithes.

Leperditia.
Ptychoparia.
Bathyuriscus.

57j. (For stratigraphic position and association, see p. 127.) Middle Cambrian: About 2,000 feet (609.6 m.) above
the Lower Cambrian, in the limestone forming 2 of the Stephen formation [Walcott, 1908c, p. 237 (6)], just
east of the ‘‘fossil bed” on the northwest slope of Mount Stephen, above Field on the Canadian Pacific
Railway, British Columbia, Canada (C. D. Walcott and L. D. Burling, 1907).

Micromitra (Iphidella) pannula.
Nisusia alberta var.
Hyolithes.

Bathyuriscus rotundatus (Rominger).
Neolenus serratus (Rominger).

57k (=57c). (For stratigraphic position and association, see p. 127.) (C. D. Walcott and L. D. Burling, 1907.)

Obolus mcconnelli.
Nisusia alberta var.
Agnostus.

Agraulos.
Ptychoparia.
Neolenus.

57m. (For stratigraphic position and association, see p. 129.) Lower Cambrian: About 50 feet (15 m.) below the
Middle Cambrian, in a siliceous shale correlated with 1b of the Mount Whyte formation on Mount Bosworth
[Walcott, 1908f, p. 213], just above the tunnel on the north shoulder of Mount Stephen, about 3 miles (4.8
km.) east of Field, British Columbia, Canada (C. D. Walcott and L. D. Burling, 1907).

Micromitra (Paterina) sp.
Acrotreta sagittalis taconica.
Nisusia (Jamesella) lowi.
Cystid plates.

Scenella varians Walcott.
Hyolithes.

Hyolithellus cf. micans (Billings).
Olenellus canadensis Walcott.

57%n. (For stratigraphic position and association, see p. 127.) Middle Cambrian: About 3,000 feet (914.4 m.)
above the Lower Cambrian and about 700 feet (213.4 m.) above the base of a limestone correlated with
4 of the Eldon limestone on Mount Bosworth [Walcott, 1908f, p. 209],.on the northwest slope of Mount
Stephen, above Field on the Canadian Pacific Railway, British Columbia (C. D. Walcott and L. D.

Burling, 1907).
Lingulella cf. isse.
Protospongia (spicules).
Hyolithes.

Agnostus cf. montis Matthew.

Zacanthoides spinosus (Walcott).
Ptychoparia.

Bathyuriscus.

Ogygopsis.

57r (=58s). (For stratigraphic position and association, see p. 129.) (L. D. Burling, 1907.)

Micromitra (Paterina) labradorica var.
Micromitra (Iphidella) pannula.

Acrotreta sagittalis taconica.
Ptychoparia 3 sp.

57s. (For stratigraphic position and association, see p. 129.) Lower Cambrian: About 160 feet (49 m.) below the
Middle Cambrian, near the base of the gray oolitic limestone forming 1b of the Mount Whyte formation
[Walcott, 1908f, p. 212], on Mount Bosworth, north of the Canadian Pacific Railway between Hector and
Stephen, on the Continental Divide between British Columbia and Alberta, Canada (C. D. Walcott, 1907).

Nisusia (Jamesella) lowi.
Acrotreta sagittalis taconica.
Microdiscus?.

Agraulos sp.
Ptychoparia sp.

57y. (For stratigraphic position and association, see p. 128.) Middle Cambrian: About 1,900 feet (579 m.) above
the Lower Cambrian and 3,050 feet (930 m.) below the Upper Cambrian, in the siliceous shales forming
2a of the Stephen formation [Walcott, 1908, p. 211], on Mount Bosworth, north of the Canadian Pacific
Railway between Hector and Stephen, on the Continental Divide between British Columbia and
Alberta, Canada (C. D. Walcott and L. D. Burling, 1907).

Obolus (Westonia) ella?.

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}

LOCALITIES. 209

58. (For stratigraphic position and association, see p. 139.) Middle Cambrian: Shaly limestones in upper beds
of Secret Canyon shale, east side of New York and Secret canyons, Eureka district [Hague, 1892, Atlas],
Kureka County, Ney. (C. D. Walcott, 1880).

Micromitra sculptilis. Protospongia fenestrata Salter.
Micromitra (Paterina) crenistria?. Hyolithes primordialis Hall.

Obolus discoideus. Agnostus bidens Meek.

Obolus mera. Agnostus communis Hall and Whitfield.
Obolus meconnelli. Agnostus neon Hall and Whitfield.
Obolus nundina. *Aonostus seclusus Walcott.

*Obolus (Acritis) rugatus. Agnostus tumidosus Hall and Whitfield.
*Lingulella clarkei. Ptychoparia anytus (Hall and Whitfield).
Lingulella desiderata. Ptychoparia haguei (Hall and Whitfield).
*Lingulella punctata. *Ptychoparia leeviceps Walcott.
*Acrothele dichotoma. Ptychoparia? linnarssoni Walcott.
*Acrotreta idahoensis alta. Ptychoparia unisulcatus (Hall and Whitfield)..
Acrotreta microscopica. Ogygia? problematica Walcott.

58f. (For stratigraphic position and association, see p. 125.) Upper Cambrian: About 3,100 feet (945 m.) above
the Middle Cambrian, in the limestone interbedded in the shales forming 2b of the Sherbrooke limestone
[Walcott, 1908f, p. 204], ridge west of Mount Bosworth, on the Continental Divide between Alberta and
British Columbia, Canada (C. D. Walcott and L. D. Burling, 1907).
Obolus sp.

58i. (For stratigraphic position and association, see p. 127.) Middle Cambrian: About 1,225 feet (873 m.) above
the Lower Cambrian, in the shales of the Stephen formation [Walcott, 1908a, p. 3], northeast slope of Castle
Mountain, facing the amphitheater north of the Canadian Pacific Railway, Alberta, Canada (C. D. Walcott
and L. D. Burling, 1907).
Obolus mcconnelli.

58j. (For stratigraphic position and association, seep. 127.) Middle Cambrian: About 1,900 feet (579 m.) above
the Lower Cambrian and 3,100 feet (945 m.) below the Upper Cambrian, near the base of the limestone
forming 2 of the Stephen formation [Walcott, 1908c, p. 238 (7)], on the east side of Mount Stephen, about
3,000 feet (914 m.) above the Canadian Pacific Railway track 3 miles (4.8 km.) east of Field, British
Columbia (C. D. Walcott and L. D. Burling, 1907).

Micromitra (Iphidella) pannula. Agraulos sp.
Obolus meconnelli. Ptychoparia sp.
Acrothele subsidua. Zacanthoides sp.
Acrotreta depressa. Bathyuriscus sp.
Hyolithes sp. Albertella sp.

Agnostus montis Matthew.

58k (same horizon as 58p). (For stratigraphic position and association, see p. 129.) Lower Cambrian: Just below
the Middle Cambrian, in limestones forming 1 of the Mount Whyte formation [Walcott, 1908c, p, 240 (9)],
just above the tunnel on the north shoulder of Mount Stephen, about 3 miles (4.8 km.) east of Field, British
Columbia, Canada (C. D. Walcott and L. D. Burling, 1907).

Acrotreta sagittalis taconica. Hyolithes billingsi Walcott.
Nisusia alberta var. Ptychoparia sp.

*Nisusia (Jamesella) lowi. Crepicephalus sp.
Stenotheca elongata Walcott. Protypus sp.

Scenella varians Walcott. Albertella sp.

Platyceras sp.

681. (For stratigraphic position and association, see p. 128.) Middle Cambrian: About 1,830 feet (557.8 m.) above
the Lower Cambrian, in the limestone forming 3b of the Stephen formation [Walcott, 1908c, p. 238 (7)], on
the east side of Mount Stephen, about 3,000 feet (914.4 m.) above the Canadian Pacific Railway track, 3.5
miles (5.6 km.) east of Field, British Columbia (C. D. Walcott and Mr. and Mrs. L. D. Burling, 1907).

Micromitra zenobia. Hyolithes sp.
Lingulella desiderata. Microdiscus sp.
* Billingsella marion. Ptychoparia sp.

62667°—vor 51, pr 1—12 14

210 CAMBRIAN BRACHIOPODA.

58p (same horizon as 58k). (For stratigraphic position and association, see p. 129.) Lower Cambrian: Drift
block of limestone believed to have come from the limestone forming 1 of the Mount Whyte formation
[Walcott, 1908c, p. 240 (9)], found near the Canadian Pacific Railway track just west of the tunnel, 3 miles
(4.8 km.) east of Field, British Columbia, Canada (C. D. Walcott and L. D. Burling, 1907).
Nisusia alberta var. Hyolithes billingsi Walcott.
Nisusia (Jamesella) lowi. Ptychoparia.

58r. (For stratigraphic position and association, see p. 127.) Middle Cambrian: About 1,800 feet (548.6 m.) above
the Lower Cambrian and 3,200 feet (975.4 m.) below the Upper Cambrian, in the limestones forming 2 of
the Stephen formation [Walcott, 1908f, p. 211], in the amphitheater between Mounts Stephen and Dennis,
above Field on the Canadian Pacific Railway, British Columbia, Canada (C. D. Walcott and L. D. Burling,
1907).
Obolus meconnelli.
Acrotreta depressa.
Hyolithellus annulatus (Matthew).

Ptychoparia.
Neolenus serratus (Rominger).
Ogygopsis klotzi (Rominger).

58s (=57r). (For stratigraphic position and association, see p. 129.) Lower Cambrian: About 150 feet (46 m.)
below the Middle Cambrian, near the base of the limestones forming 3 of the Mount Whyte formation [Wal-
cott, 1908c, p. 241 (10)], just above the tunnel on the north shoulder of Mount Stephen, about 3 miles
(4.8 km.) east of Field, British Columbia, Canada (C. D. Walcott and L. D. Burling, 1907).

Micromitra (Paterina) labradorica var. Acrotreta sagittalis taconica.
Micromitra (Iphidella) pannula. Ptychoparia 3 sp.

58t. (For stratigraphic position and association, see p. 129.) Lower Cambrian: Sandy shale about 150 feet (45.7 m.)
below the Middle Cambrian, just below the big cliff on the east shoulder of Castle Mountain, north of the
Canadian Pacific Railway, Alberta, Canada (L. D. Burling and Stuart Walcott, 1907).
Obolus parvus.

58w. (For stratigraphic position and association, see p. 127.) Middle Cambrian: About 1,300 feet (396 m.) above
the Lower Cambrian, in the shales of the Stephen formation [Walcott, 1908a, p. 3], northeast slope of Castle
$ Mountain, facing the amphitheater north of the Canadian Pacific Railway, Alberta, Canada (C. D. Wal-
cott and L. D. Burling, 1907).
Obolus meconnelli.

58z. (For stratigraphic position and association, see p. 128.) Middle Cambrian: About 1,875 feet (572 m.) above
the Lower Cambrian and 3,100 feet (945 m.) below the Upper Cambrian, in the limestone forming 2b of the
Stephen formation [Walcott, 1908f, p. 211], on Mount Bosworth, north of the Canadian Pacific Railway

between Hector and Stephen, on the Continental Divide between British Columbia and Alberta, Canada’

(C. D. Walcott and L. D. Burling, 1907).
Micromitra zenobia.
Nisusia alberta var.
Menocephalus.

Ptychoparia.
Neolenus.

59. (For stratigraphic position and association, see p. 140.) Middle Cambrian: Limestone at the base of the western
slope of Combs Peak, near the plain of Antelope Valley, Eureka district [Hague, 1892, Atlas], Eureka County,
Nev. (C. D. Walcott, 1880).
Lingulella arguta. Agnostus tumidosus Hall and Whitfield.
Acrotreta attenuata. Dorypyge ? quadriceps (Hall and Whitfield).

59f. (For stratigraphic position and association, see p. 152.) Middle Cambrian: Limestones immediately under-
lying the Spence shale member of the Ute limestone [Walcott, 1908a, p. 8], ir a saddle north of the creek
which flows into Mill Canyon from the west, about 5 miles (8 km.) west-southwest of Liberty and 15 miles
(24.2 km.) west of Montpelier, Bear Lake County, Idaho (C. D. Walcott, jr., and L. D. Burling, 1907).

Micromitra (Iphidella) pannula. Anomocare sp.
Lingulella desiderata. Ptychoparia sp.
Acrotreta pyxidicula, Agraulos sp.
Solenopleura sp. Stenotheca sp.
Neolenus sp. Zacanthoides sp.

59g. (For stratigraphic position and association, see p. 151.) Middle Cambrian: Limestones immediately over-
lying the Spence shale member of the Ute limestone [Walcott, 1908a, p. 8], in a saddle north of the creek
which flows into Mill Canyon from the west, about 5 miles (8 km.) west-southwest of Liberty and 15 miles
(24.2 km.) west of Liberty, Bear Lake County, Idaho (C. D. Walcott, jr., and L. D. Burling, 1907).

Lingulella sp. Neolenus.

Acrothele subsidua. Microdiscus.

Acrotreta cf. idahoensis. Zacanthoides idahoensis Walcott.
Ptychoparia 3 sp. Menocephalus.

4

LOCALITIES. 211

59m. (For stratigraphic position and association, see p. 147.) Lower Cambrian: Weisner quartzite in the Roan
iron mine, Bartow County, Ga. (S. W. McCallie, 1900).
Obolella cf. atlantica. Stenotheca cf. rugosa (Hall).
Obolella cf. crassa. Olenellus thompsoni (Hall).
Archocyathus?.

60. (For stratigraphic position and association, see p. 1389.) Middle Cambrian: Limestones in upper beds of
Secret Canyon shale, across the canyon from the dump of the old Richmond mine shaft, Eureka district
[Hague, 1892, Atlas], Eureka County, Nev. (C. D. Walcott, 1880).
Lingulella clarkei. Agnostus prolongus Hall and Whitfield.
Lingulella desiderata. Ptychoparia maculosa (Hall and Whitfield).
Lingulella sp. Ptychoparia unisulcata (Hall and Whitfield).
Acrotreta pyxidicula.

60b. (For stratigraphic position and association, see p. 130.) Lower Cambrian: About 2,300 feet (702 m.) below

the Mount Whyte formation and 200 to 300 feet (61 to 92 m.) above the Lake Louise shale, in the St. Piran sand-

stone [Walcott, 1908a, p. 4], at Vermilion Pass, on the Continental Divide between British Columbia and

Alberta, west-southwest of Castle on the Canadian Pacific Railway, Alberta, Canada (C. D. Walcott, 1909).
* Obolella vermilionensis.
Wanneria gracile Walcott.

61. (For stratigraphic position and association, see p. 139.) Upper Cambrian: Limestone in the Dunderberg shale
[Walcott, 1908f, p. 184], a little south of the Hamburg mine, Eureka district [Hague, 1892, Atlas], Eureka
County, Nev. (C. D. Walcott and C. H. H., 1882). :

Micromitra sculptilis. Acrotreta idahoensis alta.

Obolus anceps. *A crotreta spinosa.

Obolus meera. Acrotreta sp.

Obotus nundina. Agnostus prolongus Hall and Whitfield.
Lingulella desiderata. Agnostus tumidosus Hall and Whitfield.
Lingulella manticula. Ptychoparia granulosa (Hall and Whitfield).
Lingulella punctata. Ptychoparia maculosa (Hall and Whitfield).
Acrotreta attenuata. Ptychoparia unisulcata (Hall and Whitfield).
Acrotreta idahoensis.

62. (For stratigraphic position and association, see p. 139.) Upper Cambrian: Limestone in the Dunderberg shale
[Walcott, 19081, p. 184], in canyon immediately north of Adams Hill, Eureka district [Hague, 1892, Attas],
Eureka County, Ney. (C. D. Walcott, 1880).

Micromitra sculptilis. Acrotreta spinosa.

Obolus discoideus. Agnostus prolongus Hall and Whitfield.
’ Lingulella manticula. Ptychoparia breviceps (Walcott).

Lingulella punctata. Arethusina americana Walcott.

62a. (For stratigraphic position and association, see p. 139.) Upper Cambrian: Limestone on east side of Sierra
Canyon, opposite the Jackson mine, Eureka district [Hague, 1892, Atlas], Eureka County, Nev. (C. D.
Walcott, 1880).
Acrotreta spinosa.
Ptychoparia granulosa (Hall and Whitfield).
Ptychoparia simulator (Hall and Whitfield).

68. _ (For stratigraphic position and association, see p. 139.) Lower Ordovician: At the base of the Pogonip lime-
stone northeast of Adams Hill, Eureka district [Hague, 1892, Atlas], Hureka County, Nev. (C. D. Walcott,

1880).
*Obolus anceps. Schizambon?.
*Elkania ambigua. Syntrophia nundina.

Acrotreta idahoensis alta.-

64. (For stratigraphic position and association, see p. 139.) Upper Cambrian: Limestone near the Bullwhacker
mine, Eureka district [Hague, 1892, Atlas], Eureka County, Nev. (C. D. Walcott, 1880).
Obolus discoideus.
Obolus (Westonia) iphis.
Agnostus prolongus Hall and Whitfield.

65. (For stratigraphic position and association, see p. 139.) Upper Cambrian: Limestone on the east side of Sierra
Canyon, opposite Pinnacle Peak, Eureka district [Hague, 1892, Atlas], Eureka County, Nev. (Arnold Hague
and J. P. Iddings, 1880).
Acrotreta idahoensis alta.
Acrotreta spinosa.

212

CAMBRIAN BRACHIOPODA.

66. (For stratigraphic position and association, see p. 139.) Upper Cambrian: Dunderberg shale [Walcott,
1908f, p. 184], on the first ridge north of the Dunderberg mine, Eureka district [Hague, 1892, Atlas], Hureka

County, Ney. (C. D. Walcott, 18

Obolus discoideus.

Agnostus prolongus Hall and Whitfield.

Arethusina americana Walcott.

67 (=67c). Upper Cambrian: Sandstone on Tatur Hill, 7 miles (11.2 km.) northwest of Burnet, Burnet County,

Tex. (C. D. Walcott, 1884).

Obolus matinalis.

Obolus sinoe.

Lingulella acutangula.
Acrotreta microscopica.
Ptychoparia affinis (Walcott).
Ptychoparia diademata (Hall).

67c (=67).
Obolus matinalis.
Lingulella acutangula.
Lingulella perattenuata.

Ptychoparia Manoensis Walcott.
Ptychoparia? metra Walcott.
Ptychoparia? urania Walcott.
Ptychoparia wisconsinensis (Owen).
Anomocare pero (Walcott).

67z. Upper Cambrian: Sandstone at west base of Tatur Hill, 7 miles (11.2 km.) northwest of Burnet, Burnet

County, Tex. (C. D. Walcott, 1884).

Obolus matinalis.
Ptychoparia burnetensis Walcott.

68 (=68e, 68y, and 68z). Upper Cambrian: Interbedded sandstone and limestone, Packsaddle Mountain, Llano

County, Tex. (C. D. Walcott, 1884).

Obolus matinalis.

Obolus tetonensis ninus.
Lingulella acutangula.

Acrotreta microscopica.
Billingsella coloradoensis.
Eoorthis indianola?.

Eoorthis remnicha texana.
Eoorthis wichitaensis.

Eoorthis wichitaensis leviusculus.
*Huenella texana.

68e (=68).
Lingulella acutangula.
Acrotreta microscopica.
Billingsella coloradoensis.

68y (=68).
Obolus sinoe.
Lingulella perattenuata.

68z (=68).
Obolus matinalis.

Platyceras texanum Walcott.
Ptychoparia affinis (Walcott). .
Ptychoparia diademata (Hall).
Ptychoparia llanoensis Walcott.
Ptychoparia similis Walcott.
Ptychoparia? urania Walcott.
Agraulos conyvexus Whitfield.
Anomocare pero (Walcott).
Chariocephalus sp.

69. Upper Cambrian: Limestone near Honey Creek, Burnet County, Tex. (C. D. Walcott, 1884).

Obolus sinoe.

Lingulella acutangula.

Lingulella texana.

Lingulella (Lingulepis) acuminata.
Acrotreta microscopica.
Billingsella coloradoensis.
*Syntrophia alata.

Huenella texana.

Huenella texana leviusculus.

Capulus sp.

Ptychoparia affinis (Walcott).

Ptychoparia diademata (Hall).

Ptychoparia llanoensis Walcott.

Anomocare pero (Walcott).

Pterocephalia sancti-sabze Roemer.
Chariocephalus tumifrons Hall and Whitfield.

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LOCALITIES. 213

70 (=70a and 70e). Upper Cambrian: Limestone near Morgans Creek, Burnet County, Tex. (C. D. Walcott, 1884).
Obolus sinoe. Ptychoparia perseus Hall var.
Lingulella acutangula. Ptychoparia romerei (Shumard).
Lingulella perattenuata. Ptychoparia suada Walcott.
*Lingulella texana. Ptychoparia wisconsinensis (Owen).
Lingulella (Lingulepis) acuminata. Agraulos convexus Whitfield.
Billingsella coloradoensis. Anomocare pero (Walcott).
Capulus?. Pterocephalia sancti-sabze Roemer.
Cystidean plates. Chariocephalus tumifrons Hall and Whitfield.
Ptychoparia diademata (Hall) Ptychaspis granulosa (Owen).
Ptychoparia pattersoni Hall.

70a (=70).
Billingsella coloradoensis.
Tllenurus? dia Walcott.
Ptychoparia occidens Walcott.

Ptychoparia wisconsinensis (Owen).
Dikellocephalus belli Billings.
Dikellocephalus minnesotensis Owen.

70e (=70).
Lingulella acutangula.
*Acrotreta microscopica.
Billingsella coloradoensis.

71. Upper Cambrian: Limestone in Cold Creek Canyon, Burnet County, Tex. (C. D. Walcott, 1884).
Obolus matinalis. Eoorthis wichitaensis.
Obolus sinoe. Huenella texana.
Acrotreta microscopica. *Huenella texana leeviusculus.
Billingsella coloradoensis. Ptychoparia affinis (Walcott).
Hoorthis iddingsi. Ptychoparia wisconsinensis (Owen).
Hoorthis indianola. Agraulos convexus Whitfield.
*Hoorthis remnicha texana. Anomocare pero (Walcott).

72 (same horizon as 72a). Lower Cambrian: Limestone 5 miles (8 km.) east of Albany, Rensselaer County, N. Y.
(C. D. Walcott and T. N. Dale, 1893).
Obolus prindlei.

72a (same horizon as 72). Lower Cambrian: Limestone 1 mile (1.6 km.) southwest of Wynantskill, Rensselaer
County, N. Y. (L. M. Prindle, 1893).
*Obolus prindlei.

73. Middle Cambrian: Sandstones of the Tonto group in Kwagunt Valley, Grand Canyon of the Colorado, Ariz.
(C. D. Walcott, 1882).
Obolus (Westonia.) chuarensis.

*Lingulella lineolata.

73a. Middle Cambrian: ‘‘Tonto” sandstone in Chuar Valley, Grand Canyon of the Colorado, Ariz. (C. D. Wal-
cott, 1882).

*Micromitra (Paterina) superba.

Micromitra (Iphidella) pannula.

*Obolus (Westonia) chuarensis.
Lingulella lineolata.

78b. Middle Cambrian: Sandstone in upper part of the Tonto group, lower portion of Kwagunt Valley, Grand
Canyon of the Colorado, Ariz. (C. D. Walcott, 1882).
Micromitra (Paterina) crenistria.

74. Middle Cambrian: Sandstone about 300 feet (91.4 m.) above the base of the Tonto group at the head of
Nunkoweap Valley, Grand Canyon of the Colorado, Ariz. (C. D. Walcott, 1882).

Micromitra pealei.

*Micromitra (Paterina) crenistria.
Micromitra (Paterina) superba.
Micromitra (Iphidella) pannula.
*Obolus zetus.

Obolus (Westonia) chuarensis.
*Obolus (Westonia) euglyphus.
Lingulella lineolata.

Lingulella perattenuata.
*Billingsella obscura.

74b. Middle Cambrian: Sandstone 1,000 feet (305 m.) above the base of the Tonto group, Nunkoweap Valley,
Grand Canyon of the Colorado, Ariz. (C. D. Walcott).

Obolus (Westonia) chuarensis.

214 CAMBRIAN BRACHIOPODA.

74c. Middle Camprian: ‘‘Tonto” sandstone at the head cf Lava Canyon, Grand Canyon of the Colorado, Axiz.

(C. D. Walcott, 1883).
Obolus (Westonia) euglyphus.

74d. Middle Cambrian: Sandstone beds in ‘‘Tonto”’ shale just above massive sandstones, near mouth of Bass
Canyon, on the south side of the Grand Canyon of the Colorado, southeast of Powells Plateau, Ariz. (C. D.
Walcott, 1901).
Micromitra (Paterina) superba. Lingulella perattenuata.
Micromitra (Iphidella) pannula. *Lingulella (Lingulepis) spatula.
Lingulella lineolata.

75. Upper Cambrian: Thin-bedded limestones below the base of the Ordovician in the Tonto group, near the
water’s edge at the mouth of Kanab Canyon, Grand Canyon of the Colorado, Ariz. (C. D. Walcott, 1879).
Obolus zetus.
Lingulella winona convexa.
*Nisusia? (Jamesella?) kanabensis.

*Protorthis sp. undt. | These species may not occur in the same bed.

76. Upper Cambrian: Arenaceous limestone at Hoyt’s quarry, 4 miles (6.4 km.) west of Saratoga Springs, Sara-
toga County, N. Y. (C. D. Walcott and Cooper Curtice, 1883).
Lineulella (Lingulepis) acuminata.
Dikellocephalus.

76a. Upper Cambrian: Arenaceous limestone in a railroad quarry 1 mile (1.6 km.) north of Saratoga Springs,
Saratoga County, N. Y. (C. D. Walcott and Cooper Curtice, 1883).
Lingulella (Lingulepis) acuminata.

77, Upper Cambrian: Sandstone near the water below the falls at the high bridge, and also at several horizons
in the section, the highest point being 70 to 75 feet (21 to 22 m.) above the water, in Ausable Chasm, Essex
County, N. Y. (C. D. Walcott and Cooper Curtice, 1883 and 1886).
*Linegulella prima.
Lingulella (Lingulepis) acuminata.

78 (=78s). Upper Cambrian: “‘St. Croix sandstone,’ quarry near St. Croix River, in suburbs of Osceola, Polk
County, Wis. (L. C. Wooster, 1883).

Obolus (Westonia) aurora. *Finkelnburgia osceola.
Lingulella mosia. *Finkelnburgia osceola corrugata.
*Lingulella mosia osceola. Syntrophia barabuensis.
Lingulella winona. Illenurus quadratus Hall.
*Lingulella winona convexa. Spirodentalium osceola Walcott.
Billingsella coloradoensis. Bellerophon antiquatus Whitfield.

Finkelnburgia finkelnburgi.

78a. Upper Cambrian: ‘“‘St. Croix sandstone” in the topmost quarry on Mount Washington, near Eau Claire,
Eau Claire County, Wis. (L. C. Wooster, 1883).

Obolus sp. undt. *Acraulos? thea Walcott.
Dicellomus pectenoides. Crepicephalus iowensis (Hall).
Dicellomus politus.

78b. Upper Cambrian: ‘‘St. Croix sandstone” 50 feet (15.2 m.) above St. Croix River, near the landing at
Osceola, Polk County, Wis. (Cooper Curtice, 1884).
Lingulella mosia.
Lingulella similis.
Finkelnburegia osceola.

78c. Upper Cambrian: “St. Croix sandstone” at Osceola, Polk County, Wis. (C. Schuchert, 1893).
Obolus (Westonia) aurora. Lingulella winona.
Lingulella oweni: Lingulella winona convexa.
78d. Upper Cambrian: The upper portion of the ‘St. Croix sandstone” exposed in the blufis at La Crosse,
La Crosse County, Wis. (C. D. Walcott, 1898).
Obolus matinalis.

78s (=78). (C. Schuchert, 1893.)

Obolus (Westonia) aurora. Finkelnburgia finkelnburgi.
Lingulella mosia. Finkelnburgia osceola.
Lingulella mosia osceola. Finkelnburgia osceola corrugata.

Lingulella winona convexa.

LOCALITIES. 215

79. Upper Cambrian: ‘‘St. Croix sandstone” in bluff near Hudson, St. Croix County, Wis. (L. C. Wooster, 1883).

Obolus matinalis. Lingulella winona conyexa.
*Obolus mickwitzi. Lingulella (Lingulepis) acuminata.
Obolus (Westonia) aurora. Billingsella coloradoensis.
Lingulella mosia. Ptychoparia wisconsinensis (Owen).

Lingulella winona.

79’ (=79, though from a slightly different horizon). (Chas. Schuchert, 1893.)
Obolus matinalis.
Obolus mickwitzi.

79a. Upper Cambrian: “‘St. Croix sandstone,” quarry and ledge 0.5 mile (0.° km.) southeast of the county
courthouse, Menomonie, Dunn County, Wis. (L. C. Wooster, 1883).
Lingulella winona conyexa. Hoorthis sp.
*Protorthis lzevis. Finkelnburegia osceola.
Billingsella coloradoensis. :

79b. Upper Cambrian: ‘‘St. Croix sandstone”’ in shaly beds 4 feet (1.2 m.) above the water, near Hudson, St.
Croix County, Wis. (J. F. James, 1889).
Obolus matinalis. Lingulella (Lingulepis) acuminata.
Obolus mickwitzi. Finkelnburgia osceola.

79s. Upper Cambrian: ‘‘St. Croix sandstone’”’ in bluff near Hudson, St. Croix County, Wis. (C. Schuchert,
1893).
Lingulella mosia.
Dicellomus politus.

79x. Middle Cambrian: “‘St. Croix sandstone’’ near the flour mill on Beaver Creek, north of Galesville, Trem-
pealeau County, Wis. (Cooper Curtice, 1882; L. C. Wooster, 1883). (See p. 159.)
Lineulella (Lingulepis) acuminata.
Dicellomus politus.

80. Upper Cambrian: ‘‘St. Croix sandstone”’ 0.66 mile (1.1 km.) southwest of the railway depot, Menomonie,
Dunn County, Wis. (L. C. Wooster, 1883).
Lingulella ampla. Dicellomus politus.
Lingulella winona convexa. Finkelnburgia osceola.

80a. Upper Cambrian: ‘‘St. Croix sandstone’’ 4 miles (6.4 km.) north of Reedsburg, Sauk County, Wis. (L. C.
Wooster, 1883).
Lingulella similis. Hoorthis remnicha sulcata.
Billingsella coloradoensis. Finkelnburgia osceola.
*Eoorthis remnicha.

81. Upper Cambrian: ‘St. Croix sandstone’’ 1 mile (1.6 km.) east-northeast of Devils Lake, Sauk County, Wis.
(L. C. Wooster, 1883).
Finkelnburgia finkelnburgi.

81b. Upper Cambrian: ‘‘St. Croix sandstone’’ near Devils Lake, Sauk County, Wis. (Cooper Curtice, 1884).
Obolus (Westonia) stoneanus. Finkelnburgia finkelnburei.
*Hoorthis diablo. Syuntrophia barabuensis.

81o. Upper Cambrian: ‘‘St. Croix sandstone’’ on the railroad track below the Cliff House, Devils Lake, Sauk
County, Wis. (J. F. James, 1889).
Syntrophia barabuensis.

82 (see 82s). Upper Cambrian: ‘‘St. Croix sandstone” on the bank of St. Croix River, at St. Croix Falls, Polk
County, Wis. (L. C. Wooster, 1883).
Lingulella (Lingulepis) acuminata.
82a. Upper Cambrian: “‘St. Croix sandstone’’ 25 feet (7.6 m.) above the water level, near the Knapp, Stout and
Company’s buildings, Menomonie, Dunn County, Wis.
-Obolus matinaiis.
Lingulella phaon.

82b (see 339d; may be same locality). Upper Cambrian: “‘St. Croix sandstone’’ along the railroad track near
Taylors Falls, Chisago County, Minn. (W. A. Finkelnburg).
*Curticia elegantula.
Obolus matinalis.
Dicellomus politus

216 | CAMBRIAN BRACHIOPODA.

82c. Upper Cambrian: Conglomerate beds in the “‘St. Croix sandstone” in point below enSOet Chisago
County, Minn. (W. A. Finkelnburg).
Lingulella similis.

82s (see 82). Upper Cambrian: “‘St. Croix sandstone’? on the bank of St. Croix River, St. Croix Falls, Polk
County, Wis. (C. Schuchert, 1893).
Obolus matinalis.
Lingulella (Lingulepis) acuminata.

83. Upper Cambrian: “‘St. Croix sandstone’ near Trempealeau, Trempealeau County, Wis. (Cooper Curtice
and G. H. Squiers, 1884). .

Obolus matinalis. Finkelnburgia osceola.
Dicellomus politus. Syntrophia barabuensis.
EKoorthis diablo. Chariocephalus whitfieldi Hall.

*Finkelnburgia finkelnburgi.

83! (=135c). (Chas. Schuchert, 1893.)
Billingsella coloradoensis.
Finkelnburgia finkelnburgi.
Finkelnburgia osceola.

83°. Upper Cambrian: Green-sand horizon in the “‘St. Croix sandstone,” below the ‘‘fifth trilobite bed” of
Owen, at Trempealeau, Trempealeau County, Wis. (Chas. Schuchert, 1893).
Billingsella coloradoensis.
Chariocephalus whitfieldi Hall.

834. Middle Cambrian: ‘‘St. Croix sandstone,’’ in beds characterized by the presence of Crepicephalus iowensis,
at Trempealeau, Trempealeau County, Wis. (C. Schuchert, 1893). (See p. 159.)
Obolus matinalis.

84. Middle Cambrian: “‘St. Croix sandstone’ at Dresbach, opposite the mouth of Black River, Winona County,
Minn. (Cooper Curtice, 1884). (See p. 159.)

Obolus namouna. Lingulella (Lingulepis) acuminata.
Obolus rhea. Dicellomus politus.
Lingulella ampla.

84a. Upper Cambrian: “St. Croix sandstone,’’ River Junction, Houston County, 20 miles (32.2 km.) below
Dresbach, Minn. (Cooper Curtice, 1884).
Lingulella phaon.2
Billingsella coloradoensis.
Syntrophia primordialis.

Dikellocephalus misa Hall.
Chariocephalus whitfieldi Hall.

84f. Middle Cambrian: ‘‘St. Croix sandstone’’ at Dresbach, opposite the mouth of Black River, Winona
County, Minn. (W. A. Finkelnburg, 1897). (See p. 159.)
Lingulella ampla.
Dicellomus politus.
84s. Middle Cambrian: “‘St. Croix sandstone’? near Dakota, Winona County, Minn. (Chas. Schuchert, 1893).
(See p. 159.)
Lingulella ampla.
Lingulella (Lingulepis) acuminata.
Dicellomus politus.
85 (=85s). Upper Cambrian: ‘‘St. Croix sandstone” at Prairie du Sac, Sauk County, Wis. (Cooper Curtice, 1884).
Obolus (Westonia) stoneanus.
*Lingulella mosia.

85a. Upper Cambrian: ‘St. Croix sandstone” at Brown’s quarry, Prairie du Sac, Sauk County, Wis. (Cooper
Curtice, 1884).
Lingulella oweni.

85s (=85, though possibly from a slightly different bed). Upper Cambrian: ‘“‘St. Croix sandstone” at Prairie du
Sac, Sauk County, Wis. (Chas. Schuchert, 1893).

Obolus (Westonia) aurora. Lingulella winona convexa.

*Obolus (Westonia) stoneanus. Ilenurus quadratus Hall.

Lingulella mosia. Dikellocephalus minnesotensis Owen.
Lingulella oweni. Dikellocephalus pepinensis Owen.

Lingulella winona.

a May be from a horizon different from that of the other species.

LOCALITIES. 217

85x. Upper Cambrian: Upper beds of the “‘St. Croix sandstone” near Mazomanie, Dane County, Wis. (Chas.
Schuchert, 1893).

Obolus (Westonia) stoneanus. Lingulella winona convexa.
Lingulella mosia. Finkelnburgia osceola.
Lingulella winona. Dikellocephalus sp.

S85x (—85x, though possibly from a slightly different bed).
*Obolus (Westonia) aurora.
Lingulella mosia.
Lingulella winona convexa.

85z. Upper Cambrian: ‘St. Croix sandstone” at Madison, Dane County, Wis. (L. C. Wooster, 1883; Cooper Cur-
tice, 1884; and J. James, 1889).
Lingulella oweni.

86. Upper Cambrian: “St. Croix sandstone” at Van Ness quarry, Gibraltar Bluff, Lodi, Columbia County, Wis.
(L. C. Wooster, 1883; Cooper Curtice, 1884).
Obolus (Westonia) aurora.
Lingulella mosia.
*Lingulella oweni.

86a. Upper Cambrian: “St. Croix sandstone” near Red Wing, Goodhue County, Minn. (Cooper Curtice, 1884).
Lingulella similis. *Otusia sandbergi.
Billingsella coloradoensis. *Hoorthis remnicha.@

87. Lower Cambrian: Limestone 1 mile (1.6 km.) south-southwest of Highgate Falls, Franklin County, Vt. (C. D.
Walcott, 1885).
Micromitra (Paterina) labradorica swantonensis.
Obolus? sp. undt.
*Lingulella franklinensis.

87’. Upper Cambrian: Limestone 1 mile (1.6 km.) south-southwest of Highgate Fails, Franklin County, Vt.
*Obolus sp. undt. d. ; :

This species is labeled as coming from locality No. 87, but horizon is given as Upper Cambrian instead of Lower
Cambrian.

88a. Middle Cambrian: Limestone about 100 feet (30.5 m.) above the quartzitic sandstone at the base of the
Cambrian, in the northern suburbs of Deadwood, in the Black Hills, South Dakota (C. D. Walcott; 1887).

Lingulella ampla. Acrotreta idahoensis.
Lingulella desiderata. Ptychoparia vacuna Walcott.
*Lingulella similis. Liostracus panope (Walcott).

*Linnarssonella girtyi.

89. (For stratigraphic position and association, see p. 147.) Middle Cambrian: Limestone in Murphrees Valley,
Blount County, Ala. (A. M. Gibson, 1884).
Lingulella (Lingulepis) acuminata.
*Dicellomus appalachia.
90. (For stratigraphic position and association, see p. 147.) Middle Cambrian: Conasauga (‘‘Coosa”’) shale on
Edward’s farm, near Craigs Mountain, about 10 miles (16.1 km.) southeast of Center, Cherokee County, Ala.
(Cooper Curtice, 1885).

Micromitra (Paterina) major. *Wimanella? anomala.
Obolus (Westonia) ella. Olenoides curticei Walcott.
Lingulella similis?. Olenoides sp.

Acrotreta kutorgai.

90a. (For stratigraphic position and association, see p. 147.) Middle Cambrian: Shales at Cedar Bluff, Cherokee
County, Ala. (Bufford, 1892).
Dicellomus appalachia.
90b. (For stratigraphic position and association, see p. 147.) Middle Cambrian: Conasauga limestone in cut on
Louisville and Nashville Railroad, near Woodstock, Bibb County, Ala. (Chas. Butts, 1904).

Lingulella buttsi. Acrotreta kutorgai.
Lingulella desiderata. Agnostus.
Dicellomus appalachia. Ptychoparia.

90c. (Forstratigraphic position and association, see p. 147.) Middle Cambrian: Conasauga limestone near Kimbrel,
Bibb County, Ala. (Chas. Butts, 1904).
*Lingulella buttsi.

@ Winchell [1886, p. 317] gives the type locality as St. Croix sandstone in sewer excavations at the corner of Brush and Main streets, Red Wing, Minn.

218 CAMBRIAN BRACHIOPODA.

90x (=94a). (For stratigraphic position and association, see p. 147.) Middle Cambrian: In and attached to the
outer surface of siliceous nodules in the Conasauga (‘‘Coosa’’) shale, Coosa Valley, east of Center, Cherokee
County, Ala. (A. M. Gibson, 1884, and Cocper Curtice, 1885).

Micromitra alabamaensis. Anomocare.

*Lingulella hayesi. Olenoides curticei Walcott.
*Acrothele bellula. Laotira cambria Walcott.
*Acrotreta kutorgal. Brooksella alternata Walcott.
Ptychoparia. :

91. (For stratigraphic position and association, seep. 147.) Middle Cambrian: Conasauga (‘Coosa’) shale at Cedar
Bluff, Cherokee County, Ala. (A. M. Gibson, 1884, and Cooper Curtice, 1885).
Obolus willisi. *Lingulella quadrilateralis.
Lingulella nanno. Dicellomus appalachia.

92b (the specimens are labeled 1092b). Upper Cambrian: Limestone on Buffalo Creek, 2 miles (3.2 km.) south-
east of Buffalo Mills, Rockbridge County, Va. (C. D. Walcott, 1898).
Obolus matinalis.
Lingulella (Lingulepis) acuminata.

92x. (For stratigraphic position and association, see p. 147.) Middle Cambrian: Conasauga (*‘Coosa’’) shale at
' Yanceys Bend, Coosa River, southeast of Center, Cherokee County, Ala. (Cooper Curtice, 1885).
Obolus sinoe.
Lingulella similis?.

93. (For stratigraphic position and association, see p. 147.) Upper Cambrian: Shales and limestones at the base
of the Knox dolomite near Jordan’s, just below the ford on Cowan Creek, about 8 miles (12.8 km.) southeast
of Center, Cherokee County, Ala. (Cooper Curtice, 1885).
Obolus willisi.
Lingulella desiderata.

93a. (For stratigraphic position and association, see p. 147.) Upper Cambrian: Shales and limestones at the base

of the Knox dolomite on Terrapin Creek road from Center to Amberson, Cherokee County, Ala. (Cooper

Curtice, 1885). :
Lingulella desiderata?.

98n (16 of section). (For stratigraphic position and association, see p. 147.) Upper Cambrian: Shales in the south-
ern part of Jordan’s farm, near Jordan’s crossroads, about 8 miles southeast of Center, Cherokee County, Ala.
(Cooper Curtice, 1885).
Obolus willisi.

980 (=93). (For stratigraphic position and association, see p. 147.) (Cooper Curtice, 1885.)
Lingulella desiderata.

93x. (For stratigraphic position and association, see p. 147.) Upper Cambrian: Shales on the Clarke farm, near the
ford across Cowan Creek, about 2 miles (3.2 km.) north of Jordan’s crossroads, southeast of Center, Cherokee
County, Ala. (Cooper Curtice, 1885).
Obolus willisi.

94 (see 94a, 940, 94x, and 94xx; 8} of section). (For stratigraphic position and association, see p. 147.) Middle
Cambrian: Shales 0.25 mile (0.4 km.) beyond Steel Ford, Cowan Creek, about 8 wafllas (12. 8 km.) southeast
of Genter, Cherokee County, Ala. (Cooper Curtice, 1885).
*Micromitra alabamaensis.
Obolus willisi.

94a (=shales in which nodules of 90x are embedded; see 94, 940, 94x, and 94xx; 9 of section). (or stratigraphic
position and association, see p. 147.) (Cooper Curtice, 1885.)
Micromitra alabamaensis.
Obolus willisi.
Lingulella hayesi.

940 (see 94, 94a, 94x, and 94xx; 12 of section). (For stratigraphic position and association, see p. 147.) Upper
Cambrian: Limestone at base of dolomite 0.25 mile (0.4 km.) beyond Givens Ford, Cowan Creek, about
8 miles (12.8 km.) southeast of Center, Cherokee County, Ala. (Cooper Curtice, 1885).
Micromitra alabamaensis.
Lingulella desiderata.
Acrotreta sp.

LOCALITIES.

94x (see 94, 94a, 940, and 94xx).

(For stratigraphic position and association, see p. 147.)

219

Middle Cambrian: Shales

0.06 mile (0.1 km.) south of Givens mill, Cowan Creek, about 8 miles (12.8 km.) southeast of Center, Cherokee

County, Ala. (Cooper Curtice, 1885).
Acrothele bellula.

94xx (see 94, 94a, 940, and 94x; 10 of section).

(For stratigraphic position and association, see p. 147.) Middle

Cambrian: Limestone at base of dolomite at Givens mill, Cowan Creek, about 8 miles (12.8 km.) south-
east of Center, Cherokee County, Ala. (Cooper Curtice, 1885).

Lingulella desiderata.
Acrotreta sp.

95a. (For stratigraphic position and association, see p
tram crossing north of the Center road, Cowan
(Cooper Curtice, 1885).

Micromitra alabamaensis.

96. (For stratigraphic position and association, see p.

. 147.) Middle Cambrian: Shales on Spring Creek, near old

Creek valley, southeast of Center, Cherokee County, Ala.

147.) Upper Cambrian: Limestone near the ford on the

Cedartown road, 1.5 miles (2.4 km.) south of Rome, Floyd County, Ga. (Cooper Curtice, 1885).

Micromitra (Iphidella) pannula.
Obolus rotundatus.

96b.
Southern Railway, near Cave Spring, 10 miles
Curtice, 1885).
Obolus willisi.

96x. (lor stratigraphic position and association, see

(For stratigraphic position and association, see p. 147.)

Lingulella desiderata.

| *Lingulella leos.

Upper Cambrian: Shales in a railroad cut on the
(16.1 km.) southwest of Rome, Floyd: County, Ga. (Cooper

p. 147.) Middle Cambrian: Limestone 1 mile (1.6 km.)

‘ north of Adairsville, 15 miles (24.2 km.) northwest of Cartersville, Cartersville quadrangle (U. S. G. S.),

Bartow County, Ga. (Cooper Curtice, 1885).
*Acrotreta concentrica.

97 (=97x and $97x, though possibly from a slightly different horizon).

Upper Cambrian: ‘‘St. Croix sandstone”

at Reads Landing, foot of Lake Pepin, Wabasha County, Minn. (Cooper Curtice, 1884).

Obolus (Westonia) aurora.
Lingulella oweni.
Lingulella similis.
Dicellomus politus.

NN

97a. Upper Cambrian: ‘‘St. Croix sandstone
Lingulella similis.
Lingulella (Lingulepis) acuminata.
Billingsella coloradoensis.
EKoorthis remnicha.

”

97b. Upper Cambrian: In the “‘St. Croix sandstone”

Billingsella coloradoensis.
Koorthis sp.
*Syntrophia primordialis argia.

near Winfield, Jefferson County, Wis. (Cooper Curtice, 1884).

Hoorthis remnicha sulcata.
*Eoorthis remnicha winfieldensis.
Koorthis sp.

below the green-sand bed and about 25 feet (7.6 m.) above

St. Croix River, at Franconia, Chisago County, Minn. (Cooper Curtice, 1884).

Obolus matinalis.
Lingulella (Lingulepis) acuminata.
Billingsella coloradoensis.

97c. Upper Cambrian: “St. Croix sandstone” at Winfield, Jefferson County, Wis. (Cooper Curtice, 1884).

Lingulella similis.

97s. Upper Cambrian: “St. Croix sandstone” at Franconia, Chisago County, Minn. (Chas. Schuchert, 1893).

Lingulella similis.

97x (=97, though possibly from a slightly different horizon).

Eoorthis remnicha sulcata.

S97x (=97, though possibly from a slightly different horizon).

Dicellomus politus.
Billingsella coloradoensis.

98 (=98x, though from a slightly different horizon).
Eau Claire County, Wis. (Cooper Curtice, 1884).
Obolus matinalis.
*Obolus namouna.
*Obolus rhea.
Lingulella ampla.
Lingulella mosia osceola.

(Chas. Schuchert, 1893.)

(Chas. Schuchert, 1893.)

Upper Cambrian: “‘St. Croix sandstone” near Eau Claire

Lingulella phaon.

Lingulella (Lingulepis) acuminata.
Dicellomus politus.

Ptychoparia onustus (Whitfield).
Hyolithes.

220) CAMBRIAN BRACHIOPODA.

98a. Upper Cambrian: ‘‘St. Croix sandstone” at Marine Mills, on St. Croix River, Washington County, Minn.
Lingulella mosia. Ptychoparia sp.
Dicellomus politus. Ptychaspis granulosa (Owen).
Billingsella coloradoensis.

98x (=98, though from a slightly different horizon). (Cooper Curtice, 1884.)
Obolus matinalis. *Lingulella phaon.
Lingulella mosia. Dicellomus politus.

99. Upper Cambrian: ‘‘St. Croix sandstone” at Minneiska (Miniska), on Mississippi River, near the line between
Wabasha and Winona counties, Minn. (Cooper Curtice, 1884). j
Syntrophia primordialis.

992. Upper Cambrian: “‘St. Croix sandstone” near Pilot Knob, Adams County, Wis. (Cooper Curtice, 1884).
Lingulella mosia.
Lingulella (Lingulepis) acuminata.
Eoorthis remnicha winfieldensis.

100. Upper Cambrian: ‘‘St. Croix sandstone” near Menomonie, Dunn County, Wis. (Cooper Curtice, 1884).

Obolus matinalis. Lingulella winona convexa.
Obolus sp. undt. Dicellomus pectenoides.
Lingulella ampla. Dicellomus politus.
Lingulella mosia. Billingsella coloradoensis.

100a. Upper Cambrian: ‘‘St. Croix sandstone” at Ettrick, Trempealeau County, Wis. (Cooper Curtice, 1884).
Dicellomus politus.

101 (25 feet above 10la; same horizon as 102). (For stratigraphic position and association, see p. 147.) Middle
Cambrian: Rogersville shale just above the road in the hill west of the schoolhouse 3.5 miles (5.6 km.)
southwest of Rogersville, on the road to Melinda Ferry [see Keith, 1896a, areal geology sheet], Hawkins
County, Tenn. (R. R. Gurley, 1887).

Micromitra (Iphidella) pannula.
Obolus lamborni minimus.

101a (25 feet below 101). (For stratigraphic position and association, see p. 147.) Middle Cambrian: Rogersville
shale just above the road in the hill west of the schoolhouse 3.5 miles (5.6 km.) southwest of Rogersville, on
the road to Melinda Ferry [see Keith, 1896a, areal geology sheet], Hawkins County, Tenn. (R. R. Gurley,
1887).
*Obolus lamborni minimus.
Lingulella desiderata.
*Acrotreta rudis.

101b. (For stratigraphic position and association, see p. 147.) Middle Cambrian: Rogersville shale just east of
the schoolhouse 3.5 miles (5.6 km.) southwest of Rogersville, on the road to Melinda Ferry [see Keith, 1896a,
areal geology sheet], Hawkins County, Tenn. (R. R. Gurley, 1887).
Obolus lamborni.
Obolus willisi.
Lingulella desiderata.

102 (same horizon as101). (For stratigraphic position and association, see p. 147.) Middle Cambrian: Rogersville
shale just south of road 0.5 mile (0.8 km.) southwest of Rogersville, on the road to Melinda Ferry [see
Keith, 1896a, areal geology sheet], Hawkins County, Tenn. (R. R. Gurley, 1887).
Obolus lamborni.
Dicellomus appalachia.

102c. (For stratigraphic position and association, see p. 147.) Middle Cambrian: First shale south of the Estill-
ville pike, 3.5 miles (5.6 km.) east of Rogersville, Greeneville quadrangle (U.S. G. S.), Hawkins County,
Tenn. (R. R. Gurley, 1887).
Acrotreta rudis.

103 (below 103a). (For stratigraphic position and association, see p. 147.) Middle Cambrian: Second shale south
of the ridge of sandstone in the Rome formation (‘“Town Knobs”), on the road from Rogersville to Dodson
Ford, near the line between the Morristown and Greeneville quadrangles (U. S. G. S.), Hawkins County,
Tenn. (R. R. Gurley, 1887).
Obolus lamborni.

LOCALITIES. 221

103a (immediately underlying 103b). (For stratigraphic position and association, see p. 147.) Middle Cambrian:
Upper part of the second shale south of the ridge of sandstone in the Rome formation (‘‘Town Knobs’’),
on the road from Rogersville to Dodson Ford, near the line between the Morristown and Greeneville
quadrangles (U.S. G. S.), Hawkins County, Tenn. (R. R. Gurley, 1887).
Obolus lamborni minimus.
Dicellomus appalachia.

108b (immediately overlying 103a). (For stratigraphic position and association, see p. 147.) Middle Cambrian:

Third limestone (100 yards (90 m.) down the road toward the river from 103a) south of the ridge of sandstone

in the Rome formation (‘‘Town Knobs”’), on the road from Rogersville to Dodson Ford, near the line between

the Morristown and Greeneville quadrangles (U.S. G. S.), Hawkins County, Tenn. (R. R. Gurley, lee
Lingulella desiderata.

'

104. (For stratigraphic position and association, see p. 147.) Middle Cambrian: Shale in railroad cut 0.5 mile
(0.8 km.)from Rogersvilie, on the road to Holston River, near the line between the Morristown and Greene-
ville quadrangles (U.S. G. S.), Hawkins County, Tenn. (R. R. Gurley, 1887).
Dicellomus appalachia.

105. (For stratigraphic position and association, see p. 147.) Upper Cambrian: Limestone in Knox dolomite at
Bishops mill, Hancock County, Tenn. (Ira Sayles, 1884).
Lingulella (Lingulepis) acuminata.

105t. (For stratigraphic position and association, see p. 153.) Lower Ordovician: Thin-bedded bluish-gray lime-
stone [Walcott, 1908f, p.173, aud Pls. XIII and XIV], at the summit of Notch Peak, House Range, Millard
County, Utah (C. D. Walcott, F. B. Weeks, and L. D. Se 1905).
*Obolus (Westonia) notchensis.
Eoorthis desmopleura.
Raphistoma sp.

105x. (Forstratigraphic position and association, seep. 148.) Middle Ordovician: Gray siliceous shales just below
a band of quartzitic sandstones probably corresponding in position to the upper part of the Simpson forma-
tion of the Oklahoma section, in Wasatch Canyon, east of Lakeview ranch, about 5 miles (8 km.) north of
Brigham, Boxelder County, Utah (F. B. Weeks and L. D. Burling, 1905).
*Obolus (Westonia) elongatus.

106. (For stratigraphic position and association, see p. 147.) Middle Cambrian: Shales of the Rome formation on
the roadside at the eastern base of Shooks Gap, in Bays Mountains, 10 miles (16.1 km.) southeast of Knoxville
[see Keith, 1895, areal geology sheet], Knox County, Tenn. (Cooper Curtice, 1885).
Lingulella similis.

106a. (For stratigraphic position and association, see p. 147.) Middle Cambrian: Reddish-brown shales in middle
of valley east of Shooks Ridge, in Bays Mountains, 10 miles (16.1 km.) southeast of Knoxville, Knox County,
Tenn. (Cooper Curtice, 1885).
Obolus willisi.

107 (just above 107a). (For stratigraphic position and association, see p. 147.) Middle Cambrian: Limestone in
Bull Run, northwest of Copper Ridge [Keith, 1896b, areal geology sheet], 11 miles (17.6 km.) northwest of
Knoxville, Knox County, Tenn. (Cooper Curtice, 1885).

Dicellomus appalachia.
Wimanella harlanensis.

107a (just below 107, above 107b). (For stratigraphic position and association, see p. 147.) Middle Cambrian:
Shales in railroad cut in Bull Run, northwest of Copper Ridge [Keith, 1896b, areal geology sheet], 11 miles
(17.6 km.) northwest of Knoxville, Knox County, Tenn. (Cooper Curtice, 1885).
Obolus willisi.
Lingulella desiderata ?.

107b (below 107a). (For stratigraphic position and association, see p. 147.) Middle Cambrian: Shales and sand-
stones of the Rome formation in railroad cut in Bull Run, northwest of Copper Ridge [Keith, 1896b, areal
geology sheet], 11 miles (17.6 km.) northwest of Knoxville, Knox County, Tenn. (Cooper Curtice, 1885).
Obolus willisi. Dicellomus appalachia.
Lingulella?. Linnarssonella tennesseensis.

222 CAMBRIAN BRACHIOPODA.

1070 (just above 107u). (Forstratigraphic position and association, see p. 147.) Upper Cambrian: Limestones and
shales at the base of the Knox dolomite west of the top of Copper Ridge, near the Southern Railway cut.
about 10 miles (16.1 km.) northwest of Knoxville [see Keith, 1896b, areal geology sheet], Knox County, Tenn,

; (Cooper Curtice, 1885).
Lingulella desiderata.
Lingulella (Lingulepis) acuminata.
Acrotreta kutorgai.

107u (just below 1070). (For stratigraphic position and association, see p. 147.) Upper Cambrian: Limestones and
shales at the base of the Knox dolomite west of the top of Copper Ridge, near the Southern Railway cut,
about 10 miles (16.1 km.) northwest of Knoxville [see Keith, 1896b, areal geology sheet], Knox County, Tenn.
(Cooper Curtice, 1885). :
Lingulella desiderata?. 5
Acrotreta kutorgai.

108. Upper Cambrian: Sandstone 1 mile (1.6 km.) south of Poughkeepsie, Dutchess County, N. Y. (C. D. Walcott,
1886).
Lingulella (Lingulepis) acuminata.

109 (see 367k). Upper Cambrian: Sandstone 25 feet (7.6 m.) above the Archean 1.5 miles (2.4 km.) south cf
Deweys Bridge, on the Champlain Canal, Washington County, N. Y. (C. D. Walcott, 1886).
Lingulella (Lingulepis) acuminata. :

110 (just below 110a). Upper Cambrian: Shaly calcareous sandstone resting on massive layers of Potsdam sand-
stone, east side of the town of Whitehall, Washington County, N. Y. (C. D. Walcott, 1886).
Lingulella (Lingulepis) acuminata.

110a (just above 110). Upper Cambrian: Sandstone on the east side of the town of Whitehall, Washington County,
N. Y. (C. D. Walcott, 1886).
Lingulella (Lingulepis) acuminata.

111. Upper Cambrian: At the top of the Potsdam sandstone on Marble River, 1 mile (1.6 km.) south of Chateaugay,.
Franklin County, N. Y. (C. D. Walcott, 1886).
Lingulella (Lingulepis) acuminata.
113. Upper Cambrian: “‘St. Croix sandstone” at La Grange Mountain (or Barn Bluff), near Red Wing, Goodhue
County, Minn. (Cooper Curtice, 1884).
Lingulella mosia.
Lingulella winona.

114 (above 114a). (For stratigraphic position and association, see p. 140.) Upper Cambrian: Upper sandstone
beds on Little Belle Island, Conception Bay, Newfoundland (C. D. Walcott, 1888).
Lingulella bella.
Lingulella bellula.

114a (below 114). (For stratigraphic position and association, see p. 140.) Upper Cambrian: Sandy shales under-
lying beds of Locality 114, Little Belle Island, Conception Bay, Newfoundland (C. D. Walcott, 1888).
Lingulella bella.
*Lingulella bellula.

114b. (For stratigraphic position and association, see p. 140.) Lower Ordovician: Sandstone 1 mile (1.6 km.)
north of Lance Cove, Great Belle Island, Conception Bay, Newfoundland (C. D. Walcott, 1888).
*Obolus (Lingulobolus) affinis. Obolus (Westonia) rogersi.
*Obolus (Lingulobolus) spissus. *Lingulella bella.

116. Upper Cambrian: ‘‘St. Croix sandstone” in excavation on Wells farm, 2 miles (3.2 km.) west of Baraboo,.
Baraboo quadrangle (U.S. G. S.), Sauk County, Wis.
*Billingsella major.

117. (For stratigraphic position and association, see p. 147.) Middle Cambrian: Shales on the road north from
Greeneville, Greene County, Tenn. (Cooper Curtice, 1886).
Lingulella desiderata.

11%e. (For stratigraphic position and association, see p. 147.) Middle Cambrian: Shale at Buckingham Ford on
Hollis Creek, 5 miles (8 km.) southeast of Greeneville, Greene County, Tenn. (Cooper Curtice, 1886).
Dicellomus appalachia.

LOCALITIES. | 223

118 (same horizon as 117c). (For stratigraphic position and association, see p. 147.) Middle Cambrian: Shales on
the Tazewell road, 2 miles (3.2 km.) north of Knoxville, Knox County, Tenn. (M. R. Campbell, 1891).
Obolus lamborni minimus.

119. (For stratigraphic position and association, see p. 147.) Middle Cambrian: Limestone in various localities
in Jefferson and Hawkins counties, Tenn. (Iva Sayles, 1885).
Dicellomus appalachia.

121. (For stratigraphic position and association, see p. 147.) Middle Cambrian: Rogersville shale, road just east
of Harlan Knob, 4 miles (6.4 km.) northeast of Rogersville [see Keith, 1905, areal geology sheet], Hawkins
County, Tenn. (C. D. Walcott, 1891).

Micromitra alabamaensis. Acrotreta rudis.
Obolus lamborni. *Billingsella? appalachia.
Obolus willisi. *Wimanella harlanensis.

Lingulella desiderata.

121a (For stratigraphic position and association, see p. 147.) Middle Cambrian: Shales on road leading from
southeast of Harlan Knob to Amis post office, about 4 miles (6.4 km.) northeast of Rogersville [see Keith,
1905, areal geology sheet], Hawkins County, Tenn. (C. D. Walcott, 1891).
Micromitra alabamaensis.

122. (For stratigraphic position and association, see p. 147.) Upper Cambrian: Shale southwest of ‘‘Town
Knobs’’,2 1 mile (1.6 km.) southwest of Rogersville, Hawkins County, Tenn. (C. D. Walcott, 1891).
Obolus willisi.
Lingulella desiderata.

122a. (or stratigraphic position and association, see p. 147.) Upper Cambrian: Shale at the headwaters of For-
gey Creek, northwestern part of the Greeneville quadrangle (U.S. G.S.), Hawkins County, Tenn. (C. D.
Walcott, 1891).
Obolus lamborni.
Lingulella desiderata.

128. (For stratigraphic position and association, see p. 147.) Middle Cambrian: Upper part of Maryville lime-
stone on Big Creek, southeast of Harlan Knob, 4 miles (6.4 km.) northeast of Rogersville [see Keith, 1905,
p. 4, and areal geology sheet], Hawkins County, Tenn. (C. D. Walcott, 1891).
Micromitra alabamaensis.
Ptychoparia.

124 (=124a). (For stratigraphic position and association, see p. 147.) Middle Cambrian: Shales (Nolichucky?)
overlying the limestone which rests on the Rogersville shale on Big Creek, southeast of Harlan Knob, 4
miles (6.4 km.) northeast of Rogersville [see Keith, 1905, p. 4, and areal geology sheet], Hawkins County,
Tenn. (C. D. Walcott, 1891).

Micromitra alabamaensis.
Obolus lamborni minimus.

124a (=124). (For stratigraphic position and association, see p. 147.) (C. D. Walcott, 1891.)
Obolus lamborni.
Lingulella (Lingulepis) acuminata.
Dicellomus appalachia.

128. (For stratigraphic position and association, see p. 147.) Upper Cambrian: Shale 1.5 miles (2.4 km.) south-
west of Cleveland, Bradley County, Tenn. (C. D. Walcott, 1891).
Lingulella?.

128a. (For stratigraphic position and association, see p. 147.) Upper Cambrian: Shales on the Louisville and
Nashville Railroad, 1.5 miles (2.4 km.) southeast of Cog Hill, near the line between Polk and McMinn
counties, Tenn. (M. R. Campbell, 1891). ;
Lingulella sp.
Dicellomus politus.

131. Upper Cambrian: Sandstone in a cut on the Chicago, Milwaukee and St. Paul Railway, 4 miles (6.4 km.)
southeast of Lake City, Wabasha County, Minn. (C. Schuchert, 1893).
Billingsella coloradoensis.

134. Upper Cambrian: “‘St. Croix sandstone” in the lowest beds exposed along the banks of Red Cedar River,
opposite Menomonie, Dunn County, Wis. (C. Schuchert, 1893).
Obolus matinalis.

a See localities 103, 103a, and 103b, pp. 220-221.

224 CAMBRIAN BRACHIOPODA.

134a. Upper Cambrian: ‘‘St. Croix sandstone” in a quarry 1 mile (1.6 km.) southeast of the county courthouse,
in Menomonie, Dunn County, Wis. (C. Schuchert, 1893).
Syntrophia barabuensis.

135. Upper Cambrian: ‘‘St. Croix sandstone” near Trempealeau, Trempealeau County, Wis. (C. Schuchert,
1893).
Lingulella winona convexa.

135b. Upper Cambrian: ‘‘St. Croix sandstone’’ near Trempealeau, Trempealeau County, Wis. (C.Schuchert,
1893).
Finkelnburgia finkelnburgi.

135¢ (=83'). Upper Cambrian: Uppermost horizon of the “St. Croix sandstone” near Trempealeau, Trem-
pealeau County, Wis. (C. Schuchert, 1893).
Finkelnburgia finkelnburgi.
Finkelnburgia osceola.
Dikellocephalus minnesotensis Owen.

136. Upper Cambrian: Potsdam sandstone in bank of stream opposite the first switch on the Port Henry and Maine
Railroad out of Port Henry, Essex County, N. Y. (C. D. Walcott, 1889).
Lingulella prima.

137. (For stratigraphic position and association, see p. 147.) Middle Cambrian: Shales on southeast side of north-
east end of Cane Creek Mountains, 3 miles (4.8 km.) south of Gadsden, Etowah County, Ala. (Cooper Curtice,
1892).
Acrotreta kutorgai.

138. (For stratigraphic position and association, see p. 147.) Middle Cambrian: Shale in the street northeast of
Printuf House, Gadsden, Etowah County, Ala. (Cooper Curtice, 1892).
Lingulella similis.

138a. (For stratigraphic position and association, see p. 147.) Middle Cambrian: Shales in the Rome formation
west of the cemetery west of Rome, Floyd County, Ga. (Cooper Curtice, 1892).
Lingulella similis.

139. (For stratigraphic position and association, see p. 147.) Middle Cambrian: Limestone on Hokes Bluff road
north of the chert outcrop, 5 miles (8 km.) east of Gadsden, Etowah County, Ala. (Cooper Curtice, 1892).
Lingulella desiderata.

139a. (For stratigraphic position and association, see p. 147.) Middle Cambrian: Limestone on road near Wades
Gap, near Chepultepec, Jefferson County, Ala. (Cooper Curtice, 1892).
Acrotreta kutorgai.

140. (For stratigraphic position and association, see p. 147.) Middle Cambrian: Limestone interbedded in shales
near Chepultepec, Jefferson County, Ala. (Cooper Curtice, 1892).
Acrotreta kutorgai.

140a. (For stratigraphic position and association, see p. 147.) Middle Cambrian: Shales 200 yards (182.9 m.) east
of Thomas Mills, 5 miles (8 km.) north of Cave Spring [see Hayes, 1902, historical geology sheet], Floyd
County, Ga. (Cooper Curtice, 1892).
Obolus lamborni. :
Obolus willisi.
Lingulella quadrilateralis.

140c. (For stratigraphic position and association, see p. 147.) Middle Cambrian: Shale at edge of hill on the road
leading west of Cave Spring, 10 miles (16.1 km.) southwest of Rome, Floyd County, Ga. (Cooper Curtice,
1892).
Lingulella similis.
Lingulella sp.

141a. (For stratigraphic position and association, see p. 147.) Middle Cambrian: Limestone 0.25 mile (0.4 km.)
west of the hotel at Montevallo, Shelby County, Ala. (Cooper Curtice, 1892).
Obolus (Westonia) ella.

142. (For stratigraphic position and association, see p. 147.) Middle Cambrian: Shales just above the Olenellus
zone near the railroad 4.5 miles (7.2 km.) north of Montevallo, Shelby County, Ala. (Cooper Curtice, 1892).
Acrotreta kutorgai?.

LOCALITIES. 225

144c. (For stratigraphic position and association, see p. 147.) Middle Cambrian: Limestone near the top of the
beds exposed near N. K. Burns’s barns, near Viola, Blount County, Ala. (Cooper Curtice, 1892).
Dicellomus appalachia.

145. (For stratigraphic position and association, see p. 147.) Middle Cambrian: Shale in bluff on Coosa River east
of Turkeytown, 8 miles (12.8 km.) northeast of Gadsden, Etowah County, Ala. (Biddle and Russell, 1886).
Lingulella similis.

146. (For stratigraphic position and association, see p. 147.) Middle Cambrian: Conasauga (‘‘Coosa”’) shale on
the Jacksonville road, 8 miles (12.8 km.) east of Center, Cherokee County, Ala. (Biddle, 1885).
Obolus willisi.

147a. Upper Cambrian: Limestone in Spring Hill Canyon, west side of the Bridger Range, Gallatin County, Mont.
(A. C. Peale, 1885).

Billingsella coloradoensis.

-148a. Upper Cambrian: Limestone of the Gallatin formation at the head of Bostwick Canyon (the name is given
on the Threeforks sheet (U. S. G. S.)) [Iddings and Weed, 1894, areal geology sheet 2], in the Bridger Range,
: Livingston quadrangle (U.S. G. S.), Gallatin County, Mont. (A. C. Peale, 1885).
Obolus tetonensis.

149a. Middle Cambrian: Limestone at the forks of Pole Creek, above Cherry Creek basin, Threeforks quadrangle
(U.S. G. S.), Madison County, Mont. (A. C. Peale, 1887).
Micromitra (Iphidella) pannula.
*Billingsella striata.

150a. Upper Cambrian: Limestone on the east side of Dry Creek, above the mouth of Pass Creek, about 5 miles

(8 km.) north of Hillsdale, Threeforks quadrangle (U.S.G.S.), Gallatin County, Mont. (A.C. Peale, 1885).
Billingsella plicatella.
Eoorthis wichitaensis.

151 (see 151a). Upper Cambrian: Limestone in point overlooking Churn Canyon, on the west side of the Bridger
Range, Gallatin County, Mont. (A. C. Peale, 1885).
Obolus discoideus.
Billingsella plicatella.
Eoorthis wichitaensis.

151a (a little higher horizon than 151, same locality). Upper Cambrian: Limestone in point overlooking Churn
Canyon, on the west side of the Bridger Range, Gallatin County, Mont. (A. C. Peale, 1885).
Dicellomus pectenoides.
Billingsella plicatella.

152. Upper Cambrian: Limestone on ridge between Churn and Cottonwood canyons, west side of Bridger Range,
Gallatin County, Mont. (A. C. Peale, 1885).
Billingsella plicatella.
Eoorthis desmopleura?.

152a. Upper Cambrian: Limestone on west side of Dry Creek, below Pass Creek, Threeforks quadrangle (U.S.
G. S.), Gallatin County, Mont. (A. C. Peale, 1885).
Dicellomus nanus.

152b. Upper Cambrian: East side of Dry Creek, below Pass Creek, Threeforks quadrangle (U. 8. G. S.),
Gallatin County, Mont. (A. C. Peale, 1885).
Obolus tetonensis?.

158 (slightly different horizon than 1532). Upper Cambrian: Limestone in ravine on west side of Dry Creek, near
the mouth of Pass Creek, about 5 miles (8 km.) north of Hillsdale, Threeforks quadrangle (U. S..G. S.),
Gallatin County, Mont. (A. C. Peale, 1885).
Billingsella plicatella.
Huenella abnormis.

158a (slightly different horizon than 153). Upper Cambrian: Limestone in ravine on west side of Dry Creek, near
the mouth of Pass Creek, about 5 miles (8 km.) north of Hillsdale, Threeforks quadrangle (U.8.G.S8.),
Gallatin County, Mont. (A. C. Peale, 1885).
Eoorthis remnicha.
Eoorthis remnicha texana.
Eoorthis wichitaensis.

aTddings, J. P.,and Weed, W. H., Livingston folio (No. 1), Geol. Atlas U. S., U. S. Geol. Survey, 1894.
62667°—vot 51, pr 1—12 15

<

’

226 CAMBRIAN BRACHIOPODA. :
154. Upper Cambrian: Limestone in hill on west side of Dry Creek, opposite mouth of Pass Creek, about 5 miles
(8 km.) north of Hillsdale, Threeforks quadrangle (U.S.G.S.), Gallatin County, Mont. (A. C. Peale, 1885).
Billingsella plicatella. F
EKoorthis desmopleura?.
Eoorthis remnicha.

155. Upper Cambrian: Limestone north of East Gallatin River, near Hillsdale, Threeforks quadrangle (U. S.
G.S.), Gallatin County, Mont. (A. C. Peale, 1888).
Billingsella coloradoensis.

155a. Middle Cambrian: Limestone north of East Gallatin River, near Hillsdale, Threeforks quedrangle (U.S.
G.S.), Gallatin County, Mont. (A. C. Peale, 1888).
*Micromitra pealei.

156a. Middle Cambrian: Limestones of the Flathead formation [Peale, 1893, p. 20], north of East Gallatin
River, near Hillsdale, Gallatin County, Mont. (A. C. Peale. 1888).
Acrotreta attenuata.

156b. Upper Cambrian: Limestone north of East Gallatin River, at the north end of the Gallatin Valley,
Threeforks quadrangle (U.S. G. §.), Gallatin County, Mont. (A. C. Peale, 1884).
Billingsella plicatella.

157 (same locality as 158 and 156, but different horizon). Upper Cambrian: Limestone north of East Gallatin
River, near Hillsdale, Threeforks quadrangle (U.S. G. S.), Gallatin County, Mont. (A. C. Peale, 1888).
Billingsella plicatella. ;
Huenella abnormis.

158 (same locality as 156, 157, and 158a, but different horizon). Upper Cambrian: Limestone north of East
Gallatin River, near Hillsdale, Threeforks quadrangle (U. 8. G. S.), Gallatin County, Mont. (A. C.
Peale, 1889).
Dicellomus pectenoides. Eoorthis desmopleura.
*Billingsella plicatella. Huenella abnormis.

158a (same locality as 156. 157, and 158, but different horizon). Upper Cambrian: Limestone north of Hast
Gallatin River, near Hillsdale, Threeforks quadrangle (U. S. G. S.), Gallatin County, Mont. (A. C.
Peale, 1889). 4
Dicellomus nanus.

159. Middle Cambrian: Limestones north of West Gallatin (Gallatin) River, Gallatin County, Mont. (A. C.
Peale, 1884).
Micromitra pealei. ~
Obolus rotundatus.
Acrotreta attenuata.

Billingsella coloradoensis.
Olenoides?.

160. Upper Cambrian: Sandstones forming a remnant of the Gallatin formation which lies between the exposures
of ‘‘porphyrite” on the east side of Willow Creek [Peale, 1896, areal geology sheet], 12 miles (19.2 km.)
south-southwest of Threeforks, Threeforks quadrangle (U. S. G. S.), Gallatin County, Mont. (A. C.
Peale, 1889).

Micromitra (Paterina) superba?.

160a. Upper Cambrian: Sandstone west of Bear Creek, south of the Gallatin Va.ley southwest of Bozeman,
Threeforks quadrangle (U. 8. G. 8.), Gallatin County, Mont. (A. C. Peale, 1889).
Obolus rotundatus.

161. Upper Cambrian: Limestone on the south side of West Gallatin (Gallatin) River, northwest of Hamilton
on the north side of the Gallatin Valley, Gallatin County, Mont. (A. C. Peale, 1884).
Obolus tetonensis. ‘
Lingulella desiderata.

168 (=55c). (For stratigraphic position and association, see p. 152.) (R.S. Spence.,
Micromitra (Iphidella) pannula. *Nisusia (Jamesella) nautes.
Acrothele subsidua. *Nisusia (Jamesella) spencei.
*Acrotreta definita.

164. Middle Cambrian: Sandstone in the Deadwood formation in the cliffs on the east side of the valley near
Deadwood, Black Hills, South Dakota.
Dicellomus pectenoides.

164f. (For stratigraphic position and association, see p. 147.) Middle Cambrian: Shales just above a bed of
limestone on the road leading northwest out of Montevallo, Shelby County, Ala.
Obolus? sp.

LOCALITIES. 227

165. Middle Cambrian: Limestone on the east side of the valley, in railroad cut about 1 mile (1.6 km.) below
the main part of Deadwood, Black Hills, South Dakota.
Lingulella similis.
Acrotreta idahoensis.
Linnarssonella girtyi.

167. Middle Cambrian: Sandstone beneath limestone and resting on pre-Cambrian “‘slates, schists, and peg-
matites” in bluff 9 miles (14.4 km.) west of Custer, Black Hills, South Dakota.
Lingulella cuneola?.
Lingulella (Lingulepis) acuminata.
Dicellomus politus.

168. Upper Cambrian: Limestones on north side of Tepee Creek, near the road from Sheridan to Dome Lake,
Bighorn Mountains, Sheridan County, Wyo. (C. D. Walcott).
Eoorthis desmopleura. Eoorthis remnicha.
*Boorthis desmopleura nympha. Syntrophia primordialis.

170. Middle Cambrian: Sandstone about 10 miles (16.1 km.) south-southeast of Bald Mountain, Bighorn Moun-
tains, Wyo.
Obolus matinalis.
Dicellomus nanus.

1
171 (200 feet below 171la). Middle Cambrian: Sandstone in Big Goose Creek Canyon, in the Bighorn Mountains,
west of Sheridan, Sheridan County, Wyo.
Lingulella (Lingulepis) acuminata (ranging through 200 feet of beds).

171a (200 feet above 171). Middle Cambrian: Sandstone in Big Goose Creek Canyon, in the Bighorn Mountains,
west of Sheridan, Sheridan County, Wyo.
Obolus (Westonia) ella.
Lingulella (Lingulepis) acuminata.

174c. (For stratigraphic position and association, see p. 138.) Lower Cambrian: Sandstones on small hill in
the salt flat 1 mile (1.6 km.) northeast of Silver Peak mill, Silver Peak quadrangle (U.S. G. S.), Esme-
ralda County, Nev. (C. D. Walcott and F. B. Weeks, 1896).
*Mickwitzia occidens.
Obolus?.
Obolella sp.

175. (For stratigraphic position and association, see p. 138.) Lower Cambrian: Shales carrying Olenellus on
the divide between Clayton and Fish Lake valleys, about 15 miles (24.2 km.) south-southwest of the town
of Silver Peak, Silver Peak quadrangle (U. S. G. S.), Esmeralda County, Nev. (C. D. Walcott and F. B.
Weeks, 1896).
Obolus?.
Kutorgina perugata?.

*Acrotreta claytoni.
Swantonia? sp.

176. (For stratigraphic position and association, see p. 138.) Lower Cambrian: Shales and interbedded lime-
stones between massive limestone containing Archxocyathus, at the south end of Deep Spring Valley,
Inyo County, Cal. (C. D. Walcott and F. B. Weeks, 1896).
Obolella vermilionensis. Wanneria gracile Walcott.
Obolella? sp. Olenellus fremonti Walcott.
Trematobolus excelsis.

176a. (For stratigraphic position and association, seep. 138.) Lower Cambrian: Sandstone on ridge east of the
head of Mazouka Canyon, Inyo Range, Inyo County, Cal. (C. D. Walcott, 1897).
Trematobolus excelsis.

178a (slightly higher than 176, but same locality). (For stratigraphic position and association, see p. 138.) (C.D.
Walcott and F. B. Weeks, 1896.) é
Trematobolus excelsis. Wanneria gracile Walcott.
Billingsella highlandensis?. Olenellus fremonti Walcott.

184. (For stratigraphic position and association, see p. 138.) Lower Cambrian: Shales at the summit of the
Silver Peak Range, 10 miles (16.1 km.) southwest of the town of Silver Peak, Silver Peak quadrangle
(U.S. G.S.), Esmeralda County, Nev. (C. D. Walcott, 1896).
Kutorgina perugata.
Acrotreta claytoni.

228 CAMBRIAN BRACHIOPODA.

185. Upper Cambrian: Sandy layers above the massive Potsdam sandstone 0.5 mile (0.8 km.) southeast of
Redwood, Jefferson County, N. Y. (C. D. Walcott, 1886).
Lingulella (Lingulepis) acuminata.

185a. Upper Cambrian: Sandy layers 20 feet (6 m.) above the massive Potsdam sandstone, east side of Indian
View, 3 miles (4.8 km.) south of Theresa, Jefferson County, N. Y. (C. D. Walcott, 1886).
Lingulella (Lingulepis) acuminata.

185z. (For stratigraphic position and association, see p. 148.) Lower Ordovician: Limestones at the base of the
Lower Ordovician [Walcott, 1908f, p. 191], in Blacksmith Fork Canyon, about 9 miles (14.4 km.) east of
Hyrum, Cache County, Utah (C. D. Walcott and L. D. Burling, 1906).

Obolus discoideus. Orthoceras.
EKoorthis desmopleura. Endoceras.
Syntrophia nundina. Fragments of trilobites.

186. Lower Ordovician: Near line of contact between red and gray Ordovician limestone, in red siliceous lime-
stone about 30 feet (9.1 m.) above the pre-Cambrian rocks, Williams Canyon, Manitou, El Paso County,
Colo. (C. D. Walcott, 1890).
Lingulella desiderata.
Schizambon manitouensis.
Koorthis desmopleura.

HKoorthis desmopleura nympha.
Syntrophia nundina.

186a (slightly higher horizon than 186). Lower Ordovician: Near line of contact between red and gray Ordovician
limestone, in siliceous red limestone about 35 feet (10.7 m.) above the pre-Cambrian rocks, Williams Canyon,
Manitou, El] Paso County, Colo. (T. W Stanton, 1890).
*Schizambon manitouensis.
Koorthis desmopleura.
Syntrophia nundina.

187. Lower Ordovician: Red siliceous limestone 105 to 122 feet (32 to 36.7 m.) above the pre-Cambrian rocks,
2 miles (3.2 km.) below Manitou Park Hotel, El Paso County, Colo. (Whitman Cross, 1882).
Lingulella desiderata.
Eoorthis desmopleura.

201. (For stratigraphic position and association, see p. 139.) Passage beds between the Upper Cambrian and the
Ordovician: Arenaceous Pogonip limestone on east slope of ridge east of Hamburg Ridge Eureka district
[Hague, 1892, Atlas], Eureka County, Nev. (Arnold Hague and ©. D. Walcott, 1880).
*Lingulella pogonipensis.
Acrotreta idahoensis alta.
.Hoorthis hamburgensis.

201a. (For stratigraphic position and association, see p. 139.) Lower Ordovician: Pogonip limestone, east slope
of the ridge east of Hamburg Ridge, Eureka district [Hague, 1892, Atlas], Eureka County, Nev. (C. D.
Walcott, 1882). '

*Obolus (Westonia) iphis. Acrotreta idahoensis.

Lingulella pogonipensis. Eoorthis hamburgensis.

*Schizambon typicalis. Syntrophia nundina.

Acrothele sp. Agnostus prolongus Hall and Whitfield.

202. (For stratigraphic position and association, see p. 139.) Lower Ordovician: Pogonip limestone on the summit
of the ridge directly southeast of the Jackson mine, northwest of Shadow Canyon, Eureka district [Hague,
1892, Atlas], Eureka County, Nev. (C. D. Walcott, 1880).
Lingulella manticula. Elkania ambigua.
Lingulella sp. Acrotreta idahoensis.

203. (For stratigraphic position and association, see p. 139.) Lower Ordovician: Pogonip limestone on spur of
Hamburg Ridge extending out southwest from Wood Cone, Eureka district [Hague, 1892, Atlas], Hureka
County, Nev. (C. D. Walcott, 1880).
Syntrophia nundina.
Bathyurus congeneris Walcott.
Bathyurus tuberculatus Walcott.

203a. (For stratigraphic position and association, see p. 139.) Passage beds between the Upper Cambrian and
the Ordovician: Limestones at base of Pogonip limestone in the spur of Hamburg Ridge extending out
southwest from Wood Cone, Eureka district [Hague, 1892, Atlas], Eureka County, Nev. (C. D. Walcott, 1880).
Lingulella pogonipensis.
*Acrotreta curvata.
Agnostus tumidosus Hall and Whitfield.

LOCALITIES. 229

204. (For stratigraphic position and association, see p. 139.) Lower Ordovician: Pogonip limestone on the
lower part of the eastern slope of the ridge east of Hamburg Ridge, facing Secret Canyon road, Eureka dis-
trict [Hague, 1892, Atlas], Eureka County, Nev. (C. D. Walcott, 1880).
*Syntrophia nundina. 5

205. (For stratigraphic position and association, see p. 139.) Passage beds between the Upper Cambrian and the
Ordovician: Siliceous limestone on Roundtop Mountain, Eureka district [Hague, 1892, Atlas], Eureka
County, Nev. (Arnold Hague and J. P. Iddings, 1880).
Obolus mera. *Acrotreta? cancellata.
*Obolus (Westonia) sp. undt. b. Koorthis hamburgensis.
Lingulella pogonipensis.

206a. (For stratigraphic position and association, see p. 139.) Passage beds between the Upper Cambrian and the
Ordovician: Sandy limestone on Hoosac Mountain, Eureka district [Hague, 1892, Atlas], Eureka County,
Ney. (C. D. Walcott, 1880).
Acrotreta idahoensis alta.

209. (For stratigraphic position and association, see p. 139.) Lower Ordovician: Pogonip limestone on the
west side of Goodwin Canyon, Eureka district [Hague, 1892, Atlas], Eureka County, Nev. (C. D. Walcott,
1880).
Syntrophia nundina.

211. (For stratigraphic position and association, see p. 139.) Passage beds between the Upper Cambrian and the
Ordovician: Siliceous Pogonip limestone on spur of Hamburg Ridge extending southwest from Wood Cone,
Eureka district [Hague, 1892, Atlas], Eureka County, Nev. (Arnold Hague, J. P. Iddings, and C. D. Walcott,
1880).
Lingulella pogonipensis.

214a (see 313k). (Forstratigraphic position and association, see p. 139.) Ordovician: Near the base of the Pogonip
limestone, White Pine district, White Pine County, Nev. (C. D. Walcott and C. H. H., 1882).
*Obolus sp. undt. c.

214b (see 313k). (Forstratigraphic position and association, see p. 139.) Lower Ordovician: Limestones near the
middle of the Pogonip limestone, White Pine district, White Pine County, Nev. (C. D. Walcott and C. H. H.,
> 1882).
Lingulella manticula.

216a. Ordovician: Limestone at Fossil Butte, 10 miles north of Hyko, Lincoln County, Nev. (C. D. Walcott,
1885).
Huenella sp.

220a. Ordovician: Shales of the ‘‘Upper Sillery”’ (Lauzon of Logan) on Chaudiere River, at the Grand Trunk
Railroad bridge, Province of Quebec, Canada (C. D. Walcott, 1889).
*Linculella ellsi.
*Acrothele pretiosa.

221. (For stratigraphic position and association, see p. 139.) Ordovician: Pogonip limestone, below the white
quartzite, at the western base of Lone Mountain, Keyes Valley, 18 miles (28.8 km.) northwest of Eureka,
Eureka County, Nev. (C. D. Walcott, 1880).
Acrotreta sp. undt.

227. Lower Ordovician: Limestone near Fort Cassin, Addison County, Vt. (W. P. Rust, 1887).
*Syntrophia lateralis.
Localities 8300-3962, arbitrarily numbered.2

300 [Matthew, 1886, p.37]. (For stratigraphic position and association, see p. 132.) Middle Cambrian: Shaly sand-

stones, possibly of Division 1d of Matthew, on Long Reach, St. John River, Kings County, New Brunswick.
*Acrotreta baileyi Matthew.
Ptychoparia robbi ? (Hartt).

801 (references follow species; see 2h). (For stratigraphic position and association, see p. 133.) Middle Cambrian:
In sandstones of Division 1b2 of the ‘‘ Protolenus zone” [Matthew, 1895a, p. 108], on Hanford Brook, St.
John County, New Brunswick.

Acrothele matthewi lata [Matthew, 1886, p. 42]. *Trematobolus pristinus [Matthew, 1895a, p. 122].
Acrotreta baileyi? [Matthew, 1886, p. 37]. *Beyrichona papilio [Matthew, 1886, p. 66].
Acrotreta gemmula [Matthew, 1895a, p. 126]. *Beyrichona tinea [Matthew, 1886, p. 66].

*Trematobolus insignis [Matthew, 1895a, p. 123].

@ See the explanatory paragraphs on pp. 160-161.

230

801a (references follow species). (For stratigraphic pos
grained sandstones below the Protolenus-bearing
Brook, St. John County, New Brunswick.
*Acrothele matthewi lata [Matthew, 1895a, Pl. V, fig. 8].
Acrothele matthewi prima [Matthew, 1895a, Pl. V, fig. 7].
*Acrotreta gemmula [Matthew, 1894, p. 88].

301b [Matthew, 1895a, p. 126].

_CAMBRIAN BRACHIOPODA.

ition and association, see p. 132.) Middle Cambrian: Fine-
shales and sandstones in Division 1b3 of Matthew, Hanford

*Diplotheca acadica crassa [Matthew, 1886, p. 55].
*Diplotheca hyattiana [Matthew, 1886, p. 52].
*Acraulos? articephalus [Matthew. 1886, p. 75].

(For stratigraphic position and association, see p. 132.) Middle Cambrian: Sand

stones of Division 1b5 and higher of the “‘Protolenus zone” [Matthew, 1895a, p. 108], Hanford Brook,

St. John County, New Brunswick.
Acrotreta sagittalis transversa.

801¢ [Walcott, 1884a, p. 16].

(Por stratigraphic position and association, see p. 132.)

Middle Cambrian: Sand-

stones of the St. John formation at Coldbrook, St. John County, New Brunswick.

*Acrotreta sagittalis transversa.
Aciotreta sp.

301d (Matthew, 1895a, p. 128].

(For stratigraphic position and association, see p. 132.) Middle Cambrian: Sand-

stones of Division 1b5 of Matthew, on Hanford Brook, St. John County New Brunswick.

Acrothele prima costata.

801e [Matthew, 1903, p. 204].
C3a of Matthew, in the St. John Basin, St. John
_ Lingulella ef. lepis.

801i [Matthew, 1905a, p. 128].
stones of Division 1b5 of the “‘ Protolenus zone
River, Kings County, New Brunswick.
Acrothele prima costata.

301g (references follow species; see 301lw, 308h, and 3081).

(For stratigraphic posit

(For stratigraphic position and association, see p. 131.) Upper Cambrian: In Division

County, New Brunswick.

ion and association, see p. 132.) Middle Cambrian; Sand-
” of Matthew, at Catons Island, in Long Reach, St. John.

(For stratigraphic position and association, see p. 132.)

Middle Cambrian: Sandstones of Division le of Matthew, at Portland (now part of the city of St. John),

St. John County, New Brunswick.

Lingulella dawsoni [Matthew, 1886, p. 34]=Lingulella
ferruginea.

Acrothele matthewi [Matthew, 1886, p. 41].

Acrothele matthewi Jata [Matthew, 1886, p. 41].

*Piscinopsis gulielmi [Matthew, 1886, p. 39].

Protorthis billingsi [U. 8. National Museum and Mat-
thew, 1886, p. 44].

*Protorthis latourensis (U. 8. National Museum).

Protorthis quacoensis [Matthew, 1886, p. 44].

Stenotheca acadica (U.S. National Museum).

Eocystites primevus (U. 8. National Museum).

Agnostus vir [U. S. National Museum and Matthew, 1886,
p. 70).

Microdiscus dawsoni (U. 8. National Museum).

Paradoxides eteminicus (U. S. National Museum).

Paradoxides eteminicus suricoides (U. S. National Mu-
seum).

Paradoxides lamellatus (U. S. National Museum).

301h (references follow species). (For stratigraphic pos
of Division 1c of Matthew, on Hanford Brook, §
Lingulella dawsoni [Matthew, 1886, p. 34]=Lingulella
ferruginea.
Acrothele matthewi [Matthew, 1886, p. 41].
*Archeeocyathus? pavonoides [Matthew, 1886, p. 30].

| Paradoxides micmac [U.S. National Museum and Matthew,
1886, p. 81].

Ptychoparia orestes ties (U. 8. National Museum).

Ptychoparia (Liostracus) ouangondiana (U.S. National
Museum).

Ptychoparia (Liostracus) tener (U. S. National Museum).

Ctenocephalus matthewi (U. S. National Museum.)

Ctenocephalus matthewihispidus(U.S. National Museum). -

Ctenocephalus matthewi perhispidus (U. 8. National Mu-
seum).

Ctenocephalus (Harttella) matthewi (U.S. Narblowel! Mu-
seum).

Conocoryphe (Bailiella) baileyi (U.S. National Museum).

Conocoryphe (Bailiella) baileyi arcuata (U. 8. National
Museum).

Conocoryphe (Bailiella) elegans (U. 8. National Museum),

Conocoryphe (Bailiella) walcotti (U.S. National Museum).

ition and association, see p.132.) Middle Cambrian: Shales
t. John County, New Brunswick.

*Stenotheca nasuta [Matthew, 1886, p. 58].

Agnostus vir [Matthew, 1886, p. 70].

Paradoxides micmac [Matthew, 1886, p. 81].

Eocoryne geminum [Matthew, 1886, p. 31].

*Diplotheca acadica obtusa [Matthew, 1886, p. 55].

801i. (For stratigraphic position and association, see p.

133.) Middle Cambrian: Layers of Division 1b1 of Matthew,

on Hanford Brook, St. John County, New Brunswick.

Acrothele matthewi.

301j (references follow species).

Acrothele matthewi [Walcott, 1884a, p. 16]

*Protorthis billingsi [Walcott, 1884a, p. ieyfbese two sp

(For stratigraphic position and association, see p. 132.) Middle Cambrian: Shales
of the St. John formation at Ratcliffs Millstream,

St. John County, New Brunswick.

ecies may not occur in the same bed.

LOCALITIES.

801k (references follow species; see 308i).

231

(For stratigraphic position and association, see p. 182.) Middle Cam-

brian: St. John formation in the city of St. John, St. John County, New Brunswick.

Lingula dawsoni
ferruginea.

*Acrothele matthewi [ Walcott, 1884a, p. 16].

Acrotreta sagittalis transversa (U.S. National Museum).

_Protorthis billingsi (U. 8. National Museum).

EKocystites primzevus (U.S. National Museum).

Hyolithes danianus (U. 8. National Museum).

Stenotheca acadica (U. 8. National Museum).

Harttia matthewi (U.S. National Museum).

Agnostus acadicus (U. 8. National Museum).

Microdiscus pulchellus (U. S. National Museum).

Microdiscus punctatus (U. 8. National Museum).

[Walcott, 1884a, p. 15]=Lingulella

3011 (references follow species).

Paradoxides acadicus (U. 8. National Museum).
Paradoxides eteminicus (U. S. National Museum).
Ctenocephalus matthewi oe . National Museum).
Conocoryphe matthewi (U.S. National Museum).
Conocoryphe (Bailiella) baileyi (U. 8. National Museum).
Conocoryphe (Bailiella) elegans ‘U. S. National Museum).
Ptychoparia orestes (U. S. National Museum).
Ptychoparia robbi (U. S. National Museum).
Ptychoparia (Liostracus) ouangondiana aurora (U. S.
National Museum).
Ptychoparia (Liostracus) tener (U. S. National Museum).

(For stratigraphic position and association, see p. 132.) Middle Cambrian: Shales

of Division 1d of Matthew, on Porters Brook, St. Martins, St. John County, New Brunswick.

Lingulella dawsoni [Matthew, 1886, p. 34]—Lingulella |
| *Stenotheca hicksiana [Matthew, 1886, p. 57].

ferruginea.

*Lingulella linguloides [Matthew, 1886, p. 34]=Lingu-
lella ferruginea.

Acrothele matthewi [Matthew, 1886, p. 41].

Acrothele prima costata [Matthew, 1895a, p. 128].

Acrotreta misera [Matthew, 1886, p. 36].

*Protospongia (?) minor distans [Matthew, 1886, p. 30].

Eocoryne geminum [Matthew, 1886, p. 31].

*Dendroverapsus (?) primordialis [Matthew, 1886, p. 31].

*Protograpsus alatus [Matthew, 1886, p. 32].

Hyolithes (Camerotheca) danianus [Matthew, 1886, p. 50].

*Hyolithes (Camerotheca) gracilis [Matthew, 1886, p. 51]. |

Diplotheca acadica [U. S. National Museum and Mat- |
thew, 1886, p. 55].

*Diplotheca acadica sericea [U. S. National Museum and
Matthew, 1886, p. 55].

*Diplotheca hyattiana caudata [U. 8. National Museum
and Matthew, 1886, p. 54].

301m (references follow species).

*Stenotheca concentrica [Matthew, 1886, p. 57].

*Lepiditta curta [Matthew, 1886, p. 62].

*Aonostus acadicus declivis [U. 8. National Museum and
Matthew, 1886, p. 71].

*Aonostus acutilobus [U. S. National Museum and Mat-
thew, 1886, p. 74].

*Aonostus obtusilobus [Matthew, 1886, p. 73].

*Aonostus tessela [U. 8. National Museum and Matthew,
1886, p. 71].

*Aonostus umbo [Matthew, 1886, p. 72].

*Aonostus vir concinnus [U. 8. National’ Museum and
Matthew, 1886, p. 70].

Microdiscus punctatus pulchellus [U. S. National Museum
and Matthew, 1886, p. 75].

*Paradoxides abenacus [Matthew, 1886, p. 80].

*Solenopleura acadica [Matthew, 1886, p. 77].

(For stratigraphic position and association, see p. 132.) Middle Cambrian: Shale

of Division 1c of Matthew’s section on Porters Brook, St. Martins, St. John County, New Brunswick.

Protorthis quacoensis [Matthew, 1886, p. 44].
*Stenotheca radiata [Matthew, 1886, p. 58].

301n [Matthew, 1892, p. 39].

Hyolithes (Camerotheca) danianus [Matthew, 1886, p. 50].
Eocoryne geminum (U. 8. National Museum).

(For stratigraphic position and association, see p.131.) Upper Cambrian: Shales of

Division 3a of Matthew, on the “‘right shore,” below the “‘ialls,”” St. John Harbor, St. John County, New

Brunswick.
*Lingulella levis.

301s [Matthew, 1894, p. 91].

Lower Ordovician: Gray sandstones of Division 3e (?) of Matthew, at McAphee’s

Corner, Hardingville, St. John County, New Brunswick.

*Lineulella grandis.
f=) to)

301t [Matthew, 1903, p. 201].

(For stratigraphic position and association, see p. 131.) Upper Cambrian: Sandy

shales of Division 03a of Matthew, at Carlton shore, near the puspensio2 bridge, St. John, St. John County,

New Brunswick.
Lingulella levis grandis.

301u (references follow species).

(For stratigraphic position and association, see p.131.) Upper Cambrian: Shales

of Division C3b of Matthew, in the St. John Basin, St. John County, New Brunswick.

Lingulella cf. lepis [Matthew, 1903, p. 204].
Sphzerophthalmus alatus [Matthew, 1903, p. 240].

232

301v [Matthew, 1890, p. 155]. Lower Cambrian: Sandy shales of Division 2b of the “basal series’’ of Matthew,
on Hanford Brook, St. John County, New Brunswick.
*Rustella major.
The following species were found at the same locality and approximate horizon [Walcott, 1900, p. 322]:
Micromitra (Paterina) labradorica.
Hyolithes cf. communis.
Coleoloides cf. typicalis.

CAMBRIAN BRACHIOPODA.

301w (references follow species; see 301g, 308h, and 308i). (For stratigraphic position and association, see p. 132.)
Middle Cambrian: Shales of Division 1¢2 of Matthew’s section at Portland (now part of the city of St. John),
St. John County, New Brunswick.
Discinopsis gulielmi (U. S. National Museum).
Acrothele matthewi (U. 8S. National Museum).
*Pyotorthis latourensis [U. S. National Museum and

Paradoxides acadicus suricus [Matthew, 1886, p. 78].
Paradoxides eteminicus (U. 8. National Museum).
Ctenocephalus matthewi (U. S. National Museum).

Matthew, 1886, pp. 42 and 82]. Ctenocephalus matthewi hispidus (U. 8S. National
Protorthis quacoensis (U. S. National Museum). Museum).
Hyolithes (Camerotheca) micmac [Matthew, 1886, p. 81]. | Ptychoparia (Liostracus) ouangondiana (U. 8. National
Stenotheca triangularis [Matthew, 1886, pp. 58 and 83]. Museum).

Stenotheca (Parmophorella)
p- 60].

Agnostus regulus [Matthew, 1886, pp. 68 and 84].

Microdiscus dawsoni [Matthew, 1886, pp. 75 and 84].

acadica [Matthew, 1886, | Conocoryphe (Bailiella) baileyi (U.S. National Museum).
Conocoryphe (Bailiella) baileyi arcuata (U. S. National
Museum).

Conocoryphe (Bailiella) walcotti (U.S. National Museum).

301x [Matthew, 1891, p. 148, and on label with the specimens in Matthew’s collection]. (For stratigraphic posi-
tion and association, see p. 131.) Middle Cambrian: Sandstones of Division ©2c of Matthew, Dunns Shore,
Simonds, near St. John, St. John County, New Brunswick.
Lingulella radula aspera—Lingulella radula.

301y [Matthew, 1891, p. 148, and Museum of Comparative Zoology]. For stratigraphic position and association,
see p. 131.) Middle Cambrian: Shaly sandstones of Division C2c of Matthew, east side of Courtney Bay,
St. John, New Brunswick.
*Lingulella radula aspera—Lingulella radula.

301z (references follow species). (For stratigraphic position and association, see p. 182.) Middle Cambrian: Divi-
sion le of Matthew, on Ratclifis Millstream, St. John County, New Brunswick.
Lingulella dawsoni [Matthew, 1886, p. 34]=Lingulella | Hyolithes (Camerotheca) danianus [Matthew, 1886, p. 50].
ferrucinea. Conocoryphe (Bailiella) elegans(U.S. National Museum).
Harttia matthewi [Matthew, 1886, p. 61].

302 [U. S. National Museum]. Middle Cambrian: Limestone east of West Gallatin (Gallatin) River, above
Gallatin, Gallatin County, Mont. .

Micromitra pealei.

*Micromitra sculptilis.

Obolus matinalis.

*Acrotreta attenuata.

*Acrotreta attenuata var.
Eoorthis hamburgensis.
Eoorthis sp.

302a [U. S. National Museum]. Middle Cambrian: Limestones at several places on the south side of Gallatin
Valley, Gallatin County, Mont.
Micromitra sculptilis.
Acrotreta idahoensis. F

302b [U.S. National Museum]. Middle Cambrian: Limestones near Crowfoot Ridge, Gallatin quadrangle (U.S.
G. S.), Yellowstone National Park, Wyo.

Micromitra sculptilis.
*Micromitra sp. undt.
Obolus rotundatus.
Lingulella desiderata.
Lingulella sp.

*Lingulella (Lingulepis) acuminata meeki.
Dicellomus nanus.

Acrotreta idahoensis.

Eoorthis remnicha.

These species may not all be from the same bed or irom exactly the same locality.

302c [U. S. National Museum]. Upper Cambrian: Shaly limestone on south side of Gallatin Valley, Yellowstone

National Park, Wyo.
Micromitra sculptilis.
*Koorthis iddingsi.

LOCALITIES. 233

802d [U.S. National Museum]. Upper Cambrian: Limestone 200 yards (183 m.) north of the southwest corner of
sec. 18, T. 28 N., R. 113 W., Uinta County, Wyo. (E. E. Smith).
Obolus matinalis.
Obolus sinoe.
Koorthis iddingsi.

302e [U. S. National Museum]. Upper Cambrian: Limestone near the top of the Deadwood formation in Big
Popo Agie Canyon, near Lander, Fremont County, Wyo. (N. H. Darton).
EKoorthis wichitaensis.

302f [U. S. National Museum]. Upper Cambrian: Upper part of the Gallatin formation, north side of Elk Pass,
between Buffalo and Slough creeks, Yellowstone National Park, Livingston quadrangle (U. S. G. §.),
Mont.
Billingsella coloradoensis.
Otusia sandbergi.

302g [U. S. National Museum]. Upper Cambrian: Limestone on the north slope of Crowfoot Ridge, south of the
Gallatin Valley, Gallatin quadrangle (U.S. G.8.), Yellowstone National Park, Wyo.
Billingsella coloradoensis.

302h [U. S. National Museum]. Upper Cambrian: Limestone on the divide between Panther Creek and
Gallatin River, Gallatin quadrangle (U.S. G. 8.), Yellowstone National Park, Wyo.
Billingsella coloradoensis.

- 302j [U.S. National Museum records]. Lower Ordovician: Limestone on the east side of West Gallatin (Gallatin)
River, above Gallatin, Gallatin County, Mont.
Obolus matinalis.

*Clarkella Geant junese species may not be from the same exact locality.

302k [U. S. National Museum]. Middle Cambrian: Limestone near Gallatin, Threeforks quadrangle (U. S.
. G.8.), Gallatin County, Mont.
Dicellomus politus.

8021 [U.S. National Museum]. Middle Cambrian: Limestone in the Gallatin Range, Yellowstone National Park,
Wyo.
*Lingulella desiderata.

302m [U.S. National Museum]. Middle Cambrian: Middle of shale above lower sandstone on Billy Creek, in the
Bighorn Mountains, Sheridan County, Wyo. (N. H. Darton, 1902).
Lingulella (Lingulepis) acuminata.
Dicellomus nanus.

302n [U. S. National Museum]. Upper Cambrian: Limestone on the south side of the Gallatin Valley, Gallatin
County, Mont.
Eoorthis remnicha.

3020 [U. S. National Museum]. Middle Cambrian: Sandstones just above the granite west of Garfield Peak, 50
miles (80.5 km.) west of Casper, Natrona County, Wyo. (N. H. Darton).
*Obolus (Westonia) dartoni.

302p [U. S. National Museum]. Upper Cambrian: Middle limestone of the Deadwood formation near the summit
of the Owl Creek Mountains, 18 miles (29 km.) southwest of Thermopolis, Fremont County, Wyo. (N. H.
Darton).
Billingsella coloradoensis.
Huenella abnormis.
Ptychoparia.

302q [U. S. National Museum]. Upper Cambrian: About 1,000 feet (305 m.) above the quartzitic sandstones in
the ‘‘ Yogo limestone (Devono-Silurian)”’ of W. H. Emmons [1907, p. 34], on Rock Creek, Phillipsburg quad-
rangle (U.S. G.S.), Granite County, Mont. (E. M. Kindle, 1907).
Billingsella coloradoensis.

302r [U. S. National Museum]. Upper Cambrian: About 1,000 feet (305 m.) above the quartzitic sandstones in
the ‘‘ Yogo limestone (Devono-Silurian)” of W. H. Emmons [1907, p. 34], near Princeton, Phillipsburg quad-
rangle (U.S. G. S.), Granite County, Mont. (E. M. Kindle, 1907).
Obolus cf. discoideus. Agraulos.
Billingsella coloradoensis. Anomocare.
Cyrtolites.

234 CAMBRIAN BRACHIOPODA.

802s [U. S. National Museum]. Middle Cambrian: Dark siliceous shale in a quarry in Last Chance Gulch, south
slope of Mount Helena, 1.5 miles (2.4 km.) south of Helena, Jefferson County, Mont.
, Obolus (Westonia) ella.
*Lingulella helena.
Dicellomus politus.

302t [U. S. National Museum]. Middle Cambrian: Limestone northeast of Logan, Threeforks quadrangle (U. 8.
G.S8.), Gallatin County, Mont.
Micromitra (Iphidella) pannula.
Acrotreta sp. undt.
Ptychoparia.

302u [U.S. National Museum]. Upper Cambrian: Upper limestone of the Deadwood formation north of Cheever’s
ranch, on the summit of the Bighorn Mountains, Wyo. (N. H. Darton).
Dicellomus nanus.

302v [U. S. National Museum]. Ordovician: Sandstones 2 miles (3.2 km.) west of the main summit of Buffalo
Fork Peak [see St. John, 1877, pp. 468 and 469 and map opposite p. 324 (near station XLIX)], about 25 -
miles (40 km.) east of Jackson Lake, Uinta County, Wyo.
Dicellomus nanus.

302w [U. S. National Museum]. Middle Cambrian: Limestone at Madison. Mountain, Mont.
Acrotreta idahoensis.
Billingsella coloradoensis.

302x[U.S. National Museum]. Middle Cambrian: Sandstones near the head of Powder River, Bighorn Mountains,
Wyo. (Ff. V. Hayden).
Obolus sinoe.

302y [U. S. National Museum]. Middle Cambrian: Sandstone on Johnson Creek, Bighorn Mountains, Wyo.
(N. H. Darton, 1902).
Dicellomus nanus.

302z [U. S. National Museum]. Middle Cambrian: Limestone on Mill Creek, near Landusky, Little Rocky
Mountains, Chouteau County, Mont. (W. H. Weed). ;
Dicellomus nanus.

303 [Barrande, 1879b, Pl. XCV]. (For stratigraphic position and association, see p. 124.) Lower Ordovician: Etage
d3 at K6énigshof, Bohemia, Austria-Hungary.
*Acrotreta babel.

303a (references follow species). (For stratigraphic position and association, see p. 124.) Lower Ordovician:
Etage d3 at Trubin, Bohemia, Austria-Hungary.
Lingulella? simplex [Barrande, 1879b, Pl. CIV].
Acrotreta babel? [Barrande, 1879b, Pl. XCV].

303b [Barrande, 1879b, Pl. CX XVI]. (For stratigraphic position and association, see p. 124.) Lower Ordovician:
Etage d1 in the environs of Rokitzan, Bohemia, Austria-Hungary.
*Obolus? rokitzanensis.

308c (references follow species). (For stratigraphic position and association, see p. 124.) Passage beds between
the Upper Cambrian and the Ordovician: Suburbs of Hof, Bavaria, Germany.

*Obolus? bavaricus [Barrande, 1868a, p. 100]. *Lingulella wirthi [Barrande, 1868a, p. 101).
*Obolus? minor [Barrande, 1868a, p. 105]. *Acrotreta inchoans [Barrande, 1868a, p. 102].
*Obolus? palliatus [Barrande, 1868a, p. 105]. *Orbiculoidea contraria [Barrande, 1868a, p. 104].
*Lingulella cedens [Barrande, 1868a, p. 102]. *Orbiculoidea varians [Barrande, 1868a, p. 103].
*Lingulella? humillima [Barrande, 1868a, p. 101]. *Koorthis bavarica [Barrande, 1868a, p. 99].

*Lineulella signata [Barrande, 1868a, p. 103].

303d (references follow species). (For stratigraphic position and association, see p. 124.) Lower Ordovician:
’ Etage dl at Swarow, Bohemia, Austria-Hungary.
*Obolus? advenus [Barrande, 1879b, Pl. XCY].
Lingulella? insons [Barrande, 1879b, Pl. CV].
*Acrotreta? minima [Barrande, 1879b, Pl. XCV].

LOCALITIES. 230

803e [Barrande, 1879b, Pl. CV]. (For stratigraphic position and association, see p. 124.) Lower Ordovician:
Htage dl at Sta. Benigna, Bohemia, Austria-Hungary.
*Lineulella? insons. \

303i [Pompeckj, 1896a, pp.7and 8]. (For stratigraphic position and association, see p.124.) Passage beds between
the Upper Cambrian and the Ordovician: Railway cut near Schellenberg, a little distance back of the
railway station at Neuhof, near Hof, Bavaria, Germany.

Lingulella cedens. Orthis sp.—Eoorthis bavarica.
Lingulella? humillima. Macrocystella bavarica.
Lingulella wirthi. Bellerophon n. sp.

Lingula n. sp. Bavarilla hofensis.

Acrotreta inchoans. Dikellocephalus (?) bavaricus.
Acrotreta n. sp. Niobe innotata.

Orbiculoidea contraria. Niobe discrepans.
Orbiculoidea varians.

303g [Barrande, 1879b, Pl. CXI]. (For stratigraphic position and association, see p. 124.) Lower Ordovician:
Htage dl at Rabenberg, Bohemia, Austria-Hungary.
*Obolus? ancillus.
Obolus? complexus.

303h [Barrande, 1879b, Pl. XCV]. (For stratigraphic position and association, see p. 124.) Lower Ordovician:
Htage di at Milinsky Wrch, near Woleschna, Bohemia, Austria-Hungary.
Obolus complexus.

303i (references follow species). (Hor stratigraphic position and association, see p. 124.) Lower Ordovician:
Iitage dl at Kruschna Hora, Bohemia, Austria-Hungary. ;
*Obolus complexus [Barrande, 1879b, Pl. XCY].
*Obolus feistmanteli [Barrande, 1879b, Pl. CX].

303j [Barrande, 1879b, Pl. CVI]. (For stratigraphic position and association, see p. 124.) Lower Ordovician: Htage
dl at Czerhowitz, Bohemia, Austria-Hungary.
Obolus feistmanteli.

303k [Barrande, 1879b, Pl. CXI}. (For stratigraphic position and association, see p. 124.) Lower Ordovician:
BHtage dl at Hradischt, Bohemia, Austria-Hungary.
*Obolus? mirandus.

3031 [Barrande, 1879b, Pl. CVI]. (For stratigraphic position and association, see p. 124.) Lower Ordovician:
Etage dl at Libetschov, Bohemia, Austria-Hungary.
*Obolus? (Westonia?) lamellosus.
Lingula? eximia.

303m [Barrande, 1879b, Pl. CIV]. (For stratigraphic position and association, see p. 124.) Ordovician Etage
d4 at Lieben, Bohemia, Austria-Hungary. f
*Lingulella dayidson1.

3038n [Barrande, 1879b, Pl. CIV]. (For stratigraphic position and association, see p. 124.) Ordovician: Etage d4
at Wraz, Bohemia, Austria-Hungary.
Lingulella davidsoni.

8080 [Barrande, 1879b, Pl. CIV]. (For stratigraphic position and association, see p. 124.) Ordovician: Etage d4
at Lodenitz, Bohemia, Austria-Hungary.
Lingulella dayidsoni.

303p [Barrande, 1879b, Pl. CIV]. (For stratigraphic position and association, see p. 124.) Lower Ordovician:
Etage d3 in the environs of Beraun, Bohemia, Austria-Hungary.
*Lingulella? simplex.

304 [Matley, 1902, p. 145]. (For stratigraphic position and association, see p. 135.) Upper Cambrian: “Bronsil”
shales at White Leaved Oak, Malvern Hills, between Herefordshire and Worcestershire, England.
Acrotreta belti.

236 CAMBRIAN BRACHIOPODA.

304a [Groom, 1902, p. 110]. (For stratigraphic position and association, see p. 135.) Upper Cambrian: “‘Bronsil”
shales, Malvern Hills, between Herefordshire and Worcestershire, England.

Obolus (Bréggeria) salteri. (?) Hyolithes assulatus Groom.
Lingulella nicholsoni. Agnostus dux Callaway.

Lingulella? sp.=Acrothyra?. Cheirurus frederici Salter.

Lingula sp. Platypeltis croftii Callaway ?.
Acrotreta belti. Asaphellus affinis McCoy?.

Acrotreta cf. nicholsoni. Parabolinella (?) triarthrus Callaway?.
Acrotreta sabrine. Acanthopleurella grindrodi Groom.
Acrotreta cf. socialis. Niobe homfrayi Salter?.

Dictyonema sociale Salter. (?) Niobe? sp., near O. peltata Salter.
Tomaculum problematicum Groom.

304b [Groom, 1902, p. 109]. (For stratigraphic position and association, see p.135.) (See 304f, the “black shales”
being another name for the ‘‘White Leaved Oak shales”). Upper Cambrian: Lower part of the ‘‘ White
Leaved Oak” shales (the zone of Polyphyma), Malvern Hills, between Herefordshire and Worcestershire,

England.
Micromitra pusilla. Small ostracod.
Lingulella nicholsoni (doubtfully). Protospongia fenestrata Salter.
Acrotreta sabrinz. Plant remains (?).
Polyphyma lapworthi Groom. Agnostus sp.

304c [Groom, 1902, p. 94]. (For stratigraphic position and association, see p. 136.) Lower Cambrian: “‘Malvern
quartzite” at Raggedstone Hill, Malvern Hills, between Herefordshire and Worcestershire, England.
Micromitra (Paterina) phillipsi. Hyolithes fistula (Holl).
Obolella groom. Hyolithes primzvus Groom.

304d [Groom, 1902, p. 94]. (For stratigraphic position and association, see p. 136.) Lower Cambrian: ‘‘Malvern
quartzite ’’ at Midsummer Hill, Malvern Hills, between Herefordshire and Worcestershire, England.
Micromitra (Paterina) phillipsi.
Obolella groomi.

304e [Davidson, 1866, p. 62]. (For stratigraphic position and association, see p. 135.) Upper Cambrian: Upper
part of the black ‘‘White Leaved Oak” shales at Coal Hill, east end of the Malvern Hills, between Hereford -
shire and Worcestershire, England.
*Obolus (Bréggeria) salteri.

304f [Salter, 1865, p.102]. (For stratigraphic position and association, see p. 135.) (See 304b, the “‘black shales”

being another name for the ‘‘ White Leaved Oak shales.”) Upper Cambrian: *‘Black shales” in the Malvern

Hills, between Herefordshire and Worcestershire, England.
*Lineulella (Lingulepis?) pygmea.

,

304g (references follow species). (For stratigraphic position and association, see p. 135.) Upper Cambrian: Sand-
stones of the Hollybush series (horizon of Middle Lingula beds [Davidson, 1866, p. 63]), Malvern Hills,
between Herefordshire and Worcestershire, England.
*Micromitra (Paterina) phillipsi [Holl, 1865, p. 89].
*Lingulella (Lingulepis?) squamosa [Holl, 1865, p. 102].
Groom [1902, p. 109] cites the followiag from the “‘Hollybush sandstones”:

Micromitra phillipsi. Hyolithes, 2 or more species.
Acrotreta sagittalis?. Coleoloides? sp.

Hyolithes fistula (Holl). Scolecoderma antiquissima (Salter).
Hyolithes malvernensis Groom. Modiolopsis? sp.

Hyolithes primzevus Groom. Foraminifera (glauconitic casts).

304h [U.S. National Museum]. (For stratigraphic position and association, see p. 185.) Upper Cambrian: Shineton
shales, Mary Dingle, South Shropshire, England.
Acrotreta nicholsoni.
*A crotreta sabrine.

304i [Callaway, 1877, p. 669]. (For stratigraphic position and association, see p. 135.) Upper Cambrian: Shineton
shale at Shineton, Mary Dingle, Dryton, Cressage, 1 mile (1.6 km.) west of Cressage, west of Harley, and.
under Cound-Moor quarry, all in South Shropshire, England.
*Lingulella nicholsoni.
Acrotreta sabrine.

304j [Mason College collections]. (For stratigraphic position and association, see p.135.) Upper Cambrian: Lower
Stockingford shales, Puxley Park Lane, haifway up the path to the quarry, Atherstone, Warwickshire,
England (C. A. Matley, 1894).
Acrothele intermedia?.
Acrotreta sabrine.

LOCALITIES. 237

304k [Davidson, 1883, pp. 208 and 209]. (For stratigraphic position and association, see p. 135.) Upper Cambrian:
Shineton shale at Bull Hill Cottage and Pewardine, both in South Shropshire, Eneland.
Lingulella nicholsoni.

3041 [Geol. Survey Great Britain]. (See 304p.) (For stratigraphic position and association, see p. 185.) Upper
Cambrian: Shineton shales at the following localities of the Geological Survey of Great Britain: 2246, 2481,
2499, 2512, 2513, 2541, 2548, 2556, 2567, 2625, and 2627, all of which are on Shineton Brook and vicinity,
r South Shropshire, England.
Lingulella nicholsoni.

304n [McCoy, 1854, p. 254]. (For stratigraphic position and association, see p. 135.) Ordovician: ‘‘Coniston (Bala)
limestone ”’ at Coniston, Lancashire, England.
Lingulella davisi.

3040 [U.S. National Museum]. (For stratigraphic position and association, see p. 186.) Lower Cambrian: Sand-
stone at Nuneaton, England.
Micromitra (Paterina) labradorica.

8304p [Geol. Survey Great Britain]. (See 3041.) (For stratigraphic position and association, see p. 135.) Upper
Cambrian: Shineton shales at the following localities of the Geological Survey of Great Britain: 2495, 2536,
2548, 2545, 2558, and 2580, all of which are on Shineton Brook, South Shropshire, England (Chas. Lapworth).

Acrotreta sabrinz.

305 [Davidson, 1871, p. 341]. (For stratigraphic position and association, see p. 135.) Upper Cambrian: Lower
Tremadoe shales, Craig-y-dinas, North Wales.
*A crotreta belti.

305a [Davidson, 1866, desc. of Pl. III]. (For stratigraphic position and association, see p. 135.) Upper Cambrian:
Upper Tremadoc beds at Moel-y-gest, northwest side, Carnarvonshire, North Wales.
Lingulella lepis.

305c. (For stratigraphic position and association, see p. 135.) Upper Cambrian: Lower Tremadoc slate, every-
where in the Tremadoc district, Carnarvonshire, North Wales.
Lingulella lepis.

305d [Davidson, 1866, p. 54]. (For stratigraphic position and association, see p. 135.) Upper Cambrian: In the
Upper Lingula flags near Tremadoc, Carnarvonshire, North Wales.
Lingulella lepis?. ;

305e [Davidson, 1866, p. 54]. (For stratigraphic position and association, see p. 135.) Upper Cambrian: Upper
Tremadoc beds near Tai-hirion, Arenig, North Wales.
Lingulella lepis.

305f [Davidson, 1866, p. 54]. (For stratigraphic position and association, see p. 135.) Upper Cambrian: Lower
Tremadoc beds east of Pont Nant-y-Ladron, on the Bala road from Ffestiniog, Merionethshire, North Wales.
Lingulella lepis.

305g [Davidson, 1866, p. 54]. (For stratigraphic position and association, see p. 135.) Upper Cambrian: Lower
Tremadoc at Wern, North Wales.
Lingulella lepis.

305h [Davidson, 1866, p. 54]. (For stratigraphic position and association, see p. 135.) Upper Cambrian: Lower
Tremadoc at Borthwood, North Wales.
*Lingulella lepis.

305i [Davidson, 1866, p. 54]. (For stratigraphic position and association, see p. 135.) Upper Cambrian: Lower
Tremadoe at Trwyn-y-lago, North Wales.
Lingulella lepis.

305j [Davidson, 1866, p. 54]. (For stratigraphic position and association, see p. 135.) Upper Cambrian: Lower
Tremadoc at Cefn Cyiarnedd, North Wales.
Lingulella lepis.

306 [Geol. Survey Canada]. Upper? Cambrian: Sandy limestone on Gravel River, eastern slope of the Rocky
Mountains, in the Mackenzie basin, British Columbia (J. Keele, 1908).
Billingsella coloradoensis.
Eoorthis desmopleura?.

238

307 (references follow species).

CAMBRIAN BRACHIOPODA.

(For stratigraphic position and association, see p. 131.) Upper Cambrian: Shales

of Division C3c of Matthew on McLeod Brook (=Barachois River), Cape Breton, Nova Scotia.

Obolus refulgens [Matthew, 1903, p. 213].

*Lingulella concinna [Matthew, 1903, p. 204].

Leptobolus gemmulus [Matthew, 1903, p. 192]—Lingulella
ferruginea.

807a (references follow species).

Leptobolus cf. linguloides [Matthew, 1903, p. 193]=Lingu-
lella ferruginea.

Linnarssonia cf. belti [Matthew, 1903, p. 210].

*Acrotreta bisecta [Matthew, 1903, p. 187].

*Schizambon priscus [Matthew, 1903, p. 188].

.

(For stratigraphic position and association, see p. 131.) Upper Cambrian: Shales

of Division C3c2 of Matthew [1903, p. 240], on McLeod Brook (=Barachois River), near Boisdale, eastern

Cape Breton, Nova Scotia:
*Lingulella cf. davisi [Matthew, 1903, p. 203].
*Lingulella cf. lepis [Matthew, 1903, p. 240].
Lingulella cf. linguloides [Matthew, 1903, p. 240]=Lingu-
lella ferruginea.
Acrotreta sipo [Matthew, 1903, p. 186]=Acrotreta bisecta.
*Urotheca sp. [Matthew, 1903, p. 183].
*Modiolopsis? cf. solvensis [Matthew, 1903, p. 217].
*Bellerophon bretonensis [Matthew, 1903, p. 218].

307b [U.S. National Museum].

*Bellerophon insule [Matthew, 1903, p. 217].
*Bellerophon semisculptus [Matthew, 1903, p. 219].
*Parabolinella? cf. limitis [Matthew, 1903, p. 226].
*Parabolinella? quadrata [Matthew, 1903, p. 226].
*Triarthrus belli [Matthew, 1903, p. 231].
*Angelina? sp. [Matthew, 1903, p. 232].
*Asaphellus homfrayi var. [Matthew, 1903, p. 235].
*Asaphellus? planus [Matthew, 1903, p. 238].

(For stratigraphic position and association, see p. 131.) Middle Cambrian: Sand-

stone on McPhees Brook, Cape Breton, Nova Scotia.

Lingulella radula.

307c [Matthew, 1903, p. 205].

(For stratigraphic position and association, see p. 131.) Middle Cambrian: Sand-

stones probably belonging with Division O2c of Matthew, on Mira River, eastern Cape Breton, Nova

Scotia.
Lingulella radula.

307d (references follow species).

(For stratigraphic position and association, see p. 134.) Middle Cambrian:

Sandy limestone of Division E2a? of Matthew’s Etcheminian on Young (McFees) Point *[Matthew,
1903, p. 19], near George River station, Cape Breton, Nova Scotia.

*Obolus zequiputeis [Matthew, 1903, p. 140]=Obolus sel-
wynl.

*Obolus selwyni [Matthew, 1903, p. 123].

*Lineulella atava insule [Matthew, 1903, p. 110].

Obolus discus [Matthew, 1903, p. 79]=Lingulella triparilis.

*Lineulella (Lingulepis) roberti [Matthew, 1903, p. 132].

Acrotreta sp. [Matthew, 1903, p. 96].

*Billingsella retroflexa [Matthew, 1903, p. 149].
*Hyolithes cf. tenuistriatus [Matthew, 1903, p. 83).
*Paradoxidoid trilobite [Matthew, 1903, p. 176].
*Holasaphus centropyge [Matthew, 1903, p. 176].
*Eurypterid (?) crustacean [Matthew, 1903, p. 79].

307e [Matthew, 1903, p. 216]. (For stratigraphic position and association, see p. 131.) Upper Cambrian: Lime-
stone in Division C3b? (possibly C3c) on Gillis Brook, eastern Cape Breton, Nova Scotia.

Orusia lenticularis.

307f [Matthew, 1903, p. 198].

(For stratigraphic position and association, see p. 1382.) Middle Cambrian: Shales

of Division ©2a on McLean Brook, Mira River, Cape Breton, Nova Scotia.

Lingulella (Lingulepis) exigua.

307g (references follow species). (For stratigraphic position and association, see p. 132.) Middle Cambrian: Shales

of Division C2b on McLean Brook, above Marion Bridge, Mira River, Cape Breton, Nova Scotia. \
Lineulepis starri var. [Matthew, 1903, p. 195]=Lingulella (Lingulepis) exigua.
Lingulepis starri exigua [Matthew, 1903, p. 198]=Lingulella (Lingulepis) exigua.

Beyrichia triceps [Matthew, 1903, p. 220].

307h [Matthew, 1903, p. 216]. (For straticraphic position and association, see p. 131.) Upper Cambrian: In Divi-
sion C3b? (possibly C3c) on McLeod Brook (=Barachois River), eastern Cape Breton, Nova Scotia.

Orusia lenticularis.

807i (references follow species).

(For stratigraphic position and association, see p. 131.) Upper Cambrian: In

Division ©3b of Matthew’s section on McNeil Brook, east of Mira River, eastern Cape Breton, Nova Scotia.

Orusia lenticularis [Matthew, 1903, p. 216].
*Aonostus acadicus cf. declivis [Matthew, 1903, p. 223].
Agnostus trisectus? [Matthew, 1903, p. 223].

Sphzerophthalmus alatus [Matthew, 1903, p. 229].
Peltura scarabzeoides [Matthew, 1903, p. 223].
Ctenopyge lobata? [Matthew, 1903, p. 223].

LOCALITIES.

307j (references follow species).

(For stratigraphic position and association, see p. 131.)

239

Upper Cambrian: Lime-

stone in Division C3b? (possibly C3c), on East Bay, east of Bras d’Or Lake, eastern Cape Breton, Nova Scotia.

Orusia lenticularis [Matthew, 1903, p. 216].
*Aonostus trisectus germanus [Matthew, 1903, p. 221].
*Aenostus cf. cyclopyge [Matthew, 1903, p. 222

308 (references follow species).
of Division C3c of Matthew, at Navy Island, St.
*Obolus refulgens [Matthew, 1892, p. 45].
*Obolella gemmula [Matthew, 1892, p. 41]=Lingulella
ferruginea.

308a [Matthew, 1893b, p. 103].

(For stratigraphic position and association, see p. 131.)

*Parabolina dawsoni [Matthew, 1903, p. 224].
Ctenopyge pecten [Matthew, 1903, p. 230].

Upper Cambrian: Shales
John Harbor, New Brunswick.

Schizambon priscus [Matthew, 1901a, p. 278].

Acrotreta baileyi|Matthew, 1892, p.43]=Acrotreta bisecta.
*Jimnarssonia belti? [Matthew, 1892, p. 42].

(For stratigraphic position and association, see p. 131.) Upper Cambrian: Dark

shales of Division C3a of Matthew’s section of the St. John terrane, Navy Island, St. John Harbor, St. John

County, New Brunswick.
*Koorthis atava.

808b (references follow species).

(For stratigraphic position and association, see p. 131.) Upper Cambrian: Lime-

stone lentiles in black shales of Division C3a of Matthew’s section, Germaine Street, St. John, St.John

County, New Brunswick.
Orusia lenticularis [Matthew, 1892, p. 48].
*Orusia lenticularis atrypoides [Matthew, 1892, p. 48].
*Orusia lenticularis lyncioides [Matthew, 1892, p. 48].
*Eoorthis johannensis [Matthew, 1892, p. 49].

308¢ [Matthew, 1891, p. 147].

Parabolina spinulosa [Matthew, 1892, p. 51].

Protopeltura acanthura tetracanthura [Matthew, 1892,
p. 53].

Conocephalites contiguus [Matthew, 1892, p. 58].

(Hor stratigraphic position and association, see p. 132.) Upper Cambrian: Shales

of Division 2b of Matthew’s Johannian at St. John, St. John County, New Brunswick.
*Lingulella (Lingulepis) starri.

308d [Matthew, 1894, p. 121]. (For stratigraphic position and association, see pp. 132 and 133.) Middle Cam-
brian: Sandstones of Division Clb2-4 of Matthew's section on Catons Island, in Long Reach, St. John
River, Kings County, New Brunswick.
*Botsfordia pulchra.

308e [Matthew, 1895a, p. 126]. (See 2fand 2g.) (For stratigraphic position and association, see p. 133.) Middle
Cambrian: Beds of Division Clb1 of the ‘‘Protolenus zone” [Matthew, 1895a, p. 108], on Hanford Brook,
7 St. John County, New Brunswick.
Botsfordia ceelata.

308f (references follow species). (For stratigraphic position and association, see p. 131.) Upper Cambrian: Lime-
stone lentiles in black shales of Division C3a of Matthew’s section, King Street, St.John, St. John County,
New Brunswick.
Orusia lenticularis [Matthew, 1903, p. 216].
Ctenopyge pecten [Matthew, 1903, p. 229].

308g [Matthew, 1897, p. 71]. (See 2u.) (For stratigraphic position and association, see p. 132.) Middle Cam-
brian: Shales of Division 1b3 or 1b4 of Matthew’s section on Long Island [Matthew, 1898, pp. 124 and 127],
Kennebecasis Bay, St. John County, New Brunswick.
*Trematobolus kempanum.

308h [U. S. National Museum]. (See 301g, 301w, and 3081.) (For stratigraphic position and association, see

p- 132.) Middle Cambrian: Shales of Division 1cl of Matthew’s section at Portland (now part of the city
of St. John), St. John County, New Brunswick.

Discinopsis gulielm1.

Acrothele matthew1.

Protorthis billingsi.

Protorthis latourensis.

Eocystites primeevus Billings.

Hyolithes micmac Matthew.

Microdiscus dawsoni Hartt.
Paradoxides eteminicus Matthew.
Paradoxides lamellatus Hartt.
Phradoxides micmac.

Ctenocephalus matthewi perhispidus.
Ptychoparia (Liostracus) tener (Hartt).

308i [U. S. National Museum]. (See 301g, 301k, 301w, and 308h.) For stratigraphic position and association,
see p. 132.) Middle Cambrian: Shales in Portland (now a part of the city of St. John), St. John County,
New Brunswick.
Protorthis billingsi.
Paradoxides sp.

240

809 (references follow species).

CAMBRIAN BRACHIOPODA.

(For stratigraphic position and association, see p. 144.) Passage beds between the

Cambrian and Ordovician: Ceratopyge limestone (zone 4 of Moberg and Segerberg) at Fogelsing, 5 miles
(8 km.) east of Lund, Province of Malméhus, Sweden.

Obolus (Bréggeria) salteri [Moberg and Segerberg, 1906,
desc. of PI. I].

Lingula? producta [Moberg and Segerberg, 1906, p. 63]=
Lingulella lepis.

Lingula? ordovicensis [Moberg and Segerberg,
p- 63]=Lingulella lepis.

*Acrotreta carinata [Moberg and Segerberg, 1906, desc. of
Pl. TIT].

*Acrotreta circularis [Moberg and Segerberg, 1906, p. 66].

Obolella (Acrotreta?) sagittalis [Moberg and Segerberg
1906, dese. of Pl. I]=Acrotreta sagittalis.

Capulus ceratopygarum [Moberg and Segerberg, 1906,
dese. of Pl. IIT]. q

Agnostus sidenbladhi urceolatus [Moberg and Segerbere,
1906, dese. of Pl. LV].

Agnostus fossulatus [Moberg and Segerberg, 1906, desc. of
Pl. IV].

Euloma ornatum [Moberg and Segerberg, 1906, desc. of
Pl. IV].

Harpides rugosus [Moberg and Segerberg, 1906, desc. of
Pl. Vj.

Ceratopyge latelimbata [Moberg and Segerberg, 1906, desc.
of Pl. VJ].

1906,

309a [Moberg and Segerberg, 1906, p. 62].

Symphysurus angustatus Debts and Segerberg
desc. of Pl. V].

Symphysurus elongatus [Moberg and Segerberg, 1906, desc.
of Pl. VJ.

Nileus armadillo [Moberg and Segerberg, 1906, desc. of
Pl. VI}.

Niobe insignis angustifrons [Moberg and Segerberg, 1906,
desc. of Pl. VI].

Niobe leviceps [Moberg and Segerberg, 1906, desc. of
Pl. VI].

Megalaspis intacta [Moberg and Segerberg, 1906, desc. of
Pl. VIj.

Orometopus elatifrons [Moberg and Segerberg, 1906, desc.
of Pl. VII).

Cyrtometopus sp. [Moberg and Segerberg, 1906, desc. of
Pl. VII).

Harpina (Harpes) excavata? [Moberg and Segerberg, 1906,
dese. of Pl. VII).

Crossoura parvula [Moberg and Segerberg, 1906, desc.
of Pl. VII]..

, 1906,

(For stratigraphic position and association, see p. 145.) Upper Cambrian:

Bryograptus slate (zone 2) at Fogelsang, 5 miles (8 km.) east of Lund, Province of Malméhus, Sweden.

Lingulella lepis.
Lingula? bryograptorum=Lingulella lepis.

309b [Moberg and Segerberg,

1906, p.63]. (For stratigraphic position and association, see p. 145.) Upper Cambrian:

Dictyograptus slate (zone 1) at Flagabro, Province of Malméhus, Sweden.

Lingula? corrugata=Lingulella lepis.

309¢ [Linnarsson, 1869a, p. 357; and U.S. National Museum].

(For stratigraphic position and association, see

p. 146.) Lower Cambrian: “‘Fucoid sandstone” at Billingen, east of Skara, Province of Skaraborg, Sweden.
& g

Obolella (Glyptias) favosa.
309d [Linnarsson, 1869a, p. 357].

(For stratigraphic position and association, see p. 146.) Lower Cambrian: ‘‘Fucoid

sandstone” at Lugnas, 23 miles (37 km.) northeast of Skara, Province of Skaraborg, Sweden.

*Obolella (Glyptias) favosa.
309e [U. S. National Museum].

(For stratigraphic position and association, see p. 145.) Upper Cambrian: Shales

of the Acerocare zone at Akarpsmélla, midway between Kageréd snd Réstanga, Province of Malméhus,

Sweden (J. C. Moberg).
Eoorthis christianiz.

309f [U.S. National Museum].
at Borgholm, Oeland Island, Sweden.
Acrothele (Redlichella) granulata

309h [U. S. National Museum].
Malmoéhus, Sweden.
Obolus (Bréggeria) salteri.
309i [U. S. National Museum].

(For stratigraphic position and association, see p. 146.) Middle Cambrian: Shale

(For stratigraphic position and association, see p. 145.) Upper Cambrian: Lime-
stones of the Dictyograptus flabelliformis zone at Fogelsang,

5 miles (8 km.) east of Lund, Province of

(See 390g.) (For stratigraphic position and association, see p. 145.) Upper

Cambrian: Limestones at Sandby, 6 miles (9.6 km.) east- SOHTINGEE of Lund, Province of Malméhus, Sweden.

Obolus (Bréggeria) salteri.
309j [U. S. National Museum].

(See 309m. and 320q.) (For stratigraphic position and association, see p. 145.)

Upper Cambrian: Shale at Alunbruk (alum works), southern part of Oeland Island, Sweden.

Obolus (Bréggeria) salteri.
3091 [U. S. National Museum].

(See 310h.) (For stratigraphic position and association, see p. 145.) Upper?

Cambrian: Shale collected somewhere in Sweden, exact locality unknown.

Obolus (Bréggeria) salteri.

, LOCALITIES.

309m [U. S. National Museum].

241

(See 309j.) (For stratigraphic position and association, see p. 145.) Upper Cam.

brian: Limestones forming 3c of the Olenus series at Alunbruk (alum works), southern part of Oeland

Island, Sweden (Schmalensee, 1899).
Orusia lenticularis.

810 (references follow species).

(For stratigraphic position and association, see p. 144.) Passage beds between the

Upper Cambrian and the Ordovician: Ceratopyge limestone (zone 4 of Moberg and Segerberg), Ottenby,

Oeland Island, Sweden.

Lingula producta [Moberg and Segerberg, 1906, p. 63]=
Lingulella lepis.

Lingula ordovicensis [Moberg and Segerberg, 1906, p. 63]=
Lingulella lepis.

Acrothele barbata [Moberg and Segerberg, 1906, p. 67J=
Acrothele ceratopygarum.

?Acrotreta circularis [Moberg and Segerberg, 1906, p. 66].

Acrotreta carinata [Moberg and Segerberg, 1906, p. 66].

Eoorthis christianiz [Moberg and Segerberg, 1906, desc. of
Pl. I11]=Eoorthis daunus.

EKostrophomena elegantula [Moberg and Segerberg, 1906,
desc. of Pl. IIT].

Lamanskya splendens [Moberg and Segerberg, 1906, desc.
of Pl. IIT].

Meristella difformis [Moberg and Segerberg, 1906, desc. of
Pl. IIT].

Agnostus sidenbladhi urceolatus [Moberg and Segerberg,
1906, dese. of Pl. IV].

Agnostus trinodus [Moberg and Segerberg, 1906, desc. of
Pl. IV].

Triarthrus angelini [Moberg and Segerberg, 1906, desc. of
Pl. IV].

Acerocare n. sp.? [Moberg and Segerberg, 1906, desc. of
Pl. IV].

Ceratopyge forficula [Moberg and Segerberg, 1906, desc. of
Pl. Vj.

Dikellocephalus bréggeri [Moberg and Segerberg, 1906,
dese. of Pl. V].

310a [U. S. National Museum].

Apatocephalus serratus [Moberg and Segerberg, 1906, desc.
of Pl. Vj.

Symphysurus angustatus [Moberg and Segerberg, 1906,
desc. of Pl. V].

Symphysurus breviceps [Moberg and Segerberg, 1906,
desc. of Pl. V].

Nileus armadillo [Moberg and Segerberg, 1906, desc. of
Pl. VI].

Niobe insignis [Moberg and Segerberg, 1906, desc. of Pl. VI].

Niobe leviceps [Moberg and Segerberg, 1906, desc. of
Pl. VI).

Niobe obsoleta [Moberg and Segerberg, 1906, desc. of
Pl. VI].

Megalaspis planilimbata [Moberg and Segerberg, 1906,
desc. of Pl. VII].

Tllznus oriens [Moberg and Segerberg, 1906, desc. of
Pl. VII).

Orometopus elatifrons? [Moberg and Segerberg, 1906, desc.
of Pl. VII].

Holometopus térnquisti [Moberg and Segerberg, 1906, desc.
of Pl. VIT].

Cy:tometopus primigenus [Moberg and Segerberg, 1906,
dese. of Pl. VII].

Cyrtometopus speciosus [Moberg and Segerberg, 1906,
desc. of Pl. VII]. ;

(For stratigraphic position and association, see p.145.) Upper Cambrian: Shales

of Olenus truncatus zone, Oeland Island, Sweden.

*Acrotreta conula.
Orusia lenticularis.
Olenus truncatus Briinn.

310b [U. S. National Museum].

(For stratigraphic position and association, see p. 145.) Middle Cambrian: Dark-

brown limestone at Borgholm, Oeland Island, Sweden.

Acrotreta schmalenseei.
Billingsella exporrecta.

310c [Wallerius, 1895, p. 66].

} These two species may not occur in the same bed.

(See 310p.) (For stratigraphic position and association, see p. 146.) Middle Cam-

brian: Limestone of the Paradoxides elandicus zone on Oeland Island, Sweden.

Acrotreta schmalenseei.

310d [U.S. National Museum].

(See 390i.) (For stratigraphic position and association, see p. 145.) Upper Cam-

brian: Ceratopyge slate at Borgholm, Oeland Island, Sweden (Schmalensee, 1899).

Obolus (Bréggeria) salteri.
Lingulella ferruginea.
Lingulella lepis.
*Acrothele borgholmensis.

310e [Moberg, 1892b, p. 115].

Acrotreta seebachi.
Eoorthis christianiz.
Orthoid.

(For stratigraphic position and association, see p. 146.) Lower Cambrian: Sandstone

bowlder on the beach between Ekerum and Stora Ror, on Oeland Island, Sweden.

*Acrothele sp. undt.
62667°—vou 51, pr 1—12——16

249 CGAMBRIAN BRACHIOPODA.

310f [Moberg, 1892b, p. 115]: (For stratigraphic position and association, see p. 146.) Lower Cambrian: Drift
blocks of glauconitic quartzitic sandstone west of Ekerum, Kalmar sheet (Geol. Survey Sweden), Oeland
Island, Sweden.
Micromitra (Paterina) undosa.
Acrothele sp. undt.
Discinella.

310g [Moberg, 1892b, p. 115]. (For stratigraphic position and association, see p. 146.) Lower Cambrian: Sand-
stone bowlders south of Stora Rér, on Oeland Island, Sweden.
Acrothele sp. undt.

310h [U. S. National Museum]. (See 3091.) (For stratigraphic position and association, see p. 145.) Upper?
Cambrian: Shale collected somewhere (probably Fogelsang) in the old Province of Skane, now the Provinces:
of Malméhus and Christianstad, Sweden.
Lingulella concinna.
Obolus (Bréggeria) salteri.
Billingsella exporrecta.

310i [U. S. National Museum]. (For stratigraphic position and association, see p. 145.) Passage beds between the
Middle Cambrian Paradoxides forchhammeri zone and the Upper Cambrian Olenus truncatus zone: Limestone
at Borgholm, Oeland Island, Sweden.

Acrotreta parvula.

Agnostus levigatus Dalman.

*Lingulella agnostorum.
Acrothele coriacea.

$10j [U. S. National Museum]. (For stratigraphic position and association, see p. 144.) Passage beds between the
Upper Cambrian and the Ordovician: Ceratopyge limestone at Borgholm, Oeland Island, Sweden.

Eoorthis wimani.

*Eostrophomena elegantula.

Lingulella lepis.
Eoorthis daunus.

310k [U. S. National Museum]. (For stratigraphic position and association, see p.145.) Upper Cambrian: Oeland
Island, Sweden.
*Lingulella sp. undt. a.

3101 [U.S. National Museum]. (See 8w, 320i, and 32ly.) (Forstratigraphic position and association, see p. 145.)
Middle Cambrian: In the Paradoxides forchhammeri zone at Andrarum, 20 miles (32 km.) northwest of Sim-
rishamn, Province of Christianstad, Sweden.

*Dicellomus sp. undt.

310m [Linnarsson, 1876, p. 16]. (See 3100.) (For stratigraphic position and association, see p. 146.) Middle
Cambrian: Arenaceous shales of the Paradoxides tessini zone on Oeland Island, Sweden.
Lingulella ferruginea.

310n [Moberg and Segerberg, 1906, p. 65]. (For stratigraphic position and association, see p. 145.) Upper Cam-
brian: In the ‘‘Obolus sandstone?” in Dalarne, Province of Kopparberg, Sweden.
Obolus triangularis.

3100 [U. S. National Museum]. (See 310m.) (For stratigraphic position and association, see p. 146.) Middle
Cambrian: Limestone in the Paradomides tessini zone at Borgholm, Oeland Island, Sweden.
Lingulella ferruginea.
Acrothele (Redlichella) granulata.

310p (references follow species). (See310c.) (For stratigraphic position and association, see p. 146.) Middle Cam-
brian: Limestone of the Paradoxides elandicus zone at Borgholm, Oeland Island, Sweden.
Lingulella ferruginea (U. 8. National Museum). d
Acrotreta socialis [Linnarsson, 1876, p. 18]=Acrotreta schmalenseei.

310q [U. S. National Museum]. (For stratigraphic position and association, see p. 145.) Middle Cambrian: Lime-
stone of the Agnostus levigatus zone at Lovened, Province of Skaraborg, Sweden.
Lingulella ferruginea.

310r [Westergard, 1909, p. 76]. (For stratigraphic position and association, see p. 145.) Upper Cambrian: Zone v
of the Ceratopyge slate at Ottenby, Oeland Island, Sweden. :
*A crotreta celandica.

310s [Westergard, 1909, p. 76]. (For stratigraphic position and association, see p. 145.) Upper Cambrian: Upper-
most part of the Alum slate in beds equivalent to the Ceratopyge slate, northern part of Oeland Island,
Sweden.
Acrotreta celandica.

LOCALITIES. 243

$10t [Westergard, 1909, p: 57]. (For stratigraphic position and association, see p. 145.) Upper Cambrian: Sub-
- zone ¢ of the Dictyograptus slate at Fogelsang, 5 miles (8 km.) east of Lund, Province of Malméhus, Sweden.
*Acrotreta sp. undt.

310u [Westergard, 1909, p. 77]. (For stratigraphic position and association, see p. 145.) Upper Cambrian: Sub-
zone ¢ of the Dictyograptus slate at Jerrestad, Province of Malméhus, Sweden.
Acrotreta sp.

310v [Westergard, 1909, p. 77]. (For stratigraphic position and association, see p. 145.) Upper Cambrian: Sub-
zone 6 of the Dictyograptus slate at Tosterup, 7.5 miles (12 km.) north-northeast of Ystad, Province of

Malméhus, Sweden.

Acrotreta sp. :

310w [Westergard, 1909, desc. of Pl. II]. (For stratigraphic position and association, see p. 144.) Passage beds
between the Upper Cambrian and the Ordovician: Zone ¢ at Grénhégen, Oeland Island, Sweden.
Lingulella lepis.

310x [Westergird, 1909, p. 76]. (For stratigraphic position and association, see p. 144.) Passage beds between
the Upper Cambrian and the Ordovician: The uppermost limestone stratum in beds equivalent to the
Ceratopyge limestone at Jerrestad, Province of Malméhus, Sweden.
*Obolus? inflatus.

$10y [Linnarsson, 1879, p. 25,and U. S. National Museum.] (For stratigraphic position and association, see p. 145.)
Middle Cambrian: Limestone at Kiviks Esperéd, Province of Malméhus, Sweden.
Lingulella ferruginea.

$10z [U. S. National Museum]. (For stratigraphic position and association, see p. 145.) Middle Cambrian: Lime-
stone at Brantevik, on the shore a little south of Simrishamn, Province of Christianstad, Sweden.
Lingulella ferruginea.
Billingsella exporrecta.

311 [Wiman, 1902, p.57]. (For stratigraphic position and association, see p. 146.) Middle? Cambrian: Drift bowlder
of coarse-grained, somewhat friable, glauconitic sandstone, No. 3, on Eggegrund Island, about 25 miles (40
km.) northeast of Gefle, Province of Gefleborg, Sweden.

*Obolus (Westonia) bottnicus. Aparchites? anderssoni.
Lingula sp. Hipponicharion matthewi.
Kutorgina?. Torellella levigata.
*Acrotreta eggegrundensis. : Olenellus?.

31la [Wiman, 1902, p. 57]. (For stratigraphic position and association, see p. 146.) Middle? Cambrian: Drift
bowlder of glauconitic sandstone at Norrskedika, a little northwest of Osthammar, Province of Stockholm,
Sweden. :
Acrotreta eggegrundensis.

311b [Wiman, 1902, p. 57]. (For stratigraphic position and association, see p. 146.) Middle? Cambrian: Drift
bowlder of bituminous sandstone, No. 2, on Biludden, about 20 miles (32.2 km.) east of Gefle, Province
of Gefleborg, Sweden.
*Acrotreta uplandica.

311e [Wiman, 1902, p. 57]. (For stratigraphic position and association, see p. 146.) Middle? Cambrian: Drift
bowlder of bituminous sandstone, No. 7, on Biludden, about 20 miles (32.2 km.) east of Gefle, Province
of Gefleborg, Sweden.
*Obolus (Westonia) wimani. Beyrichona gevalensis.
Lingula or Lingulella. Olenellus sp.
Torellella laevigata.

311d [Wiman, 1902, p. 57]. (For stratigraphic position and association, see p. 146.) Middle? Cambrian: Drift
bowlder of glauconitic sandstone south of Lumparstrémmen, Aland Island, Finland, Russia.
Acrotreta eggegrundensis.

31le [Wiman, 1902, p. 57]. (For stratigraphic position and association, see p. 146.) Middle? Cambrian: Drift
bowlder of rusty sandstone south of Lumparn, parish of Jomala, Aland Island, Finland, Russia.
Mickwitzia monilifera.
Obolus (Westonia) bottnicus?.

311 [Wiman, 1902, p. 57]. (For stratigraphic position and association, see p. 146.) Middle? Cambrian: Drift
bowlder of gray quartzitic sandstone at Slemmern, Mariehamn, Aland Island, Finland, Russia.
Mickwitzia monilifera.

244 CAMBRIAN BRACHIOPODA.

811g |Wiman, 1902, p. 57]. (For stratigraphic position and association, see p. 146.) Middle? Cambrian: Drift
bowlder of bituminous sandstone, No. 16, on Biludden, about 20 miles (32.2 km.) east of Gefle, Province
of Gefleborg, Sweden.
Obolus (Westonia) wimani.
Lingula sp.
Torellella levigata.

311h [Wiman, 1902, p. 57]. (For stratigraphic position and association, see p. 146.) Middle? Cambrian: Drift
bowlder of bituminous sandstone, No. 26, on Biludden, about 20 miles (32.2 km.) east of Gefle, Province
of Gefleborg, Sweden.
*Obolus (Westonia) balticus.

311i [Wiman, 1902, p. 57]. (For stratigraphic position and association, see p. 146.) Middle? Cambrian: Drift
bowlder of bituminous sandstone, No. 27, on Biludden, about 20 miles (32.2 km.) east of Gefle, Province
of Gefleborg, Sweden.
Obolus (Westonia) wimani.

311j [Wiman, 1902, p. 57]. (For stratigraphic position and association, see p. 146.) Middle? Cambrian: Drift
bowlder of bituminous sandstone, No. 28, on Biludden, about 20 miles (32.2 km.) east of Gefle, Province
of Gefleborg, Sweden.
Obolus (Westonia) alandensis.
Lingula or Lingulella.

311k [Wiman, 1902, p. 57]. (For stratigraphic position and association, see p. 146.) Middle? Cambrian: Drift
* bowlder of bituminous sandstone, No. 29, on Biludden, about 20 miles (32.2 km.) east of Gefle, Province
of Gefleborg, Sweden.
Obolus (Westonia) alandensis.
Torellella leevigata.

3111 [Wiman, 1902, p. 57]. (For stratigraphic position and association, see p. 146.) Middle? Cambrian: Drift
bowlder of bluish calcareous sandstone, No. 31, on Biludden, about 20 miles (32.2 km.) east of Gefle,
Province of Gefleborg, Sweden.
* Mickwitzia formosa.
Mickwitzia monilifera.

311m [Wiman, 1902, p. 57]. (For stratigraphic position and association, see p. 146.) Middle? Cambrian: Drift
bowlder of bituminous sandstone, No. 1, on Limén Island, about 12 miles (19.3 km.) east-northeast of Gefle,
; Province of Gefleborg, Sweden.
Obolus (Westonia) alandensis.
Beyrichona alta.
Torelletla levigata.

311n [Wiman, 1902, p. 57]. (For stratigraphic position and association, see p. 146.) Middle? Cambrian: Drift
bowlder of blue calcareous sandstone, No. 6, on Lim6n Island, about 12 miles (19.3 km.) east-northeast of
Gefle, Province of Gefleborg, Sweden.
*Acrotreta uplandica liméensis. Ellipsocephalus sp.
Acrotreta sp. Trilobite (not Olenellus).
Torellella levigata.

811lo [Wiman, 1902, p. 57]. (For stratigraphic position and association, see p. 146.) Middle? Cambrian: Drift
bowlder of bituminous sandstone, No. 1, on Skilstenarne Island, just west of Eggegrund Island, about
25 miles (40 km.) east-northeast of Gefle, Province of Gefleborg, Sweden.
Obolus (Westonia) balticus.

311p [Wiman, 1902, p. 57]. (For stratigraphic position and association, see p. 146.) Middle? Cambrian: Drift
bowlder of glauconitic sandstone, No. 1, at Héganis, parish of Bérstil, east of Osthammar, Province of
Stockholm, Sweden.
Lingula or Lingulella.
Acrotreta uplandica.

811q [Wiman, 1902, p. 57]. (For stratigraphic position and association, see p. 146.) Middle? Cambrian: Drift
bowlder of gray quartzitic sandstone at Ytterniset, Mariehamn, Aland Island, Finland, Russia.
Mickwitzia monilifera.

311r [Wiman, 1902, p. 57]. (For stratigraphic position and association, see p. 146.) Middle? Cambrian: Drift
bowlder of gray quartzitic sandstone at Granboda, Lemland, Aland Island, Finland, Russia.
Mickwitzia monilifera.

LOCALITIES. QA5)

311s [Wiman, 1902, p. 57]. (For stratigraphic position and association, see p. 146.) Middle? Cambrian: Drift
bowlder of gray quartzitic sandstone at Skarpnato, Aland Island, Finland, Russia.
Mickwitzia formosa.
Stenotheca sp.

311t [Wiman, 1902, p. 57]. (For stratigraphic-position and association, see p. 146.) Middle? Cambrian: Drift
bowlder of mottled calcareous sandstone at Ofverby, parish of Jomala, Aland Island, Finland, Russia.
Obolus (Westonia) balticus. Lingula or ibfweilala,
Obolus (Westonia) wimani. Ellipsocephalus latus.

311u [Wiman, 1902, p. 57]. (For stratigraphic position and association, see p. 146.) Middle? Cambrian: Drift
bowlder of blue calcareous sandstone at Séderarm lighthouse, near Norrtelje, Province of Stockholm,
Sweden.
Mickwitzia monilifera.

311v [Wiman, 1902, p. 68]. (For stratigraphic position and association, see p. 145.) Upper Cambrian: Drift
bowlder of Obolus sandstone, Ersholmen Island, parish of Bérstil, southeast of Oreerund, Province of
Stockholm, Sweden.
Obolus apollinis. \

311w [Wiman, 1902, p. 68]. (For stratigraphic position and association, see p. 145.) Upper Cambrian: Drift
bowlder of Obaties sandstone at Mariehamn, Aland Island, Finland, Russia.
Obolus apollinis,
Orthis sp.

311x [U.S. National Museum]. (For stratigraphic position and association, see p. 146.) Middle Cambrian: Com-
pact, fine-grained, quartzitic sandstone at Saltvik, Aland Island, Finland, Russia (Schmalensee, 1901).

*Obolus (Westonia) finlandensis.
Elipsocephalus (Liostracus) muticus Angelin.

81ly [Wiman, 1902, p. 57]. (For stratigraphic position and association, see p. 146.) Middle? Cambrian: Drift
bowlder of rusty sandstone at Ytternis, Slemmern, Aland Island, Finland, Russia.
*Obolus (Westonia) alandensis. Bradorona nitida.
Lingula or Lingulella. Trilobite (not Olenellus).

312 [U. S. National Museum]. (For stratigraphic position and association, see p. 138.) Lower Cambrian: Sand-
stones of 3d of the Waucoba Springs section [Walcott, 1908f, p. 187], east of Saline Valley road, east of
Waucoba Springs, Inyo County, Cal.
Trematobolus excelsis.
Cruziana.
Holmia rowei.

312a [U.S. National Museum]. (For stratigraphic position and association, see p. 138.) Lower Cambrian: Sand-
stones of 3b of the Waucoba Springs section [Walcott, 1908f, p. 187], east of the Saline Valley road, east
of Waucoba Springs, Inyo County, Cal.
Obolella vermilionensis. °
Trematobolus excelsis.

313 [U. S. National Museum]. (For stratigraphic position and association, see p. 139.) Upper Cambrian: Lime-
stone 0.75 mile (1.2 km.) east-northeast of McGill post office, White Pine County, Nev.
Micromitra (Paterina) crenistria. : Lingulella isse.
Lingulella desiderata. . Acrotreta idahoensis.

318a [U.S. National Museum]. (Compare 313d and 313f.) (For stratigraphic position and association, see p. 140.)
Middle Cambrian: Limestone at Schellbourne, Schell Creek Range, White Pine County, Nev.
Lingulella arguta?.

313b [U.S. National Museum]. (For stratigraphic position and association, see p. 139.) Middle Cambrian: Lime-
stone 3 miles (4.8 km.) north-northeast of Schellbourne, Schell Creek Range, White Pine County, Nev.
Micromitra (Paterina) crenistria.
Lingulella desiderata.
Acrotreta idahoensis alta.

318¢ [U. S. National Museum]. (For stratigraphic position and association, see p. 139.) Middle? Cambrian:
Limestone 12 miles (19.3 km.) west-southwest of Alpha Station, Eureka County, Nev.
Lingulella acutangula.
Lingulella desiderata.

246 CAMBRIAN BRACHIOPODA.

313d [U.S. National Museum]. (Compare 313a and 313f.) (For stratigraphic position and association, see p. 139.)
Lower Ordovician: Limestone at Schellbourne, Schell Creek Range, White Pine County, Nev.
*Obolus rotimdatus.

313e [U.S. National Museum]. (For stratigraphic position and association, seé p.139.) Middle Cambrian: Lime-
stone 2 miles (3.2 km.) west of Green’s ranch, White Pine County, Nev. (O. H. Hershey).
Lingulella arguta.
Linnarssonella girtyi.

313f [U.S. National Museum]. (Compare 313a and 313d.) (For stratigraphic position and association, see p. 139.)
Upper Cambrian: Limestone at Schellbourne, Schell Creek Range, White Pine County, Nev.
*Lingulella arguta.
*Lingulella manticula. }These species are probably from more than one horizon.
*Acrotreta pyxidicula. 5

318¢ [U.S. National Museum]. (For stratigraphic position and association, see p. 158.) Lower Cambrian: Lime-
stone at the southern end of the Timpahute Range, Groome district, near the line between Nye and Lin-
coln counties, Nev.
*Nisusia (Jamesella) erecta. Olenellus fremonti Walcott.
Billingsella sp. Peachella iddingsi (Walcott).
Callavia nevadensis Walcott.

313h [U.S. National Museum]. (For stratigraphic position and association, see p. 139.) Upper Cambrian: Sandy
shale on Hamburg Ridge, Eureka district [Hague, 1892, Atlas], Eureka County, Nev.
*Linnarssonella minuta.

313i [U. S. National Museum]. (For stratigraphic position and association, see p. 138.) Lower Cambrian: Lime-
stone collected at long. 117° 20’ W., lat. 38° N., in the western part of Esmeralda County, Nev.
Kutorgina perugata.

313} [Hall and Whitfield, 1877, pp. 205 and 206]. (Specimens in U.S. National Museum.) (Vor stratigraphic
position and association, see p. 139.) Upper Cambrian: Limestone in the Eureka district [Hague, 1892,
Atlas], Eureka County, Nev.
*Obolus discoideus.
*Obolus meera.
These species, in all probability, did not occur together; Hall and Whitfield give no further data, however,
concerning their occurrence.

318k [U. S. National Museum]. (See 214a and 214b.) (For stratigraphic position and association, see p. 139.)
Ordovician: Limestone in the White Pine district, White Pine (?) County, Nev.
Linnarssonella minuta. ;

314 (references follow species). (For stratigraphic position and association, see p. 140.) Middle Cambrian: Lime-
stone in Paradoxides zone, Chapple Arm, Trinity Bay, Newfoundland.

*Acrotreta misera [Billings, 1872b, p. 470]. *Anapolenus venustus [Billings, 1872b, p. 474].
*Aoraulos socialis [Billings, 1872b, p. 472]. *Paradoxides tenellus [Billings, 1872b, p. 476].
*Solenopleura communis [Billings, 1872b, p. 474]. *Paradoxides decorus [Billings, 1872b, p. 476].

314a [Whiteaves, 1878, p. 226]. (For stratigraphic position and association, see p. 140.) Upper Cambrian: Shales
on Kelleys Island, Conception Bay, Newfoundland.
*Lingulella billingsiana.

314b [Matthew, 1899e, p. 97]. (For stratigraphic position and association, see p. 141.) Lower Cambrian: Upper
limestone of Matthew’s Etcheminian at Smith Sound, Trinity Bay, Newfoundland.
*Kutorgina granulata.

314c [Billings, 1865a, p. 220]. (For stratigraphic position and association, see p. 140.) Lower Ordovician: Nodules
of white limestone belonging to Division P of Billings’s section at Cow Head, Newfoundland.
Syntrophia calcifera.
Bathyurus saffordi.

314d [Billings, Paleozoic fossils, vol. I].

LOCALITIES. 247

(For stratigraphic position and association, see p. 140.) Lower Ordovi-

cian: Limestone of Division P of the “Quebec group” 4 miles (6.4 km.) northeast of Portland Creek,

Newfoundland.
*QObolus cyane (p. 216).
*Lingulella iole (p. 215).
*Acrotreta gemma (p. 217).
*Orthis delicatula (p. 217).
Strophomena aurora (p. 218).
Camerella parva (p. 219).
Camerella varians (p. 220).
Nileus scrutator (p. 274).
Tileenus fraternus (p. 276).
*Harpides atlanticus (p. 281).
*Harpides concentricus (p. 282).
Shumardia glacialis (p. 283).

Cheirurus polydorus (p. 286).
Cheirurus sol (p. 288).
Amphion barrandei (p. 288).
Triarthrus fischeri (p. 291).
Telephus americanus (p. 291).
Encrinurus mirus (p. 292).
Remopleurides? schlotheimi (p. 294).
Ampyx normalis (p. 295).
*Ampyx rutilius (p. 296).
Ampyx semicostatus (p. 297).
Agnostus fabius (p. 298).
Agnostus galba (p. 297).

314e (references followspecies). (For stratigraphic position and association, see p.141.) Lower Cambrian: Lime-
stone at Topsail Head, Conception Bay, Newfoundland.

Micromitra (Paterina) bella [Billings, 1872b, p. 478].

Scenella reticulata [Billings, 1872b, p. 479].
Agraulos strenuus [Billings, 1872b, p. 473.]

Walcott [1886a, p. 150] adds the following species:

Salterella.
Micromitra (Paterina) labradorica?.

Stenotheca rugosa (Hall).
Protypus senectus parvulus.

314f [U.S. National Museum]. (For stratigraphic position and association, see p. 141.) Lower Cambrian: Lime-
stone of B7 of the section at Bonne Bay [Walcott, 1891b, p. 255], Newfoundland.

‘Obolella chromatica.
Micromitra (Paterina) labradorica.
Mesonacis vermontana (Hall).

Conocephalites.
Bathyurus.
Salterella.

314g [Billings, 1865b, p. 362]. (For stratigraphic position and association, see p. 140.) Lower Ordovician: A loose
piece of gray argillaceous limestone at Maiden Arm, Hare Bay, on the east side of the northern point of

Newfoundland.
*Obolus? murrayi.

314h [U.S. National Museum]. (For stratigraphic position and association, see p. 140.) Middle Cambrian: Shale
on Manuels Brook, Conception Bay, Newfoundland.

Acrotreta misera.

314i [U.S. National Museum]. (For stratigraphic position and association, see p. 140.) Upper Cambrian: Shale
picked up on beach in Smith Sound, Trinity Bay, Newfoundland (C. D. Walcott, 1899).

Ornsia lenticularis.

315 (references follow species). Middle? Cambrian: Limestone at Curramulka, Yorke Peninsula, South Australia.

*Micromitra (Paterina) etheridgei [Tate, 1892, p. 184].

Kutorgina peculiaris [Tate, 1892, p. 185].
*Nisusia compta [Tate, 1892, p. 185].

315a [Tate, 1892, p. 185]. Middle? Cambrian: Limestone at Parara, near Ardrossan, Yorke Peninsula, South

Australia.
*Kutorgina peculiaris.

$15b [Etheridge, 1905a, p. 249]. Middle? Cambrian: Limestone at Wirrialpa, Flinders Range, South Australia.

-*Eoorthis tatei.

315¢ [Etheridge, 1905, p. 250]. Middle? Cambrian: ‘‘Archzeocyathinz white limestone” at Wirrialpa, Flinders

Range, South Australia.
**Huenella etheridgei.

315d [Btheridge, 1905, p. 248, and U. 8. National Museum]. Lower? Cambrian: Limestone near Wirrialpa,
Flinders Range, South Australia.
*Obolella wirrialpensis.

316 [Davidson, 1871, p. 343]. (For stratigraphic position and association, see p. 135.) Lower Ordovician: Upper
Llandeilo (?) black shales at Dobbs Linn, near Moffat, in Dumiriesshire, Scotland.
*Acrotreta nicholsoni.

248 CAMBRIAN BRACHIOPODA.

816a [Davidson, 1883, p. 213]. (Forstratigraphic position and association, see p.135.) Lower Ordovician: Llandeilo
at Craighead, Ardmillan Brae, and Balcletchie, all three in the Girvan district of Ayrshire, Scotland.
Acrotreta nicholsoni.

316b [Davidson, 1883, p.211]. (Forstratigraphic position and association, see p. 136.) Middle Cambrian: At Cairn
Burn and Druidhill Burn, both in Dumfriesshire, Scotland.
Acrotreta sagittalis.

816¢ [Geol. Survey Scotland, M4197d; personal communication, J. Horne, 1910]. (for stratigraphic position and
association, see p. 136.) Lower Cambrian: Probably equivalent to those in band 6 or 7 of the section on the
north slope of Meall 4 Ghiubhais [Peach and Horne, 1907, p. 414], on the Bruachaig River, 2 miles (3.2 km.)
east-northeast of the Kinlochewe Hotel, Loch Maree, Ross-shire, Scotland.
*Lingulella zeus.
Olenellus lapworthi? Peach and Horne.

316d [Geol. Survey Scotland, M2646e, M2647e, and M4178d; personal communication, J. Horne, 1910]. (For

stratigraphic position and association, see p. 186.) Lower Cambrian: About 500 feet (152.5 m.) above the
provisional base of the Cambrian and 75 feet (23 m.) below what is believed to be the top of the Lower
Cambrian, in the shales forming 5 and 6 of the section given by Peach and Horne [1907, p. 414], in a small
burn on the north slope of Meall 4 Ghiubhais, 4 miles (6.4 km.) west-northwest of the Kinlochewe Hotel,
Loch Maree, Ross-shire, Scotland.

*Micromitra scotica.

Olenellus lapworthi? Peach and Horne.

317 [Davidson, 1883, p. 213]. Lower Ordovician: Coalpit Bay, County Down, Ireland.
Acrotreta nicholsoni.

81%a [Davidson, 1871, p. 340]. Middle Cambrian: At Bellewstown, County Meath, and at Balbriggan, County
Dublin, both in Ireland. ,
Acrotreta sagittalis?.

317b [Davidson, 1866, p. 58]. Middle Cambrian: Shales at Bellewstown, County Meath, Ireland.
Lingulella davisi.

318 [Davidson, 1869, p. 232]. (For stratigraphic position and association, see p. 135.) Upper Cambrian: Upper
Lingula flags at Penmain Pool, west of Dolgelly, Merionethshire, North Wales.
Orusia lenticularis.

318a [Davidson, 1868, p. 314]. (For stratigraphic position and association, see p. 135.) Upper Cambrian: Upper
Lingula flags at Criccieth, Carnarvonshire, North Wales.
Orusia lenticularis.

318b [Davidson, 1869, p. 232]. (For stratigraphic position and association, see p. 135.) Upper Cambrian: Upper
Lingula flags near Portmadoc, Carnarvonshire, North Wales.
Orusia lenticularis.

318c [Davidson, 1868, p. 310]. (For stratigraphic position and association, see p. 135.) Upper Cambrian: Lower
Lingula flags at the Rheider Waterfall Valley and at Gwytfynydd and other places near Dolgelly, North
Wales.
Acrotreta sagittalis.

818d (references follow species). (For stratigraphic position and association, see p. 136.) Middle Cambrian:
Sandstones in the middle portion of the Menevian at Porth-y-rhaw, St. Davids, South Wales.
Acrothele maculata [Davidson, 1871, p. 341].
*Orbiculoidea pileolus [Davidson, 1868, p. 316].
*Billingsella hicksi [Davidson, 1869, p. 230].

318e (references follow species). (For stratigraphic position and association, see p. 136.) Middle Cambrian: Lower
portion of the Menevian at Camlan, North Wales.
Lingulella ferruginea [Davidson, 1871, p. 337].
Acrothele maculata [Davidson, 1871, p. 341].
Orbiculoidea pileolus [Davidson, 1871, p. 345].

318f [Davidson, 1871, p.341]. (For stratigraphic position and association, seep. 1386.) Middle Cambrian: Lower
portion of the Menevian at Gwynfynydd, North Wales.
Acrothele maculata.

318g [Davidson, 1868, p. 310]. (For stratigraphic position and association, see p. 135.) Upper Cambrian: Lower
Lingula flags at Porth-y-rhaw, Pen-y-pleidiau, and several other localities near St. Davids, South Wales.
*A crotreta sagittalis.

LOCALITIES. 249

318h [U. S. National Museum]. (For stratigraphic position and association, see p. 136.) Middle Cambrian: Shales
in the Menevian at St. Davids, South Wales.
Lingulella ferruginea. Acrotreta sagittalis.
Acrothele maculata. Billingsella hicksi.

318i [U. S. National Museum]. (See 366c.) (For stratigraphic position and association, see p. 136.) Middle?
Cambrian: Red shales of the Caerfai group at St. Davids, South Wales.
Lingulella primzeva.

318j [Salter, 1866b, p. 340]. (For stratigraphic position and association, see p. 136.) Middle Cambrian: Black
shales of the Menevian group at Pen-y-pleidiau, St. Davids, South Wales. .
*Lingulella ferruginea.

318k [Davidson, 1871, p. 337]. (For stratigraphic position and association, see p. 136.) Middle Cambrian: In the
Menevian rocks at Tafern Helig, North Wales.
Lingulella ferruginea.

3181 [Davidson, 1871, p. 337]. (Forstratigraphic position and association, see p. 136.) Middle Cambrian: In the
Menevian rocks at the Waterfall Valley, near Maentwrog, North Wales.
Lingulella ferruginea.

318m [Davidson, 1866, p.57]. (For straticraphic position and association, see p. 135.) Upper Cambrian: Near the
base of the lower black slates at the Waterfall Valley, near Maentwrog, North Wales.
Lingulella davyisi.

318n [Davidson, 1871, p. 337]. (For stratigraphic position and association, see p. 136.) Middle Cambrian: Red
shales at the base of the Harlech grits at St. Davids, South Wales.
Lingulella ferruginea. :

3180 [Davidson, 1871, p. 337]. (For stratigraphic position and association, see p. 136.) Middle Cambrian: Red
shales at the base of the Harlech grits at Solva, St. Davids, South Wales.
Lingulella ferruginea.

318p (references follow species). (Forstratigraphic position and association, see p. 136.) Middle Cambrian: Sand-
stones in the middle portion of the Menevian at Ninewells, near St. Davids, South Wales.
Orbiculoidea pileolus [Davidson, 1871, p. 344].
*Billingsella hicksi [U. 8. National Museum and Davidson, 1869, p. 230].

318q [Davidson, 1871, pp. 344-345]. (For stratigraphic position and association, see p. 136.) Middle Cambrian:
Yellowish-gray beds in the Harlech group, on the road between Solva and Whitechurch, St. Davids, South
Wales.
Orbiculoidea pileolus?.

318r [Davidson, 1871, p. 344]. (Forstratigraphic position and association, see p. 136.) Middle Cambrian: Sand-
stones in the middle portion of the Menevian at Solva Harbor, St. Davids, South Wales.
Orbiculoidea pileolus. :

318s [Davidson, 1868, p. 314]. (For stratigraphic position and association, see p. 135.) Upper Cambrian: Upper
Lingula flags at Ogof-ddu Cliff, Carnarvonshire, North Wales. ‘
Orusia lenticularis.

218t [Davidson, 1868, p. 314]. (For stratigraphic position and association, see p. 135.) Upper Cambrian: Upper
Lingula flags at Penmorfa Church, Tremadoc, Carnarvonshire, North Wales.
Orusia lenticularis.

318u (references follow species). (For stratigraphic position and association, see p. 135.) Upper Cambrian
Upper Lingula flags at Gwerny-y-Barcud, North Wales.
Lingulella ferruginea [Davidson, 1868, p. 315].
Orusia lenticularis [Davidson, 1868, p. 314].

318v (references follow species). (For stratigraphic position and association, see p. 135.) Upper Cambrian:
Upper Lingula flags at Rhiwfelyn, North Wales.
Lingulella ferruginea [Davidson, 1868, p. 315].
Orusia lenticularis [Davidson, 1869, p. 232].

318w [U.S. National Museum]. (For stratigraphic position and association, see p. 135.) Upper Cambrian: Trema-
doc shale on Ramsey Island, St. Davids, South Wales.
Eoorthis carausii.

250 CAMBRIAN BRACHIOPODA.

319 [Geol. Survey Canada]. (See 319i; may be same locality.) Lower Ordovician: Limestone No. 1 of Billings’s
Point Levis section, Point Levis, Province of Quebec, Canada.
*EHikania ida.
*Acrotreta ovalis.

The following species are quoted from this locality by Billings, Paleozoic Fossils, vol. 1:

Metoptoma venillia (p. 88). *Dikellocephalus hisingeri (p. 196).
*Orthis ? apicalis (p. 301). *Dikellocephalus magnificus (p. 399).
*Acnostus canadensis (p. 397). *Dikellocephalus megalops (p. 408).
~*Aenostus orion (p. 397). *Dikellocephalus oweni (p. 402).
*Conocephalites zenkeri (p. 398). *Dikellocephalus pauper (p. 200).
*Arionellus cylindricus (p. 406). *Dikellocephalus planifrons (p. 401).
~*Arionellus subclavatus (p. 406). *Dikellocephalus selectus (p. 199).
*Menocephalus globosus (p. 408). *Dikellocephalus sesostris (p. 198).
*Menocephalus sedgwicki (p. 407). *Bathyurus armatus (p. 411).
*Dikellocephalus belli (p. 403). *Bathyurus capax (p. 409).
~*Dikellocephalus cristatus (p. 404). *Bathyurus dubius (p. 410).
319a (references follow species). Lower Ordovician: Levis shales, Point Levis, Province of Quebec, Canada.

*Lingulella irene [Billings, 1862b, p. 72]. *Acrothele levisensis (Geol. Survey Canada).
*Elkania desiderata [U. S. National Museum and Billings, | Lingulella sp. undt. (U.S. National Museum).

1862b, p. 70].

319b [U. S. National Museum]. Lower Cambrian: Conglomeratic limestones containing Olenellus?, St. Simon,
Rimouski (?) County, Province of Quebec, Canada.

Bicia gemma. Hyolithes americanus Billings.
Obolella crassa. Olenellus?.
*Obolella crassa elongata. Agraulos redpathi Walcott.

*Acrothele sp. undt. a.
Billingsella salemensis occurs at the same locality as the specimens mentioned above, but its stratigraphic posi-
tion is not known.

319c [Billings, 1862b, p. 69]. Ordovician: Shales at Cape Rouge, above Quebec, Province of Quebec, Canada.
Acrothele pretiosa.

319d [Billings, 1865a, p. 301]. Upper Cambrian: Limestone bowlder in Lower Ordovician conglomerate, Point
Levis, Quebec, Canada.
~*Lingulella iris.

319e (references follow species). Lower Cambrian: Sandy shales about 2 miles (3.2 km.) east of Swanton, Franklin
County, Vt. (See Locality 25a; the only known locality is nearly 2 miles east of Swanton, and Locality
319e has therefore been entered as 2 miles, though Billings gives it as 1.5 miles.)
Kutorgina cingulata [Billings, 1861b, p. 9].
*Nisusia festinata [Billings, 1861b, p. 10].
-*Swantonia antiquata [U. S. National Museum and Billings, 1861b, p. 11].

319f [U. S. National Museum]. Lower Ordovician: Drift bowlder of sandstone found near St. Albans, Franklin
County, Vt. The lithologic characters of the matrix in which this species was found point to the arenaceous
limestones of the Phillipsburg formation just north of the boundary between the United States and Canada
as the source of the bowlder.
~*Billingsella dice.

319g [Whitfield, 1884, p. 144]. Lower Cambrian: Shales at Parker’s quarry, near Georgia, Franklin County, Vt.
~*Billingsella orientalis.
Olenellus thompsoni. ne

319h [U.S. National Museum]. Lower Cambrian: Limestone bowlders in conglomerate at Metis, on the St. Law-
rence, below Quebec, Canada.
Billingsella salemensis. Olenellus? sp.
Hyolithellus micans (Billings). Ptychoparia metisensis Walcott.

819i [Billings, 1862b, p. 71, and Geol. Survey Canada]. (See 319; may be same locality.) Lower Ordovician:
Limestone at Point Levis, Province of Quebec, Canada.
-Elkania ida. :

LOCALITIES. 251

319j [U.S. National Museum]. (See 319k.) Lower Cambrian: Sandstone 50 feet (15 m.) above the base of the sec-
tion west of Parker’s quarry and about a mile (1.6 km.) from the shore of Lake Champlain, in the town-
ship of Georgia, Franklin County, Vt.

Botsfordia ceelata. Hyolithes sp.
Hyolithellus micans (Billings). Olenellus? sp.
Hyolithes americanus Billings. Ptychoparia trilineata (Emmons).

Hyolithes communis Billings.

319k [U. S. National Museum records]. (See 319j.) Lower Cambrian: Calcareous sandstone near the base of the
section west of Parker’s quarry, on cliff overlooking Lake Champlain, near Georgia, Franklin County, Vt.
Obolella crassa.

3191 [Billings, 1872a, p. 220,and U.S. National Museum.] Lower Cambrian: Limestone bowldersin conglomerate
at Trois Pistoles, Temiscouata County, on St. Lawrence River, below Quebec, Canada.
*Quebecia circe.

319m [Walcott, 1891b, p. 278]. Lower Cambrian: Shales of No.6 of the section at Parker’s quarry, near Georgia,
Franklin County, Vt.

Kutorgina cingulata.

Billingsella orientalis.

Nisusia festinata.

Nisusia festinata transversa.
*Paleophycus congregatus Billings.
*Paleeophycus incipiens Billings.
Phyllograptus (?) cambrensis Walcott. |

*Mesonacis vermontana (Hall).
*Olenellus thompsoni (Hall).
*Olenoides marcoui (Whitfield).
*Bathynotus holopyga (Hall).
Ptychoparia adamsi (Billings).
Ptychoparia vulcanus (Billings).
*Protypus hitchcocki (Whitfield).
Protypus senectus (Billings).
Protypus senectus parvulus (Billings).

*Climacograptus (?) emmonsi Walcott.
*Microdiscus parkeri.

319n [Billings, 1859, p. 432]. Ordovician: ‘‘Chazy formation” on the island of Montreal, in St. Lawrence River,
Canada.
*Obolus belli.

3190 [ Billings, 1859, p. 482]. Ordovician: “‘Chazy formation” near L’Original, on St. Lawrence River, Canada.
Obolus belli.

319p [Billings, 1859, p. 432]. Ordovician: ‘‘Chazy formation” on Allumette Island, in St. Lawrence River, Canada.
Obolus belli.

319q [U. S. National Museum records]. Upper Cambrian: Limestone 1 mile (1.6 km.) south-southwest of High-
gate Falls, Franklin County, Vt.
Obolus mera?.

319r [U. S. National Museum]. (See 319e and 25a.) Lower Cambrian: On the Bullard farm, about 2 miles (3.2
kin.) east of Swanton, Franklin County, Vt.
Rustella edsoni.
Olenellus thompsoni (Hall).

319s [U. S. National Museum]. Middle Cambrian: ‘‘St. Albans formation” at St. Albans, Franklin County, Vt.
Obolus matinalis?.
*Huenella vermontana.
Paradoxides sp.

319t [Billings, 1865a, p. 220]. Lower Ordovician: ‘‘Calciferous.sandrock” at St. Timothy, on the St. Lawrence,
near the head of the Beauharnois Canal, Province of Quebec, Canada.
Syntrophia calcifera.

319u [Billings, 186la, p. 320]. Lower Ordovician: ‘‘Calciferous sandrock” in the township of Edwardstown,
between Beauharnois and Lake Champlain, Province of Quebec, Canada.
Syntrophia calcifera.

319v [U. S. National Museum]. (See 319y.) Lower Cambrian: Sandy shale 2 miles (3.2 km.) east of Highgate
Springs, Franklin County, Vt. (C. D. Walcott, 1889).
Lingulella franklinensis.

319w [U. S. National Museum]. (See 319x.) Lower Cambrian: Limestone 1.25 miles (2 km.) north of Rutland,
Rutland County, Vt. (T. N. Dale).
Nisusia festinata.

252 CAMBRIAN BRACHIOPODA.

319x[U. 8. National Museum]. (See 319w.) Lower Cambrian: Limestone at the crossing of Hast Creek and Grove
Street, 1.25 miles (2 km.) north of Rutland, Rutland County, Vt. (A. F. Foerste, 1890).
Micromitra (Paterina) labradorica swantonensis.

319y [U. S. National Museum]. (See 26 and 319v.) Lower Cambrian: Sandstone 2 miles (3.2 km.) east-southeast
of Highgate Springs, Franklin County, Vt. (C. D. Walcott, 1889).
Micromitra (Paterina) labradorica swantorensis.
Stenotheca rugosa (Hall).
Ptychoparia sp.

$19z [U. S. National Museum]. (See 25a.) Lower Cambrian: Sandy limestone 2.5 miles (4 km.) east of Swanton,
Franklin County, Vt. (C. D. Walcott, 1897).
Micromitra (Paterina) labradorica swantonensis.

320 [Wallerius, 1895, p. 66]. (For stratigraphic position and association, see p. 145.) Middle Cambrian: Gudhem,
12.5 miles (20.1 km.) south-southeast of Skara, Province of Skaraborg, Sweden.
Acrotreta parvula.

320a [Wallerius, 1895, p. 66]. (For stratigraphic position and association, see p. 145.) Middle Cambrian:
Djupadal, 19 miles (30.6 km.) south-southeast of Skara, Province of Skaraborg, Sweden.
*Acrotreta parvula. :
Agnostus levigatus Dalman.

320b [U. S. National Museum]. (For stratigraphic position and association, see p. 145.) Middle Cambrian: Lime-
stones forming 2d of the Paradoxides zone, the Agnostus levigatus horizon, at Gudhem, 12.5 miles (20.1 km.)
south-southeast of Skara, Province of Skaraborg, Sweden.
Acrothele coriacea. *Billingsella exporrecta.
Acrothele (Redlichella) granulata. *Billingsella exporrecta rugosicostata.

320c [Wallerius, 1895, p. 66]. (For stratigraphic position and association, see p. 145.) Middle Cambrian: Andrarum
limestone at Andrarum, 20 miles (32 km.) northwest of Simrishamn, Province of Christianstad, Sweden.
Acrotreta schmalenseei.

320d [U. S. National Museum]. (For stratigraphic position and association, seep. 146.) Middle Cambrian: Hxsu-
lans limestone in the lower part of the Paradowides tessini zone at Fogelsing, 5 miles (8 km.) east of Lund,
Province of Malméhus, Sweden.
Acrotreta schmalenseei.

320e [U. S. National Museum]. (See 321q.) (For stratigraphic position and association, see p. 145.) Middle
Cambrian: Limestone at Munkesten, north of Hunneberg, Province of Skaraborg, Sweden.
Acrotreta schmalenseei.

320f [U. S. National Museum]. (See 8w, 3101, and 321y.) (For stratigraphic position and association, see p. 145.)
Middle Cambrian: Limestone at Andrarum, 20 miles (32 km.) northwest of Simrishamn, Province of Chris-
tianstad, Sweden.

Micromitra pusilla. Acrothele coriacea.
Micromitra (Iphidella) ornatell. Orusia lenticularis.

320g [U. S. National Museum]. (For stratigraphic position and association, see p. 145.) Middle Cambrian: Lime-
stones of the Paradoxides forchhammeri zone at Borgholm, Oeland Island, Sweden.
Acrothele coriacea.
Billingsella exporrecta.

320h [Grénwall, 1902, p. 39]. (For stratigraphic position and association, see p. 145.) Middle Cambrian: Shales
in the Paradovides tessini zone at Lovened, 19 miles (30.6 km.) south-southeast of Skara, Province of Skara-
borg, Sweden.
Acrothele intermedia.

320i [Grénwall, 1902, p. 39]. (For stratigraphic position and association, see p. 145.) Middle Cambrian: Limestones
of the Coronatus zone at Andrarum, 20 miles (32 km.) northwest of Simrishamn, Province of Christianstad,
Sweden.
Acrothele intermedia.

320j [Grénwall, 1902, p. 39]. (For stratigraphic position and association, see p. 145.) Middle Cambrian: Lime-
stones of the Coronatus zone at Gisléf, Province of Malmcéhus, Sweden.
Acrothele intermedia.

LOCALITIES. 253

320k (references follow species). (For stratigraphic position and association, see p. 145.) Middle Cambrian: Lime-
stones at Kiviks Esperéd, Province of Malméhus, Sweden.
Acrothele coriacea (U. 8. National Museum).
~Acrothele intermedia [Grénwall, 1902, p. 39].
The exact horizon from which the specimens of Acrothele coriacea were sibiteiiaedl 4 isnot known. Acrothele inter-
media was obtained from the Coronatus zone.

3201 (references follow species). (For stratigraphic position and association, see p. 146.) Middle Cambrian: Drift
blocks supposed to have come from the Paradowides wlandicus zone [Linnarsson, 1876, p. 6], at Lillviken,
near Oestersund, Province of Jemtland, Sweden.

*Obolus sp. undt. g [Linnarsson, 1876, p. 16]. Billingsella exporrecta [Linnarsson, 1876, p. 13].
Acrothele coriacea [Linnarsson, 1876, p. 23]. Billingsella lindstrémi [Linnarsson, 1876, p. 12].
~*Acrothele (Redlichella) granulata [Linnarsson, 1876,

p. 24]. (Referred to as “A. coriacea.’’)

320m (references follow species). (For stratigraphic position and association, see p. 145.) Middle Cambrian:
Limestones of the Paradovides forchhammeri zone at Kinnekulle, northeast of Lidképing, Province of Skara-
borg, Sweden.
Lingula or Lingulella[Linnarsson, 1876, p. 15]=Lingulella | Billingsella exporrecta [Linnarsson, 1876, p. 13].

ferruginea. Orthis aff. hicksi [Linnarsson, 1876, p. 14]=Billingsella
~*Acrothele coriacea [Linnarsson, 1876, p. 23]. exporrecta rugosicostata.
Acrotreta socialis [Linnarsson, 1876, p. 18]=Acrotreta | *Billingsella lindstrémi [U.S. National ingen and Lin-
schmalenseei. narsson, 1876, pp. 11, 12, and 33].

820n (references follow species). (For stratigraphic position and association, see p. 145.) Middle Cambrian: Lime-
stones of the Paradoxides forchhammeri zone at Lovened, Djupadal, 19 miles (30.6 km.) south-southeast of
Skara, Province of Skaraborg, Sweden.
~*Micromitra (Iphidella) ornatella [U. S. National Museum | Acrotreta socialis (U. S. National Museum).

and Linnarsson, 1876, p. 26]. *Billingsella exporrecta [U. S. National Museum and Lin-
Lingula or Lingulella [Linnarsson, 1876, p. 16]=Lingu-| narsson, 1876, pp. 13 and 33].
lella ferruginea. Billingsella exporrecta rugosicostata (U. S. National
~*TLingulella linnarssoni (U. S. National Museum). Museum).
Acrothele coriacea [U. 8. National Museum and Linunars- | Orthis aff. hicksi [Linnarsson, 1876, p. 14]=Billingsella
son, 1876, p. 23]. exporrecta rugosicostata.
_Acrotreta schmalenseei (U. 8. National Museum). Billingsella lindstrémi (U. S. National Museum).

$200 [Linnarsson, 1876, p. 23]. (For stratigraphic position and association, see p. 146.) Middle Cambrian: Lime-
stone band between the Holmia kjerulfi zone and the Paradomides tessini zone at Andrarum, 20 miles (32 km.)
northwest of Simrishamn, Province of Christianstad, Sweden.
_Acrothele coriacea.

$20p (references follow species). (For stratigraphic position and association, see p. 145.) Middle Cambrian: Lime-
stones of the Paradoxides forchhammeri zone at Sédra Méckleby, southern part of Oeland Island, Sweden.
Acrothele coriacea [Linnarsson, 1876, p. 23].
Billingsella exporrecta [Linnarsson, 1876, p. 13].
‘Orthis aff. hicksi [Linnarsson, 1876, p. 14]=Billingsella exporrecta rugosicostata.
-Billingsella lindstrémi [Linnarsson, 1876, p. 12].

320q [U. S. National Museum]. (See 309j.) (For stratigraphic position and association, see p. 145.) Middle Cam-
brian: Limestone forming 2c of the Paradoxides forchhammeri zone at Alunbruk (alum works), southern
part of Oeland Island, Sweden (Schmalensee, 1899).
-Acrothele coriacea. Agnostus.
Acrothele intermedia. Dolichometopus svecicus Angelin
-Billingsella lindstrémi.

820r [U. S. National Museum]. (For stratigraphic position and association, see p. 145.) Middle Cambrian: Lime-
stones of the Agnostus levigatus zone at Hunneberg, western boundary of the Province of Skaraborg, Sweden.
-Acrothele coriacea.

320s [Linnarsson, 1877, p. 374]. (For stratigraphic position and association, see p. 146.) Middle Cambrian: At St.
Fré, Oeland Island, Sweden.
Acrothele (Redlichella) granulata.

320t [Linnarsson, 1876, p. 24]. (For stratigraphic position and association, see p. 146.) Middle Cambrian: On the
river Billstain, parish of Hackas, Province of Jemtland, Sweden.
Acrothele (Redlichella) granulata.

254 CAMBRIAN BRACHIOPODA.

320u [Linnarsson, 1876, p. 25]. (For stratigraphic position and association, see p. 145.) Middle Cambrian: Strata.
with Agnostus lxvigatus at Ostra Rynninge, in Nerike, Sweden.
Micromitra pusilla.

320v [Linnarsson, 1876, p. 23]. (See 320z.) (For stratigraphic position and association, see p. 145.) Middle Cam-
brian: In the Paradoxides forchhammert zone at Lanna, Hjulsta, Vinala, and Vrana, all four in Nerike,
Sweden.
Acrothele coriacea.

320w [Holm, 1898, p. 148]. (For stratigraphic position and association, seep. 144.) Passage beds between the Upper
Cambrian and the Ordovician: Ceratopyge limestone at Gléte, in Herjeadalen, Province of Jemtland, Sweden.
Lingulella lepis.

320x [Linnarsson, 1876, p. 16; U. S. National Museum]. (For stratigraphic position and association, see p. 146.)
Lower Cambrian: In strata with Holmia kjerulfi at Andrarum, 20 miles (32 km.) northwest of Simrishamn,
Province ‘of Christianstad, Sweden.

*Lingulella nathorsti.
Holmia kjerulfi (Brégger).

320y (references follow species). (For stratigraphic position and association, see p. 145.) Middle Cambrian: Lime-
stones of the Paradomides forchhammeri zone at Gudhem, 12.5 miles (20.1 km.) south-southeast of Skara,
Province of Skaraborg, Sweden.
Micromitra (Iphidella) ornatella (U. S. National Museum). | Billingsella exporrecta [Linnarsson, 1876, p. 13].
Acrothele coriacea (U. S. National Museum). Billingsella lindstrémi (U. S. National Museum).

320z [Linnarsson, 1876, p.13]. (See 320v.) (For stratigraphic position and association, see p. 145.) Middle Cam-.
brian: Limestones of the Paradozxides forchhammeri zone at several places in Nerike, Sweden. .
Billingsella exporrecta.

321 [Wiman, 1902, p. 68]. (For stratigraphic position and association, see p. 145.) Upper Cambrian: Drift bowlders:
of Obolus sandstone, Nos. 1, 2, 4-6, 10-16, 18-20, 22-23, 25-29, on Fanton Island, parish of Bérstil,.
Province of Stockholm, Sweden.
Obolus apollinis.

321a [Wiman, 1902, p. 68]. (For stratigraphic position and association, see p. 145.) Upper Cambrian: Drift bowl-
ders of Obolus sandstone, Nos. 3 and 7, on Fanton Island, parish of Boérstil, Province of Stockholm,
Sweden.
Obolus apollinis.
Problematicum.

321b [Wiman, 1902, p. 68]. (For stratigraphic position and association, see p. 145.) Upper Cambrian: Drift.
bowlder of Obolus sandstone, No. 8, on Fanton Island, parish of Bérstil, Province of Stockholm, Sweden.
Obolus apollinis.
Hyolithes.

321¢ [Wiman, 1902, p.68]. (For stratigraphic position and association, seep. 145.) Upper Cambrian: Drift bowlder-
of Obolus sandstone, No. 17, on Fanton Island, parish of Bérstil, Province of Stockholm, Sweden.
Obolus apollinis.
Obolus (Schmidtia) obtusus?.

321d [Wiman, 1902, p. 68]. (For stratigraphic position and association, see p. 145.) Upper Cambrian: Drift bowlder-
of Obolus sandstone, No. 21, on Fanton Island, parish of Bérstil, Province of Stockholm, Sweden.
Obolus apollinis.
Obolus (Schmidtia) celatus orbiculatus.

321e [Wiman, 1902, p. 68]. (For stratigraphic position and association, see p. 145.) Upper Cambrian: Drift
bowlder of Ceratopyge slate, No. 1, on Biludden, about 20 miles (32.2 km.) east of Gefle, Province of
Gefleborg, Sweden.
Acrotreta cf. sagittalis.
Shumardia celandica Moberg?.
Conodont.

321f[Wiman, 1902, p. 68]. (For stratigraphic position and association, see p. 145.) Upper Cambrian: Drift bowlder
of Ceratopyge slate, No. 2, on Biludden, about 20 miles (32.2 km.) east of Gefle, Province of Gefleborg,.
Sweden.
Acrotreta cf. sagittalis.
Trilobite?.

LOCALITIES. 255

821g [Wiman, 1902, p. 68). (For stratigraphic position and association, see p. 145.) Upper Cambrian: Drift
bowlder of Ceratopyge slate, No. 3, on Biludden, about 20 miles (32.2 km.) east of Gefle, Province of
Gefleborg, Sweden.
Acrotreta cf. sagittalis. Trilobite?.
Shumardia celandica Moberg?. Conodont.

321h [Wiman, 1902,-p. 68]. (For stratigraphic position and association, see p. 145.) Upper Cambrian: Drift
bowlders of Ceratopyge slate, Nos. 4, 6, and 7; on Biludden, about 20 miles (32.2 km.) east of Gefle, Province
of Gefleborg, Sweden.
Acrotreta cf. sagittalis.
Conodont.

321i [Wiman, 1902, p. 68]. (For stratigraphic position and association, see p. 145.) Middle Cambrian: Drift
bowlders of Ceratopyge slate, Nos. 8 and 23, on Biludden, about 20 miles (32.2 km.) east of Gefle, Province
of Gefleborg, Sweden.
Acrotreta cf. sagittalis.
Discina? sp.

321j [Wiman, 1902, p. 68]. (or stratigraphic position and association, see p. 145.) Upper Cambrian: Drift
bowlder of Ceratopyge slate, No. 9, on Biludden, about 20 miles (32.2 km.) east of Gefle, Province of
Gefleborg, Sweden.
Acrotreta cf. sagittalis. Trilobite?.
Shumardia celandica Moberg?. Conodont.

321k [Wiman, 1902, p. 68]. (For stratigraphic position and association, see p. 145.) Upper Cambrian: Drift
bowlder of Ceratopyge slate, No. 12, on Biludden, about 20 miles (32.2 km.) east of Gefle, Province of
Gefleborg, Sweden.
Acrotreta cf. sagittalis.
Trilobite?.
Conodont.

8211 [Wiman, 1902, p. 68]. (For stratigraphic position and association, see p. 145.) Upper Cambrian: Drift
bowlder of Ceratopyge slate, No. 14, on Biludden, about 20 miles (32.2 km.) east of Gefle, Province of
Gefleborg, Sweden.

Lingulella lepis?.
Acrotreta cf. sagittalis.
Graptolite.

821m [Wiman, 1902, p. 68]. (For stratigraphic position and association, see p. 145.) Upper Cambrian: Drift
bow:ders of Ceratopyge slate, Nos. 17 and 27, on Biludden, about 20 miles (32.2 km.) east of Gefle, Province
of Gefleborg, Sweden.
Lingulella lepis?. Discina sp.
Acrotreta cf. sagittalis. Shumardia celandica Moberg.

821n [Wiman, 1902, p. 68]. (For stratigraphic position and association, see p. 145.) Upper Cambrian: Drift
bowlder of limestone (Ceratopyge slate horizon) at Trédje, in Gastrikland, Sweden.

Obolella sp. s Graptolite.

Acrotreta ef. sagittalis. Ceratopyge forficula Sars.
Acrotreta sp. Shumardia bottnica Wiman.
Orthis sp.

8210 [Wiman, 1902, p. 68]. (For stratigraphic position and association, see p. 145.) Upper Cambrian: Drift
bowlder cf Obolus sandstone, No. 9, on Fanton Island, parish of Bérstil, Province of Stockholm, Sweden.
Obolus apollinis.
Lingulella sp.

3821p [Wallerius, 1895, p. 67]. (For stratigraphic position and association, see p. 145.) Middle Cambrian: In
strata with Agnostus levigatus at Oarlfors, near the north end of Mount Billingen, Province of Wermland,
Sweden.
Billingsella exporrecta.

321q [U. S. National Museum]. (See 320e.) (For stratigraphic position and association, see p. 145.) Middle Cam-
brian: Limestones of the Paradowides forchhammert zone at Munkesten, north of Hunneberg, western
boundary of the Province of Skaraborg, Sweden (Schmalensee, 1899).
Acrothele coriacea.
Acrotreta schmalenseei.
Billingsella exporrecta.

256 CAMBRIAN BRACHIOPODA.

321r.¢ (For stratigraphic position and association, see p. 145.) Middle Cambrian: Limestones of the Paradomides
forchhammeri zone at Hunneberg, western boundary of the Province of Skaraborg, Sweden.
Billingsella exporrecta.

321s [U. S. National Museum]. . (For stratigraphic position and association, see p. 146.) Lower Cambrian; Brown
sandstone interbedded in gray sandstone at Sularp, near Lund, Province of Malméhus, Sweden.
Obolella lindstrémi.
*Obolella mobergi.

321t [U.S. National Museum]. (For stratigraphic position and association, see p. 145.) Middle Cambrian: Sand-
stone at Sularp, near Lund, Province of Malméhus, Sweden.
Billingsella lindstrémi.

$21u [U. S. National Museum]. (For stratigraphic position and association, see p. 145.) Middle Cambrian: Sand-
stone at Bjorkelunda, south of Simrishamn, Province of Christianstad, Sweden.
Billingsella lindstromi.

321v [U. S. National Museum]. (For stratigraphic position and association, see p. 146.) Lower Cambrian: Gray
sandstone of the Mesonacis torelli zone at Bjorkelunda, south of Simrishamn, Province of Christianstad,
Sweden.
*Obolella lindstrémy.
Obolella mobergi.
Mesonacis torelli Moberg.

$21x [U. S. National Museum]. (For stratigraphic position and association, see p. 145.) Upper Cambrian: Dictyo-
graptus slate at Alunbruk (alum works), southern part of Oeland Island, Sweden (Schmalensee, 1899).
Obolus (Bréggeria) salteri.
$21y [U. S. National Museum]. (See 8w, 3101, and 320f.) (For stratigraphic position and association, see p. 145.)
Middle Cambrian: Shale at Andrarum, 20 miles (32 km.) northwest of Simrishamn, Province of Christianstad,
Sweden.
Acrotreta sagittalis.

321z [U.S. National Museum]. (For stratigraphic position and association, see p. 145.) Middle Cambrian: Shales
at Fogels’ng, 5 miles (8 km.) east of Lund, Province of Malmcohus, Sweden.
Acrotreta sagittalis.

322 [U.S. National Museum]. (For stratigraphic position and association, see p. 152.) Middle Cambrian: Lime-
stone (stratigraphic position unknown) about 6 miles (9.6 km.) WES ASEUNTIESE of Liberty and 15 miles (24.2)
km.) west of Montpelier, Bear Lake County, Idaho.

Acrotreta pyxidicula.

$22a [U.S. National Museum]. (For stratigraphic position and association, see p. 152.) Middle Cambrian: Lang-
ston limestone near Paris, Bear Lake County, Idaho (R. 8. Spence).
*Acrotreta idahoensis sulcata.
Microdiscus.
Ptychoparia, 2 sp.
323 [Wiman, 1902, p. 66]. (For stratigraphic position and association, see p. 144.) Passage beds between the
Upper Cambrian and the Ordovician: Phyllograptusslate and Ceratopyge limestone in the Christiania region,
Norway. 5
Acrotreta sagittalis.

328a [Wiman, 1902, p. 66]. (For stratigraphic position and association, see p. 145.) Upper Cambrian: Ceratopyge
slate in the Christiania region, Norway.
Acrotreta sagittalis.
Lingulella lepis.
323b [U.S. National Museum]. (For stratigraphic position and association, see p. 146.) Middle Cambrian: Lime-
stone of Paradoxides welandicus zone at Windjuelandet, Ringsaker, Province of Hedemarken, Norway.
Acrotreta schmalenseei.

328c [Brogger, 1882, p. 44]. (For stratigraphic position and association, see p. 144.) Passage beds between the
Upper Cambrian and the Ordovician: Ceratopyge limestone in the Christiania region, Norway.
Lingulella lepis.

323d [Christiania University Mineral Institute collections]. (For stratigraphic position and association see p. 144.)
Passage beds between the Upper Cambrian and the Ordovician: Ceratopyge limestone (Etage 3ay of Brég-
ger) at Christiania, Norway. :

Acrotreta seebachi.

a The authority for the citation of this locality was mislaid and could not be traced in time for insertion in this volume.

LOCALITIES. 257

328e [Christiania University Mineral Institute collections]. (For stratigraphic position and association, see p. 144.)
Passage’ beds between the Upper Cambrian and the Ordovician: Ceratopyge limestone (Etage 3ar of Brégger)
at Engervik, in Asker, in the Christiania region, Norway.

Acrotreta seebachi. *

Obolus (Bréggeria) salt ori f These may not be from the same bed.

$23f[Brogger, 1882, pp. 16-17]. (A lowerhorizon than 323h.) (Forstratigraphic position and association, see p. 144.)
Passage beds between the Upper Cambrian and the Ordovician: Lower part of the Ceratopyge limestone at
Vestfossen, 10 miles (16.1 km.) west-southwest of Christiania, Norway.

Lingulella lepis. Dikellocephalus angusticauda Angelin.
Obolus (Bréggeria) salteri. Nileus limbatus Brégeger.

Acrotreta socialis var.?=Acrotreta seebachi. Niobe obsoleta Linnarsson.

Eoorthis christianize=Hoorthis daunus. Amphion primigenus Angelin.
Triarthrus angelini Linnarsson. Cheirurus foveolatus Angelin.
Parabolinella rugosa Brégger. Bellerophon (?) norvegicus Brégger.
Ceratopyge forficula Sars. Orthoceras atavus Brégger.

323g [Christiania University Mineral Institute collections]. (Hor stratigraphic position and association, see p. 144.)
Passage beds between the Upper Cambrian and the Ordovician: Ceratopyge limestone (Etage 3a7 of Brégger)
at Vaekker6, in the Christiania region, Norway.

Acrotreta seebachi.

$23h [Brogger, 1882, p.17]. (A higher horizon than 323f.) (For stratigraphic position and association, see p. 144.)
Passage beds between the Upper Cambrian and Ordovician: Blue Ceratopyge limestone at Vestfossen, 10
miles (16.1 km.) west-southwest of Christiania, Norway.

. Lingulella lepis. Conophrys pusilla Sars.
Lingula sp. Dikellocephalus serratus Sars and Boeck.
Obolus (Bréggeria) salteri. Symphysurus aneustatus Sars and Boeck.
*Acrothele ceratopygarum (U.S. National Museum also). | Niobe insignis Linnarsson.
Acrotreta sagittalis var. Niobe obsoleta Linnarsson.
Acrotreta socialis var.=Acrotreta seebachi. Megalaspis cf. stenorachis Angelin.
Eoorthis christianize=Hoorthis daunus. Harpides rugosus Sars and Boeck.
Agnostus sidenbladhi Linnarsson. Remopleurides dubius Linnarsson.
Triarthrus angelini Linnarsson. Holometopus (?) elatifrons Angelin.
Ceratopyge forficula Sars.

323i [Brégger, 1882, desc. of Pl. X]. (For stratigraphic position and association, see p. 144.) Passage beds between
the Upper Cambrian and the Ordovician: Phyllograptus slate at Krekling, in Sandsviir, Norway.
Obolus (Brégegeria) salteri.

323] [Brogger, 1882, p. 44]. (Forstratigraphic position and association, see p. 144.) Passage beds between the Upper
Cambrian and the Ordovician: Ceratopyge limestone at Tosterup, 7.5 miles (12 km.) north-northeast of
Ystad, Province of Malméhus, Sweden.
‘Obolus (Bréggeria) salteri.

323k [Brogger, 1882, p. 44]. (For stratigraphic position and association, see p. 145.) Upper Cambrian: Ceratopyge
slate at Tosterup, 7.5 miles (12 km.) north-northeast of Ystad, Province of Malméhus, Sweden.
‘Obolus (Bréggeria) salteri.

$23 1 (references follow species). (For stratigraphic position and association, see p. 145.) Upper Cambrian: Htage
2b at Toien, about 1 mile (1.6 km.) northeast of Christiania, Norway.
-Orusia lenticularis [U. S. National Museum and Brégger, 1882, p. 48].
Parabolina spinulosa [Brégger, 1882, p. 48]. :

328m (references follow species). (Hor stratigraphic position and association, see p.145.) Upper Cambrian: Etage
2b at Oslo, about 1 mile (1.6 km.) southeast of Christiania, Norway.
-Orusia lenticularis [U. S. National Museum and Brégger, 1882, p. 4].
Parabolina spinulosa [Brégger, 1882, p. 4].

328n [Brogger, 1882, p. 48]. (For stratigraphic position and association, see p. 145.) Upper Cambrian: Etage 2b
at Vestfossen, 10 miles (16.1 km.) west-southwest of Christiania, Norway.
Orusia lenticularis.
Peltura scarabeoides.

3280 [Brogger, 1882, p. 4]. (For stratigraphic position and association, see p. 145.) Upper Cambrian: Etage 2b in
the city of Christiania, Norway.
-Orusia lenticularis.
Parabolina spinulosa.
62667°—vot 51, pr 1—12——_17

258 CAMBRIAN BRACHIOPODA.

323p (references follow species). (For stratigraphic position and association, seep. 145.) Upper Cambrian: Etage
2b at Slemmestad, in Réken, about 3 miles (4.8 km.) southwest of Christiania, Norway.
Orusia lenticularis [U. 8. National Museum and Brégger, 1882, p. 4].
Parabolina spinulosa [Brégger, 1882, p. 4].

323q [Brogger, 1882, p. 101]. (Kor stratigraphic position and association, see p. 145.) Upper Cambrian: Sines 2b
at Kartveit, in the Christiania region, Norway.
Orusia lenticularis.
Parabolina spinulosa.

323r [Brogeger, 1882, p. 4]. (For stratigraphic position and association, see p. 145.) Upper Cambrian: Etage 2b at
Krekling, in Sandsvar, Norway
Orusia lenticularis.
Parabolina spinulosa.

323s [Brégger, 1882, p. 4]. (For stratigraphic position and association, see p. 145.) Upper Cambrian: Htage 2b at
Gjégrefos, in Sandsvar, Norway.
Orusia lenticularis.
Parabolina spinulosa.

323t [Brogeer, 1882, p. 4]. (For stratigraphic position and association, see p. 145.) Upper Cambrian: Btage 2b in
Hedemarken, east of Lake Mjésen (Midésen), about 40 miles (64 km.) north-northeast of Christiania, Norway.
Orusia lenticularis. ;
Parabolina spinulosa.

328u [Brégger, 1882, p. 4]. (For stratigraphic position and association, see p. 145.) Upper Cambrian: Etage 2b
at Oxna (Oksna), valley of Glommen River, eastern Norway.
Orusia lenticularis.
Parabolina spinulosa.

323v [Davidson, 1869, p. 231]. (For stratigraphic position and association, see p. 145.) Upper Cambrian: At Ege-
berg (about 1.5 miles (2.4 km.) southeast of Christiania?), Norway.
*Orusia lenticularis.

328w (references follow species). (For stratigraphic position and association, see p. 145.) Upper Cambrian: Black
argillaceous shale of ‘‘Etage 3a8” at Christiania, Norway.
Obolus sp. (U. S. National Museum).
Obolus (Bréggeria) salteri (Univ. Mineral Inst., Christiania, Norway).
*Hoorthis wimani (U. 8. National Museum).

323x [U. S. National Museum]. (For stratigraphic position and association, see p. 149.) Upper Cambrian: Cera-
topyge slate at Russelékken, near Christiania, Norway.
*Hoorthis christianie.

323y [U. S. National Museum]. (For stratigraphic position and association, see p. 145.) Upper Cambrian: Cera-
topyge slate at Téien, about 1 mile (1.6 km.) northeast of Christiania, Norway.
Eoorthis christianize.

323z [U.S. National Museum]. (For stratigraphic position and association, see p. 144.) Passage beds between the
Upper Cambrian and the Ordovician: Ceratopyge limestone at Téien, about 1 mile (1.6 km.) northeast of
Christiania, Norway.
*Hoorthis daunus.

324 [Kjerulf, 1873, pp.73and 83]. (For stratigraphic position and association, see p. 146.) Lower Cambrian: Green
shales with interbedded calcareous sandstone at Tomten, in Ringsaker, near Lake Mjosen, Province of
Hedemarken, Norway.

Lingulella sp. (U. S. National Museum). Holmia kjerulfi (Brégger).
Obolella mobergi. Arionellus.
Obolella (Glyptias) favosa.

324a [U.S. National Museum]. (For stratigraphic position and association, see p. 146.) Middle Cambrian: Shales
of Etage lc [Brégger] at Skrena, Skiensdalen, Norway (W. C. Brégger, 1877).
Acrothele coriacea.

324b [U. S. National Museum]. (For stratigraphic position and association, see p. 146.) Middle Cambrian: Shales
of Etage 1c [Brégger] at Krekling, in Sandsviar, Norway (W. C. Brogger, 1877).
Acrothele coriacea. |
Agnostus nudus.

259

324c [U. S. National Museum]. (For stratigraphic position and association, see p. 145.) Middle Cambrian: Shales
of Etage 1d [Brogeer] at Krekling, in Sandsviir, Norway (W. C, Brogger, 1877).
Micromitra (Iphidella) ornatella.
Acrothele coriacea.

LOCALITIES.

324d.¢ (Forstratigraphic position and association, see p. 145.) Middle Cambrian: At Windjuelandet, Ringsaker,
Province of Hedemarken, Norway.
Lingulella ferruginea.

325 (references follow species). (For stratigraphic position and association, see p. 131.) Upper Cambrian: Arena-
ceous shales, possibly from the horizon of the Peltwra fauna (Division C3b), on McAdam shore, Hast Bay,
east of Bras d’Or Lake, in southeastern Cape Breton, Nova Scotia.

’

*Obolus (Westonia) escasoni [Matthew, 1903, p. 208].
*Aonostus trisectus germanus [Matthew, 1903, p. 221].
*Aonostus trisectus ponepunctus [Matthew, 1903, p. 221].

Ctenopyge pecten [Matthew, 1903, p. 230].
Parabolina dawsoni [Matthew, 1903, p. 224].
Peltura scarabeeoides [Matthew, 1903, p. 230].

*Spherophthalmus fletcheri [Matthew, 1903, p. 228].

325a (references followspecies). (For stratigraphic position and association, see p.131.) Middle Cambrian: Shales
of Division O2c of Matthew’s [1903, p. 49] Bretonian on the eastern slope of the valley of McNeil Brook,
on the road to Trout Brook, in the Mira River valley, eastern Cape Breton, Nova Scotia.
*Lingulella flumenis [Matthew, 1903, p. 190]. *Acrotreta cf. socialis [Matthew, 1903, p. 184]—Acrotreta
*Lingulella rotunda [Matthew, 1903, p. 199]. sp. undt.

325b [Matthew, 1903, desc. of Pl. XV]. (For stratigraphic position and association, see p. 131.) Upper Cambrian:
Sandy shales of Division C3a of Matthew, Escasonie shore, East Bay, east of Bras d’Or Lake, in southeastern
Cape Breton, Nova Scotia.
*Lingulella levis grandis.

$25¢ [U.S. National Museum]. (For stratigraphic position and association, see p. 132.) Middle Cambrian: Sand-
stone on the shore of Bras d’Or Lake, eastern Cape Breton, Nova Scotia.
Lingulella rotunda.

326 [U. S. National Museum]. Lower Ordovician: Limestone pebbles on the beach on the northern shore of
Marthas Vineyard, Mass. 7
Obolus (Westonia) rogersi.
Lingulella bella.

326a [Grabau, 1900, p. 613]. Lower Ordovician: Limestone pebbles in a Carboniferous conglomerate north of
Fall River, Bristol County, Mass.
Obolus (Westonia) rogersi. Obolus (Lingulobolus) spissus.

Obolus (Lingulobolus) affinis. Scolithus linearis Haldemann.

326b [Grabau, 1900, p. 617]. Middle Cambrian: Braintree slate, below high tide, about 100 feet (30.5 m.) east
of the quarry at East Braintree, Abington quadrangle (U.S. G. S.), Norfolk County, Mass.
*Acrothele gamagei.

$26c [Boston Society Natural History; casts in U.S. National Museum]. Lower Cambrian: “Nahant limestone,”
Pulpit Rock, Nahant, Essex County, Mass.
*Acrothele woodworthi.

326d [Grabau, 1900, p. 610].
Obolella atlantica.
Obolella crassa.
Scenella reticulata Billings.
Platyceras primeevum Billings.
Stenotheca abrupta (Shaler and Foerste).
Stenotheca curvirostra (Shaler and Foerste).
Hyolithes quadricostatus (Shaler and Foerste).
Hyolithes americanus Billings.

326e [Grabau, 1900, p. 610].
Norfolk County, Mass.
Obolella atlantica.
Urotheca pervetus Matthew.
Olenellus (Holmia) bréggeri (Walcott)=Callavia crosbyi
Walcott.
Olenellus sp. Burr=Callavia burri Walcott.
Olenellus (Mesonacis) asaphoides Emmons?=Callavia
crosby1 Walcott.

Lower Cambrian: ‘‘Station 2,’ near North Attleboro, Bristol County, Mass.
Orthotheea emmonsi (Ford).

Aristozoe?.

Olenellus walcotti (Shaler and Foerste).
Microdiscus bellimarginatus (Shaler and Foerste).
Microdiscus lobatus (Hall).

Strenuella strenua (Billings).

Ptychoparia? attleborensis (Shaler and Foerste).

Lower Cambrian: Dark purplish siliceous shales on Pearl Street, North Weymouth,

Metadoxides magnificus? Matthew=Callavia crosbyi Wal-
cott.

Microdiscus cf. helena Walcott.

Strenuclla strenua (Billings).

Trails.

a The authority for the citation of this locality was mislaid and could not be traced in time for insertion in this volume.

260 CAMBRIAN BRACHIOPODA.

326f (references follow species). Lower Cambrian: One-half mile (0.8 km.) south of North Weymouth [Burr,
1900, p. 42], Norfolk County, Mass.

Opolella atlantica [Burr, 1900, p. 47]. Metadoxides magnificus? [Burr, 1900, p. 46]=Callavia
Obolella sp. [Burr, 1900, p. 48]. crosbyi Walcott.
Olenellus (Holmia) bréggeri [Burr, 1900, p. 43]=Callavia | Agraulos (Strenuella) strenuus nasutus [Burr, 1900, p. 46].
crosbyi Walcott. Microdiscus cf. helena [Burr, 1900, p. 47].
Olenellus (Mesonacis) asaphoides [Burr, 1900, p. 45]=Cal- | Leperditia cf. solitaria [Burr, 1900, p. 47].
lavia crosbyi Walcott. Urotheca pervetus [Burr, 1900, p. 48].

Olenellus sp. [Burr, 1900, p. 45]=Callavia burri Walcott. | Orthotheca cylindrica [Burr, 1900, p. 48].

326g (references follow species). Lower Cambrian: Limestones at Hast Point, Nahant, Essex County, Mass.
Micromitra (Paterina) bella [Grabau, 1900, p. 618]. ;
Obolella crassa [Grabau, 1900, p. 620].

327 [U. S. National Museum]. Upper Cambrian: Arenaceous limestone east of Gold Camp, Caballos Mountains,
Sierra County, N. Mex. (W. T. Lee, 1905).
Obolus sinoe. Lingulella acutangula?.
Obolus sinoe?. : Eoorthis desmopleura.
Obolus (Westonia) stoneanus.

$27a [U. S. National Museum]. Upper Cambrian: Arenaceous limestone about 500 feet (152 m.) above the base
of the.Cambrian, in McKinley Canyon, Caballos Mountains, Sierra County, N. Mex. (W. T. Lee, 1905).
Obolus (Westonia) stoneanus.

327b [U.S. National Museum]. Upper Cambrian: Arenaceous limestone near the base of the section on the south
side of Cerro Cuchillo, Caballos Mountains, Sierra County, N. Mex. (W. T. Lee, 1905).
Obolus (Westonia) stoneanus.

327c¢[U.S. National Museum]. Upper Cambrian: Arenaceous limestone in the Caballos Mountains, Sierra County,
N. Mex. (W. Lindgren, 1905). ;
Obolus (Westonia) stoneanus.

328 [Whitfield, 1882, p. 172]. Upper Cambrian: Upper layers of the “‘St. Croix sandstone”’ near the north end of
Devils Lake, Sauk County, Wis.
*Syntrophia barabuensis.

328a [U. S. National Museum]. Upper Cambrian: ‘‘St. Croix sandstone” 4 miles (6.4 km.) north of Winfield,
Jefferson County, Wis.
Lingulella similis.

328b [Sardeson, 1896, p. 95]. Upper Cambrian: St. Lawrence formation at Osceola, Polk County, Wis. .
Obolus (Westonia) aurora.

328¢ [U. S. National Museum]. Upper Cambrian: “‘St. Croix sandstone” at Alma, Buffalo County, Wis.
Dicellomus politus.
Billingsella coloradoensis.
Ptychoparia diademata (Hall).

328d [Whitfield, 1882, p. 171]. Upper Cambrian: ‘‘St. Croix sandstone”’ at Berlin, Green Lake County, Wis.
Billingsella coloradoensis.

328e [U. S. National Museum]. Middle Cambrian: ‘‘St. Croix sandstone” at St. Croix Falls, Polk County, Wis.
(See p. 159.)
Obolus matinalis.
Lingulella (Lingulepis) acuminata.
*Acrotreta signalis.
328f [Hall, 1863, p. 128]. Upper Cambrian: Sandstone at the falls of St. Croix River, Polk County, Wis.
‘Obolus (Westonia) stoneanus.

328g (references follow species). Middle Cambrian: “St. Croix sandstone,’’ Wisconsin shore of Mississippi River,
near Trempealeau, Trempealeau County, Wis. (See p. 159.)
Lingulella ampla (U. S. National Museum). Conocephalites chippewaensis [Hall, 1863, p. 134].
Dicellomus politus [Hall, 1863, p. 134]. Hyolithes primordialis [Hall, 1863, p. 134].
Conocephalites iowensis [Hall, 1863, p. 134].
328h [Owen, 1852, p. 583,and U.S. National Museum]. Upper Cambrian: Silico-calcareous layers of Flb of Owen’s
‘section at the falls of the St. Croix, Polk County, Wis.
*¥Obolus matinalis.
Lingulella (Lingulepis) acuminata.

LOCALITIES. 261

$281 [U. S. National Museum]. Upper Cambrian: “‘St. Croix sandstone”’ 0.33 mile (0.5 km.) west of the rail-
way station, Lodi, Columbia County, Wis.
Finkelnburgia osceola.

” on Willow River, near Hudson, St.

$28] [U. S. National Museum]. Upper Cambrian: “‘St. Croix sandstone
Croix County, Wis.

Obolus mickwitzi.

328k [Whitfield, 1877, p.51]. Upper Cambrian: “‘St. Croix sandstone ’’ at Roche 4 Cris Bluff, Adams County, Wis.
*Syntrophia primordialis.

3281 [U. S. National Museum]. (See 328i.) Upper Cambrian: “St. Croix sandstone”? near Lodi, Columbia.
County, Wis.
Obolus (Westonia) aurora.

328m [U. S. National Museum]. Upper Cambrian: Sandstone 1 mile (1.6 km.) south of Osceola, Polk County,
Wis. (F. W. Sardeson, 1891).
Obolus (Westonia) stoneanus.

328n[U. S. National Museum]. Upper Cambrian: “St. Croix sandstone’’ 2 miles (3.2 km.) south of Osceola,
Polk County, Wis.
Lingulella similis.

3828p [U. S. National Museum]. (See 85x.) Upper Cambrian: “‘St. Croix sandstone” at Mazomanie, Dane:
County, Wis. (J. Hall).
Obolus (Westonia) aurora.

$28q [U. S. National Museum]. Upper Cambrian: “‘St. Croix sandstone ”’ in quarry at Ableman, Sauk County,
Wis. (J. F. James, 1889).
Eoorthis remnicha.

329 [Hague, 1877, p. 405]. (For stratigraphic position and association, see p. 149.) MiddleCambrian: Green shales
in a canyon about 7 miles (11.2 km.) north of Brigham (near the village of ‘‘Calls Fort’’ [Hague, 1877,
p. 405]), Boxelder County, Utah.
*Obolus (Westonia) ella. Ptychoparia quadrans (Hall and Whitfield).
Olenoides wasatchensis (Hall and Whitfield). Dikellocephalus gothicus=Olenoides wasatchensis.

329a [U. S. National Museum]. (For stratigraphic position and association, see p. 148.) Upper Cambrian: Lime-
stone on Ute Peak, in the Wasatch Mountains, east of Cache Valley, Cache County, Utah.
Syntrophia nundina?.

829b [U.S. National Museum]. (For stratigraphic position and association, see p. 155.) Middle Cambrian: Thin-
bedded limestone collected by the Wheeler survey in Utah.
Dicellomus politus.

329c [U. S. National Museum]. (For stratigraphic position and association, see p. 151.) Middle Cambrian: In
Weber Canyon, about 2.5 miles (4 km.) northeast of Peterson, Morgan County, Utah.
Obolus (Westonia) ella.

$29d [U.S. National Museum]. (For stratigraphic position and association, see p. 154.) Upper Cambrian: Lime-
stone near Fish Spring, Fish Spring Range, Juab County, Utah.
Acrotreta pyxidicula.

329e [U.S. National Museum]. (For stratigraphic position and association, see p. 158.) Middle Cambrian: Shales
in East Canyon, above Ophir, Oquirrh Range, Tooele County, Utah (40th Parallel Survey).
Obolus (Westonia) ella.

330 [Hall, 1851, p. 204]. Upper Cambrian: Sandstone on Taquamenon Bay, Chippewa County, Mich.
Lingulella (Lingulepis) acuminata.

330a [Hall, 1851, p. 204]. Upper Cambrian: Sandstone on Escanaba River, northern Michigan.
Lingulella (Lingulepis) acuminata.

330b [U. S. National Museum]. Upper Cambrian: Sandstone at Iron Mountain, Dickinson County, Mich. (W. 8.

Bayley, 1902). :

Lingulella (Lingulepis) acuminata.

331 [U.S. National Museum]. Upper Cambrian: Rogersville shale 1 mile (1.6 km.) south of Fletcher, Russell

County, Va.
Obolus lamborn*

262 CAMBRIAN BRACHIOPODA.

332 [Kayser, 1883, p. 35]. Upper Cambrian: Limestone at Saimaki, Liaotung, China.
*Obolus? sp. undt. f.
Lingulella davisi.

332a [Kayser, 1883, p. 34]. Upper Cambrian: At Taling, Liaotung, China.
*Hoorthis linnarssoni.

333 (references follow species). (For stratigraphic position and association, see p. 158.) Middle Cambrian:
Shales on the dump of the Abe Lincoln mine, near Pioche, Lincoln County, Nev.
Micromitra pannula [Pack, 1906, p. 296]. Bathyuriscus howelli [Pack, 1906, p. 297].
Obolus (Westonia) ella [Pack, 1906, p. 295]. Bathyuriscus productus [Pack, 1906, p. 297].
Lingulella genei [Pack, 1906, p. 295]=Wingulella dubia. | Zacanthoides typicalis [Pack, 1906, p. 299].
Eocystites longidactylus [Pack, 1906, p. 294].

333a (references follow species). (For stratigraphic position and association, see p. 158.) Middle Cambrian:
Shales on the dump of the Himon mine, near Pioche, Lincoln County, Nev.
Obolus (Westonia) ella [Pack, 1906, p. 295]. Bathyuriscus productus [Pack, 1906, p. 297].
Bathyuriscus howelli [Pack, 1906, p. 297]. Ptychoparia piochensis [Pack, 1906, p. 298].

333b (references follow species). (See 7k.) (Forstratigraphic position and association, see p. 158.) Middle Cam-
brian: Shales on the dump of the Halfmoon mine, near Pioche, Lincoln County, Nev.
Obolus (Westonia) ella [Pack, 1906, p. 295]. Ptychoparia kempi [Pack, 1906, p. 298].
Bathyuriscus howelli [Pack, 1906, p. 297]. Zacanthoides typicalis [Pack, 1906, p. 299].
Ptychoparia piochensis [Pack, 1906, p. 298]. Zacanthoides grabaui [Pack, 1906, p. 300].

334 (references follow species). (For stratigraphic position and association, see p. 145.) Middle Cambrian:
Limestones of Paradoxides forchhammeri zone on Bornholm Island, Denmark.
Acrotreta socialis [Wallerius, 1895, p. 66]=Acrotreta schmalenseei.
Acrotreta socialis [Linnarsson, 1876, p. 18]=Acrotreta schmalenseei.

334a [Grénwall, 1902, p. 39]. (For stratigraphic position and association, see p. 146.) Middle Cambrian: Lime-
_ stones of the Conocoryphe exsulans zone at Borregaard, Bornholm Island, Denmark.
Acrothele intermedia.

334b [Gronwall, 1902, p. 40]. (For stratigraphic position and association, see p. 145. Middle Cambrian: Andrarum
limestone at Borregaard, Bornholm Island, Denmark.
Acrothele coriacea.

334¢ [Grénwall, 1902, p. 40]. (For stratigraphic position and association, see p. 146.) Middle Cambrian: In the
Paradoxides tessini zone at Borregaard, Bornholm Island, Denmark.
Acrothele coriacea.

334d [Grénwall, 1902, p. 40]. (For stratigraphic position and association, see p. 146.) Middle Cambrian: In the
zone with Agnostus parvifrons at Borregaard, Bornholm Island, Denmark.
Acrothele coriacea.

334e [Grénwall, 1902, p. 40]. (For stratigraphic position and association, seep. 145.) Middle Cambrian: Andrarum
limestone at Laesad, Bornholm Island, Denmark.
Acrothele coriacea.

334f [U. S. National Museum]. (For stratigraphic position and association, see p. 145.) Middle Cambrian: Lime-
stone on Bornholm Island, Denmark. .
Acrothele coriacea.

334g [Seebach, 1865, pp. 340 and 341]. (For stratigraphic position and association, see p. 145.) Middle Cambrian:
On Bornholm Island, Denmark.

*Acrotreta socialis. Agnostus bituberculatus.
Paradoxides. Agnostus? punctuosus.
Agnostus pisiformis Linnarsson. Anomocare difforme Angelin.

334h [U. S. National Museum]. (See 16h.) (For stratigraphic position and association, see p. 145.) Middle Cam-
brian: Limestones of the Paradowides forchhammeri zone at Borregaard, Bornholm Tsland, Denmark (University
of Copenhagen).
Acrothele coriacea.
Acrotreta sagittalis.

335a. [U. S. National Museum]. (See 360b.) Passage beds between the Cambrian and the Ordovician: Red-
dish sandstone on Cement Creek, 3 miles (4.8 km.) north of Hot Springs and 8 to 10 miles (12.8 to 16.1 km.)
southeast of Crested Butte, Ouray County, Colo.
*Obolus loperi.

WARE ELL AAMC ERG OR EM a

LOCALITIES. 263

336 [F. Schmidt, personal communication, 1906]. (For stratigraphic position and association, see p. 143.) Ordo-
vician: Hchinosphexrites limestone, horizon Cla, at Popowka, near St. Petersburg, Russia.
*Acrotreta subconica.

336a (referencesfollow species). (For stratigraphic position and association, see p. 143.) Upper Cambrian: Obolus
sandstone at Podolova (Putalova?), on Ijora (Ischora) River, Government of St. Petersburg, Russia.
Obolus apollinis [Hichwald, 1860, p. 926].
Obolus apollinis ingricus [Hichwald, 1860, p. 926].
Keyserlingia buchi [Hichwald, 1860, p. 914].

336b [Eichwald, 1860, p. 925]. (For stratigraphic position and association, see p. 143.) Upper Cambrian: Obolus
sandstones on Odensholm Island, about 55 miles (88.6 km.) west of Reval, Government of Esthonia, Russia.
Obolus apollinis.

836c [Eichwald, 1860, p. 926]. (For stratigraphic position and association, see p. 143.) Upper Cambrian: Obolus
sandstone at Reval, Government of Esthonia, Russia.
Obolus apollinis.
Obolus apollinis ingricus.

336d [Eichwald, 1860, p. 929]. (For stratigraphic position and association, see p. 143.) Passage beds between the
Upper Cambrian and the Ordovician: Orthoceratite limestone at Reval, Government of Esthonia, Russia.
Obolus (Acritis) antiquissimus.

836e (references follow species). (For stratigraphic position and association, see p. 143.) Passage beds between
the Upper Cambrian and the Ordovician: Orthoceratite limestone, at Pulkowa, near St. Petersburg, Russia.
Obolus (Acritis) antiquissimus [Hichwald, 1860, p. 929].
Siphonotreta unguiculata [Hichwald, 1860, p. 916].
Siphonotreta verrucosa [Hichwald, 1860, p. 916].

836f [Hichwald, 1860, p. 927]. (For stratigraphic position and association, see p. 143.) Passage beds between the
Upper Cambrian and the Ordovician: In the pyroxene-bearing sands in the Orthoceratite limestone beds
at Reval, Government of Esthonia, Russia.
Obolus (Mickwitzella) siluricus.

836g (references follow species). (For stratigraphic position and association, see p. 143.) Ordovician: Limestone
in the vicinity of Zarskoe Selo, Government of St. Petersburg, Russia.
*Volborthia recurva [Kutorga, 1848, p. 278].

Siphonotreta unguiculata [Kutorga, 1848, p. 265]. | Mnese spcialesl mney moe se wioen Hino enme West,

$36h [U.S. National Museum]. (Forstratigraphic position and association, see p. 143.) Upper Cambrian: Ungulite
grit at Baltischport, Esthonia, Russia.
*Schizambon? esthonia.

336i [Mickwitz, 1896, p. 147]. (For stratigraphic position and association, see p. 144.) Upper Cambrian: Sand-
stone below the Obolus conglomerate proper at Reval, Government of Hsthonia, Russia.
Obolus triangularis.

836j [U.S. National Museum]. (For stratigraphic position and association, see p. 143.) Upper Cambrian: Obolus
sandstone at Staroja Ladoga, Government of Novgorod, Russia.
Obolus apollinis maximus.

336k [Hichwald, 1860, p. 925]. (For stratigraphic position and association, see p. 143.) Upper Cambrian: Obolus
sandstone on the bank of Volkhof (Wolchow) River, east of St. Petersburg, Russia.
Obolus apollinis.

3361 [Eichwald, 1860, p. 925]. (For stratigraphic position and association, see p. 143.) Upper Cambrian: Obolus
sandstone on the bank of Sjass (Sias) River, near Lake Ladoga, Government of St. Petersburg, Russia.

Obolus apollinis.

336m [Hichwald, 1860, p. 925]. (For stratigraphic position and association, see p. 143.) Upper Cambrian: Obolus
sandstone at Baltischport, about 30 miles (48 km.) west of Reval, Government of Esthonia, Russia.
Obolus apollinis.

336n [de Verneuil, 1845, p. 289]. (For stratigraphic position and association, see p. 143.) Upper Cambrian: On
Ijora (Ischora) River, Government of St. Petersburg, Russia.
*Keyserlingia buchi.

3360 [U. S. National Museum]. (For stratigraphic position and association, see p. 148.) Upper Cambrian: Ungu-
lite grit, Koporje, Government of St. Petersburg, Russia.
Obolus (Schmidtia) celatus.
Helmersenia ladogensis.
Keyserlingia buchi.

264 CAMBRIAN BRACHIOPODA.

336p [U. S. National Museum]. (For stratigraphic position and association, see p. 148.) Upper Cambrian: Ungu-
lite grit, Kunitz, Government of Pskow, Russia.
Obolus (Schmidtia) celatus. Helmersenia ladogensis.
Obolus sp. : Keyserlingia buchi.

336q [Jeremejew, 1856, pp. 73 and 80]. (For stratigraphic position and association, see p. 143.) Upper Cambrian:
Ungulite sandstone near Ladoga, Government of St. Petersburg, Russia.
*Helmersenia ladogensis.

336r [Mickwitz, 1896, p. 137]. (For stratigraphic position and association, see p. 143.) Upper Cambrian: Obolus
sandstone in the entire region between the Volkhof (Wolchow) and Sjass (Sias) rivers on the east and.
Baltischport on the west, governments of Novgorod, St. Petersburg, and Esthonia, Russia.
Obolus apollinis.

336s (references follow species). (For stratigraphic position and association, see p. 143.) Upper Cambrian: Obolus
sandstone at Narwa, Government of Esthonia, Russia.
Obolus apollinis (U. S. National Museum).
Obolus apollinis ingricus [Eichwald, 1843, p. 146].

336t [Eichwald, 1843, p. 146]. (Forstratigraphic position and association, see p. 143.) Upper Cambrian: Obolus
sandstone at Wiems, 5 miles (8 km.) north-northeast of Reval, Government of Esthonia, Russia.
Obolus apollinis.
Obolus apollinis ingricus.

336u [Eichwald, 1860, p. 925]. (For stratigraphic position and association, see p. 143.) Upper Cambrian: Obolus
sandstone on the bank of Louga (Luga) River, southwest of St. Petersburg, Russia.
Obolus apollinis. :

336v [Gagel, 1890, desc. of Pl. I]. (For stratigraphic position and association, see p. 143.) Ordovician: Echino-
spherites limestone at Reval, Government of Esthonia, Russia.
Siphonotreta unguiculata.

336w (references follow species). (For stratigraphic position and association, see p. 143.) Ordovician: Near Paw-
lowsk, near St. Petersburg, Russia.
Siphonotreta unguiculata [Hichwald, 1840, p. 140 (26)].
Siphonotreta verrucosa [Eichwald, 1840, p. 141 (27)].

336x [de Verneuil, 1845, p. 287]. (For stratigraphic position and association, see p. 143.) Ordovician: In the
Archangel quarry, on Volkhof (Wolchow) River, east of St. Petersburg, Russia.
Siphonotreta unguiculata.

336y [U.S. National Museum]. (For stratigraphic position and association, see p. 143.) Passage beds between the
Upper Cambrian and the Ordovician: Glauconite limestone at Popowka, near St. Petersburg, Russia.
Siphonotreta unguiculata.
Siphonotreta verrucosa.

336z [Schmidt, 1861, pp. 218 and 248]. (For stratigraphic position and association, see p. 143.) Passage beds
between the Upper Cambrian and the Ordovician: Orthoceratite limestone (‘‘Vaginatenkalk”) at Narwa,
Government of Esthonia, Russia.
Siphonotreta unguiculata.

337 [Schmidt, 1861, pp. 218 and 248]. (For stratigraphic position and association, see p. 143.) Passage beds
between the Upper Cambrian and the Ordovician: Orthoceratite limestone (‘‘Vaginatenkalk”) at Erras,
85 miles (137 km.) east of Reval, Government of Esthonia, Russia.
Siphonotreta unguiculata.

337a [Schmidt, 1861, pp. 218 and 248]. (For stratigraphic position and association, see p. 143.) Passage beds
between the Upper Cambrian and the Ordovician: Orthoceratite limestone (‘‘Vaginatenkalk”) at Kusal,
25 miles (40 km.) east of Reval, Government of Hsthonia, Russia.
Siphonotreta unguiculata.

337b [Schmidt, 1861, pp. 218 and 248]. (For stratigraphic position and association, see p. 143.) Passage beds
between the Upper Cambrian and the Ordovician: Orthoceratite limestone (‘‘Vaginatenkalk”) at Reval,
Government of Esthonia, Russia.
*Siphonotreta unguiculata.@

337¢ [Schmidt, 1861, pp. 218 and 248]. (For stratigraphic position and association, see p. 148.) Passage beds
between the Upper Cambrian and the Ordovician: Orthoceratite limestone (‘‘ Vaginatenkalk”) on Odens-
holm Island, 55 miles (88.6 km.) west of Reval, Government of Esthonia, Russia.
Siphonotreta unguiculata.

a May be the type locality. Hichwald [1829, p. 274] gives it as ‘‘ limestone at Reval.’’

LOCALITIES. . 265

337d [Schmidt, 1861, p. 218]. (For stratigraphic position and association, see p.143.) Ordovician: ‘‘Brandschie-
fer” at Salla, near Erras, 85 miles (137 km.) east of Reval, Government of Esthonia, Russia.
Siphonotreta unguiculata.

837e [Schmidt, 1861, p. 218]. (For stratigraphic position and association, see p. 143.) Ordovician: ‘‘Jewesche-
Schicht” at Altenhof, near Péddrus, 55 miles (88.6 km.) east of Reval, Government of Esthonia, Russia.
Siphonotreta unguiculata.

$37f [Schmidt, 1861, pp. 218 and 248]. (For stratigraphic position and association, see p. 143.) Passage beds:
between the Upper Cambrian and the Ordovician: Orthoceratite limestone (‘‘Vaginatenkalk”) at Tiirsel,
15 miles (24.2 km.) west of Narwa, Government of Esthonia, Russia.
Siphonotreta verrucosa. f

337g [Schmidt, 1861, pp. 218 and 248]. (For stratigraphic position and association, see p. 143.) Passage beds
between the Upper Cambrian and the Ordovician: Orthoceratite limestone (‘‘ Vaginatenkalk”) at Chudleigh,
25 miles (40 km.) west of Narwa, Government of Esthonia, Russia.
Siphonotreta verrucosa.

337h [Hichwald, 1860, p. 929]. (For stratigraphic position and association, see p. 143.) Passage beds between the-
Upper Cambrian and the Ordovician: Orthoceratite limestone near Reval, Government of Esthonia, Russia.
Obolus (Acritis) antiquissimus.

837i [Schmidt, 1861, p. 218]. (For stratigraphic position and association, see p. 143.) Passage beds between the.
Upper Cambrian and the Ordovician: ‘“‘Green sand” at Baltischport, Government of Esthonia, Russia.
Obolus (Mickwitzella) siluricus.

337j [Fr. Schmidt, personal communication, 1908]. (For stratigraphic position and association, see p. 148.) Ordo-
vician: Zone BIIla or BIIIf, characterized by Asaphus raniceps, a little above the zone with Asaphus
expansus, in the Orthoceratite limestone at Obookhoy (Obuchow), on Volkhof (Wolchow) River, Govern-
ment of St. Petersburg, Russia. ;
Volborthia recurva.

337k [Hichwald, 1860, p.916]. (For stratigraphic position and association, see p. 143.) Passage beds between the
Upper Cambrian and’ the Ordovician: Orthoceratite limestone on the banks of Volkhof (Wolchow) River,
near Lake Ladoga, near St. Petersburg, Russia.
Siphonotreta unguiculata.

3371 [Eichwald, 1860, p.916]. (For stratigraphic position and association, see p. 143.) Passage beds between the
Upper Cambrian and the Ordovician: Orthoceratite limestone at Baltischport, west of Reval, Government of
Esthonia, Russia. :
Siphonotreta unguiculata.

337m [Eichwald, 1860, p.916, and U.S. National Museum]. (For stratigraphic position and association, see p. 143.)
Passage beds between the Upper Cambrian and the Ordovician: Orthoceratite limestone at Popowka, near
St. Petersburg, Russia.
Siphonotreta unguiculata.
Siphonotreta verrucosa.

338 [U.S. National Museum]. (See 29a.) Lower Cambrian: Limestone at Schodack, northeastern corner of Cox-
sackie quadrangle (U.S. G. S.), Rensselaer County, N. Y.
Acrotreta sagittalis taconica.

338a [U. S. National Museum]. Lower Cambrian: Limestone in the northeast section of Whitehall township,,
Whitehall quadrangle (U.S. G. S.), Washington County, N. Y.
Acrotreta sagittalis taconica.

338b [U. S. National Museum]. (See 29.) Lower Cambrian: Limestone on Kinderhook Creek, near Stock-
port paper mill, Kinderhook quadrangle (U.S. G. 8.), Columbia County, N. Y.
Acrotreta sagittalis taconica.

838c [U. S. National Museum]. (See 33.) Lower Cambrian: Limestone at Rock Hill schoolhouse, near North
Greenwich, Cambridge quadrangle (U. 8S. G. S.), Washington County, N. Y.
Acrotreta sagittalis taconica.

338d [U. S. National Museum]. (See 36; may be same locality.) Lower Cambrian: Limestone 1 mile (1.6 km.)
south of Shushan, Cambridge quadrangle (U.S. G. S.), Washington County, N. Y.
Acrotreta sagittalis taconica.

ao ; se species in the s ;
Eyllpmesalls, aplenty. | These species may not occur in the same bed

338e [U. S. National Museum]. Lower Cambrian: Limestone a little west of North Greenwich, Cambridge quad-
rangle (U.S. G. 8.), Washington County, N. Y.
Acrotreta sagittalis taconica.

266 CAMBRIAN BRACHIOPODA.

338i [U. S. National Museum]. Lower Cambrian: Limestone near Argyle, 8 miles (12.8 km.) north of Greenwich,
Cambridge quadrangle (U. 8S. G. S.), Washington County, N. Y.
Acrotreta sagittalis taconica.

838g [U. S. National Museum]. Lower Cambrian: Limestone in the town of Greenwich, Cambridge quadrangle
(U.S. G.S.), Washington County, N. Y.
Acrotreta sagittalis taconica.

338h [U. S. National Museum]. (See Walcott, 1888, pp. 316 and 317, for section.) Lower Cambrian: Limestone
on the summit of Bald Mountain, about 2 miles (3.2 km.) northwest of Greenwich, Schuylerville quadrangle
(U.S. G. S.), Washington County, N. Y.

Botsfordia ceelata. Hyolithellus micans (Billings).
Acrotreta sagittalis taconica. Microdiscus speciosus Ford.
Obolella sp. Olenellus thompsoni (Hall).

338i [U. S. National Museum]. Ordovician: Shales 1 mile (1.6 km.) west-northwest of South Argyle, near the line
between the Schuylerville and Cambridge quadrangles (U.S. G. S.), Washington County, N. Y.
Acrothele pretiosa.

338j [Hall, 1847, p. 4]. Upper Cambrian: Potsdam sandstone near Alexandria Landing, Jefferson County, N. Y.
Lingulella (Lingulepis) acuminata.

338k [U. S. National Museum]. (See 72a.) Lower Cambrian: Limestone 2.5 miles (4 km.) southwest of Wynants-
kill, Rensselaer County, N. Y. (L. M. Prindle, 1893).
Obolus prindlei.

3381 [U. S. National Museum]. (See 39a.) Lower Cambrian: Limestone in the northern part of daston, 3 miles
(4.8 km.) south of Greenwich, Cambridge quadrangle (U. 8. G. S.), Washington County, N. Y.
Lingulella granvillensis.

338m [U. S. National Museum]. Lower Cambrian: Limestone on the roadside north of schoolhouse No. 4, in the
northeast part of Whitehall, Whitehall quadrangle (U. 8. G. S.), Washington County, N. Y.
Lingulella granvillensis. .

338n [U. S. National Museum]. Lower Cambrian: Western belt of conglomeratic limestone, Rensselaer County,
ING WC
Yorkia washingtonensis. 5
Microdiscus lobatus (Hall).

3380[?]. Lower Cambrian: Shale on Moses Hill, 2 miles (3.2 km.) west of North Greenwich, near the line between
the Schuylerville and Cambridge quadrangles (U. S. G. S.), Washington County, N. Y.
Obolella crassa. :

338p [U. S. National Museum]. Lower Cambrian: Sandy limestone 0.25 mile (0.4 km.) northwest of schoolhouse
No. 7, in Greenwich, Cambridge quadrangle (U. S. G. S.), Washington County, N.Y.
Obolella chromatica.

338q [Hall, 1847, p. 290]. Lower Cambrian: Calcareous beds 2 miles (3.2 km.) northeast of Troy, Troy quad-
rangle (U. S. G. S.), Rensselaer County, N. Y.
*Obolella crassa.

338r [Billings, 1856, p. 34]. Upper Cambrian: Potsdam sandstone at Keeseville, Essex County, N. Y.
Lingulella (Lingulepis) acuminata.

338s [Emmons, 1842, pp. 267 and 268]. Upper Cambrian: Potsdam sandstone at High Bridge, on Ausable River,
Essex County, N. Y.
*Lingulella (Lingulepis) acuminata.
338t [U. S. National Museum records]. Upper Cambrian: Potsdam sandstone in Ausable Chasm, below Keese-
ville, Essex County, N. Y.
Lingulella prima.
Lingulella (Lingulepis) acuminata.
338u [U. S. National Museum records}. Ordovician and Upper Cambrian: In the strata from the upper layers of
the Potsdam sandstone to the lower portion of the ‘‘Calciferous sand rock” at Chateaugay Falls, Franklin

County, N. Y.
Lingulella (Lingulepis) acuminata (associated with Ophileta complanata in the upper beds).

338v [U. S. National Museum]. Ordovician: Shale 1 mile (1.6 km.) southwest of Middle Granville, Mettawee
quadrangle (U. S. G. S.), Washington County, N. Y.
*Obolus sp. undt. a.

LOCALITIES. 267

338w [Hall, 1847, p. 4]. Upper Cambrian: Potsdam sandstone at Hammond, St. Lawrence County, N. Y.
Lingulella (Lingulepis) acuminata.

338x [U. S. National Museum]. Lower Cambrian: Limestone 0.5 mile (0.8 km.) south of Coila, just east of Cam-:
bridge, Cambridge quadrangle (U. S. G. 8.), Washington County, N. Y. (C. D. Walcott, 1886).
Lingulella sp.
Acrotreta sagittalis taconica.

338y [U. S. National Museum]. Lower Cambrian: Limestone north of Eagle Mills, Rensselaer County, N. Y.
(T. N. Dale).
Acrotreta sagittalis taconica.

338z [U. S. National Museum]. Ordovician: Limestone on the north side of Bald Mountain, about 2 miles (3.2
km.) northwest of Greenwich, Schuylerville quadrangle (U. 8S. G. S.), Washington County, N. Y. (F. H.
Moffit, 1902).
Acrothele pretiosa.

339 [Sardeson, 1896, pp. 95 and 96]. Lower Ordovician: Oneota dolomite, Stillwater, Washington County, Minn.
*Obolus dolatus.
Orthis (Billingsella) pepina=Billingsella coloradoensis.

339a [Sardeson, 1896, p. 95]. Upper Cambrian: St. Lawrence formation at Otisville, Washington County, Minn.
‘Obolus (Westonia) aurora.

339b [U. S. National Museum]. Upper Cambrian: ‘St. Croix sandstone” at Arcola on St. Croix River, 7 miles
(11.2 km.) above Stillwater, Washington County, Minn.
Lingulella winona.

339c [U. S. National Museum]. Upper Cambrian: Reeds Landing, foot of Lake Pepin, Wabasha County, Minn.
Obolus (Westonia) aurora.

339d [U. S. National Museum]. (See 82b; may be same locality.) Upper Cambrian: “St. Croix sandstone” at
Taylors Falls, Chisago County, Minn.
Obolus matinalis. Eoorthis remnicha sulcata.
Lingulella similis. Syntrophia primordialis.

339e [U.S. National Museum]. Middle Cambrian: ‘“‘St. Croix sandstone” on Mountain Island, Minnesota, in
Mississippi River, just above the mouth of Trempealeau River. (See p. 159.)
*Lingulella ampla.
Dicellomus politus.

339f [U. S. National Museum]. Upper Cambrian: “St. Croix sandstone” near Minneiska (Miniska), on Mississippi
River, near the line between Wabasha and Winona counties, Minn. (F. M. Brown).
‘Obolus matinalis.
Billingsella coloradoensis.
Finkelnburgia finkelnburgi.

339g [U.S. National Museum]. Upper Cambrian: “‘St. Croix sandstone” just below the beds with Dikellocephalus
minnesotensis near Winona, Winona County, Minn.
Billingsella coloradoensis. Finkelnburgia osceola corrugata.
Finkelnburgia osceola. Syntrophia primordialis.

839h (references follow species). Upper Cambrian: “St. Croix sandstone”’ near the mouth of Minneiska (Miniska)

River, near the line between Wabasha snd Winona counties, Minn.
Obolus matinalis [ Hall, 1863, p. 130].
Lingulella (Lingulepis) acuminata [Hall, 1863, p. 130].
Orthis pepina | Hall, 1863, p. 135|=Billingsella coloradoensis.

839i [Owen, 1852, desc. of Pl. IB]. Middle Cambrian: Sandstones of Flb of Owen’s section, below Mountain
Isiand, in Mississippi River, nearly opposite the old mouth of Black River, southeastern Minnesota. (See
p- 159.)

*Diceliomus politus.
339j [U. S. National Museum]. Middle Cambrian: Sandstone between the lowest blue shale and the reddish
calcareous beds above, at Taylors Falls, Chisago County, Minn. (Chas. Schuchert). (See p. 159.)
Lingulella (Lingulepis) acuminata.
339k [U.S. National Museum]. Middle Cambrian: Sandstone near Winona, Winona County, Minn. (See p. 159.)
Lingulella (Lingulepis) acuminata.

340 [U.S. National Museum]. (See df.) Middle Cambrian: Limestone in Meagher County, on the road to Wolsey,
about 1 mile (1.6 km.) below the divide and 13 miles (21 km.) south of Neihart, Little Belt Mountains
quadrangle (U.S. G.8.), Cascade County, Mont. (W. H. Weed, F. B. Weeks, and C. D. Walcott, 1895).

Micromitra pealei. :

268 CAMBRIAN BRACHIOPODA.

340a [U. 8. National Museum]. (Same horizon as 4u.) Middle Cambrian: Shales near Helena, Jefferson County,
Mont. (L. S. Griswold).
Obolus (Westonia) ella.

340b [U. S. National Museum]. Upper Cambrian: Limestone at the mouth of Fourmile Creek, probably some-
where in the Threeforks quadrangle (U.S. G. S.), Gallatin County, Mont. (A. C. Peale).
Eoorthis desmopleura.

340c [U.S. National Museum]. Middle? Cambrian: Dark-red sandstone near the base of the Cambrian at Rawlins,
Carbon County, Wyo. (N. H. Darton).
Lingulella (Lingulepis) acuminata.

240d [U. S. National Museum]. Middle Cambrian: Limestone near the head of Bear River Canyon, Wyo. (A. C.
Peale).

Acrotreta attenuata.

340e [U. S. National Museum]. Middle? Cambrian: Shale on the west side of Cable Mountain, Phillipsburg
quadrangle (U.S. G. S.), Granite County, Mont. (F. C. Calkins, 1906).
Lingulella sp.

340f [U. S. National Museum]. Middle? Cambrian: Lowest beds exposed at the mouth of Bear Creek, Little Belt.
Mountains, Mont. (W. H. Weed, 1894).
Dicellomus politus.

341 [U. S. National Museum]. Upper Cambrian: Near Lansing, Allamakee County, Iowa.
*Lingulella winona (also cited from this locality by Hall, 1863, p. 126).
Finkelnburgia osceola.

341a[U.S. National Museum]. Upper Cambrian: Sandstone at McGregor, Clayton County, Iowa (F. W. Sardeson,.
1899).
Lingulella mosia.

342 [collection of J. Miquel]. Middle Cambrian: Shales in Montagne Noire, Coulouma, Department of Hérault,.
France.
*Acrothele bergeroni.

42a [collection of J. Miquel]. Passage beds between the Cambrian and the Ordovician, or Lower Ordovician:
Barren quartzitic beds, Coulouma, Department of Hérault, France.
*Yorkia? miqueli. :

343 [Rogers, 1875, p. 11, mentions specimens from Newport; U.S. National Museum has specimens labeled Narra-
gansett Bay]. Lower Ordovician: Limestone pebbles on the beach near Newport and at several points.
along the shores of Narragansett Bay, Rhode Island.

*Obolus (Westonia) rogersi.

243a [U. S. National Museum]. Upper Cambrian: Limestone pebbles on Checker Beach, near Newport, R. I.
(O. O. Nylander, 1893).
Lingulella sp. 1.
Lingulella sp. 2.

343b [U. S. National Museum]. Upper Cambrian: Limestone pebble on Sachuset Beach, near Newport, R. I..-
Lingulella bella.

344 (references follow species). (For stratigraphic position and association, see p. 133.) Middle Cambrian:
Sandy shales of Division E3b of Matthew’s [1903, p. 21] Etcheminian, on Dugald Brook, Indian River,
eastern Cape Breton, Nova Scotia.

Obolus lens [Matthew, 1903, p. 81]—Obolus (Palzeobolus)
bretonensis lens.
Lingulella atava [Matthew, 1903, p. 81].

Lingulella [Matthew, 1903, p. 58].
Acrothele abavia [Matthew, 1903, p. 81]—Acrothele avia.
Acrothele avia [Matthew, 1903, p. 81].

344a (references follow species). (For stratigraphic position and association, see p. 133.) Middle Cambrian:
Sandy shales of Division Ec of Matthew’s [1903, p. 21] Etcheminian, on Dugald Brook, Indian River,
eastern Cape Breton, Nova Scotia.
Lingulella sp. [Matthew, 1903, p. 26].
Lingulella collicia [Matthew, 1903, p. 26].
Acrothele abavia (Matthew, 1903, p. 26]—Acrothele avia.

Acrotreta sp. [Matthew, 1903, p. 26].
*Acrothyra proavia [Matthew, 1902b, p. 422].
Bradoria scrutator [Matthew, 1903, p. 163].

344b (references follow species). (For stratigraphic position and association, see p. 133.) (See 13n”). Middle
Cambrian: Sandy shales of Division E3d of Matthew’s [1903, p. 21] Etcheminian, on Dugald Brook, Indian.
River, eastern Cape Breton, Nova Scotia.
Lingulella atava [Matthew, 1903, p. 81].
*Obolus (Palzeobolus) bretonensis [Matthew, 1903, p. 81].
Acrothele ayia [Matthew, 19038, p. 81].

Acrothyra proavia (Matthew, 1903, p. 91].
*Bradorona spectator eequat [Matthew, 1903, p. 81].

LOCALITIES.

269

344c (references follow species). (For stratigraphic position and association, see p. 133.) Middle Cambrian: Sandy
shales of Division E3d of Matthew’s Etcheminian on Gregwa Brook, Indian River, eastern Cape Breton,

Nova Scotia.
Obolus (Palzeobolus) bretonensis [Matthew, 19038, p. 142].
*Acrothele avia puteis [Matthew, 1903, p. 100].

344d [Matthew, 1903, p. 82].

(See 13n.) (For stratigraphic position and association, see p. 133.) Middle Cam-

brian: Sandy shales of Division E3f of Matthew’s [1903, p. 21] Etcheminian, Dugald Brook, Indian River,

eastern Cape Breton, Nova Scotia.
Lingulella atava.
Leptobolus collicia=Lingulella collicia.
Leptobolus collicia collis=Lingulella collicia.
Acrothele proles.
Acrothyra proavia crassa=Acrothyra proavia.
Acrothyra proavia prima=Acrothyra proavia.
Hyolithes.
Leperditia? rugosa.

*Bradorona perspicator major.
Bradoria scrutator.

Escasona rutellum.

*Indiana lippa.

Eurypteroid crustacean.
Solenopleura bretonensis.
Schmidtella? acuta.

344e (references follow species). (For stratigraphic position and association, see p. 134,) Middle Cambrian: Shales
of Division Eld of Matthew’s [1903, pp. 28 and 29] Etcheminian on Boundary Brook, eastern side of the
Escasonie Indian Reservation, eastern Cape Breton, Nova Scotia. —

Lingulella cf. collicia [Matthew, 1903, p. 78].

Leptobolus atavus tritavus [Matthew, 1903, p. 78]=
Lingulella torrentis.

Lingulella (Lingulepis) gregwa [Matthew, 1903, p. 78].

Lingulella (Lingulepis) sp. [Matthew, 1903, p. 78].

Obolus sp. [Matthew, 1903, p. 78].

Acrotreta papillata [Matthew, 1903, p. 78]=Acrothyra
sera.

Acrotreta papillata lata [Matthew, 1908, p. 78]=Acro-
thyra sera.

Orthotheca sp. [Matthew, 1903, p. 78].

344f [Matthew, 1903, p. 72].

*Bradorona observator [Matthew, 1903, p. 78].

*Bradorona observator benepuncta [Matthew, 1903, p.
78].

Bradorona perspicator [Matthew, 1903, p. 78].

Bradorona spectator [Matthew, 1903, p. 78].

Bradorona spectator acuta [Matthew, 1903, p. 159].

Bradoria vigilans obesa [Matthew, 1903, pp. 78 and 152].

*Hscasona rutellum prima [Matthew, 1903, p. 78; rutel-
lum vetus on p. 152].

*Schmidtella (?) pervetus concinna [Matthew, 1903, p.
78).

(See 18k.) (For stratigraphic position and association, see p. 135.) Middle Cam-

brian: Shales of the Coldbrook terrane of Matthew, on Dugald Brook, Indian River, eastern Cape Breton,

Nova Scotia.
Obolus torrentis.
*Lingulella torrentis.
Lingulella cf. longovalis=Lingulella cf. triparilis.
*Lingulella (Lingulepis?) pumila.
Acrotreta papillata prima=Acrothyra sera.

344g (references follow species).

(For stratigraphic position and association, see p. 134.)

Acrothyra signata prima.
Hyolithes.

*Indiana ovalis prima.
*Hscasona?? ingens.

(See 13t”.) Middle

Cambrian: Shales of Division Ele of Matthew’s [1903, p. 21] Etcheminian, Dugald Brook, Indian River

Valley, Cape Breton, Nova Scotia.

Lingulella longovalis [Matthew, 1903, p. 77]=Lingulella
triparilis.

Lingulella triparilis [Matthew, 1903, p. 77].

Lingulella cf. tumida [Matthew, 1903, p. 23].

Lingulella (Lingulepis) gregwa [Matthew, 1903, p. 77].

Acrotreta papillata [Matthew, 1903, p. 95)]—Acrothyra
sera.

*Acrothyra signata sera [Matthew, 1903, p. 77]=Acro-
thyra sera.

Acrothyra signata tarda [Matthew, 1903, p. 77]=Acro-
thyra sera.

Hyolithes [Matthew, 1903, p. 77].

Orthotheca [Matthew, 1903, p. 77].

*Bradorona perspicator maxima [Matthew, 1903, p. 77].
Bradorona spectator [Matthew, 1903, p. 77].

*Bradoria ornata [Matthew, 1903, p. 77].

Bradoria rugulosa var. [Matthew, 1903, p. 166].
Bradoria vigilans obesa [Matthew, 1903, p. 152].
Crustacean [Matthew, 1903, p. 77]. —

344h (references follow species). (For stratigraphic position and association, see p. 134.) Middle Cambrian: Sandy
layers in the shales of Division Ele of Matthew’s [1903, p. 21] Etcheminian, Dugald Brook, Indian River,

eastern Cape Breton, Nova Scotia.

Obolus discus [Matthew, 1903, p. 79]=Lingulella tri-

parilis.

Lingulella longovalis [Matthew, 1903, p. 79]=Lingulella

triparilis.

Lingulella cf. tumida [Matthew, 1903, p. 24].

Lingulella (Lingulepis) gregwa robusta [Matthew, 1903,
p. 79].

Leptobolus sp. [Matthew, 1903, p. 79].

Obolus sp. [Matthew, 19038, p. 79].

Orthotheca sp. [Matthew, 1903, p. 79].

Hyolithes sp. [Matthew, 1903, p. 79].

*Bradorona spectator spinosa [Matthew, 1903, p. 79].
*Tndiana ovalis [Matthew, 1903, p. 79].

270 CAMBRIAN BRACHIOPODA.

344i (references follow species). (See 13 1.) ' (For stratigraphic position and association, see p. 133.) Middle
Cambrian: Sandy shales of Division E3a of Matthew’s [1903, p. 21] Etcheminian on Dugald Brook,
Indian River, eastern Cape Breton, Nova Scotia.

Acrothele abavia [Matthew, 1903, p. 80]=Acrothele avia.
Acrothyra proavia [Matthew, 1903, p. 80].
Obolus (Palzobolus) bretonensis [Matthew, 1903, p. 143].

Obolus lens [Matthew, 1903, p. 80]=Obolus (Palzeobolus)
bretonensis lens.

344j [Matthew, 1903, p.91]. (For stratigraphic position and association, see p. 133.) Middle Cambrian: Division
E8e of Matthew’s [1903, p. 21] Etcheminian on the highway at V. McPhees, eastern Cape Breton, Nova

Scotia.
Acrothyra proayvia.

344k (references follow species). (See13t’.) (Forstratigraphic position and association, see p.134.) Middle Cam-
brian: Sandstones of Division Elb of Matthew’s [1903, p. 21] Etcheminian on Dugald Brook, Indian

River, eastern Cape Breton, Nova Scotia.

Lingulella longovalis [Matthew, 1903, p. Hl Lingulella | *Acrothyra signata [Matthew, 1903, p. 77].

triparilis.
Lingulella triparilis [Matthew, 1903, p. 77].
Lingulella (Lingulepis) gregwa? [Matthew, 1903, p. 77].
Leptobolus? [Matthew, 1903, p. 77].

Bradorona observator levis [Matthew, 1908, p. 77].
Bradorona spectator [Matthew, 1903, p. 159].
*Bradorona spectator acuta [Matthew, 1903, p. 77].
*Bradoria vigilans obesa [Matthew, 1903, p. 77].

3441 (references follow species). (For stratigraphic position and association, see p. 134.) (See 13e.) Middle
Cambrian: Sandstones of Division E2c of Matthew’s [1903, p. 21] Etcheminian, Dugald Brook, Indian

River, eastern Cape Breton, Nova Scotia.
*Acrothyra signata orta [Matthew, 1903, p. 90].
Bradorona observator levis [Matthew, 1903, p. 161].

344m (references follow species). (See 13t/”.) (For stratigraphic position and association, see p. 134.) Middle
Cambrian: Sandy shales of Division Eld of Matthew’s eos, p. 21] Etcheminian on Dugald Brook,

Indian River, eastern Cape Breton, Nova Scotia.
*Linculella (Lingulepis) gregwa [Matthew, 1903, p. 78].
*Lingulella (Lingulepis) gregwa robusta [Matthew, 1903,

p. 78].
Acrotreta papillata [Matthew, 1903, p. 78]—Acrothyra
sera. }
Acrothyra signata tarda [Matthew, 1903, p. 78]—Acro-
thyra sera.

Orthotheca sp. [Matthew, 1903, p. 78].

Bradorona observator [Matthew, 1903, dese. of Pl. XII,
fig. 15].

Bradorona observator benepuncta [Matthew, 1903, desc.
of Pl. XII, fig. 16].

*Bradorona perspicator [Matthew, 1903, p. 157].

Bradorona spectator [Matthew, 1903, p. 78].

Bradorona spectator acuta [Matthew, 1903, p. 78].

344n [Matthew, 1903, p. 33]. (For stratigraphic position and association, see p. 134.) Middle Cambrian: Shales in
the gorge at the old mill on McCodrum Brook, Mira River, eastern Cape Breton, Nova Scotia.

Lingulella (Lingulepis) eregwa.

3440 [Matthew, 1903, p. 134]. (See10pand10q.) (For stratigraphic position and association, see p. 134.) Middle
Cambrian: Sandstones of Division E2b of Matthew’s [1903, p. 21] Etcheminian on Dugald Brook, Indian

River, eastern Cape Breton, Nova Scotia.
*Lingulella (Lingulepis) longinervis.

345 (references follow species). (For stratigraphic position and association, see p. 124.) Middle Cambrian: Green-
ish shale in the Paradoxides zone on the Dlouh4 Hora, above the brook of Sbiroyv, near Skrej, Bohemia.

Austria-Hungary.

*Lingulella (?) sp. [Pompeckj, 1896b, p. 509]—Lingulella | Ptychoparia striata [Pompeckj, 1896b, p. 509].

cf. ferruginea.
-Acrothele bohemica [Pompeckj, 1896b, p. 509].

Hllipsocephalus hoffi [Pompeckj, 1896b, p. 509].
Conocoryphe sulzeri [Pompeckj, 1896b, p. 511].

Billingsella romingeri [U. 8. National Museum and | Agraulos spinosus [Pompeckj, 1896b, p. 511).

Pompeckj, 1896b, p. 509].
*Orthis sp. [Pompeckj, 1896b, p. 514, fig. 6]—Hoorthis
sp. undt. a.

Agraulos ceticephalus [Pompeckj, 1896b, p. 511].

345a [Pompeckj, 1896b, p. 511]. (For stratigraphic position and association, see p. 124.) Middle Cambrian: Shales
in the Paradowides zone on the right bank of the brook of Karések, near Tejfovik, Bohemia, Austria-

Hungary.
Acrothele bohemica.

345b [Pompeckj, 1896b, p. 511]. (For stratigraphic position and association, see p. 124.) Middle Cambrian: In
the ‘‘Bande de Jinec”’ at Felbabka and Jinec, Bohemia, Austria-Hungary.

Acrothele bohemica.

LOCALITIES. 271

345c¢ (references follow species). (For stratigraphic position and association, see p. 124.) Middle Cambrian:
Shales of Etage C at Mleschitz, Bohemia, Austria-Hungary.
*Acrothele bohemica [Barrande, 1879b, Pl. CII].
Billingsella romingeri (U. S. National Museum).

845d [Pompeckj, 1896b, p. 511]. (For stratigraphic position and association, see p. 124.) Middle Cambrian:
Shales of Paradowides zone, Forester House of Slapy (Buchava quarry), Skrej, Bohemia, Austria-Hungary.
*Acrothele quadrilineata.

345e [Pompeckj, 1896b, p. 514]. (For stratigraphic position and association, see p. 124.) Middle Cambrian:
Greenish shale in the Paradowides zone in the gorge above Luh, near Skrej, Bohemia, Austria-Hungary.
*Hoorthis sp. undt. b.

345f (references follow species). (For stratigraphic position and association, see p. 124.) Middle Cambrian: Etage
C near Skrej, Bohemia, Austria-Hungary.
Nisusia (Jamesella) kuthani (U. S. National Museum).
*Billingsella romingeri [Barrande, 1879a, Pl. LXII].

345g [Barrande, 1879a, Pl. LXII]. (For stratigraphic position and association, see p. 124.) Middle Cambrian:
Etage C at Praschno Augezd, Bohemia, Austria-Hungary.
Billingsella romingeri.

345h [Barrande, 1879a, Pl. LXII]. (For stratigraphic position and association, see p. 124.) Middle Cambrian:
Etage C at Slap, Bohemia, Austria-Hungary.
Billingsella romingeri.

345i [U.S. National Museum and Pompeckj, 1896b, p. 514]. (For stratigraphic position and association, see
p- 124.) Lower Cambrian: Conglomeratic quartzitic sandstones and graywacke inclusions in the lower
conglomerate zone of the Kamenn4 htrka near Tejrovik, Bohemia, Austria-Hungary.
*Nisusia (Jamesella) kuthani. *Nisusia (Jamesella) perpasta macra.
*Nisusia (Jamesella) perpasta. *Nisusia (Jamesella) perpasta subquadrata.

345j [Pompeckj, 1896b, p. 514]. (For stratigraphic position and association, see p. 124.) Lower Cambrian: Con-
glomeratic quartzitic sandstones and graywacke inclusions in the lower comglomerate zone of the Kamenn4
hurka at Gross Lohovic, southwest of Skrej, Bohemia, Austria-Hungary.
Nisusia (Jamesella) kuthani. Nisusia (Jamesella) perpasta macra.
Nisusia (Jamesella) perpasta. Nisusia (Jamesella) perpasta subquadrata.

345k [U.S. National Museum]. (For stratigraphic position and association, see p. 124.) Lower Cambrian: Sand-
stones at Slapnicky mlyn, near Skrej, Bohemia, Austria-Hungary.
Nisusia (Jamesella) kuthani.
Nisusia (Jamesella) perpasta.

3451 [U.S. National Museum]. (For stratigraphic position and association, see p. 124.) Middle Cambrian: Shales
of Etage C at Jinec, Bohemia, Austria-Hungary (Museum Regni Bohemiz).
Billingsella romingeri.
346 [U.S. National Museum]. Lower Cambrian: Limestone and shale a little south of Emigsville, York County, Pa.
Acrothele decipiens.

346a [U. S. National Museum]. Lower Cambrian: Limestone in Landis Valley, Pa. (H. J. Roddy).
Micromitra (Paterina) bella.

346b [U.S. National Museum]. Upper Cambrian: Conococheague limestone,® 2.75 miles (4.4 km.) south of
Mercersburg, Franklin County, Pa.
Eoorthis desmopleura.

346¢ [U. S. National Museum]. Lower Cambrian: Shale near York, York County, Pa. (A. Wanner).
Nisusia festinata.

347 [von Toll, 1899, p. 27]. Lower Cambrian: Near Tschurskaja Station, on Lena River, Siberia.
Kutorgina cingulata.

850 [de Verneuil and Barrande, 1860, p. 538]. Middle Cambrian: Red limestone of the Paradowides zone near
Adrados, north of Sabero and Bofiar, Cantabrian Mountains, Province of Leon, northwestern Spain.

*Acrothele primeyva. Conocephalites sulzeri var.
*HKoorthis primordialis. Conocephalites coronatus.
“*Nisusia? vaticina. | Conocephalites ribeiro.
*Nisusia (Jamesella) pellico. Agnostus 2 sp.
*Brachiopode nouy. gen.=Botsfordia barrandei. Leperditia.
‘Paradoxides pradoanus. Capulus cantabricus.
Arionellus ceticephalus. Capulus sp.
Conocephalites sulzeri. Trochocystites bohemicus?.

a Stose, Mercersburg-Chambersburg folio (No. 170), Geol. Atlas U. S., U. S. Geol. Survey, 1909, p.6.

272 CAMBRIAN BRACHIOPODA.

350a [Barrois, 1882, p. 186]. Ordovician: Sandstones of the stage of Cabo Busto in the clifis of Cape Vidio, Province ©

of Oviedo, northeastern Spain.
*Lineulella heberti.

350b [Barrois, 1882, p. 186]. Ordovician: Sandstones of the stage of Cabo Busto at Los Negros, northeastern Spain.

Lingulella heberti.

351 (references follow species). ower Cambrian: Shalesat Monte de Valbom, northeast of Villa Boim, Province

of Alemtejo, Portugal.

Obolella maculata [Deleado, 1904, p. 364]—Acrothele
villaboimensis.

*Obolella cf. atlantica [Delgado, 1904, p. 364]=Obolella
sp.

*Acrothele villaboimensis [Deleado, 1904, p. 365].

*Deleadella lusitanica [Delgado, 1904, p. 365].

Lingulepis acuminata meeki [Delgado, 1904, p. 366]
=Lingulella delgadoi.

*Linoulella granvillensis [Delgado, 1904, p. 367]=Lingu-
lella delgadoi.

*Lineulella ferruginea [Delgado, 1904, p. 368]=Lingulella
delgadoi.

*Lingulella cf. linguloides [Delgado, 1904, p. 369]=Lin_
gulella delgadoi.

*Paradoxides choffati [Delgado, 1904, p. 319].

Paradoxides sp. aff, abenacus [Delgado, 1904, p. 322].

Paradoxides sp. n. aff. spinosus [Delgado, 1904, p. 323].

Paradoxides coste [Delgado, 1904, p. 323].

Paradoxides sp. aff. tessini [Delgado, 1904, p. 324].

Olenopsis sp.

Olenellus? (hypostoma).

Hicksia elvensis [Delgado, 1904, p. 333].

Hicksia spherica [Delgado, 1904, p. 335].

Hicksia transtaganensis [Delgado, 1904, p. 337].

Hicksia walcotti [Delgado, 1904, p. 338].

Hicksia castroi [Delgado, 1904, p. 340].

Hicksia hughesi [Delgado, 1904, p. 341].

Hicksia barroisi [Delgado, 1904, p. 342].

Hicksia delwalquei [Delgado, 1904, p. 343].
Hicksia minuta [Delgado, 1904, p. 344].
Metadoxides bornemanni [Delgado, 1904, p. 345].
Olenellus (?) macphersoni [Delgado, 1904, p. 347].
Microdiscus caudatus [Delgado, 1904, p. 349].
Microdiscus subeaudatus [Delgado, 1904, p. 350].
Microdiscus wenceslasi [Delgado, 1904, p. 350].
Microdiscus souzai [Delgado, 1904, p. 351].
Microdiscus woodwardi [Delgado, 1904, p. 353].
Crustacean (?) (telson).

Crustacean sp.

Hyolithes lusitanicus [Delgado, 1904, p. 355].
Hyolithes cf. billingsi [Delgado, 1904, p. 356].
Hyolithes sp. aff. communis [Delgado, 1904, p. 356].
Pteropoda sp.

Posidonomya malladai [Delgado, 1904, p. 357].
Fordilla troyensis [Delgado, 1904, p. 358].
Modiolopsis zitteli [Delgado, 1904, p. 359].
Modiolopsis bocagei [Delgado, 1904, p. 360].
Synek (?) cambrensis [Delgado, 1904, p. 360].
Davidia dolliusi [Delgado, 1904, p. 361].
Davidia cotteri [Delgado, 1904, p. 362].

Davidia egozcuei [Delgado, 1904, p. 362]. ,
Ctenodonta geikiei [Delgado, 1904, p. 363].
Bivalve sp.

These species may not be from the same bed or even from the same locality.

353 [Roemer, 1849, p. 420]. Upper Cambrian: Limestones on San Saba River, San Saba County, Tex.
*Lingulella acutangula. No other associated species (Roemer).

353a [Shumard, 1860, p. 627]. Upper Cambrian: Sandstones near the head of Morgans Creek, Burnet County, Tex.

~*Billingsella coloradoensis.

353b [U. S. National Museum]. Upper Cambrian: Sandstone just beneath the Ophileta beds, south end of the

Franklin Range, El Paso County, Tex.
Lingulella (Lingulepis) acuminata.

358c [U. S. National Museum]. Upper Cambrian: Heavy dark ferruginous sandstone in Llano County, Tex.

(exact locality unknown).
Lingulella acutangula.

354 (references follow species). Middle? Cambrian: In yellowish-brown slates not far from the buildings of Canal

Grande, island of Sardinia, Italy.

*Lingula attenuata [Bornemann, 1891, p. 438]=Lingulella | Olenopsis [Bornemann, 1891, p. 440].

bornemanni.

Metadoxides [Bornemann, 1891, p. 440].

*Kutorgina cingulata [Bornemann, 1891, p. 440]=Kutor- | Lingulella sp. undt. (U. S. National Museum),

gina sardiniaensis.

These species may not be from the same bed or even from the same exact locality.

354a (references follow species). Middle? Cambrian:

Gutturu Sartu, island of Sardinia, Italy.

In grayish-white quartzitic sandstone in the valley of

*Lingula hawkei [Bornemann, 1891, p. 439]=Mickwitzia | Olenopsis zoppi [Bornemann, 1891, p. 459].

sp. undt.

Metadoxides armatus [Bornemann, 1891, p. 465]. -

Lingula attenuata [Bornemann, 1891, p. 438]=Lingulella | Metadoxides bornemanni [Bornemann, 1891, p. 466].

bornemanni.
‘Olenopsis bornemanni [Bornemann, 1891, p. 458].

Metadoxides torosus [Bornemann, 1891, p. 462].
Ete.

These species may not be from the same bed or even from the same exact locality.

LOCALITIES. 273

854b (references follow species). (See 354c.) Middle? Cambrian: In yellowish sandstone with Archzxocyathus
at Punta Pintau and elsewhere, island of Sardinia, Italy.
Lingula attenuata [Bornemann, 1891, p. 438]—Lingulella | Carinaropsis patelloides [Bornemann, 1891, p. 441].

bornemanni. Capulus minutus [Bornemann, 1891, p. 441].
Kutorgina cingulata [Bornemann, 1891, p. 440]=Kutor- | Olenopsis bornemanni [Bornemann, 1891, p. 458].
gina sardiniaensis. Ete.

These species may not be from the same bed or even from the same exact locality.

854e (references follow species). (See 354b.) Middle? Cambrian: Yellow friable sandstone at Punta Pintau
(Canal Grande), island of Sardinia, Italy.
*Lingula petalon [Bornemann, 1891, p. 438]=Obolus? | Paradoxides asper [Bornemann, 1891, p. 468].
meneghinii. Htc.
Metadoxides arenarius [Bornemann, 1891, p. 467].
These species may not be from the same bed or even from the same exact locality.

354d [Bornemann, 1891, p. 438]. Middle ? Cambrian: Yellow friable sandstone at Gruguetta, island of Sardinia,
Italy.
Lingula petalon=Obolus? meneghinii. '
354e (references follow species). Middle ? Cambrian: Shale at Porto Canal Grande, island of Sardinia, Italy.
Obolella sp. [Bornemann, 1891, p. 440]=Obolus? mene- | Olenopsis bornemanni [Bornemann, 1891, p. 458].

ghinil. Olenopsis longispinatus [Bornemann, 1891, p. 459].
Lingula roualti [Bornemann, 1891, p. 439]=Kutorgina sar- | Olenopsis zoppi [Bornemann, 1891, p. 459].

diniaensis. Metadoxides armatus [Bornemann, 1891, p. 465].
Kutorgma sardiniaensis (U. S. National Museum). Kte.

Bellerophon? priscus [Bornemann, 1891, p. 441].
These species may not be from the same bed or even from the same exact locality.

354f [Bornemann, 1891, p. 439; U. S. National Museum]. Middle ? Cambrian: Reddish-yellow sandstone near the
houses of Canal Grande,, on the road to Punta Pintau, island of Sardinia, Italy.
*Obolella crassa=Obolus? zoppi.

355 [U. S. National Museum]. Middle Cambrian: Sandstones on Red Canyon Creek, southwest side of Black
Hills, South Dakota. Some of the specimens are labeled Redwater Canyon, and this locality appears in
Whitfield [1882, p. 340].
*Lingulella cuneola. Dicellomus nanus.
*Lingulella perattenuata. : Dicellomus politus.
Lingulella (Lingulepis) acuminata.

355a [U. S. National Museum]. Middle Cambrian: Shales in Bear Gulch Valley, Black Hills, South Dakota.
Lingulella similis.

355b [U. S. National Museum]. Middle Cambrian: Sandstone in the Deadwood formation on Castle Creek, on the
west side of the Black Hills, South Dakota.
Lingulella (Lingulepis) acuminata.
Dicellomus pectenoides.
855¢ [Whitfield, 1875, p. 103]. Middle Cambrian: Sandstone on French Creek, Black Hills, South Dakota.
*Dicellomus pectenoides.

355d [U. S. National Museum]. Middle Cambrian: Sandstone in the Black Hills, South Dakota.
Lingulella (Lingulepis) acuminata.
*Dicellomus nanus.

355e[U.S. National Museum]. Middle Cambrian: Sandstone in the central part of the Black Hills, South Dakota.
Dicellomus politus.

355f.2 Middle Cambrian: Sandstones near Deadwood, Black Hills, South Dakota.
Lingulella perattenuata.

357 [Waagen, 1885, p. 769]. Middle Cambrian: Limestone in the ‘‘Neobolus beds’’ of the Khussak group, above
the salt mine at Kiura (Khewra), Salt Range, India.
*Lingulella kiurensis.
357a (references follow species). Middle Cambrian: Lower portion of the ‘‘ Neobolus beds” of the Khussak group,
in purplish-colored, fine-grained, micaceous sandstone, at Juténa, Salt Range, India.
*Neobolus warthi [Waagen, 1885, p. 759].-..-----
Neobolus wynnei [Waagen, 1885, p. 760] ..---.--
Davidsonella linguloides [Waagen, 1885, p. 765]- -
Davidsonella squama [Waagen, 1885, p. 767]-----
*Discinolepis granulata [Waagen, 1885, p. 751].

=Neobolus warthi.

a The authority for the citation of this locality was mislaid and could not be traced in time for insertion in this volume.

62667°—vot 51, gr 1—12——_18

274 CAMBRIAN BRACHIOPODA.

357b [Waagen, 1885, p. 759]. Middle Cambrian: Lower portion of the ‘‘Neobolus beds” of the Khussak group,
in purplish-colored, fine-grained, micaceous sandstone, at Chél Hill, Salt Range, India.
Neobolus warthi.

357¢ (references follow species). Middle Cambrian: Lower portion of the “‘ Neobolus beds” of the Khussak group,

in purplish-colored, fine-grained, micaceous sandstone, near the fresh-water springs in a gorge above the
salt mines at Kiura (Khewra), Salt Range, India.

*Schizopholis rugosa [Waagen, 1885, p. 754].

Neobolus warthi [Waagen, 1885, p. 759].-...-----

Neobolus wynnei [Waagen, 1885, p. 760].---.--.- | venom warthi.

Davidsonella linguloides [Waagen, 1885, p. 765]. .

Discinolepis granulata [Waagen, 1885, p. 751].

357d [Waagen, 1891, p. 104]. Middle Cambrian: “‘Concretionary shales of the Khussak group’’ at several locali-
ties between Chél Hill and Kiura (Khewra), eastern part of the Salt Range, India.
*Wynnia warthi. Conocephalites warthi.
Hyolithes wynnei. Trilobites gen. and sp. undt.

358 (U.S. National Museum]. Middle Cambrian: Argillaceous shale 50 feet (15.2 m.) above the Coronado quartzite
[Lindgren, 1905, p. 3], west side of Chase Creek Canyon, 1.5 miles (2.4 km.) east-northeast of Morenci, Clif-
ton quadrangle (U. 8. G. S.), Graham County, Ariz.

Lingulella lineolata.

358a [U. 8. National Museum]. Upper? Cambrian: Siliceous limestone on Ash Creek, in Pinal County, Ariz.
Lingulella pogonipensis?.
Dicellomus politus.

358b [U. S. National Museum]. Middle Cambrian: Limestone on the southwest side of Escabrosa Ridge, 4.5 miles
(7.2 km.) west-southwest of Bisbee, Ariz. (F. L. Ransome, 1902).
Obolus zetus.

360 [U. S. National Museum]. Lower Ordovician: Red siliceous limestone near Colorado Springs, El] Paso County,
Colo.
Lingulella desiderata.
Schizambon manitouensis.
Eoorthis desmopleura.

360a [U. S. National Museum]. Lower Ordovician: Red siliceous limestone on west side of Trout Creek, below
Bergen Park, 7 miles (11.2 km.) north-northwest of Manitou, El Paso County, Colo.
Obolus matinalis. Eoorthis desmopleura.
Lingulella desiderata. Eoorthis wichitaensis.

360b [U. S. National Museum]. Lower Ordovician: Red siliceous limestone on Cement Creek, 3 miles (4.8 km.)
north of Hot Springs, Ouray County, Colo.
Lingulella desiderata.

360c [U. S. National Museum]. Lower Ordovician: Red siliceous limestone about 10 miles (16.1 km.) southeast
of Crested Butte, Elk Range, Colo.
Lingulella desiderata.

360d [U.S. National Museum]. Middle Cambrian: Siliceous limestones near Pike View, north of Colorado Springs,
El Paso County, Colo.
Lingulella similis.

360f [U. S. National Museum]. Lower Ordovician: Siliceous limestone at Glen Eyre, Queens Canyon, northeast
of Manitou, El Paso County, Colo.
*Koorthis desmopleura.

360g [U. S. National Museum records]. Upper Cambrian: Shaly sandstone on Trout Creek, 1 mile (1.6 km.) below
Manitou Park, El Paso County, Colo.
Lingulella (Lingulepis) acuminata.

360h [U.S. National Museum]. (100 feet above 3601; see locality 3g.) Upper Cambrian: Sandy shales about 200
feet (61 m.) above the base of the section at Glenwood Springs, Garfield County, Colo. (T. W. Stanton, 1889).
Obolus mezera.

860i [U. S. National Museum]. (100 feet below 360h; see locality 3g.) Upper Cambrian: Sandstones about 100
feet (30 m.) above the base of the section at Glenwood Springs, Garfield County, Colo. (T. W. Stanton, 1889).
Obolus meera.

LOCALITIES. 215

361 [U. S. National Museum]. (For stratigraphic position and association, see p. 147.) Upper Cambrian: Shaly
limestone in suburb of Attalla, Etowah County, Ala. (M. R. Campbell).
Lingulella desiderata.
Acrotreta kutorgai.

362 [U. S. National Museum]. (For stratigraphic position and association, see p. 147.) Upper Cambrian: Shales
in the Oothkalooga Valley, Bartow County, Ga.
Linegulella desiderata.

362a [U. S. National Museum]. (For stratigraphic position and association, see p. 147.) Middle Cambrian: Sandy
shale a short distance west of Cave Spring, Floyd County, Ga.
Lingulella similis.

364 [Sardeson, 1896, p. 95]. Upper Cambrian: St. Lawrence formation in both Wisconsin and Minnesota.
Lingulella mosia.

364a [Sardeson, 1896, p. 95]. Lower Ordovician: “‘Oneota dolomite” along St. Croix River in both Wisconsin
and Minnesota.
Lingulella mosia.

366 [Davidson, 1866, p. 57]. (For stratigraphic position and association, see p. 135.) Upper Cambrian: Whitesand
Bay, near St. Davids Head, Pembrokeshire, South Wales.
Lingulella davisi.

366a [U.S. National Museum]. (For stratigraphic position and association, see p. 135.) Upper Cambrian: Upper
portion of Middle Lingula flags 6 miles (9.6 km.) east of Ffestiniog, Merionethshire, North Wales.
Lingulella davisi.

866b [U. S. National Museum]. (For stratigraphic position and association, see p. 136.) Middle Cambrian: Red
shales at the base of the Harlech grits at Porthclais Harbor, south of St. Davids, South Wales.
Lingulella ferruginea.

366c [Salter and Etheridge, 1881, p. 538]. (See 318i.) (For stratigraphic position and association, see p. 186.)
Middle? Cambrian: ‘“‘Caerfai group” at Caerfai, Nuns Hill, and Porthclais Harbor, south of St. Davids,
South Wales.
*Lingulella primeva.

366d [Davidson, 1866, p. 57]. (For stratigraphic position and association, see p. 135.) Upper Cambrian: Lower
Lingula flags at Carnedd Filiast, Bangor, Carnarvonshire, North Wales.
Lingulella davisi.

366e [Davidson, 1866, p. 57]. (For stratigraphic position and association, see p. 135.) Upper Cambrian: Lower
Lingula flags at Marchillyn-mawr, Llanberis, Carnarvonshire, North Wales.
Lingulella davisi.

366f [Davidson, 1866, p. 57]. (For stratigraphic position and association, see p. 135.) Upper Cambrian: Lower
Lingula flags at Ffestiniog, Merionethshire, North Wales.
Lingulella davisi.

366g [Davidson, 1866, p. 57]. (For stratigraphic position and association, see p. 135.) Upper Cambrian: Lower
Lingula flags at Dolgelly, Merionethshire, North Wales.
Lingulella davisi.

366h [Davidson, 1866, p. 57]. (For stratigraphic position and association, see p. 135.) Upper Cambrian: Lower
Lingula flags at Pen-y-Bryn, 5 miles (8 km.) north of Dolgelly, Merionethshire, North Wales.
Lingulella davyisi. }

366i [Davidson, 1866, p. 57]. (For stratigraphic position and association, see p. 135.) Upper Cambrian: Lower
Lingula flags at Llyn Dywarchen, Merionethshire, North Wales.
Lingulella davisi.

366j [Davidson, 1866, p. 57.] (For stratigraphic position and association, see p. 135.) Upper Cambrian: Lower
Lingula flags at Pont Nant-y-Lladron, on the Bala Road from Ffestiniog, Merionethshire, North Wales.
Lingulella davisi.

366k [Davidson, 1866, p. 57]. (For stratigraphic position and association, see p. 135.) Upper Cambrian: Lower
Lingula flags at Penmorfa, Merionethshire, North Wales.
Lingulella davisi.

3661 [Davidson, 1866, p. 57). (For stratigraphic position and association, see p. 135). Upper Cambrian: Lower
Lringula flags at Tremadoc, Merionethshire, North Wales.
Lingulella davisi.

276 CAMBRIAN BRACHIOPODA.

366m [Davidson, 1866, p. 57], (For stratigraphic position and association, see p. 135.) Upper Camprian: Lower
Lingula flags near Nant-y-groes, west of Bala, Merionethshire, North Wales,
Lingulella davisi.

366n [U.S. National Museum]. (For stratigraphic position, and association, see p. 135.) Upper Cambrian: Lower
Lingula flags at Portmadoc, Merionethshire, North Wales.
Lingulella davyisi.

3660 [McCoy, 1854, p. 254]. (For stratigraphic position and association, see p. 135.) Upper Cambrian: ‘‘Bala
schists” at Bryn Melyn, near Bala, Merionethshire, North Wales.
Lingulella davisi.

366p [Davidson, 1866, p. 57]. (For stratigraphic position and association, see p. 135.) Upper Cambrian: Upper
Tremadoc beds at Deudraeth, Merionethshire, North Wales.
Lingulella davisi.

.
366q (references follow species). (Jor stratigraphic position and association, see p. 135.) Upper Cambrian: Upper
Tremadoe beds at Garth, opposite Portmadoc, Merionethshire, North Wales.
Lingulella dayisi [Davidson, 1866, p. 57].
Lingulella lepis [Davidson, 1866, p. 54].

366r [U.S. National Museum]. (For stratigraphic position and association, see p. 135.) Upper Cambrian: Shales
2 miles (3.2 km.) north of Builth, Brecknockshire, South Wales.
Lingulella davisi.

366s [U. S. National Museum]. (See 366a.) (lor stratigraphic position and association, see p. 135.) Upper
Cambrian: Upper Lingula flags 5 miles (8 km.) east of Ffestiniog, Merionethshire, North Wales.
Orusia lenticularis.

367 [U. S. National Museum]. Lower Cambrian: Conglomerate and limestone, Troy, Rensselaer County, N. Y-.
*Lingulella schucherti.
Microdiscus schucherti.
Protypus hitcheocki (Whitfield).
These species may be from widely different localities.

367a [U. S. National Museum]. (See 38.) Lower Cambrian: Limestone about a third of a mile (0.5 km.) south
of John Hulett’s farmhouse, 3 miles (4.8 km.) west of South Granville, and 4.5 miles (7.2 km.) southwest
of Granville, Fort Ann quadrangle (U.S. G. 8.), Washington County, N. Y.
Billingsella salemensis.

367b [U. S. National Museum]. Lower Cambrian: Sandstone at Lansingburg, north of Troy, Cohoes quadrangle
(U. 8. G. S.), Rensselaer County, N. Y.
Billingsella salemensis??. :
Scenella sp.

367e [U. S. National Museum]. Ordovician: Beekmantown limestone, Division A, quarry near the northwest
suburbs of Ticonderoga, Essex County, N. Y.
*Lingulella (Lingulepis) acuminata sequens.

367d (references follow species). Middle Cambrian: Limestones near Stissing, Dutchess County, N. Y.
*Micromitra (Paterina) stissingensis [Dwight, 1889, p. 145]. | *Leperditia ebenina [Dwight, 1889, p. 144].
Hyolithes billingsi? [Dwight, 1889, p. 143]. *Olenoides stissingensis [Dwight, 1889, p. 147].

367e [Dwight, 1886, p. 205]. Upper Cambrian: Shaly limestones 850 feet (259.1 m.) southerly from the southwest
corner of the driving park and 2,200 feet (670.6 m.) west of the road leading southerly from the same, about
1 mile (1.6 km.) southwest of Vassar College, near Poughkeepsie, Dutchess County, N. Y.
Lingulella (Lingulepis) acuminata.

367£[U. S. National Museum]. Upper Cambrian: Sandstone at French Creek, 1 mile (1.6 km.) east of Keesevilte,
Essex County, N. Y. :
Lingulella prima.

367g [U.S. National Museum]. Upper Cambrian: Sandstone in the bed of the brook in the suburbs of Port Henry,
Essex County, N. Y.
Lingulella prima.

367h [U. S. National Museum]. Upper Cambrian: Sandstone at Rosses Bridge, 4 miles (6.4 km.) west of Essex
village, Essex County, N. Y.
Lingulella prima.

LOCALITIES. 217

367i [Hall, 1847, p. 290]. Lower Cambrian: Shales near Troy, Rensselaer County, N. Y.
*Botsfordia ceelata.

367j [U. S. National Museum]. (See 108.) Upper Cambrian: Sandstones 3 miles (4.8 km.) south of Pough-
keepsie, Dutchess County, N. Y.
Lingulella (Lingulepis) acuminata.

367k [U. S. National Museum]. (See 109.) Upper Cambrian: Sandstone at Deweys Bridge, Washington County,
N. Y.
Lingulella (Lingulepis) acuminata.

3671 [U. S. National Museum]. Cambrian: Shales 0.75 mile (1.2 km.) southwest of Hillsdale, Fort Ann quad-

rangle (U.S. G. S.), Washington County, N. Y. (L. M. Prindle, 1895).
Obolus sp.

368 (references follow species). Middle Cambrian: Quartzitic sandstone in the Pepper Mountains, near Sandomierz
on the Vistula, Russian Poland.

Obolus apollinis (U.S. National Museum). Paradoxides bohemicus [Gurich, 1896, p. 17].

*Lingulella siemiradzkii (U.S. National Museum). Agnostus fallax [Gurich, 1896, p. 17].

Lingula cf. crassa [Gurich, 1896, p. 214]—Lingulella | Agnostus gibbus [Gurich, 1896, p. 17].
siemiradzkii. Liostracus linnarssoni [Gurich, 1896, p. 17].

Paradoxides cf. tessini [Gurich, 1896, p. 17].

868a [Siemiradzki, 1886, p. 672]. Gray sandstone of unknown stratigraphic position or age in the Polnischen
Mitteleebirge, north of Sandomierz on the Vistula, Russian Poland.
Obolus (Mickwitzella) siluricus.

869 [U. S. National Museum]. (For stratigraphic position and association, see p. 137.) Upper Cambrian: Sand-
stone in the Elvins formation in the eastern limits of the town of Flat River, St. Francois County, Mo.
*Obolus ismene. Linnarssonella girtyi.
Lingulella texana. EKoorthis indianola.

369a [U.S. National Museum]. (For stratigraphic position and association, see p. 187.) Middle Cambrian: Lime-
stone in or just beneath the ‘‘ Edgewise beds” near Elvins, 6 miles (9.6 km.) south of Bonneterre, St. Francois
County, Mo.
Eoorthis wichitaensis.

369b [U. S. National Museum]. Upper Cambrian: Limestone near Potosi, Washington County, Mo.
Eoorthis indianola.

369c [U.S. National Museum]. (For stratigraphic position and association, see p. 137.) Upper Cambrian: Dolomite
above the ‘‘Edgewise beds” in a railroad cut 0.5 mile (0.8 km.) southwest of Elvins, 6 miles (9.6 km.) south
of Bonneterre, St. Francois County, Mo. (E. O. Ulrich).
Billingsella major?.

369d [U.S. National Museum]. (For stratigraphic position and association, see p. 137.) Upper Cambrian: Upper
portion of the Elvins formation 2.5 to 3 miles (4 to 4.8 km.) north of Caledonia, Washington County, Mo.
Billingsella coloradoensis.

369e [U.S. National Museum]. (or stratigraphic position and association, see p. 1387.) Upper Cambrian: Sand-
stone on Big River, near Montana, Iron County, Mo.
Billingsella coloradoensis.

369 [Walcott, 1891b, p. 341]. (For stratigraphic position and association, see p. 137.) Middle Cambrian: Lime-
stone at Fredericktown, Madison County, Mo. ‘
Obolus lamborni.

369g [U. S. National Museum]. (For stratigraphic position and association, see p. 137.) Middle Cambrian: Shales
at Bonneterre, St. Francois County, Mo.
Lingulella desiderata. -

369h [U.S. National Museum]. (For stratigraphic position and association, see p. 137.) Middle Cambrian: Shale
at Mine Lamotte, Madison County, Mo. (C. D. Walcott and F. B. Meek).
Obolus lamborni.
372 [U.S. National Museum]. (See 8d.) (Forstratigraphic position and association, see p. 131.) Upper Cambrian:
Shale at Upper Leitches Creek, eastern Cape Breton, Nova Scotia.
Lingulella concinna.

372a [U.S. National Museum]. (See 10m.) (For stratigraphic position and association, see p. 131.) Upper Cam-
brian: Shale 2 miles (3.2 km.) south of the Boisdale road from Upper Leitches Creek, eastern Cape Breton,
Nova Scotia.
Lingulella concinna.

278 CAMBRIAN BRACHIOPODA.

372b [U. S. National Museum]. (See 3p.) (For stratigraphic position and association, see p. 131.) Upper Cam-
brian: Shale in ravine 0.5 mile (0.8 km.) north of McMullins, on the crossroad to Boisdale railroad station,
eastern Cape Breton, Nova Scotia.
Lingulella concinna.

372c [U. S. National Museum]. (See30.) (For stratigraphic position and association, see p. 131.) Upper Cambrian:
Shale in ravine east of the railroad, just south of Barachois post office, eastern Cape Breton, Nova Scotia.
Lingulella concinna.

372d [U. S. National Museum]. (For stratigraphic position and association, see p. 131.) Upper Cambrian: Shale
on McAdam shore, East Bay, east of Bras d’Or Lake, eastern Cape Breton, Nova Scotia.
Lingulella concinna.

372e [Matthew, 1903, p. 50]. (For stratigraphic position and association, see p. 131.) Upper Cambrian: Shales
on McMullins Brook, near McLeod Brook (=Barachois River), eastern Cape Breton, Nova Scotia, Canada.
Monobolina refulgens.
Schizambon priscus.

372f [U.S. National Museum]. (For stratigraphic position and association, see p. 134.) Middle Cambrian: Shales
on Dugald Brook, Indian River, eastern Cape Breton, Nova Scotia. j
Lingulella (Lingulepis) longinervis.

374 [U.S. National Museum]. (For stratigraphic position and association, see p. 147.) Middle Cambrian: In the
suburbs of and 4 and 11 miles (6.4 and 17.7 km.) north-northeast of Knoxville, Knox County, Tenn.
Lingulella similis.

374a [U.S. National Museum]. (Forstratigraphic position and association, see p. 147.) Middle Cambrian: Lime-
stone 2 miles (3.2 km.) south of Coal Creek, Anderson County, Tenn.
Dicellomus appalachia.

374b [U.S. National Museum]. (Forstratigraphic position and association, see p. 147.) Middle Cambrian: Shale
1.25 miles (2 km.) from Rogersville, on the road to Powell, near the line between the Morristown and Greene-
ville quadrangles (U. S. G. S.), Hawkins County, Tenn.
Dicellomus appalachia.

374c [U. S. National Museum]. (For stratigraphic position and association, see p. 147.) Middle Cambrian: Sandy
shale (Nolichucky?) [Campbell, 1899, p. 3] 8 miles (12.8 km.) northeast of Shipleys, near the line between
the Roan Mountain and Bristol quadrangles (U. 8. G. S.), Sullivan County, Tenn.
Dicellomus appalachia.

374d [U.S. National Museum]. (For stratigraphic position and association, see p. 147.) Middle Cambrian: Shale
2 miles (3.2 km.) north of Rotherwood, Hawkins County, Tenn. (Cooper Curtice).
Lingulella (Lingulepis) acuminata.

374e [U.S. National Museum]. (For stratigraphic position and association, see p. 147.) Middle Cambrian: Shales
collected near the state line, 2.25 miles (3.6 km.) north of Peltier, Estillville quadrangle (U. 8. G. S.), Sulli-
van County, Tenn. (M. R. Campbell).
Obolus willisi.

386 [Gagel, 1890, p. 34]. Passage beds between the Upper Cambrian and the Ordovician: Drift blocks of Cerato-
pyge limestone near Belschwitz, East Prussia, Germany.
Eoorthis daunus.

386a [Gagel, 1890, p. 34]. Passage beds between the Upper Cambrian and the Ordovician: Drift blocks of ‘‘Glau-

conite limestone’’ near Prussian Holland, 90 miles (145 km.) south-southwest of Konigsberg, East Prussia,
Germany.
Orthis christianize=Hoorthis daunus?.

386b (references follow species). Passage beds between the Upper Cambrian and Ordovician: Drift blocks of
““Glauconite limestone” near Wehlau, 30 miles (48.3 km.) east of Konigsberg, East Prussia, Germany.
Obolus (Acritis) antiquissimus [Gagel, 1890, p. 22]. | ; tee ’
Orthis christianiz [Gagel, 1890, p. 34]—=Eoorthis daunus?.{ /bese species may occur in different blocks of limestone.

386c [Roemer, 1885, p. 23 (270)]. Upper Cambrian: Drift bowlder found near Lyck, East Prussia, Germany.
Obolus apollinis.

386d [Roemer, 1885, p. 23 (270)]. Upper Cambrian: Drift bowlder found near Danzig, West Prussia, Germany.
Obolus apollinis.

886e [Roemer, 1885, p. 33 (280)]. Upper Cambrian: Drift bowlders of gray bituminous limestone between
Vistula and Hlhe rivers. in Schleswig-Holstein and Mecklenburg-Schwerin, Germany.
Orusia lenticularis.
Parabolina spinulosa.

LOCALITIES. 979

886i [Roemer, 1885, p. 34 (281)]. Upper Cambrian: Drift bowlders of gray bituminous limestone near Wismar,
Mecklenburg-Schwerin, Germany.
Orusia lenticularis.

386g [Roemer, 1885, p. 34 (281)]. Upper Cambrian: Drift bowlders of gray bituminous limestone near Rostock,
Mecklenburg-Schwerin, Germany.
Orusia lenticularis.

386h [Roemer, 1885, p. 34 (281)]. Upper Cambrian: Drift bowlders of gray bituminous limestone near Meseritz,
Province of Posen, Germany.
Orusia lenticularis.

386i (referencesfollow species). (For stratigraphic position and association, see p. 143.) Ordovician: Drift bowlder
of Echinosphzrites limestone near Wehlau, 30 miles (48.3 km.) east of Konigsberg, Hast Prussia, Germany.
Siphonotreta unguiculata [Gagel, 1890, p. 23].
Siphonotreta verrucosa [Gagel, 1890, p. 22].
386j [Gagel, 1890, p. 23]. (For stratigraphic position and association, see p. 143.) Ordovician: Drift bowlder of
Echinosphexrites limestone at Belschwitz, East Prussia, Germany.
Siphonotreta unguiculata.
386k [Gagel, 1890, p. 22]. (For stratigraphic position and association, see p. 143.) Ordovician: Drift bowlder of
Echinosphexrites limestone near Wormditt, East Prussia, Germany.
Siphonotreta unguiculata.
Siphonotreta verrucosa.
3861 [Gagel, 1890, p. 22]. (For stratigraphic position and association, see p. 143.) Ordovician: Drift bowlder of
Echinospherites limestone near Marienwerder, West Prussia, Germany.
Siphonotreta unguiculata.
Siphonotreta verrucosa.
389 [Kayser, 1876, p. 8]. Upper Cambrian: Sandstone at Salta, Province of Salta, Argentina, South America.
*Hoorthis saltensis.
“89a [Kayser, 1876, p. 8]. Upper Cambrian: Sandstone at Nevado de Castillo, Province of Salta, Argentina,
South America.
Hoorthis saltensis.
389b (references follow species). Upper Cambrian: Sandstone at Tilcuya, Province of Jujuy, Argentina, South

America.
Orusia lenticularis [Kayser, 1876, p. 9]. Agnostus tilcuyensis [Kayser, 1876, p. 5].
Eoorthis saltensis [Kayser, 1876, p. 8]. Olenus argentinus [Kayser, 1876, p. 6].
*Obolus sp. undt. e [ Kayser, 1876, p. 9]. Arionellus lorenzi [Kayser, 1876, p. 7].
Hyolithes sp. undt. [Kayser, 1876, p. 8]. Arionellus hyeronimi [Kayser, 1876, p. 7].

389c [Kayser, 1897, p. 280]. Upper Cambrian: Conglomeratic sandstone at Ojo de Agua, Province of Santiago
del Est, about 70 miles (112 km.) north of Cordova, Argentina, South America.
*Koorthis saltensis.

389d (references follow species). Upper Cambrian: At Iruya, Province of Salta, Argentina, South America.

Lingulella davisi [Kayser, 1897, p. 280]. Agnostus iruyensis [Kayser, 1897, p. 279].
Lingulella ferruginea [Kayser, 1897, p. 280]. Liostracus ulrichi [Kayser, 1897, p. 277].
Eoorthis saltensis [Kayser, 1897, p. 280]. Liostracus steinmanni [ Kayser, 1897, p. 277].

390 [U. S. National Museum]. (For stratigraphic position and association, see p. 144.) Passage beds between
the Upper Cambrian and the Ordovician: Boundary stratum between the Orthoceras limestone and Cera-
topyge limestone [Moberg and Segerberg, 1906, p. 69] at Alunbruk (alum works), southern part of Oeland
Island, Sweden.

*HKoorthis tullbergi.

390a [Moberg, 1892b, p. 112].. (For stratigraphic position and association, see p. 146.) Lower Cambrian: Drift
blocks of glauconitic quartzitic sandstone at several points near Stora Ror, Kalmar sheet (Geol. Survey
Sweden), Oeland Island, Sweden.

*Micromitra (Paterina) undosa.
Discinella.

390b (references follow species). (For stratigraphic position and association, see p. 145.) Upper Cambrian: Lime-

stone of the Shumardia zone (zone 3) at Fogelsing, 5 miles (8 km.) east of Lund, Province of Malméhus,

Sweden.
EKoorthis wimani [Moberg and Segerberg, 1906, p. 71]. Symphysurus angustatus [Moberg and Segerberg, 1906,
Trochus atavus [Moberg and Segerberg, 1906, desc. of Pl. desc. of Pl. V].
III]. Orometopus elatifrons? [Moberg and Segerberg, 1906, desc.
Shumardia celandica [Moberg and Segerberg, 1906, desc. of Pl. VII].
of Pl. IV].

Shumardia dicksoni [Moberg and Segerberg, 1906, desc.
of Pl. IV].

280 CAMBRIAN BRACHIOPODA.

390¢e (references follow species). (For stratigraphic position and association, see p. 145.) Upper Cambrian:
Ceratopyge slate (zone 3) at Wentlinge, Oeland Island, Sweden:

Eoorthis wimani [Moberg and Segerberg, 1906, p. 70]. Cyrtometopus primigenus [Moberg and Segerberg, 1906,
Beyrichia nanella [Moberg and Segerberg, 1906, desc. of desc. of Pl. VII].

TAL, INU
Shumardia celandica [Moberg and Segerberg, 1906, desc.

of Pl. LV].

390d [Moberg, 1892b, p. 112]. (For stratigraphic position and association, see p. 146.) Lower Cambrian: Drift
blocks of glauconitic quartzitic sandstone north of Rohilla, Kalmar sheet (Geol. Survey Sweden), Oeland
Island, Sweden.
Micromitra (Paterina) undosa. | Discinella.

390e [Moberg and Segerberg, 1906, pp. 7land 109]. (For stratigraphic position and associaticn, see p. 144.) Pas-
sage beds between the Upper Cambrian and the Ordovician: Apatocephalus zone of the Ceratopyge suite
at Ottenby, Oeland Island, Sweden. ;
Eostrophomena elegantula.

390f (U. S. National Museum). (For stratigraphic position and association, see p. 144.) Passage beds between
the Upper Cambrian and the Ordovician: Shales between the “lower graptolite slate” and the Ceratopyge
limestone at Mossebo, on Hunneberg, western boundary of the Province of Skaraborg, Sweden.
*Protorthis? hunnebergensis.

390g [Moberg and Segerberg, 1906, p. 64, and U.S. National Museum]. (See 309i.) (For stratigraphic position
and association, see p. 145.) Upper Cambrian: Limestone in the Dictyograptus slate at Sandby, 6 miles
(9.6 km.) east-northeast of Lund, Province of Malméhus, Sweden.
Obolus (Bréggeria) salteri. \

390h [Moberg, 1892b, p. 112]. (For stratigraphic position and association, see p. 146.) Lower Cambrian: Drift
blocks of glauconitic quartzitic sandstone on Nordmannaskir Island, Kalmar sheet (Geol. Survey Sweden),
Sweden.
Micromitra (Paterina) undosa.
Discinella.

390i (U.S. National Museum). (See310d.) (Forstratigraphic position and association, seep. 145.) Upper Cam- —

brian: Limestone band in the Ceratopyge slate at Borgholm, Oeland Island, Sweden.
Obolus (Bréggeria) salteri.

390j (references follow species). (Forstratigraphic position and association, seep.146.) Lower Cambrian: Hophyton
sandstone at Lugnas, 8 miles (12 km.) south-southwest of Mariestad, Province of Skaraborg, Sweden.

*Hyolithes levigatus [Linnarsson, 1871, p. 9]. Cruziana dispar [Linnarsson, 1869a, p. 353].
*Mickwitzia monilifera [U. 8. National Museum and | Eophyton linnzanum [Linnarsson, 1869b, p. 399].
Linnarsson, 1869a, p. 344]. *Eophyton torelli [Linnarsson, 1869a, p. 351].
*Mickwitzia pretiosa (U. S. National Museum). *Dictyonema sp. [Linnarsson, 1871, p. 13].
Arenicolites spiralis [Linnarsson, 1869b, p. 398]. *Astylospongia radiata [Linnarsson, 1871, p. 13].
Freena tenella [Linnarsson, 1871, p. 11]. *Bythotrephis sp. [Linnarsson, 1871, p. 18].
*Agelacrinus? lindstrémi [Linnarsson, 1871, p. 1]. Scotolithus mirabilis [Linnarsson, 1871, p. 18].

390k. @ (For stratigraphic position and association, see p. 146.) Lower Cambrian: Hophyton sandstone at Prestorp,
north of the hill of Billingen, southeast of Lake Vennern, Province of Skaraborg, Sweden.
Mickwitzia monilifera.
3901 [Moberg and Segerberg, 1906, p. 65]. (For stratigraphic position and association, see p. 145.) Upper Cam-
brian: Obolus conglomerate at Klittberget, in Dalarne, Province of Kopparberg, Sweden.
Obolus apollinis.

390m [Moberg and Segerberg, 1906, p. 65]. (For stratigraphic position and association, see p. 145.) Upper Cam-
brian: Conglomerate overlying a glauconite sand at Horn, northern part of Oeland Island, Sweden.
Obolus apollinis.

390n [U. 8. National Museum]. (For stratigraphic position and association, see p. 145.) Upper Cambrian: Lime-
stones of Olenws zone at Hunneberg, western boundary of the Province of Skaraborg, Sweden.
Orusia lenticularis.
Parabolina spinulosa.

8900 [U. S. National Museum]. (For stratigraphic position and association, see p. 145.) Upper Cambrian: Arena-
ceous shales at Andrarum, 20 miles (32 km.) northwest of Simrishamn, Province of Christianstad, Sweden.
Orusia lenticularis. (Von Buch [1834, p. 48] cites this species from ‘‘aluminiferous schists” at Andrarum, and the two
localities may be the same.)

‘a The authority for the citation of this locality was mislaid and could not be traced in time for insertion in this volume.

LOCALITIES. 281

390p [Davidson, 1869, p. 231]. (For stratigraphic position and association, see p. 145.) Upper Cambrian: At
Kinnekulle, northeast of Lidképing, Province of Skaraborg, Sweden.
Orusia lenticularis.

392 [U. S. National Museum]. Upper Cambrian: Potsdam sandstone at Burgess, Canada.
Lingulella (Lingulepis) acuminata.

392a [U.S. National Museum; see Walcott, 1891b, p. 254]. Lower Cambrian: Limestones at L’ Anse au Loup, on the
north shore of the Straits of Belleisle, Labrador.

Micromitra (Paterina) bella. Stenotheca elongata Walcott.
*Micromitra (Paterina) labradorica. Stenotheca rugosa (Hall).
*Obolella chromatica. Hyolithes billingsi Walcott.
*Kutorgina cingulata. Salterella pulchella Billings.
Nisusia festinata. Salterella rugosa Billings.
*Nisusia (Jamesella) sp. undt. Mesonacis vermontana (Hall).
Orthis 2 sp. Olenellus logani Walcott (Geol. Survey Canada).
Paleeophycus incipiens. Ptychoparia miser Billings.
Archzocyathus profundus (Billings). Protypus senectus Billings.
Spirocyathus atlanticus (Billings). Solenopleura (like S. nana Ford).
Coscinocyathus billingsi Walcott.

392b [Matthew, 1895b, p. 258]. Upper Cambrian: Sandstone at Beverly, township of Bastard, county of Leeds,
Ontario, Canada. This sandstone corresponds to the passage beds above the massive Potsdam sandstone at
Chateaugay Falls, New York.
Lingulella (Lingulepis) acuminata.

392c [Billings, 1872a, p. 218]. Lower Cambrian: At the Straits of Belleisle, Labrador.

*Bicia gemma. Obolella desquamata=Obolella crassa.
Obolella chromatica. Botsfordia ceelata.
Obolella crassa. Quebecia circe.

392d [Billings, 1856, p. 34]. Upper Cambrian: Sandstone on Lot 11, 11th concession, township of Lansdowne,
county of Leeds, Ontario, Canada.
Lingulella (Lingulepis) acuminata.

392e [Billings, 1856, p. 34]. Upper Cambrian: Sandstone on Lot 22, 9th concession, township of Bastard, county
of Leeds, Ontario, Canada.
Lingulella (Lingulepis) acuminata.

392g [Dawson, 1888a, p. 55]. Middle? Cambrian (probably between the Middle and Upper Cambrian): Black
shales at Little Metis, Province of Quebec, Canada.
Obolella ida=Acrotreta sagittalis.

392h [Billings, 1859, p. 432]. Ordovician: Limestone of the ‘‘Chazy formation” in the valley of Ottawa River,
above Carillon, Quebec, Canada.
Obolus belli.

392i [Billings, 1865a, p. 220]. Lower Ordovician: Limestone at Phillipsburgh, Province of Quebec, Canada.
Syntrophia calcifera.
Bathyurus saffordi.

392j [U. S. National Museum]. Lower Ordovician: Limestones of the ‘‘Quebec group” at Point Levis, Province of
* Quebec, Canada.
*Syutrophia calcifera.

3921 [Geological Survey of Canada]. Lower Cambrian: Arenaceous limestone at Point Amour, Straits of Belleisle,

Labrador.
Kutorgina cingulata. Discinella.
Obolella chromatica. Archeeocyathus.
Stenotheca cf. elongata Walcott. ° Olenellus sp.?.

392m [U. S. National Museum]. (See 392i.) Upper Cambrian: Sandstone on the east shore of Missisquoi Bay,
1.5 miles (2.4 km.) south of Phillipsburgh, Province of Quebec, Canada (C. D. Walcott, 1888).
Lingulella (Lingulepis) acuminata.

392n [U. S. National Museum]. Upper Cambrian: Sandstone in eastern Canada, exact locality unknown (Geol.
Survey Canada, 1876).
Lingulella (Lingulepis) acuminata.

282

3920 [U. S. National Museum].
locality unknown (T. C. Wooster).
Rustella edsoni.

392p [U. S. National Museum].
Nisusia festinata.

395 (references follow species).

CAMBRIAN BRACHIOPODA.

Lower Cambrian: Arenaceous limestone collected somewhere in Vermont, exact

Lower Cambrian: Shale on the Jewell farm, Franklin County, Vt.

(For stratigraphic position and association, see p. 143.) Upper Cambrian: Obolus

sandstone at Joa, near Jegelecht, 12 miles (19.3 km.) east of Reval, Government of Esthonia, Russia.

Obolus apollinis [Mickwitz, 1896, p. 137].

Obolus apollinis ingricus [Mickwitz, 1896, p. 139].

*Obolus apollinis maximus [Mickwitz, 1896, p. 144, and
U.S. National Museum].

*Obolus apollinis quenstedti [Mickwitz, 1896, p. 145].

*Obolus eichwaldi [Mickwitz, 1896, p. 155].

*Obolus elegans [Mickwitz, 1896, p. 158].

*Obolus panderi [Mickwitz, 1896, p. 151].

*Obolus schmidti [Mickwitz, 1896, p. 153].

*Obolus volborthi [Mickwitz, 1896, p. 157].

*Obolus (Schmidtia) acuminatus [Mickwitz, 1896, p. 183,
and U.S. National Museum].

*Obolus (Schmidtia) acuminatus alatus [Mickwitz, 1896,
p. 184].

*Obolus (Schmidtia) acuminatus humeratus [Mickwitz,
1896, p. 186].

Obolus (Schmidtia) acuminatus subtriangularis [Mick-
witz, 1896, p. 187].

Obolus (Schmidtia) celatus (U. S. National Museum).

395a (references follow species).

Obolus (Schmidtia) celatus preecisus [Mickwitz, 1896, p.
166].

*Obolus (Schmidtia) crassus [Mickwitz, 1896, p. 192, and
U.S. National Museum].

Obolus (Schmidtia) crassus angulatus [Mickwitz, 1896, p.
194}.

*Obolus (Schmidtia) obtusus [Mickwitz, 1896, p. 171, and
U.S. National Museum].

Obolus (Schmidtia) obtusus acutus [Mickwitz, 1896, p. 173].

Obolus (Schmidtia) obtusus ellipticus [Mickwitz, 1896, p.
178].

Obolus (Schmidtia) obtusus extenuatus [Mickwitz, 1896,
p. 177].

Obolus (Schmidtia) obtusus latus [Mickwitz, 1896, p. 175].

Obolus (Schmidtia) obtusus longus [Mickwitz, 1896, p. 172].

Obolus (Schmidtia) obtusus minutus [Mickwitz, 1896, p.
176].

Lingulella (Leptembolon) linguleeformis (U. S. National
Museum).

Keyserlingia buchi (U. S. National Museum).

(For stratigraphic position and association, see p. 143.) Upper Cambrian: Obolus

sandstone at Tihala, near Jegelecht, about 12 miles (19.3 km.) east of Reval, Government of Esthonia,

Russia.
Obolus apollinis ingricus [Mickwitz, 1896, p. 139].
Obolus apollinis quenstedti [Mickwitz, 1896, p. 144].

Obolus (Schmidtia) acuminatus humeratus [Mickwitz,
1896, p. 186].

Obolus (Schmidtia) acuminatus [Mickwitz, 1896, p. 183]. | Obolus (Schmidtia) celatus preecisus [Mickwitz, 1896, p.

Obolus (Schmidtia) acuminatus alatus [Mickwitz, 1896, p.
184].

166].
Obolus (Schmidtia) crassus [Mickwitz, 1896, p. 192].

395b (referencesfollowspecies). (For stratigraphic position and association, see p. 143.) Upper Cambrian: Obolus
sandstone at Ileast, Government of Esthonia, Russia.

Obolus apollinis (U. S. National Museum).

Obolus elegans (U. S. National Museum).

Obolus (Schmidtia) acuminatus [Mickwitz, 1896, p. 183].

Obolus (Schmidtia) acuminatus alatus [Mickwitz, 1896, p.
184].

Obolus (Schmidtia) acuminatus humeratus [Mickwitz,
1896, p. 186].

Obolus (Schmidtia) acuminatus subtriangularis [Mick-
witz, 1896, p. 187].

395c (references follow species).

Obolus (Schmidtia) celatus preecisus [Mickwitz, 1896, p.
166].

Obolus (Schmidtia) crassus [Mickwitz, 1896, p. 192].

Obolus (Schmidtia) crassus angulatus [Mickwitz, 1896, p.
194].

Obolus (Schmidtia) obtusus [Mickwitz, 1896, p. 171]. °

Obolus (Schmidtia) obtusus ellipticus [Mickwitz, 1896, p.
178].

Keyserlingia buchi (U. 8. National Museum).

(For stratigraphic position and association, see p. 143.) Upper Cambrian: Obolus

sandstone at Asserien, 75 miles (121 km.) east of Reval, Government of Esthonia, Russia.

Obolus (Schmidtia) acuminatus [Mickwitz, 1896, p. 183].

Obolus (Schmidtia) acuminatus alatus [Mickwitz, 1896, p.
184].

*Obolus (Schmidtia) celatus [Volborth, 1869, p. 212].

395d (references follow species).

Obolus (Schmidtia) celatus preecisus [Mickwitz, 1896, p.
166].
Obolus (Schmidtia) crassus [Mickwitz, 1896, p. 192].

(For stratigraphic position and association, see p. 143.) Upper Cambrian: Obolus

sandstone at Ontika, about 95 miles (153 km.) east of Reval and 30 miles (48 km.) west of Narwa, Govern-

ment of Esthonia, Russia.
Obolus (Schmidtia) acuminatus [Mickwitz, 1896, p. 183].
Obolus (Schmidtia) acuminatus alatus [Mickwitz, 1896, p.
184].

Obolus (Schmidtia) celatus preecisus [Mickwitz, 1896, p.
166].
Obolus (Schmidtia) crassus [Mickwitz, 1896, p. 192].

LOCALITIES. . 283

395e (references follow species). (For stratigraphic position and association, see p. 144.) Upper Cambrian: Obolus
sandstone at Isenhof, 85 miles (137 km.) east of Reval, Government of Hsthonia, Russia.
Obolus (Schmidtia) acuminatus [Mickwitz, 1896, p. 183]. | Obolus (Schmidtia) celatus precisus [Mickwitz, 1896, p.
Obolus (Schmidtia) acuminatus alatus [Mickwitz, 1896, p. 166].
184]. Obolus (Schmidtia) crassus [Mickwitz, 1896, p. 192].
395f [Mickwitz, 1896, p. 142]. (For stratigraphic position and association, see p. 144.) Upper Cambrian: Obolus
conglomerate throughout the East Baltic region, Government of Esthonia, Russia.
Obolus apollinis.
Obolus apollinis maximus.

395g (references follow species). (For stratigraphic position and association, see p. 144.) Upper Cambrian: Obolus
conglomerate at Joa, near Jegelecht, 12 miles (19.3 km.) east of Reval, Government of Esthonia, Russia.

*Obolus triangularis [Mickwitz, 1896, p. 147]. Obolus (Schmidtia) celatus orbiculatus [Mickwitz, 1896,

Obolus triangularis inornatus [Mickwitz, 1896, p. 149]. p. 165].

Obolus (Schmidtia) celatus [Mickwitz, 1896, p. 163]. Obolus (Schmidtia’ celatus preecisus [Mickwitz, 1896, p.
166].

395h (references follow species). Upper Cambrian: Obolus conglomerate at Tihala, near Jegelecht, about 12 miles
(19.3 km.) east of Reval, Government of Esthonia, Russia.
Obolus (Schmidtia) celatus [Mickwitz, 1896, p. 163].
Obolus (Schmidtia) celatus orbiculatus [Mickwitz, 1896, p. 165].
Obolus (Schmidtia) celatus preecisus [Mickwitz, 1896, p. 166].

395i (references follow species). (For stratigraphic position and association, see p. 144.) Upper Cambrian: Obolus
conglomerate at Ilgast, Government of Esthonia, Russia.

Obolus triangularis [Mickwitz, 1896, p. 147]. Obolus (Schmidtia) celatus preecisus [Mickwitz, 1896, p.
Obolus (Schmidtia) celatus [Mickwitz, 1896, p. 163]. 166].
Obolus (Schmidtia) celatus orbiculatus [Mickwitz, 1896,

p. 165].

395j (references follow species). (For stratigraphic position and association, see p. 144.) Upper Cambrian: Obolus
F conglomerate at Asserien, 75 miles (121 km.) east of Reval, Government of Esthonia, Russia.

Obolus (Schmidtia) celatus orbiculatus [Mickwitz, 1896, p. 165].

Obolus (Schmidtia) celatus preecisus [Mickwitz, 1896, p. 166].

395k (references follow species). (Forstratigraphic position and association, see p. 144.) Upper Cambrian: Obolus
conglomerate at Ontika, about 95 miles (153 km.) east of Reval and 30 miles (48 km.) west of Narwa, Goy-
ernment of Esthonia, Russia.
Obolus (Schmidtia) celatus orbiculatus [Mickwitz, 1896, p. 165].
Obolus (Schmidtia) celatus preecisus [Mickwitz, 1896, p. 166].

-8951 (references follow species). (For stratigraphic position and association, see p. 144.) Upper Cambrian: Obolus
conglomerate at Isenhof, 85 miles (137 km.) east of Reval, Government of Esthonia, Russia.
Obolus (Schmidtia) celatus orbiculatus [Mickwitz, 1896, p. 165].
Obolus (Schmidtia) celatus precisus [Mickwitz, 1896, p. 166].

395m (references follow species). (Forstratigraphic position and association, see p. 144.) Upper Cambrian: Sand-
stone below the Obolus conglomerate at Joa, near Jegelecht, 12 miles (19.3 km.) east of Reval, Government
of Esthonia, Russia.
Obolus (Schmidtia) celatus orbiculatus [Mickwitz, 1896, p. 165].
Obolus (Schmidtia) celatus preecisus [Mickwitz, 1896, p. 166].

395n (references follow species). (For stratigraphic position and association, see p. 144.) UpperCambrian: Sand-
stone below the Obolus conglomerate at Tihala, near Jegelecht, about 12 miles (19.3 km.) east of Reval,
Government of Esthonia, Russia.
Obolus (Schmidtia) celatus orbiculatus [Mickwitz, 1896, p. 165].
Obolus (Schmidtia) celatus preecisus [Mickwitz, 1896, p. 166].

3950 (references follow species). (For stratigraphic position and association, see p. 144.) Upper Cambrian: Sand-
stone below the Obolus conglomerate at Ilgast, Government of Esthonia, Russia.
Obolus (Schmidtia) celatus [Mickwitz, 1896, p. 163].
Obolus (Schmidtia) celatus orbiculatus [Mickwitz, 1896, p. 165].
Obolus (Schmidtia) celatus preecisus [Mickwitz, 1896, p. 166].

395p (references follow species). (For stratigraphic position and association, see p. 144.) Upper Cambrian: Sand-
stone below the Obolus conglomerate at Asserien, 75 miles (121 km.) east of Reval, Government of Esthonia,
Russia.
Obolus (Schmidtia) celatus orbiculatus [Mickwitz, 1896, p. 165].
Obolus (Schmidtia) celatus preecisus [Mickwitz, 1896, p. 166].

284 CAMBRIAN BRACHIOPODA.

395q (references tollow species). (For stratigraphic position and association, see p.144.) Upper Cambrian: Sand-
stone below the Obolus conglomerate at Ontika, about 95 miles (153 km.) east of Reval and 30 miles (48 km.)
west of Narwa, Government of Esthonia, Russia.
Obolus (Schmidtia) celatus orbiculatus [Mickwitz, 1896, p. 165].
Obolus (Schmidtia) celatus przecisus [Mickwitz, 1896, p. 166].

395r (references follow species). (For stratigraphic position and association, see p. 144.) Upper Cambrian:
Sandstone below the Obolus conglomerate at Isenhof, 85 miles (137 km.) east of Reval, Government of
Esthonia, Russia. :
Obolus (Schmidtia) celatus orbiculatus [Mickwitz, 1896, p. 165].
Obolus (Schmidtia) celatus preecisus [Mickwitz, 1896, p. 166].

395s [Mickwitz, 1896, p. 163]. (Forstratigraphic position and association, see p. 144.) UpperCambrian: Schmidtia
conglomerate (part of the Obolus conglomerate) at Asserien, 75 miles (121 km.) east of Reval, Government of

Esthonia, Russia.

Obolus (Schmidtia) celatus.

395t [Mickwitz, 1896, p. 163]. (Forstratigraphic position and association, seep. 144.) Upper Cambrian: Schmidtia
conglomerate (part of the Obolus conglomerate) at Ontika, about 95 miles (153 km.) east of Reval and 30
miles (48 km.) west of Narwa, Government of Esthonia, Russia.
Obolus (Schmidtia) celatus.

395u [Mickwitz, 1896, p.163]. (Forstratigraphic position and association, see p. 144.) UpperCambrian: Schmidtia
conglomerate (part of the Obolus conglomerate) at Isenhof, 85 miles (137 km.) east of Reval, Government of

Esthonia, Russia.

Obolus (Schmidtia) celatus.

395v [Eichwald, 1843, p. 147]. (For stratigraphic position and association, see p. 143.) Passage beds between the
Upper Cambrian and the Ordovician: Sandstone on Odensholm Island, about 55 miles (88.6 km.) west of
Reval, Government of Esthonia, Russia.
Obolus (Mickwitzella) siluricus.

395w [Hichwald, 1843, p. 147]. (For stratigraphic position and association, see p. 143.) Passage beds between the
Upper Cambrian and the Ordovician: In the chlorite-bearing sands in the limestone beds at Pawlowsk, near
St. Petersburg, Russia.
Obolus (Acritis) antiquissimus.
Obolus (Mickwitzella) siluricus.

395x [Lamansky, 1901, p. 617]. (For stratigraphic position and association, see p. 143.) Passage beds between the
Upper Cambrian and the Ordovician: Glauconitic sandstone (correlated by Lamansky, 1901, p. 617, with
the Upper Cambrian Ceratopyge slate) in the vicinity of Baltischport, about 30 miles (48 km.) west of
Reval, Government of Esthonia, Russia.
Obolus (Mickwitzella) siluricus.

395y [Kutorga, 1848, p. 281]. (For stratigraphic position and association, see p. 143.) Passage beds between the
Upper Cambrian and the Ordovician: Sandstone on Pulkowa Brook, near St. Petersburg, Russia.
Obolus (Mickwitzella) siluricus.

395z (references follow species). (Forstratigraphic position and association, see p. 143.) Upper Cambrian: Obolus
sandstone at Jamburg on Louga (Luga) River, Government of St. Petersburg, Russia.
*Obolus apollinis [Hichwald, 1829, p. 274, and U. 8. National Museum].
*Obolus apollinis ingricus [Hichwald, 1829, p. 274].
Obolus apollinis quenstedti [Mickwitz, 1896, p. 144].
396 (references followspecies). (For stratigraphic position and association, see p. 143.) Passage beds between the
Upper Cambrian and the Ordovician: ‘‘Glauconite eam dstene! at Baltischport, 30 miles (48 km.) west of
Reval, Government of Esthonia, Russia.
Obolus (Mickwitzella) siluricus [Mickwitz, 1896, p. 198, and U.S. National Museum].
Lingulella (Leptembolon) linguleeformis [Mickwitz, 1896, p. 203].

396a (references followspecies). (For stratigraphic position and association, see p. 143.) Passage beds between the
Upper Cambrian and the Ordovician: ‘‘Glauconite sandstone” at Leppiko, near Leetz, on the eastern side
of the Baltischport peninsula, about 25 miles (40.3 km.) west of Reval, Government of Esthonia, Russia.
*Obolus (Mickwitzella) siluricus [Mickwitz, 1896, p. 198, and U.S. National Museum].
*Lingulella (Leptembolon) linguleeformis [Mickwitz, 1896, p. 203, and U. S. National Museum].
*Lingulella (Leptembolon) linguleeformis solidus |Mickwitz, 1896, p. 205].
396b (references follow species). (For stratigraphic position and association, see p. 143.) Passage beds between
the Upper Cambrian and the Ordovician: ‘“‘Glauconite sandstone” at Fall, 15 miles (24 km.) west of Reval,
Government of Esthonia, Russia.
Obolus (Mickwitzella) siluricus [Mickwitz, 1896, p. 198].
Uingulella (Leptembolon) linguleeformis [Mickwitz, 1896, p. 203].

i

aS ee

mene

LOCALITIES. 285

396c (references follow species). (For stratigraphic position and association, see p. 143.) Passage beds between the
Upper Cambrian and the Ordovician: ‘‘Glauconite sandstone” at the mouth of Fiahna Brook, east of Fall,
about 15 miles (24 km.) west of Reval, Government of Esthonia, Russia.
Obolus (Mickwitzella) siluricus [Mickwitz, 1896, p. 198].
Lingulella (Leptembolon) linguleeformis [Mickwitz, 1896, p. 203].

396d (references follow species). (or stratigraphic position and association, see p. 143.) Passage beds between the
Upper Cambrian and the Ordovician: ‘‘Glauconite sandstone” at Domglint in Reval, Government of
Esthonia, Russia.
Obolus (Acritis) antiquissimus (U. S. National Museum).
Obolus (Acritis) antiquissimus ventrosus [?].
Lingulella (Leptembolon) lingulzeformis [Mickwitz, 1896, p. 203].

396e [Mickwitz, 1896, p. 198]. (For stratigraphic position and association, see p. 143.) Passage beds between the
Upper Cambrian and the Ordovician: ‘‘Glauconite sandstone”’ in the eastern part of the east Baltic region,
Government of Esthonia, Russia.
Obolus (Mickwitzella) siluricus.

396f [Mickwitz, 1896, p. 204]. (For stratigraphic position and association, see p. 143.) Passage beds between the
Upper Cambrian and the Ordovician: ‘‘Glauconite sandstone” in the western part of the east Baltic region,
Russia.
Lingulella (Leptembolon) linguleeformis.

396g [Hichwald, 1843, p. 143]. (For stratigraphic position and association, see p. 143.) Passage beds between the
Upper Cambrian and the Ordovician: In the upper limestone at Reval, Government of Esthonia, Russia.
*Obolus (Acritis) antiquissimus.

396h [Mickwitz, 1896, p. 213]. (For stratigraphic position and association, see p. 143.) Passage beds between the
Upper Cambrian and the Ordovician: “‘Glauconite limestone” at Tischer, 10 miles (16 km.) west of Reval,
Government of Esthonia, Russia.
Obolus (Acritis) antiquissimus.

396i [Mickwitz, 1896, p. 213]. (For stratigraphic position and association, see p. 143.) Passage beds between the
Upper Cambrian and the Ordovician: “Glauconite limestone” at Fall, 15 miles (24 km.) west of Reval,
Government of Esthonia, Russia.
Obolus (Acritis) antiquissimus.

396j [Mickwitz, 1896, p. 213]. (For stratigraphic position and association, see p. 143.) Passage beds between the
Upper Cambrian and the Ordovician: “Glauconite limestone” at Noémmeweske, near Palms, Government

of Esthonia, Russia.

Obolus (Acritis) antiquissimus.

396k [Mickwitz, 1896, p. 213]. (For stratigraphic position and association, see p. 143.) Passage beds between the
Upper Cambrian and the Ordovician: ‘‘Glauconite limestone” at Iswos on the Wolchow, Government of
St. Petersburg, Russia.
Obolus (Acritis) antiquissimus.

3961 [Mickwitz, 1896, p. 213]. (For stratigraphic position and association, see p. 143.) Passage beds between the
Upper Cambrian and the Ordovician: ‘‘Glauconite limestone” at Pulkowa, near St. Petersburg, Russia.
Obolus (Acritis) antiquissimus.

396m [Mickwitz, 1896, p. 213]. (For stratigraphic position and association, see p. 143.) Passage beds between
the Upper Cambrian and the Ordovician: ‘‘Lower lenticular layer” of the ‘‘glauconite limestone” at
Saggad, east of Palms, Government of Esthonia, Russia.
Obolus (Acritis) antiquissimus.

396n [Mickwitz, 1896, p. 213]. (For stratigraphic position and association, see p. 143.) Passage beds between
the Upper Cambrian and the Ordovician: White limestone between the ‘“‘glauconite limestone” and the
sandy representative of the ‘‘ Vaginatum limestone” at Leppiko, near Leetz, on the eastern side of the
Baltischport peninsula, about 25 miles (40.3 km.) west of Reval, Government of Esthonia, Russia.
Obolus (Acritis) antiquissimus. :

3960 [Mickwitz, 1896, p. 213]. (For stratigraphic position and association, see p. 143.) Passage beds between
the Upper Cambrian and the Ordovician: ‘‘Glauconite limestone” in the entire western part of the east
Baltic region, Government of Esthonia, Russia.
Obolus (Acritis) antiquissimus.

8396p [Mickwitz, 1896, p. 213]. (For stratigraphic position and association, see p. 148.) Passage beds between
the Upper Cambrian and the Ordovician: Strata between the “‘lower lenticular layer” and the ‘‘ Vaginatum
limestone” proper at Némmeweske, near Palms, Government of Esthonia, Russia.
Obolus (Acritis) antiquissimus.

286 CAMBRIAN BRACHIOPODA.

396q [Schmidt, 1888, p. 24]. (For stratigraphic position and association, see p. 144.) Lower Cambrian: Upper
boundary of the blue clay with the Fucoid sandstone (the “ Mickwitzia conglomerate” [Schmidt, 1888,
p. 24]), at Reval, Government of Esthonia, Russia.
Mickwitzia monilifera.

396r [Schmidt, 1888, p. 24]. (For stratigraphic position and association, see p. 144.) Lower Cambrian: In the
‘““apper strata” at Streitberg, near Reval, Government of Esthonia, Russia.
Mickwitzia monilifera.

396s [Schmidt, 1888, p. 24]. (For stratigraphic-position and association, see p. 144.) Lower Cambrian: In loose
blocks on Kosch Brook near Likkat, near Reval, Government of Esthonia, Russia.
Mickwitzia monilifera.

396t [Schmidt, 1888, p. 24]. (For stratigraphic position and association, see p. 144.) Lower Cambrian: At the
sandstone capes of Ziegelskoppel, Kakkomaggi (also Rocca al Mare), near Reval, Government of Esthonia,
Russia.
Mickwitzia monilifera.

396u [Schmidt, 1888, p. 24]. (For stratigraphic position and association, see p. 144.) Lower Cambrian: In loose
blocks on the lower course of Jaggowal Brock, about 20 miles (32.2 km.) east-southeast of Reval, Govern-
ment of Esthonia, Russia.
Mickwitzia monilifera.
Traces of Olenellus.

396v [Schmidt, 1888, p. 24, and U.S. National Museum]. (For stratigraphic position and association, see p. 144.)
Lower Cambrian: At the upper boundary of a dolomitic sandstone with which the Olenellus stratum
begins, below the cement factory on Kunda Brook, Government of Esthonia, Russia.

Mickwitzia monilifera.
Traces of Olenellus.

396w [Schmidt, 1888, p. 24]. (For stratigraphic position and association, see p. 144.) Lower Cambrian: In the
glauconitic sands above the main mass of the clay, below the cement factory on Kunda Brook, Govern-
ment of Esthonia, Russia.
Mickwitzia monilifera.

396x [Eichwald, 1848, p. 146]. (For stratigraphic position and association, see p. 143.) Passage beds between
the Upper Cownibnten and the Ordovician: In the chlorite-bearing sands i in the limestone beds at Baltisch-
port, about 30 miles (48 km.) west of Reval, Government of Esthonia, Russia.
Obolus (Acritis) antiquissimus.
Obolus (Mickwitzella) siluricus.

396y [Hichwald, 1843, p. 147]. (For stratigraphic position and association, see p. 143.) Passage beds between
the Upper Cambrian and the Ordovician: In the chlorite-bearing sands in the limestone beds at Reval,
Government of Esthonia, Russia.
Obolus (Acritis) antiquissimus.
Obolus (Mickwitzella) siluricus.”

396z [Kutorea, 1848, p. 283]. (See 336g.) (For stratigraphic position and association, see p. 143.) Passage beds
between the Upper Cambrian and the Ordovician: Limestone in the vicinity of Zarskoe Selo, Covenant
of St. Petersburg, Russia.
Obolus (Acritis) antiquissimus.

Localities C1-C75, Carnegie Institution of Washington Expedition to China.4

C1 (just above C4, same section; just below C2, same section; about 75 feet below C62, which occurs at a locality
3 miles east; about same horizon as C10, different section; about 150 feet below C12, same section).
Middle Cambrian: Lower shale member of the Kiulung group [Blackwelder, 1907a, pp. 37 and 40 (part of
the third list of fossils), and fig. 10 (bed 4), p. 38], 2 miles (3.2 km.) south of Yenchuang, Sintai district,
Shantung, China (Eliot Blackwelder, 11-27-1908).

*Obolus minimus. Dorypyge richthofeni Dames.
Obolus (Westonia) blackwelderi. Inouyia divi (Walcott).

Acrotreta pacifica. Anomocarella albion Walcott.
Acrotreta shantungensis?. Anomocarella chinensis Walcott.
Protospongia chloris Walcott. Lisania agonius (Walcott).
Platyceras chronus Walcott. i Dolichometopus alceste Walcott?.
Hyolithes cybele Walcott. Dolichometopus decerto Walcott.
Agnostus chinensis Dames. Dolichometopus deois Walcott.

a See the explanatory paragraphs on pp. 160-161.

oe Set ee. peg Ae Se eto

LOCALITIES. oer

C2 (above (4, same section; just above Cl, same section; about same horizon as C10, different section). Middle
Cambrian: Lower shale member of the Kiulung group [Blackwelder, 1907a, pp. 37 and 40 (part of the third
list of fossils), and fig. 10 (beds 4 and 5), p. 38], 2 miles (3.2 km.) south of Yenchuang, Sintai district,
Shantung, China (Eliot Blackwelder, 11-30-1903).

Obolus (Westonia) blackwelderi.
Acrotreta pacifica.

Protospongia chloris Walcott.
Hyolithes cybele Walcott.
Orthotheca cyrene dryas Walcott.
Agnostus chinensis Dames.
Dorypyge bispinosa Walcott.
Anomocare latelimbatum Dames.

Anomocarella albion Walcott.
Anomocarella biston (Walcott).
Anomocarella chinensis Walcott.
Coosia? daunus (Walcott).
Lisania agonius (Walcott).
Dolichometopus derceto Walcott.
Dolichometopus deois Walcott.
Lonchocephalus tellus (Walcott).

C3 (about 100 feet above the horizon of O60, different section; about 175 feet below the horizon of C8, different
sections). Lower Cambrian: Lower part of the Manto shale formation [Blackwelder, 1907a, p. 28 (list of
fossils at bottom of page), and fig. 8a (bed 20), p. 28], on the southeast slope of Hulushan, 2.5 miles (4 km.)
southwest of Yenchuang, Sintai district, Shantung, China (Eliot Blackwelder, 11-30-1903).

*Billingsella richthofeni.
Stenotheca rugosa chinensis Walcott.
Hyolithes delia Walcott.

Redlichia nobilis Walcott.
Ptychoparia (Emmrichella) constricta (Walcott.)

C4 (just below Cl, same section; same horizon as C57, different section). Middle Cambrian: In limestone nodules
at the base of the lower shale member of the Kiulung group [Blackwelder, 1907a, pp. 37 and 40 (second list
of fossils), and fig. 10 (bed 4), p. 38], 3 miles (4.8 km.) southwest of Yenchuang, Sintai district, Shantung,

China (Eliot Blackwelder, 11-27-1903).
*Acrothele matthewi eryx.
Acrotreta pacifica.
Protospongia chloris Walcott.
Platyceras chronus Walcott.
Hyolithes cybele Walcott.
Orthotheca delphus Walcott.

Agnostus chinensis Dames.
Anomocarella albion Walcott.
Anomocarella chinensis Walcott.
Lisania alala (Walcott).
Dolichometopus alceste Walcott.
Dolichometopus deois Walcott.

C5 (about 25 feet above C8, same section; about 40 feet below C63, same section). Middle Cambrian: Lower lime-
stone member of the Kiulung group [Blackwelder, 1907a, pp. 37 and 39 (first list of fossils), and fie. 8a
(bed 30), p. 29], 3.2 miles (5.1 km.) southwest of Yenchuang, Sintai district, Shantung, China (Eliot
Blackwelder, 11-23-1903). On the figure this bed is placed as occurring below the line dividing the Manto
from the Kiulung, but on the basis of the fauna contained in the limestone it is referred to the base of the
Kiulung. The text (p. 39) places the boundary between the Kiulung and the Manto, 15 feet below C5.

Micromitra (Iphidella) pannula ophirensis.
*Acrotreta pacifica.

Globigerina? mantoensis Walcott.

Inouyia divi (Walcott).

Anomocare butes Walcott.
Anomocare sp.
Dolichometopus sp.

C6 (about 120 feet above C12, same section; about 20 feet below C61, same section). Middle Cambrian: Thin
platy limestone in the upper shale member of the Kiulung group just below the Chaumitien limestone
[Blackwelder, 1907a, pp. 37 and 41 (second list of fossils), and fig. 10 (bed 12), p. 38], 2.5 miles (4 km.)
southwest of Yenchuang, Sintai district, Shantung, China (Eliot Blackwelder, 11-25-1903).

*Acrothele minuta.

*Obolus (Westonia) blackwelderi.
*Dicellomus parvus.

Agnostus douvillei Bergeron.

Blackwelderia sinensis (Bergeron).

Drepanura ketteleri Monke.

Drepanura premesnili Bergeron. :
Ptychoparia (Emmrichella) bromus (Walcott).

Redlichia sp. undt. Walcott.
Shantungia spinifera Walcott.
Stephanocare? monkei Walcott.
Stephanocare richthofeni Monke.
Stephanocare sinensis (Bergeron).
Stephanocare? sp. undt. Walcott.
Liostracina krausei Monke.

C7 (just above C9, same section; about same horizon as C52, different sections; about 200 feet below C10, same
section). Middle Cambrian: Lower limestone member of the Kiulung group [Blackwelder, 1907a, pp.
37 and 39 (last list of fossils), and fig. 8a (bed 33), p. 29], 2.2 miles (3.5 km.) southwest of Yenchuang,
Sintai district, Shantung, China (Eliot Blackwelder, 11-23-1903).

Lingulella damesi.
Lingulella (Lingulepis) eros.
Inouyia abaris (Walcott).
Inouyia titiana (Walcott).

Agraulos dolon Walcott.
Anomocarella subrugosa (Walcott).
Anomocarella thraso ( Walcott.)

288 CAMBRIAN BRACHIOPODA.

9 (just below O7, same section; about 25 feet above C63, same section; about same horizon as C52, different sec-
tions). Middle Cambrian: Lower limestone member of the Kiulung group [Blackwelder, 1907a, pp. 37
and 39 (third list of fossils), and fig. 8a (bed 33), p. 29], 3 miles (4.8 km.) southwest of Yenchuang, Sintai
district, Shantung, China (?, 11-27-1903).

*Micromitra (Paterina) labradorica orientalis. Coosia decelus (Walcott).
Inouyia abaris (Walcott). Anomocare minus Dames.

€10 (about 200 feet above C7, same section; about same horizon as Cl, C2, and C4, different section). Middle
Cambrian: Lower shale member of the Kiulung group [Blackwelder, 1907a, pp. 37 and 40 (part of the third
list of fossils), and fig. 8a (bed 35), p. 29], about 3 miles (4.8 km.) southwest of Yenchuang, Sintai district,
Shantune, China (Eliot Blackwelder, 11-23-1903).
*Lingulella damesi.
Anomocarella temenus (Walcott).
Menocephalus sp. undt. Walcott.

C12 (about 120 feet below C6, same section; about 75 feet above C62, same section but at a locality 3 miles east;
013 includes the horizon represented by C12; about 150 feet above Cl, same section). Middle Cambrian:
Gray limestone near the top of the middle limestone member of the Kiulung group [Blackwelder, 1907a,
pp. 37 and 41 (part of first list of fossils), and fig. 10 (bed 7), ‘p. 38], 3.25 miles (5.2 km.) southwest: of
Yenchuang, Sintai district, Shantung, China (Eliot Blackwelder and Li San, 11-25-1903).

Acrotreta pacifica. Blackwelderia alastor (Walcott).
Tnouyia acalle (Walcott). Anomocarella tutia (Walcott).
Lisania ajax (Walcott). s Pterocephalus asiatica Walcott.
Damesella blackwelderi Walcott. Teinistion alcon (Walcott).

€17 (about 180 feet below 023, same section; about 35 feet above C20, adjacent sections; about 160 feet below C28,
adjacent sections). Lower Cambrian: Ferruginous limestone nodules in the brown sandy shales at the top
of the Manto shale [Blackwelder, 1907a, p. 27 (list of fossils at top of page) and fig. 6 (bed 15), p. 25], at
Changhia, Shantung, China (Eliot Blackwelder, 10-31-1903).
Obolella asiatica. Ptychoparia impar Walcott.
Ptychoparia aclis Walcott. Ptychoparia granosa Walcott.

€20 (about 15 feet above C31, same section; about 35 feet below C17, different sections). Lower Cambrian: Central
part of the Manto shale formation [Blackwelder, 1907a, p. 26 (last list of fossils) and fig. 6 (bed 14), p. 25],
on the west side of an isolated butte 1 mile (1.6 km.) south of Changhia, Shantung, ‘China (Eliot Black-
welder, 10-27-1903).
Billingsella richthofeni?.
Ptychoparia aclis Walcott.
Ptychoparia (Emmrichella) mantoensis (Walcott).

€22 (about same horizon as C19, C24, and C26, same section; above C18, same section). Middle Cambrian: Chang-
hia limestone in upper oolitic portion [Blackwelder, 1907a, pp. 22 and 33 (part of last list of fossils)], at
Changhia, Shantung, China (Eliot Blackwelder, 10-29-1903).

*Acrotreta lisani. Lisania bura (Walcott).
Hyolithes cybele Walcott. ! Menocephalus admeta Walcott.
Anomocarella temenus (Walcott). Menocephalus acantha (Walcott).

Lisania alala (Walcott).

€23 (about 180 feet above C17, same section; about 25 feet above O28, different sections). Middle Cambrian:
Upper part of thin-bedded eray oolitic limestone at the base of the Changhia formation [Blackwelder,
1907a, p. 32 (second list of fossils) and fig. 6 (bed 20), p. 25], 50 feet below the base of the cliffs 1 mile (1.6
km.) east-southeast of Changhia, Shantung, China (Eliot Blackwelder, 10-27-1903).
Acrothele rara?. Anomocarella tatian (Walcott).
Orthotheca daulis Walcott. Ptychoparia (Emmrichella) eriopia (Walcott).
Agraulos abrota Walcott. Ptychoparia (Emmrichella) theano (Walcott).

€24 (about same horizon as C19, 022, and ©26, same section; above C18, same section; about same horizon as

(25, different section). Middle Cambrian: Near top of black oolitic group in the uppermost layers of the!

Changhia formation [Blackwelder, 1907a, p. 33 (part of last list of fossils)], 2 miles (3.2 km.) east of Changhia,
Shantung, China.
Acrotreta cf. pacifica.
Agnostus sp. undt.
Inouyia divi (Walcott).

Dolichometopus dirce Walcott.
Dorypyge richthofeni Dames.

LOCALITIES. 289

€26 (about same horizon as C19, C22, and C24, same section; above C18, same section). Middle Cambrian: Upper
portion of the Changhia limestone, near top of black oolitic group [Blackwelder, 1907a, p. 33 (part of
last list of fossils)], 2 miles (3.2 km.) north-northeast of Changhia, Shantung, China (Eliot Blackwelder,
10-29-1903).
Eoorthis sp. undt.
Anomocare? daulis Walcott.
Crepicephalus damia Walcott.

€28 (about 200 feet above C20, same section; about 160 feet above C17, adjacent sections; about 25 feet below C23,
different sections). Middle Cambrian: Thin-bedded oolitic limestone at the base of the Changhia lime-
stone [Blackwelder, 1907a, p. 32 (first list of fossils) and fig. 6 (bed 20), p. 25], just above the shales in the
face of the cliff 1 mile (1.6 km.) east-southeast of Changhia, Shantung, China (Eliot Blackwelder, 10-29-1903).
*Hoorthis agreste. Inouyia thisbe Walcott.
Anomocarella tenes (Walcott). Bathyuriscus.
Anomocarella toxeus (Walcott).

€32 (see also C32’, other drift blocks at the same locality). Middle Cambrian: A fine-grained bluish-black lime-
stone bowlder believed to have come from the lower part of the Kisinling limestone [Blackwelder, 1907b,
p. 272], collected in river drift 1 mile (1.6 km.) south of Chonpinghien, on Nankiang River, southern
Shensi, China (Bailey Willis and Eliot Blackwelder, 5-28-1904).

Obolus shansiensis. Aluta enyo (Walcott).
Dicellomus parvus. Aluta eris (Walcott).
Acrotreta shantungensis. Aluta fragilis (Walcott).
Orthotheca doris Walcott. Aluta sterope (Walcott).
Microdiscus orientalis Walcott. Aluta woodi (Walcott).

Aluta bergeroni (Walcott).

C32/ (see C32, another drift block at the same locality). Lower Cambrian: A limestone bowlder collected in river
drift 1 mile (1.6 km.) south of Chonpinghien, on Nankiang River, southern Shensi, China (Bailey Willis
and Eliot Blackwelder, 5-28-1904).
*Obolella asiatica.
Hyolithes sp. undt.

C36 (about same horizon as C45, different section; about same horizon as C50, same section; above C68, same
section; about same horizon as C47, same section). Upper Cambrian: Upper part of the Chaumitien
limestone [Blackwelder, 1907a, p. 36 (part of third list of fossils), and fig. 9 (bed 2), p. 35], at Chaumitien,
Changhia district, Shantung, China (Eliot Blackwelder, 10-22-1903).

Billingsella pumpellyi. :
Anomocarella baucis Walcott.

C37 (about same horizon as C72, same section; about 50 feet above O71, same section; about 200 feet below 073,
same section; about 225 feet below C74, same section). Middle Cambrian: Upper part of the Kichou lime-
stone, in dense black limestone nodules in green-gray shales 10 feet below the base of the cliff limestone,
8 miles (12.8 km.) south of Tinghianghien, Shansi, China (Eliot Blackwelder, 2-24-1904). The fossils
from this locality are not listed, but the presence of Cambrian strata at the locality is mentioned by Willis

Z and Blackwelder [1907, p. 146].
*Obolus shansiensis.

Acrotreta shantungensis.

Anomocare megalurus (Walcott).

C54 (same horizon as C41, C49, and C56; about same horizon as C34 and ©38, different sections). Upper Cam-
brian: Lower part of Chaumitien limestone [Blackwelder, 1907a, p. 42 (part of last list of fossils)], near top
of limestone knoll 0.66 mile (1.1 km.) west of Tsinan, Shantung, China (Eliot Blackwelder, 116-1903).

*Obolus matinalis?. Illepurus sp. undt.

Eoorthis pagoda. Pterocephalia busiris Walcott.
Syntrophia orthia. Ptychaspis ceto Walcott.
Illzenurus canens Walcott. Ptychaspis sp. undt.

62667°—vot 51, pr 1—_12-——_19

290 CAMBRIAN BRACHIOPODA.

C56 (same horizon as 041, C49, and C54). Upper Cambrian: Lower part of Chaumitien limestone 25 feet below
the top of Pagoda Hill [Blackwelder, 1907a, p. 42 (part of last list of fossils)], 1 mile (1.6 km.) west of
Tsinan, Shantung, China (Eliot Blackwelder and Li San, 11—-6-1903).

*Obolus (Westonia) sp. undt. a.

*Discinopsis? sulcatus.

Acrotreta (dorsal valve resembling that of A. pacifica).
*Hoorthis pagoda.

*Syntrophia orthia,

Scenella sp. undt. Walcott.

Platyceras pagoda Walcott.

Straparollina circe Walcott.

Orthotheca sp. undt. Walcott.

Cyrtoceras cambria Walcott.
Menocephalus depressus Walcott.
Pagodia bia Walcott.

Pagodia lotos Walcott.
Ptychaspis ceto Walcott.
Conocephalina dryope (Walcott).
Conocephalina belus (Walcott).
Ileenurus dictys Walcott.
Hysterolenus?.

C57 (same horizon as C4, different section; below C11, same section; above C58, same section). Middle Cambrian:
In limestone nodules in the lower shale member of the Kiulung group [Blackwelder, 1907a, pp. 37 and 40
(first list of fossils)], 3 miles (4.8 km.) south of Kaokiapu and 4 miles (6.4 km.) north of Sintaihien, Sintai

district, Shantung, China (?, 11-21-1903).
*Acrothele rara.
Orthotheca delphus Walcott.
Agnostus chinensis Dames.
Agnostus kushanensis Walcott.
Dorypyge richthofeni Dames.

Anomocare alcinoe Walcott.
Anomocarella albion Walcott.
Anomocarella chinensis Walcott.
Dolichometopus deois Walcott.

C61 (about 25 feet above C6, same section; about same horizon as C11, different section; about 125 feet below
C64, same section). Uses Cambrian: A dense black limestone in the uppermost limestone member of the
lloras group [Blackwelder, 1907a, pp. 37 and 41 (third list of fossils), and fig. 10 (bed 13), p. 38], 3 miles
(4.8 km.) southwest of Yenchuang, Sintai district, Shantung, China (Li San, 11-23-1903).

*Billingsella pumpellyi.
Ptychaspis baubo (Walcott).
Proampyx burea Walcott.

Pterocephalia busiris Walcott.
Chuangia batia Walcott.
Chuangia fragmenta Walcott.

C62 (about 75 feet above Cl, which occurs at a locality 3 miles east; about 75 feet below C12 and C13, same section).
Middle Cambrian: Earthy layer in the middle limestone of the Kiulung group [Blackwelder, 1907a, pp. 37
and 40 (last list of fossils), and fig. 10 (base of bed 7), p. 38], 2.5 miles (4 km.) south of Yenchuang, on the
north-northeast spur of Hulushan, Sintai district, Shantung, China (Li San, 11-29-1903).

*Obolus chinensis.
*Acrotreta shantungensis Walcott.

Hyolithes cybele Walcott.
Anomocarella chinensis Walcott.

C63 (about 40 feet above C5, same section; about 25 feet below C9, same section). Middle Cambrian: Sandy shale
near the base of the Kiulung group [Blackwelder, 1907a, p. 37 (third paragraph), and fig. 8a (bed 32), p. 29],
3.5 miles (5.6 km.) southwest of Yenchuang, Sintai district, Shantung, China (Eliot Blackwelder, 11-27-1903).

*Obolus obscurus.

C64 (about 125 feet above C61, same section). Upper Cambrian: Upper limestone member of the Kiulung group
[Blackwelder, 1907a, pp. 37 and 42 (first list of fossils), and fig. 10 (bed 20), p. 38], 2.7 miles (4.3 km.) south-
west of Yenckuang, Sintai district, Shantung, China (Eliot Blackwelder, 11-25-1903).

Lingulella damesi?.
*Eoorthis doris.

*Hoorthis kayseri.

Eoorthis linnarssoni.
*Huenella orientalis.
Syntrophia orthia.
Hyolithes daphnis Walcott.
Orthotheca cyrene Walcott.
Anomocare sp.

Coosia bianos (Walcott).

Ptychaspis baubo (Walcott).
Ptychaspis cacus Walcott.
Ptychaspis callisto Walcott.
Ptychaspis calyce Walcott.
Ptychaspis ceto Walcott.
Ptychaspis sp.

Chuangia batia Walcott.
Chuangia nais Walcott.
Solenopleura beroe Walcott.

€67 (supposed to be from horizon of ©36, 045, C47, C50, and C68). Upper Cambrian: Stream gravels taken from
the wash from the mountains south of the city and used in making the railroad grade, 0.33 mile (0.5 km.)
west of the west city gate at Tsinan, Shantung, China (Eliot Blackwelder, 10-15-1903).

Obolus cf. matinalis.
Eoorthis ef. linnarssoni.
Ptychaspis sp. undt. Walcott.

C68 (same horizon as C47 and C50, same section; below C36, same section; about same horizon as C45, different
section). Upper Cambrian: Upper part of the Chaumitien limestone [Blackwelder, 1907a, p. 36 (part of
third list of fossils)] on crest of ridge east of Chaumitien, 200 yards north of the wayside shrine, Changhia
district, Shantung, China (Eliot Blackwelder, 10-25-1903).

Acrotreta (dorsal valve resembling that of A. pacifica).
Boorthis kayseri.

TERMINOLOGY. 291

C70 (35 feet below C69, same section). Middle Cambrian: Oolitic limestone about 30 feet above the base of the
Kichou limestone [Willis and Blackwelder, 1907, p. 144, last list of fossils], 4 miles (6.4 km.) south-south-
west of Tungyu, Shansi, China (Eliot Blackwelder, 2-21-1904).

Obolus sp. undt. Inouyia capax (Walcott).
Scenella? dilatatus Walcott ~ Inouyia melie (Walcott).
Stenotheca? simplex Walcott. Conocephalina maia (Walcott).
Agraulos vicina Walcott. Conocephalina sp.

C71 (about 50 feet below the horizon of C37 and C72, same section; about 125 feet above O75, different section).
Middle Cambrian: Massive cliff-making limestone in the central portion of the Kichou formation [Willis
and Blackwelder, 1907, pp. 139 and 145 (second list of fossils)], 4 miles (6.4 km.) southwest of Tungyu,
Shansi, China (Bailey Willis and Hliot Blackwelder, 2-21-1904).

Obolus aJhomenernstis?. Dorypyge richthofeni levis Walcott.
. Acrotreta shantungensis. Anomocarella bigsbyi (Walcott).
*Yorkia? orientalis. Anomocarella comus (Walcott).
EKoorthis sp. undt. Anomocarella undata (Walcott).
Orthotheca glabra Walcott. Solenopleura pauperata Walcott.
Agnostus chinensis Dames. Crepicephalus damia Walcott.

C72 (about same horizon as C37, same section; about 50 feet above C71, same section; about 200 feet below C73,
same section; about 225 feet below C74, same section). Middle Cambrian: Thin green-sray limestone
interbedded with ocherous and green clay shales overlying the massive oolite in the Kichou formation
[Willis and Blackwelder, 1907, pp. 189 and 145 (third list of fossils)], 4 miles (6.4 km.) east of Fanglanchon,
Shansi, China (Eliot Blackwelder, 2-22-1904).

Obolus sp. undt. Dorypyge richthofeni levis Walcott.
*Lingulella (Lingulepis?) sp. undt. Anomocare flava Walcott.
Platyceras willisi Walcott. Ptychoparia nereis Walcott.
Orthotheca glabra Walcott. Conocephalina sp. undt. (Walcott).

C74 (about 225 feet above the horizon of C37 and C72, same section; about 25 feet above 073, same section). Upper
Cambrian: A dense blue dolomitic limestone at the top of the Kichou limestone [Willis and Blackwelder,
1907, pp. 139 and 145 (fifth list of fossils)], 4 miles (6.4 km.) east of Fanglanchon, Shansi, China (Eliot
Blackwelder, 2-22-1904).
Eoorthis kayseri.
Ptychaspis bella Walcott.

C75 (about 125 feet below O71, different sections). Middle Cambrian: Limestone near the base of the Kichou

formation [Willis and Blackwelder, 1907, p. 143], 4.5 miles (7.2 km.) south of Wutaihien, Shansi, China
(Eliot Blackwelder, 2-13-1904).

Obolus obscurus. TInouyia melie (Walcott).
*Eoorthis kichouensis. Agraulos nitida Walcott.
Coscinocyathus elvira Walcott. Agraulos uta Walcott.
Tnouyia armatus (Walcott). Ptychoparia lilia Walcott.

ZOOLOGICAL DISCUSSION.

The zoological relations of the Cambrian Brachiopoda, or their consideration from the
paleozoologist’s standpoint, are discussed under four general headings: (1) Characters of the
shells, including the terminology adopted in describing them; (2) distribution in Cambrian
strata; (3) evolution; and (4) classification. Under Suiion no general description of the
evolution of the Br nelnfoynad, is attempted, nor is the life history of the living species treated.
The discussion is limited to certain observations on the Cambrian species and genera that
appear to add to our general knowledge of the subject.

TERMINOLOGY.
GENERAL STATEMENT.

Except for the muscle scars of the inarticulate brachiopods, the terms used in the descrip-
tion of genera and species are largely those defined by Schuchert [1897, pp. 73-75]. For the
Atremata and Neotremata the terminology proposed by William King [1873, pp. 5 and 6] is
adopted, and for the Protremata that used by Hall and Clarke [1892a, pp. 183-188] and given

292 CAMBRIAN BRACHIOPODA.

under the terminology of Schuchert [1897, pp. 73-77]. I agree with Hall and Clarke [1892c.
p- 21] that the terminology of the English authors has claims for its adoption. F. Bloch-
mann [1900, p. 108] has proposed a set of terms for the muscles of the inarticulate brachiopods
that has much to commend it. The terminology of Albany Hancock [1859, p. 800] has been
extensively used by authors. The numbers in this correspond to the numbers given the termi-
nology of King, Schuchert, and Blochmann.

Terminology of Hancock [1859, p. 800}.

Inarticulates: Articulates:
1. Anterior occlusors. 1. Anterior occlusors. _
2. Posterior occlusors. 2. Posterior ocelusors.
3. Divaricator. 3. Accessory divaricators.
4. Central adjustors. 4, ;
5. External adjustors. 5 | Ventral adjuster:
6. Posterior adjustors. 6. Dorsal adjustors.
7. Peduncular. 7. Peduncular.

Terminology of King [18738, pp. 5-6].

1. Anterior lateral. 4. Transmedians.

2. Centrals. 5. Outside laterals.

3. Umbonal. 6. Middle laterals.

Terminology of Schuchert [1897, pp. 78-75].

1. Retractors. 5. Protractors (externals).

2. Adductors. 6. Protractors (middles).

3. Pedicle. 7. Diductors.

4. Rotators.

Terminology of Blochmann [1900, p. 108].

1. Lateralis. ‘ 4. Obliquus internus.

2. Occlusor anterior. 5. Obliquus externus.

3. Occlusor posterior. 6. Obliquus medius.

DEFINITIONS.

Adductor muscles (see Central muscles)—The term adductor is used in the description of
the muscles of the Protremata.

Anterior lateral (retractor) muscles.—In the Atremata these extend from the outer lateral
margins of the visceral area in the ventral valve to its anterior extremity in the dorsal valve,
and serve to readjust the dorsal shell.

Anterior region.—That portion of the shell in front of the transverse axis and opposite
the pedicle opening.

Apex.—The place of initial shell growth. It may be the most posterior portion of the
valve or it may be situated near the transverse axis.

Apical callosity—The thickened boss at the inner side of the apex of the ventral valve
of Acrotreta and other neotrematous genera, through which the pedicle tube or foramen passes.

Area.—See Cardinal area. |

Articulate brachiopods.—In the orders Protremata and Telotremata the valves articulate
by means of teeth and sockets. In some Atremata rudimentary articulation is also developed.
(See p. 307.)

Atremata.—Primitive inarticulate caleareophosphatic brachiopods with the pedicle emerg-
ing more or less freely between the two valves. For a more detailed description see ‘‘Classifi-
cation of Cambrian Brachiopoda,” page 321.

Brachia.—The fleshy, coiled or spiral, ciliated appendages of brachiopods serving in
water circulation and respiration.

Brachiocwle.—All of the anterior half of the valves outside of the anterior portion of the
parietal band. (After King.)

Cardinal area.—A more or less well developed triangular area on each side of the delthy-
rium, distinctly set off from the general surface of the shell. It is best developed on the ventral

|

TERMINOLOGY. 293

valve of articulate brachiopods, but is also present on the dorsal valve, and generally ina
rudimentary condition in many inarticulate species. When the area is rudimentary it is often
called a false or pseudo-area (PI. II, figs. 1 and 7a; Pl. III, figs. 2a and 6b; Pl. V, figs. 1d at a;
Pl. VI, figs. 1’ and 3b). The area of some of the inarticulate genera is frequently divided by
a line between the delthyrium and the outer margin; in such areas the line is called the flexure
line, owing to the slight interruption in the striz of growth (Pl. VIII, fig. 1d at f), and the
spaces separated by the flexure line are called the imner and outer lateral spaces of the area.
(See Deltidium and Foramen, and p. 303.)

Cardinal extremities.—The terminations of the hinge line.

Cardinal muscle scar.—A large scar within vplnieln the posterior, anterior lateral, and
transmedian muscles were attached.

Cardinal process—A variously modified apophysis situated posteriorly at the center of
the hinge of the dorsal valve in articulate brachiopods. To it are attached the diductor
muscles, which by their contraction serve to open the valves anteriorly. (See p. 306.)

Cardinal siopes.—The inclined surfaces extending from the umbonal slopes to the hinge
margins.

Central (adductor) muscles—In the Protremata and Telotremata these muscles have
their ventral insertion one on either side of the central axis, between the diductors. In
passing to the dorsal valve they divide mto four, and produce in that shell the two pairs of
principal scars known as the anterior and posterior centrals. By contraction these muscles
close the shell. Im the Neotremata they are the essential muscles, the anterior centrals closing
the valves, while the posterior pair serves to open the valves. In the Atremata there is a
simple pair of centrals placed near the anterior extremity of the visceral area.

Chilidium.—A dorsal plate, in appearance similar to the deltidium, covering the exterior
portion of the cardinal process in many Protremata. Its development does not begin until
early neanic or later growth, and it is probably secreted by the dorsal mantle lobe. In the
Atremata and Neotremata a similar plate, continuous with the dorsal cardinal region of the
shell, is named the pseudochilidium. (See p. 306.)

Crura.—Processes on the dorsal hinge plate of the Telotremata and some Protremata,
to which are attached the fleshy brachia and brachidia. These usually form the inner walls
of the dental sockets, and may be supported by septal plates.

Cruralium.—The dorsal equivalent of the ventral spondylium. (See p. 309.)

Delihyrium.—The triangular aperture transecting medially the ventral cardinal area, or
the posterior surface from the apex to the posterior margin of the ventral valve, through some
portion of which the pedicle passes. It has also been termed the fissure or foramen. The
delthyrium may or may not be closed either by a calcareous deltidium or a phosphatic pseudo-
deltidium. (See p. 305.)

Deltidium.—A plate more or less continuous with the cardinal margin of the ventral
valve and covering the delthyrium in Atremata, Neotremata, and Protremata. When present in
inarticulate brachiopods it is called the pseudodeltidium. In the Protremata, in which it is
always more calcareous, thicker, and more shemphy defined, it is called the deltidium or the
pseudochilidium. (See p. 305.)

Dental plates—Vertical plates supporting the teeth of the ventral valve in articulate
brachiopods. (See p. 310.)

Dental sockets Excavations in the dorsal cardinal margin of articulate brachiopods, in
which the teeth of the ventral valve articulate. The inner wall of the socket is elevated and
forms the base of the crural plate.

Diductor muscles.—In the Protremata and Telotremata the principal pair of diductor
muscles has the larger end attached to the ventral valve near the anterior edge of the visceral
area, and the other end has its insertion on the anterior portion of the cardinal process. By
contraction these muscles open the valves.

Dorsal valve-—Usually the smaller and imperforate valve and the one to which the brachia
are always attached. Brachial, hemal, socket, and entering valves are other terms more rarely
employed.

294 CAMBRIAN BRACHIOPODA.

Ephebic.—Designating the mature shell.

False area.—See Cardinal area.

Flexure line.—See Cardinal area.

Foramen.—A small circular passage through the deltidium, either below or at the apex of
the ventral valve. Sometimes the foramen encroaches by pedicle abrasion on the umbo of the
ventral valve. (See p. 314.)

Foraminal tube-—The pedicle opening through the ventral valve of neotrematous genera.
(See Pl. LVIII, fig. 5b.)

Genital markings.—Radial markings or pits within the posterior portion of the visceral
space, indicating the position and extent of the genitals.

Gerontic.—Designating old age. It is indicated in the ontogeny of many species of brachio-
pods by extreme thickness of the valves, obesity, or by numerous crowded growth lines near
the anterior margin, a condition which sometimes produces truncation and absence of striz
at the margin. (See p. 315.)

Heart-shaped cavity.—Central depressed portion of visceral area (Mickwitz). (See PI.
VII, figs. 9, 11, and 12 at x; also figs. 1, 2, and 8.)

Hinge line-—The line along which articulation takes place. Also sometimes developed
among inarticulate brachiopods.

Inarticulate brachiopods.—In the orders Atremata and Neotremata the valves do not, as
a rule, articulate by means of teeth and sockets, as is the case in the articulate orders Pro-
tremata and Telotremata.

Lateral areas.—That portion of the shell on each side of the central axis.

Listrium.—In some Neotremata a plate closing the progressive track of the pedicle opening
or pedicle cleft posterior to the apex of the ventral valve. (See p. 306.)

Longitudinal avis—A median line through the shell from the beak to the opposite margin.

Median septum.—An internal vertical plate commonly developed along the longitudmal
axis and between the muscles of the ventral valve. Sometimes there is also a dorsal median
septum. Lateral septa are rarely developed.

Middle lateral muscle scar.—See Outside and middle lateral muscles.

Neanic.—Designating youthfulness, or the stage in which specific characters begin to -

develop. :
Neotremata.—Circular or oval, more or less cone shaped, inarticulate calcareophosphatic

brachiopods with the pedicle opening restricted throughout life to the ventral valve. For a
more detailed description see ‘‘Classification of Cambrian Brachiopoda,” page 323.

Nepionic.—Designating the smooth shell stage succeeding the protegulum.

Outside and middle lateral (protractor) muscles.—In the Obolide one pair has the ventral
ends fastened at the anterior extremity of the visceral area, extending backward and inserted
near the lateral margin of the dorsal valve, outside the transmedians. A second pair originates
just behind the centrals of the ventral valve and is inserted posterior to the first pair. These
muscles draw the dorsal valve forward.

Parietal band.—The point of attachment of the muscular wall surrounding the visceral
area.
Pedicle.—The flexible muscular organ of the ventral valve by means of which brachiopods
may be attached to extraneous objects.

Pedicle furrow.—The external furrow adjoining the foramen or pedicle opening in certain
neotrematous genera. (See Pl. UXX XIII, figs. 1 and 2; Pl. LXXXIV, figs. 1 and 5c.)

Pedicle groove-—The median groove on the cardinal areas of the valves, formed by the pedicle
extending through the posterior margin of the valves when they were closed.

Pedicle muscles—In the Protremata and Telotremata one pair originates on the ventral
valve at points just outside and behind the diductors and another on the dorsal valve behind
the posterior centrals, while the opposite ends of both are attached to the pedicle. Besides these
there is an unpaired muscle lying at the base of the pedicle, attaching it closely to the ventral
valve.

ee

TERMINOLOGY. 295

Pedicle opening.—See Delthyrium.

Pedicle tube.—See Foraminal tube.

Platform.—An internal median thickening of the shell elevating the muscles. Seen in cer-
tain families of the Atremata and more rarely in the Neotremata. (See Spondylium and pp. 307
and 309.)

Pleuroceles.—Areas between the parietal band and the outer posterolateral margins.
(After King.)

Posterior region.—That portion of the shell back of the transverse axis and toward the
beak or apex.

Protegulum.—The initial shell of brachiopods. It is smooth and of microscopic size, in
outline being semicircular or arcuate and without cardinal areas.

Protractor muscles.—See Outside and middle lateral muscles.

Protremata.—Articulate calcareous brachiopods with the pedicle opening restricted to the
ventral valve throughout life or during early growth. Pedicle aperture modified by the del-

.tidium. Brachia unsupported by a calcareous skeleton but nearly always by a crura of
variable length. For a more detailed description see “‘Classification of Cambrian Brachiop-
oda,” page 325.

Pseudo-area.—See Cardinal area.

Pseudochilidium.see Chilidium.

Pseudocruralium.—Dorsal equivalent of pseudospondylium.

Pseudodeltidium.—The convex medial portion continuous with the ventral cardinal areas
in Atremata and Neotremata. (See Deltidium.)

Pseudopedicle groove.—See Pedicle groove.

Pseudospondylium.See Spondylium.

Retractor muscles.—See Anterior lateral muscles.

Septal plates —Plates supporting the crural processes, also known ascrural plates. (See p.310.)

Sessile spondylaum=Pseudospondylium.

Splanchnocele—The area within the parietal band. (After King.)

Spondylium.—aA plate in some articulate brachiopods, mainly the Pentameracea, formed
by the union of converging dental plates, to the upper surface of which are attached the adduc-
tor, diductor, and pedicle muscles. The spondylium may rest upon the ventral valve or may
be supported by a median septum. The spondylium appears to be first indicated in the artic-
ulates by a thickening of the shell of the ventral valve beneath the umbonal region so as to
form an area upon which all the muscles of the valve have their points of attachment. In
Bullingsella this is beautifully illustrated by B. exporrecta (Pl. LX XXVIIL, figs. 1d, le, and 2a) and
B. plicatella (Pl, LX X XVI, figs. 3i, 3k, and 3m). In its development the spondylium is fore-
shadowed in the Atremata by the so-called platform of Elkania (PI. LI, figs. 1 and 1a) and by the
still more primitive form in Obolus (Pl. VI). For the purpose of reference the rudimentary spon-
dylia attached directly to the inner surface of the valve, as in Billingsella, may be called pseudo-
spondylia (sessile spondyha, Ulrich), and those free or supported by a septum or septa, spondylia.
In the Atremata the homologous equivalent has been known as the platform. In Obolus,
Elkania, etc., there is sometimes developed in the dorsal valve a plate similar in appearance
to the spondylium, but different in origin; this is known as the cruralium. (See p. 307.)

Teeth.—Two processes of the ventral valve of articulate brachiopods, serving for articula-
tion. (See p. 307.)

Telotremata.—Articulate Brachiopoda with the pedicle opening shared by both valves
in nepionic and early neanic stages, usually confined to one valve in later stages, and becoming
more or less modified by deltidial plates in ephebic stages. Brachia supported by calcareous
crura, loops, or spiralia. Prodeltidium absent. (After Schuchert.)

Transmedian (rotator) muscles—In the Obolacea these are situated posteriorly just in
advance of the umbonal muscle, two on one side and one on the other. By their contraction
the dorsal valve turns alternately, first in one direction and then in the other.

Transverse axis.—A line through the shell from right to left midway between the beak
and anterior margin. (See Longitudinal axis.)

296 ‘ CAMBRIAN BRACHIOPODA.

Trapezoidal area.—The area on each side of the heart-shaped cavity in Obolus in which the
outside and middle lateral scars and central muscle scars were attached. (See Pl. VII, figs.
10 and 12.)

Umbo.—The elevated.or prominent portion of the valve anterior to the apex.

Umbonal cavity.—The hollow space in the interior of the shell beneath the umbo. -

Umbonal muscle.—A single muscle situated in the umbonal region of most Atremata. By
its contraction the valves are opened anteriorly. In Obolus this muscle divides toward the
ventral valve.

Umbonal slopes—The inclined surfaces about the umbo and opposite the cardinal slopes.

Vascular (pallial) sinuses—Two convergent or divergent primary sinuses of the circulatory
system, traversing the mantle and originating in the posterior medial region. They usually
have numerous secondary (lateral and peripheral) branches, and both often leave impressions
in the shell. (See p. 311.)

Ventral valve-—Usually the larger valve situated on ihe ventral side of the animal.

Among articulate brachiopods the dike: is usually easily distinguished by the presence of a*

delthyrium or pedicle opening through which the pedicle is protruded. In many atrematous
genera the ventral valve is not readily distinguished. When the shell is cemented to foreign
bodies it is always by the ventral valve. It is usually the larger and deeper of the two valves.
Pedicle, larger, dental, neural, and recewing valves are synonymous terms.

Visceral area.—The posterior region of the interior of the valves between the pallial sinuses;
in general the immediate area of the median muscle tracks.

Visceral cavity.—Visceral area.

THE BRACHIOPOD SHELL.
STRUCTURE.
GENERAL STATEMENT.

The general structural characters of the shell of the Ordovician and later brachiopods have
been so fully described by authors that it does not appear to be necessary or desirable to repeat
them. The student will find a full description given by Hall and Clarke im their ‘Introduction
to the study of the Brachiopoda”’ [1892a, pp. 150-225].

Some of the more important works that contain data on the structure of the shell are those
of Hancock,* King,® Carpenter,* Davidson,? and Mickwitz.¢

The greater proportion of the Cambrian brachiopods are largely corneous or chitinous.
These are restricted to the inarticulates, but the inarticulates of the Cambrian do not all pos-
sess corneous shells. Mickwitz has shown [1896, pp. 102-142] that the shells of Obolus and its
subgenera are essentially the same as those of Lingula in composition and structure. In both
the shells are composed of successive calcareous and corneous lamelle that vary in thickness
and structure. The calcareous lamelle are prismatic and crossed by minute tubules; the
corneous lamelle are compact and imperforate.

Hall and Clarke [1892a, p. 175], in speaking of the shells of the articulate brachiopods, say:

Among the articulate genera, under favorable preservation, there may be distinguished three distinct calcareous
shell layers; an inner prismatic or fibrous layer, which constitutes the greater portion of the shell; above this is a thin
lamellar layer, and the outer surface of the shell is covered by a tenuous epidermal film or periostracum. When the

shell is punctate the tubules open on the inner surface in narrow apertures, whence they widen upward, abruptly
expanding in the lamellar layer, at whose upper margin they terminate. They do not pierce the periostracum.

a Hancock, A., On the organization of the Brachiopoda, 1859, pp. 791-869.

b King, W., On some characters of Lingula anatina, 1873, pp. 1-17.

¢ Carpenter, W. B., On the intimate structure of the shells of Brachiopoda, 1853, pp. 23-45.
@ Davidson, T., On the classification of the Brachiopoda, 1853, pp. 41-136.

¢ Mickwitz, A., Ueber die Brachiopodengattung Obolus, 1896.

+

THE, BRACHIOPOD SHELL. 297

Among the calcareous, inarticulate brachiopods the shell of the Cambrian genus Obolella
shows a dense, compact, slichtly lamellated structure made up of a granular groundmass pierced
by extremely small tubules or pores. The substance of the shells of Rustella and Yorkia is
unknown, but from the character of the casts and the fact that the corneous shells of Micromatra
in the same matrix are preserved it is probable that it was calcareous. The shells of Quebecia,
Trematobolus, and Dearbornia.are also calcareous.

In Kutorgina and Schuchertina, forms that may be referred to either articulate or inarticu-
late genera, the shells appear to be calcareous, compact, and without fibrous structure.
Hall and Clarke, when speaking [1892a, p. 174] of the composition of the shell of the fossil
linguloids, say:

In the group of fossil linguloids, beginning with Lingula, passing through Lingulops and Lingulasma to Trimerella
and its allies, there is a regular increase in the relative amount of calcareous matter in the shell, so that the Trimerellas,
which are large and ponderous shells, seem to have wholly lost their corneous matter.

The predominance of corneous or calcareous shell matter does not appear to be of more
than generic importance in the classification of the brachiopods. It is true that the known
articulate genera are all calcareous, but it is equally true that among the inarticulate group calca-
reous shells occur. Alteration, replacement, and removal of original shell substance have changed
the shell of so many species that other characters must be depended on for classification.

MICROSCOPIC STRUCTURE.

Tn previous work on the Cambrian Brachiopoda, except in the cases above cited, practically
no attention was paid to the microscopic shell structure. The importance of this feature in
the classification of later species suggested the possible value of a microscopic study of the
earlier forms, and at my request Mr. KH. O. Ulrich and Mr. R. S. Bassler prepared thin sections
and also assisted in the preparation of figures 1-15 (pp. 298 and 299) and in the preliminary
study of the sections.

The preparation of thin sections of these early brachiopods is accompanied with difficulties
which, together with the lack of sufficiently extensive collections, have undoubtedly prevented
previous study along the same line. Specimens suitable for sectioning, especially of the cal-
careous forms, are not at all common, and when they do occur they are almost mvariably buried
in the rock and are so thin that the parting of the inclosing matrix does not leave sufficient
shell substance for the preparation of sections. In the present work the specific identity of a
shell was first determined by uncovering about one-half the valve, and the other half, still
embedded in the matrix, was then used in making the section. The structural features are often
restricted to individual lamelle and the right zone for microscopic examination was deter-
mined simply by close observation as grinding proceeded. Both vertical and tangential sec-
tions were prepared, the former cutting the shell at right angles and the latter cutting the shell
in planes more or less parallel to the layers or lamelle of which it is composed. The most inter-
esting results were obtained from the tangential sections, as the thin shells showed little decided
structure in vertical sections.

298 CAMBRIAN BRACHIOPODA.

Description of figures 1-15a.%

Billingsella plicatella Walcott [1905a, p. 240]:
FieurE 1.—Diagrammatic sketch of a small portion of a tangential section, X 200. The granular groundmass,
with small pores and tubules 4 or 5 times their own diameter distant from each other, is also typical of
other members of the Billingsellide. Upper Cambrian, Gallatin Valley, Montana.

Dalmanella subequata (Conrad) [1848, p. 333]:
Figure 2.—Photograph of a tangential section, X 35, showing the fibrous structure and comparatively large pores.
Ordovician, St. Paul, Minnesota. :

Kutorgina cingulata (Billings) [1861b, p. 8]:
Fieure 3.—A small portion of the tangential section shown in fig. 8, X 200. The minute structure of this and
the following species is essentially the same as that shown in fig. 5, the only difference being the closer
arrangement of the pores. Lower Cambrian, Swanton, Vermont.

Obolus apollinis Eichwald [1829, p. 274]:
FicureE 4.—Small portion of tangential section, < 200. The minutely porous granular structure is beautifully
shown in this species, in which the pores are arranged more closely than in any other observed. Upper
Cambrian, Obolus sandstone, Hsthonia, Russia.

Billingsella coloradoensts (Shumard) [1860, p. 627]: .
Figure 5.—Photograph of horizontal thin section enlarged fifty diameters. This shows the characteristic eranular
groundmass of the Cambrian Billingsellide. Upper Cambrian, Morgan Creek, Burnet County, Texas.

Nisusia festinata (Billings) [1861b, p. 10]:
Ficure 6.—Photograph of horizontal thin section enlarged fifty diameters. This section shows a granular ground-
massin which faint indications of small pores or tubules may be seen with a high power. Lower Cambrian,
2 miles east of Swanton, Vermont.

Loorthis remnicha (N. H. Winchell) [1886, p. 317]:
Fiaure 7.—Photograph of horizontal thin section enlarged fifty diameters. This section shows the same type of
groundmass as that illustrated by fig. 6. Upper Cambrian, Cold Creek Canyon, Burnet County, Texas.

Kutorgina cingulata (Billings) [1861b, p. 8]:
Ficure 8.—Photograph of horizontal thin section showing granular shell substance. There are few slight indi-
cations of pores. Lower Cambrian, Swanton, Vermont.

Dalmanella multisecta (Meek) [1873, p. 112]:
Ficure 9.—Horizontal thin section enlarged fifty diameters. This shows the fibrous structure of the shell pene-
trated by numerous fine tubules. Ordovician, Eden shale, Cincinnati, Ohio.

Dalmanella parva (de Verneuil) [1845, p. 188]:
Fieur£ 10.—Horizontal thin section showing fibrous structure; alge, section of the tubules that penetrate through
the shell. Middle Ordovician of Russia.

Syntrophia lateralis (Whitfield) [1886, p. 303]:
Ficure 11.—Horizontal thin section enlarged fifty diameters, showing the arrangement of the pores in lines that
radiate from the apex toward the margin. Lower Orddvician, Beekmantown, Fort Cassin, Vermont.

Plectorthis plicatella (Hall) [1847, p. 122]:
Ficure 12.—Horizontal thin section enlarged fifty diameters. This section shows the fibrous structure so
characteristic of the Ordovician orthoids. Ordovician ‘‘Lorraine shaly limestone,’’ Cincinnati, Ohio.

Huenella abnormis (Walcott) [1905, p. 289]:
FicuReE 13.—Horizontal thin section enlarged fifty diameters. The pores in this genus are smaller than in
Syntrophia, but their arrangement is essentially the same and shows the line effect characteristic of the
Pentameracea. Upper Cambrian, Gallatin Valley, Montana.

Obolella crassa (Hall) [1847, p. 290):
Figure 14.—Horizontal thin section enlarged fifty diameters. This shows.the fine granular groundmass, with an
indication in the upper left side of the section that a surface ornamentation has been cut across. Lower
Cambrian, Bic, Canada.
Obolus apollinis Eichwald [1829, p. 274]:
Figures 15 and 15a.—Transverse vertical thin sections enlarged so as to show the lamelle and the presence of a

large tubule that appears to have more or less imperfectly penetrated through the shell. Upper
Cambrian, Obolus sandstone, Russia.

a Figs. 1-4 are copied from figs. 2-5 on p. 151 of a preliminary paper on the classification of the Cambrian Brachiopoda [Walcott, 1908e]. igs.
5-15 and 15a are copied from figs. 1-12, Pl. XII, of the same paper.

THE BRACHIOPOD SHELL. 299

300 CAMBRIAN BRACHIOPODA.

The general resemblance of the Cambrian eoorthoids to certain Ordovician Protremata is
so striking and the lines of descent so suggestive that particular attention was devoted to this
group. Examination, however, brought out the fact that this apparent relationship disappears
when the shell structure of the two groups is compared.

Sections of the shells of members of the Billingsellide, of which figure 1 is typical, all show
a lamellar structure with mdications of more or less numerous, scattered, very minute pores or
tubules passing without interruption through one lamella. In some sections the spots indicating
the tubules are arranged in rows radiating from the beak of the shell to the margins, but no other
regular arrangement can be seen. The great mass of the shell is made up of a compact, finely
granular base with dark spots and occasional minute crystals of calcite, a groundmass which,
under the microscope, appears very much like that of a fine argillaceous shale.

The Ordovician Protremata have a clearer, more crystalline aspect or color than the Cam-
brian Billingsellide, a difference which probably indicates either a purer lime composition for
the former or more probably a higher percentage of calcium phosphate for the latter. In
chemical aspect the shells of the Billingsellide appear to resemble those of the Atremata and
Neotremata more closely than do the Orthide. (Compare figs. 1, 3, and 4 with 2.)

Analyses of the respective shells would be necessary to prove hase relations, but they are
interesting subjects for investigation in view of the possible derivation of the Billingsellidz from
the Atremata.

In the Cambrian articulate genera, with the possible exception of Syntrophia and Huenella,
the minute, fibrous structure so characteristic of most if not all orthoids is entirely absent.
(Compare figs. 1 and 2.) Syntrophia and Huenella, however, greatly resemble each other.
Thus sections of the shell of Huenella abnormis of the Upper Cambrian (fig. 13) and Syntrophia

lateralis of the Lower Ordovician (fig. 11) show the same radial arrangement of the pores seen ~

in the Billingsellidz, but the shell structure is fibrous and the rows are coincident in direction
with the fibers. On closer study this apparently fibrous structure can be resolved into more or
less parallel bands or walls of shell substance separating rows of closely arranged, rectangular,
porelike spaces. These spaces may be seen distinctly in thick sections, but they Agama when
the section is made sufficiently thin to give a clear image under very high power. Sections of
the linguloid genera were also prepared and studied, but the thinness ‘ad the shells and their
sihagsineiive character prevented very satisfactory results. The irregular large tubules men-
tioned by Mickwitz [1896, p. 106] are beautifully shown in sections of Caine apollinis before me.

Some of the tubules penetrate several lamellz of the shell and suggest the tubules of some
of the orthoids. (See figs. 15 and 15a.) The same general structure, with the exception of
the larger tubules, appears to be characteristic of all of the corneous shells of the Atremata and
Neotremata, and, so far as known to me, of all of the Cambrian corneous shells.

Figures 5-14 are from photographs which have not been retouched, so that personal equa-
tion may be eliminated. Unfortunately, higher magnifications could not Ne used without a loss of
clearness, but even at the present magnification these views show decided differences in structure.

In conclusion, it appears that the Cambrian Billingsellide are further removed from the
Ordovician and later Protremata than has hitherto been suspected, the microscopic shell struc-
ture in the former being of granular material pierced by small pores and in the latter of fibrous
material. On the other hand, the microscopic structure of the Cambrian and later Pentameracea
is so similar that an unbroken line of descent 1s indicated.

SURFACE ORNAMENTATION.
GENERAL STATEMENT.

The known protegulum of all brachiopods is smooth, and the shells have usually advanced
well into the nepionic stage of growth before the outer surface is ornamented to any considerable
degree. Many species of Chmaiaienn inarticulate brachiopods (especially the Obolacea) remain
smooth through all stages of growth, with the exception of lines and varices of growth. Many of
them, however, have some bona of ornamentation, and some of the most ornate types of surface,

THE BRACHIOPOD SHELL. 301

such as that of Micromitra ([phidella) pannula (Pl. IV) and Botsfordia cxlata (Pl. LIX), were
fully developed in Lower Cambrian time.

I have given much attention to the question of the value of surface ornamentation for the
purposes of systematic classification among the Cambrian brachiopods, and have concluded
that only in cases where a distinctive surface is persistent for a considerable period can it be
considered of more than specific value. In one instance I have given the type of surface found
on Obolus (Westonia) aurora (Pl. XLVI, fig. 1h) a subgeneric value, but its wide range of varia-
tion makes me doubtful of its utility.

ATREMATA.

So far as known, the outer surface of Rustella, the most primitive type of brachiopod known
(Pi. I, figs. 1, la—e), is marked only by concentric growth lines. Among other genera referred to
the Paterinide, Volborthia (Pl. I, figs. 6, 6a-e) has only concentric growth lines on the outer
surface, although it has numerous radiating lines on the inner laminations of the shell. On
the outer surface in the genera Mickwiizia (Pl. VI) and Helmersenia (Pl. LXIII, figs. 7, 7a, and
7e) are found concentric and radiating lines and small tubercles (apparently rudimentary
spines) that are ornamental in their arrangement and effect, but it is in Micromitra that the
greatest variety and most highly ornamented surfaces appear. Species that have a simple type
of surface, marked only by concentric lines of growth, are grouped under the subgenus Paterina
(Pl. II), while those having an ornate surface (Pl. IV) are included in the subgenus Jphidella.
Transition forms, intermediate in surface ornamentation between the two extreme types, are
referred to Micromitra, since the type species, M. sculptilis, has this termediate form of
surface. The species Micromitra (Paterina) pealei (P1. III, figs. 3, 3a-e) approaches closely to
Micromitra sculptilis (P1. 11, figs. 5, 5a, and 5e) but is not quite so highly ornamented. Micro-
mitra (Iphidella) pannula and its varieties (Pl. TV) have a highly ornate surface, and the species
has both wide geographic distribution and stratigraphic range. It is abundant in the Middle
Cambrian and it also occurs in the upper portion of the Lower Cambrian section in Nevada.
The oldest known brachiopod from British Columbia, Micromitra ([phidella) lowise, which
occurs 3,090 feet down in the Lower Cambrian terrane, has an orndmented surface much like
that of M. (.) nyssa (Pl. III, fig. 9), which occurs at the summit of the Lower Cambrian in the
same stratigraphic section.

None of the Obolidz of the Lower Cambrian is known to have an ornamented surface, but
in the Middle Cambrian many species show, in addition to the concentric striz and lines of
growth and the radiating strie and ridges, a variously pitted and granulated surface primarily
formed by the crossing of the radiating and concentric ridges by oblique undulating ridges.

What I have called the Westonia type of surface (Pls. XLVI and XLVII) is the most
common. A variety of this type where the lines are transverse is more rarely seen (Pl. XLIX,
fig. 1fand 1g). The Westonia surface is not confined to Obolus (Westonia), as it occurs among the
Neotremata in the genera Obolella (Glyptias), Botsfordia, Acrothele, Acrotreta, and Acrothyra.
(See description of Obolus (Westonia), p. 450.) It is also present on Ordovician and later brachio-
pods and it is known on Lucinia divaricator and other pelecypods. [See Winchell and Schuchert,
1895, pp. 345-346.]

In Obolus (Acritis) (Pl. XIII, fig. 3) the irregular, undulating, and more or less inosculating
concentric ridges suggest one of the rudimentary characters of some types of the Westonia surface,
but their origin was probably different. The surface of Lingula cincta Barrande [1879b, Pl. CV,
figs. 1A, 2A, and 2f], from Etage E (Ordovician), is much like that of Obolus (Acritis) anti-
quissimus, but it is probably an illustration of the persistence of a form of surface sculpture
through several geologic formations and a corresponding period of time.

The surface of Lingula eximia Barrande [1879b, Pl. CV, block 1] is highly ornate. The
figure is introduced on Plate XXXII, fig. 3, as a possible type that may be found to have existed
in late Cambrian time. Obolus (Mickwitzella) siluricus (Pl. XV, figs. 1b and 1c) has fine crenula-
tions on the front side of certain concentric ridges, a type of ornamentation that is unknown
among the Cambrian brachiopods except in this one Upper Cambrian species.

302 CAMBRIAN BRACHIOPODA.

The presence of spines in inarticulate genera is of rare occurrence. The oldest known
indication of their presence in other families than the Paterinide is on Bicia gemma (PI. L, fig. 1a)
and Nisusia festinata (Pl. C, fig. 1) of the Lower Cambrian. The Middle Cambrian Misusia

alberta (P1. C, fig. 3c) has a series of strong spines, and, in the Upper Cambrian, Acrotreta spinosa |

(Pl. LXXIX, figs. 4a, 4b, and 4g), Schizambon (Pl. LX XXIV, figs. 1d and 3a), and Helmersenia
ladogensis (Pl. LXIII, fig. 7e) appear to have had a spimose surface.

NEOTREMATA.

Obolella (Pls. LIV and LY) has, so far as known to me, only concentric lines and ridges of
growth, but the surface of Botsfordia is usually quite ornate. The granular type is best shown
by B. granulata (Pl. LVII, fig. 4r) and B. celata (Pl. LIX, figs. 1h and 1o), and the pitted or
reticulated type, formed by the crossing of obliquely concentric ridges, by B. pulchra (Pl. LXII,
figs. 5, 5a-f, and 5k). Botsfordia? barrandei (Pl. LYVII, figs. 7, 7a, and 7b) appears to have
a smooth surface or one marked only by concentric growth lines.

Trematobolus of the Siphonotretide is like Obolella in having a plain surface, but in Y orkia
orientalis (Pl. LX XXII, fig. 3a) the surface is of the reticulated type and resembles that of
Micromitra ([phidella) pannula of the Atremata. Siphonotreta has a finely granulated surface
(Pl. LXXXI, figs. 6 and 6a), also a pustulose surface (Pl. LX XXI, figs. 5 and 5a). The latter
type is found in the Atremata in Mickwitzia (Pl. VI, fig. 2) and the granulated surface is present
in Botsfordia (Pl. LVII, fig. 4r) of the Obolellide. The surface of Schizambon (Pl. LX XXIV,
figs. 1d and 3a) differs from all other genera of the Neotremata excent Acrotreta (Pl. LX XIX.
fig. 4¢) in being spinose.

The surface of Acrothele varies in almost the same manner as that of Micromitra. Species
occur with only concentric growth lines, as in Acrothele subsidua (Pl. LX, figs. 1c, 1d, and 11),
or the same species may have a few radiating ridges (Pl. LX, figs. 1a, 1b, and 8). The radiating
ridges may be characteristic of some forms of the adult shells of the species, as in A. matthewi
multicostata (Pl. LXI, figs. 5, 5a—c). In addition to these, there may be an irregular more or less

inosculating series of fine concentric ridges, as in A. avia (Pl. LXII, fig. 1}); a finely granular |

surface, asin A. coriacea (Pl. LVI, fig. 1g); a more distinctly and strongly granular surface, as in
A. (Redlichella) granulata (Pl. LVI, fig. 2g) or A. prima costata (Pl. LXI, fig. 4d). A pitted
surface is sometimes formed by the crossing of obliquely concentric narrow ridges, asin A. bella-
punctata (Pl. LVI, fig. 3b).

Only a few species of Acrotreta have more than the smooth surface with concentric lines.
I was greatly surprised when I found a shell showing a spinose surface, A. spinosa (Pl. LX XIX,
figs. 4a, 4b, and 4¢), and again when I found a reticulated surface, A.? cancellata (Pl. LX XIX,
fig. 5a). Both species are from the fauna of the Cordilleran sea; A. spinosa developed in late
Cambrian time and A.? cancellata in early Ordovician time. The closely related genus
Acrothyra has a very fine Westonia type of surface (Pl. XLVII) that can be seen only with the

aid of a strong lens.
PROTREMATA.

The ornamentation of the surface of the shells of Protremata is usually in the form of
radiating striz, lines, and ridges of varying size and number, with concentric lines and ridges
of growth. The radiating strie, lines, and incipient ridges or plications are usually first seen on
the inner laminations of the shell, and often this occurs in species that do not show it on the
outer surface of the shell. This is beautifully shown in the atrematous genera Mickwitzia
(Pl. VI, figs. 1k and 1 1), Obolus (Pl. VIII, figs. 1i and 2; Pl. X, figs. 2 and 2e), Obolus (Westonta)
(Pl. XII, figs. 7 and 7c; Pl. XLVII, figs. 1a, 1g, and 1m), Obolus (Lingulobolus) (Pl. XVI, figs. 1,
1b, 2c, 2f, 2h, and 2i), Lingulella (Pl. XVII, fig.11; Pl. XX XT, figs. 6e and 6g; Pl. XX XVIII,
figs. 2d and 2f), Lingulella (Lingulepis) (Pl. XLI, figs. 1a-c, 1f-h, and 1j—m), and Dicellomus
(Pl. LIT, figs. 2c and 2h; Pl. LIII, figs. 1b, 1c, 2, 2a, 4a, 4d, and 4e). In Bicia gemma (PI. L) the
radiating lines and ridges occur on both the interior and exterior surfaces, and there are also
elongated tubercles that suggest fine spines. In Kutorgina granulata (Pl. V, figs. 5b and 5c)

pee Ten ee EEE aoe

THE BRACHIOPOD SHELL. 303

they are strong on the inner surface and less marked on the outer surface. Other species of
Kutorgina (Pl. V) have a smooth, or only concentrically lined, surface. Schuchertina cambria
(Pl. LI, figs. 6, 6a—m) has a fine series of internal radiating strie and ridges, but the exterior
surface is without them.

Among the Protremata the radiating ridges are present in most genera, although some
species of a genus may not have them. In the Billingsellmz a few species with smooth shells
occur (Pl. LX XXVII, figs. 1, la-e, 7, 7a, 5, and 5a), but the greater number have both interior
and exterior radiating ridges (Pls. LXXXVII-XC). Among the Nisusiine and EKoorthine
all the species show more or less of external radiating lines and ridges; sometimes the young
shells are nearly smooth (Pl. XCVIII, figs. 1f, 2b, and 5), but this in most cases is at a very
young stage of growth. The Syntrophiide show variation from the smooth adult shells of
Syntrophia caicifera (Pl. CIV, figs. 1, la) to the strongly costate shells of Huenella texana
(Pl. CII, fig. le). Swantonia (Pl. CIV, figs. 5 and 6) has numerous radiating coste.

INTERLOCKING PLICATIONS.

Interlocking of the margins of the valves began as soon as plications or ribs first appeared
on the shell. The wide variation in size and number in the same species (Pl. CIII, figs. 1, la-c)
indicates that this character is, like that of surface ornamentation, of little more than specific
value. In the description of the surface ornamentation of the Protremata (p. 302) reference
is made to the order of appearance and the character of the ridges or plications among the
Cambrian brachiopods.

CARDINAL AREA.

ATREMATA.

In the protegulum stage of the atrematous shells the posterior margins of the valve are
not bent regularly inward toward each other and there are no indications on the surface of a
cardinal area. There is a simple cleft, the length of which is dependent on the degree of round-
ing of the posterior margins. Among the genera and species referred to the order Atremata,
the pseudodeltidium of Rustella edsoni (Pl. I, figs. 1b, 1c, le) is extremely rudimentary, if devel-
oped at all, and there is no trace of a thickened cardinal surface. The pedicle appears to have
impressed itself on the shell to the extent of making a shallow furrow on the posterior inner
margin of the rather thick shell of the two valves. In Mickwitzia monilifera (PI. VI, fig. 1’’)
the pressure and movement of the pedicle against the vertical cardinal margin during the
growth of the shell have had the effect of bulging it outward so as to produce a pseudodeltid-
ium, but on neither of the valves is there a trace of a cardinal thickening. In Helmersenia lado-
gensis (Pl. LXIII, fig. 7d) a pseudodeltidium similar to that in Mickwitzia occurs on the ventral
valve, and here also there is only a thickening of the posterior margin and not a true cardinal
area. In the genus Micromitra the mechanical influence of the pressure of the pedicle on the
ventral valve is much more pronounced; in Micromitra (Paterina) bella (P1. II, figs. 1a and 1b) the
pseudodeltidium is more clearly defined than in Mickwitzia or Helmersenia, and the concave
arch of the cardinal margin for the protrusion of the pedicle is greater. In Micromitra (Paterina)
superba (PI. II, fig. 7) the excavation of the pseudodeltidium has increased, and in Micromitra
(Paterina) logana (Pl. I, fig. 6b) and Micromitra (Iphidella) pannula (Pl. IV, figs. 1d, 2a’’,
and 2b’) the pseudodeltidium has been excavated to such an extent that there is nearly an
open delthyrium. This difference in delthyrial openings must be due to variation in the thickness
of the pedicle. Attention is called to the pseudodeltidium shown in figure 2a’’, Plate IV, where
the tripartite, longitudinal division recalls the pseudodeltidium of Acrotreta nicholsoni (PI.
LXXIII, figs. lg and 1h). So far as known to me, no true cardinal area is present in any species
of the Paterinidz, though there may be a more or less marked thickening or bulging of the
posterior margin of the valves to form a pseudodeltidium.

In the Obolidz the vertical cardinal area is present in all known species, but in varying
degree of development. It is slightly shown in Delgadella (Pl. X XIX, figs. 5, 5a, and 5b) and
well defined in Obolus prindler (Pl. X XVII, figs. 3a, 3b, 3c, and 3e), Lingulella granvillensis

304 CAMBRIAN BRACHIOPODA.

(Pl. XXII, figs. 1 and 1b), Lingulella nathorsti (Pl. XXXI, figs. 1 and 1a), and Langulella schu-
cherti (Pl. XXI, fig. 6), all of which are from the Lower Cambrian. Lingulella schucherti is
probably the oldest known. species, unless it be Delgadella lusitanica. In Dicellomus the cardinal
area of the ventral valve (Pl. LII, figs. 1e and 1d) is not unlike that of Obolus, except that short,
teeth (Pl. LII, fig. 1d) appear to have been developed, and that on the cardinal area of the
dorsal valve (Pl. LII, fig. 1i) there is a socket-like groove on each side for the reception of the
projection in the ventral valve. On other specimens of the area of the dorsal valve there
are many minor depressions or crenulations (Pl. LII, fig. 1j), but no defined groove or socket.
On the dorsal valve of another species the cardinal area (Pl. LIII, fig. 1) is not unlike that of
the dorsal valve of Obolus. There is considerable variation in the details of form and size of the
vertical cardinal areas of the various species of Obolus, its subgenera, and Lingulella, but it is
all within the typical Obolus-like cardinal area as seen in Obolus apollanis (Pl. VII). A curious
individual development. or extension of the area is shown in some specimens of Obolus namouna
(Pl. VIII, fig. 2a) and O. rhea (Pl. IX, fig. 1), where the posterior margin of the mantle appears
to have been drawn farther forward inwardly and a thin deposit of shell made, so as to carry
the front margin of the cardinal area far in advance of its usual position in the species of the
genus. On.Bicia; one of the oldest genera (Pl. L), the area is as strongly defined as it is in
Obolus and. its subgenera, and teeth or articulate processes are suggested. In Elkania (Pl. LI,
figs. 1 and 1a)-the cardinal area so merges into the thickened platform that it is not readily
sepomnile from it., I have referred to this as the internal cardinal area, or the area that is
inclined inward from the plane of the margins of the valves and united by shell deposit to the
interior of the shell. In Neobolus the internal cardinal area of the dorsal valve extends forward
as a semicircular shelf (PI. I, fig. 4b). It is a modified cardinal area on the plane of the maxgins
of the valves, but in the aaalt it does not extend over the rounded posterior margin of the valve.
The area of the ventral valve is unknown, but from the presence of an open delthyrium (PI. I,
fio. 4’) it is not probable that a srellnalesfined cardinal area exists.

In the dorsal valve of Lingulella granvillensis (Pl. XXII, fig. 1d), Lingulella helena (Pl. XXIV,
fig. 3c), Obolus (Westonia) euglyphus (Pl. XLVIII, fig. le) there is a strong undercut or opening
beneath the area adjoining the pedicle furrow. This also occurs in the ventral valve of the

last-mentioned species (Pl. XLVIII, figs. 1c and 1d) and in many species of Obolus and its sub- _

genera and in Lingulella. In other species the area may be thickened so as practically to
lowe up the space between it and the inside of the valve (Pl. VII).

In Kutorgina (Pl. V) the cardinal areas are in a very rudimentary condition, and com-
parable with the rudimentary cardinal areas of Micromitra (Pls. II, III, and IV). The general
form and structure of Autorgina, taken in- connection with the rudimentary cardinal areas
beneath the beaks of the valve, give the areas a significance that those of Micromitra do not
possess. It is highly probable that a number of intermediate forms, in which the cardinal
areas gradually obtained their more mature character, were developed between the type from
which Kutorgina was derived and Nisusia and Billingsella, but nothing is known of such inter-
mediate forms in the Lower Cambrian. Schuchertina (Pl. LI, figs. 6, 6a—m) appears to have
been descendant from some atrematous type that may also have been the ancestral stock of
Kutorgina and the forms that passed into Nisusia and Billingsella. Schuwchertina is a primitive
protrematous genus still preserving strong atrematous characters—or vice versa, according to
one’s point of view.

NEOTREMATA.

The cardinal areas of the valves of Obolella (Pls. LIV and LY) of the Lower Cambrian are
essentially the same in appearance as those of Obolus, except that they are not usually so strongly
developed. They may also be compared with the cardinal areas of Bicia (Pl. L), especially
the projections on the inner angle adjoining the pedicle furrow. The narrow, thickened cardi-
nal margin in the ventral valve of Obolella does not clearly show from the interior view, although
such specimens as that illustrated on Plate LIV, figure 2h, indicate that the area is not so promi-
nent as in the ancestral form. This is more clearly shown on Plate LIV, figure 2g. In

THE BRACHIOPOD SHELL. 305

Botsfordia celata (Pl. LIX, figs. le, 1f, and 1k) the cardinal areas are present but subordinate
as compared with the areas of Obolella. They are still less in evidence in Botsfordia granulata
(Pl. LVII, figs. 4g—m) and Botsfordia pulchra (Pl. LXU, figs. 5g-j). In Neobolus (Pl. LXXXI,
figs. 2e-h) the reduction of the cardinal areas has progressed until they are no longer a marked
feature of either valve. In Trematobolus (Pl. LX XXIII and Pl. LXXXIV, figs. 5a and 5b) the
development, of the pedicle tube is much more advanced than in Obolella, but the cardinal areas
are here again a prominent feature; they are less clearly defined in Yorkia (Pl. LX XXII,
figs. leh), in which the pseudodeltidium of the ventral valve is developed (Pl. LXXXII,
figs. 1b-c). In other forms of the Siphonotretide the cardinal areas as developed in the
Obolidz are not seen in the adult stages of growth.

It is interesting to note that the vertical thickened cardinal area is present in the oldest
known brachiopod, Trematobolus excelsis (Pl. LX XXII, fig. 8), which occurs stratigraphically
lower down in the Lower Cambrian of North America than any other species of brachiopod
known tome. Linnarssonella, with its low false area and strongly marked interior of its valves,
has also a well-defined cardinal area in some species (L. modesta, Pl. LX XVIII, fic. Se;
L. girtyi, Pl. LXXIX, figs. 11, Im, and Ir), in this feature suggesting that it is more primitive
than either Acrotreta or Acrothele. Quebecia is a very ancient form, but so far as known it
passed in the adult beyond the stage of having a vertical cardinal area. Nothing is known
of the interior of Discinolepis of the Middle Cambrian, but in the dorsal valve of Keyserlingia
the thickened cardinal area is a well-developed feature (Pl. LXXXI, fig. 4e). Acrotreta occa-
sionally shows a vertical cardinal area in the dorsal valve (A. definita, Pl. LXIV, fig. 2d; A.
kutorgar, Pl. LXV, figs. 3h-]; A. curvata, Pl. LXVIIL, figs. 1k and 11; A. ophirensis, Pl. LXXIV,
fig. 1f; A. ophirensis descendens, Pl. UXXVIII, fig. 1e; and A. marjumensis, Pl. LUX XVIII,
fig. 2c). Other examples doubtless occur, but it appears that in both Acrotreta and Acrothyra
the vertical cardinal areas are absent or so reduced as no longer to be a generic character; the
same is to an even greater degree true of Acrothele. Acrothele bellula (Pl. LVIIL, figs. 5e—h) has a
defined cardinal area in the dorsal valve and a trace of one on the ventral valve; otherwise,
only the false external area back of the pedicle opening is known to me among the species of
Acrothele, its subgenus Redlichella, or Schizopholis. Nothing is known of a thickened vertical
cardinal area in Orbiculoidea or Philhedra.

PROTREMATA.

Two of the earliest forms of the Protremata (Billingsella (Pl. LXXXYV) and Nisusia (Pl. C))
both have a clearly defined cardinal area on the ventral valve, divided by a delthyrium that is
more or less completely covered by a deltidium. These characters appear to be developed in
the same manner as in the Inarticulata; im other words, they are the result of holoperipheral
growth and pedicle pressure bulging the median region of the cardinal area. No deltidial
plates are known in the Billingsellide. So far as known Otusia has an open delthyrium. The
cardinal area of Wynnia (Pl. LXXXIX, fig. 4b) has a large, open delthyrium, with no trace
of a deltidium in any of the four specimens from India. The figure shows a bit of shell at the
top of the delthyrium, but thisisnotin place. The identification of the subfamily Rafinesquinz
by Eostrophemena is of doubtful value (Pl. XCV, figs. 6, 6a—b) and nothing is known of the
area of the ventral valve. Hoorthis (Pl. XCI),. Orusia (Pl. XCVIII), and F inkelnburgia
(Pl. XCIIT) have an open delthyrium in the ventral valve. The cardinal area of Swantonia
(PI. CIV, figs. 5 and 6)is unknown. MHuenella has a clearly defined area on both valves and an
open delthyrium (PI. CIII, figs. 1c, 2g, 21, and 3’’).

DELTHYRIUM AND DELTIDIUM.

The development of the delthyrium from the simple Rustella stage, where it is scarcely
more than a broad opening between the valves, to the definite form in the higher types of the
Protremata, where it is either open or more or less closed by a deltidium, has been outlined in

62667°—vot 51, pt 1—12——20

306 CAMBRIAN BRACHIOPODA.

connection with the notes on the cardinal areas. The evolution in the Atremata, Neotremata,
and Protremata has been in the same direction, ranging from the open-fissured protegulum
stage in pre-Cambrian time to the fully developed, clearly defined, subtriangular, usually
convex pseudodelthyrium and deltidium. In Acrotreta kutorgai the cardinal area and deltid-
ium of the dorsal valve are well defined (Pl. LXV, figs. 31 and 3j). I amr inclined to think
that the pseudodeltidia of the Atremata and Neotremata, as also the deltidia of the Protre-
mata of the Cambrian, are all the result of holoperipheral growth and not of growth from a
prodeltidial plate, as interpreted by Beecher [1892, p. 142].

The deltidia of the Protremata vary in size hom the large deltidium of Billingsella colora-
doensis (Pl. LXXXV, figs. In and 1o) to those in which the delthyrium is entirely open in the
mature stages of the andirvicthell, The exact stage at which the rudimentary deltidia resulting
from the holoperipheral growth of the shell begin to take on the more definite form shown in
Nisusia (Pl. C) and Billingsella (Pl. LX X XY) is unknown.

From my studies of the Cambrian brachiopods I see nothing that leads me to the belief
that in the Protremata the deltidium has a different origin from the pseudodeltidium of the
Atremata. Whatever the significance of the prodeltidium or third shell plate of the Neotremata
may be, it is plain from the many species of Atremata, Neotremata, and Protremata through-
out the Cambrian that the pedicle openings tend to develop in two directions; resulting, Anst,
in a more or less large open delthyrium, due in all probability to a thick and short rac tnmaellé
filling up the space, and, second, in a more or less covered delthyrium (the covering being
either the phosphatic pseudodeltidium or the calcareous deltidium), the peduncular opening
being either between the two valves or reduced to a foramen limited to the ventral valve.

LISTRIUM.

Hall and Clarke [1892a, p. 153] déemed it important to apply the term listrium to the
caleareous deposition or plate closing the progressive track of the pedicle opening or pedicle
cleft. posterior to the apex of the reat valve. This feature is known only in Orbiculoidea
among Cambrian genera of Brachiopoda. It has not been observed in the Siphonotretide.

PSEUDOCHILIDIUM.

The pseudochilidium is a convex plate closing the primitive aperture in the dorsal valve
of Atremata and Protremata. It corresponds to the pseudodeltidium of the ventral valve and
is formed about the dorsal side of the pedicle aperture.

CARDINAL PROCESS.

The cardinal process, like the crura, was evidently developed in the interval of progression
represented between the progenitor of Kutorgina and Billingsella. ‘The process is unknown
in Kutorgina, but is very clearly developed in the Middle Cambrian forms of Billingsella
(Pl. LXXXV, figs. lu-y; Pl. LX XXVI, figs. 3] and 3n; and Pl. LXX XVIII, figs. 1f and 11).
I have not ahead it in Nisusia or ines (Jamesella) of the Lower and Middle Cambrian.
It appears in Hoorthis remnicha (Pl. XCI, figs. 1q and Ir; Pl. XCII, fig. 2b) of the Middle Cam-
brian, but I have not seen it distinctly in the Ordovician Protorthis (Pl. XCIX). ;

The development of the process followed the definite cardinal area and hinge teeth and
must at first have been quite rudimentary. Its absence in Misusia and its presence in Billings-
ella indicate that the latter is a more progressive type in this respect. In the Middle Ordo-
yvician orthoid Dinorthis subquadrata the cardinal process is striated and fluted so as to give a
better holding surface for the attachment of the muscles. In the Silurian genera Waldheimia
and QOliothyris the entire concave part of the area of the dorsal valve projects as a plate poste-
riorly beyond the beak.

The cardinal process becomes more specialized in its bifurcated condition in the Stropho-
menidz and Productide, etc. (See Hall and Clarke [1892a, p. 168] for further description of
this process. )

THE BRACHIOPOD SHELL. 307
ARTICULATING PROCESSES.

Among the Atremata, Bicia of the Lower Cambrian shows strong projections on the anterior
portion of the cardinal area of the ventral valve beside the delthyrium (Pl. L, figs. 1i-k and
2a), but no corresponding sockets or means of articulation in the dorsal valve. It is a matter
of interest to note that bosses occur on both valves (Pl. L, figs. 2, 2a-e) close to the front mar-
gin of the cardinal area, which were evidently of service in connection with the movement of
the valves. In Dicellomus the area of the dorsal valve is sometimes grooved in such a manner
(Pl. LIL, fig. 11) as to suggest an articulation with a projection on the ventral valve, and the
crenulated margin of figure 1] is suggestive of another tendency toward developing articulation
of the valves.

The actual presence or absence of articulating processes in Kutorgina cingulata (Pl. V) is
very difficult to demonstrate by observation, owing to the character of the matrix in which the
specimens occur. That some form of articulating processes 1s present, however, is indicated
by the facts (1) that m a relatively small collection thirty of the valves are united, and (2) that
in only a few instances is the dorsal valve in any other than the normal position in which it
would have been held by teeth in the ventral valve. In only a few of the specimens have the
valves slid or turned either way, as they usually do in the inarticulates.

In the Neotremata, the Lower Cambrian Obolella (Pl. LV, figs. 1e-¢) has projections suggest-
ing an articulating process on either side of the delthyrium. The same is true of Trematobolus
(Pls. LX XXIII and LXXXIYV).

In the Protremata the articulating processes are well developed in Billingsella (Pl. LXXXV,
figs. In, 1v, and 1w), and, so far as known, in Miswsta and the other genera of the order.

SPONDYLIUM.

I am inclined to agree with Doctor Schuchert that the spondylium originated as the result
of deposition, within the ventral rostral cavity, of testaceous matter about the bases of the
adductor, diductor, and pedicle muscles [Schuchert, 1897, pp. 100-102]. With this conception
in mind we may consider that the shg¢htly demarked rostral muscular area of Misusia is one of
the earliest known traces of pseudospondylia, and that it is followed by the more decidedly
elevated muscular area or pseudospondylium of Billingsella, which is of the same type as that of
Clitambonites and essentially of the same general type as that of Hoorthis. In Filkelnburgia the
pseudospondyhum appears to have been supported at its anterior margin by three septa (PI.
XCIUII, fig. 2), thus forming a link between the pseudospondylium of Billingsella and the spon-
dylium of Syntrophia. In Hueneila (P1. CII, figs. 1h, li, 21, and 2m) the spondylium is free
at the sides and without a supporting septum (as in Syntrophia, Pl. CII, fig. 6g; Pl. CII,
figs. 4d and 4e) or septa (as in Clarkella, Pl. CIV, figs. 2c and 2d).

Protorthis has no well-observed cardinal process in the dorsal valve, although it has gained
a true spondylium in the ventral; and Syntrophia gains a cruralium in the dorsal valve, both
valves of Syntrophia rotundata having either a spondylium or cruralium supported on a median
septum (PI. CIII, figs. 4d and 4e). In Clarkella the spondylium is supported by three or more
septa (Pl. CIV, figs. 2c and 2d).

In chronologic order the pseudospondylium of the ventral valve first appears in the Lower
Cambrian Billingsella highlandensis (Pl. LX X XVII, fig. 4b) and B. orientalis (Pl. LXXXVI,
fig. 2). It is present in all species of Billingsella from the Middle and Upper Cambrian, and
has the same form in the Middle Cambrian as in species of Hoorthis of the Middle and Upper
Cambrian. On this line of descent the pseudospondylium appears in Orthis (see Hall and
_ Clarke [1892c, pp. 186-194]) of the Ordovician and later faunas, probably as a reversion from
a free spondylium. On the line of descent to Protorthis the pseudospondylium becomes a free
spondylium and continues on through Syntrophia and Clarkella into the Ordovician and Silurian
Pentameride and Clitambonitide. ;

It is not improbable that all Cambrian and Lower Ordovician Protremata have a pseudo-
spondylum or spondylium. In the Orthide a pseudospondylium is often suggested, but the

308 CAMBRIAN BRACHIOPODA.

dental plates do not appear to join to form an attached (pseudo) or free spondylium. The
points of attachment of the adductor (central) muscle scars appear to have been directly on
the surface of the valve and not on a raised platform or pseudospondylium.

At my request, and with all the illustrations of this monograph for study, E. O. Ulrich,
who has been studying the Ordovician Protremata, prepared the following notes on the spondylia
of the Cambrian and Ordovician Protremata:

Spondylium. This structure, if we regard the term spondylium as referring only to the typical free or medially
supported umbonal camera or spoon, is of more common occurrence among articulate brachiopods than is usually
believed. Hall and Clarke [1892a, pp. 328-335] discuss the theoretic relations of the spondylium to the deltidium
and suggest an expansion of the former term that seems to me to be disproved by the chronogenesis of the articulate
brachiopods.

The typical spondylium is more or less rhomboidal in outline and corresponds to a ventral muscular area which
is raised above the floor of the valve and formed by the convergence and union of the dental plates. To the concave
surface of this structure the ends of the adductor, diductor, and pedicle muscles are attached.

The manner in which the spondylium is attached to the bottom of the valve is so variable that the feature does
not seem to be of more than generic consequence. It is free in Protorthis and in a related new Ordovician genus; sup-
ported by one or three septa in Clitambonites, Pentamerus, Syntrophia (s.s.), Clarkella, etc.; partly sessile but anteriorly
supported by one or three septa in Finkelnburgia; and wholly sessile (resting entirely on the bottom of the valve) in
Otusia and Orusia, Hoorthis, Billingsella, Huenella, and certain Clitambonitids, Syntrophiide, and Pentameride. The
muscular area of the ventral valve of the Cambrian Orthis-like brachiopods never agrees perfectly with that of any of
the described Ordovician Orthide. In the latter the dental plates of the ventral valve never meet and the area is
more or less distinctly bilobed and very rarely elevated, though it may be so depressed in thick shells as to suggest a
spondylium. In the Cambrian types in question the muscular area is often elevated, commonly suggests and ire-
quently forms a true spondylium, and as a rule is more or less distinctly rhomboidal in outline.. These features,
together with the arrangement and components of the muscle scars of the dorsal valve, suggest a relationship with
the Ordovician Clitambonitidz rather than with the true Orthide.¢

Of the true Ordovician orthids, it seems to me that the groups represented by O. callactis-tricenaria and Dalmanella
(especially the D. subxquata section) are the oldest and most persistent. Both of these types often retain unresorbed
remnants of the deltidium, and in the development of their dental plates and septa and in the shape and arrangement
of their ventral muscular areas they agree with the average Cambrian articulate more closely than do any other Ordo-
vician or Silurian orthoids, with the possible exception of Plectorthis. Thus, except in the matter of surface plication,
the resemblance between Orthis tricenaria and Billingsella romingeri (Barrande) is rather striking. But it is to be
noted that the muscular area in the ventral valve of O. tricenaria (as in Dalmanella subxquata) is blunt and gently
bilobed or obscurely trilobed anteriorly, and not subrhomboidal in outline. Plectorthis whitfieldi has longer and broader
ventral adductor scars than any other Ordovician or Silurian orthoid known to me, and on this account its muscular
area resembles that of Billingsella more closely. Plectorthis whitfieldi is, however, of late Ordovician or Silurian age
and lived at a time of very rapid evolution (and possibly reversion) among brachiopods, when other orthoids of the
same type (Orthis (Billingsella) laurentina (Billings) and Orthis flabellites) were reverting to ancestral characters; or it
may be that they were immigrants from some other area where the older characters persisted.

This difference in shape of the ventral muscular area in the Billingsellide and Orthide is due to the fact that in
the former the median (adductor) scars are always longer and as wide or wider than the lateral (diductor) pair. In
the Orthidze the adductor scars are of the same general shape as the corresponding scars in the Billingsellide, but are
relatively smaller and shorter. They are as long as the diductors in Orthis tricenaria, Plectorthis whitfieldi, and Dal-
manella subsequata, and in others [Dinorthis, Rhipidomella, etc.] they are much shorter and more or less completely
inclosed anteriorly by the revolutionary tendency of the area of the diductors to expand at the expense of the adductors.

A natural division of the orthoids into two families may thus be established:

(1) Ventral muscular area small, obovate or obcordate; adductors reaching front margin of area (Orthis (s. s.), Plec-
torthis, Platystrophia, Hebertella, Orthostrophia, Dalmanella).

(2) Ventral muscular area large, bilobed or elliptical; adductors proportionately small and more or less com-
pletely inclosed anteriorly by the flabellate diductors [Heterorthis, Plxsiomys? deflecta group, Dinorthis, Bilobites,
Rhipidomella, Schizophoria, Orthotichia].

Another well-marked difference between the true Ordovician orthoids and their billingsellid ancestors is in the
arrangement of the muscle scars of the dorsal valve. In the Billingsellidz they are somewhat elongate and more or
less radially arranged (P]. LXX XVIII, figs. 1f-k; Pl. XCIII, fig. 1f; and Pl. XCIX, fig. 2d) and in the Orthidee [Orthis
tricenaria, Plectorthis, Dalmanella, and Orthis tritonia] they are shorter and placed longitudinally. Some of the later
orthoid forms in the second group [Bilobites, Rhipidomella, and Schizophoria] are characterized by a radial arrangement
of the dorsal muscle scars, but the ventral muscular areas are here highly developed and bear little resemblance to
those of the Billingsellide.

a Commenting on this, Dr. Charles Schuchert wrote me: ‘‘This is a very important point. It has often struck me that all the early Cambrian
brachiopods have an incipient spondylium, sometimes free, sometimes supported, or sessile. Out of the sessile forms have developed the true
orthids.”’

4
é

b3
4
Ls
=

THE BRACHIOPOD SHELL. — 309
CRURALIUM.

In the dorsal valve an immature cruralium is seen for the first time in Nisusia festinata
(Pl. C, fig. 1g at d, and fig. 1j at cr) which is without a cardinal process; this appears to be
the first appearance in the Lower Cambrian of a muscle-supporting projection in the dorsal
valve of an articulate brachiopod. In Billingsella a cardinal process is developed (Pl. LXXXYV, —
figs. Ju and 1v) on a low crural thickening. This process is present in Hoorthis and Orthis
and is prominent in Dinorthis, Hebertella, and most of the Orthide, Strophomenide, and Pro-
ductidee. S

A well-developed cruralium in the dorsal valve is first seen in Syntrophia (S. rotundata,
Pl. CII, fig. 4e) of the Upper Cambrian. It is well developed in Clarkella, Conchidiwm, and

other genera of the Pentameracea.
PLATFORM.

Hall and Clarke [1892c, p. 46]* state that—

The specialized postmedian testaceous deposit which has been termed the platform by Messrs. Davidson and
King occurs among Brachiopoda only in the genera Lakhmina [=Neobolus], Lingulops, Lingulasma, Dinobolus,
Trimerella, Monomerella, and Rhinobolus; it constitutes the principal diagnostic character of the family Trimerellidee
of those authors, and in so far as any of these genera possesses this feature, so far, at least, it isa trimerellid. In its
chronogenesis it is accompanied by certain peculiar phenomena. According to our present knowledge, its first appear-
ance is in the little Lakhmina [= Neobolus] from the primordial ‘‘Obolus beds” in the Salt Range of India; but in
American faunas, where the development of the group is best exemplified, it is first met in Dinobolus (in external fea-
tures the most oboloid form of the group) in the later faunas of the Lower Silurian: Black River, Trenton, Galena.
Thereupon follow in the still later fauna of the Hudson group the more pronounced linguloid genera, Lingulops and
Lingulasma. Not, however, until the introduction of the Niagara or Wenlock fauna does the entire group, with the
exclusion of the inceptive linguloid forms, reach its culmination in specific and individual development. * * *
With the disappearance of this fauna the platform-bearing brachiopods virtually became extinct, and we have as yet
no trace whatever of the occurrence of this peculiar feature at any later date or in any other group of these animals.

These authors conclude that it is probable—

that the inception of the platform is due to the slight variation indicated in the mode or rate of formation of the muscular
fulcra in Lingula, and this may itself have been due in part to a simple increase in the size of the muscular bands.

In summing up their conclusions on the source and development of the platform in the
trimerellids, the statement is made that ‘‘we are confronted with the interesting phenomena
of a similar resultant attained along different lines of development.’’ This is expressed in a
diagram in which Obolella and Lingulella are taken as the first stages of two lines of develop-
ment. On the line of Obolella come in succession Obolus, Etkania, Dinobolus, and Trimerella.
On the line of Lingulella come in succession Lingula, Lingulops, Lingulasma, Trimerella,
and, as an offshoot from Lingulasma, Monomerella and Rhinobolus. Lakhmina [= Neobolus]
is placed in a central line between Obolus and Lingulella [Hall and Clarke, 1892c, p. 52]. For
the full discussion of the views of Hall and Clarke the student should consult the original
work [Hall and Clarke, 1892¢, pp. 46-55].

In the course of my studies of the Cambrian brachiopods I came to the conclusion that
the platforms so far as developed were the result of shell secretion beneath and about the points
of attachment of the muscles, also beneath the visceral cavity. In the dorsal valve of Rus-
tella (Pl. I, fig. le) from the Lower Cambrian, the most primitive type of brachiopod known
to me, the central and anterolateral muscle scars are slightly raised above the general level
of the interior of the valve; many natural casts of the interior of the ventral valve fail to show
traces of the points of attachment of the muscles.

I have assumed that Obolus was divergent from the same stock or radicle as Rustella, and
that Lingulella is an early divergent from Obolus. (See schematic diagram, p. 317.) None
of the Lower Cambrian species of Obolus or Lingulella known to me has any unusual thickening
of the valves over the visceral area or about the muscle scars, but in the Middle and Upper
Cambrian it is not uncommon to find more or less indication of it. Obolus mickwitzi (Pl. X,
figs. 1, lak) of the Middle Cambrian is a striking example, and Obolus apollinis (Pl. VII) of

a Observations on the development and function of the platform in the inarticulate Brachiopoda.

310 CAMBRIAN BRACHIOPODA.

the Upper Cambrian affords fine illustrations of the general thickening of the shell beneath
the visceral area in both valves, while the points of attachment of the muscles may be depressed
(Pl. VII, figs. 10 and 17) or elevated (Pl. VII, figs. 9 and 14). The thickening of the shell is
also well shown by the ventral valves of Obolus (Schmidtia) (Pl. XIV, figs. la, 3a, and 4a)
and less well by the dorsal valves (Pl. XIV, figs. 1c, 4c, and 4d). Obolus cyane (Pl. X XVII,
fig. 4b) from the Lower Ordovician has an unusually well-developed thickening beneath the
visceral area of the dorsal valve. Many other illustrations might be given from Obolus and its
subgenera.

' In Lingulella and its subgenera there is a striking development of the primitive or

early stages of the platforms, and they are present in many species—L. acutangula (Pl. XVII).

and L. granvillensis (Pl. XXII, figs. 1b and 1d) of the Lower Cambrian and LZ. dubia (PI.
XXIV, figs. 4 and 4a) and L. ino (Pl. XXVI, fig. 4) of the Middle Cambrian. Of Upper
Cambrian species only the small L. ferruginea shows a slight thickening of the valves beneath
the visceral area (Pl. X XIX, figs. Ir and 1s).

From Lingulella there appears to have been an offshoot in Middle Cambrian time in Obolus
(Fordinia) perfectus (Pl. LXIII, figs. 10, 10a-d) that developed a strong tendency toward the
formation of a rudimentary posterior thickening in the interior of the valves. Two species,
Obolus (Fordinia) bellulus (Pl. LI, figs. 3, 3a-f) and O. (f.) gilberti (Pl. LI, figs. 5, 5a-d)
from the Upper Cambrian, also show the same tendency. The rudimentary platform of O.
(Fordinia) perfectus (Pl. LXIII, figs. 10a and 10c) is intermediate in development between
those of Obolus apollinis (Pl. VIL) and Elkania desiderata (Pl. LI). The position of the central
group of muscle scars, at the anterior sloping ends of elevated ridges, marking the path of advance
of the scars with the growth of the shell, is beautifully shown in figure 10a of the ventral valve
of O. (F.) perfectus (Pl. LXIII). In the dorsal valve of the latter species there is marked
thickening of the shell beneath the visceral area, and a marked median septum or ridge just in
front of the cardinal area (Pl. LXIII, fig. 10c) is very suggestive of a cardinal process.
The ventral valve of Hikania desiderata (Pl. LI, fig. 1) has a strong, solid, rudimentary platform
into which the interior cardinal area is blended, and the position of the central group of muscle
scars is on the front slope of the platform; in the dorsal valve (Pl. LI, figs. 1e and 1d) a rudi-
mentary platform is also clearly indicated. The dorsal valve of Elkania ambigua (Pl. LI, fig.
2c) may have a fairly strong rudimentary platform or be without it (Pl. LI, fig. 2b). Elkania
ida (Pl. LI, figs. 4b and 4c) has the rudimentary platform finely developed in both valves.

Lingulasma schucherti [Hall and Clarke, 1892c, Pl. II, figs. 17-23] of the Upper Ordo-
vician appears to be the best expression of an intermediate form between Obolus (ordinia)
(Pl. LXIII, figs. 10, 10a-d) and the forms represented by Dinobolus [Hall and Clarke, 1892c,
Pl. [Vz] and T. rimerella [Hall and Clarke, 1892c, Pl. IVa] of the Silurian, but it is quite prob-
able that Lingulasma was not in any way intermediate between Fordinia and the trimerellids.
It seems to represent a side branch of Lingula.

The line of development of the platform to Ordovician and Silurian forms seems to have
been from some Obolus-like form, as Fordinia to Neobolus (Pl. LX XX1I, figs. 2e and 2f), and
thence to Dinobolus. I thought at one time that Elkania might be a possible ancestral line
to the Trimerellide, but, after carefully considering the position of the rudimentary platforms,
T concluded with S oerirent that Hlkania was an ‘ofishoot from Obolus that did not leave any
known descendants.

SEPTA.

The septum of the dorsal valve of the Obolide is usually in the form of a narrow ridge, and
is not a true septum in the usual sense, which is that a septum is a thin median vertical plate
of variable height, terminating freely or supporting a spondylum. Well-developed septa occur
in the cat ile as supports beneath the spondyla (Pl. CIII, figs. 3d and 3e; Pl. CIV,
figs. 2¢ and 2d).

DENTAL PLATES.

Dental plates first appear, so far as known, in the Protremata as obscure processes supporting

the teeth of the ventral valve, one on each side of the delthyrium. One of the oldest examples

ee a ee

ee ee) oo

Steg Gre or,

THE BRACHIOPOD SHELL. 311

is that of the Lower Cambrian Nisusia festinata (Pl. C, fig. 1j), where the plates form the support
of the teeth and also outline a rudimentary spondylium. Protorthis of the Middle Cambrian
- has a spondylium on each side of which are the teeth supported at each of the outer angles next
to the cardinal area (Pl. XCIX, fig. 3b). Dental plates undoubtedly existed in other genera
- of the Protremata of the Cambrian, but they have not been observed.

VASCULAR MARKINGS.

The most prominent of the vascular impressions are the pallial smmuses or main vascular
canals. Usually all that is impressed on the inner surface of the valves are the two main trunks
that diverge from near the apex or beak of the valves and skirt the margin of the visceral area.
In rare instances the impressions of the secondary branches of the main sinuses are preserved.

ATREMATA.

None of the shells of the genera of the Paterinide show more than the bases of the main
trunks of the vascular system, but in Obolus and Lingulella and their subgenera there are numer-
ous illustrations of the main vascular canals and in a few instances of the secondary canals.

Obolus apollinis (Pl. VII) of the Upper Cambrian has the vascular system as well developed,
judging from the impressions left by it on the interior of the valves, as in the mantle of recent
Lingula. In the closely allied form, Lingulella granvillensis (Pl. XXII, figs. 1b and 1d), from
the Lower Cambrian, there is every reason to think that the vascular system has reached its full
development. The main vascular trunks, lateral canals, and peripheral canals are all indicated
in the ventral valve (Pl. XXII, fig. 1d). Striking illustrations of the preservation of the mark-
ings of the vascular system are shown in many of the illustrations. (See Pl. VIII, fig. 1d; Pl. XII,
figs. 1c, le, 9, and 9a; Pl. XIII, fic. 1m; Pl. XV, fig. 11; Pl. XVII, figs. Uh and 1j; Pl. XXXVI,
fies. le and 1d; Pl. XX XVII, fig. 1c; and Pl. XX XVIII, figs. 2b and 2d.)

In Bicia (PI. L), one of the oldest of the Obolide, the main vascular trunksare very strong,
and they are prominent in Dicellomus (Pl. LII, figs. 1d and 1j; Pl. LIII, figs. 1d, 2, and 4a).

NEOTREMATA.

In the Neotremata, Obolella, the most primitive form, has the vascular trunks developed
(PI. LIV, figs. 22-n) on a scale comparable with those of Obolus, but, as is usually the case
among Cambrian brachiopods, the calcareous shells do not appear to bear the impressions of the
secondary canals as well as do the chitimous or phosphatic shells. _The main vascular canals of
Botsfordia (Pl. LYVII, figs. 4¢—m; Pl. LEX), Linnarssonella (Pl. LXXIX, figs. 1m—-p, 2, and 2a),
Trematobolus (Pl. LX XXIIT), Yorkia (Pl. LX XXII, figs. 1h and 2), Schizambon (Pl. LXXXIV,
figs. la, le, 2d, 3b, and 3c), and Dearbornia (Pl. LUX XXII, figs. 7b and 7c) are all strongly devel-
oped. In Acrothele are found some of the most beautiful examples of the preservation of a highly
developed system of vascular canals (PI. LVI, figs. la-d, 3b, and 3c; Pl. LXI, figs. 1e and 1d).
Acrotreta has relatively large vascular trunks (Pl. LXIV, figs. 1i, 1j, and 2c; Pl. LXV, figs. 1f,
1g, 3c, and 6; Pl. LX XIII, figs. 4c and 6), but no traces have been seen of the lateral canals.
The main trunks of Acrothyra are also large (Pl. LX XVI, figs. 4a and 4b). Discinopsis (PI.
LXXXII, figs. 5a—b) has two narrow, long, maim trunks that originate back of the line of the

opening of the pedicle tube.
PROTREMATA.

In Billingsella the great size of the main vascular trunks (Pls. LXXXV—XC) is character-
istic of the genus. The manner in which the anterior branches of the main trunks pass outward
toward the border is finely shown in specimens of B. plicatella (P]. LXXXVI, fig. 31). The
dorsal valve of B. exporrecta (Pl. LX XXVIII, fig. 1k) has two strong apparently main sinuses
on each side; the inner pair, however, may not be casts of the vascular sinuses, but may indicate
grooves made by the path of advance of the attachments of the posterior adductor muscles.

The vascular system of Nisusia (Pl. C) and its subgenus Jamesella (Pl. CI), Protorthis
(Pl. XCTX), and usually of Hoorthis, has left no traces of its presence on the shell. On some

312 CAMBRIAN BRACHIOPODA.

examples of Finkelnburgia (Pl. XCIII, figs. 1d, 1f, 2, and 2b) there are indications of large main
trunks, and in Orusia (Pl. XCVIII, figs. le and 1p) narrow trunks are seen. Only one among
many hundreds of specimens of Hoorthis (Pl. XCI, fig. 3b) shows traces of the main trunks.

Among the Syntrophiide, Huenella abnormis (Pl. CII, figs. 2b and 2h) shows that the main
trunks were of large size. I have not seen any interiors of the shells of the Strophomenidz from
the Cambrian system.

This brief review proves that the simple primitive type of the circulatory system, as developed
in the main vascular canals, their laterals, and the peripheral canals of the mantle, was fully
developed in Lower Cambrian time, and that this type persisted throughout Cambrian time.
The modified form of the canal system of the Craniide has not been observed, nor has the
complex canal system of the Ordovician and later orthoids [Hall and Clarke, 1892c, Pls. Va, Ve,

VI, and VIaj.
MUSCLE SCARS.

It is only within a few years that material has been available from Cambrian rocks that
could furnish data for a description of the muscle scars and by them an outline of the muscular

system of the Cambrian brachiopods.
ATREMATA.

In the Atremata this has been most thoroughly worked out for Obolus by Mickwitz (1896),
and an outline may be found in this monograph under the description of the genus Obolus. The
terminology used in this monograph is mentioned on page 292.

In the most primitive form of brachiopod known to me, Rustella edsont, the muscle scars of
the dorsal valve, so far as known, indicate that the system of scars was essentially the same as
in Obolus. In the dorsal valve the central scars (Pl. I, fig. le) are preserved; also the anterior
portion of the outline of the parietal band, which indicates the position of the anterolateral
scars. Although we have a number of good natural casts of the interior of the ventral valve,
no traces of vascular markings or muscle scars have been observed. So far as known none of
the many hundreds of specimens of various species of Micromitra have preserved any definite
outlines of the muscle scars, and the same is true of Mickwitzia and Helmersenia.

Obolus and Lingulella and their subgenera all have the same general grouping of the
muscle scars as described under Obolus. For Obolus these are well shown in O. apollinis (PI.
VID); for Lingulella by L. acutangula (Pl. XVII); for the subgenus Westonia by Obolus (Westonia)
escasoni (Pl. XLIX, figs. 1a, laa, 1c, and 1d). The same general arrangement of the muscle
scars, so far as known, is found in Bicia (Pl. L), Elkania (Pl. LI), and Obolus (Fordima) (Pl.
LXIII, figs. 10aand10c). In Dicellomus the central and the outside and middle lateral scars are
located in front of the visceral area, as in Obolus, but the anterolateral and transmedian scars
are combined in one large cardinal scar (Pl. LIT, fig. 1¢ at el), as in Acrotreta (Pl. LXIV, figs.
2c and 2d); in the dorsal valve the central and anterolateral scars are as in Obolus, while the
transmedian, outside laterals, and middle laterals appear to be grouped in one large cardinal scar
(Pl. LIL, fig. 1i at cl). The combining of the muscle scars of the posterolateral region of the
valves in one large scar in this genus of the Atremata foreshadows the typical large cardinal
scar so characteristic of the Neotremata.

NEOTREMATA.

In Obolella (Pls. LIV and LY) the arrangement of the muscle scars, so far as known, is that
of Obolus, but with a tendency on the part of the posterolateral scars to close m toward each
other; this tendency is carried into effect in Botsfordia (Pl. LIX, figs. 1k and In; Pl. LVU,
fig. 4k; and Pl. LXII, figs. 5g and 5i). In the dorsal valve of Botsfordia pulchra (Pl. LXII,
fig. 5h) the transmedian and middle lateral scars appear to be distinct, but in figure 51 and in
all ventral valves, figures 5g and 5j, a single large scar appears to be present. InLinnarssonella,
which I have placed as the descendant from the Acrotreta stock (schematic diagram, p. 317),
the posterolateral scars are all grouped in both valves in a large cardinal muscle scar (Pl.
LXXIX, figs. 1k-p). The muscle scars of the central portion of the valves remain essentially
as in Obolus.

-

THE BRACHIOPOD SHELL. 313

The system of muscle scars in Trematobolus (Pl. LX XXIII) is, so far as known, that of
Obolus, with a modification probably of the position of the scars of the pedicle muscles; of the
latter, unfortunately, nothing is known. Dearborma (Pl. LX XXII, figs. 7b and 7c) has the same
arrangement of the muscle scars as Trematobolus, but of the muscle scars of the other genera
descendant from the Trematobolus stock we know very little. The interiors of Siphonotreta
(Pl. LXXXI, figs. 6c, 6d, and 6e) indicate an arrangement somewhat like that of Trematobolus.
Yorkia, Orbiculoidea as known in the Cambrian, and Philhedra show nothing of the muscle
sears. Schizambon (Pl. LX XXIV) appears to be related in its muscle scars to Trematobolus.

The muscle scars of Acrothele, Acrotreta, and Acrothyra agree in having the posterolateral
scars united on each side in one large cardinal scar situated in the posterolateral region of the
valves. The central and anterolateral scars of the dorsal valve are variously situated (PI.
LVILI, figs. 5f and 5h, and Pl. LX, fig. 11) in the central portion of the interior of the valve,
but not more so than in the dorsal valve of Obolus. In the ventral valve the outside and mid-
dle laterals and the central scars are more or less contracted, and drawn back toward the small
visceral area about the pedicle opening; the individual scars have not been seen except in one
specimen of Acrotreta argenta (Pl. LXVII, fig. 5b). In this species the visceral area is unusually
large and the positions of the outside lateral and central scars is shown; the anterolaterals are
not delimited. Another species of Acrotreta, A. ophirensis (Pl. LX XIV, fig. 1e), has an unu-
sually large visceral area, but, although the area of the muscle scars is defined, the individual
sears can not be seen. No reference has been made to the umbonal muscle scars, as they are so
rarely preserved. They are well developed and shown in Obolus and Lingulella, and it is
highly probable if not certain that some form of umbonal muscle existed in all of the inarticu-

late brachiopods. .
PROTREMATA.

The muscles of the Protremata are limited to three sets: diductors, to open the valves;
adductors (centrals), to close the valves; and the pedicle muscles.

In Kutorgina, the atrematous progenitor type of the Protremata, the anterior and poste-
rior adductors (equal to the anterolateral and central scars, respectively) are known in the dorsal
valve (Pl. V, fig. 1h), but nothing is known of the point of attachment of the diductor muscles
in the dorsal valve or of any muscles in the ventral valve. The muscle scars are preserved in
Billingsella in the ventral valve within the area of the pseudospondylium. The diductors
probably occupied the outer divisions of the tripartite pseudospondylium and the adductors
the central section. This is well shown in many specimens (Pl. LX XXV, figs. 1m and Ip;
Pl. UXXXVI, figs. 3g, 31, 3], 3k, 3m, and 4b; Pl. LX XXVIL, figs. 5b, 5c, and 7; and Pl. XC,
figs. 2g, 2h, and 21). The diductors appear to have followed closely in the line of the scars of
the main vascular sinuses if the tripartite pseudodeltidium is considered to have been wholly
taken up by the points of attachment of the muscles. In the dorsal valve the adductor scars
are often prominent (Pl. LX XXVIII, figs. 1g, 1h, 1], and 1k), also the cardinal process to which
the diductor muscles were attached. The interiors of the ventral valves have not thus far
shown muscle scars.

The muscle scars of the ventral valve of Nisusia and its subgenus Jamesella, and those of
Finkelnburgia, Orusia, and Protorthis, were probably gathered on a pseudospondylium or,
when the latter is not defined, on the bottom of the valve beneath the umbo, as in Hoorthis.
In an obscure specimen of the dorsal valve of Portorthis quacoensis (Pl. XCIX, fig. 2d) the pos-
terior adductor scars appear to be preserved.

In the dorsal valve of Finkelnburgia the adductors are finely shown (Pl. XCIII, fig. 1f), also
a rounded, posterior central depression in which the diductors may have been attached.

Among the Cambrian Syntrophiide muscle scars have been discovered in Huenella abnor-
mas of the Upper Cambrian. In the ventral valve (PI. CIII, fig. 2b) the adductor and diductor
scars are preserved on the spondylium, and dorsal valves (Pl. CIII, figs. 2f, 2i, and 2j) show
the adductors in fine preservation, also the cruralium to which the diductor muscles were
attached. The muscle scars of this species are of unusual interest, as the ventral valve has a
spondylium to which the pedicle, the large diductor, and the smaller scars of the adductor
muscles were attached.

314 | CAMBRIAN BRACHIOPODA. |

x

PEDICLE TUBE AND APERTURE.

ATREMATA.

When the pedicle rests in furrows on the areas of the valves, as in Obolus (Pls. VII and
XIV), it pertaims to both valves, but with the deposition of a narrow band of shell about it on
the ventral valve it strictly pertains to this valve alone, although it may still rest against.
the area of the dorsal valve before passing through the semitube of the ventral valve. The
transition from the deep but open pedicle furrow of the ventral valve of Obolus to the inclosed
sheath or tube of Obolella is found in Dicellomus politus. In this species there has been a deposit
of shelly matter that rises up from the sides of the pedicle furrow on the ventral valve and
arches slightly inward, almost forming a tube in places; what remains of this semitube is shown

by figures 16A and 16B.
NEOTREMATA.

The earliest and simplest stage of development of the pedicle tube when it completely
surrounded the pedicle is found in Obolella of the Lower Cambrian (Pls. LIV and LV). In this
genus the deep pedicle furrow of the ventral valve
of Dicellomus has been covered over just at the
apex of the cardinal area so as to form a simple
ring or tube about the pedicle. In the next stage,
as shown by Botsfordia (Pls. LVII and LIX), the
pedicle has advanced its opening to the front side
of the apex and the tube between it and the furrow
in the area is a little stronger and a trifle larger.

In Linnarssonella (Pls. LX XVIII and
LXXIX) the opening of the pedicle tube is close
FIGURE 16.—Dicellomus politws (Tall). A, Interior of ventral valve to the posterior margin and the Obolella-like struc-

(fsp, pseudospondylium or pedicle plate; i, transmedian scars; j, ture in both valves is very striking. This is best
se teas vests; eared) seen by comparing the casts of the interior of the
a strongly developed area (fsp, pseudospondylium or pedicle ventral valves of Linnarssonella (Pl. LXXIX,
ae inside section of area; f, flexure line; a’, outside oe figs. 3c-g) with those of Obolella atlantica (Pl. LM,

The specimens represented by figures16A and 16B are from figs. 1{-h). Tn both Sree the cast of the pedicle

Locality 79s, Upper Cambrian “St. Croixsandstone” at Hudson, tube is in the same position in relation to other
RS ek eae See ae Ge eee eave parts, and the external opening of the pedicle tube
is at the apex above a low false cardinal area.

The depressed forms of Acrothele, with the apex near the posterior margin, appear to have
been descendant from the Obolella stock but to have reached a stage of development more
advanced than any known form of the Cambrian genus Obolella. Acrothele bellula (Pl. LVIIL,
figs. 5, 5a—h) of the Middle Cambrian appears to be one of the oldest forms and to have retained
in its ventral valve characteristics of its obolelloid ancestors. In the ventral valve the pedicle
tube penetrates the thickened apex of the shell and there is considerable space between the
pedicle aperture and the posterior margin; the tube and aperture are essentially the same in all
the species of Acrothele, differing only in details due to a rather narrow range of position and the
varying thickness of the shell. The genus Schizopholis (Pl. LX XXI, figs. 1, la-c) has a more
nearly vertical posterior slope and distinctly marked false area, in this respect resembling
the large group of species referred to Acrotreta. The pedicle tube and aperture of the latter
are of the same type as in Acrothele, differing only in form and position within a narrow range.
Acrothyra also shows little variations. Discinolepis (Pl. LX XXI, figs. 3 and 3a) has the pedicle
opening more advanced and appears to be a form intermediate between Acrothele and Acrotreta.

DISTRIBUTION. 315

. The pedicle tube of Keyserlingia (Pl. LXXXI, fig. 4c) apparently opens into an elongated
depression in the shell back of the apex of the ventral valve; the tube is a passage through
a thickened mass of shell which is deposited about the pedicle and which is especially well
developed in old shells (Pl. LX XXI, figs. 4a and 4d).

PROTREMATA.

A pedicle tube or opening is found in the genus Billingsella of the Lower Cambrian, the
characteristic opening being at the apex of the delthyrium (fig. 65, p. 750). It has not been
observed in Nisusia (Pl. C) nor in the subgenus Jamesella (Pl. CI), nor in any other genus or
subgenus of the Protremata of the Cambrian fauna. This may be owing to the absence of a
deltidium in the adult stages of the shell found, to its being covered by the incurved beak, to
the difficulty of working out or uncovering the deltidium so that it can be seen, or in all proba-
bility to the permineralization of the shell and the generally coarse nature of the sediments
deposited with the shells. It may be that the opening was closed naturally in the adult stages
as in some of the Ordovician Clitambonites. Even in Billingsella, where the material is abundant
and well preserved, it is qnly rarely that an entire deltidium is obtained and very rarely that
the minute pedicle opening can be seen at its apex.

OLD-AGE CHARACTERS.

I have not given special attention to old-age characters during the progress of the study
of the Cambrian brachiopods. The variations due to old age during the gerontic period appear
in the unusual thickening of the shell of Obolus apollinis (Pl. VII), but old age is not indicated
on the exterior of the shell (Pl. XIV, figs. 6.and 6a). The areas of attachment of the muscles in
Obolus mickwitzi (Pl. X) suggest old age, and the strong concentric ridges at the front of the
valves is another phase of old-age conditions. Obolus (Lingulobolus) (Pl. XVI), in its thick
shell, large deep muscle scars, and convex valves indicates an old-age form derived from Obolus.
In Keyserlingia buchi (Pl. LXXXI, figs. 4a-e) the interior shell growth associates the species
with old-age forms.

There is abundant material for study of many of the species described in this volume that
may, when carefully worked up and studied, give some interesting results in relation to changes
in the shell during the mature (neologic) and old-age (geratologic) periods of growth. .

DISTRIBUTION IN CAMBRIAN STRATA.

We do not know of any brachiopods in strata older than that containing the Mesonacidse
or Lower Cambrian fauna. That such existed in pre-Cambrian time seems almost certain when
the advanced stage of development of some of the earliest-known forms is considered.

In the following diagram the known occurrence of the families of brachiopods in strata of
Cambrian age is graphically shown. The diagram is based on the data contained in the table
(p. 112) givmgasummary by families. The Obolide, with 6 genera, 9 subgenera, 186 species, and
14 varieties, has the greatest development, and this family continues into the base of the Ordo-

‘vician with 4 genera, 3 subgenera, 41 species, and 1 variety. The Acrotretide has 6 genera,
1 subgenus, 100 species, and 20 varieties, with the greatest development in the Middle Cambrian
and with a smaller representation in the Lower Ordovician. The Billingsellide, with 9 genera,
2 subgenera, 91 species, and 12 varieties, has a strong line of development from the upper
Middle Cambrian and passes into the Ordovician, where it disappears. The three families
mentioned include about 48 per cent of the genera, 80 per cent of the subgenera, 80 per cent
of the species, and 79 per cent of the varieties included in the Cambrian Brachiopoda. The
development of genera of the remaining families containing 3 genera or more is as follows:
Paterinide, 3; Obolellidz, 4; Siphonotretidx, 6; Syntrophiide, 3; or 16 genera of the 23 outside

316 CAMBRIAN BRACHIOPODA.

of the Obolide, Acrotretids, and Billingsellide, which contain 21 genera. The remaining

7 families include 7 genera.
Of the 44 genera from the Cambrian, 19 occur in the Lower Cambrian, 31 in the Middle

Cambrian, and 20 in the Upper Cambrian.

Zz
es
LOWER MIDDLE UPPER |w2
E SUPERGAMITIES CAMBRIAN | CAMBRIAN | CAMBRIAN |36 FAMILIES
= |) 3 =/2)
= i) [ea
= iS (eo)
=) G)
Nes
z oo Pentameracea 2 Syntrophiidae
<=

Strophomenacea Strophomenidae

Orthacea Billingsellidae

Schuchertinidae

Kutorginacea
Kutorginidae

Craniacea Craniidae
& Discinacea Discinidae
£
£ Acrotretacea Acrotretidae
< 5
||| 24 Siphonotretidae
s Siphonotretacea
©) Obolellidae
=
ia ;
2 Obolidae
=| Obolacea
2 2 Curticiidae
2
= Paterinidae
Rustellacea
Rustellidae

FIGURE 17.—Diagram illustrating known distribution of families in Cambrian strata. «

EVOLUTION OF THE CAMBRIAN BRACHIOPODA.
SCHEMATIC DIAGRAM.

In order to formulate, so far as possible, in a graphic manner my conception of the evolution
and lines of descent of the Cambrian Brachiopoda, gained by the investigations described in
this monograph, a schematic diagram (fig. 18) has been prepared.

This diagram is necessarily tentative and incomplete, but it will serve to point out my
present conceptions of the lines of evolution of the various genera, and it shows clearly the very
rapid development of the primitive atrematous genera in early Cambrian time.

The genera identified from each of the three divisions of the Cambrian may be ascertained by
glancing at the columns headed Lower, Middle, and Upper Cambrian for the generic and
subgeneric names included in each column.

The most primitive but not the oldest species known to me from the Cambrian formations
is Rustella edsoni (P1. I, figs. 1, la-e). This is found in association with Olenellus thompson
in Vermont, where it occurs at nearly the summit of the Lower Cambrian, and not low down
toward the base of the Cambrian system. Probably the oldest-known brachiopod, or the species
lowest in the stratigraphic series, is Trematobolus excelsis (Pl. LX-XXII, figs. 8, 8a-d). This is
far advanced in development and must have had a long line of descent from the protegulum
stage. Another very ancient type is Micromitra. A species with ornamented surface (J.
(Iphidella) lowise) occurs 2,850 feet down in the Lower Cambrian of the Canadian Rockies and
Micromitra (Iphidella) pannula (P\. TV) is abundant in the upper portion of the Lower Cambrian.
Micromitra (Paterina) labradorica (P1. I1) is found deep in the Lower Cambrian of New Brunswick

(te > Sr aes te Se

a

EVOLUTION.

317

aldIpey wWnjnsazo14

| LOWER CAMBRIAN MIDDLE CAMBRIAN UPPER CAMBRIAN ORDOVICIAN
i Eostroph ;
Wimanella: Wimanells ee oe
y \ Eoorthis = Eoorthis ALG Baars
een Sn Of
ta 7 : Orusia g
a 7 Orusia Q———— +)
| ne _-OtusiaO a
illimerse’ll L Billingsélla Billingsella a
Bi mes se) << O S
iV Jamesella es es a
} esena ©) Jamesella =
if NisusiaO Nisusia ; O : S
/ x torthi torthi
yi (irra one o. rotorthis rotorthis 6
PENS Sue OLoperia :
Hyg ise) ESE eee LEO Syntrophia E Syntrophia 2 Syntrophia
Me eee ®t} @lclaiella

/ Mickwitzia OQ

|phidella ©

2

ee aa t-O Volborthia
/ Micromit Mi it Micromitra --~
; Beattie icromitra icromitra | ZG
/ awe Paterina Paterina Paterina O
Pi Pee ety Rustella _E-LHicellomus | _Oicellomus
Bici Beat Elkania Elkania : .
ee Og o> ——©) ©-©OBroggeria
Sie ae paren aly see? Bar tO) Neobolus Se uum ste a
ed ee _OFordinia CurticiaQ | -t-O Acritis mn
Y ‘O: Obolus zee Cisels = Chellis aaa ae Obolus ca
\ ‘ me Ss IBS . >
Mi ane aS Mickwitzella@ Olingu-
\ *, *\. Westonia Westonia letealhas
\ S& oO O Westonia
iN \ Delgadella© ‘© Palzobolus
\ \ . pra . .
\ CO -Lingulella Zi Lingulella = Lingulella — Lingulella
\ ie ~..___Leptembolon q5~.__Lingula
‘ Po Lingulepis Lingulepis |_© Lingulepis
KO) Quebecia _© Schizopholis
aN Botsfordia io
ie O O

\

oO Trematobolus
Yorkia©O

to “ Obolella OC

O Acrothele ~~] gee Acrothele

Botsfordia
_© Discinolepis
~~ _ORedlichella

Linnarssonella

Acrothele

FIGURE 18.—Schematie diagram of evolution of Cambrian Brachiopoda.

©) Acrothele ss
Linnarssonella =
asa © °
DiscinopsisO eo)
a m
Acrotreta Z Acrotreta Acrotreta > <
BSxe ~~, Acrothyra =
“.__“Orbiculoidea Orbiculoidea Orbiculoidea,
Trema- NP RIeE Philhed
ese, Obie — te
S Schizambon Schizambon
si eens pees Slizaaet: (ous Sdieiban
DeafioraO ~s.,_Keyserlingia 5), |Siphonotreta,
|e

318. CAMBRIAN BRACHIOPODA.

and is the oldest brachiopod known from the Atlantic Province. Bicia (Pl. lL), Obolella (Pls.
LIV and LY), Quebecia (Pl. CLV), Botsfordia celata (Pl. LIX), Acrothele bellapunctata (Pl. LVI,
figs. 3, 8a-b), A. decipiens (PI. LVIII, figs. 3, 3a-d), A. woodworthi (Pl. LX, fig. 6), Acrotreta
emmonsi (Pl. LXV, fig. 6), A. primeva (Pl. LXIX, figs. 1, 1a-f), and Yorkia (Pl. LX XXII) occur
with other forms in the upper portion of the Lower Cambrian fauna. All of these examples of
inarticulates indicate that the brachiopod fauna had advanced far in its evolution in Lower
Cambrian time. Among the progenitors of the Protremata, Kutorgina (Pl. V) occurs in the
Mesonacide fauna, and Schuchertina (Pl. LI) of the Middle Cambrian probably springs from
the Autorgina stock in Lower Cambrian time. Among the articulates we find, of the order
Protremata in the Lower Cambrian, several species of Billingsella (Pls. LXXXVI-LXXXIX),
Nisusia (Pls. C and Cl), and Swantonia (Pl. CIV), all from the upper zone of the Mesonacidze
fauna. (See lists of genera and species, pp. 98-109.)

ATREMATA.

The most primitive form of the Atremata known to me is Rustella edsoni (Pl. I, figs. 1, 1a-e)
of the upper portion of the Lower Cambrian terrane. It is without a false cardinal area, and
there is only a slight indication of a pedicle furrow; some of the less well-preserved shells suggest
the protegulum stage of the Brachiopoda. Mickwitzia (Pl. VI, figs. 1’’ and 3), Helmersemia (PI.
LXIII, figs. 7b and 7d), and Volborthia (Pl. I, figs. 6 and 6e) have an obscurely defined false
cardinal area on the ventral valve. In Helmersena the pedicle opening is produced by the
gaping of the valves; in Volborthia (fig. 33, p. 366) it is produced by the bulging of the cardinal
margins. In Micromitra (Pls. I, III, and IV) the posterior margins of the valves may be
nearly closed as in M. pealei (Pl. III, figs. 3b and 3e’), or have a more or less open delthyrium
as in M. ([phidella) pannula (Pl. IV, figs. 1d, 1f, 2a’’, 2b’, 4a’, and 4d’). In Ourticia (Pl. 1,
figs. 2’, 2b, 2a’’, and 2d) the open delthyrium is more developed than in Micromitra, although
the cardinal area is not outlined. Curticia appears to be a form intermediate in character
between Micromitra of the Paterinide and Obolus of the Obolide. It shows no trace of a pseu-

dodeltidium or any closing of the delthyrium by an extension of the area across it. In the —

graphic systematic scheme (p. 317) it is placed as a family descendant from Obolus.

In the diagram on page 317 the lines of descent of the various genera are graphically out-
lined, but our information is often so fragmentary that the scheme is necessarily imperfect. In
this the Rustella type of the upper Lower Cambrian is assumed as the known form that most
nearly approaches the protegulum stage or the first stage in which it would be possible to have a
brachiopod preserved as a fossil. From the pre-Rustella radicle Micromitra developed in early
Cambrian time and continued nearly to the close of the Upper Cambrian, giving rise in the
Lower Cambrian to Mickwitzia and in the Upper Cambrian to Helmersenia and Volborthia.

Obolus, branching from the Rustella protegulum radicle, is first known in the Lower Cam-
brian a little later than Micromitra. It persisted on into the Ordovician, giving rise in early
Middle Cambrian time to its subgenera Palzobolus and Westonia, in late Middle Cambrian time to
Fordinia and to O. (Acritis?) rugatus. Other subgenera, Schmidtia, Bréggeria, and Mickwitzella,
appeared in late Upper Cambrian or early Ordovician time. icia is taken from the pre-Obolus
radicle. Dicellomus appears in central Middle Cambrian strata and continues into the Upper
Cambrian. It probably originated in the Bicta phyllum in Lower Cambrian time. Elkania
begins in central Middle Cambrian strata and continues well into the Upper Cambrian. It
appears to have been an offshoot from Obolus without known direct descendants. Neobolus,
with its peculiar platforms pointing to the future Trimerellide, is probably a descendant from
some Lower Cambrian form that branched off from Obolus. The descendants of Neobolus, if
such existed, are unknown in the late Middle and Upper Cambrian. Curticia is given as an
offshoot from Obolus in Upper Cambrian time and Lingulobolus in the Lower Ordovician.
Fordinia appears to have been an offshoot from Obolus in Middle Cambrian time and to have
disappeared without descendants.

EVOLUTION. alg

It is assumed that Lingulella-like forms developed from primitive Obolus in early Cambrian
time, since the genus is first known from the lower portion of the Lower Cambrian and is known
to occur throughout the Cambrian and into the Ordovician. The subgenus Lingulepis appears
in Middle Cambrian time and continues on into the Lower Ordovician. Little is known of
Delgadella of the Lower Cambrian, but from its form it is referred to the Lingulella phyllum.
Lingula is probably descendant from Lingulella in late Cambrian time. Lingulella davisi (PI.
XXXI, figs. 6e, 6f) is quite similar to Lingula, as are Lingulella lens, L. concinna (Pl. XXXIII),
and other Upper Cambrian species. The subgenus Leptembolon branches off from Lingulella
in late Upper Cambrian time.

Matthew [1902b, p. 98] has given a diagram showing “Conjectural Lines of Descent of
the Canadian Oboli with Reference to the Oldest Known Atremata.” This diagram and the
discussion following it are based upon Matthew’s observations in the Cambrian section of New
Brunswick and Nova Scotia and his interpretation of the genera and species. The greater
opportunity offered by larger collections from a much wider field has so changed the data upon
which his conclusions were based that I shall not enter into a discussion of them.

Kutorgina (Pl. V) is assumed to have branched off from the Micromitra radicle in pre-
Cambrian time, and from its line of descent or radicle Schuchertina (Pl. LI, figs. 6, 6am) is
taken off. Both of these genera are placed on the border line between the Atremata and

Protremata.
NEOTREMATA.

The progressive increase in the differences in form and the relations of the two valves in
the genera of the Neotremata is best seen by a glance at the diagram on page 317. In this an
Obolella-like type is descendant from a simple form like the Rustella radicle and from this radicle
the Acrotretide diverges. Acrothele, with its great vertical range from the Lower Cambrian to
the Ordovician and its wide geographic distribution, is the oldest and simplest form; Acrotreta
is derived from Acrothele, and is first known toward the close of the Lower Cambrian and
continues through to the Ordovician; from the Acrotreta branch Acrothyra and Discinopsis
diverged in Middle Cambrian time. JLinnarssonella is assumed to have branched off from the
Acrotreta radicle, and it is known to have continued from the central Middle Cambrian to later
Upper Cambrian time. Another branch from <Acrotreta leads to Orbiculoidea in the central
Middle Cambrian, which continues on into the Ordovician. A shell doubtfully identified as
Philthedra occurs in the Middle Cambrian. If correctly identified it represents the Craniidz in
the Cambrian fauna.

Botsfordia is an offshoot from Obolella in the central Lower Cambrian, and I have assumed
it to be the progenitor of Schizopholis of the Middle Cambrian. Qwuebecia of the middle Lower
Cambrian is tentatively shown to be derived from the Obolella radicle.

Another branch is Trematobolus, which is assumed to be the direct progenitor of the Siphon-
otretide as an offshoot of the Obolella primary stock. Yorkia is the first known branch from
Trematobolus in Lower Cambrian time. Dearbornia, as known, is limited to the upper portion

of the Middle Cambrian.
PROTREMATA.

The ancestral types of the true Protremata are, so far as at present known, Nisusia and
Billingsella. These appear to have come from the radicle leading from Micromitra to Kutorgina
of the Lower Cambrian. utorgina is placed on the border line between the Atremata and
Protremata without direct descendants.

Schuchertina (Pl. LI, figs. 6, 6a—m) has a calcareous shell, smooth outer surface, poorly
defined cardinal areas, open delthyrium, and large muscle areas on the ventral valve. It sug-
gests one of the transition forms between Autorgina and Msusia, but as its stratigraphic posi-
tion is in the central Middle Cambrian, far above and much later in time than the early forms
of the lines of descent of the Protremata, it is placed on the border line without descendants.

320 CAMBRIAN BRACHIOPODA.

The earliest representatives of the Nisusiine are Nisusia and its subgenus Jamesella; both
occur in the upper portion of the Lower Cambrian. Nisusia is unknown later than the
upper portion of the Middle Cambrian, and Jamesella is unknown above the base of the Upper
Cambrian. Protorthis, along with its subgenus Loperia, is first known in the central portion
of the Middle Cambrian; it disappears toward the close of the Upper Cambrian. Bullingsella
is known from the central Lower Cambrian and on to nearly the close of the Upper Cambrian.

Of the genera of the Billingsellide other than Billingsella, Wynnia occurs in the Middle
Cambrian. Orusia appears in the upper portion of the Middle Cambrian and continues well
up into the Upper Cambrian, and Otwsia is found in the upper part of the Middle Cambrian.
None of these genera appear to have had descendants in Ordovician time. Wimanella,
although a more primitive form than Billingsella, is not known to occur as low down in the
Lower Cambrian, and its upper range is only to the upper portion of the Middle Cambrian..
It is derived from the Billingsella radicle.

Eoorthis is first known from the lower portion of the Middle Cambrian and continues
through the Upper Cambrian into the Ordovician. Its line of evolution through Bullingsella
appears to have been from the same radicle as Nisusia, which occurs in the upper portion of
the Lower Cambrian. The genus Finkelnburgia is derived from Hoorthis in the lower portion
of the Upper Cambrian. The Ordovician genus Orthis is assumed to have developed from
Eoorthis in late Cambrian time, and Eostrophomena in the early Upper Cambrian.

Syntrophia, beginning in the lower Middle Cambrian, continues into the Ordovician, and
appears to have descendants in Clarkella and in Huenella.

Swantonia suggests the Rhynchonellide in form, but it has a spondylium and it may have
been the progenitor of both Syntrophia and Protorthis. It is represented in the diagram as
an offshoot from the radicle of Nisusia, without descendants. A review of the characters of
the various subgenera of Orthis from the Ordovician strata leads us to expect to find repre-
sentatives of Dinorthis in the Cambrian. According to Hall and Clarke [1892a, p. 195] this
form is characterized by having the ventral valve depressed so that it is flat or concave
over the pallial region, in this respect resembling Hebertella [Hall and Clarke, 1892a, p. 198].
Among Cambrian forms Protorthis (Loperia) dugaldensis (Pl. XCIX, figs. 5, 5a-h) of the
Middle Cambrian has the depressed ventral valve, but otherwise it differs from Danorthis in
having a spondylium in the ventral valve and in the absence of a cardinal process in the dorsal
valve. Thus far there appear to be no representatives of Orthis, Plectorthis, Orthostrophia,
Platystrophia, Heterorthis, Bilobites, Dalmanella, or other Ordovician or Silurian orthoids
among the Cambrian species. In endeavoring to trace a genetic connection between the
Cambrian Billingsellide and the Orthide of the Ordovician we are met at once with the great
hiatus caused by lack of material for study and comparison from the formations between the
Upper Cambrian and the Middle Ordovician. The Orthidz of the Middle Ordovician imclude
a large group of brachiopods, differing radically from the Billmgsellidz in shell structure,
whose ancestral line in the Lower Ordovician and Upper Cambrian is unknown. That this
break will be filled is highly probable, but meantime the more or less conjectural lines of
descent of various authors must be carefully reviewed in each case in connection with all the
stratigraphic and paleontologic evidence afforded by all known Lower Ordovician formations,
especially in the American and European areas. Systematic studies now in progress by
members of the United States Geological Survey may afford much valuable information that
will be of service in this connection.

CAMBRIAN BRACHIOPODA. 321

CLASSIFICATION.

That we may have a graphic illustration to aid in description, the following table and
scheme are inserted. The ordinal classification of Beecher [1891], with emendations, is taken
as the basis for the orders, while the arrangement of superfamilies is practically that of
Schuchert [1897], with such emendations and additions as greater information has rendered
necessary.

Table of classification of Brachiopoda.

Obolella.
(Glyptias).
a | Obolellidz. - . -, Botsfordia.
3 Schizopholis.
S (?)Quebecia.
8 Yorkia.
s Dearbornia.
& Siphonotretide............_... a omopels.
Siphonotreta.
iRistelladzespessecosseeeeeem seen s Rustella. Keyserlingia.
3 2
g te nh = Acrothele.
8 Teale Ei| gj |Actotheline............... (Redlichella).
a (Paterina) s/s us) Discinolepis.
7 (Jeet Oe ee ess apes baacond : ) Blolo
5 (Iphidella). Oo 8 l
2 Volborthi: | S)s Linnarssonella,
oa ree gee S/e)s : Acrotreta.
(?)Helmersenia. Ole & FACTOR eT 2 eRe Pee eee eee Acrothyra.
&
Ourticiidee.............- Sot ra Curticia. A Diseinopsis:
Obolus. g
(Bréggeria). gS
eae & -Discinide..........-- - -Orbiculoidea.
‘ordinia). 9
(Lingulobolus). ia)
= (Mickwitzella).
al. Obolinge cess ee (Acritis). 3
S S (Schmidtia). 3
iS) V i :
Ble eon: 3 Orantidse... 2.42. .deleedecdeh Philhedra.
ang ;
= 5 (Leptembolon). &
<q R (Lingulepis).
Delgadella. Ni
3 isusia.
Silllicamiinses os) Elkania. Nisusiinie’ 22 0-te ee e padeeaa
INeobolimses:S5--25-es25. 55-8 Neobolus. ‘ g ( (Loperia.)
Coil (=
aes a | Wimanella.
ae Bicia. 3) 2
UBTelimee veers ae ne cee { : BY Billingsella.
Dicellomus. S i Billingselline.. eee ee Onusias
. O}e Otusia.
S Ws (aa) Wynnia.
4. #CUIONIMI CEE soe sess scones saaes THO. 2 GOR cS Lae ee es :
‘6 )Schuchertinide..-..-.......-... Schuchertina. a Finkelnburgia.
= aah ee
M4 Slssiee
a ar 2-5 }Rafinesquine............ HKostrophomena.
Bg|5o
DM 4 am=|
2
o 2
g (?)Swantonia.
5 +. Syntrophia.
z Syntrophiide ................ Fencltan
= Clarkella.
®
ay

62667°—vot 51, pr 1—12-—21

322 CAMBRIAN BRACHIOPODA.

Order ATREMATA Beecher [1891, p. 354].
(Emended Schuchert [1897, p. 119] and Walcott [1908e, p. 142].)

Primitive inarticulate corneous or calcareophosphatic Brachiopoda with the pedicle
emerging more or less freely between the two valves. Growth takes place in general around
the anterior and lateral margins. Specialized forms show tendency to develop rudimentary
articulation. Delthyrium originally unmodified, in later genera modified by pseudodeltidia
and pseudochilidia, or by thickened, striated, and more or less furrowed or even cleft vertical
cardinal margins, the ventral cleft in most specialized forms tending to inclose the pedicle and
finally restrict it to the ventral valve; when completely so the genera are referred to the order

Neotremata.
Superfamily RUSTELLACEA Walcott [1908e, p. 143].

Primitive, thick-shelled, corneous or calcareophosphatic Atremata developing more or
less of pseudodeltidia and pseudochilidia.

Family RUSTELLIDZ Walcott [1908e, p. 143).
Primitive Rustellacea with the delthyrium small, open, and not much modified by pseudo-

deltidia or pseudochilidia. Muscle scars and vascular sinuses not well defined in the shell.
Rustella Walcott [1905a, p. 311].

Family PATERINIDZ Schuchert [1893, p. 151].
(Emended Schuchert [1897, p. 119] and Walcott [1908e, p. 143].)

Progressive Rustellacea with the delthyrium more or less closed by pseudodeltidia or
pseudochilidia.
Mickwitzia Schmidt [1888, p. 24].
Micromitra Meek [1873, p. 479].
(Paterina) Beecher [1891, p. 345].
(Iphidella) Walcott [1905a, p. 305).
Volborthia Kutorga [1848, p. 277].
(2) Helmersenia Pander [1861, p. 48].

Superfamily OBOLACEA Schuchert [1896, p. 305].
(Emended Schuchert [1897, p. 119] and Walcott [1908e, p. 143].)

Derived (in Rustellacea), progressive, thick-shelled, caleareophosphatic or corneous Atre-
mata without pseudodeltidia and pseudochilidia. Rounded or linguloid in outline, more or
less lens-shaped, and fixed by a short pedicle throughout life to extraneous objects.

Family CURTICIIDA Walcott and Schuchert [Walcott, 1908e, p. 143].

Primitive Obolacea with a high well-defined delthyrium. Interior characters much as in
Obolidee.
Curticia Walcott [1905a, p. 319].

Family OBOLIDE King [1846].
(Emended Schuchert [1897, p. 119] and Walcott [1908e, p. 143].)

Derived, progressive Obolacea with thickened, striated, vertical cardinal areas traversed
by pedicle grooves. Muscles and vascular trunks strongly impressed in the valves.

Subfamily OBOLINZ: Dall (1870, pp. 154 and 161].
(Emended Walcott [1908e, p. 143].)

Primitive Obolide with the pedicle grooves more or less shallow or deeply rounded, but
never tending to form a sheath or to completely restrict the pedicle opening to the ventral
valve. The radicle of the Trimerellide, by way of the Neoboline, appears to be in this sub-
family in the thick-shelled Middle Cambrian forms of Obolus (s. s.).

;
:

ee

CLASSIFICATION. 323

Obolus Eichwald [1829, p. 274].
(Bréggeria) Walcott [1902, p. 605].
(Palzobolus) Matthew [1895b, p. 201].
(Fordinia) Walcott [1908d, p. 64].
(Lingulobolus) Matthew [1895b, p. 260].
(Mickwitzella) Walcott [1908d, p. 70].
(Aeritis) Volborth [1869, p. 212].
(Schmidtia) Volborth [1869, p. 208].
(Westonia) Walcott [1901, p. 683].

Lingulella Salter [1866b, p. 333].
(Leptembolon) Mickwitz [1896, p. 199].
(ingulepis) Hall [1863, p: 129].

Delgadella Walcott [1908e, pp. 142 and 144].

Subfamily ELKANIINZ Walcott and Schuchert [Walcott, 1908e, p. 144].

Divergent Obolide with posterior or marginal (not central) platforms, to which are attached
the central and outside and middle lateral muscles.
Elkania Ford [1886b, p. 325].

Subfamily NEOBOLINZ Walcott and Schuchert [Walcott 1908e, p. 144].

Progressive Obolide with posterior platforms, to which were probably attached the central
and outside and middle lateral muscles. Subfamily apparently progressive from the Oboline
to the Trimerellidz, though the platform is posterior and not subcentral as in the trimerelloids.

Neobolus Waagen [1885, p. 756].

Subfamily BICIINZ Walcott and Schuchert [Walcott, 1908e, p. 144].

Progressive Obolide with the pedicle restricted to the ventral valve and more or less
inclosed by a pedicle tube, and with rudimentary articulation. The transgressing stock from
the Atremata to the Neotremata (Obolellidz).

Bicia Walcott [1901, p. 676].
Dicellomus Hall [1873, p. 246].

Superfamily KUTORGINACEA Walcott and Schuchert [Walcott, 1908e, p. 144].
Progressive, thick-shelled, almost calcareous atrematous-like shells, tending to be trans-

verse and developing rudimentary articulation, more or less rudimentary cardinal areas, pseu-
dodeltidia, and muscle scars prophetic of the Protremata. Derived out of Rustellacea.

Family KUTORGINID& Schuchert [1893, p. 151).
(Emended Schuchert [1897, p..131] and Walcott [1908e, p. 145].)
Progressive transverse Kutorginacea with rudimentary cardinal areas, great delthyrial
opening, rudimentary articulation, and immature pseudodeltidia. Muscle scars prophetic of the

Strophomenacea.
Kutorgina Billings [1861b, p. 9].

Family SCHUCHERTINIDZ Walcott [1908e, p. 145].

\

Primitive round Kutorgmacea with small cardinal areas. Externally like Odolus, with an
open subtriangular delthyrium which apparently is without a pseudodeltidium. Muscle scars
and vascular markings prophetic, through the Billingsellide, of the Strophomenacea.

Schuchertina Walcott [1905a, p. 323].

Order NEOTREMATA Beecher [1891, p. 354].
(Emended Schuchert [1897, p. 129] and Walcott [1908e, p. 145].)

Derived and specialized inarticulate Brachiopoda (through the Obolide of the Atremata),
as a rule more phosphatic than calcareous, more or less cone-shaped, with the pedicle emerging
during life through a perforation or sheath in the ventral valve, or a triangular more or less

394 CAMBRIAN BRACHIOPODA.

open cleft, or only so in the youngest-shelled stage, after which the ventral valve becomes
attached by a pedicle to foreign objects. Pedicle cleft im derived forms modified by a listrium.
Pseudodeltidia and pseudochilidia as a rule not well developed.

Superfamily SIPHONOTRETACEA Walcott and Schuchert [Walcott, 1908e, p. 145].

Primitive, thick-shelled, calcareous or corneous, oboloid Neotremata, with the pedicle
passing through a ventral sheath, the aperture of which may remain apical and circular in
outline, or it may become elongate through resorption by passing anteriorly through the pro-
tegulum and umbo of the shell. A listrium is not developed. Dorsal protegulum marginal.

Family OBOLELLIDA Walcott and Schuchert [Walcott, 1908e, p. 145].

Primitive Siphonotretacea with the pedicle emerging through a small circular perforation
in the apex of the ventral valve, posterior to the protegulum. Derived out of the Obolide.
Obolella Billings [1861b, p- 7.
(Glyptias) Walcott [1901, p. 675].
Botsfordia Matthew [1891, p. 148].
Schizopholis Waagen [1885, p. 752].
(2) Quebecia Walcott [1905a, p. 320].

Family SIPHONOTRETIDZ Kutorga (1848, p. 253].

(Emended Schuchert [1897, p. 130] and Walcott [1908e, p. 146].)

Progressive Siphonotretacea with the circular or elongate pedicle opening at the apex or
passing by resorption anteriorly through the protegulum and the umbo of the shell.
Yorkia Walcott [1897b, p. 714].
Dearborma Walcott [1908d, p. 78].
Trematobolus Matthew [1893a, p. 276].
Schizambon Walcott [1884b, p. 69].
Siphonotreta de Verneuil [1845, p. 286].
Keyserlingia Pander [1861, p. 46].

Superfamily ACROTRETACEA Schuchert [1896, p. 308].
(Emended Schuchert [1897, p. 129] and Walcott [1908e, p. 146].)

Progressive Neotremata with corneous or calecareocorneous shells. The pedicle opening
is a simple, circular, more or less conspicuous perforation through the apex of the ventral valve.
Dorsal protegulum marginal.

Family ACROTRETIDZ Schuchert [1893, p. 150].

Same characters as superfamily.

Subfamily ACROTHELINZ Walcott and Schuchert [Walcott, 1908e, p. 146].

Depressed large Acrotretide.
Acrothele Linnarsson [1876, p. 20].
(Redlichella) Walcott [1908d, p. 89].
Discinolepis Waagen [1885, p. 749].

Subfamily ACROTRETINZ Matthew [1903, pp. 74 and 91].

Small Acrotretids with more or less high ventral valves.
_ Linnarssonella Walcott [1902, p. 601).
Acrotreta Kuatorga [1848, p. 275].
Acrothyra Matthew [1901b, p. 303].
Discinopsis (Matthew MS.) Hall and Clarke [1892c, p. 105].

a Described as Siphonotretze. b Wrongly credited to Walcott and Schuchert [Walcott, 1908e, p. 146].

:
.
4

CLASSIFICATION. 325

Superfamily DISCINACEA Waagen [1885].
(Emended Schuchert [1897, p. 130] and Walcott [1908e, p. 146].)

Derived Neotremata with phosphatic shells, a listrium modifying the pedicle slit, and
without pseudodeltidia and false cardinal areas. Dorsal protegulum usually subcentral.

Family DISCINIDZ Gray [1840].
(Emended Schuchert [1897, p. 180] and Walcott [1908e, p. 146].)

Discinacea with an open pedicle notch in early life in the posterior margin of the ventral
valve, which is closed posteriorly during neanic growth, leaving a more or less long, narrow
slit partly closed by the listrium.

Orbiculoidea d’Orbigny [1847].

Superfamily CRANIACEA Waagen [1885].
Cemented calcareous specialized Neotremata without pedicle or anal openings at maturity.
Family CRANIIDZ King [1846].

Craniacea with the pedicle functional probably only during nepionic growth.
Philhedra Koken [1889, pp. 465, 467].

Order PROTREMATA Beecher [1891, p. 355].
(Emended Schuchert [1897, p. 131] and Walcott [1908e, p. 147].)

Progressive (though atrematous Kutorginacea), articulate calcareous Brachiopoda with
well-developed cardinal areas. The pedicle opening is restricted to the ventral valve through-
out life or during early growth, and is often modified and more or less closed by a deltidium.
Often there is a chilidium. Brachia unsupported by a calcareous skeleton other than crura.

Superfamily ORTHACEA Walcott and Schuchert [Walcott, 1908e, p. 147].

Derived, progressive Protremata. Cruralia and rudimentary spondylia (pseudospon-
dylia) free or cemented (through sessility) directly to the valves. Sometimes without deltidia
and chilidia. Cardinal process more or less well developed except in the most primitive genera.

Family BILLINGSELLIDZ Schuchert [1893, p. 152].
(Emended Schuchert [1897, p. 132] and Walcott [1908e, p. 147].)

Primitive Orthacea with an open or more or less closed delthyrium. Cardinal process wel!
developed, rudimentary, or absent. Usually with a clearly defined pseudospondylium, to which
the muscles of the ventral valve were attached. Shell structure dense, granular, lamellar,
nonfibrous.

Subfamily NISUSIINZ: Walcott and Schuchert [Walcott, 1908e, p. 147

Primitive Orthacea with more or less well-developed deltidia and with or without rudi-
mentary chilidia. Spondylia and cruralia rudimentary or small and not supported by septa.
Cardinal process rudimentary or absent.

Nisusia Walcott [1905a, p. 247].
(Jamesella) Walcott [1905a, p. 252].

Protorthis Hall and Clarke [1892c, p. 273].
(Loperta) Walcott [1905a, p. 287].

Subfamily BILLINGSELLINZ Walcott [1908e, p. 148].a

Primitive Orthacea very much like Nisusiine, but without true spondylia and cruralia.
There is a more or less well-developed cardinal process except in Lower Cambrian forms.
Wimanella Walcott [1908d, p. 98].
Bullingsella Hall and Clarke [1892b, p. 230].
Orusia Walcott [1905a, p. 273].
Otusia Walcott [1905a, p. 246].
Wynnia Walcott [1908e, pp. 142 and 148).

a This subfamily is wrongly referred to Schuchert, 1893, by Walcott [1908e, p. 148).

326 CAMBRIAN BRACHIOPODA.

Subfamily EOORTHINA Walcott [1908e, p. 148].

Derived Orthacea nearly always with large open delthyria; deltidia and chilidia occasion-
ally retained throughout life, but more often only in the younger-growth stages. Cardinal
process well developed. Shell structure dense, granular, and with punctate lamelle.

Eoorthis Walcott [1908d, p. 102].
Finkelnburgia Walcott [1905a, p. 277].
Superfamily STROPHOMENACEA Schuchert [1896, p. 312].
(Emended Schuchert [1897, p. 131] and Walcott [1908e, p. 148].)
Derived, progressive, terminal Protremata, out of Orthacea (Billingsellide). Deltidia and
chilidia nearly always well developed. Cardinal process always well developed.
Family STROPHOMENIDA King [1846).
Subfamily RAFINESQUINZ Schuchert (1893, p. 153].
(Emended Schuchert [1897, p. 132] and Walcott [1908e, p. 148].)

Strophomenoids having generally a convex ventral and a concave or nearly flat dorsal

valve. :
Hostrophomena Walcott [1905a, p. 256].
Superfamily PENTAMERACEA Schuchert [1896, p. 320].

(Emended Schuchert [1897, p. 134] and Walcott [1908e, p. 148].)

Specialized Protremata with well-developed free or supported spondylia and cruralia.

Deltidia and chilidia usually absent.
Family SYNTROPHIID& Schuchert [1896, p. 320].

(Emended Schuchert [1897, p. 135] and Walcott [1908e, p. 148].)

Primitive Pentameracea with long, straight cardinal areas.
(?) Swantonia Walcott [1905a, p. 296].
Syntrophia Hall and Clarke [1892c, p. 270].
Huenella Walcott [1908d, p. 109].
Clarkella Walcott [1908d, p. 110].

ee

DESCRIPTION OF GENERA AND SPECIES.
Order ATREMATA Beecher.

[e, without; and zpjya, perforation.]

Superfamily RUSTHLLACEA Walcott.
Family RUSTELLID Walcott.
Genus RUSTELLA Walcott.¢

Rustella Waxcorr, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 311. (Mentioned as a new genus, the type species being

described.)
Rustella Waucotr, 1908, Smithsonian Mise. Coll., vol. 53, No. 4, Pl. XI, and pp. 142 and 143. (Classification of genus.)

This genus is founded on Fustella edsoni Walcott. It appears to be the most primitive
form of brachiopod known. The single specimen of Rustella? major (Matthew) does not add
to our knowledge of this genus, and it may belong to some other genus.

The generic name is given in memory of William P. Rust, of Trenton Falls, Oneida County,
New York, whose collections from the Lower Cambrian strata of Georgia, Heaaelin County,
Vermont, were the most extensive and the material the finest obtained there, so far as known

to me.
RustTeLLa EDsSONI Walcott.

( Plate I, figures 1, la-e.

Obolella (Kutorgina) cingulata Brotines (in part), 1861, Geol. Survey Canada, Paleozoic Fossils, vol. 1, p. 8, fig. 9 (not
figs. 8 and 10, which represent specimens of the true Kutorgina cingulata). (Described and discussed as a new |
species. )

Obolella (Kutorgina) engulata Brutrnes (in part), 1861, Report on the Geology of Vermont, vol. 2, p. 948, fig. 348 (not
figs. 347 and 349). (Copy of preceding reference.)

Obolella (Kutorgina) cingulata Brouines (in part), 1862, Report on the Economic Geology of Vermont, by Hager, p. 220,
fig. 348 (not figs. 347 and 349). (Copy, of preceding reference.)

Obolella cingulata Brnuines, 1863, Geol. Survey Canada, Fifteenth Rept. Progress, p.:284, fig. 287c (not figs. 287a and
287b, which represent specimens of the true Kutorgina cingulata and are copied from Billings, 1861b, p. 8, figs.
8 and 10, respectively). (No text reference. Fig. 287c is copied from Billings, 1861b, p. 8, fig. 9.)

Kutorgina cingulata Waxcorr (in part) [not (Bruuines)], 1886, Bull. U. 8. Geol. Survey No. 30, p. 103, Pl. IX, figs. lg
and 1h (not figs. 1, la-f, which represent specimens of the true Kutorgina cingulata). (Specimens now referred
to Rustella edsoni are here mentioned in the discussion of Kutorgina cingulata as representing a possible distinct
species. The specimens represented by figs. lg and 1h are redrawn in this monograph, PI. I, figs. la and 1,
respectively.)

Kutorgina cingulata Waxcort (in part) [not (Brurnes)], 1891, Tenth Ann. Rept. U.S. Geol. Survey, p. 609, Pl. LXIX,
figs. lg and th (not figs. 1, la-f, which represent specimens of the true Kutorgina cingulata). (No text reference.
Figs. 1g and th are copied from figs. 1g and 1h of the preceding reference.)

Rustella edsoni Watcotr, 1905, Proc. U. 8. Nat. Mus., vol. 28, pp. 311-312. (Described and discussed as below as a
new species.)

General form subcircular, biconvex. Ventral valve moderately convex, with the apex at
the margin immediately above a low arch in the posterior margin. Surface smooth except for
concentric growth lines and low ridges that in some shells are quite prominent. A shallow,
broad, rudimentary pedicle groove occurs beneath the apex and on a slightly flattened space
adjoming the posterior margin. Dorsal valve about as convex as the ventral and with the apex
marginal. The interior of the valve shows two rounded depressions beneath the umbo with a
slight, narrow groove between them; a little in advance the outlines of the central muscle
scars occur; rather strong but faintly indicated radiating lines occur toward the front.

a Before Rustella was proposed by Walcott [1905a, p. 311] the species now included under the genus were placed in the following genera:

Obolella ( Kutorgina) Billings [1861b, p. 8; 1861c, p. Obolus Matthew [1890, p. 155].
948; 1862e, p. 220]. Kutorgina Walcott [1891a, p. 609].
Obolella Billings [1863, p. 284]. Mickwitzia Mickwitz [1896, p. 23].

Kutorgina Walcott [1886b, p. 103].

Pe)
to
J

398 ; CAMBRIAN BRACHIOPODA.

Observations.—This shell was identified as the dorsal valve of Kutorgina cingulata by Bill-
ings [1861b, p. 8, fig. 9] and as the ventral valve of the same species by myself [1886b, p. 102,
Pl. IX, figs. 1g and 1h, and 1891a, p. 609, Pl. LXIX, figs. 1g and ih]. They were considered
as distorted, flattened shells. Better material shows them to represent one of the simplest
forms of brachiopod known; with the exception of the rudimentary pedicle furrow and area
there is nothing more than the gaping valve, much like Charles EK. Beecher’s ideal “‘Paterina”’
[1891, p. 345].

The specific name is given in recognition of the excellent work of Mr. George Edson, of
St. Albans, Vermont, in collecting the Lower Paleozoic fossils of that region.

ForMATION AND LOCALITY.—Lower Cambrian: (25)¢ Sandstone just above Parker’s quarry, near Georgia; and (319r)
on the Bullard farm about 2 miles (3.2 km.) east of Swanton; both in Franklin County, Vermont.

(3920) Arenaceous limestone collected somewhere in Vermont (exact location unknown).

(49) Sandstone on Codorus Creek, 0.125 mile (0.2 km.) below Meyer’s mill, near Hmigsville; and (49a) sand-
stone on the Liverpool road, south of the schoolhouse, 3 miles (4.8 km.) northwest of York; both in York County,
Pennsylvania. :

RusreLLa? magor (Matthew).

Text figure 19.

Obolus ? major MatrHEw, 1890, Trans. Roy. Soc: Canada for 1889, Ist ser., vol. 7, sec. 4, No. 12, p. 155, Pl. VIII, fig. 3.
(Described and discussed as a new species; see below for copy of description. The specimen represented by
fig. 3 is redrawn below, fig. 19.)

Mickwitzia ? major (Matthew), Mickwirz, 1896, Mém. Acad. imp. sci. St.-Pétersbourg, 8th ser., vol. 4, No. 2, p. 23.
(Discussed in German.)

The original description by Matthew follows:

Only the dorsal valve known. This is transversely oval, flattened near the umbo,
and deep within the edges toward the back of the shell.

The interior markings seem those of an Obolus. The median line is strongly marked
just within the umbo, and at the middle of the shell, in front of which it appears to fork.
The scars of the posterior laterals only are distinct.

NY A

Ficure 19.—Rustella? major
(Matthew). A, A’, Cast froma
natural mold in sandstone;
side outline restored. From
Locality 301v, Lower Cam-
brian shales on Hanford

Brook, New Brunswick. ~

The original mold is in the
collections of the University
of Toronto. The cast from
which the figure was drawn is
in the collections of the U. S.
National Museum, Cat. No.
51462. This specimen was
figured by Matthew [1890, Pl.
~ VIII, fig. 3].

The example known shows the interior of the shell and a little of the external surface.
The shell was thin, and is changed to iron oxide. The outer surface near the edge of the
shell was covered by fine radiating lines or ridges. ;

Observations.—The type and only specimen of this form is preserved
as a natural mold in an impure sandstone; the original shell had been
removed, and the resulting mold is very similar to those of Rustella
edsoni (PI. I, figs. 1 and 1a) from a fine-grained sandstone; in the case
of the latter species only a film remains to indicate the original shell, while
in the calcareous nodules embedded in the sandstone the shell is shown
to be of considerable thickness.

The reference to the genus Rustella is based on the similarity in
size and form between this species and Rustella edsont and the fact that

Rustella? major occurs at about the same stratigraphic horizon in the Lower Cambrian as fh.
edsoni and below the recognized Middle Cambrian fauna. At the same locality and at about
the same horizon I found several Lower Cambrian fossils: Micromitra (Paterina) labradorica,
Hyolithes cf. communis, Coleoloides cf. typrealis [Walcott, 1900, p. 322].

ForMATION AND LOCALITY.—Lower Cambrian: (301v [Matthew, 1890, p. 155]) Sandy shales of Division 2b of the
“Basal series” of Matthew, on Hanford Brook, St. John County, New Brunswick, Canada.

a The type locality is in italics; where there is but one locality, however, this will not be italicized. When a locality is not represented in
the collections of the United States National Museum, the authority for its citation is given immediately after the locality number, or at the end of
the paragraph, if several can be grouped under the one reference.

CAMBRIAN BRACHIOPODA. 329

Family PATERINID4 Schuchert.

Genus MICKWITZIA Schmidt.

Mickwitzia Scumipr, 1888, Mém. Acad. imp. sci. St.-Pétersbourg, 7th ser., vol. 36, No. 2, p. 24. (Described in German
as a new genus.)

Mickwitzia Schmidt, Hatt and Crarxke, 1892, Eleventh Ann. Rept. State Geologist New York for 1891, p. 246. (De-
scribed.

Mickuntzia canes Hawt and Crarke, 1892, Forty-fiith Ann. Rept. New York State Museum for 1891, p. 562. (Copy
of preceding reference.)

Mickwitzia Schmidt, Hatt and Crarks, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, pp. 86-87. (Described
and discussed.)

Causea Wrtan, 1902, Bull. Geol. Inst. Univ. Upsala, vol. 6, pt. 1, No. 11, pp. 53-54. (Described and discussed in

German as a new genus, the description being incorporated with that of the type species, Cawsea formosa.)
Mickwitazia Schmidt, Waxcott, 1908, Smithsonian Misc. Coll., vol. 53, No. 4, Pl. XI, and pp. 142 and 148. (Classifica-

tion of genus.)

Shell large, unequivalve. Ovate or subcircular, with apex of valves within the margin
and erect, or curved over the margin. A false cardinal area may or may not be obscurely defined;
valves not articulated. Shell substance mostly calcium phosphate and arranged in three prin-
cipal layers. The outer layer is papillose, with fine and large puncte; middle layer marked
by numerous radiating and concentric, more or less elevated lines and small puncte that become
very numerous toward the front margins of the shell; inner layer marked by large puncte or
vertical canals and often a thickening of shell substance that takes the form of irregular ser-
pentine ridges penetrated by vertical canals.

Type.—Lingula? monilifera Linnarsson.

Observations —Both Schmidt [1888, p. 24] and Hall and Clarke [1892c, pp. 86-87] define
and discuss this genus, but with the new material I have for study, a new diagnosis has been
prepared. The genus appears to fall within the order Atremata Beecher [1891, p. 354] and
the family Patermidee Schuchert [1897, p. 119]. The latter family has heretofore included
only the genus Micromitra. The species of Mickwitzia include chitimous or phosphatic shells
with elevated ventral valve, having an apex elevated within the margin ( Mickwitzia formosa
(Wiman)), or arching over ‘ine margin (Mickwitera monilifera (@anmanscen)): Micromitra has a
clearly marked area and pseudodeltidium, in this respect being further advanced in evolution
than Mickwitzia. A series of shells of Mickwitzia might show a more strongly marked false
area in the young shell than im the adult forms.

The generic name was given in honor of Dr. A. Mickwitz.

MickwitziA FORMOSA (Wiman).

5 Plate VI, figures 3, 3a-c.

Causea formosa WimAN, 1902, Bull. Geol. Inst. Univ. Upsala, vol. 6, pt. 1, No. 11, pp. 53-54, Pl. II, figs. 1-5. (De-
scribed and dserne sea in German as a new species. The specimen represented by fis 1-5 is redrawn in this
monograph, Pl. VI, figs. 3, 3a-c.)

Outline of ventral valve circular; apex a little in front of the posterior margin, strongly
elevated, and rising vertically above a broad, obscurely defined false area. The area is defined
by a rounded angle where the transverse, slightly convex posterior surface below the apex
unites with the lateral slopes from the apex. The posterior margin is slightly arched, so as
to form an opening between it and the dorsal valve.

Only the inner layers of the shell are preserved on the type specimen, the outer epidermal
layer having been exfoliated. On the posterior portion of the shell the second or middle layer
has the radiating and concentric lines typical of Mickwitzia monilifera (Linnarsson). Toward
the front the layer of shell is marked by faint radiating lines and many fine puncte, exactly
as in specimens of M. monilifera, where the outer layer is exfoliated. This type of surface is

a Prior to the definition of Mickwitzia by Schmidt [1888, p. 24], the species now referred to this genus were placed under the following genera:
Lingula Linnarsson [1869a, p. 344; 1869b, p. 398]. Obolus Linnarsson [1871, pp. 9-10].

330 CAMBRIAN BRACHIOPODA. »

shown by Plate VI, figure 1k, except that the puncte are very few on the center of the shell,
which is the part enlarged by the figure. The inner layer of shell of I. formosa has numerous
large puncte that penetrate it, and also the irregular serpentine ridged shell deposits charac-
teristic of this species and of many adult shells of M. monilifera.

Observations—Wiman [1902, p. 53] created the genus Causea to receive this species. He
very kindly sent me the type material for study, and with it a fine collection of M. monilifera
(Linnarsson). I am unable to determine generic distinctions between the two species. The
shell substance and structure are the same, so far as material exists for comparison. Mickwitzia
formosa has a more elevated apex and is a much larger shell, but these are specific rather than
generic distinctions.

FoRMATION AND LOCALITY.—Middle? Cambrian: (3111 [Wiman, 1902, p. 57]) Drift bowlder of bluish calcareous
sandstone, No. 31, on Biludden, about 20 miles (32.2 km.) east of Gefle, Province of Gefleborg, Sweden.

(811s [Wiman, 1902, p. 57]) Drift bowlder of gray quartzitic sandstone, at Skarpnaté, Aland Island, Finland,
Russia. :

MickKWITzIA MONILIFERA (Linnarsson).
Plate VI, figures 1, la—p; Plate LIX, figure 2.

Lingula? monilifera Linnarsson, 1869, Ofversigt af K. svensk. Vet.-Akad. Férhandl. for 1869, Bd. 26, No. 3, p. 344,
Pl. VII, figs. 1 and 2. (Described and discussed in Swedish as a new species.)

Lingula monilifera LinnaRrsson, 1869, Geol. Mag., vol. 6, p. 398, Pl. XI, figs. land2. (Text translated into English from
Linnarsson, 1869a, p. 344. Figs. 1 and 2 are copied from Linnarsson, 1869a, Pl. VII, figs. 1 and 2.)

Obolus? monilifer Linnarsson, 1871, Bihang till K. svensk. Vet.-Akad. Handi., Bd. 9, No. 7, pp. 9-10, Pl. I, figs.
2 and 3. (Described and discussed in Swedish.)

Mickwitzia monilifera (Linnarsson), ScumiptT, 1888, Mém. Acad. imp. sci. St.-Pétersbourg, 7th ser., vol. 36, No. 2,
pp. 21-23 and 24-25, Pl. II, figs. 6-26. (Described and discussed in German. Figs. 12c and 12d are copied
in this monograph, Pl. VI, figs. lp and 1o, respectively.)

Mickwitzia monilifera (Linnarsson), WaLcotr, 1891, Tenth Ann. Rept. U. 8. Geol. Survey, Pl. LXX, figs. 2, 2a-h.
(No text reference. Figs. 2, 2a-f are copied from Schmidt, 1888, Pl. II, figs. 16a, 16c, 16b, 12b, 12c, 12d, and
12a, respectively. Fig. 2h is copied from Linnarsson, 1871, PI. I, fig. 2.)

Mickwitzia monilifera (Linnarsson), Hatt and CLARKE, 1892, Eleventh Ann. Rept. State Geologist New York for
1891, figs. 253-255, p. 246. (No text references. Figs. 253-259 are copied from Schmidt, 1888, Pl. II, figs. 14a,
8b, and 16b, respectively.)

Mickwitzia monilifera (Linnarsson), Hani and CLarke, 1892, Forty-fifth Ann. Rept. New York State Museum for 1891,
figs. 253-255, p. 562. (Copy of preceding reference.)

Mickwitzia monilifera (Linnarsson), Haun and CrarKe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, p. 86,
figs. 42-44. (No text reference. Figs. 42-44 are aanted from Schmidt, 1888, Pl. II, figs. 14a, 8b, ia 16b,
respectively.) ;

Mickwitzia monilifera (Linnarsson), Wrman, 1902, Bull. Geol. Inst. Univ. Upsala, vol. 6, pt. 1, No. 11, p. 53, Pl. IT,
figs. 12-14, Pl. IV, figs. 2and 3. (Characterized and discussed in German.)

General form ovate to subcircular; biconvex or subplanoconvex.
Surface of exterior of the shell papillose; each papilla is about as high as the width of
its base, and the apex is perforated by a minute tube. There appears to be no systematic

arrangement of the papille; they are thickly set over the entire surface of a dorsal valve 20 mm.

in diameter; on some parts of the shell the papille are closely arranged in undulating, irregular
ridges; these, when worn by attrition, have the appearance shown by Plate VI, figureim. This
outer surface is rarely preserved, as it usually adheres to the matrix, leaving the second layer
exposed to view. The layer of shell immediately beneath the outer shell is marked by concentric,
elevated, minutely undulating, raised, closely set lines that are crossed by fine, radiating, closely
set raised lines (Pl. VI, figs. 1k and 11); this is the surface illustrated by Linnarsson [1869b,
Pl. XI, fig. 2] and Schmidt [1888, Pl. II, fig. 21]; it is seen on most specimens preserving the
shell. T fe distance from the apex, enictiilain of preservation, etc., cause great variation in the
appearance of the inner layer. Scattered puncte penetrate the inner layer, and often the
depressions between the concentric and radiating raised lines give the surface a finely and
regularly pitted or punctate appearance. On some shells the punctz are numerous and regu-
larly arranged toward the front of the shell. The inner surface of the inner layer of the shell
is marked by strong puncte in adult shells. Frequently a shell deposit is found over the inner

PATERINID. 331

surface which is punctate and curiously ridged, very much like the outer surface in partly worn
shells. (See Pl. VI, fig. 1m, of the outer surface.)

Substance of shell mostly calcium phosphate [Schmidt, 1888, p. 23]. The shell is thick in
small shells, but does not increase proportionately in thickness with age.

The largest shell in the collection before me has a length of 32 mm., exclusive of extension
of apex over area; width 30 mm.

Ventral valve convex, with apex projecting a little over the posterior margin. A false area
is more or less definitely outlined; in some specimens it is quite clear and in others very indefi-
nite ; it is much like some of the less clearly defined false areas of species of Micromitra. When
well defined the posterior margin of the valve arches slightly, as in Plate VI, figure le.

Dorsal valve slightly convex, with a very low submarginal apex. The interior of the valve
is usually without traces of muscular or vascular markings. In one worn shell a median sinus
occurs, and what appears to be the path of advance of the anterolateral muscle scars (Pl. VI,
fig. 1f); another unworn shell shows a trace of radiating lines near the median line; and a third
has two plainly marked muscle scars a little in advance of the apex and some distance from the
median line; these occupy the position of the posterior muscle scars as they occur in the dorsal
valve of Schizocrania.

Observations.—The preceding description is based on specimens in the collection of the
United States National Museum. Mr. Schmalensee, a collector in the Geological Survey of
Sweden, at my request collected a number of fine specimens for the United States National
Museum. ‘The museum has also received a number of casts from other sources.

Schmidt [1888, p. 22] describes a hooked process as occurring in a cast of a dorsal valve.
After noting his expression of doubt as to whether the process belonged to the shell, and also
after a study of the interiors of finely preserved dorsal valves, I can not retain the view that
such a process exists in the dorsal valve of this species. We may attribute the apparent occur-
rence of it in the cast studied by Schmidt to the accidental attachment of some foreign body,
or it may be that the cast belongs to some other genus and species.

There is no other species of the genus that is closely related to Mickwitzva monilifera; M.
formosa has the same general character of shell, but its ventral valve is more erect, much larger,
and it differs a little in the details of the surfaces of the interior layers of the shell.

FoRMATION AND LOCALITY.—Middle? Cambrian: (3111 [Wiman, 1902, p. 57]) Drift bowlder of bluish calcareous
sandstone, No. 31, on Biludden, about 20 miles (32.2 km.) east of Gefle, Province of Gefleborg; and (311u [Wiman,
1902, p. 57]) drift bowlder of blue calcareous sandstone, Séderarm lighthouse, near Norrtelje, Province of Stockholm;
both in Sweden.

(811e) Drift bowlder of rusty sandstone, south of Lumparn, parish of Jomala; (811f) drift bowlder of gray quartz-
itic sandstone, at Slemmern, Mariehamn; (311q) drift bowlder of gray quartzitic sandstone, at Ytternaiset, Mariehamn;
and (811r) drift bowlder of gray quartzitic sandstone, at Granboda, Lemland; all [Wiman, 1902, p. 57] on Aland Island,
Finland, Russia.

Lower Cambrian: (390j) Hophyton sandstone at Lugnds, 8 miles (12 km.) south-southwest of Mariestad, Province
of Skaraborg; and (390k) Hophyton sandstone at Prestorp, north of the hill of Billingen, Province of Skaraborg; both
in Sweden.

(896q) Upper boundary of the blue clay with the Fucoid sandstone, the ‘‘ Mickwitzia conglomerate” at Reval;
(396r) in the ‘‘upper strata” at Streitberg, near Reval; (396s) in loose blocks on Kosch Brook near Likkat, near Reval;
(396t) at the sandstone capes of Ziegelskoppel, Kakkomaggi (also Rocca al Mare), near Reval; (396u) in loose blocks
on the lower course of Jaggowal Brook, about 20 miles (32.2 km.) east-southeast of Reval; (896v) at the upper boundary
of a dolomitic sandstone with which the Olenellus stratum begins, below the cement factory on Kunda Brook;¢ and
(396w) in the glauconitic sands above the main mass of the clay, below the cement factory on Kunda Brook; all [Schmidt,
1888, p. 24] in the Government of Esthonia, Russia.

Mickxwirzia occrpens Walcott.
Plate VI, figure 4.
Mickwitzia occidens Watcott, 1908, Smithsonian Misc. Coll., vol. 8, No. 3, p. 54, Pl. VII, fig. 1. (Described as below
as anew species. Fig. 1 is copied in this monograph, Pl. VI, fig. 4.)
Only crushed and broken specimens of this shell are available. One of these shows that
the apex of the ventral valve was a little above the posterior margin of the shell, very much as

Uv

@ Specimens of this species from the locality on Kunda Brook are included in the collections of the United States National Museum.

332 CAMBRIAN BRACHIOPODA.

in Mickwitzia pretiosa Walcott. The outline of the valves appears to have been ovate to sub-
circular and the ventral valve moderately convex. The shell is phosphatic or chitinous and
built up of three principal layers. The outer layer is thin, and thickly set with minute pustules
or granules that give the surface a roughened appearance. When the outer layer is exfoliated,
which is usually the case, the middle layer presents a smooth, shining surface that is marked
by a few concentric striz and numerous fine radiating strize, between which many minute puncte
occur. The inner layer shows minute, irregular, serpentine, rounded ridges, perforated by
vertical canals or puncte. An interior of a ventral valve shows: the lines of advance of the
anterolateral muscle scars. The largest shell imdicated on the surface of the siliceous shale
has a length and width of 12 mm.

The generic reference of this species is based on the apex of the ventral valve and the
structure and character of the shell.

FoRMATION AND LocaLmy.—Lower Cambrian: (53) Sandstones in the lower portion of 3d of the Waucoba Springs
section [Walcott, 1908f, pp. 187 and 188], 1 mile (1.6 km.) east of the Saline Valley road, about 2.5 miles (4 km.) east-
northeast of Waucoba Springs, Inyo County, California.

(174c) Sandstones on small hill in the salt flat, 1 mile (1.6 km.) northeast of Silver Peak Mill, Silver Peak quad-
rangle(U. S. Geol. Survey), Esmeralda County, Nevada.

MicKwitzia PRETIOSA Walcott.
Plate VI, figure 2. i {
Mickwitzia pretiosa Watcott, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, pp. 54-55, Pl. VII, fig. 2. (Described and

discussed as below as a new species. Fig. 2 is copied in this monograph, Pl. VI, fig. 2.)

This species is founded on a single specimen of a ventral valve. It has a length of 7mm.,
width 6.5 mm. Outliae subcireular, slightly convex; apex curved over toward the posterior
margin and projecting beyond it. False area short and obscure. Surface marked by radiating.
raised lines that at the front margin show six in a distance of 2 millimeters. Fine papille are
thickly scattered over the surface, with a tendency to follow concentric lines of growth on some |
portions of the shell, and on others they appear on low, narrow, serpentine ridges, as in I.
monilifera (Linnarsson). A few large puncte are scattered here and there over the surface.
_ Inner surfaces and layers of shell unknown.

This beautiful shell differs in the details of its surface from IM. monilifera; it is also less
convex, and the apex is nearer the posterior margin.

ForMATION AND LOCALITY.—Lower Cambrian: (390j) Hophyton sandstone at Lugnas, 8 miles (12.8 km.) south-
southwest of Mariestad, Province of Skaraborg, Sweden.

Mickwirzia? sp. undt.
Lingula hawkei ? Bornemann [not Rovavtt], 1891, Nova Acta Acad. Czes. Leop.-Carol. Germanice Naturze Curidsorum,

Bd. 56, No. 3, p. 439, Pl. XIX, figs. 19-20. (Characterized and discussed in German.)

Bornemann describes and illustrates some large shells 3 centimeters or more in diameter
from the Olenopsis beds, which he states are characterized by a somewhat quadrangular outline
and faint sinus and resemble Barrande’s ‘‘Lingula feistmanteli.”” I am inclined to compare
this form with the large compressed casts of Mickwitzia monilifera and to make a tentative
reference to the genus Mickwitzia. The shell is certainly not Lingula rouaulti Salter.

FoRMATION AND LOCALITY.—Middle? Cambrian: (354a [Bornemann, 1891, p. 439]) in grayish-white quartzitic
sandstones in the valley of Gutturu Sartu, island of Sardinia, Italy.

Genus MICROMITRA Meek.@
[uexodc, Small; and mitra, a hat.]
Not Iphidea Baty, 1865, Entom. Monthly Magazine, vol. 2, p. 127. (Proposed for a genus of Coleoptera.)
Iphidea Bruunes [not Baty], 1872, Canadian Naturalist, 2d ser., vol. 6, No. 4, pp. 477-478. (Type species (“‘Iphidea
bella”) described and discussed and “‘ [phidea” mentioned as a new genus. The reference is copied in this mono-
graph under Micromitra (Paterina) bella, p. 345.)

a The synonymy for this genus does not give a complete record of the various genera under which the species now included in Micromitra were
formerly placed; it includes only those references in which the genus is discussed or described. For the sake of completing the record the remaining
mere generic references are here listed:

Kutorgina Linnarsson [1876, p. 25]. Kutorgina Matley [1902, p. 146].
Kutorgina Hall and Whitfield [1877, p. 207). Kutorgina Grénwall [1902, p. 40).
Kutorgina Walcott [1884b, p. 20].

eee

PATERINIDA. 3990

Micromitra MrexEx, 1873, Sixth Ann. Rept. U.S. Geol. and Geog. Survey Terr. for 1872, p.479. (Suggests Micromitra as
anew generic name for ‘‘ [phidea (2?) sculptilis” if that species should prove to belong to a new genus. Thisrefer-
ence is quoted in this monograph, p. 334.)

Iphidea Bitrines, 1874, Geol. Survey Canada, Paleozoic Fossils, vol. 2, pt. 1, p. 76. (Copied from Billings, 1872b,
pp. 477-478.)

Iphidea Billings, Linnarsson, 1876, Bihang till K. svensk. Vet.-Akad. Handl., Bd. 3, No. 12, p. 26. (Mentioned in
English in the discussion of ‘‘ Iphidea ornatella.’’) i

Iphidea Billings, Datt, 1877, Bull. U. S. Nat. Mus., No. 8, p. 39. (Mentioned.)

Iphidea Billings, Waucort, 1886, Bull. U. S. Geol. Survey No. 30, pp. 100-101. (Copies the original description, Bil-
lings, 1872b, pp. 477-478, of the type species (‘‘Iphidea bella”’) and discusses genus.)

Kutorgina Waxcorr (in part), [not Bmines], 1886, Idem, pp. 101-102. (Genus Kutorgina described, but descrip-
tion also includes reference to sigeeanoas now referred to Micromitra, Micromitra (Paterina), and Micromitra
(LIphidelia).)

Iphidea Billings, OnHieRT, 1887, Manuel de conchyliologie, by Fischer, p. 1270. (Described in French.)

?Iphidea Billings, Hatt and CLaRKke (in part), 1892, Eleventh Ann. Rept. State Geologist New York for 1891, p. 249
(Described, but accompanied by figures of specimens belonging with the subgenus Paterina.)

?Iphidea Billings, Haun and CLarKeE (in part), 1892, Forty-fiith Ann. Rept. New York State Mus. for 1891, p. 565
(Copy of preceding reference.)

Kutorgina Walcott, Haut and CLARKE (in part), 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, pp. 90-94
(Copies Walcott’s description, 1886b, pp. 101-102, and discusses genus, but description and discussion also
include reference to specimens now referred to Micromitra, Micromitra (Paterina), Micromitra (Iphidella), Pro-
torthis, and Billingsella.)

Iphidea Billings, Haut and CrarKe, 1892, idem, pp. 97-98. (Copies the original description, Billings, 1872b, pp.
477-A78, of the type species (‘‘Iphidea bella”) and discusses genus.)

Iphidea Billings, Waucort (in part), 1897, Proc. U.S. Nat. Mus., vol. 19, pp. 707-711. (Discussed. The genus includes
species now referred to Micromitra, Micromitra (Paterina), and Micromitra (Iphidella).)

Iphidea Billings, ScHucH=ErRT (in part), 1897, Bull. U. 8. Geol. Survey No. 87, p. 233. (Merely refers Micromitra and
Paterina to Iphidea.)

Iphidea Billings, Waucorr, 1899, Mon. U. 8. Geol. Survey, vol. 32, pt. 2, pp. 447-448. (Mentioned in discussion of

“*Tphidea sculptilis.’’)

Iphidella Waucorr (in part), 1905, Proc. U. S. Nat. Mus., vol. 28, p. 304. (Merely proposed to replace Iphidea, but
includes reference to specimens belonging with Micromitra, Micromitra (Paterina), and Micromitra (Iphidelia).)

Paterina (Micromitra) (Meek), ScoucHErT, 1905, Am. Jour. Sci., 4th ser., vol. 19, p. 329. (Suggests that Micromitra
be used in a subgeneric sense, under Paterina, for the forms typified by Micromitra sculptilis.)

Not Iphidea Grapav and Summer, 1907, North American Index Fossils, vol. 1, p. 201. (Described, but the species
placed under it belong with the subgenera Paterina and Iphidelia.)

Micromitra Meek, Watcort, 1908, Smithsonian Misc. Coll., vol. 53, No. 4, Pl. XI, and pp. 142 and 148. (Classification
of genus.)

Ventral valve conical (Micromitra (Paterina) etheridgei (Tate), Pl. III, fig. 10) to depressed
conical (MM. (P.) labradorica (Billings), Pl. II, fig. 2), with the beak curving more or less over a
false area which is divided midway by a triangular fissure that may be covered almost entirely
(M. (P.) superba (Walcott), Pl. II, fig. 1) or only in part (Micromitra (Iphidella) ornatella (Lin-
narsson), Pl. III, fig. 6) by a convex pseudodeltidium.

Dorsal valve slightly to moderately convex. Beak small and usually curved a little over
a low area ( Micromitra pealer (Walcott), Pl. III, fig. 3e’) that has a rather broad pseudodeltidium.

Surface marked by concentric lines of growth and fine radiating strie (Micromitra (Paterina)
labradorica (Billings)); crenulated concentric striz that give a more or less distinctly crenu-
lated appearance to the surface (Micromitra sculptilis (Meek)); and strongly crenulated concen-
tric striz forming a network of raised, obliquely arranged lines that divide the surface into
minute pits (Micromitra (Iphidella) pannula (White)).

Shell substance corneous. Shell built up of thin layers or lamellz that are more or less
oblique to the outer surface. :

Very little is known of the interior of the valves. The ventral valve of Micromitra (Pater-
aa) labradorica (Billings) (Pl. II, fig. 2c) has a few lines or ridges that radiate from the beak
very much as in Kutorgina (PI. V, fig. 1). The dorsal valve also shows radiating ridges (Micro-
mitra (Iphidella) ornatella (Linnarsson) PI. III, fig. 6d), and in addition an exfoliated shell of
M. (1.) pannula ophirensis Walcott shows a median ridge, the base of the main vascular sinuses,
and two central muscle scars (Pl. IV, fig. 4e).

Type.—Iphidea (2?) sculptilis Meek [1873, p. 479].

334 CAMBRIAN BRACHIOPODA.

Meek’s original reference to Micromitra [1873, p. 479] is as follows:

It is quite probable that when specimens showing clearly all the characters of this shell can be examined it will
be found to belong to an undefined genus, either of the Brachiopoda or some other group. In this case I would propose
for this genus the name Micromitra.

The type specimen labeled by Meek in 1873 as [phidea ( Micromitra) sculptilis is in the col-
lections of the United States National Museum (Catalogue No. 7864). The label is in Meek’s
handwriting and firmly attached to the specimen of rock containing the shell.

The description of the shell referred to [phidea (??) sculptilis Meek [1873, p. 479] is that of
the ventral valve. While no generic description is given and the specific description is Imcom-
plete, we are necessitated by the present rules of nomenclature to accept the name Micromitra,
since [phidea, as proposed by Billings [1872b, p. 477], was preoccupied by Baly in 1865.

When away, engaged in field work, I accidentally discovered that the genus Iphidea was
first used by Baly in 1865. I then put the name /phidella in some manuscript notes and by
oversight this name was published [Walcott, 1905a, p. 304]. Schuchert [1905, p. 329] called
attention to its bemg a synonym of Micromitra and Paterna. This is shown in my synonymy
of the genus [phidea [1897b, p. 707]. I now use [phidella as a subgenus of Micromitra.

Billings’s description of the genus [phidea and that of the type species were combined. At
the time of my study of Kutorgina and Iphidea [Walcott, 1886b, p. 100] I did not agree with
Billings in his reference of “‘Obolus labradoricus” to Iphidea [Billings, 1874, p. 76]. Since that
time I have ‘collected more material representing this group of shells, and from its study have
come to the conclusion that Billings was correct im referring ‘‘O. labradoricus” to his genus
Iphidea. The ventral valve of ‘0. labradoricus” has a narrow false area of the same type as
Micromitra (Paterina) bella (Billings), and the characteristic pseudodeltidium is clearly shown
in a section, and it is known to occur in Micromitra sculptilis (Meek), Micromitra ([phidella)
ornatella (Linnarsson), and M. (7.) pannula (White). The extreme development of the false
area and pseudodeltidium is found in WM. (P.) superba (Walcott), from the Middle Cambrian
- “Tonto” sandstone of the Grand Canyon of the Colorado. In this form the ventral valve is
broadly conical, and the large pseudodeltidium projects backward at an angle equal to the slope
from the apex to the front. In Micromitra (Paterina) bella the false area slopes more abruptly
downward and in Micromitra (Iphidella) ornatella it is nearly vertical, the pseudodeltidium being
much shorter and projecting but a short distance beyond the area. Theslope of the area of M. (J.)
ornatella is essentially the same as that of Micromitra (Paterina) labradorica swantonensis (Wal-
cott), which is the type of Beecher’s genus Paterina. (See p. 344.) In some specimens of the
latter species the beak projects so that the slope of the area carries it forward to a considerable
distance under the beak. This is also true of Micromitra (Iphidella) pannula.

The presence of an apical foramen in Micromitra (Paterina) bella and Micromitra (Iphidella)
ornatella would separate those species from the Paterinide, but from a careful study of all the
evidence attainable I am led to question the presence of a true apical foramen in either species.
Unless there are other characters than those shown by the false area and pseudodeltidium and
the angle at which they slope, it will be impracticable to generically separate Micromitra (Pater-
ina) bella and M. (P.) labradorica and the other species mentioned.

In his original description, Billings [1872b, p. 478] says:

Tn the specimen above figured there is an aperture in the beak, but in another there is no appearanc? whatever
of a pertoration.

In a fine series of Micromitra (Paterina) bella from the Lower Cambrian, south of Hmigs-
ville, York County, Pennsylvania, the characteristics of the genus and species are strikingly
well shown. In none of the specimens is there in the ventral valve an indication of an apical
pedicle opening. The dorsal valve is slightly elevated, and m the half-dozen well-preserved
specimens no trace has been observed of any false area or pseudodeltidium; but in Micromitra
(Iphidella) pannula the false area is even more clearly defined than in the ventral valve, and
the pseudodeltidium is present as a depressed concave covering of more than one-half of the
triangular space inside the narrow area on each side. The area on the dorsal valve has also
been observed in M. (J.) ornatella (Linnarsson) and Micromitra (Paterina) labradorica (Billings).

r
-

tm” gee Te tote pe eee 4 ee eee

PATERINIDZ. 335

Linnarsson [1876, p. 25], in describing Micromitra (Iphidella) ornatella, speaks of the pres-
ence of a minute foramen; but, after the study of several finely preserved ventral valves from
the Paradoxides beds of Andrarum, Sweden, I am led to believe that what he considered to be an
apical foramen is a depression in the apex of the shell on the incurved beak which was present
in one of the embryonic (nepionic) stages and was subsequently lost. This would involve the
crowding out, as it were, of the pedicle posteriorly, the only evidence of its presence in the
adult being the narrow, slightly depressed slit at the apex of the valve in some specimens. The
pedicle in the adult shell is protruded between the two valves and separated from the scar of
the embryonic pedicle slit by the growth of a pseudodeltidium.

The examination of the somewhat closely allied form, Micromitra (Iphidella) pannula
(White), shows the presence in some specimens of an apical depression, and its absence in
others. In Micromitra (Paterina) superba (Walcott), still more closely approaching the type,
M. (P.) bella (Billings), in external appearance, there is no trace of an apical slit. In Micromitra
(Paterina) crenistria (Walcott), which is associated with MW. (P.) swperba, the apex is rounded, while
in the somewhat similar but distinct form, MM. pealei (Walcott), from the Gallatin River valley of
Montana, the apical slit is as clearly shown as in Micromitra (Iphidella) ornatella (Linnarsson),
but there is no apical foramen.

Hall and Clarke [1892c, p. 97] illustrate a specimen of Micromitra (Paterina) bella showing
an apical foramen, but in the description of PI. IV, fig. 8, the statement is made that the foramen
is not altogether distinct in the specimen.

The systematic position of the genus Micromitra appears to be in the Atremata of Beecher
[1891, p. 354], with possible characters that nearly place it in the Protremata. The presence
of an obscure apical furrow in front of the apex of Micromitra (Paterina) bella (Billings), Micro-
mitra ([phidella) ornatella (Linnarsson), and in some specimens of Micromitra pealei (Walcott)
tends to support the view that the pedicle was apical in its early stages. We also have to con-
sider the area of what appears to be the dorsal valve of Micromitra (Iphidella) pannula. In
this species there is a rather deep convex pseudodeltidium in the conical valve and a clearly
defined, depressed pseudodeltidium on the flat valve between the sides of the narrow false
area. There is also present on the latter valve a narrow median groove extending from the
apex to the posterior margin of the pseudodeltidium; it is similar in appearance to the pedicle
groove of the ventral valve of Obolus and Rhinobolus. This suggests that the flat valve may be
the pedicle valve, but the presence of a scar of the embryo pedicle opening on the conical valve
- is opposed to such an interpretation.

It may be urged that Micromitra is a true atrematous genus, the pedicle never having been
inclosed and the slit on the ventral valve being only a depression without special significance.
This may be so, but the impression it conveys to me is that the slit indicates a pedicle opening
which existed near the apex of the ventral valve at an early stage in its growth, but which was
subsequently closed, the pedicle continuing to protrude between the valves.

Whiteaves wrote me, under date of July 23, 1896, that with the exception of the specimen
which is referred in this monograph to Micromitra (Paterina) logani (see pp. 345 and 350),
there were no specimens or electrotypes of the types of Micromitra (Paterina) bella (Billings) in
the collections of the Geological Survey of Canada, nor of the closely allied species of the same
genus from Topsail Head, mentioned by Billings [1872b, p. 478]. Under the circumstances
nothing can be done but to decide from Billings’s description and figure [1872b, p. 477] the

_characters of the species, and refer to the species the form that can best be identified with the
description and figure as its typical representative. This appears to be the form from
the Lower Cambrian limestone of York County, Pennsylvania. (See pp. 345 and 350, and
Pl. II, figs. 1 and Ic.)

Ornamentation of the surface-—One of the most noticeable characters is the surface orna-
mentation. The type species of Micromitra (M. sculptilis (Meek), Pl. III, figs. 5, 5a—-c) has
on some specimens (PI. III, figs. 5c, 5d) concentric lines similar to those on the less ornamented
forms of the genus, as represented by Micromitra (Paterina) labradorica (Billings), and on other
specimens a well-defined series of radiating ridges of varying number, width, and strength
(Pl. III, figs. 5, 5a, and 5c). It was on account of the surface produced by the concentric lines
crossing the radiating ridges that the specific name sculptilis was proposed.

336 CAMBRIAN BRACHIOPODA.

Micromitra sculptilis (Meek), the type of group A (Jfcromitra Meek), is therefore inter-
mediate in surface characters between the concentrically striated forms of group B (Paterina
Beecher) and the network ornamentation of group @ (Iphidella Walcott), though some exam-
ples of the latter group have both the A and @ types of surface on the same shell. The species
with the intermediate type of surface may be grouped under the genus Micromuitra, as follows:

Micromitra alabamaensis (Walcott)...........---------------------- Middle Cambrian.
hay deniaWalcotien joss ose NIE See ei ee ae Do.
THUISUSHAWaAlCOUE) ia scae outs be Date corse OSE eee sen ays Do.
eal eix(Walcotit) me ao ceess nae co) 2 ee nepal Semen Do.

sspusillay@rmmarsson))) ote -ees sen ee ee eee eee Do.

SCOLLCA) WialCotteae. cee Sa sees ososia sinless eee eee Lower Cambrian.
sculptilish(Meek)2 Sis eer es ee ee ee oer os Middle and Upper Cambrian.
sculptilis endlichi Walcott. ..........--.-..--/---------- Middle Cambrian. ;
ZeNObIa WW alCotbe 5-25 32 nee ss sears liaise ee eee ees Do.

Micromitra (Paterina) labradoricaswantonensis (Walcott) and J (P.) bella (Bitings) represent
the second type (B), whose surface is formed of simple concentric striz and lines of growth. On
the basis of surface characters this group is given a subgeneric value, as suggested by Schuchert
[1905, p. 329], and the name Paterina of Beecher [1891, p. 345] is adopted.¢ The group includes:

Micromitra (Paterina) bella (Billings)......-....-....2..--22--22-2-22-+----2+----- Lower Cambrian.
Crenistria, (WalGott): sates qeiiauais ase aclbeineete sas se eve ae Middle Cambrian.
etheridcei (Daten eee eee ae ere ents, cea aoe eaeae Do.
laloradoricay (Bullies) Beers se eee ta araleee pepe rae Lower Cambrian.

onlentaliss(Walcoth)sese-4--5 see eee eee cee Do.
5 swantonensis (Walcott) .......--.------------- Do.
Uuitalensis) (Waleotit) seseses oes eee eese Middle Cambrian.
SVEUTA ULI CL 4 ey ree sacar eR Lower Cambrian.
Logan ((Walcobb) tedster iis Saprescre el Sear aie eel pia econ Middle Cambrian.
mayor(Walleoth)\ estates sis kets eb eeenise eee ee ae eee Lower Cambrian.
phillapsiy GEO) FBS eee ee es ee ee EE UE SS Upper Cambrian.
prospectensis| (Wallcoth) ese seems. o-oo ease eee Lower Cambrian.
unisswiaverernsiis; (UD yylalt)) “sega saccaeoss socanaocouuesce4csosacs Middle Cambrian.
ShIssingensisiorasWialcObter asses eens eee Do.
siuartl Walcott iste Oks ee Nal aate en oiele ee ter eesrotor Do.
superba (Walcot) merece catty te see bree ese ser attest ot Do.
tintdosa)((Mioberg) fies su Set see See SSR eee es ere Lower Cambrian.
Wwaptat Walcott svsse oie a ei a ws PE eet earns Do.
wallaardii Walcott ye i524 as See ee esa Pr sore ae Do.

Micromitra (Iphidella) ornatella (Linnarsson) and M. (/.) pannula (White) represent the
third type (C), whose surface is formed by the union of the crenulated striz so as to form a
fine network of raised obliquely arranged lines that divide the surface into minute pits that
give the impression of finely woven cloth. For the species with this ornamented surface
Iphidella Walcott [1905a, p. 304] is used in a subgeneric sense. This includes:

Micromitra (Iphidella) louise Walcott .............-..-..----------- Lower Cambrian.
myssa Walcott. 50. At Seely seefer ce Seen cay Middle Cambrian.
ornatella (Linnarsson) -....-...--+.-----2----- Do.
pannula (White) Pease ee nese a -e eeenaaeees Lower and Middle Cambrian.
maladensis (Walcott) .....--.-------- Middle Cambrian.
ophirensis (Walcott)....-....--------- Do.

Stratigraphic distrilution.—The genus ranges from low down in the Lower Cambrian
through the Middle Cambrian, and there are two species in the Upper Cambrian.

Of the Lower Cambrian species, V/. (I.) pannula (White) passes up into the central portion
of the Middle Cambrian in the Marjum limestone of the House Range section, Utah. Jhero-
matra sculptilis (Meek) occurs abundantly in the central portion of the Middle Cambrian and
has also been found in the Upper Cambrian Dunderberg shale of the Eureka district, Nevada.

Micromitra (Iphidella) pannula ophirensis (Walcott) has a range of 2,370 feet (722.4 m.)
in the House Range section of Utah, occurring in the Middle Cambrian at horizons 220, 2,075,
and 2,590 feet (67, 632.5, and 789.4 m.) above the quartzitic sandstones of the Lower Cambrian.

aJt is’ therefore impossible to use the type of the preoccupied genus Iphidea, Micromitra (Paterina) bella, as the type of this subgenus, as
Beecher founded it on ‘‘ Obolus labradoricus.’’ (See p. 344.)

a

PATERINIDA. dol

At Ophir, in the Oquirrh Range, it is at the horizon of the Pioche fauna, or near the base of
the Middle Cambrian.

The table in the introduction gives a summary of the numbers and the range of the genus
by species and varieties. (See p. 99.)

MIcROMITRA ALABAMAENSIS (Walcott).

Plate II, figures 5, 5a-c.

Iphidea alabamaensis Waucotr, 1897, Proc. U.S. Nat. Mus., vol. 19, pp. 713-714, Pl. LIX, figs. 5, 5a-b. (Discussed
somewhat as below as a new species. The specimens represented by figs. 5, 5a-b are redrawn in this monograph

Pl. II, figs. 5, 5a, and 5c, respectively.)

In following the Lower Cambrian rocks southward from Vermont, the first type of
Micromitra met with is M. stissingensis (Dwight), which occurs in the Middle Cambrian of
Dutchess County, New York. This is fairly well distinguished by its surface character from
Micromitra (Paterina) labradorica (Billings) and its variety swantonensis (Walcott), but at the
next locality to the south im eastern Tennessee, 4 miles (6.4 km.) north of Rogersville, in the
Rogersville shale of the Middle Cambrian, was found a form that is practically identical with
the northern species or its variety, so far as it is possible to compare specimens preserved in
limestone with those preserved in shale. A species of the same general form also occurs in the
Middle Cambrian shales of the Cowan Creek section, Cherokee County, Alabama. There is,
however, a difference in the surface striz that distimguishes it from MZ. (P.) labradorica, M. (P.)
labradorica swantonensis, and M. (P.) stissingensis. It is the tendency to crenulation of the
striz in nearly all the specimens that have been examined. This, in extreme cases, goes so
far as to approach the surface so characteristic of Micromitra ([phidella) pannula (White).
The form can not well be identified with the closely related M. (P.) labradorica (Billings) or its
variety swantonensis (Walcott) or M. (P.) stissingensis (Dwight) on account of these peculiar
surface characters, and the name JM. alabamaensis was proposed for it.

In the general form of the valves this species resembles M. (P.) labradorica and WV. (P.)
stissingensis. So far as known the only specific difference is im the surface character, which
allies it with Micromitra sculptilis (Meek). The convexity of the valves is unknown, owing to
the compression of the shells in the shale, and we have no information of the area or pseudo-
deltidium. Shell substance corneous.

FORMATION AND LOCALITY.—Upper Cambrian: (940) Limestone at base of dolomite, 0.25 mile (0.4 km.) beyond
Givens Ford, Cowan Creek, about 8 miles (12.8 km.) southeast of Center, Cherokee County, Alabama.

Middle Cambrian: (90x and 94a) In and attached to the outer surface of siliceous nodules in the Conasauga (‘‘Coosa”’)
shale, Coosa Valley, east of Center; (95a) shales on Spring Creek, near the old tram crossing north of Center road, Cowan
Creek valley, southeast of Center; and (94) shales 0.25 mile (0.4 km.) beyond Steel Ford, Cowan Creel, about 8 miles
(12.8 km.) southeast of Center; all in Cherokee County, Alabama.

(121a) Shales on road leading from southeast of Harlan Knob to Amis post office; (124) shales (Nolichucky?)
overlying the limestone which rests on the Rogersville shale, on Big Creek, southeast of Harlan Knob; (123) upper
part of Maryville limestone, on Big Creek, southeast of Harlan Knob; and (121) Rogersville shale, road just east of
Harlan Knob; all about 4 miles (6.4 km.) northeast of Rogersville [Keith, 1905, p.4, and areal geology sheet], Hawkins
County, Tennessee.

(14a) Sandstone of the Rome formation, along First Creek Gap, 4 miles (6.4 km.) north-northeast of Knoxville
[Keith, 1905, areal geology sheet], Knox County, Tennessee.

MicromitRA HAYDENI Walcott.

Text figures 20A—D, page 338.

Micromitra haydeni Waxcort, 1908, Smithsonian Mise. Coll., vol. 53, No. 3, pp. 55-56, PI. VII, figs. 3and 3a. (Described
and discussed as below as a. new species. Figs. 3 and 3a are copied in this monograph as figs. 20A and 20B’.)
Ventral valve subconical, with a minute beak arching slightly over a strong, arched pseudo-
deltidium which is about one-half as long as the height of the valve. Cardinal slope rounded;
a slight angle is indicated by a line where the concentric surface striz bend inward toward the
pseudodeltidium across the narrow area; a sharp angle is formed where the convex pseudodeltid-

ium rises abruptly from the area.

62667°—vo1 51, pr 1—12—22

338 CAMBRIAN BRACHIOPODA.

Dorsal valve moderately convex, most elevated at the small umbo just in advance of the
marginal minute beak; area very low and narrow, and without trace of pseudodeltidium so far
as now known.

Surface marked by fine, concentric, slightly undulating, threadlike strize and a varying
number of irregular, more or less interrupted, narrow, depressed, rounded radiating ridges;
these ridges are usually most numerous at the central portions of the valves. The concentric
strie extend across the narrow area and arch over the pseudodeltidium, where they are finer
and crowded together so that all the strie between the apex and the front margin are com-
pressed in about one-half the distance on
the pseudodeltidium. The adult ventral
valve is about 4.5 mm. in length by 5
mm. in width and 2.5 mm. in height, with
a pseudodeltidium 1.3 mm.in length. A
dorsal valve 2 mm. in length has a height
of about 0.5 mm.attheumbo. The shell
is rather thick for a species of this size,
and it is built up of several thin layers
or lamellee.

Observations.— Micromitra haydeni
differs from the nearest related species,
M. sculptilis (Meek), in having a strong
convex pseudodeltidium, less elevation
of the ventral valve, and a thicker shell.

FIGURE 20.— Micromitra haydeni Walcott. A, Top view of ventral valve(U.S.
Nat. Mus. Cat. No. 51437a). B, B’, Side and back views of a ventral a : 2
valve (U. S. Nat. Mus. Cat. No. 51437b)._C, Exterior of dorsal valve (U.S. hcromitra hayden occurs near the base

7 ( valve (U. §. A . No. . s ene
Pons Cat. No. 51437e). D, Dorsal valve (U. 8. Nat. Mus. Cat. No of the Middle Cambrian and iM. sculptilis

The specimens represented are from Locality 54s, Middle Cambrian lime- about 2,000 feet (610 m.) higher in the
stones, near Malade, Idaho. Figures 20A and 20B’ are copied from Walcott geetion of the Cambrian rocks of Utah and

[1908d, Pl. VII, figs. 3 and 2a]. Figure 20A represents the type specimen.
southern Idaho.

The specific name is given in honor of Dr. F. V. Hayden, geologist and explorer, under
whose charge the geology of this region was first studied.
ForMATION AND LOCALITY.—Middle Cambrian: (54s) Dark blue-gray Langston limestone [Walcott, 1908f, p. 198],

just above the Cambrian quartzitic sandstones, north side of Twomile Canyon, near its mouth, 2 miles (3.2 km.) south-
east of Malade, Oneida County, Idaho.

Micromirra nisus (Walcott).

U
Plate II, figure 10.

Tphidella wisus Waucort, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 305. (Described and discussed as below as a new
species. )

Ventral valve rather low, with the apex overhanging the posterior margin. Surface
marked by very fine lines of growth with still fer bands of striz between them. About 10
very fine radiating ridges extend from near the apex to the front and lateral margins.

This little shell is represented by a single specimen of the ventral valve. The associated
fauna includes fragments of Olenellus.

I was at first inclined to refer this shell to Micromitra sculptilis (Meek) or M. pealer (Wal-.
cott), but the overhanging apex and strongly marked surface and the fact that there is an
interval of 2,000 miles between the localities of the species led me to separate them. Strati-
graphically the two latter species occur in the Middle Cambrian and M. misus in the Lower
Cambrian. I do not think the two forms should be included in one species.

FORMATION AND LocaLiry.—Lower Cambrian: (2r) In a limestone bowlder in a conglomerate, in a railroad cut 2
niles (3.2 km.) west of Bic railway station, Rimouski County, Quebec, Canada.

PATERINIDZ. 339

w4 MicroMirraA PEALEL (Walcott).

Plate III, figures 3, 3a-e.

Tphidea pealei Waxcort, 1897, Proc. U. S. Nat. Mus., vol. 19, pp. 712-713, Pl. LIX, figs. 5, 3a-c. (Described and dis-
cussed as below as a new species. The two specimens represented by figs. 3, 3a—b, and 3c are redrawn in this
monograph, Pl. III, figs. 3, 3a—b, and 3c, respectively-)

Ventral valve subconical, beak slightly meurving over the pseudodeltidium. Cardinal
slope flattened to form a narrow false area, which is clearly defined from the curvature of the
shell by a slightly elevated threadlike ridge. Pseudodeltidium comparatively narrow, strongly
convex, and arched below. The strix of growth cross the false area and arch over the delthyrium.

Dorsal valve moderately convex, and without any special characteristics to distinguish it
from the same valve in Micromitra (Paterina) bella (Billmgs), MW. (P.) superba (Walcott), and
M. (P.) labradorica (Billings).

Surface marked by fine concentric striz and lmes of growth that are usually plain, but
in some examples are slightly crenulated. In such instances fine radiating lines or strie are
also shown. Shell substance corneous.

In the most perfectly preserved specimens there is a slight furrow or depression near the
apex of the ventral valve, but there is no trace of a perforation or apical opening.

This species approaches J. sculptilis (Meek) in some examples of the ventral valve. It
differs mainly in the narrow pseudodeltidium and the character of the surface markings. It
might be considered as a form intermediate between MV. (P.) bella (Billings) and J. sculptilis
(Meek).

The specific name was given in honor of Dr. A. C. Peale, of the Hayden Survey, who col-
lected the type specimen.

ForRMATION AND LOCALITY.—Middle Cambrian: (4n) Limestone about 325 feet (99.1 m.) above the unconformable
base of the Cambrian in divide at the head of Jackson Creek (locally known as Sheep Creek), a creek flowing into
Jackson Lake about 0.5 mile (0.8 km.) south of its northwestern corner, Teton Mountains, Grand Teton quadrangle
(U.S. Geol. Survey), Uinta County, Wyoming.

(159) Limestones north of West Gallatin (Gallatin) River, Gallatin County; (302) limestone east of Gallatin River,
above Gallatin, Gallatin County; (4p) about 225 feet (68.6 m.) above base of Cambrian in limestones interbedded in
Flathead shales of Peale [1893, p. 21], on the north side of West Gallatin (Gallatin) River, 2 miles (3.2 km.) north- _
east of Logan, Threeforks quadrangle (U.S. Geol. Survey), Gallatin County; (155a) limestone north of East Gallatin
River, near Hillsdale, Threeforks quadrangle (U. S. Geol. Survey), Gallatin County; (4h) about 375 feet (114.3 m.)
above base of Cambrian in limestone interbedded in the Flathead shales of Peale [1893, p. 21], 1 mile (1.6 km.) north
of the junction of East Gallatin and West Gallatin (Gallatin) rivers, 4 miles (6.4 km.) east-northeast of Logan,
Threeforks quadrangle (U.S. Geol. Survey), Gallatin County; (5f and 340) limestone interbedded in the Wolsey shale
[Weed, 1900, p. 285], in Meagher County on road to Wolsey, south of the divide at the head of Sawmill Creek, and
about 12 miles (19.3 km.) south of Neihart, Little Belt Mountains quadrangle (U. S. Geol. Survey), Cascade County;
(4x) limestone interbedded in the Wolsey shale [Weed, 1900, p. 285], at the base of a butte in Belt Park, about 6
miles (9.6 km.) northwest of Neihart, Little Belt Mountains quadrangle (U. 8. Geol. Survey), Cascade County; and
(9h) limestone on Beaver Creek, 5 miles (8 km.) north of York, about 8 miles (12.8 km.) north of Canon Ferry, Big
Belt Mountains, Fort Logan quadrangle (U. 8. Geol. Survey), Meagher County; all in Montana. x

(74) Sandstone about 300 feet (91.4 m.) above the base of the Tonto group, at the head of Nunkoweap Valley,
Grand Canyon of the Colorado, Arizona.

MicRoMITRA PUSILLA (Linnarsson).

Y Plate III, figures 2, 2a-c.

Kutorgina cingulata pusilla LInNarsson, 1876, Bihang till K. svensk. Vet.-Akad. Handl., Bd. 3, No. 12, p. 25, Pl. IV,
figs. 53 and 54. (Described as below, and discussed in English, as a new variety.)

Kutorgina cingulata Waxcort (in part) [not Brrurves], 1886, Bull. U. 8S. Geol. Survey No. 30, pp. 102-104. (Speci-
mens now referred to Micromitra pusilla were included with the specimens representing Kutorgina cingulata
when this description was written.)

Kutorgina cingulata pusilla Linnarsson, Matiry, 1902, Quart. Jour. Geol. Soc. London, vol. 58, pt. 1, pp. 146-147,
figs. 19 and 20, p. 147. (Discussed from a new locality.)

Kutorgina cingulata pusilla Linnarsson, GRONWALL, 1902, Danmarks Geol. Undersggelse, Reekke 2, No. 13, pp. 40-41.
(Discussed in Norwegian.)

340 CAMBRIAN BRACHIOPODA.

Linnarsson [1876, p. 25] gives the following description of the dorsal valve of this species:

Shell small, transversely oval, broadest about the middle. Hinge-line straight, shorter than the width of the
shell; cardinal angles rounded. Shell substance apparently corneous. Surface marked with numerous sharply
marked, concentric lines of growth. Length, 3mm.; breadth, 4mm.

In some material received from Andrarum, Sweden, I found what appear to be the ventral
and dorsal valves of this species associated with Micromitra ([phidella) ornatella (Linnarsson)
and Acrotreta socialis von Seebach. The ventral valve shows a well-defined false area on
each side of a triangular opening. The broken edge of the pseudodeltidium is shown on the
side of the upper end of the fissure, but its form and depth can not be determined.

This species is related to Micromitra (Paterina) labradorica (Billings), differmg from it
in having a less elevated ventral valve, radiating ridges on the surface, and bemg more uni-
formly smaller in size. It is evidently a rare form, as only three specimens were met with in
breaking up a large quantity of rock.

FoRMATION AND LOcALITY.—Middle Cambrian: (8w) Limestones of the Paradoxides forchhammeri zone, at Andra-
rum, 20 miles (32.2 km.) northwest of Simrishamn, Province of Christianstad; (320f) limestone at Andrarum, 20 miles
(32.2 km.) northwest of Simrishamn, Province of Christianstad; and (320u [Linnarsson, 1876, p. 25]) strata with
Agnostus lxvigatus at Ostra Rynninge, in Nerike; all in Sweden.

(16h) Limestones of the Paradoxides forchhammeri zone at Borregaard; and (16j) limestones of the Paradoxides forch-
hammeri zone at Laesa&i; both on Bornholm Island, Denmark. —

Matley [1902, p. 146] has identified this species from the following locality: 4

Upper Cambrian: (304b) Lower part of the ‘‘White Leaved Oak” shales (the zone of Polyphyma), Malvern Hills,
between Herefordshire and Worcestershire, England.

MicroMITRA SCOTICA Nn. sp.
¥ Text figures 21A-C.

Ventral valve moderately convex, transverse in outline. Beak almost apical, slightly in
advance of the posterior margin, which is nearly straight. Cardinal slopes flattened to form a
false area that is almost as wide
as the greatest width of the shell.
Pseudodeltidium narrow and arch-
ing somewhat above the plane of
the margin of the shell.

Dorsal valves unknown.

Surface marked by rather
coarse concentric striz and radiat-
ing ridges. The concentric striz
cross the false area and the pseu-
dodeltidium. -

Observations.—This species ap-
pears to be most closely related to
FIGuRE 21.— Micromitra scotica n. sp. A, Type specimen, a ventral valve, X4, from Local- Jcromitra pusiila (Linnarsson) ;

ity 816d, Lower Cambrian shale on Meall 4 Ghiubhais, Ross-shire, Scotland (U. S. 0 apie O
Nat. Mus. Cat. No. 58310). B,B’, B’’, Top, side, and back views of a ventral valve, X5, but is to be distinguished from that

from Locality 316d, Lower Cambrian shale on Meall 4 Ghiubhais, Ross-shire, Scotland gnpneej 7 reason of its ] o pseu-
(Geol. Survey Scotland, specimen No. M2646e). C, Top view of a crushed ventral Deeles by : it one P eu
valve, X2.5, from Locality 316d, on Meall 4 Ghiubhais, Ross-shire, Scotland (Geol. dodeltidium and the fact that the

Suryey scodaud, speciinen No: Meise: beak does not overhang the false
area. The latter species occurs in the Middle Cambrian and Micromitra scotica is associated
with Olenellus in Scotland.

ForRMATION AND LOCALITY.—Lower Cambrian: (316d) > Localities M2646e, M2647e, and M4178d of the Geological
Survey of Scotland, about 500 feet (152.5 m.) above the provisional base of the Cambrian and 75 feet (23 m.) below
what is believed to be the top of the Lower Cambrian in the shales forming 5 and 6 of the section given by Peach and
Horne [1907, p. 414], in a small burn on the north slope of Meall 4 Ghiubhais, 4 miles (6.4 km.) west-northwest of the
Kinlochewe Hotel, Loch Maree, Ross-shire, Scotland.

a Groom [1902, p. 109] describes the locality and cites a list of the asSociated species.
b Specimens from this locality are also included in the collections of the United States National Museum.

se

ee ee

PATERINIDA. a41

Micromirra scuLpritis (Meek).
Plate III, figures 5, 5a-e.

Iphidea (??) sculptilis MEK, 1873, Sixth Ann. Rept. U.S. Geol. and Geog. Survey Terr. for 1872, p. 479. (Described
and discussed as a new species, and the generic name ‘‘ Micromitra” proposed in case the species should prove
to belong to a new genus.)

Kutorgina minutissima Hatt and Wurrrrerp, 1877, U. 8. Geol. Expl. 40th Par., vol. 4, pt. 2, pp. 207-208, Pl. I, figs.
lland12. (Described and discussed asa new species. Thespecimens represented by figs. 11 and 12 are redrawn
in this monograph, Pl. III, figs. 5b and 5c, respectively.)

Kutorgina sculptilis (Meek), Waucorr, 1884, Mon. U. 8. Geol. Survey, vol. 8, p. 20, Pl. I, figs. 7, 7a—b, Pl. IX, fig. 7.
(The three specimens represented in Pl. J, figs. 7 and 7a, Pl. I, fig. 7b, and Pl. IX, fig. 7, are redrawn in this
monograph, PI. III, figs.5, 5b, and 5c, respectively.)

Iphidea sculptilis Meek, ScHucHErt, 1897, Bull. U. 8. Geol. Survey No. 87, p. 235. (Merely goes back to original
generic reference.)

Iphidea sculptilis Meek, Waucort, 1899, Mon. U. 8. Geol. Survey, vol. 32, pt. 2, pp. 447-448, Pl. LX, figs. 5, 5a-c.
(Discussed. The specimen represented by figs. 5, 5a-c is redrawn in this monograph, PI. III, fig. 5a.)

Iphidella sculptilis (Meek), Watcortr, 1905, Proc. U.S. Nat. Mus., vol. 28, p. 308. (Merely changes generic reference.)

In the description of [phidea (??) sculptilis, Meek [1873, p. 479] decided that as the shell
had a very narrow, slightly flattened margin on each side, representing a false area, and that
as there seemed to be a wide-open triangular foramen, it could be referred to the genus Acro-
treta or the genus [phidea. He was not positive that there was not a permanent pseudodel-
tidium present, but assuming the absence of that structure, and thinking it probable that when all
the characters of the shell were known it would be found to belong to a different genus, either of
the Brachiopoda or of some other group, he proposed for the genus the name ‘‘ Micromitra.”’

A study of the specimens of J. sculptilis collected from the same horizon, at a pomt not far
distant from the original locality, shows the presence of a false area and a pseudodeltidium of
the same type as that of Micromitra (Paterina) bella (Billmgs). There is, however, a difference
in the two forms that is considered of subgeneric value. The surface of MW. (P.) bella is covered
with fine concentric striz and the surface of Micromitra sculptilis is marked by very fine, sharp,
elevated concentric lines that coalesce or bifurcate irregularly, imparting a peculiarly inter-
rupted wavy appearance that is highly characteristic. The variation in the surface character is
continued still further in Micromitra ([phidella) pannula (White), in which the surface is divided
into minute porelike pits by a very fine network of oblique raised lines. Under the lens the
surface resembles that of finely woven cloth.

The most nearly related species is Micromitra haydeni Walcott, which has a similar surface,
but the latter has a large pseudodeltidium on the ventral valve, and that valye is more depressed
than in J. sculptilis.

A fragmentary ventral valve from 2,500 feet (762 m.) up in the Middle Cambrian series of
the northern Wasatch Mountains appears to be a form somewhat intermediate between Micro-
mitra (Paterna) crenistria (Walcott) and M. sculptilis. It has the surface of the latter except
that the radiating ribs are very faint. It occurs in the Blacksmith Fork section, east of Hyrum,
Utah.

ForMATION AND LOCALITY.—Upper Cambrian: (61) Limestone in the Dunderberg shale [Walcott, 1908f, p. 184],

a little south of the Hamburg mine; and (62) limestone in the Dunderberg shale [Walcott, 1908, p. 184], ina canyon

immediately north of Adams Hill; both in the Eureka district [Hague, 1892, Atlas], Eureka County, Nevada.

Middle Cambrian: (302) Limestone east of Gallatin River, above Gallatin; and (302a and 302c) limestones at several

places on the south side of the Gallatin Valley; both in Gallatin County, Montana.

(302b) Limestones near Crowfoot Ridge, Gallatin quadrangle (U.S. Geol. Survey), Yellowstone National Park,
Wyoming.

(55n) About 1,850 feet (564 m.) above the Brigham quartzite and 2,350 feet (716 m.) below the Upper Cambrian
in the limestones forming 2¢ of the Bloomington formation [Walcott, 1908f, p. 195], in Blacksmith Fork Canyon, about
10 miles (16.1 km.) east of Hyrum, Cache County, Utah.

(8i) Shales believed to be referable to the lower portion of the Marjum limestone [Walcott, 1908f, p. 180],
found about 0.5 mile (0.8 km.) east of Antelope Springs; (8x) about 2,200 feet (670.6 m.) above the Lower Cambrian
and 2,200 feet (670.6 m.) below the Upper Cambrian in the limestones forming 1d of the Marjum limestone [Walcott,
1908f, p. 180], 2.5 miles (4 km.) east of Antelope Springs in ridge east of Wheeler Amphitheater; and (10y) about 2,900

342 - CAMBRIAN BRACHIOPODA.

feet (884 m.) above the Lower Cambrian and 1,500 feet (457.2 m.) below the Upper Cambrian in the central part of
the bed forming la of the Marjum limestone [Walcott, 1908f, p. 179], about one mile (1.6 km.) south-southwest of Marjum
Pass; all in the House Range [Walcott, 1908f, Pl. XIII], Millard County, Utah.

(11s) Shales just above Simpson Spring, about 20 miles (32.2 km.) west-southwest of Vernon, on the stage road from
Vernon to Fish Spring, Tooele County, Utah. :

(10w) Shaly limestones about 5 miles (8 km.) northeast of Osceola, on the east side of the Snake Range, White
Pine County; and (58) shaly limestones in upper beds of Secret Canyon shale, either in New York or Secret Canyon,
Eureka district [Hague, 1892, Atlas], Eureka County; both in Nevada.

Specimens that are compared with Micromitra sculptilis occur at the following locality:

Middle Cambrian: (541) About 2,950 feet (899.2 m.) above the Brigham quartzite and 1,225 feet (373.4 m.) below
the Upper Cambrian in the limestone forming le of the Bloomington formation [Walcott, 1908f, p. 194], in Blacksmith
Fork Canyon, about 10 miles (16.1 km.) east of Hyrum, Cache County, Utah.

MicROMITRA SCULPTILIS ENDLICHI Walcott.

Text figure 22.

Micromitra sculptilis endlichti Waxcotr, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, p. 56. (Characterized as below
as a new variety.) :

This form is represented by a single specimen of a ventral valve. The surface is similar
to that of Micromatra sculptilis (Meek), but the valve is more elongate,
less elevated, and larger (5 mm. in diameter) than the specimens of
the latter from the type locality. j

The varietal name is given for Mr. F. M. Endlich of the Hayden
Survey.

FoRMATION AND LOCALITY.—Upper Cambrian: (80) Limestone 2 miles (3.2 km.)
north of Aurum, Schell Creek Range, White Pine County, Nevada.

MiIcROMITRA ZENOBIA Na. sp.
Figure 22.— Micromitra sculplilis |

endlichi Walcott. A, A’, Top Text figure 23.
and side views of the type speci- E i ; '
men, a ventral valve from Local- Most of the specimens of this species are flattened in the shale,

ity 80, Upper Cambrian lime- : 3
Eanek omiiles/ Glen ywortnlaf but both valves appear to have been moderately and nearly equally

Aurum, White Pine County, convex. The beak of the ventral valve is slightly in advance of the

ee: S. Nat. Mus. Cat. osterior margin and incurves slightly over a well-defined cardinal

slope which is nearly straight and almost as wide as the greatest diam-

eter of the shell. The pseudodeltidium is moderately convex and apparently extends about
half the distance from the beak to the posterior margin.

Growth lines are fairly coarse and regular. In the ventral valve they bend abruptly at
the cardinal slope, on which they are very fine and very irregular. In
other words, the cardinal slope is well defined and is covered with an
irregular confusion of minute ridges which seem to bear little relation
to the concentric ridges on the surface of the shell. This pattern can
not be seen on the pseudodeltidium.

In some of the adult shells from the type locality (35k) a faint
radial crenulation can be seen near the apex. Fragments of lime-
stone (Locality 57c) contain many small shells, probably the young,
with radial folds and a crenulation of the concentric striz similar to Fee Rt Ra ar eee ee
that in Micromitra sculptilis. The crenulations have been observed ventral valve from Locality 36k,
in one perfectly preserved adult specimen. The specimens from the He eerie eee cot ol

tion 1 mile (1.6 km.) northeast of

limestone may be distinct. — Burgess Pass, above Field, British
Columbia (U. S. Nat. Mus. Cat.

FoRMATION AND LOCALITY.—Middle Cambrian: (35k) Burgess shale member of the —_No. 58311)
Stephen formation, west slope of ridge between Mount Field and Wapta Peak, 1 mile
(1.6 km.) northeast of Burgess Pass, above Field; and (58 1) about 1,830 feet (557.8 m.) above the Lower Cambrian in
the limestone forming 3b of the Stephen formation [Walcott, 1908c, p. 238 (7)], on the east side of Mount Stephen
about 3,000 feet (914.4 m.) above the Canadian Pacific Railway track 3.5 miles (5.6 km.) east of Field; both in British
Columbia.

PATERINIDL. 348

(5%c) About 2,500 feet (762 m.) above the Lower Cambrian and 2,475 feet (754 m.) below the Upper Cambrian
in the limestone forming 1 of the Stephen formation [Walcott, 1908f, p. 209]; and (58z) about 1,875 feet (572 m.) above
the Lower Cambrian and 3,100 feet (945 m.) below the Upper Cambrian in the limestone forming 2b of the Stephen
formation [Walcott, 1908f, p. 211]; both on Mount Bosworth, north of the Canadian Pacific Railway between Hector
and Stephen, on the Continental Divide between British Columbia and Alberta, Canada.

Micromirra sp. undt. (Walcott).

Plate III, figure 7.

Iphidea sp. undet., Waxcort, 1899, Mon. U. S. Geol. Survey, vol. 32, pt. 2, p. 449, Pl. LX, fig. 6. (Described and
discussed as below as an undetermined species. The specimen represented by fig. 6 is redrawn in this mono-
graph, Pl. III, fig. 7.)

Iphidella sp. undt., Waucorr, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 305. (Description and discussion copied from
preceding reference.)

Dorsal valve semicircular, slightly convex. Hinge line somewhat shorter than the width
of the shell below; nearly straight, the rostral angle about 180°. Beak small, not elevated.
Surface ornamented by extremely fine, radiatmg, and undulating concentric strie that can
be seen in detail only with a strong magnifying glass. Shell substance horny.

This form is associated with Micromitra sculptilis (Meek) and, judging from external
characters, is closely related to it. The surface ornamentation is of the same character, and,
in the absence of the ventral valve, it is difficult to distmguish any specific charactars on which
to base a new species, although the shell is much larger than that of M. sculptilis.

FoRMATION AND LOCALITY.—Middle Cambrian: (302b) Limestones near Crowfoot Ridge, Gallatin quadrangle
(U.S. Geol. Survey), Yellowstone National Park, Wyoming.

PATERINA Beecher,¢ subgenus of MICROMITRA.
[/Pater, father.]

Kutorgina Dati (in part) [not Brtines], 1877, Bull. U. S. Nat. Mus. No. 8, pp. 40-41. (Includes reference to speci-
mens now referred to Micromitra (Paterina).)

Kutorgina Watcort (in part) [not Brurines], 1886, Bull. U. S. Geol. Survey No. 30, pp. 101-102. (Genus Kutorgina
described, but description also includes reference to specimens now referred to Micromitra, Micromitra (Paterina),
and Micromitra (Iphidelia).)

Paterina BEEcHER, 1891, Am. Jour. Sci., 3d ser., vol. 41, p. 345, and footnote. (Gives reasons for proposing Paterina as
a hew genus.)

Paterina Beecher, Hatt and CiarKeE, 1892, Eleventh Ann. Rept. State Geologist New York for 1891, p. 247. (De-
scribed.)

Iphidea Billings, Hatt and CrarKE, 1892, idem, p. 249. (Described and accompanied by figures of specimens referred
to the subgenus Paterina.)

Paterna Beecher, Hatt and CiarKe, 1892, Forty-fifth Ann. Rept. New York State Museum for 1891, p. 563. (Copy
of Hall and Clarke, 1892a, p. 247.)

Iphidea Billings, Hatt and CrarKe, 1892, idem, p. 565. (Copy of Hall and Clarke, 1892a, p. 249.)

Kutorgina Hatt and CuaRkeE (in part) [not Bmures], 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, pp.
90-94. (Copies Walcott’s description [1886, pp. 101-102] and discusses genus, but description and discussion
also include reference to specimens now referred to Micromitra, Micromitra (Paterina), Micromitra (Iphidelia),
Protorthis, and Billingsella.)

a The synonymy for this subgenus does not give a complete record of the various genera under which the species now included in Paterina were
formerly placed; it includes only those references in which the subgenus is discussed or described. For the sake of completing the record the remain-
ing mere generic references are here listed:

Obolus Billings [1861b, p. 6; 1861c, p. 946; 1862e, Iphidea Oehlert [1887, p. 1270].
p. 218; 1863, p. 284]. Kutorgina Dwight [1889, p. 145].
Obolella Holl (1865, p. 102]. Kutorgina Walcott [1890, p. 36].
Obolella ? Davidson [1866, p. 62]. Kutorgina Dwight [1891, p. 105].
Kutorgina Davidson |1868, p. 312; 1871, p. 342]. Iphidea Walcott [1891a, p. 608].
Obolella Phillips [1871, p. 68]. Kutorgina Walcott [1891a, p. 609].
Iphidea Billings [1872b, p. 477; 1874, p. 76]. Kutorgina Moberg [1892b, p. 112).
Obolelius ? Roemer [1876, Pl. II, figs. 6a-d]. Platyceras Tate (1892, p. 184].
Obolella Dall (1877, p. 41]. Iphidea Hall and Clarke [1892c, Pl. IV, figs. 6 and 7].
Iphidea Billings [1882, p. 13]. Iphidea Grabau [1900, p. 617].
Kutorgina Davidson [1883, p. 212]. Kutorgina Matley [1902, p. 145].
Kutorgina Walcott [1884b, p. 19]. Micromitra Clark and Mathews [1906, p. 252).

Iphidea Walcott [1886b, p. 100}.

Bale CAMBRIAN BRACHIOPODA.

Tphidea Billings, Waxcott (in part), 1897, Proc. U. 8. Nat. Mus., vol. 19, pp. 707-711. (Discussed. The genus as
discussed includes species now referred to Micromitra, Micromitra (Paterina), and Micromitra (Iphidella).)

Paterina Beecher, Watcott, 1897, idem, p. 708. (Discussed as synonym of [phidea.)

Iphidea Billings, ScHucHERT (in part), 1897, Bull. U. S. Geol. Survey No. 87, p. 233. (Merely refers Micromitra and
Paterina to Iphidea.)

Iphidella Waucorr (in part), 1905, Proc. U. S. Nat. Mus., vol. 28, p. 304. (Merely proposed to replace Iphidea, but
includes reference to specimens belonging with Micromitra, Micromitra (Paterina), and Micromitra (Iphidella).)

Iphidea Billings, GraBav and Sumer (in part), 1907, North American Index Fossils, vol.1,p.201. (Described, and
includes species referred to each of the subgenera Paterina and Iphidella.)

Micromitra (Paterina) (Beecher), Watcott, 1908, Smithsonian Misc. Coll., vol. 53, No. 4, Pl. XI, and pp. 142 and 148.
(Classification of subgenus. )

All of the species of Micromitra with plain concentric striz on the outer surface are grouped
under Paterina as a subgenus. Beecher [1891, p. 345] quoted ‘‘ Obolus labradoricus Billings”’ as
the type of his genus Paterina, supposing that the species represented the simplest form of
brachiopod known. The genus was subsequently shown [Walcott, 1897b, p. 707] to have been
previously described [Meek, 1873, p. 479] under a different name, Micromitra (Iphidea being
preoccupied [Schuchert, 1905, p. 329]), but as it appears necessary to group the shells of which
Micromitra (Paterina) levadlar sien (Billings) is a typical ecumple under a subgenus, I have
adopted Paterina as the name for it.

Type.— Kutorgina labradorica swantonensis Walcott [1890, p. 36].

Beecher studied the specimens of the variety Micromitra (Paterina) labradorica swantonensis
(Walcott) which were in my laboratory in the United States National Museum and did not at
the time have the specimens of ‘‘Obolus labradoricus”’ from the St. Lawrence Valley. He
mistook the duplicate specimens of the variety for the species, and it was from the material he
examined that the area of the ventral valve was subsequently worked out, as shown on Plate
II, figures 3d, 3e, and 3f.

A list of the species referred to Paterina has been given under the genus Micromitra (p. 336).

MicromiTrRA (PATERINA) BELLA (Billings).
V Plate II, figures 1, lac.

Iphidea bella Brxurnes, 1872, Canadian Naturalist, 2d ser., vol. 6, No. 4, pp. 477-478, fig. 13. (Described and discussed
as a new species; see p. 345, for copy. Fig. 13 is reproduced in this monograph, PI. II, fig. Ic.)

Tphidea bella Brxuxnes, 1874, Geol. Survey Canada, Paleozoic Fossils, vol. 2, pt. 1, p. 76, fig. 44. (Description and
ficure copied from preceding reference.)

Tphidea bella Bruuincs, 1882, Geol. Survey Newfoundland, Rept. Progress for 1881, Appendix, p. 18, fig. No.8. (A
copy of the preceding reference.)

Tphidea bella Billings, Waucort, 1886, Bull. U. S. Geol. Survey No. 30, p. 100, Pl. VII, fig. 4. (Copies the original
description, Billings, 1872b, pp. 477-478, and discusses species. Fig. 4 is copied from Billings, 1872b, fig. 13,
p. 477.)

Iphidea bella Billings, OrHLERT, 1887, Manuel de conchyliologie, by Fischer, P. 1270, fig. 1026. (Mentioned in
French. Fig. 1026 is copied from Billings, 1872b, fig. 13, p. 477.)

Iphidea bella Billings, Waucorr, 1891, Tenth Ann. Rept. o, S. Geol. Survey, p. 608, Pl. LXVII, fig. 6. (Mentioned.
Fig. 6 is copied from Billings, 1872b, fig. 13, p. 477.)

Not Iphidea bella Hatt and CrarKe, 1892, Eleventh Ann. Rept. State Geologist New York, for 1891, p. 249, Pl. IV,
figs. 4 and 5. (Mentioned. Referred in this monograph to Micromitra (Paterina) labradorica swantonensis.)

Iphidea bella Billings, Haut and Cxrarke (in part), 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, p. 98, fig.
54, not Pl. IV, figs. 8 and 9. (Mentioned in the text. Fig. 54 is copied from Billings, 1872b, fig. 18, p. 477.
The specimens represented by figs. 8 and 9 are referred in this monograph to Micromitra ecema) labradorica
swantonensis. ) ‘

Iphidea bella Billings?, GraBav, 1900, Occas. Papers Boston Soc. Nat. Hist., No. 4, vol. 1, pt. 3, pp. 617-618, Pl. XX XT,
fig. 2. (Described and discussed.)

Micromitra bella (Billings), CLark and Lame, 1906, Maryland Geol. Survey, vol. 6, pt. 1, p. 252, Pl. XVI, fig. 15.
(No text reference. Fig. 15 is copied from Walcott, 1886, Pl. VII, fig. 4.)

Iphidea bella Billings, GRaBAU and SurveR, 1907, North American Tilo Fossils, vol. 1, p. 201, fig. 234h, p. 199.
(Described. Fig. 234h is copied from Billings, 1872b, fig. 13, p. 477.)

The shell described and illustrated by Billings [1872b, pp. 477-478] had a large false area
and a convex pseudodeltidium, the width of ohne at the hinge line was stated to be nearly
one-third the whole width of the shell.

re

PATERINIDA. 345

T received from Whiteaves what was supposed to be the type specimen of the ventral valve,
from Trois Pistoles, but I find that it does not belong to the species described by Billings
[1872b, p. 477]. The area is strongly marked, but the pseudodeltidium in the specimen before
me is very short, not over one-fifth the height of the deltidial area. In this respect it resembles
the pseudodeltidium of Micromitra (Paterina) crenistria (Walcott). It is described in this
monograph as M. (P.) logani (Walcott). Under date of July 23, 1896, Professor Whiteaves
wrote that there were no other specimens or electrotypes of the types of JM. (P.) bella (Billings)
in the collections of the Geological Survey of Canada, nor of the closely allied species of the
same genus from Topsail Head, mentioned by Billings [1872b, p. 478]. (See pp. 335 and 350,
and Pl. II, figs. 1 and 1c.)

Billings [1872b, pp. 477-478] describes the genus and species as follows:

The ventral ? valve of J. bella is conical, strongly elevated at the beak, hinge line nearly straight, posterior angles
narrowly rounded, sides and front nearly uniformly rounded, forming rather more than a semicircle. Posterior side
with a large false area and a convex pseudodeltidium, the width of which at the hinge line is nearly one-third the
whole width of the shell. The dorsal valve is semicircular, moderately convex, most elevated at the beak. The hinge
line appears to be straight. The form and structure of the posterior side (such as the area, foramen, deltidium, etc.)
can not be made out from the specimen, owing to its imperfection. The surface is covered with fine concentric stric,
which in the ventral? valve are continued around on the area. Of these strize there appear to be from fifteen to twenty
in the width of one line, their size varying somewhat in different parts of the specimen. There are also a few obscure
radiating striz. Width of ventral valve, seven lines; length, five lines; height, two lines.

Very little is to be added to this description from a study of the material from the north
side of the Straits of Belleisle and from Pennsylvania, except that the examination of a num-
ber of specimens has revealed the fact that there is no true perforation in the beak. Billings
states that in the specimen described by him there is an aperture in the beak, but in another
there is no appearance of one. I observed a narrow furrow near the apex of the beak in
a specimen from L’Anse au Loup, Labrador, but there was no aperture through the shell.
Several other specimens afford no traces of even a slight slit in front of the beak. The presence
of this depression or furrow is mentioned, and its character set forth in the description of the
genus Micromitra (p. 335).

ForRMATION AND LOCALITY.—Lower Cambrian: (2n) Limestone bowlders in conglomerate, along the shore of the St.
Lawrence, near Trois Pistoles, Temiscouata County; and (20) limestone bowlders in conglomerate on shore at east entrance
to harbor at Bic, Rimouski County; both in Quebec, Canada.

(314e [Billings, 1872b, p. 478]) Limestone at Topsail Head, Conception Bay, Newfoundland.

(392a) Limestone [Walcott, 1891b, p. 254] at L’Anse au Loup, on the north shore of the Straits of Belleisle,
Labrador.

(326g [Grabau, 1900, p. 617]) Limestones at Hast Point, Nahant, Essex County, Massachusetts.

(49) Sandstone on Codorus Creek, 0.125 mile (0.2 km.) below Meyer’s mill, near Emigsville, York County;
(846a) limestones in Landis Valley, Lancaster County; and (49w) limestones in railroad cut 0.25 mile (0.4 km.) south
of Emigsville, York County; all in Pennsylvania.

(25) Sandstone just above Parker’s quarry, near Georgia, Franklin County, Vermont.

MicroMiITRA (PATERINA) CRENISTRIA (Walcott).

Plate III, figures 4, 4a—b.

Iphidea crenistria Waxtcotr, 1897, Proc. U. 8. Nat. Mus., vol. 19, p. 713, Pl. LIX, figs.4,4a-b. (Described and discussed
essentially as below as a new species. The specimen represented by figs. 4, 4a—b is redrawn in this monograph,

Pl. III, figs. 4, 4a-b.)

Ventral valve subconical, beak nearly apical, curving slightly over to the pseudodeltidium.
False area very narrow, separated from the curvature of the shell by being turned somewhat
abruptly backward. Pseudodeltidium comparatively broad, but decidedly short as compared
with that of Micromitra (Paterina) bella (Billings) or M. (P.) superba (Walcott). It is more
the type of that of I. (P.) labradorica (Billings). It is strongly arched, leaving a broad, high
space between it and the plane of the shell.

Dorsal valve unknown. Surface of ventral valve marked by very fine, slightly crenulated
striz that are so crowded on the false area that they are nearly lost, and only one or two varices
of growth and a few striz are shown on the pseudodeltidium. No traces of an apical opening
have been seen. On some shells a faint furrow is seen on the apex.

346 CAMBRIAN BRACHIOPODA.

This species is clearly distinguished from other described forms of the subgenus by its
highly arched pseudodeltidium and crenulated surface striz.

An imperfect ventral valve from the upper portion of the Secret Canyon shale of the Hureka
district section, Nevada, has somewhat coarser striz than this species, but otherwise it appears to
bethe same. Specimens from near Schellbourne, Nevada, appear to be identical with the Grand
Canyon form. A single imperfect ventral valve, from the Orr formation, 930 feet above the
base of the Upper Cambrian, in the House Range section of Utah,is very much like the specimen
from the Secret Canyon shale of Nevada and is tentatively placed with it under this species.
The Grand Canyon, Utah, and Nevada shells appear to be descendants of MW. (P.) labradorica
of the Lower Cambrian and its varieties in the lower portion of the Middle Cambrian of the
Cordilleran region.

This ‘om owes its specific name to the finely crenulated striz with which its outer surface
is characterized.

FoRMATION AND LOCALITY.—Upper Cambrian: (313) Limestone 0.75 mile (1.2 km.) east-northeast of McGill post
office, White Pine County, Nevada.

Middle Cambrian: (75) ‘‘Tonto” sandstone, near the water’s edge, at the mouth of Kanab Canyon, where it
enters the Grand Canyon of the Colorado; (73b) sandstone in upper part of Tonto group, lower portion of Kwagunt
Valley, Grand Canyon of the Colorado; and (74) sandstone about 300 feet (91.4 m.) above the base of the Tonto group, at
the head of Nunkoweap Valley, Grand Canyon of the Colorado; all in Arizona.

(313b) Limestone 3 miles (4.8 km.) north-northeast of Schellbourne, Schell Creek Range, White Pine County,
Nevada.

(18b) Sandstones of the Rome formation, northeast of Rhea Springs [Hayes, 1894, areal geology sheet], Roane
County, Tennessee.

Specimens somewhat doubtfully referred to this species occur at the following localities:

Upper Cambrian: (30j) About 950 feet (289.6 m.) above the Middle Cambrian and 2,450 feet (746.8 m.) below the
top of the Upper Cambrian near the base of the arenaceous shales and limestone forming le of the Orr formation [Wal-
cott, 1908f, p. 176], on Orr Ridge, about 5 miles (8 km.) south of Marjum Pass, House Range [Walcott, 1908f, Pl. XIIT],
Millard County, Utah.

Middle Cambrian: (58) Shaly limestones in the upper beds of the Secret Canyon shale, east side of New York and
Secret canyons, Eureka district [Hague, 1892, Atlas], Eureka County, Nevada.

Mricromirra (PATERINA) ETHERIDGE! (Tate).

Plate III, figures 10, 10a—c.

Platyceras etheridgei Tate, 1892, Trans. Roy. Soc. South Australia for 1892, vol. 15, pt. 2, p. 184, Pl. II, figs. 7a-c. (De-
scribed and discussed as a new species. The two specimens represented by figs. 7a-c are redrawn in this
monograph, Pl. III, figs. 10, 10a—b.)

The original description by Tate follows:

Shell small, broadly conical; apex obtuse, posterior, recurved, but not spiral, usually protruding beyond the pos-
terior margin; aperture roundly oval, but irregular in outline, subtruncated and narrowed posteriorly. Surface orna-
mented with rather thick subimbricating concentric folds of growth, and curved beneath the apex coincidently with
the posterior margin; faintly radially wrinkled.

This very common species exhibits considerable variability in the outline of the aperture, and the amount of back-
ward projection of the apex. The shells seem to have lived on irregular surfaces, and in some instances at least upon
trilobites. The proportionate measures of the basal diameter and height are as 4 to 3; the longest diameter observed is 6
mills.

The examination of the type specimen of this species shows that the shell substance is
corneous, that there is a true false area, and that the species is closely related to Micromitra
(Paterina) superba (Walcott). All of the specimens in the collection are ventral valves, and
these differ considerably in elevation, apparently owing to the upward arching of the posterior
margin beneath the false area. This characteristic distinguishes the species from IM. (P.)
superba and allied forms.

The specific name was given in honor of Dr. R. Etheridge, jr.

FORMATION AND LOCALITY.—Middle ? Cambrian: (315 [Tate, 1892, p. 184]) Limestone at Curramulka, Yorke
Peninsula, South Australia.

PATERINIDZ. 347

Micromirra (PATERINA) LABRADORICA (Billings).
Plate II, figures 2, 2a-f.

Obolus labradoricus Brntines, 1861, Geol. Survey Canada, Paleozoic Fossils, vol. 1, p. 6, fig. 6.
species. The specimen represented by fig. 6 is redken fl in this ponoeEeh: PL ii, fee 2.)

Obolus labradoricus Brntines, 1861, Report on the Geology of Vermont, vol. 2, p. 946, fig. 3 345.
reference.)

Obolus labradoricus Bittines, 1862, Report on the Economic Geology of Vermont, by Hager, p. 218, fig.345. (Copy
of preceding reference.)

Obolus labradoricus BrxtINGs, 1863, Geol. Survey Canada, Fifteenth Rept. Progress, p. 284, fiz. 291. (No text reference.
Fig. 291 is copied from Billings, 1861h, fig. 6, p. 6.) ;

Iphidea labradorica Bruurincs, 1872, Canadian Naturalist, 2d ser., vol. 6, No. 4, p. 478. (Merely changes generic
reference.)

Iphidea labradorica Brttrnes, 1874, Geol. Survey Canada, Paleozoic Fossils, vol. 2, pt. 1, p. 76. (Copy of preceding
reference.)

Kutorgina labradorica (Billings), Watcorr (in part), 1886, Bull. U. S. Geol. Survey No. 30, p. 104, not Pl. IX, figs. 2
2a-b. (Original description, Billings, 1861b, p. 6, copied and species discussed. The specimens iad,
however, belong with Micromitra Gan) labradorica swantonensis.)

Not Paterina labradorica BrrcuER, 1891, Am. Jour. Sci., 3d ser., vol. 41, footnote, pp. 345-346, Pl. XVII, figs. 1 and 2.
(The specimens here referred to belong with Micromitra (Paterina) labradorica swantonensis.)

Kutorgina labradorica (Billings), Watcorr, 1891, Tenth Ann. Rept. U. S. Geol. Survey, p. 609, Pl. LXIX, figs. 3, 3a-b.
(Mentions new locality. The specimens represented by figs. 3, 3a—b are redrawn in this monograph, PI. II,
figs. 2d, 2c, and 2a, respectively.)

Not Paterina labradorica Hatt and CuarxKe, 1892, Eleventh Ann. Rept. State Geologist New York, for 1891, p. 247,
fig. 258. (Genus Paterina described. Fig. 258 is copied from Walcott, 1886b, Pl. IX, figs. 2b and 2a, but the
specimens belong with Micromitra (Paterina) labradorica swantonensis.)

Iphidea labradorica (Billings), SchucHERT (in part), 1897, Bull. U.S. Geol. Survey No. 87, p. 234. (Accepts Billings’s
reference of ““Obolus labradoricus” to Iphidea, but includes reference to specimens of Micromitra (Paterina)
labradorica swantonensis.)

Iphidella labradorica Waxcort, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 307. (Merely changes generic reference.)

(Described as a new

(Copy of preceding

Ventral valve depressed, conical; the beak high and arched over the narrow area. Car-
dinal slopes flattened so as to form a narrow false area, which is clearly defined from the
curvature of the shell by a sharp angle; pseudodeltidium unknown.

Dorsal valve moderately convex, transverse, the hinge line being usually a little shorter
than the greatest width of the shell below. Beak small, slightly incurving over the pseudo-
deltidium. In some specimens there is a broad low mesial sinus, while in others this feature
is scarcely discernible. Cardinal slope nearly vertical, forming a clearly defined narrow area,
broken at the center by a broad pseudodeltidium, the center of which is marked by a rather
broad, slight groove. The pseudodeltidium is well shown in two specimens, but the details
of its characters are not so well exhibited as in specimens of the dorsal valve of Micromitra
(Iphidella) pannula (White). Striz of growth cross the false area and pseudodeltidium.

The surface is marked by rather fine concentric striz that are quite regular near the apex
of the shell, but less so outward toward the margin, as shown by the type specimens that
Whiteaves kindly sent on to me for study. These also show fine, radiating striz that cross
the concentric striz and lines of growth, giving to the striz a slightly crenulated appearance
somewhat similar to that of Micromitra (Paterina) prospectensis (Walcott). Where the shell
is exfoliated, radiating strie are distinctly shown on the cast of the interior. On specimens
from the limestone carrying Olenellus, etc., at Topsail Head, Conception Bay, Newfoundland,
the surface striz are less distinctly mmendeed and the shells are smaller, but there appears to ihe
no specific difference between those from the Straits of Belleisle. Shell substance corneous.

With a type specimen from L’Anse au Loup before me for comparison with the form from
the Lower Cambrian limestone east of Swanton, Vermont, I am still inclined to distinguish the
latter as the variety swantonensis. The striz oF the Smamnion shells are usually finer and more
regular and the valves less transverse in proportion to the length. It is quite probable that
these differences would largely disappear on the comparison of a larger series of specimens
from the type locality, as there is a considerable range of variation among those from east of
Swanton and those from Topsail Head.

348 CAMBRIAN BRACHIOPODA.

In the Hanford Brook section of New Brunswick I found very good illustrations of this
species in Matthew’s ‘‘ Etcheminian.”
: This form owes its specific name to its occurrence at the Straits of Belleisle, Labrador.

ForMATION AND LOCALITY.—Lower Cambrian: (41a) Limestone [Walcott, 1891b, p. 260] on the mainland beneath
Topsail Head, Conception Bay; (314e [Walcott, 1886a, p. 150]) limestone at Topsail Head, Conception Bay; (5r) lime-
stone near the railroad track 1.5 miles (2.4 km.) west of the railway station at Manuels, Conception Bay; (5t) shale
and limestone nodules about 20 feet (6 m.) above the base of the Cambrian, on Redrock Point, near Chapple Cove,
Hollywood Point, Conception Bay; (51) limestone on Smith Point, in Smith Sound, Trimity Bay; and (314f) lime-
stone of B7 of the section at Bonne Bay [Walcott, 1891b, p. 255]; all in Newfoundland.

(392a) Limestones | Walcott, 1891b, p. 254] at L’ Anse aw Loup on the north shore of the Straits of Belleisle, Labrador.

(3a) 450 feet (137.1 m.) below the quartzite in the St. John formation and over 500 feet (152.4 m.) below the
Protolenus zone of Matthew [Walcott, 1900, pp. 320-322], Hanford Brook; and (801v [Walcott, 1900, p. 322]) sandy
shales of Division 2b of the ‘‘basal series’’ of Matthew, on Hanford Brook; both in St. John County, New Brunswick.

(20) Limestone bowlders in conglomerate on shore at east entrance to harbor at Bic, Rimouski County, Quebec.

(2b) Limestone just north of Beman Park, in the northeastern part of the city of Troy, Troy quadrangle (U.S. Geol.
Survey), Rensselaer County, New York.

(3040) Sandstone at Nuneaton, England.

(1v) Shales of No. 3 of the Silver Peak group, Barrel Spring section [Walcott, 1908f, p. 189], 3 miles (4.8 km.)
north of Valcalda Spring and 4 miles (6.4 km.) west-northwest of the Drinkwater mine, Silver Peak quadrangle
(U. S. Geol. Survey), Esmeralda County, Nevada.

(57r and 58s) About 150 feet (46 m.) below the Middle Cambrian near the base of the limestones forming 3 of
the Mount Whyte formation [Walcott, 1908c, p. 241 (10)], just above the tunnel on the north shoulder of Mount
Stephen, about 3 miles (4.8 km.) east of Field, British Columbia.

Specimens somewhat doubtfully referred to this species occur at the following locality:

Lower Cambrian: (2r) Limestone bowlders in a conglomerate in a cut on the Intercolonial Railway, 2 miles
(3.2 km.) west of Bic railway station, Rimouski County, Quebec.

MicromitRa (PATERINA) LABRADORICA ORIENTALIS (Walcott).
4

Plate II, figure 11.

Iphidella labradorica orientalis Watcorr, 1905, Proc. U. 8. Nat. Mus., vol. 28, pp. 305-306. (Characterized as below
as a new variety.)

Only one dorsal valve of this shell occurs in the collection. Its general form and surface
characters are very much like those of Micromitra (Paterina) labradorica swantonensis (Walcott)
[Pl. II, figs. 3, 3a-f]. The varietal name is given more on account of the fact that this shell
occurs in China and the variety swantonensis on the eastern side of the North American con-
tinent than from any marked differences between the shells from the two localities. It may
be that with a good series of shells from China differences would be found that are not to be
determined with only the single shell for comparison.

FORMATION AND LOCALITY.—Middle Cambrian: (C9) Lower limestone member of the Kiulung group [Blackwelder,
1907a, pp. 37 and 39 (8d list of fossils)], 3 miles (4.8 km.) southwest of Yenchuang, Sintai district, Shantung, China.

Micromirra (PATERINA) LABRADORICA SWANTONENSIS (Walcott).

Plate II, figures 3, 3a-f.

Kutorgina labradorica Waxcorr (in part) [not (Bruines)], 1886, Bull. U.S. Geol. Survey No. 30, Pl. IX, figs. 2, 2a-b.
(The text reference [on page 104] includes only specimens belonging to the species Micromitra (Paterina) labra-
dorica. The figures represent specimens of the variety swantonensis, which are redrawn in this monograph,
Pl. I, figs. 3, 3a-b, respectively.) tote \

Kutorgina labradorica swantonensis Waucorr, 1890, Proc. U. S. Nat. Mus. for 1889, vol. 12, p. 36. (Characterized as
a new variety.)

Paterina labradorica BrEcuEr [not (Brotrnes)], 1891, Am. Jour. Sci., 3d ser., vol. 41, footnote, pp. 345-346, Pl. XVII,
figs. 1 and 2. (Discussed as the type of the new genus Paterina. Figs. 1 and 2 are copied from Walcott’s
ficures, 1886b, Pl. IX, figs. 2b and 2, respectively.)

Kutorgina labradorica swantonensis Waucorr, 1891, Tenth Ann. Rept. U. 8. Geol. Survey, p. 609, Pl. LXIX, figs.
2, 2a-b. (Characterized. Figs. 2, 2a-b are copied from Walcott, 1886b, Pl. IX, figs. 2, 2a-h.)

Paterina labradorica Haut and Crarxe [not (Bmirnes)], 1892, Eleventh Ann. Rept. State Geologist New York for 1891,
p. 247, fig. 258. (Genus Paterina described. Fig. 258 is copied from Walcott, 1886b, Pl. IX, figs. 2b and 2a.}

Iphidea bella Harn and Crarxe [not Bruines], 1892, idem, p. 249, Pl. IV, figs. 4 and 5. (Mentioned.)

—

PATERINIDA. 349

Iphidea bella Hatt and Cuarks (in part) [not Brnrrnes], 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, p. 98,
Pl. IV, figs. 8 and 9 (not fig. 54, p. 98, which is referred in this monograph to Micromitra (Paterina) bella). (Men-
tioned in the text. Figs. 8 and 9 are copied from Hall and Clarke, 1892a, Pl. IV, figs. 4 and 5, respectively.)

Tphidea labradorica ScuucHERt (in part) [not (Brmines)], 1897, Bull. U. 8S. Geol. Survey No. 87, p. 234. (Accepts
Billings’s reference of ‘‘Obolus labradoricus” to Iphidea, but includes reference to specimens of both Micromitra
(Paterina) labradorica and its variety swantonensis.) :

Iphidea labradorica swantonensis (Walcott), ScHucHERT, 1897, idem, p. 234. (Merely changes generic reference.)

Iphidella labradorica swantonensis Waucorr, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 307. (Merely changes generic
reference.)

Iphidea swantonensis (Walcott), GrRaBAU and Sumer, 1907, North American Index Fossils, vol. 1, p. 201, figs. 2341
and 234j, p. 199. (Described. Figs. 2341 and 234] are copied from Walcott, 1886b, Pl. IX, figs. 2a and 2b,
respectively.)

The general form of the two valves of this variety is so close to that of Icromitra (Paterina)
labradorica (Billings) (p. 347) that it will not be necessary to repeat the description. The dif-
ferences existing in the variety swantonensis have been mentioned in describing the species.
The variety is exceedingly abundant in the Olenellus-bearing limestone, 2 miles (3.2 km.) east of
Swanton, Vermont, in association with Kutorgina cingulata (Billings). Shell substance corneous.

The most interesting addition to our knowledge of the species is the discovery of the
presence of a narrow area on the ventral valve and a short pseudodeltidium, as shown in a
longitudinal section (PI. II, figs. 3ce-f). The existence of the area and pseudodeltidium in the
ventral valve of the variety swantonensis, the form studied by Beecher, and in the dorsal valve
of M. (P.) labradorica, was unknown at the time that Beecher [1891, p. 345] selected I. (P.)
labradorica swantonensis (see p. 344) as the simplest form or prototype (Paterina), ‘‘preserving
throughout its development the main features of a protegulum, and showing no separate or
distinct stages of growth.”

The discovery of the area and pseudodeltidium refers the species and its varieties to the
genus Micromitra [Walcott, 1897b, p. 707].

The exact stratigraphic position of Locality 87 has not been made out, but from the
associated species of Agnostus and Ptychoparia, it is evidently to be referred to the Middle
Cambrian.

This form owes its varietal name to its occurrence in the vicinity of Swanton, Vermont.

FoRMATION AND LOCALITY.—Middle Cambrian: (87) Conglomeratic limestone 1 mile (1.6 km.) south-southwest
of Highgate Falls, Franklin County, Vermont.

Lower Cambrian: (25a) Limestone on the Hall (Donaldson’s) farm, 2 miles (3.2 km.) east of Swanton; (819z) sandy
limestone 2.5 miles (4 km.) east of Swanton; (26) sandstone northeast of the Corman farm buildings, east of Highgate
Springs; .and (319y) sandstone 2 miles (3.2 km.) east-southeast of Highgate Springs; all in Franklin County, Vermont.

(319x) Limestone at the crossing of Hast Creek and Grove Street, 1.25 miles (2 km.) north of Rutland, Rutland
County, Vermont.

MicromitrRA (PATERINA) LABRADORICA UTAHENSIS (Walcott).

Text figure 24, page 350; Plate II, figures 8, 8a.
Iphidella labradorica utahensis Waucotr, 1905, Proc. U. 8. Nat. Mus., vol. 28, p. 306. (Characterized as a new variety.)

The general form of this variety is much like that of Micromitra (Paterina) labradorica
(Billings). It differs from it in the fine, threadlike, concentric strie of the outer surface, in
this respect approaching IM. alabamaensis (Walcott) and M. (P.) superba (Walcott). During
the field season of 1906 fine specimens of this variety were found in the limestones 760 and
1,200 feet above the quartzitic sandstones referred to the Lower Cambrian. A ventral valve
6 mm. in width has a convex pseudodeltidium 1.25 mm. in length, with a width of 2.5 mm. at

its slightly arched margins. The variety swantonensis also has a wide, convex pseudodeltidium
(PI. II, figs. 8e, 3f).

FoRMATION AND LOcALITY.—Middle Cambrian: (30c) About 1,050 feet (320 m.) above the Lower Cambrian and
3,350 feet (1,021.1 m.) below the Upper Cambrian in the shales forming 1d of the Swasey formation [Walcott, 1908f,
p. 182], at the head of Dome Canyon, House Range [Walcott, 1908f, Pl. XIII], Millard County; (3d) concretionary lime-
stone about 100 feet (30.5 m.) above the quartzitic sandstones of the Cambrian, at Ophir, Oquirrh Range, Tooele
County; (30p) about 125 feet (38 m.) above the Cambrian quartzitic sandstones, on the north side of Ogden Canyon,

350 CAMBRIAN BRACHIOPODA.

about 1 mile (1.6 km.) above its mouth, east of Ogden, Weber County; (80u) about 250 feet (76.2 m.) above the top of
the Cambrian quartzitic sandstones, in sandy shales, 4 miles (6.4 km.) northwest of Promontory Point (on the
“Tjucin cut-off” of the Union Pacific Railway), about halfway
up west end of ridge, north of Great Salt Lake, Boxelder County;
(34m) limestone about 765 feet (233.2 m.) above the Brigham
quartzite [Walcott, 1908a, p. 8], 1 mile (1.6 km.) northwest of
Geneva (Copenhagen), east of Brigham, Boxelder County; and
(32d) shales about 150 feet (45.7 m.) above the Brigham quartz-
ite [Walcott, 1908a, p. 8], on the east side of the south fork of
Paradise Dry Canyon (locally known as East Fork), east of Par-
adise, Cache Valley, Cache County; all in Utah.

us (54a) About 750 feet (228.6 m.) above the Brigham quartzite |

FIGURE 24.— Micromitra (Paterina) labradorica utahensis (Wal- and 3,440 feet, (1,048.5 m.) below the Upper Cambrian in the
cott). A, A’, A”, Top, side, and back views ofaventralvalve shales forming 2a of the Ute limestone [Walcott, 1908f, p. 196];
PU ace SE eG © aan Ga (540) about 900 feet (274.3 km.) above the Brigham quartzite
5184). Soeeat cent Hea Loe Be NAB MNS ESS and 3,300 feet (1,005.8 m.) below the Upper Cambrian in the

- limestone beds forming 1b of the Ute limestone [Walcott, 1908f,

p. 196]; and (54m) about 1,225 feet (373.4 m.) above the Brigham quartzite and 2,950 feet (899.2 m.) below the Upper Cam-

brian in the upper part of the limestone forming 1a of the Ute limestone [ Walcott, 1908f, p. 195]; allin Blacksmith Fork

Canyon, about 10 miles (16.1 km.) east of Hyrum, Cache County, Utah.

Micromitra (PATERINA) LABRADORICA var. undt.

This form is distinguished from Micromitra (Paterina) labradorica (Billings) and its varie-
ties by having much finer and more closely arranged concentric striz. In other characters it
approaches very closely to the typical forms of the species.

ForMATION AND LOCALITY.—Lower Cambrian: (1v) Shales of No. 3 of the Silver Peak group, Barrel Spring section

[Walcott, 1908f, p. 189], 3 miles (4.8 km.) north of Valcalda Spring and 4 miles (6.4 km.) west-northwest of the Drink-
water mine, Silver Peak quadrangle (U. S. Geol. Survey), Esmeralda County, Nevada.

Micromirra (PATERINA) LOGANI (Walcott).
V Plate II, figures 6, 6a—b.

Iphidea logani Watcorr, 1897, Proc. U: S. Nat. Mus., vol. 19, pp. 711-712, Pl. LIX, figs. 2, 2a-b. (Described and
discussed essentially as below as a new species. The specimen represented by figs. 2, 2a-b is redrawn in this
monograph, Pl. II, figs. 6, 6a—b.)

Ventral valve conical, transverse in outline at the base, almost semicircular. Beak minute,
incurving over the pseudodeltidium. Cardinal slopes rounded and flattened so as to form a
fairly well-defined false area that is broken by a very wide triangular space. Pseudodeltidium
arching upward, forming a narrow, sloping shelf beneath the beak, the angle of slope from the
summit of the shell over the beak and pseudodeltidium being nearly the same as the slope from
the summit to the front.

Surface marked by very fine concentric striz and somewhat coarser lines of growth. Under
a high power slight traces of radiating strix may be observed. The concentric striz pass around
over the false area and cross the pseudodeltidium. Shell substance corneous.

Observations.—This specimen was received from Whiteaves, of the Geological Survey of
Canada, as the type of M. (P.) bella (Billings). It differed, however, so materially from the
description of that species [Billings, 1872b, pp. 477-478] and the figure illustrating it that i
found it necessary to give it a distinct specific designation. (See pp. 335 and 345.)

This species approaches most nearly M. (P.) crenistria (Walcott) in its short pseudodel-
tidium and finely striated surface. It differs, however, in the character of the surface striz,
the form of the false area, and the pseudodeltidium.

The specimen bears the label “Trois Pistoles, 1868, T. C. Weston.” It was collected from
a bowlder in the conglomerate at that locality, and it is probably of Middle Cambrian age, though
this can not be stated positively, as there are no associated fossils. Billings [1872b, p. 478]
speaks of the occurrence of fragments of trilobites in the bowlder containing his type of Micro-
mitra (Paterna) bella. He does not mention the genera or species.

PATERINIDA. B51

The conglomerates of this formation, according to Logan, form 9 separate layers, from 2
to 16 feet thick, bedded in gray calcareous sandstone. The geologic age of the deposit of the
matrix is supposed to be Upper Cambrian or Lower Ordovician. The age of the bowlders can
only be determined by the fossils found in each.

The specific name was given in honor of Sir William EH. Logan.

FoRMATION AND LocALIty.—Middle? Cambrian: (2n) Limestone in conglomerate on shore near Trois Pistoles,
on St. Lawrence River, Province of Quebec, Canada.

Micromirra (PATERINA) MAJOR (Walcott).

Text figure 25.

Iphidella major Waucorr (in part), 1905, Proc. U. 8. Nat. Mus., vol. 28, p. 304. (Described and discussed somewhatas
below as a new species. Specimens now referred to Micromitra (Paterina) williardi were included with the
specimens representing Micromitra (Paterina) major when this description was given.)

Obolus smithi Waxcorr (in part), 1908, Smithsonian Misc. Coll., vol. 53, No. 3, Pl. VII, fig. 9 (not fig. 9a, which rep-
resents a specimen of Obolus smithi). (No text reference. Fig. 9, which is reproduced in this monograph as
fig. 25, was inserted on Pl. VII of the above reference by mistake. All of the figures representing the two species
(Obolus smithi and Micromitra (Paterina) major) happened to be grouped on the same preliminary plate, and
when two figures were chosen to represent Obolus smathi in the paper referred to, one of the figures representing
Micromitra (Paterina) major was accidentally included.)

Ventral valve subconical, with the apex slightly in front of the posterior margin. <A
minute beak appears to incurve over the pseudodeltidium. Cardinal slope
rather abruptly rounded, so as to indicate a rather narrow false area.
Pseudodeltidium broad and convex, with its lower margin arched so as to
leave a space between it and the plane of the margin of the shell. Dorsal
valve slightly convex, with a narrow area.

Surface, so far as can be determined from the badly preserved mate- peown25— Gn et
rial, marked by rather strong growth lines and very fine concentric striz. — (Paterina)_major (Wal-
The largest dorsal valve has a length of 10.5 mm.; width, 13mm. Only Cot. Patoliated dorsal

valve from Loeality 56ce,

one small ventral valve is known. Lower Cambrian beds in
Ob oe Th “all ine Ale o o 1 Rome formation (‘‘Mon-
servations.—The material representing this species is more or less _ teyatloshale”),1.125 miles

compressed and distorted in the argillaceous shales m which it occurs. 8 km.) northeast of
te} Helena, Shelby County,

In general form it is not unlike that of Micromitra (Paterina) labradorica Alabama (U. S$. Nat.

(Billings) (PI. II, figs. 2, 2a-f), but it differs in its nearly smooth surface — Mus: Cat. No. 51490).6
‘e This figure was published

and the position of the apex. It is, however, the southern Appalachian | twaicott,1908a, Pi. VII, fig.

< 5 noe 5 S S | - 9] as representing the dorsal
representative of that species. The original description of this species was Se enn and

based on specimens now referred to this species and to Micromitra (Pater- was given Cat. No. 51611a.
P ‘Ti ah WwW Theat Vv al : Bh Tip Hit ae all As explained in the note
ina) williardy Walcott. Very good specimens of the latter are now avail- \naer the second reference
able from two localities near Helena, Alabama. Jin WAS S\yatomnanhy, HAS Wes

: : . : . a mistake.
This form owes its specific name to its large size.

FORMATION AND LOCALITY.—Lower Cambrian: (56c) Rome (‘‘ Montevallo”’) formation along road just north of Buck
Creek, 1.125 miles(1.8 km.) northeast of Helena; and (17b) Rome (‘‘Montevallo”) formation 4 miles (6.4 km.) south of
Helena; both in Shelby County, Alabama.

A dorsal valve similar to the one illustrated above occurs at the following locality:

Middle Cambrian: (90) Conasauga (‘Coosa’) shale on Edward’s farm, near Craigs Mountain, about 10 miles (16.1
km.) southeast of Center, Cherokee County, Alabama.

Micromitra (PATERINA) PHILLIPSI (Holl).
WA Plate ITI, figure 8.

Obolella phillipsi Hout, 1865, Quart. Jour. Geol. Soc. London, vol. 21, pt. 1, p. 102, figs. 10a-c. (Described as a new
species. The specimen represented by figs. 10b and 10c is redrawn by Davidson, 1866, Pl. IV, figs. 17a and 17c,
and Davidson’s figures are copied in this monograph, Pl. III, fig. 8.)

Obolella ? phillipsi Holl, Davipson, 1866, British Fossil Brachiopoda, vol. 3, pt. 7, No. 1, pp. 62-63, Pl. IV, figs. 17-19.
(Described and discussed. Figs. 17a and 17c are drawn from the specimen represented in figs. 10b and 10c of
the preceding reference, and are reproduced in this monograph, Pl. III, fig. 8.)

Kutorgina cingulata Davison [not (Bixxines)], 1868, Geol. Mag., vol. 5, p. 312, Pl. XVI, fig. 10. (Discussed.)

302 CAMBRIAN BRACHIOPODA.

EKutorgina cingulata Davison [not (Britrnes)], 1871, British Fossil Brachiopoda, vol. 3, pt. 7, No. 4, pp. 342-343,
Pl. L, fig. 25. (Discussed. Fig. 25 is copied from fig. 10 of preceding reference (p. 351) and erroneously referred
to in the description of Pl. L as ‘‘Kortugina eingulata.”’)

Obolella phillipsi Holl, Pures, 1871, Geology of Oxford and the Valley of the Thames, p. 68, Diagram XVII, fig. 12..

(No text reference.)

Obolellus ? phillipsi (Holl), RonmeEr, 1876, Lethzea geognostica, pt. 1, Lethzea paleeozoica, atlas, Pl. Il, figs. 6a-d. (No
text reference. Figs. 6a—d are copied from Davidson, 1866, Pl. IV, figs. 19, 17a, 17c, and 17h, respectively.)

Obolella phillipsia Holl, Dauu, 1877, Bull. U. S. Nat. Mus. No. 8, p. 41. (Mentioned as possibly belonging to an
undescribed genus.) ;

Kutorgina cingulata Daviwson [not (Bratrnes)], 1883, British Fossil Brachiopoda, vol. 5, pt. 2, p. 212. (Characterized.)

Kutorgina cingulata Waucorr (in part) [not (Brtnes)], 1886, Bull. U. 8. Geol. Survey No. 30, pp. 102-104. (Speci-
mens now referred to Micromitra (Paterina) phillipsi were included with the specimens representing Kutorgina
cingulata when this description was written.)

Kutorgina cingulata phillipsi (Holl), Matiey, 1902, Quart. Jour. Geol. Soc. London, vol. 58, pt. 1, pp. 145-147.
(Described and discussed as a variety.)

The original description by Holl follows:

Semicircular, slightly broader than long; hinge-line straight, nearly equal to the greatest width of the shell.
Ventral valve prominent at the beak, depressed near the margin; beak small, round, pointed, and situated close to the
posterior margin. Dorsal valve evenly convex, slightly depressed at the angles; umbo obtuse. A slight mesial depres-
sion toward the anterior border in both valves. Surface marked with numerous moderately fine, sharply defined,
rather unequal, concentric striz, at about their own width apart. Length-of a large specimen one-fourth inch, width
one-third inch.

The shell structure, where the outer layer has become exfoliated, is strongly punctate.

Observations.—Davidson [1868, p. 312] refers this form to Kutorgina cingulata (Billings)
under the belief that the American and English species occur at the same relative geologic
horizon. The American species, however, occurs in association with the Olenellus fauna.
With the identification of the types of Kutorgina cingulata (Billings) and Kutorgina labradorica
(Billings), the latter species being referred to Micromitra (Paterina), it is no longer possible to
refer Holl’s species to Kutorgina cingulata, it being clearly congeneric with Micromitra (Paterina)
labradorica. It differs specifically from that species in a more depressed ventral valve.

The specific name was given in honor of Mr. J. Phillips.

ForMATION AND LOCALITY.—Upper Cambrian: (304g [Holl, 1865, p. 89]) Sandstones of the Hollybush series, Mal-
vern Hills, between Herefordshire and Worcestershire, England.

Lower Cambrian: (304c) ‘‘Malvern quartzite’ at Raggedstone Hill; and (304d) ‘‘Malvern quartzite’’ at Mid-
summer Hill; both [Groom, 1902, p. 94] in the Malvern Hills, between Herefordshire and Worcestershire, England.

Micromitra (PATERINA) PROSPECTENSIS (Walcott).
Plate II, figures 4, 4a.

Kutorgina prospectensis Waucort, 1884, Mon. U. 8. Geol. Survey, vol. 8, p. 19, Pl. IX, figs. 1, la-b. (Described as a
new species. The specimens represented by figs. 1, la—b are redrawn in this monograph, Pl. II, figs. 4a and 4,
respectively.)

Kutorgina prospectensis Watcorr, 1886, Bull. U. S. Geol. Survey No. 30, pp. 106-107, Pl. IX, figs. 3 and 3a. (Copies
original description and discusses species. Figs. 3 and 3a are drawn from the specimens figured by Walcott,
1884b, Pl. IX, figs. la and 1, respectively.)

Kutorgina prospectensis Watcort, 1891, Tenth Ann. Rept. U.S. Geol. Survey, p. 610, Pl. LXIX, figs. 4and 4a. (Men-
tioned. Figs. 4 and 4a are copied from Walcott, 1886, Pl. IX, figs. 3 and 3a, respectively.)

Iphidea prospectensis (Walcott), ScHucHERT, 1897, Bull. U.S. Geol. Survey No. 87, p. 234. (Merely changes generic
reference.)

Iphidella prospectensis Waucort, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 307. (Merely changes generic reference.)

Ventral valve subconical, moderately elevated.

Dorsal valve moderately convex, the beak curving down to the posterior margin. The
character of the area and pseudodeltidium is unknown. The surface slopes gently from the
front to the highest point of the valve and arches down to the point of the beak. There is no
trace of a mesial sinus. The cardinal slopes diverge from the beak at an angle of about 170°.
Shell substance corneous.

PATERINIDA. abe

The surface of both valves is marked by clearly defined, regular, concentric striz that are
slightly crenulated by striz radiating from the beak outward to the margin. The concentric
strie show 10 in a distance of 1 mm. and 8 at the center of the dorsal valve.

Observations.—-Nothing is known of the interior or the areas of either valve. The clearly
defined concentric strix, the thick corneous shell, and the long convex pseudodeltidium dis-
tinguish the species from all others of the genus known to me, with the possible exception of
Micromitra (Paterina) labradorica swantonensis (Walcott). In the latter species, however, the
strie are less regular, and present quite a different appearance under the magnifier. In the
original description [Walcott, 1884b, p. 19] the comparison was made with Kutorgina cingulata
(Billings) as to certain points of resemblance between J. (P.) prospectensis and. the young
shells of K. cingulata.

This form owes its specific name to its occurrence on Prospect Mountain in the Hureka
district, Nevada.

FORMATION AND LOCALITY.—Lower Cambrian: (1m and 1p) Limestones of No. 2 of the Silver Peak group, Barrel
Spring section [Walcott, 1908f, p. 189], about 2.5 miles (4 km.) south of Barrel Spring and 0.5 mile (0.8 km.) east of
the road, in the extreme southeastern corner of the Silver Peak quadrangle (U.S. Geol. Survey), Esmeralda County;
and (52) arenaceous shales just above the Prospect Mountain quartzite, in a stratigraphic position similar to that of the Pioche

shale [ Walcott, 1908f, p. 184], at the top of Prospect Mountain, Eureka district | Hague, 1892, Atlas], Eureka County; both
in Nevada.

Wi Micromirra (PATERINA) STISSINGENSIS-(Dwight).

Plate III, figures 1, la-e.

Kutorgina stissingensis Dwicut, 1889, Am. Jour. Sci., 3d ser., vol. 38, pp. 145-147, Pl. VI, figs. 5-8. (Described and —
discussed as a new species; see below for copy of paragraph on p.146. The specimens represented by figs. 5, 6,
and 8 are redrawn in this monograph, Pl. III, figs. 1c, 1, and la, respectively.)

Kutorgina stissingensis Dwicut, 1891, Trans. Vassar Brothers’ Inst. for 1887-1890, vol. 5, pt. 2, p. 105, figs. 5-8, p.
108. (Described and discussed as a new spécies.)

Iphidea stissingensis (Dwight), ScHucHERT, 1897, Bull. U. S. Geol. Survey No. 87, p. 234. (Merely changes generic
reference.)

Iphidella stissingensis (Dwight), Watcorr, 1905, Proc. U. 8. Nat. Mus., vol. 28, p. 308. (Merely changes generic
reference.)

All the specimens of this species known to me are more or less compressed in an argillaceo-
arenaceous shale and impure limestone. As far as can be determined the ventral valve is
obtusely conical, with the apex slightly incurving.

Dwight [1889, p. 145] in his origimal description mentions the presence of a distinct false
area on the ventral valve, and I find in the two specimens traces of the area, also a wide, low,
slightly convex pseudodeltidium.

The dorsal valve appears to have been slightly convex and to have resembled closely the
general form and proportions of the same valve of Micromitra (Paterina) labradorica (Billings).
One somewhat crushed specimen shows a very low false area and a rather broad, low pseudo-
deltidium somewhat like that of M. (P.) labradorica. It is too imperfect, however, for detailed
description or illustration. Z

The surface of both valves is covered with very fine, sharp, slightly crenulated strie and
fine ridges of growth, crossed by very fine radiating strie and fine radiating undulations of
the same type as those in Micromitra sculptilis (Meek). The concentric strie cross the false
areas and pass over the pseudodeltidium. Shell substance corneous.

Dwight [1889, p. 146] describes the surface markings in detail as follows:

The concentric ridges are somewhat wavy as seen under a strong magnifier; they are semicircular; a number of
those lying nearest to the front margin run out along the upper part of the lateral margins, but the remainder and
larger number terminate in regular order along the cardinal border. In front of the central portions of the shell the
concentric ridges, which number about 12 to 15 to a millimeter, are regularly concentric; but nearer to the beak-the
number and the irregularity greatly increase. Ata point about one-third the length of the shell from the beak there
are 25 or more to the millimeter; as the radiating plications are numerous in this part, there is caused a complexity of

curves, which under a powerful magnifier produces the effect of elegant and delicate basketwork. The radiating
undulations are very irregular in position and number; they are not thoroughly continuous from the beak in specimens

62667°—vo1 51, pr 1—12——_-23

=

3D4 CAMBRIAN BRACHIOPODA.

observed, but appear at irregular intervals singly or in groups; while apt to be crowded around the beak, they are
rare near the front margin. On the best specimens about 25 have been counted in the central part of the shell just
forward of the beak; had they extended in equal distribution around it, quite to the cardinal border, there would
have been about 50. They are also unequal in breadth; where they are somewhat regular, the interspaces about
equal the plications in width; these plications are multiplied by implantation.

Observations—Some young specimens show a surface ornamentation very much like that
of Micromitra sculptilis (Meek) (Pl. IIL), but the ornamentation of the adult shell is quite
distinct. As stated by Dwight [1889, p. 147], fragments of the shell m the shale might be
taken for the shell of ‘‘Lingulepis pinniformis” (see Lingulella (Lingulepis) acuminata (Con-
rad), p. 545). He also calls attention to the general resemblance to Micromitra (Paterina)
labradorica (Billings).

Attention has been called under the description of MZ. alabamaensis (Walcott) (p. 337) to
the similarity of form and surface ornamentation between that species, If (P.) labradorica
(Billings), MZ. (P.) labradorica swantonensis (Walcott), and I. (P.) stissingensis.

An apparently identical form occurs at Mount Stephen, British Columbia, in association
with Ogygopsis klotzi (Rominger). It has the same outline and shows the variations of surface
ornamentation so characteristic of M. (P.) stissingensis (Dwight) from New York. The radial
markings are lightly impressed and are so often entirely obscured that the Mount Stephen
form frequently resembles the form described under the name of Micromitra zenobia (p. 342).

This form owes its specific name to its occurrence near Stissing, New York.

FoRMATION AND LOCALITY.—Middle Cambrian: (367d [Dwight, 1889, p. 145]) Limestone near Stissing, Dutchess
County, New York.

A single specimen of a dorsal valve 3 mm. in width, that is apparently identical with shells
of similar size from the type locality, occurs at the following locality:

Middle Cambrian: (11m) Drill cores of limestone in the Bonneterre limestone at horizons 10 and 20 feet (3 and
6 m.) above the Lamotte sandstone, St. Francois County, Missouri.

Apparently identical forms occur at the following locality:

Middle Cambrian: (14s) About 2,300 feet (701 m.) above the Lower Cambrian and 2,700 feet (823 m.) below the’
Upper Cambrian, in the Ogygopsis zone of the Stephen formation [Walcott, 1908f, p. 210], at the “fossil bed” on the
northwest slope of Mount Stephen, above Field, on the Canadian Pacific Railway, British Columbia.

lV MicROMITRA (PATERINA) STISSINGENSIS ORA N. var.

This form is distinguished from the specimens tentatively referred to Micromatra (Patervna)
stissingensis on Mount Stephen and from the typical specimens of the latter species in New
York by its uniformly larger size and in its distinct radial striation. The Mount Stephen
representatives of J. (P.) stissingensis frequently betray so little evidence of radial striation
that they resemble Micromitra zenobia, a form which is associated with IM. (P.) stissingensis
ora and which differs from the latter variety in the entire absence of radial striation. It is
possible that the Canadian forms will prove to be distinct from the New York species. Nothing
is known of the cardinal area or pseudodeltidium of Jf (P.) stissingensis ora.

ForMATION AND LOCALITY.—Middle Cambrian: (35k) Shales in the Stephen formation on the west slope of the
ridge between Mount Field and Wapta Peak, 1 mile (1.6 km.) northeast of Burgess Pass, above Field, British Columbia.

Micromirra (PATERINA) STUARTI Walcott.
Text figures 26A—B, page 359.

Micromitra (Paterina) stuarti Waxcott, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, p. 58, Pl. VII, figs. 8 and 8a.
(Described and discussed as below as a2 new species. Figs. 8 and 8a are copied on page 355, figs. 26A and 26A”,
respectively.)

Ventral valve subconical, with a minute beak arching slightly over a short pseudodeltidium.
Cardinal slope with a rounded angle that extends from the beak to the posterolateral margin
and defines a.very narrow, flattened area on each side of a high triangular fissure that is covered
for a short distance at the top by a very short, arched pseudodeltidium.

PATERINIDA. 355

Dorsal valve rather strongly convex for a species of this genus; the highest part is at
about the center of the shell, from whence the slope is very slight to the beak, and rather rapid

to the front margin.
Beak marginal above
a low, broad arching
of the posterior mar-
gin of the shell; area
shown only by a very
narrow margin where
the shell bends toward

the median line; no

a UW del- FIGURE 26.— Micromitra (Paterina) stuarti Walcott. A, A’, A”, Top, side, and back views of ventral valve,
or mice of ee pss do the type specimen (U.S. Nat. Mus. Cat. No. 51485a). B, B’, Top and side of dorsal valve (U.S. Nat.
tidium has been ob- Mus. Cat. No. 51485b).

served. The specimens represented are from Locality 54n, Middle Cambrian limestones in Blacksmith Fork Can-
S rf k 1 yon, east of Hyrum, Cache County, Utah. qBigures 26A and 26A/’ are copied from Walcott [1908d, Pl. VII,
urface Markec figs. § and 8a].

by narrow, rounded,
concentric threadlike striz or ridges with short striz between them. Shell substance corneous.

The average size of adult shells is 8 mm. long by about the same width.

Observations.—This is one of the larger species of the genus. Micromitra (Paterina) superba
(Walcott) occurs 16 feet (4.5 m.) below and Micromitra U[phidella) pannula (White) 70 feet
(21.3 m.) below in the same section.

This fine shell has a short pseudodeltidium much like that of M. (P.) logan (Walcott),
but it differs in form and greater size; the same is true of M. (P.) crenistria (Walcott). It
may be closely related to M. (P.) labradorica utahensis (Walcott), but the specimens of the
latter are too imperfect for close comparison of form.

The specific name is given for my son, Benjamin Stuart Walcott, who assisted me in col-
lecting the specimens during the summer of 1906.

ForRMATION AND LOCALITY.—Middle Cambrian: (54n) About 550 feet (167.6 m.) above the Brigham quartzite

and 3,640 feet (1,109.5 m.) below the Upper Cambrian, in the limestones forming 2e of the Ute limestone [Walcott,
1908f, p. 197], in Blacksmith Fork Canyon, about 10 miles (16.1 km.) east of Hyrum, Cache County, Utah.

MicromitrRA (PATERINA) SUPERBA (Walcott).
We Text figures 27A—B; Plate II, figures 7, 7a-t.

Iphidea cnt.” ornatella Hai and CuarKe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, Pl. IV, figs. 6 and 7.
(No text reference.)
Iphidea swperba Waxcort, 1897, Proc. U. S. Nat. Mus., vol. 19, p. 711, Pl. LIX, figs. 1, la-c. (Described. The speci-
mens represented by figs. 1, la-c are redrawn in this monograph, PI. II, figs. 7c, 7, 7a, and 7b, respectively.)
Ventral valve subconical, with a minute beak incurving over the pseudodeltidium. Car-
dinal slope slightly flattened so as merely to indicate an imperfectly defined rather narrow
false area. In some specimens
the curvature of the shell is
practically continuous to the
base of the pseudodeltidium.
Pseudodeltidium broad, con-
vex, with its lower margin
broadly arched, so as to leave

é a considerable space between
IGURE 27.— Micromitra (Paterina) superba (Walcott). A, A’, Top and back views of ventral ; 7 ; >
valve from Locality 54n, Middle Cambrian limestones in Blacksmith Fork Canyon, Cache 1b and the line of the Semen al
County, Utah (U. S. Nat. Mus. Cat. No. 51486). B, Side view of ventral valve showing plane of the shell.
pseudodeltidium, from Locality 54y, at the same locality but from a slightly lower horizon “5 ‘ =
than that of the specimen represented by figures 27A-A’(U. S. Nat. Mus. Cat. No. 51491). Dorsal valve slightly Cone
vex; most elevated a little in

front of the small beak which projects a little over the broad open space beneath it. No traces
of a false area or pseudodeltidium have been observed.

356 CAMBRIAN BRACHIOPODA.

Surface with rather strong concentric strie, and a few somewhat obscure lines of growth.
On the ventral valve the striae extend around to and cross the pseudodeltidium. Shell sub-
stance corneous.

Observations.—This is one of the larger species of the genus, being surpassed in size only
by Micromitra (Paterina) labradorica (Billings). It is clearly distinguishable from J. (P.)
bella (Billings) by its larger size, more depressed ventral valve, and the form of the pseudo-
deltidium. The dorsal valves of the two species are quite similar. It differs from M. pealei
(Walcott) in its broad pseudodeltidium, false area, and surface markings.

One specimen has a length of 9 mm. and a little greater width. The area is vertical, the
pseudodeltidium being broken away.

This species is represented by some fine specimens that occur in the lower part of the
Middle Cambrian of northern Utah. Micromitra ([phidella) pannula (White) occurs 54° feet
(16.5 m.) lower in the section and M. (Paterina) stuarti Walcott 16 feet (4.5 m.) higher up.:

FORMATION AND LOCALITY.—Middle Cambrian: (74) Sandstone about 300 feet (91.4 m.) above the base of the
Tonto group, at the head of Nunkoweap Valley; (74d) sandstone beds in “‘ Tonto” shale, just above massive sandstones
near mouth of Bass Canyon, on the south side of the Grand Canyon; and (78a) ‘“‘Tonto”’ sandstone in Chuar Valley;
all in the Grand Canyon of the Colorado, Arizona.

(54n) About 550 feet (167.6 m.) above the Brigham quartzite and 3,640 feet (1,109.5 m.) below the Upper Cam-
brian in the limestone forming 2e of the Ute limestone; (54p) about 525 feet (160 m.) above the Brigham quartzite
and 3,665 feet (1,127.1 m.) below the Upper Cambrian in the shale forming 2f of the Ute limestone; and (54y) about
510 feet (155.4 m.) above the Brigham quartzite and 3,680 feet (1,121.7 m.) below the Upper Cambrian in the lime-
stones forming 2¢ of the Ute limestone; all in Blacksmith Fork Canyon [Walcott, 1908f, p. 197], about 10 miles (16.1
km.) east of Hyrum, Cache County, Utah.

(8j) About 575 feet (175.3 m.) above the unconformable base of the Cambrian in a shale which corresponds in
position to shale No. 4 of the Dearborn River section [Walcott, 1908f, p. 202], on the ridge between Gordon and Youngs
creeks, about halfway between Gordon Mountain and Cardinal Peak, Ovando quadrangle (U.S. Geol. Survey),
Powell County, Montana.

Specimens that are somewhat doubtfully identified with this species occur in the following
locality:

Upper Cambrian: (160) Sandstones forming a remnant of the Gallatin formation, which lies between the expo-
sures of “ porphyrite” on the east side of Willow Creek [Peale, 1896, areal geology sheet], 12 miles (19.2 km.) south-
southwest of Threeforks, Threeforks quadrangle (U. 8S. Geol. Survey), Gallatin County, Montana.

Micromirra (PaTEerRinA) UNDoSA (Moberg).
Text figures 28A—C.

Kutorgina undosa Mosere, 1892, Geol. Foren. i Stockholm Forhandl. for 1892, Bd. 14, Hit. 2, p. 112, Pl. III, figs.
10-12. (Described in Swedish as a new species; see below for free translation. Figs. 10-12 are copied in this
monograph as figs. 28C, 28A, and 28B, respectively.)

Moberg describes this form essentially as follows:

No specimen shows the umbonal part of the ventral shell completely preserved, yet it seems as if the umbo had
projected somewhat beyond the straight hinge margin. From the umbo the shell slopes gently in all directions,
forming a rather feebly convex surface with even arch. The dorsal
valve is more flattened and less evenly arched than the ventral
and more transverse, with the anterior corners evenly rounded off.
The area is not quite distinctly preserved on any specimen; the
beak is situated quite near the posterior edge; it is sharply marked
A,B, and projects with a somewhat blunt point. The ornamentation of

FIGURE 28.— Micromitra (Paterina) undosa (Moberg). : oe :
Ventral valves. C, Dorsal valve. the shell is very characteristic; the strongly marked lines of growth

The specimens represented by figures 28A and 28B are appear to be formed of a row of small bows, and on some specimens
from Locality 390a, drift blocks of LowerCambriansandstone there are fine, short, sharp, radiating, subordinate, depressed lines.

at Stora Rér, Oeland Island; that represented by figure 28C The shell is quite thick, and, it is thought, formed of a hornlike
is from Locality 390h, drift blocks of Lower Cambrian sand-

stone on Nordmannaskiir Island; both in Sweden. Figures substance.

28A-C are copied from Moberg [1892, Pl. III, figs. 11,12, A a 5 1

and 10). Figure 28B may be selected as representing the Two specimens of medium size are 4 mm. and 3.5
type specimen. mm. long and 5 mm. and 4.75 mm. broad, respectively.

Judging by the fragments the species must have attained considerable size.

PATERINIDZ. 357

Observations. —This form recalls Micromitra (Paterina) labradorica (Billings), which is found
in association with Discinella at Bic, Canada. The size and character of the shell indicate its
relationship to Micromitra rather than to Kutorgina.

FoRMATION AND LOCALITY.—Lower Cambrian: With Discinella in drift blocks of glauconitie quartzitic sand-
stone at the following localities [Moberg, 1892b, pp. 112 and 115]; (310f) west of Ekerum; (390a) at several points
near Stora Rér; (390d) north of Rohilla; and (390h) on Nordmannaskar Island; all in the Kalmar district of the
Geological Survey of Sweden, Oeland Island, Sweden.

Moberg [1892b, p. 114] describes some fragments which he refers to Kutorgina sp. From
his statement that the fragments appear to be of a horny texture it is highly probable that
they belong to the genus Micromitra.

Micromirra (PATERINA) wApTa Walcott.

Text figures 29A—B.

Micromitra (Paterina) wapta Waxtcort, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, p. 59, Pl. VII, fig. 6. (Described
and discussed as below as a new species. Fig. 6 is copied in this monograph as fig. 29A.)

Shell large and thick for a species of this genus. Ventral valve depressed, conical, with
the apex above a narrow false area that is outlined by the abrupt curvature of the shell. As
the shells usually occur compressed in the siliceous shale,
the false area is concealed and the posterior slopes from
the apex form a blunt angle at the apex. Dorsal valve
transverse, moderately convex, with the posterior margin
nearly straight and a little shorter than the greatest
width of the valve; beak small, marginal; cardinal slope
and false area unknown.

Surface marked by concentric, slightly irregular,
rounded lines and ridges of growth that are grouped in

: 5 cee < hee FIGURE 29.— Micromitra (Paterina) wapta Walcott. A,
bands of varying width; a few radiating striz or lines Exterior of ventral valve, the type specimen (U.S. Nat.

Mus. Cat. No. 51402a). B, Portion of dorsal valve(U.S.

occur on the central portions of one ventral valve; with yf" tus. cat, No. 514020),

a lens magnifying 20 diameters an occasional roughness gy. specimens represented are from Locality 350, a
can be seen in reflected light on the surface of some of _ «rift block of Lower Cambrian shale on Mount Bosworth,
the concentric ridges. British Columbia. gure 29A is copied from Walcott
t=) [1908d, Pl. VII, fig. 6].
Observations.—This is one of the largest species of
the genus. One ventral valve has a length and breadth of 14 mm.; several are 9 to 11 mm. in
diameter. It compares in size with Micromitra (Iphidella) nyssa, from the same geologic hori-
zon in Montana, but the latter has a reticulate exterior surface of the If. U/.) pannula type. It
was at first thought that this species might be the old shells of Acrothele colleni Walcott, but
a careful comparison with the younger stages of growth of M. (P.) wapta shows that the latter
has only very indefinite traces of the highly ornate surface of Acrothele colleni and that the
apex of the ventral valve of J. (P.) wapta is imperforate and over the posterior margin and not
on the general surface of the valve in advance of the margin, as in Acrothele collent. The two
species were found associated on Mount Bosworth. JM. (P.) wapta is of the same type as MV.
(P.) labradorica, M. (P.) prospectensis, and M. (P.) stissingensis. It differs from all in having
more irregular, less definite threadlike concentric lines, and in the manner in which the striz
are assembled in ridges.
The specific name is derived from Lake Wapta, which les a little to the west of the type

locality.
: FORMATION AND LOCALITy.—Lower Cambrian: (35¢) Drift blocks of siliceous shale supposed to have come from the

Mount Whyte formation [ Walcott, 1908f, p. 214], found on the south slope of Mount Bosworth, a short distance northwest of
the Canadian Pacific Railway track between Stephen and Hector, eastern British Columbia, Canada.

(35e) About 270 feet (82.3 m.) below the Middle Cambrian, in a greenish siliceous shale correlated with No. 3 of
the Mount Whyte formation on Mount Bosworth [Walcott, 1908f, p. 214], in the amphitheater between Popes Peak
and Mount Whyte, about 3 miles (4.8 km.) northwest of Lake Louise, southwest of Laggan on the Canadian Pacific
Railway, Alberta, Canada.

358 -CAMBRIAN BRACHIOPODA.

\ Micromirra (PATERINA) WILLIARDI Walcott.

Text figures 30A—E; Plate II, figures 9b-c.”

Iphidella major Waucortt (in part), 1905, Proc. U. 8. Nat. Mus., vol. 28, p. 304. (Specimens now referred to M. (P.)
williardi were included with the specimens representing M. (P.) major when this description was written.)
Micromitra (Paterina) williardi Watcorr, 1908, Smithsonian Misc. Coll., vol.53, No.3, p. 60, Pl. VII, fic.7. (Described

and discussed as below as a new species. Fig. 7 is copied in this monograph as fig. 30A.)

Ventral valve subconical, with the apex over the posterior third of the subcircular margin
of the valve; false area narrow but clearly defined by a rather sharp angle on the cardinal slopes
that breaks the curvature of the
shell a short distance from the
margin of the pseudodeltidium;
pseudodeltidium broad, con-
vex, with its lower margin
broadly arched so as to leave
a space between it and the gen-
eral plane of the margin of the
shell. Some specimens of the
pseudodeltidium are uniformly
rounded, in others there is a
narrow groove extending from
the apex to the base, and on
some a very narrow faint ridge

E - is indicated.

FiGguRE 30.— Micromitra (Paterina) williardi Walcott. A, A’, A’, Top, side, and back ofa partly Dorsal valve shehtly con-
flattened ventral valve (U. S. Nat. Mus. Cat. No. 51482a). B, Pseudodeltidium with strong 0
lines and ridges of growth (U. S. Nat. Mus. Cat. No. 51482b). C, Pseudodeltidium with Vex, transverse, and shghtly
median furrow (U. S. Nat. Mus. Cat. No. 51482c). D, A small dorsal valve (U.S. Nat. Mus. younded atthe cardinal maroin.
Cat. No. 51482d). E, Enlargement of the outer surface near the front margin of a ventral 2
valve, X 15(U. S. Nat. Mus. Cat. No. 51482e). Figure 30A represents the type specimen. No traces of a false area or

The specimens represented are from Locality 56c, 1.125 miles (1.8 km.) northeast of Helena, pseudodeltidium have been
Shelby County, Alabama. Figure 30A is copied from Walcott [1908d, Pl. VII, fig. 7). observed.

The cast of the interior of the apex of the ventral valve shows a small apical callosity with
two radiating grooves extending upward toward the front lateral margin of the shell.

Surface marked by very fine, strong, concentric, elevated striz that in a specimen 10 mm.
in diameter show seven elevated striz in a distance of 1 mm.; the elevated strie are crossed
by very fine transverse strie; the elevated striz cross the false area parallel to its base and arch
over the pseudodeltidium.

A ventral valve 10.5 mm. in diameter has a height of 2.5 mm.

Observations.—This species is closely related to Micromitra (Paterina) superba (Pl. Il). It
differs in having a longer pseudodeltidium, more finely elevated strize on the surface, and a more
sharply elevated apex to the ventral valve. It is the Lower Cambrian representative of M. (P.)
superba.

The specific name is given in honor of Mr. T..E. Williard, who collected the type specimen.

Sg AERATED EERE IE Te
Spereseme cane soe eee
Shea ereEaKeRNTee
Pee en en
lanes vichcnisichileninoa ene)

j

FORMATION AND LOCALITY.—Lower Cambrian: (17b) Rome (‘‘Montevallo”) formation, 4 miles (6.4 km.) south
of Helena; and (56c) Rome (‘‘ Montevallo”) formation, 1.125 miles (1.8 km.) northeast of Helena; both in Shelby County,
Alabama.

ee

=<. ©

a ey

PATERINIDA. 309

IPHIDELLA Walcott,¢ subgenus of MICROMITRA.
[Tphidea.]

Kutorgina Watcorr (in part) [not Brxzrnes], 1886, Bull. U.S. Geol. Survey No. 30, pp. 101-102. (Genus Kutorgina
described, but description also includes reference to specimens now referred to Micromitra, Micromitra (Paterina),
and Micromitra (Iphidella).)

Kutorgina Hat and Ciarkz (in part) [not Brnurnes], 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, pp. 90-94.
(Copies Walcott’s description, 1886b, pp. 101-102, and discusses genus, but description and discussion also include
reference to specimens now referred to Micromitra, Micromitra (Paterina), Micromitra (Iphidella), Protorthis, and
Billingsella.)

Tphidea Billings, Watcorr (in part), 1897, Proc. U. S. Nat. Mus., vol. 19, pp. 707-711. (Discussed. The genus as dis-
cussed includes species now referred to Micromitra, Micromitra (Paterina), and Micromitra (Iphidella).)

TIphidella Waxcorr (in part), 1905, Proc. U. S. Nat. Mus., vol. 28, p. 304. (Merely proposed to replace Iphidea, but
includes reference to specimens belonging with Micromitra, Micromitra (Paterina), and Micromitra (Iphidelia).)

Tphidea Billings, Grawav and Surver (in part), 1907, North American Index Fossils, vol. 1, p. 201. (Described
and includes species referred to each of the subgenera Paterina and [phidella.)

Micromitra (Iphidella) Waxcorr, 1908, Smithsonian Misc. Coll., vol. 53, No. 4, Pl. XI, and pp. 142 and 143. (Classifica-
tion of subgenus.)

Iphidella was proposed to replace Iphidea, no species being given as the type. Micromitra
Meek [1873, p. 479] has priority as the generic name, but as [phidella was intended to include
the ornamental crenulated as well as plain type of surface, those species having the former type
are now grouped under /phidella as a subgenus of Micromitra.

Type—Trematis pannulus White.

The species included in this subgenus and the description of their ornamented surfaces are
given under the description of Micromitra (p. 336).

Micromirra (IPHIDELLA) LouIsE Walcott.

Text figures 31A-B.

Micromitra (Iphidella) louise Watcorr, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, pp. 56-57, Pl. VII, figs. 4and 4a.
(Discussed as below as a newspecies. Figs.4 and 4a are copied in this monograph as figs. 831A and 31B, respec-
tively.)

In form this species is not unlike Micromitra pealei (Pl. III, figs. 3, 3a—-e) and the more
elongate form of Micromitra (Iphidella) pannula maladensis (Pl. IV, figs. 2, 2a-g). It differs
from both forms mentioned in its surface characters. In the
latter respect it is more like M. (J.) nyssa (Pl. III, figs. 9, 9a),
but the form of MW. (J.) louise is more elongate and the apex
of the ventral valve is nearer to the posterior margin; the shell
also appears to have been thicker. The surface characters are
exceedingly minute. Underaglassmagnifying twenty diameters |
the surface looks much like that of the anterior half of Plate A
IV, figure 1s. The largest ventral valve in the collection has a Ficure 31.— Micromitra (Iphidella) louise Wal-
length of 7.5 mm. and a width of 7 mm.; elevation, 1 mm. ia ie ara Ra Se

Micromitra (Iphidella) lowise is the oldest known brachiopod Cat. No. 51401a.)_B, Side of laterally com-
from the Cambrian of the Canadian Rocky Mountaims. In the eS Uy Gea Aap aaa
Lakes Louise and Agnes section it is 3,150 feet (960.1 m.) ‘The specimens represented are from the
below the Middle Cambrian, and 2,760 feet -(841.2 m.) below Lower Cambrian siliceous Lake Louise shale,

: 2 : 5 4 at Locality 35d, on the north side of Lake
the horizon which is correlated on the basis of the associated Louise, Alberta, Canada. The figures are

faunas with that at which Jf (/.) nyssa occurs in Montana. ©oPied from Walcott [1908d, Pl. VIT, figs. 4

It occurs in a fine, hard, dark-gray, siliceous shale in Begs

association with Hyolithes, Cruziana, and a fragment indicating the free cheek of a trilobite.

a The synonymy for this subgenus does not give a complete record of the various genera under which the species now included in [phidella were
formerly placed; it includes only those references in which the subgenus is discussed or described. For the sake of completing the record the
remaining mere generic references are here listed:

Trematis White [1874, p. 6]. Iphidea Schuchert [1897, p. 234].
Iphidea Linnarsson [1876, p. 25). Iphidea Matthew [1902b, p. 110].
Trematis White [1877, p. 36]. Iphidea Gronwall [1902, p. 40).

Kutorgina Walcott [1887, p. 190; 1891a, p. 609]. Kutorgina Pack [1906, p. 296).

360 CAMBRIAN BRACHIOPODA.

This form owes its specific name to its occurrence on the shores of Lake Louise.

FoRMATION AND LOCALITY.—Lower Cambrian: (35d) About 3,150 feet (960.1 m.) below the Middle Cambrian in
the siliceous Lake Louise shale [Walcott, 190Sf, p. 216] in cliff on the north side of Lake Louise, at its upper end,
southeast of Laggan on the Canadian Pacific Railway, Alberta, Canada.

Micromitra (IpHIDELLA) Nyssa Walcott.
i]
"Plate III, figures 9, 9a.

Micromitra (Iphidella) nyssa Waxcorr, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, p. 57, Pl. VII, fig. 5. (Described
and discussed as below as a new species. Fig. 5 is copied in this monograph, Pl. III, fig. 9.)

Ventral valve subcircular in outline, with the posterior margin almost transverse; form
depressed, conical, with a minute beak incurving over the pseudodeltidtum. The cardial slope
is compressed in all the specimens, but it indicates that there was an imperfectly defined
narrow area. Pseudodeltidium, as far as can be determined, broad and short, with its lower
margin broadly arched. Dorsal valve slightly convex, beak marginal. No traces of a false
area or pseudodeltidium have been observed.

Surface marked by concentric strie and lines of growth that are crossed obliquely by two
sets of fine elevated lines. The crossing of the latter lines forms minute, shallow, rhomboidal
pits, which give to the surface the appearance of a fine network. On the ventral valve the
strie cross the pseudodeltidium. Shell substance corneous.

Observations.—This is one of the largest shells of this genus. The ventral valve has a length
of 11 mm., width 13 mm. In form it resembles Micromitra (Paterina) labradorica (Billings)
and in surface characters IM. (I[phidella). ornatella (Linnarsson) and some varieties of M. (J.)
pannula (White).

FoRMATION AND LOCALITY.—Middle Cambrian: (4q) About 315 feet (96 m.) above the unconformable base of the
Cambrian and 190 feet (57.9 m.) above the top of the quartzitic sandstones, in a shale which corresponds in strati-
graphic position to the upper part of shale No. 6 [see Walcott, 1908f, p. 202], on the ridge between Gordon and

Youngs creeks, about halfway between Gordon Mountain and Cardinal Peak, Ovando quadrangle(U.S. Geol. Survey),
Powell County, Montana.

MicromitrRA (IPHIDELLA) ORNATELLA (Linnarsson).

‘Pilate III, figures 6, 6a-d.

Iphidea ornatella LinNarsson, 1876, Bihang till K. svensk. Vet.-Akad. Handl., Bd. 3, No. 12, pp. 25-26, Pl. III, figs.
42a-e, 48a-c. (Described and discussed in English as a new species; see below for copy.)

Iphidea ornatella Linnarsson, Hau and CuarKe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, pp. 97-98.
(Mentioned in discussion of genus [phidea.)

Tphidea ornatella Linnarsson, GRONWALL, 1902, Danmarks Geol. Unders¢gelse, Reekke 2, No. 13, p. 40. (Mentioned
in Swedish.)

The original description by Linnarsson follows:

Shell small, transversely oval; sides and front rounded; hinge line straight, or nearly so, shorter than the width
of the shell; cardinal angles rounded. Surface marked with retiform eminences, including small excavations. The
eminences often swell out and become higher at the crossing points, thereby giving to the surface a somewhat granu-

lated appearance (as in fig. 43). In some specimens there are also more or less distinct radiating ridges, especially ~

near the median line of the shell. The shell substance is apparently corneous, but I have not been able to discern
more than one layer.

The color in the specimens from Bornholm is black, in those from Westrogothia more brown. Ventral valve
convex, subconical. Beak erect and pointed, pierced by a minute round foramen. The posterior, visible only in
one specimen, is truncated, so as to form a false area, which has in the middle a triangular fissure, arched over, in
the upper part only, by a convex pseudodeltidium. Dorsal valve less convex, somewhat flattened along the middle;
greatest height at the beak, which is not, however, so prominent as in the opposite valve. Hinge area not visible in
any of the specimens. Interior of both valvesunknown. Two specimens measured: Length 3 mm., breadth 4mm.;
and length 2 mm., breadth 3 mm.

Linnarsson [1876, p. 26] speaks of the presence of a minute foramen, but after the study
of several finely ee ventral valves from the Paradoxides zone of Andrarum, Sweden,
I am led to believe that what he considered to be an apical foramen is the minute longitudinal

— fa. Te

PATERINIDA. a6 1

furrow just in front of the beak, which is shown on the specimens before me and on other
‘species as mentioned in the discussion of the genus Micromitra (p. 335). At first sight it is
very difficult to determine whether there is an apical foramen or not, but with a strong light
and a high power the furrow in JZ. (/.) ornatella is seen to be smooth at the bottom and to
show no trace of an opening down through the shell.

The surface ornamentation is of the same type as that of J (/.) pannula (White). It
differs in details, but the range of variation in the surface of Mf. UI.) pannula (White) is greater
than the differences between its surface and that of Jf (/.) ornatella.

The most marked distinction between the two species is in the form of the false area and
pseudodeltidium of the ventral valve; the dorsal valve of JZ (.) pannula also appears to be
more elevated. These differences, however, might disappear if we had a large number of
specimens of J. (/.) ornatella for comparison. With the material we now have they appear
to be of specific value.

One specimen from Andrarum shows a narrow area on each side of the wide, low, triangular
opening, the pseudodeltidium being broken away. Shell substance corneous.

FORMATION AND LOCALITY.—Middle Cambrian: (8w) Limestones of the Paradoxides forchhammeri zone, at An-
drarum, 20 miles (32.2 km.) northwest of Simrishamn, Province of Christianstad; (320f) limestone at Andrarum, 20 miles
(32.2 km.) northwest of Simrishamn, Province of Christianstad; (820n) limestones of the Paradoxides forchhammeri zone at
Lovened, Djupadal, 19 miles (30.6 km.) south-southeast of Skara, Province of Skaraborg; and (320y) limestones of the Para-
doxides forchhammert zone at Gudhem, 12.5 miles (20.1 km.) south-southeast of Skara, Province of Skaraborg; all in
Sweden.

(324c) Shales of Etage 1d [Brégger] at Krekling, in Sandsvar, N orway.

(16h) Limestones of the Paradoxides forchhammeri zone at Borregaard, Bornholm Island, Denmark.

(6g) Limestone near the base of the Middle Cambrian, the lowest horizon carrying Paradowides, northwest side of
Chapple Arm Harbor, about 1 mile (1.6 km.) from its head, Trinity Bay, Newfoundland.

Micromitra ([PHIDELLA) PANNULA (White).
ye Text figure 32, page 362; Plate IV, figures 1, la-t, 3, 3a.

Trematis pannulus Waite, 1874, U.S. Geog. Surveys W. 100th Mer., Prelim. Rept., p.6. (Described asa new species.)

_ Trematis pannulus Waite, 1877, idem, Final Rept., vol. 4, pt. 1, pp. 36-37, Pl. I, figs. 4a and 4b. (Described and

discussed. The specimen represented by figs. 4a and 4b is redrawn in this monograph, PI. IV, fig. 1g.)

Kutorgina pannula (White), WAucorr, 1886, Bull. U.S. Geol. Survey No. 30, p. 105, Pl. VII, figs. 3, 3a; Pl. VIII, figs.
2, 2a-c. (Copies the description and discussion given by White, 1877, pp. 36-37. Pl. VII, figs. 3 and 3a, are
drawn from the specimen figured by White, 1877, Pl. I, figs. 4aand 4b. The three specimens represented by
figs. 3 and 3a, 2 and 2a, and 2b and 2c are redrawn in this monograph, PI. IV, figs. lg, 1j, and 1k and Ip,
respectively.)

Kutorgina pannula (White), Waucorr, 1887, Am. Jour. Sci., 3d ser., vol. 34, p. 190, Pl. I, figs. 14, 14a—-b. (Character-
ized from a new locality. The two specimens represented by figs. 14 and 14a and fig. 14b are redrawn in
this monograph, Pl. IV, figs. 1m and 1q and figs. 1k and 1p, respectively.)

Kutorgina pannula (White), Waxcort, 1891, Tenth Ann. Rept. U. 8. Geol. Survey, p. 609, Pl. LXIX, figs. 5, 5a—f.
(Mentioned. Figs. 5, 5a, and 5b are copied from Walcott, 1886b, Pl. VIII, figs. 2a, 2, and 2b; figs. 5c, 5e, and 5f
from Walcott, 1887, Pl. I, figs. 14, 14b, and 14a; and fig. 5d from Walcott, 1886b, Pl. VII, fig.3. The six specimens
represented by figs. 5 and 5a and 5b-f are redrawn in this monograph, PI. IV, figs. 1j, 1k, 1m, 1g, 1p, and 1q,
respectively.)

Iphidea pannulus (White), ScHucHERT, 1897, Bull. U. S. Geol. Survey No. 87, p. 234. (Merely changes generic ref-
erence.)

Iphidea pannula (White), MatrHEw, 1902, Trans. Roy. Soc. Canada for 1902, 2d ser., vol. 8, sec. 4, No.3, p.110. (Char-
acterized from a new locality.)

Iphidella pannula (White), WAxcort, 1905, Proc. U.S. Nat. Mus., vol. 28, p. 307. (Merely changes generic reference.)

Kutorgina pannula (White), Pack, 1906, Jour. Geol., vol. 14, No. 4, p. 296, Pl. II, figs. 1, la~c. (Discussed. Figs.
1b and lc are outline drawings after Walcott’s figures, 1886b, Pl. VIII, figs. 2a and 2b; fig. 1a is an outline draw-
ing after Walcott’s figure, 189la, Pl. LXIX, fig. 5d.)

Iphidea pannulus (White), GRABAv and Sumer, 1907, North American Index Fossils, vol. 1, p. 201. (Described.)

Micromitra (Iphidella) pannula (White), Watcorr, 1908, Canadian Alpine Journal, vol. 1, No. 2, p. 244, Pl. I, figs.
1,la-c. (Notextreference. Figs. 1, la-c are copied in this monograph, Pl. IV, figs. Ir, le, 1d, and 1q, respec-
tively.)

Ventral valve conical; beak slightly incurving over the pseudodeltidium. Cardinal slopes
rounded and flattened so as to form a not very strongly defined false area on each side of the

wide, triangular opening, which is crossed toward the summit by a low, highly rounded pseudo-

362 CAMBRIAN BRACHIOPODA.

deltidium; the latter projects directly outward at right angles to the false area and then curves
abruptly, so as to be almost flat across the center. A narrow, slight median groove extends
from beneath the apex to the posterior margin. Another specimen shows a portion of a pseudo-
deltidium that is somewhat less elevated than the one described. The apex of the valve just
outside of the extreme point of the beak is crossed by a very minute longitudinal depression
that is visible only under a strong magnifier.

Dorsal valve slightly convex, sloping regularly from the front margin to the small beak,
which is slightly incurved at the margin of the valve. False area clearly defined; in a speci-
men 10 mm. in width the area has a width of a little over 1 mm. at the side, narrowing to a
point at the apex. It is broken midway by a wide triangular opening, which is filled in by a
depressed pseudodeltidium. The sides of the deltidtum turn in at arly a right angle for a
short distance to the general plane of the pseudodeltidium, which extends across from side to
side. Posterior margin slightly arched, and its general surface broken midway by a narrow,
distinct groove, which extends from beneath the beak back to the posterior margin. (See Pl.
IV, fig. 1f.) Striz of growth extend across

FIGURE 32.— Micromitra (Iphidella) pannula (White). Ventral valve,
showing setze, from Locality 35k, Middle Cambrian, Burgess shale
member of the Stephen formation, near Field, British Columbia.
This specimen is unique in being the first Cambrian brachiopod in
which the setze have been observed. The preservation of so frail a
portion of the anatomy of the brachiopod isno more remarkable,
however, than the presence in the same shales of annelids showing
the fringe of setze around the mouth; of crustaceans of many kinds
showing the branchize and appendages; of-trilobites with antenne,
branchiz, legs, etc.; of holothurians showing the podia and the
dental plates; of medusee, sponges, etc.—a fauna which is now being
described and figured in volume 57 of the Smithsonian Miscel-
laneous Collections.

only in the vicinity of the cardinal slopes.
in Plate IV, figure 1m.

the false areas and pseudodeltidia im both
valves; shell substance corneous.

The surface ornamentation of this species
is as highly ornamental as that of any Cambrian
brachiopod. It appears to be formed of a
very fine network of oblique raised lines, which
divide it up into minute diamond-shaped pore-
like pits, a surface which resembles, under a
strong lens, the texture of finely woven cloth.
A closer examination, however, of some of the
larger shells shows, on the outer margin, cren-
ulated concentric lines, and a little farther back
on the shell more deeply crenulated lines; still
farther back the points of the crenulations
unite so as to form a solid network that gives
the appearance of oblique lines crossing at
nearly right angles (Pl. IV, fig. 1s).

The surface marking is so strongly char-
acteristic that the presence of the species has
been detected a number of times by finding
very small fragments of the shell. It not in-
frequently happens that in old shells the sur-
face characters have been almost entirely worn
away, traces of the ornamentation remaining

The wearing of the surface near the umbo is shown °

In some specimens from Montana (Pl. IV, fe. 1s) the surface is most beautifully pre-

served, and at first glance there appears to be a epecific difference between it and the specimens ~

from Mount Stephen, central Nevada, and the Colorado Canyon. This may be seen by com-
paring figures Ir and 1s (Pl. IV). There are, however, intermediate forms that possess more
or less of the characteristics shown by the two figures. In some specimens there are fine,
radiating undulations extending from the apex to the margin that give to the shell an appear-
ance much like that of the young of I. sculptilis (Meek) and M. (Paterina) stissingensis (Dwight).
These are finely shown by Plate IV, figure In. The surface ornamentation is much like that
of M. (Iphidella) ornatella (Linnarsson) of Sweden. It differs but slightly in the form of the
depression formed by the union of the crenulated striz.

This species has a wide geographic distribution, and it also occurs both in the Lower Cam-
brian in the Olenellus fauna, and in the Middle Cambrian in the Olenoides fauna. Its range in

— a TS

arsed dade id

PATERINID. 363

the West is from Nevada to Montana, and im the Appalachian region from eastern New York
to Alabama. At first, on account of its highly ornamented surface, I was led to think that it
might belong to a distinct genus from Micromitra, but comparisons with MM. sculptilis (Meek)
and the simple ornamentation of IM (Paterine’ bella (Billings) show transitions in the orna-
mentation between the otherwise distinct forms.

Varieties of Micromitra (Iphidella) pannula.—tIn collections from the Middle Cambrian
limestones of northern Utah and southern Idaho, material has been selected for illustration
which represents varieties of form and surface markings of Micromitra (I[phidella) pannula
(White) that might be given specific names were it not for the intermediate phases which occur
at the same locality with the varieties. The specimens from near Malade, Idaho (PI. IV, figs.
2, 2a-2), and many not illustrated, show a wide variation in outlme and surface. Another
series from near Ophir, Utah (Pl. IV, figs. 4, 4a-f), illustrate the entire evolution of the
“nannula” type of surface, from the concentric strive to the fine network of oblique, raised
lines dividing the surface into minute, diamond-shaped depressions. In some of the examples
from Malade the ridges are so sharp and clear that the surface has a honeycomb-like appearance
(PL. IV, fig. 2g).

The surface of M. (1.) pannula (White) is composed of porelike pits formed by obliquely
crossing, elevated lines (Pl. IV, figs. In—1s), and for convenience of reference the forms showing
variations from thismay be separated into the varieties maladensis and ophirensis (pp. 364-365).

FORMATION AND LOCALITY.—Upper Cambrian: (96) Limestones near the ford on the Cedartown road, 1.5 miles
(2.4 km.) south of Rome, Floyd County, Georgia.
Middle Cambrian: (14s) About 2,300 feet (701 m.) above the Lower Cambrian and 2,700 feet (823 m.) below the

Upper Cambrian, in the Ogygopsis zone of the Stephen formation [Walcott, 1908f, p. 210], at the “‘fossil bed,’’ on the
northwest slope of Mount Stephen, above Field on the Canadian Pacific TRsfllszine: (57j) about 2,000 feet (609.6 m.)

‘above the Lower Cambrian in the limestones forming 2 of the Stephen formation [Walcott, 1908c, p. 237 (6)], just east

of the “fossil bed” on the northwest slope of Mount Stephen, above Field on the Canadian Pacific Railway; (58))
about 1,900 feet (579 m.) above the Lower Cambrian near the base of the limestone forming 2 of the Stephen formation

')[Waleott, 1908c, p. 238 (7)]; on the east side of Mount Stephen about 3,000 feet (914 m.) above the Canadian Pacific

Railway track, 3 miles (4.8 km.) east of Field; and (85k) Burgess shale member of the Stephen formation on the west
slope of the ridge between Mount Field and Wapta Peak, 1 mile (1.6 km.) northeast of Burgess Pass, above Field;
all in British Columbia. :

(57g) About 1,700 feet (518 m.) above the Lower Cambrian and 3,250 feet (991 m.) below the Upper Cambrian in
the siliceous shales forming 2d of the Stephen formation [Walcott, 1908f, p. 211], on Mount Bosworth, north of the
Canadian Pacific Railway between Hector and Stephen, on the Continental Divide between British Columbia and
Alberta, Canada.

(4q and 4q’) 315 and 310 feet (96 and 94.5 m.), respectively, above the unconformable base of the Cambrian and
190 and 185 feet (57.9 and 56.4 m.), respectively, above the top of the quartzitic sandstones in shales and limestones
which correspond in position to the upper part of shale No. 6 of the Dearborn River section [see Walcott, 1908f, p. 202],
on the ridge between Gordon and Youngs creeks, about halfway between Gordon Mountain and Cardinal Peak, Ovando
quadrangle (U.S. Geol. Survey), Powell County; (302t) limestone northeast of Logan, Threeforks quadrangle (U.S. Geol.
Survey), Gallatin County; and (149a) limestone at the forks of Pole Creek, above Cherry Creek basin, Threeforks
quadrangle (U. S. Geol. Survey), Madison County; all in Montana.

(55¢ and 163) Spence shale member of the Ute limestone [Walcott, 1908a, p. 8], about 50 feet (15.2 m.) above the
Brigham quartzite and 2,755 feet (839.7 m.) below the Upper Cambrian, in a ravine running up into Danish Flat
from Mill Canyon; and (591) limestones immediately underlying the Spence shale member of the Ute limestone [Walcott,
1908a, p. 8], in a saddle north of the creek which flows into Mill Canyon from the west; both about 5 miles (8 km.)
west-southwest of Liberty and 15 miles (24.2 km.) west of Montpelier, Bear Lake County, Idaho.

(5b and 54s) Dark blue-gray Langston limestone [Walcott, 1908f, p. 198] just above the Cambrian quartzitic
sandstones, north side of Twomile Canyon, near its mouth, 2 miles (3.2 km.) southeast of Malade, Oneida County,
Idaho.

(31v) 650 feet (198 m.) above the Lower Cambrian and 3,750 feet (1,143 m.) below the Upper Cambrian, in shales
at the top of the limestone forming 1a of the Howell formation [Walcott, 1908f, p. 182], northeast side of Dome Canyon,
about 4 miles (6.4 km.) west-southwest of Antelope Springs; and (31s) 490 feet (149.4 m.) above the Lower Cambrian
and 3,925 feet (1,196.3 m.) below the Upper Cambrian, in the pinkish, argillaceous shale forming 1d of the Howell for-
mation [Walcott, 1908f, p. 182], south side of Dome Canyon, about 1 mile (1.6 km.) below the divide and 3 miles
(4.8 km.) west-southwest of Antelope Springs; both in the House Range [Walcott, 1908f, Pl. XIII], Millard County, Utah.

(14t) Limestone lying on the slope between the Cambrian quartzite and the massive blue limestone 100 feet
(30.5 m.) above, Mount Nebo Canyon, 3 miles (4.8 km.) southeast of Mona, Juab County; (55u) limestones about 200

a This species also occurs in Locality 55e.

364 CAMBRIAN BRACHIOPODA.

feet (61 m.) above the Lower Cambrian [see Walcott, 1908f, p. 171], 0.25 mile (0.4 km.) below the Maxfield mine, in Big -

Cottonwood Canyon, on the west front of the Wasatch Mountains southeast of Salt Lake City, Salt Lake County; (30a)
shale on the north side of Big Cottonwood Canyon, 1 mile (1.6 km.) below Argenta, in the Wasatch Mountains southeast
of Salt Lake City, Salt Lake County; and (541) about 500 feet (152.4 m.) above the Brigham quartzite and 3,700 feet
(1,127.8 m.) below the Upper Cambrian in the Spence shale member of the Ute limestone [Walcott, 1908f, p. 197], in
Blacksmith Fork Canyon, about 10 miles (16.1 km.) east of Hyrum, Cache County; all in Utah.

(31) Shales at the Chisholm mine; and (3383 [Pack, 1906, p. 296]) shales at the Abe Lincoln mine; both on the
southwest slope of the Ely Mountains, 3 miles (4.8 km.) northwest of Pioche, Lincoln County, Nevada.

' (78a) ‘‘Tonto” sandstone in Chuar Valley; and (74) sandstone about 300 feet (91.4 m.) above the base-of the
Tonto group, at the head of Nunkoweap Valley; both in the Grand Canyon of the Colorado, Arizona.

(14) Limestones overlying the sandstones of the Rome formation, near the wagon road and in a quarry near the
railroad track, 7 miles (11.2 km.) southwest of Rome, Floyd County, Georgia. 2

(101) Rogersville shale, just above the road in the hill west of the schoolhouse, 3.5 miles (5.6 km.) southwest of
Rogersville on the road to Melinda Ferry [Keith, 1896a, areal geology sheet], Hawkins County, Tennessee.

Lower Cambrian: (57r and 58s) About 150 feet (46 m.) below the Middle Cambrian near the base of the limestones
forming 3 of the Mount Whyte formation [Walcott, 1908c, p. 241 (10)]; and (85f)¢ about 300 feet (91 m.) below the
Middle Cambrian in the limestone forming 6 of the Mount Whyte formation [Walcott, 1908c, p. 242 (11)]; both just
above the tunnel on the north shoulder of Mount Stephen, about 3 miles (4.8 km.) east of Field, British Columbia,
Canada.

(41) Limestone in the Pioche shale [Walcott, 1908a, p. 11], on a ridge 2.5 miles (4 km.) northwest of the town of
Cherry Creek, White Pine County; (30) limestone 8 miles (12.8 km.) north of Bennetts Spring, on the west slope of
the Highland Range, Lincoln County; and (81a) limestone interbedded in the Pioche shale [ Walcott, 1908a, p. 11], just
above the quartzite on the east side of the anticline, near Pioche, Lincoln County, all in Nevada.

(34) Limestone on roadside a little west of the bridge over Poultney River at Low Hampton, about 5 miles
(8 km.) east-northeast of Whitehall, Whitehall quadrangle (U. S. Geol. Survey), Washington County; (38a) lime-
stone 2 miles (3.2 km.) south of North Granville, on the road which turns south from the road running between that
village and Truthville, 4 miles (6.4 km.) west-northwest of Granville, Fort Ann quadrangle (U. S. Geol. Survey),
Washington County; and (44b) limestone near North Chatham in the northern part of the Kinderhook quadrangle
(U. 8. Geol. Survey), Columbia County; all in New York.

(4v) About 200 feet (61 m.) above the unconformable base of the Cambrian and 75 feet (22.9 m.) above the top
of the quartzitic sandstones in a shale which corresponds in stratigraphic position to shale No. 6 of the Dearborn
River section [Walcott, 1908f, p. 202], Gordon Creek, 6 miles (9.6 km.) from South Fork of Flathead River,
Ovando quadrangle (U. 8. Geol. Survey), Powell County, Montana.

Specimens that are somewhat doubtfully referred to this species occur at the following
localities:

Middle Cambrian: (55c) Spence shale member of the Ute limestone [Walcott, 1908a, p. 8], about 50 feet (15.2 m.)
above the Brigham quartzite, and 2,755 feet (839.7 m.) below the Upper Cambrian, in a ravine running up into Danish
Flat from Mill Canyon, about 6 miles (9.6 km.) west-southwest of Liberty and 15 miles (24.2 km.) west of Montpelier,
Bear Lake County, Idaho.

(54q) A drift block supposed to have come from the horizon of Locality 32x, a horizon correlated with the shales
forming 2d of the Bloomington formation in Blacksmith Fork Canyon [Walcott, 1908f, p. 195], in Wasatch Canyon,
east of Lakeview ranch, about 5 miles (8 km.) north of Brigham, Boxelder County, Utah.

(18k) Shales of Matthew’s [1903, p. 15] Coldbrook, above the great falls in Dugald Brook, Indian River, eastern

Cape Breton, Nova Scotia.

Micromitra (IPHIDELLA) PANNULA MALADENSIS (Walcott).
Plate IV, figures 2, 2a-g.
Tphidella pannula maladensis Waucorr, 1905, Proc. U. 8. Nat. Mus., voi. 28, p. 306. (Characterized as a new variety.)

Surface covered with elevated, sharp, distinct ridges that give it an irregular, honeycomb-
like appearance.
This form owes its varietal name to its occurrence near Malade, Idaho.

FORMATION AND LOCALITY.—Middle Cambrian: (5b) Dark blue-gray Langston limestone [ Walcott, 1908b, p. 198] just
above the Cambrian quartzitic sandstones, on the north side of Twomile Canyon, near its mouth, 2 miles (3.2 km.) southeast
of Malade, Oneida County, Idaho. 5

(6g) Limestone near the base of the Middle Cambrian, the lowest horizon carrying Paradowides, northwest side of
Chapple Arm Harbor about a mile (1.6 km.) from its head, Trinity Bay, Newfoundland.

a This species is somewhat doubtfully identified from this locality.

a

ce

re

ay. pele NOEL ENS!

PATERINID. - Bho)

_ Micromirra (IPHIDELLA) PANNULA OPHIRENSIS (Walcott).

Plate IV, figures 4, 4a-f.
Iphidella pannula ophirensis Waucorr, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 306. (Characterized as a new variety.)

Surface formed by raised, concentric lines and ridges that inosculate and become more and
more irregular until the typical surface of Micromatra (Iphidella) pannula is developed.
This form owes its varietal name to its occurrence at Ophir, Utah.

ForRMATION AND LOCALITY.—Middle Cambrian: (3e) Thin-bedded limestones less than 400 feet (121.9 m.) above the
quartzitic sandstones of the Cambrian, near Ophir, Oquirrh Range, Tooele County, Utah.

Shells that I can not separate from this variety occur at the following localities:

Middle Cambrian: (3x) About 2,200 feet (670.6 m.) above the Lower Cambrian and 2,200 feet (670.6 m.) below the
Upper Cambrian, in the limestone forming 1d of the Marjum limestone [Walcott, 1908f, p. 180], 2.5 miles (4km.) east of
Antelope Springs, in ridge east of Wheeler Amphitheater; and (110) about 2,750 feet (838.2 m.) above the Lower Cam-
brian and 1,650 feet (502.9 m.) below the Upper Cambrian, in limestone at the base of la of the Marjum lime-
stone [Walcott, 1908f, p. 179], about 4 miles (6.4 km.) southeast of Antelope Springs, in the spur at the junction of the
Deseret and Swasey Spring roads; both in the House Range [Walcott, 1908f, Pl. XIII], Millard County, Utah.

(54s) Dark blue-gray Langston limestone [Walcott, 1908, p. 198], just above the Cambrian quartzitic sandstones,
on the north side of Twomile Canyon, near its mouth, 2 miles (3.2 km.) southeast of Malade, Oneida County, Idaho.

(14s) About 2,300 feet (701 m.) above the Lower Cambrian and 2,700 feet (823 m.) below the Upper Cambrian, in
the Ogygopsis zone of the Stephen formation [Walcott, 1908f, p. 210], northwest slope of Mount Stephen, above Field
on the Canadian Pacific Railway, British Columbia, Canada.

Fragments of shells that are not to be separated by their surface characters from JMJicro-
mitra (Iphidella) pannula ophirensis occur in China. The fragments also indicate that the
shells were about the same size and form.

Middle Cambrian: (C5) Lower limestone member of the Kiulung group [Blackwelder, 1907a, pp. 37 and 39], 3.2
miles (5.1 km.) southwest of Yenchuang, Sintai district, Shantung, China.

~ Genus VOLBORTHIA von Moller.

Volborthia von MoéuuEr, 1874, Neues Jahrb. fiir Mineralogie, pp. 449-452. (Described and discussed in German as a
new genus; see below for free translation of description on pp. 449-451.)

Acrotreta ( Volborthia) (von Moller), OrHLERT, 1887, Manuel de conchyliologie, by Fischer, p. 1266. (Described in
French as a subgenus, with figures of ‘‘Acrotreta ( Volborthia) recurva (Kutorga).’’)

Volborthia von Méller, Hatt and CrarKe, 1892, Eleventh Ann. Rept. State Geologist New York for 1891, p. 249.
(Described.)

Volborthia von Moller, Harn and Ciarke, 1892, Forty-fifth Ann. Rept. New York State Mus. for 1891, p. 565. (Copy
of preceding reference.)

Volborthia von Méller, Haun and Crarxe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, pp. 95-96. (Original
description, von Méller, 1874, pp. 449-451, translated essentially as below and genus discussed.)

Volborthia von Méller, Waucorr, 1908, Smithsonian Misc. Coll., vol. 53, No. 4, Pl. XI, and pp. 142 and 143. (Classifi-
cation of genus.)

The description in substance by von Moller [1874, pp. 449-451] is as follows:

The shells remind one in their form of a broad horn whose opening is closed through a very convex cover (the
dorsal valve). Seen from above, the outline of the figured shell, in consequence of the rounded edges and the likewise
rounded front edge, is transversely oval. Only the posterior edge, whose length is about one-half of the breadth of the
shell, appears straight.

The ventral valve is very high, conical, and has a strong, recurved, prominent beak without any perforation.
Between the beak and the hinge line (posterior edge} is a distinctly marked and high three-cornered area, whose length
is divided by a narrow ridge extending from the beak to the middle of the straight hinge line.

The dorsal valve is convex, nevertheless decidedly lower than the ventral, and it has just such a beak as the other.
Although this beak lies in the same vertical line with that of the opposite valve, it nevertheless touches the hinge line
of the shell, without any area lying between.

The surface of both valves is smooth and covered only with very fine concentric growth strie, which extend
without interruption also over the area of the ventral valve. On the latter they appear much coarser and not so
regular, especially on the ridge where these strize are rather strongly bent downward toward the beak of the ventral
valve. =

Neither the ventral nor the dorsal valves appear to have inward projections; at least the casts (molds) show not the
slightest traces thereof. Likewise the muscle scars are not known, and on the casts are usually found only a small

a Prior to the definition of Volborthia by von Moller [1874, p. 449] the species now referred to this genus was placed under Acrotreta Kutorga
[1848, p. 277].

366 CAMBRIAN BRACHIOPODA.

number of widely separated radial lines. As regards the substance of the shell, it must be remarked that it is exactly
the same as in the genus Siphonotreta, i. e., calcareous-horny, and of a brown color. Under the microscope, enlarged
six to eight times, the valves show a fine but distinct puncturing, invisible to the unaided eye.

As regards the dimensions of the shell, the largest examples have a length of 14, a breadth of 19, and a thickness of
16 mm., while the height of the ventral valve is 10 mm.

Hall and Clarke [1892c, p. 96] compare this genus with Autorgina on account of the general

form and surface characters, and call attention to the presence of an areal ridge similar to that —

of “Iphidea” = Micromitra. The authors were under the impression that an apical foramen
existed in Micromitra and probably in Volborthia and that the areal ridge was the ‘“‘ecurved”’
foramen scar. I do not find a foramen in Micromitra, and none has iyeen seen in Volborthia.
The areal ridge appears to be the arched pseudodeltidium, both in Micromitra [PI. III, fig. 3b]
and Volborthia [P\. I, fig. 6el.

The previously published illustrations of Volborthia recurva do not show any opening
between the posterior margins of the valves, but that there was an opening for the passage of the
pedicle is shown in figures 334 and 33A’.

The absence of dletmed muscle scars and vascular markings i is a characteristic of this genus.

The generic name was given in honor of Dr. A. von Volborth.

Type.—Acrotreta recurva Kutorga.

l VOLBORTHIA RECURVA (Kutorga).

Text figures 33A—B; Plate I, figures 6, 6a-e.
Acrotreta recurva KutorGA, 1848, Verhandl. Russ.-kais. min. Gesell. St. Petersburg for 1847, No. 12, pp. 277-278, Pl. VII,

figs. 9a and 9d. (Characterized and discussed in German as a new species. The description of Pl. VII gives-

the name of the species as ‘‘ Acrotreta incurva.”’ The only figures accompanying the reference are those men-
tioned, 9a and 9d.)

FIGURE 33.— Volborthia recurva (Kutorga). A, Posterior view of specimen figured by von Moller, 1874, Pl. VII, figs. 1-6.
A’, Enlargement of same to show pedicle opening, light from theright. B, Posterior view of an associated ventral
valve showing crenulation of the striz on the false area.

The specimens represented are from Locality 336g, limestone in the vicinity of Zarskoe Selo, Russia. The
specimens are now in the museum at Reval, but a cast of the type specimen represented in figures 33A—A’ is in the
collections of the U. S. National Museum, Cat. No. 58298.

Volborthia recurva (Kutorga), von M6uumr, 1874, Neues Jahrb. ftir Mineralogie, pp. 449-452, Pl. VII, figs. 1-6. (The
description and discussion of the species is included in that of the genus, which is in German and which is trans-
lated on pp. 355-356. Jigs. 1-6 are copied in this monograph, Pl. I, figs. 6, 6a—e, respectively. The specimen
represented by figs. 6, 6a—e of von Méller’s paper is redrawn in this monograph, figs. 33A—A’.)

Volborthia recurva (Kutorga), Hann and Ciarxke, 1892, Eleventh Ann. Rept. State Geologist New York for 1891, figs.
261 and 262, p. 249. (No text reference. Figs. 261 and 262 are copied from von Méller 1874, Pl. VII, figs. 2
and 6, respectively.)

Volborthia recurva (Kutorga), Haru and CiuarKs, 1892, Forty-fifth Ann. Rept. New York State Mus. for 1891, figs. 261
and 262, p. 565. (Copy of preceding reference.)

Volborthia recurva (Kutorga), Harn and CrarKe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, pp. 95-96,
figs. 52 and 58. (The description of the species is included in that of the genus, which is translated, essentially
as on pp. 300-356 of this suonogHph, from von Méller, 1874; pp. 449-451. Figs. 52 and 53 are copied from
von Méller, 1874, Pl. VII, figs. 2 and 6, respectively.)

The generic description includes the important characters of this, the only known species.

FORMATION AND LOCALITY.—Ordovician: (336g [Kutorga, 1848, p. 278]) Limestone in the vicinity of Zarskoe Selo,
and (337]j [Fr. Schmidt, personal communication, 1908]) zone BIII@ or BIIIP, characterized by Asaphus raniceps, a
little above the zone with Asaphus expansus, at Obuchow (Obookhoy), on Wolchow River; both in the Government
of St. Petersburg, Russia.

PATERINID. 367

Genus HELMERSENIA Pander.

Siphonotreta JEREMEJEW, 1856, Verhandl. Russ.-kais. min. Gesell. St. Petersburg for 1855-6, No. 2, pp. 73 and 80.

(New species S. ladogensis described in German.)

Helmersenia PANDER, 1861, Bull. Acad. imp. sci. St.-Pétersbourg, vol. 3, columns 48-49. (Jeremejew’s species
described and discussed in German.)
Helmersema Pander, Zirret, 1880, Handbuch der Paleontologie, Bd. I, Abth. 1, p. 666. (Described in German.)
Keyserlingia Karinsky, 1887, Bull. Acad. imp. sci. St.-Pétersbourg, vol. 31, p. 476, footnote. (The use of Keyser-
lingia in this footnote is clearly a typographical error, Helmersenia being intended. The genus is discussed
in German.) “
Helmersenia Pander, OEHLERT, 1887, Manuel de conchyliologie, by Fischer, p. 1264. (Described in French, see p. 369.)
Helmersena Pander, Haut and CiarKe, 1892, Eleventh Ann. Rept. State Geologist New York for 1891, p. 254.
: (Described.)
Helmersenia Pander, Hatt and CiarKe, 1892, Forty-fifth Ann. Rept. New York State Mus. for 1891, p.570. (Copy
of preceding reference.)
Helmersenia Pander, Hatt and CrarKe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, p. 119. (Copies Hall
and Clarke, 1892a, p. 254, and discusses genus.)
Helmersenia Pander, Waxcort, 1908, Smithsonian Misc. Coll., vol. 53, No. 4, Pl. XI, and pp. 142 and 143. (Classi-
n fication of genus.)

General form longitudinally ovate, subcircular to transversely ovate, with the ventral
valve broadly subacuminate and dorsal valve broadly rounded except at the minute beak;
ventral valve moderately convex, rising on the umbo and sloping most rapidly down to the
minute, nearly marginal beak; dorsal valve gently convex with apex marginal.

The interior of the ventral valve shows a narrow area with a thickened median ridge ex-
tending a short distance forward to the visceral area. The latter has the general form of the
visceral area of Obolus, with the muscle scars in front on each side of the center. One specimen
shows the central and the outside and middle lateral scars; beneath the area, at the base of the
median ridge, the main vascular sinuses arch outward and then forward; between the vascular
sinus and the outer margin of the shell there are indications of the transmedian and anterior
lateral muscle scars. The interior of the dorsal valve shows a slender median ridge extending
well forward into the valve, and the main vascular sinuses well out toward the side of the shell.
None of the specimens show the muscle scars of this valve, and I have not been able to find
more than the broken margin of the area.

Surface marked by concentric strie and a few stronger lines of growth. Scattered irreg-
ularly over the surface on the epidermal layer there are elongate bases of numerous slender
spines that closely resemble the bases of the spmes of Siphonotreta verrucosa (Kichwald). The
inner surface is minutely punctate with a few larger scattered puncte.

The shell varies in size from 2 to 3 mm. in diameter. It rarely exceeds 2 mm.

Type.—Siphonotreta ladogensis Jeremejew.

From Pander’s remarks [1861, p. 48] in describing the genus Helmersenia it is evident that
he considered the shells described by Jeremejew [1856, p. 73] as Siphonotreta ladogensis as belong-
ing to this genus. As pointed out by Karpinsky [1887, p. 476] the form studied by Pander
differs from S. ladogensis in being more circular in outline. I strongly suspect, however, that
if the types of S. ladogensis were compared with the material used by Pander they would be
found to be specifically identical. The figures given by Jeremejew [1856, p. 73] in my opinion
represent young snells of the form subsequently named by Karpinsky.

Through the courtesy of Dr. Fr. Schmidt, of the Geological Survey of Russia, I have had
the opportunity of studying specimens of Helmersenia collected by Karpinsky at Kunitz, in the
Government of Pskow. I also received from Dr. A. Mickwitz some fine specimens collected at

--Koporje, in the Government of St. Petersburg. With the specimens from Kunitz there some-
what rarely occurs Keyserlingia buchi (de Verneuil) and large numbers of Obolus* (Schmidtia)
celatus Volborth. The associated forms at Koporje are Obolus (S.) celatus and fragments of a
larger Obolus.

Pander [1861, p. 48] describes the ventral valve of this species as having at the top of the
beak a circular opening that does not, as in the “‘Siphonotretem,”’ extend into a canal. I have
carefully studied with a strong lens more than one hundred specimens of the ventral valve of

368 CAMBRIAN BRACHIOPODA.

this species, and in only three specimens have I found what might be considered to be a perfora-
tion at the apex of the shell. In one of these it was clearly a circular fracture of the shell, and
in the other two the apex had been pushed in so as to form a small circular depression with sharp
edges. Several interiors of the shell also fail to show any indication of an opening through the
shell; the specimen illustrated by Pander [1861, Pl. II, fig. 2b] and the enlargement (g) are very
much like the specimen with the minute circular opening caused by fracture. There are several
other specimens in which there is a slight depression just in advance of the beak, which indicates
that the shell was very thin and slightly flexible at this pomt. JI would not venture to suggest
that this was an imperfect ventral valve were it not for the fact that I have such an abundant
supply of material which is clearly to be referred to the form described by Pander. I would
further state that it frequently occurs that the apex of the shell is slightly raised above
the surface so as to form a minute node and that when the apex is pushed in the edge of the
depression follows a concentric line of growth.

If we consider that Helmersenia is not a perforate shell, it then falls in with Obolus except
that the area of the ventral valve is unlike that of Obolus and it has a spinose outer surface:
The area, as illustrated by Pander [Pl. LXIII, fig. 7d], is of the Mickuitzia monilifera type
(Pl. VI, fig. 1’). The shells of Helmersenia are delicate and much more like those of Mickwitzia
than Obolus. The outer surface of Mickwitzia is not known to be spinose, but if we compare
the surface shown by figures 1n and 2 (PI. VI) with figures 7, 7a—b (Pl. LXIII) of Helmersenra we
gain an ‘mpression of their great similarity. On account of the character of the area of the
ventral valve, the appearance of the shell, and its surface, Helmersenia is placed within the
Paterinide.

The generic name was given in honor of Grégoire de Helmersen.

HELMERSENIA LADOGENSIS (Jeremejew).

F-

a Plate LXIII, figures 7, 7a-f.

Siphonotreta ladogensis JEREMEJEW, 1856, Verhandl. Russ.-kais. min. Gesell. St. Petersburg for 1855-6, No. 2, pp. 73
and 80, figs. 5a-c, p. 73. (Described in German on p. 80, as a new species.)

Discina buchit ErcHwap (in part) [not (DE VERNEUIL)], 1860, Lethea rossica, ancienne période, vol. 1, sec. 2, p. 914:
(Includes Siphonotreta ladogensis with Discina buchit.)

Helmersenia PANDER, 1861, Bull. Acad. imp. sci. St.-Pétersbourg, vol. 3, columns 48-49, PI. II, figs. 2a-g. (Described
and discussed in German. Figs. 2d and 2f are copied in this monograph, Pl. LXIII, figs. 7d and 7e,
respectively.)

Helmersenia jeremejewi Dawu, 1877, Bull. U. S. Nat. Mus. No. 8, p. 31. (See the text below for discussion of this
reference.)

Keyserlingia panderi Karprinsky, 1887 (April), Bull. Acad. imp. sci. St.-Pétersbourg, vol. 31, p. 476, footnote. (Dis-
cussed in German; see below.) E

Helmersenia jeremejewi Dall, ObaLERT, 1887 (June), Manuel de conchyliologie, by Fischer, p. 1264. (Mentioned in
French as type of genus; see below.)

Helmersenia sp.? Pander, Hatt and CrarKke, 1892, Eleventh Ann. Rept. State Geologist New York for 1891, p. 254,
Pl. IV, figs.6 and 7. (Mentioned in the text, which is a description of the genus. Figs. 6 and 7 are copied from
Pander, 1861, Pl. II, figs. 2d and 2b, respectively.)

Helmersenia sp.? Pander, Hatt and CuarKe, 1892, Nat. Hist: New York, Paleontology, vol. 8, pt. 1, p. 119, Pl. IV,
figs. 4 and 5. (Mentioned. Figs. 4 and 5 are copied from Hall and Clarke, 1892a, Pl. IV, figs. 6 and 7, respec-
tively.)

The specific description of this species has been included in the generic description.
Pander [1861, p. 48] gave no specific name to the form which he described as Helmersema,
but he refers to Siphonotreta ladogensis Jeremejew in such a manner as to indicate that he con-

sidered that species as the type. i
In 1877 Dall published a list of the names applied to the subdivisions of the Brachiopoda,

and [1877, p. 31] designated the type species as Helmersenia jeremejeur, ascribing the species to

Pander and referring to page 47 of Pander’s paper. Pander [1861, p. 48] places the words

' “Siphonotreta Jeremejew” after Helmersenia, refers to the place of publication of Siphonotreta ?

ladogensis Jeremejew, and discusses the generic relations of the specimens before him with

Siphonotreta ladogensis. It is thus evident that Pander did not name the species H. jeremejewt.

> > wlan. Peed eee O0n ser bo ten Se eee

CURTICIID. 069

Dall tells me that he did not see Jeremejew’s paper in which the specific name ladogensis was
proposed.

Ten years later Karpinsky [1887, p. 476], in his report on the Geology of the Government
of Pskow, gives a list of the species occurring in the Ungulite sandstone and places a footnote
after the word Helmersenia, in which he refers to “ Keyserlingia” and suggests that the species
be called “ Keyserlingia panderi.”’ In this footnote he mentions ‘‘ Keyserlingia” three times, but
places after the first a reference to Pander’s description of Helmersenia. It is evident that
Karpinsky intended to specifically identify pandert with Helmersenia and not Keyserlingia.

A few months after the appearance of Karpinsky’s paper Oebhlert, in Fischer’s Manuel de
Conchyliologie, describes the genus Helmersenia [1887, p. 1264] and gives as the type H. jeremejewi
Pander. He gives no reference, but it is likely that he followed Dall.

This form owes its specific name to its occurrence near Ladoga, near St. Petersburg, Russia.

FORMATION AND LOCALITY.—Upper Cambrian: (3360) Ungulite grit, Koporje, Government of St. Petersburg;
(3836p) Ungulite grit, Kunitz, Government of Pskow; and (386q [Jeremejew, 1856, pp. 73 and 80]) Ungulite sandstone,
near Ladoga, Government of St. Petersburg; all in Russia.

Superfamily OBOLACEA Schuchert.
Family CURTICIID Walcott and Schuchert.
Genus CURTICIA Walcott.

Curticia Waxtcort, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 319. (Mentioned as below as a new genus.)
Curticia Watcorr, 1908, Smithsonian Misc. Coll., vol. 53, No. 4, Pl. XI, and pp. 142 and 143. (Classification of genus.)
The description of the type species, Curticia elegantula, includes all that is known of this
genus.
The generic name is given in recognition of the excellent work of Dr. Cooper Curtice, of
Moravia, New York, both as a field collector and laboratory assistant.

CURTICIA ELEGANTULA Walcott.
Plate I, figures 2, 2a-l.

Curticia elegantula Watcorr, 1905, Proc. U. 8. Nat. Mus., vol. 28, pp. 319-320. (Described and discussed as below as
a Dew species.)

Y

General form subcircular, biconvex. Surface of exterior of shell marked by fine, concentric,
slightly undulating striz, and lines and varices of growth. When the thin exterior layer is
exfoliated, the inner layers are ornamented by numerous fine, radiating lines, very much as
in Dicellomus and Obolus, also by more or less imbricating concentric lines. The inner surface
shows radiating and concentric lines without the visceral area. Shell substance corneous and
probably calcareous. The shell is built up of a thin, outer, surface layer and several inner
layers or lamelle, slightly oblique to the outer surface on the umbo and central parts of the
valves. The lamellz are more oblique and numerous toward the front and sides, and thus
thicken the shell over those parts. The average ventral valve has a length of 5 mm.; width,
6 mm.; dorsal valve, 5 mm. by 5 mm.

Ventral valve strongly convex, most elevated at the umbo, and arching over to a minute,
slightly incurved apex; area rudimentary, with a high, triangular, open delthyrium occupying
most of it. A cast of the interior of the valve shows that a narrow, elevated ridge occurs just
in advance of the apex, and a very small visceral area is indicated.

Dorsal valve evenly convex, apex marginal; cardinal area rudimentary, narrow, and
divided by a low, broad, open delthyrium. The interior shows a median ridge and septum,
with small rounded depressions beneath the umbo on each side of the median ridge and a little
in advance of the apex. Ventral muscle scars small and clearly defined. Anterior lateral
sears small and situated in advance of the central scars close to the median ridge and at its
anterior extremity. Main vascular sinuses broad and slightly defined.

Observations.—This shell was labeled by the field collector as Dicellomus politus. In
external form it resembles that species, but the open delthyrium of the ventral valve and the

62667°—vot 51, pr 1—12—24

370 CAMBRIAN BRACHIOPODA.

absence of an area on the dorsal valve distinguish it. It appears to be a form intermediate in
development between Rustella, with its absence of cardinal areas and its very rudimentary
pedicle aperture, and Obolus, with its well-defined cardinal areas with their pedicle grooves. It
occurs in large numbers and its dark smooth shell is a very striking object in the bufi-gray
sandstone. ‘

FoRMATION AND LOCALITY.—Upper Cambrian: (82b) ‘‘St. Croix sandstone” along the railroad track near Taylors
Falls, Chisago County, Minnesota.

Family OBOLID King.
Subfamily OBOLINA Dall.
Genus OBOLUS Eichwald.¢

[éBeddc, 2 coin.]

Obolus E1cHWALp, 1829, Zoologia specialis, vol. 1, p. 274. (Described in Latin as a new genus.)

Unguliten PaNpER, 1830, Beitrage zur Geognosie des russischen Reiches, pp. 55-58. (Described and discussed in
German.)

Ungula Panner, 1830, idem, pp. 57-58. (Proposed as a new genus on p. 57 and described in German.)

Ungulites QuENstEpT, 1837, Archiv fiir Naturgeschichte, von A. F. A. Wiegmann, Jahrg. 3, Bd. 1, pp. 143-145.
(Refers to Pander’s new genus Ungula as “‘ Ungulites” and describes the genus in German.)

Orthis von Bucu (in part), 1841, Archiv ftir Mineralogie, Bd. 15, Hft. 1, p.7. (Merely describes and discusses Obolus
apollinis as ‘‘Orthis ungula,’’ and refers the species to the ‘‘ Unguliten,” the text being in German.)

Unguliten Pander, von Bucu, 1841, idem, p.7. (The description of this group is incorporated with that of the species
“Orthis ungula”’ (Obolus apollinis), the text being in German.)

Obolus Eichwald, pz Vernevt, 1845, Géologie de la Russie d’Europe, by Murchison, de Verneuil, and de Keyserling,
vol. 2, pt. 3, p. 291. (The genus is discussed in French in the third and fourth paragraphs on p. 291, under
Obolus apollinis; see Matthew, 1892, pp. 43-44, for translation.)

Obolus Hichwald, Kurorea, 1848, Verhandl. Russ.-kais. min. Gesell. St. Petersburg for 1847, No. 12, pp. 250-253.
(Discussed in German.)

Aulonotreia Kurorea (in part), 1848, idem, pp. 278-279. (Described in German as a new genus, the species in the
genus belonging with Obolus, Obolus (Acritis), and Obolus (Mickwitzella).

Obolus Eichwald, Morris, 1849, Annals and Mag. Nat. Hist., 2d ser., vol. 4, pp. 319-320. (Discussed.)

Obolus Eichwald, Davipson (in part), 1853, British Fossil Brachiopoda, vol. 1, introduction, No. 3, pp. 135-186.
(Described and discussed. The species referred to the genus belong with Obolus, Obolus (Acritis), and Obolus
(Mickwitzella). Two of the species, Obolus davidsoni and Obolus transversa, are Ordovician forms and are not taken
up in this monograph.)

aThe synonymy for this#genus does not give a complete record of the various genera under which the species now included in Obolws were
formerly placed; it gives only those references in which the genus is discussed or described. To complete the record for the species taken up in
the monograph the following mere generic references are listed:

Obolus von Leuchtenberg [1843, p. 16].

Orbicula Owen [1852, p. 583].

Lingula Billings [1859, p. 431].

Obolus Schmidt [1861, p. 218}.

Lingula Billings [1863, p. 124].

Lingulepis Hall [1863, pp. 129 and 130}.

Lingula Billings [1865a, p. 216].

Obolus? Billings [1865b, p. 362].

Lingulepis Hall [1867, p. 107).

Lingula Barrande [1868a, p. 100).

Obolus? Barrande [1868a, pp. 104 and 105).

Lingula Barrande [1868b, p. 690].

Obolus? Barrande [1868b, p. 693].

Lingulella? Meek [1871, p. 185].

Obolus Billings [1872a, p. 218; 1872c, p. 356).

Obolus Kayser [1876, p. 9].

Oboluws Roemer [1876, Pl. II, figs. 7a-c].

Obolella Hall and Whitfield [1877, p. 205).

Lingulepis Hall and Whitfield [1877, p. 206).

Lingula Barrande [1879b, Pls. CVI: 1v; CX: vi; CXI:
1, and CXT: vij.

Obolus? Barrande [1879b, Pls. XCV: 1v; CXI: v1;
CXIII: v; CXXVI: a; and CLII: nj.

Obolus Noetling [1883, p. 265].

Lingulella Kayser [1883, p. 35].

Lingulepis Walcott [1884b, p. 12].

Obolella Walcott [1884b, p. 14].

Obolus Roemer [1885, p. 23 (270)].

Obolella? Walcott [1886b, p. 111).

Lingulella Walcott [1889¢e, p. 441).

Obolus Gagel [1890, p. 21].

Lingula Bornemann [1891, p. 438].

Obolella Bornemann [1891, pp. 439 and 440).

Lingulella? Hall and Clarke [1892c, p. 61).

Obolelia?? Hall and Clarke [1892c, pp. 69 and 73).

Lingulella Keyes [1894, p. 38].

Lingulella Matthew [1895b, p. 255).

Lingula Sardeson [1896, p. 95].

Schmidtia Mickwitz [1896, p. 19].

Glossina Schuchert [1897, p. 224).

Lingulella? Walcott [1897a, p. 404].

Obolus (Lingulella) Walcott [1898b, pp. 404, 412, 415,
416, 418,and 419; 1899, pp. 443 and 445; 1901, p. 673].

Obolus Walcott [1901, p. 684].

Obolus Matthew [1902c, pp. 94 and 96).

Obolus (Monobolina) Matthew [1902e, p. 98).

Lingulella Matthew [1902c, p. 108).

Obolus (Lingulella) Waleott [1902, p. 605).

Lingulella Matthew [1903, p. 62).

Obolus Matthew [1903, p. 76].

Monobolina Matthew [1903, p. 210].

Obolus Walcott [1905a, pp. 324, 325, 326, 327, and 328).

Obolus (Lingulella) Walcott [1905a, pp. 328, 330, and
331).

Obolus Moberg and Segerberg [1906, p. 65]

Obolus Walcott [1908c, p. 244; 1908d, pp. 61, 62, and
63).

OBOLIDL. 371

Obolus EicHwatp (in part), 1860, Lethzea rossica, ancienne période, vol. 1, sec. 2, pp. 924-925. (Described in French.
The species referred to the genus belong with Obolus, Obolus (lca, and Obolus ( Mickwitzella).)

Obolus Bichwald, Davipson, 1866, British Fossil Brachiopoda, vol. 3, pt. 7, No.1, p.58. (Gives synonymy and refers
genus to Lingulide. )

Not Schmidtia von Vowsortu, 1869, Verhandl. Russ.-kais. min. Gesell. St. Petersburg, 2d ser., pt. 4, pp. 208-209.
(Characterized and discussed as a new genus to include those forms which had been referred to Ungula, but
which were not included in Ungulites Quenstedt, 1837, p.143. Schmadtia celatus is, however, described as the
only representative of the new genus.)

Obolus Eichwald, Dax, 1870, Am. Jour. Conchology, 2d ser., vol. 6, pt. 2, pp. 154 and 162. (Described.)

Ungula Pander, Dat, 1877, Bull. U. S. Nat. Mus. No. 8, p. 75. (Discusses date of publication of Ungula Pander,
Ungula Rose, and Obolus Eichwald.)

Obolus Eichwald, Zrrret, 1880, Handbuch der Palzeontologie, Bd. 1, Abth. 1, p. 664. (Described in German.)

Obolus Eichwald, Davipson, 1883, British Fossil Brachiopoda, vol. 5, pt. 2, p. 218. (Mentioned in discussion of
Suphonotreta.)

Ungulites QuENSTEDT, 1885, Handbuch der Petrefactenkunde, Aufl. 3, p. 756. (Characterized in German.)

Obolus Eichwald, OratEeRt, 1887, Manuel de conchyliologie, by Fischer, p. 1261. (Described in French, with
figures of ‘‘O. davidsoni Salter” and ‘‘ 0. politus Kutorga.’’)

Obolus Mickwi1z, 1892, Mélanges géol. et paléontol. tirés du Bull. Acad. imp. sci. St.-Pétersbourg, vol. 1, pp. 57-64.
(Described and discussed in German.)

Obolus MatrHEw, 1892, Trans. Roy. Soc. Canada, Ist ser., vol. 9, sec. 4, No. 5, pp. 43-44. (Translates the descrip-
tion given by de Verneuil, 1845, p. 290.)

Obolus Hichwald, Hatt and CrarKe, 1892, Eleventh Ann. Rept. State Geologist New York for 1891, pp. 242-243.
(Described and discussed.)

Aulonotreta Kutorga, Hatt and CLARKE (in part), 1892, idem, pp. 243-244. (Described and discussed. As discussed
the genus includes species referred to both Obolus and Obolus (Acritis).)

Obolus Eichwald, Hatt and Crarks, 1892, Forty-fifth Ann. Rept. New York State Museum, for 1891, pp. 558-559.
(Copied from Hall and Clarke, 1892a, pp. 242-243.)

Aulonotreta Kutorga, Hatt and Crarke (in part), 1892, idem, pp. 559-560. (Copied from Hall and Clarke, 1892a, pp.
243-244 )

Obolus Hichwald, Hatt and Crarxke, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, pp. 80-81. (Described
and discussed.)

Aulonotreta Kutorga, Hatt and CLARK (in part), 1892, idem, p.82. (Described and priority of generic references, etc.,
discussed. As discussed the genus includes species referred to both Obolus and Obolus (Acritis).)

Obolus Hichwald, Hatt and CrarKe, 1892, idem, pp. 337-339. (Gives a translation of Mickwitz’s diagnosis, 1892,
and discusses genus. )

Obolus Hichwald, Mickwirz, 1896, Mém. Acad. imp. sci. St.-Pétersbourg, 8th ser., vol. 4, No. 2, pp. 1-133. (These
pages contain a general discussion of the genus and its relations, in German, the actual diagnosis of the genus
being given on pp. 127-129.)

Obolus (Euobolus) Micxwirz, 1896, idem, pp. 129 and 133. (Characterized in German, on p. 129, as a new subgenus.)

Obolus Hichwald, Watcort, 1898, Proc. U. 8. Nat. Mus., vol. 21, pp. 385-386. (Genus and type species discussed.)

Obolus Eichwald, Waxtcorr, 1901, Proc. U. 8. Nat. Mus., vol. 23, pp. 681-683. (Described and discussed, translating
a portion of Mickwitz’s description, 1896, pp. 118-121.)

Obolus Eichwald, MatrHew, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, p. 135. (Characterized
and discussed. )

Obolus (Hoobolus) MattHEw (in part), 1903, idem, pp. 135-136. (Characterized asa new subgenus. One of the three
species referred to the subgenus belongs with Obolus and the remaining two belong with Lingulella.)
eco” Watcort, 1908, Smithsonian Misc. Coll., vol. 53, No. 4, Pl. XI, and pp. 142 and 144. (Classification

Diagnosis (mainly after Mickwitz [1896]).—Shells nearly equivalve, equal-sided, moder-
ately convex, subcircular, transversely or longitudinally ovate, in some species subtriangular
or subrectangular.

Shell substance calcareocorneous, structure foliated; the layers of calcium phosphate alter-
nating with homogeneous, horny lamellz are traversed by microscopic canals, which in their
main direction are perpendicular to the plane of stratification; the inner layers and lamelle
are more or l2ss oblique to the thin outer layer over the central and posterior portions of the
valves, and strongly so with the short lamelle of the anterior and lateral parts. Surface
shining as if varnished, with concentric and usually radial striation, varying from bare visibility
to deeply incised concentric folds and radial ribs. Color of shell dark grayish blue to black,
when in a state of decomposition dark reddish brown to whitish. Front and side margins
usually thin, sharp-edged, fragile, lying in the same plane with the hinge margin, which is
greatly thickened inside. Area mainly in the plane of the edge of the valve, in the ventral valve
triangular, owing to the somewhat projecting beak, in the dorsal valve rounded at the point,

372 CAMBRIAN BRACHIOPODA.

in both striated parallel to the base, and traversed, from the point of the beak on, by the more or
less diverging lines of folding of the areal lamellz and a strongly marked pedicle furrow.

Visceral area (splanchnoceele) on the ventral valve restricted to the back part, in the dorsal
valve drawn far forward into the vascular area (brachioceele) and strongly indented laterally;
in both valves it extends backward up close to the base of the visceral (splanchnoceelic) part of
the area, which is bounded by the flexure line (folding of the area lamella). The edge of the
mantle of the beak part is restricted to the side areas (pleuroceles), appearing between the
flexure lines of the area lamelle.

Anterior part of the thickened postertor half of valve slopes down to the middle of the
valve, forming in the ventral valve a line concave to the beak, in the dorsal valve asinus. The
lateral parts of the thickening are drawn out into thin side edges. In front of the base of the area
is asmall median septum, which in the dorsal valve for the most part is less prominent, but in both
is often hardly perceptible by reflected light as an almost invisible crest. Beginning at the
median septum, there are in each valve two gradually deepening grooves for the main vascular
canals, which intersect the thickened part parallel to the edge of the shell. In the dorsal valve
these grooves combine with the sinus from the calcareous ridge in forming two projections
pushing themselves like horns into the middle of the valve. The traces of the main vessels of
the mantle lobes in the continuation of the visceral (splanchnocelic) vascular grooves are
subparallel and project into the vascular (brachioceelic) parts of the valves, in the ventral
valve terminating with their anterior ends in the peripheral vascular canal, in the dorsal valve,
shortly before reaching the vascular canal, bending about into the interior of the shell, and
vanishing at the scars of the anterior lateral muscles. The peripheral vascular canals in both
valves run along their edge from one side area (pleurocele) to the other. Traces of secondary
vessels radiate in great number from the grooves of the main vessels toward the peripheral
canals and into the middle of the shell.

In the median line of the ventral valve, between the median septum and the anterior edge
of the thickened part of the shell, there is a deep, heart-shaped pit, with its point directed
forward and having a shallow median groove. In the cavity of the dorsal valve there is a more
or less pronounced median ridge, extending into the anterior part of the valve and divided
longitudinally by a shallow median furrow.

On each valve there are six pairs of muscular scars, and in the ventral valve in front of
the pedicle furrow there is the unpaired scar of the. pedicle muscle. The umbonal scars are
close to the base of the area, in the ventral valve divided, inclosing the scar of the pedicle
muscle between them, in the dorsal valve confluent in the median line of the valve. The scars
of the central pair of muscles are placed about centrally in both valves; in the dorsal one they
are isolated on the inner sides of the ends of the hornlike projections; in the ventral valve they
are united with the scars of the outside and middle lateral muscles, on both sides of the anterior
part of the heart-shaped pit. The transmedian muscles are undivided; their scars in both
valves are close to the base of the area in the line of prolongation of the flexure lines. The
anterior lateral muscle scars of the ventral valve adjoin the transmedians, overlapping them a
little on the outside; in the dorsal valve they are isolated, pushed far forward toward the frontal
margin and situated at the anterior end of the median crest separating them. The scars of the
second pair, the middle lateral muscles, in the ventral valve are combined with those of the
central and outside lateral muscles at the point of the heart-shaped pit; m the dorsal valve
they blend with those of the outside lateral muscles and lie against them on the inner sides of
their anterior ends. Finally the scars of the third pair, the outside lateral muscles, in the
ventral valve are combined with those of the central and middle lateral muscles and lie on the
outer sides of the former, while in the dorsal valve they are united with those of the middle
lateral muscles and lie obliquely outward before the scars of the transmedian muscles. In both

valves the parietal band closely circumscribes all muscle scars externally, crossing the furrows ©

of the main vessels and entering the visceral (splanchnoceelic) part of the area at its base on a
line with the flexure lines.

The study of a series of the interior of the ventral valve of Obolus apollinis (Pl. VII) shows
that the arrangement of the point of attachment of the middle (k) and outside (1) laterals and

OBOLIDZ. 373

central muscle scars (h) varies considerably in the different specimens. Mickwitz’s diagram-
matic figure shows the middle lateral scars (k) to be the smaller and situated close to the
median line. This, however, is not. the case in all specimens. In Plate VII, figure 9, the
middle lateral (k) is the larger and the two other scars are arranged quite differently from
those in Mickwitz’s diagrammatic figure. In Plate VII, figure 5, the growth of the shell has
crowded all three of the muscle scars so that they are arranged in transverse lines. In Plate VII,
figure 4, they occur up on the side of the visceral cavity (v), the central scars (h) occupying the
greater portion of the space, the outside laterals (1) being crowded forward, and the middle
laterals (j), which are so large in figure 9, are scarcely to be determined at the inner angle in
figure 4. In Plate VII, figure 3, the points of attachment of the scars are on a ridge, and they
present no points of similarity to the position assigned in the diagrammatic figure of Mickwitz,
nor to the positions in Plate VII, figures 9, 4, and 5. The points of attachment are sunk deep
into the ridge, and on this account it is impracticable to distinguish between the central (h) and
middle lateral (k) scars. In figure 1 the scars are also on a high ridge. They are slightly
depressed and apparently range very much as in Plate VII, figure 5, except that the middle
laterals (k) are nearer the median line. It does not appear to be possible to distinguish the
centrals.

Type.—O. apollinis Hichwald.

Observations.—It is stated by Hall and Clarke [1892c, p. 339] that Mickwitz did not obtain
his results from the type specimens of Obolus apollinis, but from a hitherto undescribed form,
Obolus quenstedti. This is true [see Mickwitz, 1890, p. 60, footnote], but in his final work
[1896, p. 128] Mickwitz diagnoses the genus and cites Obolus apollinis as the type. He says
[1896, p. 25]:

A more accurate study of the greatly increased material has convinced me that O. quenstedit can not be maintained
as a species, since it is merely the terminal link of a series of variations which, like var. maximus and ingricus, can be
traced back to O. apollinis. Thus, the typical species remains O. apollinis Eichwald.

Mickwitz [1896] has given in his exhaustive memoir on Obolus a very complete historical
sketch and full description of the genus and its subgenera so far as known to him. The study
was conducted with such care and thoroughness and the material was so well preserved that
our present knowledge of the adult shell of Obolus is nearly as complete as that of the adult
shell of the recent Lingula. The student is referred to the memoir of Mickwitz for the literature,
history, and geology of the Cambrian formations of the eastern Baltic region of Russia, for a
minute description of the external and internal characters of the shells of the Baltic species
of Obolus and of the relations of Obolus to Lingula and Obolella, and for detailed observations
on Obolus and its subgenera as known to him.

Obolus and Lingula.—After studying the species from American rocks and a very good series
from the typical localities in Russia, I am not prepared to agree with Mickwitz that Obolus:
should be referred to the Lingulide. In figure 34 the interior of the valves of Obolus and Lingula,
may be compared.

Li} Y)
MY
<7
Gs

S eed
= = h
= =
z Sa
Zz S
z S
Z 8
PA Sa
Z N
Z N
Z SN
Zz NS
Z \
Z N
Z N
: S
S
N
Gj WW
w POTTY
a! !
O
Obolus apollinis quenstedti Mickwitz.
I. Splanchnoccele. d. Canals of principal vessels.
Il. Brachioccele. e. Peripheral vascular canal.
II. Pleuroccele. f. Secondary vascular canals.
a. Pedicle furrow. g. Umbonal muscle.
b. Parietal band. h. Central muscles.
ec. Heart-shaped pit. i. Transmedian muscles.
Lingula anatina Bruguiére.
b. Parietal band which bounds | h. Central muscles.
the splanchnoceelic chamber i. Transmedian muscles.
in both valves. j. Anterior lateral muscles.
ec. Liver. k. Middle lateral muscles.
‘d. Genitalia. 1. Outside lateral muscles.
e. Intestine. m. Pleurocceles.
f. Termination of intestine. n. Vessels of pleurocceles (exag-
g. Umbonal muscle. gerated).

374

After Mickwitz [1896, figs. 6a—b, p. 79].

After King [1873, Pl. II, figs. 1 and 2].

1 <=
vs Z
LB
IIL. (f/

Lif

pa

My,

Ul,

ll]

unt

f
lif

=|

z

=

Sz

ZZ

=

i

Ss

ZS

Z

SS

hs
Pp

J
q

iim :

U/
Ss

UM UL

di
WV,
S

LI).

\.

D

FIGURE 34.—Interiors of valves of Obolus and Lingula.
A, Ventral valve; B, dorsal valve.

j. Anterior lateral muscles.
k. Middle lateral muscles.
1. Outside lateral muscles.
m. Median septum.

n. Lateral septa.

o. Sinus.

C, Ventral valve; D

p. Primary vessels of brachio-
ccele.

q. Secondary vessels of brachio-
ccele (those passing from the
inner side of the primaries
may be called ingoers and
those on the outer side out-
goers).

p. Median ridge.

q- Hornlike projections.

s. Pedicle muscle.

u. Flexure lines of area lamelle.

, dorsal valve.

u. Setal band (the pedicle is not
represented, as it would ob-
scure the continuation of this
band in the rostral region).

y. Inner edge of setal band (an-
swering also to the line of
vascular constriction).

w. Outer edge of setal band.

x. Sete.

OBOLIDA. a10

The points of similarity between Obolus and Lingula, as described by Mickwitz, are:

1. Chemical constitution and microscopic structure.

2. Position of the umbonal muscle in the dorsal valve.

3. Arrangement of the vessels of the circulatory system. Mickwitz [1896, p. 121] says:

Issuing between the same muscle scars (j-l, h in the ventral valve; 1, i, k-h in the dorsal valve) from the splanch-
noceele, two main vessels extend in each valve into the fore part of the mantle lobes and branch inward and outward
into numerous secondary vessels. The only difference in the arrangement of the vessels consists in this, that in Lingula
the main vessels of the two valves empty into the peripheral canal, while in Obolus this takes place only in the large
valve. In the dorsal valve the main vessels, shortly before reaching the peripheral canals, bend into the interior of
the valves and end at the scars of the anterior lateral muscles.

4. General arrangement of the muscle scars. These are essentially the same, the points
of difference being of a generic character.

The points of difference between the two genera are:

1. The areas of the valves.

2. Attachment of the pedicle muscle. In Lingula the muscle 1s attached back of the scar
of the umbonal muscle of the ventral valve, whereas in Obolus it is situated between the divisions
of the scar of the umbonal muscle of the ventral valve.

3. Bipartition of certam muscles. Mickwitz says [1896, pp. 118-121]:

Besides the somewhat unlike arrangement of some scars, to which we shall presently return, the bipartition of
certain muscles constitutes the most characteristic difference in the internal organization of the two genera. The
umbonal muscle of Obolus, which is divided in the ventral valve [gg, fig. 34A], is undivided in Lingula [g, fig. 34C]
while conversely the two transmedian muscles of Lingula [ii, fig. 34C], one of which is divided throughout its length,
are represented in Obolus by a pair of undivided muscles [i, fig. 34A].

The position of the umbonal muscle is the same in the two genera; at most it is somewhat crowded away from
the base of the area in Lingula, because of the pedicle muscle. On the contrary, the transmedian muscles, besides
their bipartition, present other differences. In Obolus the scars of that pair of muscles on the ventral valve are com-
bined with those of the anterior lateral muscles [ij, fig. 34A], while in the corresponding shell of Lingula, though lying
in a similar position, they are separated from the anterior lateral muscles. With the dorsal valves the-case is reversed.
Obolus shows the scars of the pair of muscles in question isolated fi, fig. 34B], while in Lingula they are united with
those of the middle and outside lateral muscles [i, k, and 1, fig. 34D].

The scars of the two last-named muscles on the dorsal valve of Obolus [k and 1, fig. 34B] are combined in a manner
analogous to those of Lingula, so that the whole difference in the arrangement of the scars in question (aside from the
bipartition of one transmedian muscle in Lingula) consists in the reversal of their combination. In Obolus, on the ventral
valve, the scars i and j are united, in Zingula they are separated; in Lingula, on the dorsal valve, i k, and | are united,
while in Obolus they are separated.

The scars of the anterior lateral muscles of the dorsal valve have a closely similar position in the two genera,
except that in Obolus they are moved farther forward and are separated by the median ridge (p), while in Lingula
they are nearer to the center of the valve and are united [j, fig. 34D].

The other scars of the lateral muscles on the ventral valve of Obolus also are quite analogous in their position to
the corresponding scars in Lingula [k, 1, fig. 34C]. True, in their case also small displacements and changes of form
occur, but yet I am unable to attach to these any special value. The two genera show the scars of the outside lateral
muscles [l, figs. 834A and 340] combined with those of the central muscles [h, figs. 34A and 34C], but we have
seen that in some species of the genus (0. triangularis, O. pander1, and some species of the subgenus Schmidtia) the
first-named scars are separate from those of the central muscles and change their subtriangular form, being drawn out
backward into a rounded form, more like that in Lingula. ‘The scars of the middle lateral muscles (k) of the ventral
valve, on the contrary, are only in Hichwald’s genus combined with those of the central muscles (h), while in Lingula
they are separated. It is probable, however, that some species of the above-named subgenus share this peculiarity
with Lingula.

Finally, the scars of the central muscles of the two genera differ merely by their somewhat different form in the
ventral valve and by their somewhat different position to the axis of symmetry on the dorsal valve. It was pointed
out, however, in speaking of the central muscles of Obolus that the backward-protracted points of the subtrapezoidal
scars in the ventral valve of the typical species (as well as those of the outside lateral muscles) are lacking in the species
of the subgenus Schmidtia, so that even in regard to form there is an agreement with Lingula. In the dorsal valve of
Obolus the elliptic scars of the central muscles are parallel to the major axis of the valve or somewhat converging behind
[h, fig. 34B], while in Lingula they are strongly convergent anteriorly [h, fig. 34D].

To the altered position of the muscle scars in Obolus corresponds the modified form of the par.etal band. The latter
in both valves of Lingula is rhombic, but in the dorsal valve it is drawn farther forward than in the ventral [fig. 34D].

376 CAMBRIAN BRACHTIOPODA.

In Obolus the parietal band on the dorsal valve extends still farther toward the frontal edge than in Lingula, and in
its posterior part is more markedly bent inward from both sides, producing a characteristic unequally three-lobed
figure [fig. 34B]. The parietal band of the ventral valve of Obolus on the contrary is subelliptical in form, and rather
approaches that of Lingula. .

More important than this difference in form of the splanchnoceele is the difference in the form of the mantle lobes
which is manifest from the position of the posterior part of the parietal band. In ZLingula the parietal band is moved
away from the base of the area and thus constitutes a narrow space between the two pleurocceles, which space is
occupied by the mantle lobes that extend around the entire beak part of the valves. These mantle lobes of the beak
are in the dorsal valve also covered with mantle bristles, while the border of the mantle of the ventral valve in the
splanchnoceelic part of the area (deltidium, King) is free from bristles [fig. 34C]. In Obolus on the contrary the pos-
terior part of the parietal band is close to the base of the splanchnoccelic part of the area, whose lamelle, as we have
seen, are bent up at right angles to the plane of the valve and therefore could not have been deposited by mantle
lobes resting against the valves. Hence the mantle lobes of Obolus extended only as far as the pleurocceles, and were
lacking, as well as the mantle bristles, in the splanchnoccelic part of the area of both valves. At that point there was
only the muscular wall of the body connecting the two valves, from which the pedicle emerged.

I think that the differences pointed out are sufficient to distinguish Obolus as of distinct
family relations from Lingula, but I must at the same time admit that the transitions from
Obolus to Lingulella and from Lingulella to Lingula are so clearly indicated that it is only by a
somewhat arbitrary decision that species of Lingulella like L. bella (Pls. XIX and XXXVI) can
be referred tothe Obolide. Schuchert [1893, p. 360] creates the family Lingulellidee for Lingulella
and allied forms.

Obolus and Obolella—Authors have compared Obolella with Obolus, and Mickwitz [1896, p.
129] thought that they might possibly be congeneric. The discovery of a pedicle opening at the
beak of the ventral valve of Obolella places the latter with the Acrotretide.

Criteria of subgenera.—The criteria upon which the subgenera of Obolus have been founded
are largely based on the form of the outline of the valves, character of outer surface, thickness
of shell, and, to a more limited extent, the muscular and vascular markings on the interior of
the valves. J was at first mclined to give considerable weight to the position of the sinuses
occupied by the main vascular canals, but further study showed such a gradation in the various
species that efforts to use the character in subgeneric classification were abandoned. The
following table illustrates some of the variations in the position of the vascular smus, and many
more may be found in the figures of Obolus and its subgenera than are indicated in the table
below:

Variation in the position of the vascular sinus of Obolus and its subgenera and Lingulella.

{Roman numerals indicate plates and arabic numerals figures.]

Distance of sinus from center to lateral margin.

Species.
Less than one-half
distance.

Three-fourths dis-

One-half distance. Two-thirds distance. tance.

Obolus:
Spollimise. oy osee Medes osc Seek Sere een eae AVAL deere ee ee Wily 257418) iiss see
SPOUTS Te OS eee ee Tae cee eedas|=scuee aoetee Pe Serco recited
complexus

_| XXII: 9j, 2g.

_| VIL: 1d, le, 1f, 1g, 1h.
a) 2:68 ahi, ij, Me suece eek

prindlei....

hea eee ee as ese aca eins ee Rae eee eee
? rokitzanensis.
schmidti...

Salteni seein sty cect. c oe. sta See ae seen emae ec ene XIII: XIII: 1j, 1m
Obolus (echundtia):
celatus.- =

Crassus: _..| XIV: 4e.

Po eaancadacnebsoncedude soy op eoBbSEoUNScUSEOneees XLVII: 1d,1k,11, 1n.}| XLVII: 1c, 1g....-.-...
eee aosaanoe >IUIDSB EE See se ses POUID ONO se apes ocon ae
euglyphus E
NOVReS bss win sso cspenonesonb cc coaseSaoucesonabousscaes

OBOLIDZ. Be

Variation in the position of the vascular sinus of Obolus and its subgenera and Lingulella—Continued.

Distance of sinus from center to lateral margin.

Species.

Less than one-half . othi - Three-fourths dis-
Ghia, One-half distance. Two-thirds distance. ana,

Lingulella:

_.| XXXV: 8a.

dubia...
ferru; inea

_.| XXII: 14.
-| XXV: ig, th, 1i.

eerie ee oan --| XXIV: 2a.

winona convex:
Lingulella (Lingulepi:
acuminata XLII: 1g, 1h; XLI:1a.) XLII: le
EIB Ui aa ee Pea see ena tciane she cman see seece wen PGUINNE sy Ibis eee ae XLIII: 1x, ly

GREW ENS 5 onc So vadaood meas pode ope bassbeRSS dee SSaeos GUID Bale Se SauBAbGs ol Sasa SoeRns Sana aaenoodee XLIV: 1n:

Subgenera of Obolus.—Acritis Volborth [1869, p. 212] is ornamented with concentric lines
which are elevated, irregular, and undulating. The valves are strongly arched and massive;
the visceral area (splanchnoccele) small and short, and the pedicle furrow conical and deeply
impressed in the cardinal area. Type: Obolus (Lucina) antiquissimus Eichwald (Pl. XIII, fig.
3, and Pl. XV, figs. 1, la-c).

Bréggeria Walcott [1902, p. 605] has the typical ovate outline of Obolus, but differs from
Obolus and its other subgenera in having a very deep visceral depression (splanchnoccele) in
both valves, and in its minutely papillose imterior surface. Type: Obolella salteri Holl (PI.
XIII, figs. 1, la-n, and Pl. XV, figs. 4, 4a-d).

Eoobolus Matthew [1903, p. 135] was proposed for certain species of Obolus in which the
central muscle scars and anterior scars were arranged in a more or less quadrate manner, as in
Obolus selwyni (Matthew) (Pl. XXXVI, figs. 2a and 2b). I find that the specimen illustrated by
Matthew [1903, Pl. VIII, fig. 2d] was distorted. It is figured in Plate XX XVI of this monograph
(fig. 2a), and a second distorted specimen in figure 2b. A more perfect specimen is illustrated
in figure 1g, and the changes in position of the muscle scars in the center of the dorsal valve
may be seen by comparing Plate XXXVI, figures 2a and 1g; Plate XX XVII, figure 1c; Plate
XXVIII, figures ih and 1g; Plate XXXI, figure 6e; Plate XVII, figures 1h and 1j; Plate X XI,
figure 2a. A study of the figures cited and many others shows that the position of the central
muscle scars and anterior lateral scars is not a character of sufficient importance and value
upon which to found asubgenus of Obolus. On this account Hoobolus is considered as a synonym
of Obolus.

Euobolus Mickwitz [1896, p. 314] was elaborately described as a subgenus of Obolus by
Mickwitz, who referred to it all species showing radial striation. He says [1896, p. 128]:

In grouping the species by their distinctive marks, two great divisions become apparent. One of them shows,
besides the concentric striation of the outer surface of the shell, peculiar to all Obolus species, also a radial striation
which is lacking in the others. Thus, while the concentric striation is a general characteristic, which, nevertheless,
by differences in development, furnishes useful specific features, the radial striation, due to a different condition of the
edge of the mantle (no matter whether this be due to the mantle bristles or to the circulatory vessels), constitutes a
group character. For this reason all radially striated Oboli, whose other characters also show a certain agreement in
other respects, were united into a subgenus Huobolus. Furthermore, the concentric striz of certain species showed

remarkable variations, which also indicate a peculiar organization of the edge of the mantle. The species O. siluricus
and antiquissimus show this striation running parallel on the growth lamelle corresponding to a period of vegetation,

378 CAMBRIAN BRACHIOPODA.

while in all other Obolus species they converge. As the species mentioned differ from each other considerably in other
respects, it seemed to me necessary to assign them to special subgenera, Thysanotos and Acritis, ‘The remaining species
also fall into two groups differing from each other in many ways, one of them, Schmidtia, approaching more the typical
Obolus, the other, Leptembolon, being closer to Lingula.

The delimitation of the species presents similar difficulties to those in the allied genus Zingula. The differences
are manifest, but are difficult to express in words. This is true especially of some species of the subgenera Huobolus
and Schmidtia.

The introduction of the subgenus Huobolus for the radially striated Oboli does not appear
to be necessary for a proper classification of the genus. If the radially striated species are
considered to be the typical form of Obolus, then those differing from it to a sufficient degree may
be referred to a subgenus. The genus Lingulella has only radially striated forms meluded
within it, and this in part includes species that otherwise would be referred to Euobolus. To
this extent Euobolus is a synonym of Lingulella.

I have endeavored to identify in material from the typical localities the varieties of
Obolus and its subgenera described by Mickwitz, but find it practically impossible in nearly
all cases. They may be found of value to the special student, but they are not of service in
studies of the Cambrian fauna. Such minute discriminations would lead to an endless amount
of detailed description if followed in the study of the faunas as they occur in the collections
before me.

Fordinia Walcott [1908d, p. 64] includes specimens that have a Lingulella-like outline, with
the development of a tendency to form a platform or thickening im the valves. Type: Obolus
(Fordinia) perfectus Walcott.

Leptembolon Mickwitz [1896, p. 199] is referred to in this monograph as a subgenus of
Lingulella.

Lingulepis Hall [1863, p. 129] is referred to in this monograph as a subgenus of Lingulella.

Lingulobolus Matthew [1895b, p. 260] is a Lingulella-like form, with a thick, strongly arched
shell and surface marked by subimbricated wavy concentric lines. Type: Lingulella? affinis
Billings (Pl. XVI, figs. 1, la-e).

Mickwitzella Walcott [1908d, p. 70] is an Obolus with strong, uniformly curved concentric
strie, with the lamelle of growth fringed along their anterior (external) edges. Type: Obolus
siluricus Hichwald (Pl. XV, figs. 1, la-c).

Monobolina Salter [1866b, p. 334] has been referred to as a subgenus of Obolus by Matthew
[1902b, p. 98]. It differs from Obolus in having a platform in the ventral valve of the same type
as that of Elkania (Pl. LI, figs. 1, 1a, and 4b) and is clearly not descendant from Obolus or
generically connected with it. Salter [1866b, p. 334] placed Monobolina as a section of the
genus Obolella Billmgs. ‘

Palzobolus Matthew [1899, p. 201] shows concentric lines which are elevated and slightly
irregular. The visceral area (splanchnoceele) is large and elongate, and the main vascular canals
are close to the visceral area (Pl. XXXII, figs. 5,5a-g). The surface of Palzxobolus is of the same
type as that of Acritis, but the visceral cavity and vascular canals differ materially in the two
forms. Type: Palzobolus bretonensis Matthew.

Schmidtia Volborth [1869, p. 208] is a Lingulella-like shell without radial striation. All the

species are small and as the concentric striation is very fine the shell surface is nearly smooth.
Type: Schmidtia celata Volborth (Pl. XIV, figs. 1, la-c).

Westonia Walcott [1901, p. 691] 1s a Lingulella-lke form distinguished by peculiar, transverse,
semi-imbricating, ‘‘ripple-embossed”’ lines that cross both the concentric and radiating strie.
Type: Lingula aurora Hall (PI. XLVI).

Stratigraphic range of Obolus and subgenera.—Obolus has a stratigraphic distribution rang-
ing from the limits of the Olenellus fauna, through the Middle Cambrian or Olenoides fauna and the
Upper Cambrian or Dikellocephalus [Olenus] fauna, into the base of the Ordovician fauna. Obolus
proper has not been found below the upper portion of the Lower Cambrian. The youngest
species of the genus are the largest, and also have certain strongly marked characteristics which

OBOLID. 379

have grouped them under the subgenus Lingulobolus. The species referred to Obolus from the
Lower Cambrian include Obolus prindlei (P|. XX VII, figs. 3, 3a-e) which is intermediate in form
between Obolus apollinis (Pl. XIV, figs. 6, 6a) and the type species of the genus Lingulella,
L. dawisi (Pl. XXXII, figs. 6e, 6f). Obolus smitha (p. 416) is a typical form of Obolus, while Obolus
parvus (p. 408) is a minute form of which only the exterior is known.

Of the 77 species and 11 varieties from the Cambrian referred in this memoir to Obolus and
its subgenera, 4 species occur in the Lower Cambrian, 46 species and 5 varieties in the Middle
Cambrian, 43 species and 7 varieties in the Upper Cambrian, and 10 species in the passage beds
between the Cambrian and Ordovician. From the Ordovician 23 species are described. (See
table of species, pp. 110 and 113.)

Acritis is represented in the Upper Cambrian of Russia by the type species. A species is
doubtfully referred to it from Nevada.

Bréggeria is represented by one species. This is found in the Upper Cambrian and the pas-
sage beds to the Ordovician of the North Atlantic province of Hurope and eastern North America.

Fordinia includes species from the Middle and Upper Cambrian of Utah and Nevada.

Lingulobolus is represented by two species occurring in the Lower Ordovician rocks of New-
foundland and in conglomerate pebbles in Massachusetts.

Mickwitzella is confined to one species identified from the passage beds between the Upper
Cambrian and the Ordovician of Russia.

Palzobolus is represented by a single species from the Middle Cambrian of Nova Scotia.

Schmidtia is represented in the Upper Cambrian ‘‘Obolus” sandstones of Russia by four
species, which form a peculiar and restricted local group.

Westonmia has its greatest development in the Middle Cambrian, where thirteen species and
one variety occur. Six species are known from the Upper Cambrian, one from the passage
beds to the Ordovician, and five in the lower portion of the Ordovician.

Geographic distribution of Obolus and subgenera.—In Europe Obolus proper appears to be
limited to the type area in northwestern Russia, where it reaches its greatest development, and
to a few limited localities in Bohemia and Sweden. Its subgenera, especially Westonia, have a
wide distribution, the latter having been found in Russia, Bohemia, many localities on the
Scandinavian Peninsula, England, and China.

Only one form is known from Sweden—0O. schmalenseer (Walcott). The genus (or one of its
subgenera) appears to be present in the Cambrian of Argentina, and four species have been
described from eastern China—0O. chinensis (Walcott), O. minimus Walcott, O. obscurus Walcott,
and O. shansiensis Walcott. It is on the North American continent that Obolus reaches its
greatest development outside of its original localities in Russia. It is widely distributed and
often occurs in great numbers at favorable localities. It occurs along the lines of the Appa-
lachian Range from Newfoundland, Cape Breton, and New Brunswick to Tennessee. It is
represented in the northern Mississippi Valley region, in the isolated uplifts of Cambrian rocks
in the Black Hills of South Dakota, the Ozark Mountains of Missouri, the Llano Hills of central
Texas, and westward in Wyoming, Montana, Utah, and Nevada.

Of the species im this memoir that are placed under Obolus from Bohemia, O. feistmanteli
(Barrande) and O. complexus Barrande are probably true representatives of the genus, but the
following species are exceedingly doubtful in their generic identification:

Obolus ? advenus Barrande.
Obolus ? ancillus (Barrande).
Obolus ? bayaricus (Barrande).
Obolus ? minor Barrande.
Obolus ? mirandus (Barrande).
Obolus ? palliatus Barrande.
Obolus ? rokitzanensis Barrande.

This is true also of the two forms from Sardinia: Obolus? zoppi Walcott, and 0.2 meneghinia
Walcott.

380 CAMBRIAN BRACHIOPODA.

The species of the genus and its subgenera recognized by Mickwitz [1896] im Russia are:

Obolus (Acritis) antiquissimus (Eichwald). | Obolus (Schmidtia):
Obolus (Euobolus): acuminatus Mickwitz.
apollinis Hichwald. acuminatus alatus Mickwitz.
apollinis ingricus (Eichwald). acuminatus humeratus Mickwitz.
apollinis maximus Mickwitz. acuminatus subtriangularis Mickwitz.
apollinis quenstedti (Mickwitz). | celatus (Volborth).
eichwaldi Mickwitz. celatus orbiculatus Mickwitz.
elegans Mickwitz. celatus preecisus Mickwitz.
panderi Mickwitz. crassus Mickwitz.
schmidti Mickwitz. crassus angulatus Mickwitz.
triangularis Mickwitz. obtusus Mickwitz.
triangularis inornatus Mickwitz. obtusus acutus Mickwitz.
volborthi Mickwitz. 4 obtusus ellipticus Mickwitz.
Obolus (Leptembolon) linguleeformis Mickwitz. obtusus extenuatus Mickwitz.
Obolus (Mickwitzella) siluricus (Eichwald). obtusus latus Mickwitz.

obtusus longus Mickwitz.
obtusus minutus Mickwitz.

OxBoLus AcADIcUS Walcott.

: Plate XI, figure 5.

Obolus acadica Waucott, 1905, Proc. U. S. Nat. Mus., vol. 28, pp. 324-325. (Characterized and discussed as below as

a new species.)

Only interiors of the dorsal valve of this species occur in the collections made by Loper
on McNeil Brook in 1900. The material was provisionally referred to Lingulella concinna
Matthew, but the broadly rounded subquadrilateral form of the dorsal valve seems to
distinguish it from that species and also from Obolus (Palzxobolus) bretonensis (Matthew).

The visceral area is narrow, extending a little in advance of the center of the valve. The
main vascular trunks are narrow and widely separated. They belong to the submarginal sroup
and are thus quite unlike those of O. (P.) bretonensis., The exterior surface and ventral valve
are unknown. ;

The specific name is derived from Acadia, the original name for Nova Scotia, in which the
species occurs.

ForMATION AND LOCALITY.—Upper Cambrian: (3h) Shale and shaly limestone on McNeil Brook, 1.5 miles (2.4 km.)
east of Marion Bridge, eastern Cape Breton, Nova Scotia.

OxsoLtus? ADVENUS Barrande.

l

Plate XII, figures 5, 5a-b.

Obolus ? advena BARRANDE, 1879, Systéme silurien du centre de la Bohéme, vol. 5, pt. 1, Pl. XCV, figs. 1v: 1-2. (No

text reference. Figs. 2A, 1A, and 2B are copied in this monograph, Pl. XII, figs. 5, 5a-b, respectively.)

This species is known to me only by the figures of Barrande [1879b, Pl. XCV, fig. rv] some
of which are copied on Plate XII. The species is of the same type as O. complexus Barrande,
so far as the means of comparison permit us to judge. It occurs at the same relative geologic
horizon as O. complexus.

FORMATION AND LOCALITY.—Lower Ordovician: (308d [Barrande, 1879b, Pl. XCV]) Etage dl, Swarow, Bohemia,
Austria-Hungary.
OxBoLus ANCEPS Walcott.

Plate X, figures 3, 3a-f.
Obolus anceps Watcort, 1898, Proc. U. 8. Nat. Mus., vol. 21, pp. 388-389. (Described and discussed as below as a
new species.)

General form broadly ovate, somewhat subcuneate.. Valves moderately convex. Surface
marked by fine lines of growth, and finer slightly undulating concentric striz; when the outer
layer is exfoliated the outer surface of the inner layer is marked by very fine, radiating strie
and numerous lines of growth; the mner surface of the shell is nearly smooth, judging from a

7

OBOLIDA. a8 1

partial cast in the limestone. The shell is relatively thin and formed of a very thin outer layer
and one or more thin inner layers or lamelle, which thicken the shell from the umbonal
region and toward the front and sides.

A cast of the interior of a dorsal valve that is referred to this species shows that a strong
median ridge was present; also a median septum and a strong main vascular sinus. The area is
short and marked by rather prominent flexure lines, as indicated by the flexures in the transverse
lines of growth.

Observations.—This species might be taken for the young of O. matinalis (Hall) or O. mera
(Hall and Whitfield), were it not for the great difference in the thickness of the shell. It occurs
at a slightly higher horizon at the base of the Pogonip limestone.

FoRMATION AND LOCALITY.—Lower Ordovician (63) Limestone at the base of the Pogonip limestone northeast of
Adams Hill, Eureka district [Hague, 1892, Atlas], Eureka County, Nevada.

Upper Cambrian: (61) Limestone in the Dunderberg shale [Walcott, 1908f, p. 184], a little south of the Hamburg
mine, Eureka district [Hague, 1892, Atlas], Eureka County, Nevada.
OxsoLus? ANcILLUS (Barrande).

/

Ve Plate XII, figure 2.
Lingula ancilla BARRANDE, 1879, Systéme silurien du centre de la Bohéme, vol. 5, pt. 1, Pl. CXI, fig. v1: 3. (No
text reference. Fig. 3 is copied in this monograph, Pl. XII, fig. 2.)

This is a small shell of which we have only the one figure given by Barrande [1879b, Pl. CXI,
fig. yi: 3] from which to express an opinion as to its generic relations. The configuration of the
valve and the lamellose character of.the shell, as indicated by the portions adhering to the cast,
are what has led me to make the provisional reference to Obolus. There are no interior characters
shown in the figure.

FORMATION AND LOCALITY.—Lower Ordovician: (303g [Barrande, 1879b, Pl. OXI]) Etage dl, at Rabenberg,
Bohemia, Austria-Hungary.

OBOLUS APOLLINIS Hichwald.

Text figures 4 and 15, page 299; Plate VII, figures 1-8, 10-17; Plate XIV, figures 6, 6a.

Obolus apollinis ErcHwaxpD, 1829, Zoologia specialis, vol. 1, p. 274, Pl. IV, figs. 5a-b. (Described in Latin as a new
species.) ‘

Ungula plana PANDER, 1830, Beitrage zur Geognosie des russischen Reiches, pp. 59 and 163, Pl. XXVIII, figs. 3a-b,
5a-b. (Characterized in German on p. 59; description of plate on p. 163.)

Ungula plana or convexa PANDER, 1830, idem, p. 163, Pl. XXVIII, figs. 2a-b. (Only the description of the plate
occurs on p. 163.)

Ungula rotunda PanpER, 1830, idem, pp. 59 and 168, Pl. XXVIII, figs. 4a-b. (Characterized in German on p. 59;
description of plate on p. 163.)

Ungula ovata PANDER, 1830, idem, pp. 59 and 154, PI. III, fig. 23 (not Pl. XXVIII, figs. 6a—b, referred to Obolus
(Schmidtia) celatus). (Characterized in German on p. 59; description of plate on p. 154.)

Ungula transversa PANDER (in part), 1830, idem, pp. 59 and 163, Pl. XXVIII, figs. 7a—b, 8a—b? (not Pl. III, fig. 24,
which represents a specimen of Obolus apollinis quenstedti). (Characterized in German on p. 59; description of
plate on p. 163.)

Ungula triangularis PANDER, 1830, idem, pp. 59, 154, and 163, Pl. III, fig. 25, Pl. XXVIII, figs. 9a-b. (Characterized
in German on p. 59; descriptions of plates on pp. 154 and 163.)

Obolus apollinis Ercuwaup, 1840, Jour. Natur- und Heilkunde Medizinischen Akad. St. Petersburg, pts. 1 and 2, p. 167.
(Not seen.)

Orthis ungula von Bucu, 1841, Archiv fiir Mineralogie, Bd. 15, Hit. 1, pp. 7-8, Pl. Il, fig.9. (Described and discussed
in German, as belonging with the “‘ Unguliten.’’)

Obolus apollinis EicHwatp, 1843, Beitriige zur Kenntniss des russischen Reiches, Bd. 8, No. 2, p. 140. (Discussed in
German.)

Obolus apollinis Hichwald, pr VERNEUIL (in part), 1845, Géologie de la Russie d’ Europe, by Murchison, de Verneuil,
and de Keyserling, vol. 2, pt. 3, pp. 290-292, Pl. XIX, figs. 3a-d. (Described and discussed in French; see Mat-
thew, 1892, pp. 43-44, for translation. De Verneuil includes Obolus apollinis ingricus, Obolus (Acritis) anti-
quissimus, and Obolus ( Mickwitzella) silwricus in this species.)

Obolus apollinis Hichwald, Kurorea, 1848, Verhandl. Russ.-kais. min. Gesell. St. Petersburg for 1847, No. 12, pp. 251
and 252. (Discussed in German.)

Aulonotreta polita Kutorea (in part), 1848, idem, pp. 279-282, Pl. VII, figs. 10a-f. (Described and discussed in
German as a new species. The text includes Obolus apollinis, Obolus apollinis ingricus, and Obolus( Mickwitz-
ella) siluricus.)

382 CAMBRIAN BRACHIOPODA.

Obolus apollinis Eichwald, Morris, 1849, Annals and Mag. Nat. Hist., 2d ser., vol. 4, p. 316. (Merely changes generic
and specific reference of Kutorga’s Aulonotreta polita.) ‘

Obolus apollinis Kichwald, Davyipson (in part), 1853, British Fossil Brachiopoda, vol. 1, introduction, No. 3, figs. 51
and 52, p. 136, and Pl. IX, figs. 280-284 (not fig. 285, which represents Obolus (Acritis) antiquissimus). (No text
reference. Figs. 280 and 281 appear to be drawn from the specimens figured by Kutorga, 1848, Pl. VII, figs. 10a
and 10f, respectively; figs. 282, 283, and 284 are drawn from the specimens figured by Kutorga, 1848, Pl. VII,
figs. 10b’, 10c, and 10e, respectively. )

Obolus apollinis ErcawauD, 1860, Lethzea rossica, ancienne période, vol. 1, sec. 2, pp. 925-926. (Described and dis-
cussed in French.)

Obolus apollinis Kichwald, Scamript, 1861, Archiv fiir Naturkunde Liy-, Ehst-, und Kurlands, Ist ser., Bd. 2, p. 218.
(Localities mentioned in German.)

Obolus apollinis Kichwald, Brniines, 1872, Canadian Naturalist, 2d ser., vol. 6, No. 2, p. 218, fig. 7,p.217. (Discussed.
Fig. 7 is copied from Davidson, 1853, Pl. IX, fig. 283.)

Obolus apollinis Eichwald, Brnuines, 1872, Am. Jour. Sci., 3d ser., vol. 3, p. 356, fig. 7, p. 355. (Copy of preceding
reference.)

Obolus apollinis Hichwald, RormER, 1876, Lethzea geognostica, pt. 1, Lethzea paleeozoica, Atlas, Pl. II, figs. 7a-c. (No
text reference. Figs. 7a—c are copied from de Verneuil, 1845, Pl. XIX, figs. 3b, 3a, and 3d, respectively.)
Obolus apollinis Hichwald, Zirret (in part), 1880, Handbuch der Palzontologie, Bd. 1, Abth. 1, p. 664, figs. 488a—e (not
fig. 488d, which represents Obolus apollinis quenstedtr). (No text reference. Figs. 488b and 488c are roughly
copied from Davidson, 1853, Pl. IX, fig. 283, and fig. 52, p. 136, respectively. Fig. 488a appears to be roughly

copied from Kutorga, 1848, Pl. VII, fig. 10a’.)

Obolus apollinis Kichwald, Norriine, 1883, Jahrb. Konig. preuss. geol. Landesanstalt Berlin for 1882, p. 265. (New
locality mentioned in German.)

Obolus apollinis Eichwald, RormeErR, 1885, Paleontologische Abhandlungen von Dames und Kayser, Bd. 2, Hit. 5,
pp. 23-24 (270-271), Pl. I (XXIV), figs. 2a-d. (New localities mentioned in German. Figs. 2b, 2c, and 2d are
copied from de Verneuil, 1845, Pl. XIX, figs. 3b, 3a, and 3d, respectively.)

Ungulites apollinis (Hichwald), QuENsTEDT, 1885, Handbuch der Petrefactenkunde, Aufl. 3, pp. 755 and 756; fig. 262,
p. 755, and Pl. LVIII, figs. 56-57. (Characterized in German.)

Obolus apollinis Eichwald, GacEL, 1890, Beitr. zur Naturkunde Preussens, von Physikal.-oekonom. Gesell. Kénigs-
berg, 6, pp. 21-22, Pl. I, figs. 16, 16a-c. (Described in German. Figs. 16, 16a-c are very rough copies of the
figures given by Roemer, 1885, Pl. I (XXIV), figs. 2a-d, respectively.)

Obolus apollinis Kichwald, MatrHEew, 1892, Trans. Roy. Soc. Canada for 1891, Ist ser., vol. 9, pp. 43-44. (A translation
of the description given by de Verneuil, 1845, pp. 291-292.)

Obolus apollinis Kichwald, Haut and CiarKe, 1892, Eleventh Ann. Rept. State Geologist New York for 1891, figs. 247
and 248, p. 242. (Notext reference. Fig. 247is copied from Davidson, 1853, Pl. IX, fig. 283; fig. 248 is copied
from Kutorga, 1848, Pl. VII, fig. 10b’.)

Obolus, apollimis Hichwald, Hatt and CuarKe, 1892, Forty-fifth Ann. Rept. New York State Museum for 1891, figs.
247 and 248, p. 558. (Copy of preceding reference.)

Obolus apollinis Kichwald, Hatt and CLarks, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, footnote, p. 80,
and figs. 33-34, p. 80. (Figures representing species discussed. Fig. 33 is copied from Davidson, 1853, Pl. 1X,
fig. 283; fig. 34 is copied from Kutorga, 1848, Pl. VII, fig. 10b’.)

Obolus apollinis Hichwald, Mickwirz, 1896, Mém. Acad. imp. sci. St.-Pétersbourg, 8th ser., vol. 4, No. 2, pp. 133-137,
Pl. I, figs. 1-14. (Described and discussed in German; see below for translation of the essential parts.)

Obolus apollinis Hichwald, Waucort, 1898, Proc. U. 8. Nat. Mus., vol. 21, Pl. X XVI, figs. 3-6. (No text reference.
The specimens represented by figs. 3-6 are redrawn in this monograph, Pl. VII, figs. 10-13, respectively.)
Obolus apollinis Eichwald, MoBerG and SEGERBERG, 1906, Medd. frin Lunds Geol. Faltklubb, Ser. B, No. 2 (Aftryck
ur K. Fysiografiska Sillskapets Handl., N. F., Bd. 17), p. 65, Pl. III, figs. 1-3. (Specimens from new localities

discussed in Swedish.)

Obolus apollinis Eichwald, WestERGARD, 1909, Medd. fran Lunds Geol. Faltklubb, Ser. B, No. 4 (Aftryck ur K. Fysio-
grafiska Sillskapets Handl., N. F., Bd. 20), p. 56, Pl. Il, figs. 14-16. (Localities mentioned in Swedish. Figs.
14-16 are copied from Moberg and Segerberg, 1906, Pl. III, figs. 1-3, respectively.)

Obolus apollinis being the type of the genus, I have reproduced the diagnosis by Mickwitz
[1896, p. 133] with the accompanying remarks:

The series of forms comprised under O. apollinis, and connected with each other by many transitions, show such
departures in their extreme forms that an abundant material was necessary in order to show that they belong together.
With the increasing number of different forms there was an increasing difficulty in grouping them and in deciding
the question as to which of these many forms were to be regarded as species and which as varieties. The small oval
valves corresponding to Hichwald’s original in the Zoologia specialis show the generic characters much less pronounced
than many of the forms described below. Still Eichwald’s conception was retained and merely somewhat amplified
by the incorporation of a small rounded form, because this form showed closer relation to Eichwald’s original than to
the more divergent large forms described as varieties.

OBOLIDA. 383

Diagnosis: Shells flat, outline oval to rounded, tip of beak of the large valve somewhat drawn forward and some-
what curved inward. Concentric and radial striation faint and irregular, the latter somewhat unpronounced, at times
lost In an irregularly rent shell surface, but always recognizable at the posterior edges of the shell. Front and side
edges thin, sharp, brittle, lying in the same plane as the thickened edges of the beak. Area in the median line some-
what concave; pedicle furrow distinctly developed, slightly tapering toward the apex of the beak. Lines of folding
of the area lamellz slightly concave to the median line of the valve and converging into the apex of the beak. The

’ thickening of the posterior half of the valve is massive; the slope of the thickening down to the middle of the valve,
in the large valve, shows longitudinal strize and transverse traces of the secondary vessels. The traces of the main
vessels in both valves are broad and flat and on both sides marked at the bottom by narrow grooves. The grooves of
the secondary vessels, radiating into the interior of the valves, are rectilinear, unbranched, and at right angles to the
grooves of the main vessels. The central pit has the shape of the conventional heart, opens into the brachioccele through
the median furrow and shows longitudinal striz at its posterior edge. The muscular attachments of the combined
outside lateral and central muscles of the large valve are drawn out into furrows toward the beak, which extend beyond
the posterior edge of the central pit.

Observations: The defective condition of the shells leaves many characters uncertain. Thus even in relatively
well-preserved specimens the edges of the shells are broken off and show neither the anterior course of the main ves-
sels nor the mouths of the secondary vessels where they enter the peripheral vascular canal.

The scars of the anterior lateral muscles of the small valve, which, owing to their position far forward, are also
for the most part broken off with the edge of the valve, were seen in three specimens.

In the typical form there seems to be a certain correlation between form, shell surface, and internal configuration,
but this correlation is not carried out very rigorously. The oval forms have the tip of the beak drawn somewhat farther
forward; the radial striation in them is for the most part less pronounced, while the concentric striation is stronger
and more roughly engraved. At the same time the shell surface is duller and lacks the strong varnish-like gloss which
is peculiar to the Oboli. To this external condition corresponds a less thickening of the posterior part of the shell,
and as a consequence a less pronounced development of all the characters connected with the thickening, such as
septa, ridges, central pit, etc. The internal marks of the last-named specimens are all developed to a recognizable
degree, but they lack relief. ;

Quite different is the case with the rounder forms. The shell surface is smoother and glossier, the concentric and
radial striation more alike, though the latter is always fainter, and at times is overpowered by the beginnings of an
irregular cracking of the surface, which is fully developed in O. apollinis ingricus. At the same time the internal con-
figuration shows a plasticity often bordering on the monstrous.

* * * * * * *

To O. apollinis in the narrower sense belong most of the forms described by earlier authors, in particular O. apol-
linis Eichwald [1829, p. 274, Pl. IV, figs. 5a-b], Ungula ovata Pander [1830, p. 59, Pl. III, fig. 23] (while the valve
figured by the same author in figs. 6a-b, Pl. XXVIII, belongs to a Schmidtia), O. ingricus von Leuchtenberg [1843,
p. 16, Pl. II, figs. 7-8], O. apollinis de ‘eenawiil [1845, p. 290, Pl. XIX, fig. 3c], Auwlonotreta polita Kutorga [1848, p.
278, Pl. VII, figs. 10a, a’, c?, d?, e?]; the other forms of Kutorga, so far as they may be recognized, belong to the varieties
of Eichwald’s species.

The specific name is derived from Apollo, the name Obolus apollinis signifying ‘‘a coin of
Apollo.”

FORMATION AND LOCALITY.¢—Upper Cambrian: (395f) Obolus conglomerate throughout the east Baltic region;
(836c) Obolus sandstone at Reval; (895) Obolus sandstone at Joa, near Jegelecht, 12 miles (19.3 km.) east of Reval;
(395b) Obolus sandstone at Ilgast; (9d) Obolus sandstone at Jaggowal, about 20 miles (32.2 km.) east-southeast of
Reval; (836b) Obolus sandstone on Odensholm Island, about 55 miles (88.6 km.) west of Reval; (836m) Obolus sand-
stone at Baltischport, about 30 miles (48 km.) west of Reval; (336t) Obolus sandstone at Wiems, 5 miles (8 km.) north-
northeast of Reval; and (336s) Obolus sandstone at Narwa; all in the Government of Esthonia, Russia.

(395z) Obolus sandstone at Jamburg on Louga (Luga) Rina (336a) Obolus sandstone at TPagiior (Putalova?) on
Tjora (Ischora) River; (386u) Obolus sandstone on the bank of Louga (Luga) River, southwest of St. Petersburg; (336k)
Obolus sandstone on Volkhof (Wolchow) River; (3361) Obolus sandstone on the bank of Sjass (Sias) River, near Lake
Ladoga; all in the Government of St. Petersburg, Russia.

(386r) Obolus sandstone in the entire region between Volkhof (Wolchow) and Sjass (Sias) rivers on the east and
Baltischport on the west, Governments of Novgorod, St. Petersburg, and Esthonia, Russia.

(811w) Drift bowlder of Obolus sandstone [Wiman, 1902, p. 68], Mariehamn, Aland Island, Finland, Russia.

(386c) Drift bowlder found near Lyck, East Prussia; mad (386d) drift ‘series found near Danzig p WER Prussia;
both in Germany.

(321, 321a—d, and 321o) Drift bowlders of Obolus sandstone, Nos. 1-23, and 25-29 [Wiman, 1902, p. 68], on Fanton
Island, parish of Bérstil, Province of Stockholm; (3901) Obolus conglomerate at Klittberget, in Dalarne, Province
of Kopparberg; (9e) Sandstone in the Obolus conglomerate at Boda, north of Rattvik, Dalarne; (311v [Wiman, 1902,

a The collections of the United States National Museum contain specimens of Obolus apollinis from Localities 9d, 9e, 336s, 395, 395b, and
895z. The other localities mentioned are taken from the references given in the synonymy. The authority for each locality cited will be
found in the list of localities, pp. 161-291.

384 CAMBRIAN BRACHIOPODA.

p. 68]) Drift bowlder of Obolus sandstone, Erskolmen Island, parish of Bérstil, southeast of Oresrund, Province
of Stockholm; and (390m) conglomerate overlying the ‘‘glauconite sand” at Horn, Oeland Island; all in Sweden.

Middle Cambrian: (368) Quartzitic sandstone in the Pepper Mountains, near Sandomierz, on the Vistula, Russian
Poland. {

OBOLUS APOLLINIS INGRICUS (Eichwald).

Obolus ingricus E1cHwap, 1829, Zoologia specialis, vol. 1, p. 274. (Described in Latin as a new species.)

Obolus ingricus ErcHwaup, 1843, Beitrage zur Kenntniss des russischen Reiches, Bd. 8, No. 2, pp. 140-141. (Char-
acterized and discussed in German.) :

Obolus apollinis Kichwald, ph VERNEUIL (in part), 1845, Géologie de la Russie d’Kurope, by Murchison, de Verneuil,
and de Keyserling, vol. 2, pt. 3, pp. 290-292 (not Pl. XIX, figs. 3a-d, which represent specimens of Obolus apol-
linis). (Described and discussed in French. The reference includes Obolus (Acritis) antiquissimus, Obolus
(Mickwitzella) siluricus, Obolus apollinis, and Obolus apollinis ingricus, Obolus apollinis being figured.)

Obolus ingricus Fichwald, von LeucaTEenBeERrG, 1843, Beschreibung einiger neuen Thierreste der Urwelt von Zarskoe-
Selo, p. 16, Pl. II, figs. 7and 8. (Not seen.)

Aulonotreta polita Kurore@a (in part), 1848, Verhandl. Russ.-kais. min. Gesell. St. Petersburg for 1847, pp. 279-282 (not
Pl. VII, figs. 10a-f, which represent specimens of Obolus apollinis.) (Described and discussed in German as a
new species. The text includes Obolus apollinis ingricus, Obolus ( Mickwitzella) siluricus, and Obolus apollinis,
the last species being figured.)

Obolus ingricus Ercuwap, 1860, Letheea rossica, ancienne période,vol. 1, sec. 2, pp. 926-927. (Described and discussed
in French.)

Obolus apollinis ingricus (Hichwald), Micxwrrz, 1896, Mém. Acad. imp. sci. St.-Pétersbourg, 8th ser., vol. 4, No. 2,
pp. 187-140, Pl. I, figs. 15-28. (Described and discussed in German.)

Mickwitz states that this shell has the same form as O. apollinis but that it is much larger
and the surface is more frequently and strongly marked by the concentric striz and lines of
growth; the central pit of the ventral valve is more pear-shaped. A full description is given of
the details of exterior form and interior markings of the valves so far as known to him.

FORMATION AND LOCALITY.2—Upper Cambrian: (336a) Obolus sandstone at Podolova (Putalova?) on Ijora (Ischora)
River; and (395z) Obolus sandstone at Jamburg on Louga (Luga) River; both in the Government of St. Petersburg, Russia.
(895) Obolus sandstone at Joa, near Jegelecht, 12 miles (19.3 km.) east of Reval; (395a) Obolws sandstone at Tihala,
near Jegelecht, 12 miles (19.3 km.) east of Reval; (336c) Obolus sandstone at Reval; (336t) Obolus sandstone at Wiems,

5 miles (8 km.) north-northeast of Reval; and (836s) Obolus sandstone at Narwa; allin the Government of Esthonia,
Russia.

OBOLUS APOLLINIS MAXIMUS Mickwitz.
Plate VII, figure 9; Plate XIV, figures 7, 7a.

Obolus apollinis maximus Micxwirz, 1896, Mém. Acad. imp. sci. St.-Pétersbourg, 8th ser., vol. 4, No. 2, pp. 140-143,
Pl. I, figs. 29-38. (Described and discussed in German as a new variety.)

Mickwitz states that this shell is very large, 21 mm. or more in diameter. Jt has more
regular, radial, and concentric striations than the variety ingricus and the surface is smoother.
The ventral valve near the beak is very thick. An elaborate description is given, accompanied
by full illustration.

FORMATION AND LOCALITY.—Upper Cambrian: (395) Obolus sandstone at Joa, near Jegelecht, 12 miles (19.3 km.)
east of Reval; and (395f [Mickwitz, 1896, p. 142]) Obolus conglomerate throughout the east Baltic region; both in the
Government of Esthonia, Russia.

(336j) Obolus sandstone at Staroja Ladoga, Government of Novgorod, Russia.

OBOLUS APOLLINIS QUENSTEDTI (Mickwitz).
Text figures 34A—B, page 374.

Ungula convexa PANDER, 1830, Beitrage zur Geognosie des russischen Reiches, pp. 59 and 163, Pl. XXVIII, figs. la—b.
(Characterized in German on p. 59; description of plate on p. 163.)

Ungula transversa PANDER (in part), 1830, idem, pp. 59 and 154, Pl. III, fig. 24 (mot Pl. XXVIII, figs. 7a—-b and
(?) 8a-b, which represent specimens of Obolus apollinis). (Characterized in German on p. 59; description of
plate on p. 154.)

a All of the localities mentioned are taken from the references given in'the synonymy. ‘The authority for each locality cited will be found
in the list of localities, pp. 161-291.

OBOLIDA. 385

Ungulites sp. QUENSTEDT, 1837, Archiv fiir Naturgeschichte, yon A. F. A. Wiegmann, Jahrg. 3, Bd. 1, pp. 143-145,
Pl. III, figs. 7 and 8. (Described and discussed in German.)

Obolus apollinis ZrrreL (in part) [not Ercuwaup], 1880, Handbuch der Palzontologie, Bd. 1, Abth. 1, p. 664, fig. 488d
(not figs. 488a-c, which represent Obolus apollinis). (No text reference. Fig. 488d is roughly copied from
Quenstedt, 1837, Pl. III, fig. 7.)

Obolus quenstedti Mrcxwirz, 1892, Mélanges géol. et paléontol. tirés du Bull. Acad. imp. sci. St.-Pétersbourg, vol. 1,
p- 62, fig. 1, and footnote on p. 60. (The description of the species is incorporated with that of the genus,
which isin German. The two specimens represented by fig. 1 were redrawn by Mickwitz, 1896, figs. 6A—B, pp.
79 and 117, and then copied in this monograph, figs. 34A and 34B, p. 374.)

Obolus quenstedti Mickwitz, Hatt and Crarxe, 1892, Eleventh Ann. Rept. State Geologist. New York for 1891, p. 243,
figs. 244and 245. (Generic reference questioned. Figs. 244 and 245 are copied from Mickwitz, 1892, fig. 1, p. 62.)

Obolus quenstedti Mickwitz, Hain and CrarKe, 1892, Forty-fifth Ann. Rept. New York State Museum for 1891, p. 559,
figs. 244 and 245. (Text and figures copied from preceding reference.)

Obolus quenstedti Mickwitz, Hatt and Crarxsn, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, p. 339, figs.
38 and 39. (Discusses species, questioning its reference to Obolus. Figs. 38 and 39 are copied from Mickwitz,
1892, fig. 1, p. 62.)

Obolus apollinis quenstedti Mickwi1rz, 1896, Mém. Acad. imp. sci. St.-Pétersbourg, 8th ser., vol. 4, No. 2, pp. 148-145,
figs. 6A—B, p.79, figs. 6A—B, p. 117, Pl. II, figs. 1-6. (Described and discussed in German; see below for trans-
lation of portions of the description. The text figures on p. 117, which are copied from those on p.79, are copied
in this monograph, figs. 34A and 34B, p. 374. Mickwitz’s figures, pp. 79 and 117, are drawn from the specimens
which he illustrated, 1892, fig. 1, p. 62, and which were copied by Hall and Clarke, 1892a, figs. 244 and 245,
p. 248; 1892b, figs. 244 and 245, p. 559; and 1892c, figs. 38 and 39, p. 339.)

Obolus quenstedti Mickwitz, Watcort, 1898, Proc. U.S. Nat. Mus., vol. 21, p. 385. (Translates part of the third para-
graph on p. 25 of Mickwitz’s paper, 1896, as below, and discusses the type species.)

Obolus quenstedti Mickwitz, MattHEw, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, p. 120. (Com-
pared, as the representative of Obolus, with ‘‘ Lingulella selwynt,”’ as the representative of Lingulelia.)

Of this shell Mickwitz [1896, p. 25] says:

A more accurate study of the greatly increased material has convinced me that O. quenstedti can not be maintained
as a species, since it is merely the terminal link of a series of variations; which, like var. maximus and ingricus, can be
traced back to O. apollinis. Thus the typical species remains O. apollinis Hichwald.

In describing O. apollinis quenstedti Mickwitz [1896, p. 143] says:

This variety is distinguished externally from the forms thus far described of O. apollinis by the circular outline of
its valves, their less pronounced arching (in the mean 0.159 for the large valve, and 0.183 for the small valve), and by
its smoother and more shining external shell surface, while by its size it is allied to the varieties ingricus and maximus
(in the mean 21.5mm.). The radial striz are more strongly developed and more uniformly distributed over the shell
surface than in other forms of Hichwald’s species, and they often exceed the concentric striz in distinctness.

The shells show two extceme forms connected by intermediate links. Those forms also show a corresponding
variation in the development of the internal characters. * * *

The internal shell surfaces of this variety (quenstedti) are most vigorously chiseled of all the forms of O. apollinis,
and although in all the details of their internal configuration they show merely the typical form, yet by the peculiar
development of the characters they present a picture differing from the other forms of Eichwald’s species. The
peculiarity in the development of the internal characters of this variety consists in this, that both the elevations and the
depressions are strongly developed, and in this way double the relief of the pattern. At the same time details become
apparent which in the other forms are distinguishable only by reflected light. Such is the longitudinal striation of
the posterior edge of the central pit.

The varietal name was given in honor of F. A. von Quenstedt.

ForMATION AND LOCALITY.—Upper Cambrian: (395 [ Wickwitz, 1896, p. 145]) Obolus sandstone at Joa; and (395a
[Mickwitz, 1896, p. 144]) Obolus sandstone at Tihala; both near Jegelecht, 12 miles (19.3 km.) east of Reval, Govern-
ment of Esthonia, Russia.

(395z [Mickwitz, 1896, p. 144]) Obolus sandstone at Jamburg, on Louga (Luga) River, Government of St. Peters-
burg, Russia.

OsoLus? BAvARICUS (Barrande).

Plate XV, figures 10, 10a.

Lingula bavarica BARRANDE, 1868, Faune silurienne des environs de Hof, en Baviere, p. 100, fig.62. (Described and
discussed in French as a new species. Fig. 62 is copied in this monograph, Pl. XV, fig. 10.)

Obolus ? palliatus BARRANDE (in part), 1868, idem, pp. 104-105, fig. 64 (not fig. 65, which represents the species palliatus).
(Described and discussed in French as a new species. Fig. 64 is copied in this monograph, Pl. XV, fig. 10a.)

Lingula bavarica BARRANDE, 1868, Neues Jahrb. fiir Mineralogie for 1868, pp. 690-691, unnumbered plate, fig. 62.
(Text and figure copied from Barrande, 1868a, p. 100, fig. 62.)

Obolus ? palliatus BARRANDE (in part), 1868, idem, p. 693, unnumbered plate, fie. 64 (not fig. 65, which represents
the species palliatus). (Text and figure copied from Barrande, 1868a, pp. 104-105, fig. 64.)

62667°—vo1 51, pr 1—12——25

386 CAMBRIAN BRACHIOPODA.

The author states [1868a, p. 100] that this shell can only be described by its external
appearance, and that this does not enable him definitely to identify it with Lingula or
one of the more recently distinguished genera Lingulella or Obolella. 'The shell is compressed.
The only portion preserved near the beak is about 0.5 mm. thick. Its external surface is
marked by somewhat irregularly spaced concentric striz, which are reproduced on the internal
east. Traces of longitudinal striz are shown on the fragment of shell preserved. The shell has
a length of 17 mm. and its greatest width is 16 mm. Comparison is made with Obolella plumbea
Salter, of the English rocks, and attention is called to the fact that the English species belongs
to the group of the lower Llandeilo, constituting a transition between the primordial and
second faunas like the schists of Hof.

FORMATION AND LOCALITY.—Passage beds between the Upper Cambrian and Ordovician: (303c [Barrande, 1868a,
p. 100]) suburbs of Hof, Bavaria, Germany.

L

Lingula belli Bruuines, 1859, Canadian Naturalist, Ist ser., vol. 4, pp. 431-432, figs. 7and 8. (Described and discussed
as a new species, as below. The specimens figured by Billings are redrawn in this monograph, Pl. XX XVIII,
figs. 3 and 3a, but it is impossible further to identify Billings’s figures with those in this monograph. )

Lingula bells Bruurnes, 1863, Geol. Survey Canada, Fifteenth Rept. Progress, figs. 47a-b, p. 124. (No text reference.
Figs. 47a-b are copied from figs. 7 and 8, respectively, of the preceding reference.)

OBOLUS BELLI (Billings).

Plate XX XVIII, figures 3, 3a—-b.

The original description by Billings follows:

Oval, apical angle about 75°, lateral margins somewhat straight or gently convex for two-thirds of the length, front
angles and anterior margins broadly rounded; length one-fourth or one-third greater than the width; greatest width at
about one-third the length or a little less from the front. Large specimens are one inch long and nine lines wide, but
the usual size is one-third smaller.

The form so far as regards convexity of the valves is somewhat variable. In general the specimens are strongly
convex, or very obtusely carinate from the beak to near the center of the shell, and have three flat slopes, one to each
of the lateral margins and one to the front. The most prominent point is a little above the middle, and the anterior
slope is always larger than the others. From this form, which is that of a very low three-sided pyramid, with all the
angles and edges broadly rounded, there is a series becoming more and more convex, until all trace of the anterior
slope is lost, while the two lateral slopes are only visible for a short distance below the beaks. By taking the extremes
several species might be made out of this one, but I am satisfied that they would not in the end be sustained.

The surface is sometimes nearly smooth, but usually it is marked by concentric undulations of growth. I have
not been able to detect any minute concentric striz between the larger undulations, and on only one of all the specimens
that I have seen are there any longitudinal striz, and these are only faintly indicated on the cast of the interior. The
specimens collected in the Chazy limestone in the neighborhood of Montreal are of a jet-black color and often exhibit
a polished shining surface, but those in the same rock in the valley of the Ottawa above Carillon are light brown.

The species is closely allied to L. antiqua (Hall) but is not longitudinally striated. In the Potsdam sandstone on
lots 21 and 22, in the 9th concession of the Township of Bastard, LZ. antigua occurs in vast abundance, and among
the specimens collected at that locality there are a great many which have almost exactly the same form as L. belli,
the only difference being the longitudinal striz.

I have also before me specimens from the Falls of St. Croix in Wisconsin, said to be L. prima of the Potsdam, and
these also have the depressed pyramidal elevation, but are in outline suborbicular or obscurely subpentagonal. The
elongated form sometimes referred to L. antiqua appears to me to be L. acwminata (Conrad), and differs from all the above
by being convex from the beak all along the median line to the front.

Billings [1859, p. 432] has indicated the resemblance of this species to “L. antiqua Hall” =
Tingulella (Lingulepis) acuminata (Conrad). In addition, I find traces of the heart-shaped
cavity of the ventral valve (Pl. XX XVIII, fig. 3a) so characteristic of Obolus and its sub-
genera. So far as known to me this is the latest species of Obolus known to occur in any
American geologic section.

The specific name was given in honor of Rev. A. Bell, of L’Original, near Montreal, Canada.

ForMATION AND LOCALITY.—Ordovician: Chazy formation at the following localities [Billings, 1859, p. 432]:
(319n) Island of Montreal; (3190) near L’Original; and (8319p) on Allumette Island; all in the St. Lawrence River

valley, Canada.
(892h [Billings, 1859, p. 432]) Limestone of the Chazy formation in the valley of Ottawa River, above Carillon,

Quebec, Canada.

OBOLIDA. 387

OBOLUS CHINENSIS (Walcott).

Plate XX XIX, figures 7, 7a-b.

Obolus (Lingulella) chinensis Waucort, 1905, Proc. U. 8. Nat. Mus., vol. 28, pp. 328-329. (Described and discussed
as below as a new species.)

General form broadly subovate, with the ventral valve broadly subacuminate and the dorsal
valve oval, with the posterolateral slopes somewhat straightened. There is some variation
in the proportions of width and length in different shells. Valves rather strongly convex for
so thin a shell, in this respect resembling species of Dicellomus. Surface marked by fine con-
centric striz and lines of growth and very fine undulating concentric lines; this outer surface
is usually a dull black and adheres to the matrix; when the outer layer is exfoliated the surface
is shiny black and marked by numerous radiating striz in addition to concentric striz; the
inner surface shows a few scattered puncte in addition to radiating and concentric striz out-
side the visceral area. ‘The shell is of medium thickness and formed of a thin outer layer and
several inner layers or lamelle that are slightly oblique to the outer layer; the lamellz are more
numerous and more oblique to the outer layer over the anterior and anterolateral portions
of the shell. The ventral valves average 3 mm. in length, with width varying from 2 mm. to
2.5mm. ‘The dorsal valve is slightly shorter than the ventral when the two valves have the
same width.

The interior of the ventral valve shows that the area is short and divided midway by
a narrow pedicle furrow that merges into the visceral area which extends forward about one-
third the length of the valve; on each side of the anterior central portion of the visceral area
there are two small trapezoidal areas within which the central scars and the middle and out-
side lateral muscle scars were attached; the small transmedian and anterolateral muscle scars
are situated close to the main vascular sinus opposite the anterior portion of the central visceral
area. A partial cast of the interior of the dorsal valve shows a rather wide visceral area with
the anterolateral scars about the center of the valve and the central scars about one-fourth
of the distance back from the center to the posterior margin. Of the impressions left by the
_ vascular system only the main vascular sinuses of the ventral valve have been seen. These
are situated about midway between the central visceral area and the margins of the valve.

Observations.—This species occurs abundantly in association with Acrotreta shantungensis
Walcott. It is closely related in form to Obolus prindlei (Walcott) of the upper Olenellus
zone of eastern New York, and belongs with a group of small shells that have a wide vertical
and geographic range, as is noted under the description of O. prindlei. With the data available
for comparison it differs from O. prindlei im its shorter cardinal area, and visceral area in the
dorsal valve. From Lingulella damesi (Walcott) it differs in being broader in proportion to
its length. :

ForRMATION AND LOCALITY.—Middle Cambrian: (C62) Harthy layer in the middle limestone of the Kiulung

group [Blackwelder, 1907a, pp. 37 and 40 (last list of fossils) and fig. 10 (base of bed 7), p. 38], 2.5 miles (4 km.) south
of Yenchuang, on the north-northeast spur of Hulushan, Sintai district, Shantung, China.

OBOLUS COMPLEXUS Barrande.

Plate XII, figures 3, 3a, 8, 8a.

Obolus? complerus BARRANDE, 1879, Systéme silurien du centre de la Bohéme, vol. 5, pt. 1, Pl. XCV, figs. mm: 1-2;
Pl. CXI, figs. vi: 1-2; Pl. CXIII, fig. v; and Pl. CLII, fig. um: 4. (No text reference. Pl. XII, figs. 3, 3a, 8,
and 8a, of this monograph are copied from Pl. CLII, fig. u:4A; Pl. CXIII, fig. v:A; Pl. XCV, figs. m1: 1A-B;
and Pl. XCV, fig. m1:2C, respectively.)

Obolella ?? complecus Barrande, Hatt and CiarKe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, p. 73, fig.
31. (Merely suggests change in generic reference. Fig. 31 is copied from Barrande, 1879b, Pl. CLII, fig. 1: 4A.)

Schmidtia?? complerus Barrande, Mickwrrz, 1896, Mém. Acad. imp. sci. St.-Pétersbourg, 8th ser., vol. 4, No. 2, pp.
19-20. (Generic relations discussed in German.)

Barrande [1879b] recognized the relations of this species to Obolus, although at the time
he did not have the results of Mickwitz’s studies to aid him. The latter [1896, p. 19] considers

388 CAMBRIAN BRACHIOPODA.

that Barrande’s figure [1879, Pl. CLI, fig. 1: 4] shows in the arrangement of the internal char-
acters a remarkable similarity to the large valve of Schmidtia. (This figure is represented in
Pl. XII, fig. 3, of this memoir.) A comparison with O. feistmanteli (Barrande) (Pl. XII, fig. 1d)
shows the relation of the interior markings in the two species. However, the figure of O. com-
plexus, which is an internal cast, has a poimted projection that mdicates the presence of the
transmedian and anterior lateral muscle scars much closer to the margin of the shell than the
other species of the genus. I think, however, that we are justified im referrig the species pro-
visionally to Obolus. The specimens figured by Barrande [1879b, Pl. XCV, figs. 11: 1-2] do not
appear to me to represent this species. The valve from Kruschna Hora (Pl. XII, fig. 3a)
probably represents a dorsal valve. All the characters known to me are shown by the figures.
Hall and Clarke [1892c, p. 73] considered that the species might be a genume Obolella.

FoRMATION AND LOCALITY.—Lower Ordovician: (303i) Etage d1, Kruschna Hora; (08h) Etage di, at Milinsky

Wrch, near Woleschna; and (308g) Etage dl, at Rabenberg; all [Barrande, 1879b, Pls. XCV and CX1] in Bohemia, ,

Austria-Hungary.
OBOoLUS CYANE (Billings).

Plate XX VII, figures 4, 4a—b.

)

Lingula cyane Bruu1nes, 1865, Geol. Survey Canada, Paleozoic Fossils, vol. 1, p. 216, figs. 200a-d, p. 215. (Described.
Billings’s type specimens are redrawn in this monograph, Pl. XX VII, figs. 4, 4a-b, but it is impossible further
to identify his figures with those in this monograph.)

Glossina cyane (Billings), SchucHERT, 1897, Bull. U. S. Geol. Survey No. 87, p. 224. (Merely changes generic
reference.)

General form ovate cuneate, broadly rounded at the front and sides, with the ventral
valve subacuminate and the dorsal valve broadly rounded at the beak; valves rather strongly
convex, especially the dorsal. Surface marked by concentric strie and slight undulations of
growth and by very fine radiating strie; when the outer surface is exfoliated the imner layers
or lamellz are marked by numerous radiating striz and concentric lines and undulations of
growth; the casts of the interior show essentially the same markings as the inner layers, except
over the visceral area, which is largely covered with fine papille corresponding to the minutely

pitted surface of the shell’s interior. The shell is thick and built up of a thin outer layer and _

numerous inner layers or lamelle arranged over the anterior portions of the shell obliquely to
the outer surface. Three ventral valves have an average length of 7 mm., with a width of
6 mm.; a dorsal valve 6 mm. in length is the same in width. The area of the ventral valve,
as shown in a cast, is divided at the center by a strong pedicle furrow and about halfway
between the pedicle furrow and the lateral margm by a sharp flexure line. The striz of
growth cross the area parallel with its base and show very clearly on the cast of the pedicle
furrow. The area forms a thin shelf between the pedicle groove and the lateral margins, the
undercut extending well back under the area. The area of the dorsal valve is relatively short
and narrow, scarcely showing when viewed from above.

The cast of the visceral cavity is strongly marked, but in none of the specimens are the
muscle scars shown. The central groove is shown in the cast by a rounded ridge, and the path
of advance of the trapezoidal area (c), in which the central, middle, and outside lateral muscle
scars occur, is beautifully shown by Plate XXXII, figure 4, the transverse ridges representing
- the lines of growth. The main vascular sinuses are fairly well shown in the same figure. There
are no traces of a median septum im the ventral valve, but this structure is clearly shown in
the casts of the dorsal valve, extending forward between the anterior lateral muscle scars.

The cast of the interior of the dorsal valve shows that m the adult the shell was thickened
over the visceral area and that the muscle scars were located on a comparatively elevated plat-
form. The position and form of the anterior lateral and central muscle scars and the direction
of the scar of the parietal band are fairly well shown by Plate XX VII, figure 4b, as is also the
umbonal sear (¢).

Observations.—This is a most interesting species on account of its preserving well into
Ordovician time the characteristics of well-marked forms of Lingulella from the Middle and Upper

aie anata

—

—

OBOLIDAL. a89

Cambrian. This may be seen by comparing with figures of Lingulella hayes: (Walcott) (Pl. XXV)
of the Middle Cambrian and Lingulella radula Matthew (Pl. XLV) of the Upper Cambrian.
Obolus cyane is of the same type as Lingulella iole (Billings) and is associated with it
in a horizon that appears to correspond with the upper portion of the Chazy and base of the
Trenton of the New York section. It differs in being more cuneate and less elongate.

ForMATION AND LOCALITY.—Lower Ordovician: (314d) Limestone of Division P [Billings, 1865a, p. 216] of the
“Quebec group,”’ 4 miles (6.4 km.) northeast of Portland Creek, Newfoundland.

OBOLUS DiIscoIDEUS (Hall and Whitfield).
iy :
Plate XVIII, figures 6, Ga-d.

Obolella discoida Haut and WurtrieLp, 1877, U.S. Geol. Expl. 40th Par., vol. 4, p: 205, Pl. I, figs. land 2. (Described.
One of Hall and Whitfield’s specimens, likely the one nepierantiedl by co 2, 1s nadanin ? in this monograph, Pl.
XVIII, fig. 6c; the specimen represented by fig. 1 is not figured in this raoornaemnrh, )

Obolella discoidea Hall and Whitfield, Watcorr, 1884, Mon. U.S. Geol. Survey, vol. 8, p. 14. (New localities mentioned.)

Obolella ? discoidea Hall and Whitfield, Waucott, 1886, Bull. U. S. Geol. Survey No. 30, p. 111. (Questions generic
reference.)

Obolella ? discoidea Hall and Whitfield, Hatt and Crarke, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, p. 69.
(Questions generic reference.)

Obolus (Lingulella) discoideus (Hall and Whitfield), Waxcorr, 1901, Proc. U. 8. Nat. Mus., vol. 23, p. 678. (Merely
changes generic reference.)

General form broad ovate to subcircular, with the ventral valve obtusely a and
the dorsal valve more broadly rounded posteriorly; both valves depressed convex, the umbo
of the ventral valve rising slightly toward the posterior margin. Surface of shell marked by
very fine, concentric undulating strize and lines of growth. When partly exfoliated the
inner lamellose layers are imbricated, their outer edges being irregular. The only traces of
the interiors observed show fine concentric striz of growth. Shell of medium thickness. It is
built up of a very thin outer layer and numerous inner layers arranged more or less obliquely
to the outer layer over the frontal portions. The largest valve has a length of 4.25 mm. with a
width of 4mm. No mteriors of either valve have been found among a large number of specimens.

Observations.—This pretty little shell is certainly not an Obolella. In shell structure and
form it is like Obolus.

FORMATION AND LocaLity.—Lower Ordovician: (185z) Limestones at the base of the Lower Ordovician [Walcott,
1908f, p. 191], in Blacksmith Fork Canyon, about 9 miles (14.4 km.) east of Hyrum, Cache County, Utah.

Upper Cambrian: (313j [Hall and Whitfield, 1877, p. 205) Limestone in the Eureka district; (66) Dunderberg shale
[Walcott, 1908f, p. 184], on the first ridge north of the Dunderberg mine; (62) limestone in the Dunderberg shale
[see Walcott, 1908f, p. 184], in canyon immediately north of Adams Hill; and (64) limestone near the Bullwhacker
mine; all in the Eureka district [Hague, 1892, Atlas], Eureka County, Nevada.

(8f) Limestones at summit of canyon, 10 miles (16.1 km.) south of Egan Canyon, east side of Egan Range, White
Pine County, Nevada. ;

(54e) About 200 feet (61 m.) above the Middle Cambrian and 1,025 feet (212.4 m.) below the top of the Upper
Cambrian, in limestones forming 3 of the St. Charles formation; and (54f) about 150 feet (45.7 m.) above the Middle
Cambrian and 1,075 feet (327.7 m.) below the top of the Upper Cambrian in the light-gray sandstone forming 4 of the
St. Charles formation; both in Blacksmith Fork Canyon [Walcott, 1908f, p. 193], about 10 miles (16.1 km.) east of
Hyrum, Cache County, Utah.

(56g) Limestone of the St. Charles formation [Walcott, 1908a, p. 6], in the valley of the stream which flows into
Mill Canyon from the west, about 6 miles (9.6 km.) west-southwest of Liberty, and 15 miles (24.2 km.) west of Mont-
pelier, Bear Lake County, Idaho.

(151) Limestone in point overlooking Churn Canyon, on the west side of the Bridger Range, Gallatin County,
‘Montana.

Middle Cambrian: (58) Shaly limestone in upper beds of Secret Canyon shale, east side of New York and Secret
canyons, Eureka district [Hague, 1892, Atlas], Eureka County, Nevada.

Specimens that are somewhat doubtfully referred to this species occur at the following
locality:

Upper Cambrian: (302r) About 1,000 feet (305 m.) above the quartzitic sandstones in the “‘ Yogo limestone (Devono-
Silurian)” of W. H. Emmons [1907, p. 34], near Princeton, Philipsburg quadrangle (U. S. Geol. Survey), Granite
County, Montana.

390 CAMBRIAN BRACHIOPODA.

OBOLUS DOLATUS (Sardeson).
Text figures 35A-C.
Lingula dolata Sarpeson, 1896, Bull. Minnesota Acad. Nat. Sci., vol. 4, p. 95, Pl. VI, fig. 12. (Described as a new
species. )
Only the exterior of the valves of this species is known. The outline of the valves is much
like that of Obolus matinalis (Hall) (Pl. VIII), and it does not differ more in this respect from

VY

FIGURE 35.—Obolus dolatus (Sardeson). A, Exterior of a large, crushed ventral valve, the type specimen.
B, Exterior of an elongate dorsal valve. C, Surface ridges on the front part of another dorsal valve, X14.
The specimens represented are all from Locality 339, near Stillwater, Minnesota, in beds which are reported by
Sardeson to be the Lower Ordovician Oneota dolomite.

that species than specimens of O. matinalis differ from each other. The chief specific distine-
tion is in the fine, narrow, sharp, slightly undulating, slightly inosculatmg concentric ridges;
the spaces between the ridges are about twice the width of the ridges. This surface is some-
what similar to that on the interspaces between the beaded idles of Obolus (Mickwitzella)
siluricus (Pl. XV, fig. 1c).

Tt may be that when specimens of the interior of the valves are found other differences
from O. matinalis will be noted. Obolus dolatus appears to be a Lower Ordovician Hejpeseiniaalive
of the widely distributed O. matinalis.

ForMATION AND LOCALITY.—Lower Ordovician: (339 [Sardeson, 1896, pp. 95 and 96]) from beds referred by Sardeson
to the Oneota dolomite, Stillwater, Washington County, Minnesota.

| OBOLUS EICHWALDI Mickwitz.

Obolus eichwaldi Mickwrrz, 1896, Mém. Acad. imp. sci. St.-Pétersbourg, 8th ser., vol. 4, No. 2, pp. 154-155, Pl. II,
figs. 15a-d. (Described and discussed in German as a new species.)

Of this species Mickwitz had only the posterior portion of a dorsal valve and some small
fragments. He states that the essential characteristics which distinguish it from O. triangu-
laris Mickwitz are the much finer, more regular, concentric striation and the somewhat irregu-
lar, undulating, radial ribs, which give the surface a somewhat wavy appearance through their
varying strength and occasional interruption. Mickwitz speaks of the circular form of the shell,
but the lines of growth on the fragment illustrated (PI. II, fig. 15a) indicate a somewhat trans-
verse shell. He also mentions peculiarities in the area of the dorsal valve. The student is
referred to the elaborate description of Mickwitz for further details.

Mickwitz states that O. eichwaldi is one of the rarest species of the Obolus sandstone.

The specific name was given in honor of C. E. von Hichwald.

FORMATION AND LOCALITY.—Upper Cambrian: (395 [Mickwitz, 1896, p. 155]) Obolus sandstone at Joa, near
Jegelecht, 12 miles (19.3 km.) east of Reval, Government of Esthonia, Russia.
OxsoLus ELEGANS Mickwitz.
Plate XV, figure 3.
Obolus elegans Mickwitz, 1896, Mém. Acad. imp. sci. St.-Pétersbourg, 8th ser., vol. 4, No. 2, pp. 157-158, Pl. 11, fig.

18. (Described and discussed in German as a new species.)

Only fragments were found of ‘“‘this most delicate species of the Obolus sandstone.”” The
shell appears to have been roundish and rather strongly convex, judging from one of the larger
fragments, which does not exceed 5 mm. in diameter.

——

ee

OBOLIDA. 391

The species is distinguished from all others of the Obolus sandstone by the rounded, narrow,
radiating ribs, which are increased by frequent interpolation from the umbo toward the front
margin. The surface is also marked by fine concentric striation. Nothing is known of the
internal characters.

Mickwitz states that this is one of the rarest of the known species of the Obolus sandstone.

In some collections made by Schmalensee I found nearly an entire specimen of the exterior
of the ventral valve; this is illustrated by Plate XV, figure 3. The surface of this shell is much
like that of Botsfordia celata (Hall) (Pl. LEX, fig. 1b).

FoRMATION AND LOCALITY.—Upper Cambrian: (395 [ Mickwitz, 1896, p. 158]) Obolus sandstone at Joa, near Jegelecht,
12 miles (19.8 km.) east of Reval; and (395b) Obolus sandstone at Ilgast; both in the Government of Hsthonia, Russia.

OBOLUS FEISTMANTELI (Barrande).
Plate XII, figures 1, la-f, 9, 9a.

Lingula festmanteli BARRANDE, 1879, Systéme silurien du centre de la Bohéme, vol. 5, Pl. CVI, figs. rv: 1-14;
Pl. CX, figs. vit: 1-4. (No text reference. Pl. XII, figs. 1, la, 1d, and 1f of this monograph are copied from
Barrande’s figures, Pl. CXVI, figs. tv: 7a, lla, 4a, and 12, respectively.)

General form rounded ovate to rounded subtriangular; ventral valve subacuminate, with
the dorsal valve rounded subacuminate; valves moderately and almost uniformly convex.
Surface of the shell marked by concentric undulations and strize of growth and, apparently,
fine radiating striz. The latter are shown only on one specimen, as the outer surface usually
adheres to the sandstone matrix, as in Plate XII, figure 1a. When the outer surface of the shell
is exfoliated, the surface of the inner layers is marked by numerous fine radiating striz (PI.
XU, figs. 1 and 1f), with more or less obscured concentric lines of growth. The radiating striz
appear to be distributed over the entire surface of the inner lamellz of the shell, but are strongest
on the inner, oblique layers of the anterior portion. In some instances the striz on the oblique
lamellz are somewhat irregular (Pl. XII, fig. 1e); the inner surface of the shell is marked by
small pits or puncte and by obscure concentric lines of -growth. The puncte are distributed
irregularly, being most prominent in the visceral portion. The general character is well shown
in Plate XII, figure 1f. The shell is formed of a thin outer layer, with numerous inner layers
or lamelle over the anterior and outer portions. These inner lamelle over the anterior portion
of the shell are oblique to the outer layer, and when the shell is partly exfoliated they appear
as imbricating layers (Pl. XII, figs. 1 and 1f). The layers or lamelle formed in the central
and posterior portions of the shell are relatively strong, and give considerable thickness to the
shell. When these are exfoliated and the oblique anterior lamelle are preserved, a shallow
but well-defined depressed rim extends all around the valves. This rim shows more or less dis-
tinctly in the cast of the interior of the shell (Pl. XII, figs. 1b and le). This species varies
somewhat in size and outline of the valves, but the variation shown is very slight in a large
series of specimens from the typical locality. A ventral valve 16 mm. in length has a width of
15 mm. A dorsal valve, represented in figure 1e, is slightly wider than long. Usually the
length and width of the dorsal valves is the same.

Casts of the interior of the ventral valve show a very clearly defined area. This is rather
short for so large a shell (Pl. XII, fig. 1b); it is divided midway by the cast of a narrow, rather
deep, pedicle groove; flexure lines have not been observed. The area extends well forward on
the cardinal slopes and is marked by strong strize of growth parallel to its front margin. One
of the casts indicates that the area formed a narrow shelf between the pedicle groove and the
lateral margins. The area of the dorsal valve is short and extends but a short distance out on
the cardinal slopes.

Casts of the visceral cavity are well shown for both valves (Pl. XII, figs. 1b and le). It
resembles that of Obolus matinalis (Hall) and O. apollinis Kichwald. The median septum has
not been seen in either valve. A narrow furrow extends down the center of the dorsal valve
between the central scars. A similar median depression is seen in the posterior portion of the
visceral cavity of the ventral valve.

The muscle scars of the ventral valve are not clearly defined. The umbonal scar is indi-
cated in one specimen (PI. XII, fig. 1b). It is divided, but no trace of a pedicle scar has been

392 CAMBRIAN BRACHIOPODA.

seen between the two. In the dorsal valve the umbonal scar is very close to the area and
extends some distance on each side of the median line. It is marked by fine striz subparallel
to the longitudinal axis of the shell. In one cast (Pl. XII, fig. 1b) the position of the trans-
median and anterior lateral scars is indicated; also the area in which the central, middle, and
outside lateral scars occur, but the scars are not differentiated. In the dorsal valve (Pl. XII,
fig. le) the central (h) and anterior lateral (j) scars are clearly defined also the position of the
transmedians (1). ‘

Portions of the markings left on the shell by the vascular system are well preserved in a
few specimens. The description is of the cast, or as the markings are shown on the thin inner
layer. The main sinuses are slightly rounded ridges that arch from the beak outward toward
the center and then inward well toward the anterior margin. Those of the ventral valve are
shown in Plate XII, figures 1b, 1c, and 1d, and the dorsal in figurele. Theinteriorlateral branches
in the ventral valve extend transversely from the main sinus nearly to the median line, except
toward the front, where they arch slightly backward (Pl. XII, fig. 1c); the exterior lateral
branches arch forward to the edge of the depressed rim, where they appear to pass into the small
interosculating canals that cross the rim to the outer margin, each canal dividing into three or
more branches; the peripheral vascular canal of Mickwitz [1896, p. 97] does not appear on any
of the specimens available for study, but this may be owing to our not having the inner surface
of the imner layer to examine.

The parietal scar is distinctly shown in front of the visceral cavity in both valves, but it
has not been traced outside of the main sinus, although the positions of the transmedian and
anterior lateral scars in the dorsal valve (Pl. XII, fig. 1b) indicate its approximate lateral
extension.

Observations —This large fine species is extensively illustrated by Barrande, but the material
at his command evidently did not satisfactorily show the muscle scars and vascular markings
of the interior of the valves. One figure of the ventral valve [1879b, pl. CVI, fig. rv: 4] indi-
cates the relative position of the main vascular canals and muscle scars (copied on Pl. XII,
fig. 1d, of this monograph), but it was not sufficiently clear to convince Mickwitz [1896, pp. 19-20]
that the species should be referred to Obolws, and Hall and Clarke [1892c, pp. 68-69] sug-
gested that it might be an Obolella. I found in the collections of the Museum of Comparative
Zoology at Cambridge a number of specimens showing casts of the interior of both valves. Of
these, three are figured in this monograph (Pl. XII, figs. 1b, 1c, le, 9, and 9a). Plate XII,
figure 1c, is of a specimen preserving the thin inner layer, on the exterior of which vascular
markings are beautifully preserved. Owing to the coarse character of the sandstone matrix,
the interior casts preserve only traces of the main sinuses. Figure le represents a similar
specimen in which the exterior lateral branches of the main sinus appear to subdivide at the
inner edge of the flattened rim and to continue across the rim to the outer edge, inosculating
and bifurcating im an irregular manner.

This is one of the most recent as well as the largest species of the genus. In form and the
arrangement of the vascular markings and muscle scars it may be compared with O. matinals
(Hall), which, however, is a much smaller species from the Middle Cambrian fauna. In outline,

size, and general arrangement of the muscle scars and visceral cavity the species may be com- _

pared with Obolus (Lingulobolus) affinis (Billings) (PI. XVI, figs. 1, 1a-e).
The specific name was given in honor of K. Feistmantel.

FORMATION AND LOCALITY.—Lower Ordovician : (303i [Barrande, 1879b, Pl. CX]) Sandstone of Etage d1, at Kruschna
Hora; and (303j [Barrande, 1879b, Pl. CVI]) Etage di, at Czerhowitz; both in Bohemia, Austria-Hungary.

OBOLUS FRAGILIS (Walcott).
Plate XXIII, figures 5, 5a-e. ‘
Obolus (Lingulella) fragilis Watcorr, 1898, Proc. U. S. Nat. Mus., vol. 21, p. 404. (Described and discussed essentially
as below as a new species.)
General form ovate, with the ventral valve subacuminate and dorsal valve broad ovate;
valves apparently moderately convex, as determined from the specimens more or less com-
pressed in the shale. Surface of shell marked by concentric lines of growth, and what appears

OBOLID. 393

to be an exceedingly fine papillose surface, which is apparently produced by the inosculation
of irregular, raised striz, as on the surface of Obolus (Westonia) ella (Hall and Whitfield) and
Lingulella ferruginea Salter and on a larger scale by Lingulella radula Matthew. When the
outer layer of the shell is exfoliated, very fine concentric and radiating striz occur on the surface
of the inner layers. The shell is thin and formed of an outer layer and one or more thin layers
or lamellee.

The average length of the ventral valve is about 5 mm.; width, 4mm. The dorsal valve
is a little shorter.

The rather long area of the ventral valve is divided midway by a strong pedicle groove
(Pl. XXIII, fig. 5). The area of the dorsal valve is clearly defined on casts of the interior; it
is about three-fifths the width of the valve and is arched forward at the center.

The casts of the interior of the valves show traces of the vascular markings, but nothing
very definite can be said of them.

Observations—This pretty little species is closely related to Lingulella ferruginea Salter,
with which it is associated in the shales of Manuels Brook. It is distinguished from the latter
by its broad form and thinner shell.

ForMATION AND LOCALITY.—Middle Cambrian: (la) Shales near the top of No. 6 of the Manuels Brook section; —
(1) shales of zone A of No. 7 of the Manuels Brook section; and (2) shales of zone B of No. 7 of the Manuels Brook sec-
tion; all on Manuels Brook (see Walcott, 1891b, p. 261, for position in section), Conception Bay, Newfoundland.

Oxsotus? inrLatTus Westergard.

Obolus ? inflatus WesTERGARD, 1909, Medd. fran Lunds Geol. Faltklubb, Ser. B, No. 4 (Aftryck ur K. Fysiografiska
Sallskapets Handl., N. F., Bd. 20), p. 76, Pl. V, fig. 25. (Described in Swedish as a new species; see below
for translation.) :

The original description by Westergard follows:

Interior of shell unknown, hence the generic identification is uncertain. The outer contour is almost elliptical,
being somewhat less broad than high. The thin shiny shell is posteriorly sharply convex and slopes from there to the
anterior margin. It has somewhat uneven, fine, but very distinct concentric striz and indistinct radial strie. Even
where the shell is exfoliated the radial striation is apparent.

FORMATION AND LOCALITY.—Passage beds between the Upper Cambrian and the Ordovician: (310x [Westergard,
1909, p. 76]) The uppermost limestone stratum, in beds equivalent to the Ceratopyge limestone, at Jerrestad, Province
of Malmohus, Sweden.

We OBOLUS ISMENE Walcott.

Plate XI, figures 3, 3a-b.

Obolus ismene Waucott, 1905, Proc. U. 8S. Nat. Mus., vol. 28, p. 325. (Characterized as below as a new species.)

This species is characterized by its elevated umbo, flattened posterior lateral margins, and
relatively thin shell.

All that is known of the exterior surface indicates that it was nearly smooth, marked only
by fine concentric striz of growth. The inner layers of the shell are beautifully marked by
fine concentric and radiating strie that give the surface a cancellated appearance. The shell
is built up of several layers or lamelle that become more oblique to the outer surface toward
the front.

FORMATION AND LOCALITY.—Upper Cambrian: (369) Sandstone in the Elvins formation, in the eastern limits of
the town of Flat River, St. Francois County, Missouri.

OBOLUS LAMBORNI (Meek).
Plate XXII, figures 2, 2a—n.

Lnngulella ? lamborni Mzrx, 1871, Proc. Acad. Nat. Sci. Philadelphia for 1871, vol. 23, pp. 185-187, fig.1. (Described
and discussed as a new species.)

Lingulella lamborni Meek, Kryus, 1894, Missouri Geol. Survey, vol. 5, pt. 2, pp. 38-39, Pl. XX XV, figs. 5a-d. (De-
scribed.)

General form broadly ovate, with the ventral valve obtusely acuminate and the dorsal
valve rather broadly oval; convexity apparently moderate, judging from specimens of the

394 CAMBRIAN BRACHIOPODA.

shells as they occur flattened out in the argillaceous shales. Surface of the shell marked by
concentric lines and striz of growth, and fine, slightly undulating striz in the interspaces, and
fine radiating strie; the mterior surface of the shell was strongly pitted or punctate, especially
in the posterior half (Pl. XXII, figs. 2, 2a, 2i, and 2]). The shell was relatively thin, and
formed of a thin outer layer and one or more inner layers or lamelle.

One of the larger ventral valves from Missouri has a length of 8.5 mm.; width, 7.5 mm.,
as it occurs flattened in the shale; an associated dorsal valve has a length and width of 8 mm.
The average size of the specimens from Tennessee is about 7 mm. for the ventral valve; a few
shells from Georgia are unusually large; one dorsal valve (Pl. XXII, fig. 21) has a length of
15 mm., width 12 mm., in the flattened shell.

As shown in the cast the area of the ventral valve is rather long, and is divided midway
by a strong pedicle furrow and marked midway between the furrow and the cardinal margins
by a narrow flexure line. The strize of growth cross the area parallel with its base and extend
over the cast of the pedicle furrow; they are very fine and closely grouped together on the
flexure line and on the lateral slopes. The area of the dorsal valve is rather long and extended
well out onto the cardinal slopes; it is marked in several specimens by unusually strong flexure
lines; the striz of growth cross it parallel to its base, curving sharply forward at the median
lime. From the condition of the casts of the cardinal area it is evident that it formed in both
valves a thin shelf, the undercut extending backward far under the area much as in Lingulella
ampla (Owen) (Pl. XXVIII), Lingulella acutangula (Roemer) (Pl. XVII), ete.

Casts of the interior of the ventral valve (Pl. XXII, fig. 2b) show in the visceral cavity (v)
traces of the heart-shaped pit (x). There are no traces of a median septum in the ventral
valve, but it is shown im the casts of a dorsal valve as a very narrow, clearly defined short
depression, extending from a point in front of the anterior lateral muscle ‘scars back between
the central muscle sears (Pl. XXII, fig. 2¢). =

Only the anterior lateral muscle scars are distinctly shown in the ventral valve. In one
specimen from Tennessee the trapezoidal area (c) is well preserved, but the central scars and
middle and outside laterals can not be differentiated (Pl. XXII, fig. 2f).

In the dorsal valve the central muscle scars (h), the anterior laterals (j), and the trans-
medians (i) are all discernible. The anterior laterals are small and situated near the center of
the shell, the centrals occurring some distance back and near the median septum, somewhat
as in Lingulella ampla (Owen) (Pl. XXVIII). Portions of the markings left on the interior of
the shell by the vascular system are shown on a cast of the interior. The main or trunk
sinuses are best shown in the ventral valve in specimens represented in Plate XXII, figures 2,
2a, 2b, and for the dorsal valve in figure 21. The parietal scar (ps) is distinctly shown in
front of the visceral area of the ventral valve (Pl. XXII, figs. 2 and 2b) and the dorsal valve
(figs. 2g and 2h); in both valves it extends out to the main sinuses (Pl. XXII, figs. 2 and 2h),
but it is not observed beyond them.

Observations.—This fine species is well characterized by the strongly pitted inner surface
and the elongate visceral area of the dorsal valve. The specimens from the type locality at
Mine Lamotte are usually more or less broken and crushed, but a few in the United States
National Museum show the form and outline and, more rarely, traces of the interior visceral
and muscle scar markings. The material from Tennessee is much more abundant and some-
what better preserved; a marked variation is shown in the size and number of the interior
pits or punctz, and a considerable range in the outline of the valves; the latter is mainly to
be attributed to distortion as the result of compression and a slight movement in the shale.
Most of the specimens from Tennessee are about the same size as those from Missouri, but a
number of larger shells were found about 50 feet lower in the section which are nearly double
the average size of the specimens from Missouri and Tennessee. J am not able to discover
any other differences that lead to considering them as a distinct species. The specimens are
flattened in the shale, which gives rise to more or less distortion. The most nearly related |
species is Obolus willist (Walcott) (Pl. XXIII) of the Middle Cambrian of Tennessee. The latter
differs in being shorter in proportion to its width, in the nearly transverse, obtuse posterior

OBOLIDA. 395

margin of the dorsal valve, and in the position of the central muscle scars. Specimens from the
limestone just above the shales at Mine Lamotte are moderately convex and more elongate
than those compressed in the shale. Some shells suggest the outline of Lingulella acutangula

(Pl. XVID).

ForRMATION AND LOCALITY.—Upper Cambrian: (7d) Shales in second cliff 0.125 mile (0.2 km.) west of Peak,
3 miles (4.8 km.) south of Clinton, Briceville quadrangle (U. 8. Geol. Survey), Anderson County; and (122a) shale
at the headwaters of Forgey Creek, northwestern part of the Greeneville quadrangle (U. 8S. Geol. Survey), Hawkins
County; both in Tennessee.

Middle Cambrian: (11j)¢ Shale and limestone in the basal part of the Bonneterre limestone, Mine Lamotte, Madison
County; (869f) limestone at Fredericktown, Madison County; (11m) drill cores of limestone at horizons 10 and 20
feet (3 and 6 m.) above the Lamotte sandstone, St. Francois County; and (369h) shale at Mine Lamotte, Madison
County; all in Missouri. c

(331) Rogersville shale 1 mile (1.6 km.) south of Fletcher, Greene County, Virginia.

(102) Rogersville shale just south of road, one-half mile (0.8 km.) southwest of Rogersville on the road to Melinda
Ferry [Keith, 1896a, areal geology sheet]; (103) second shale south of the ridge of sandstone in the Rome formation
(“Town Knobs”), on the road from Rogersville to Dodson Ford, near the line between the Morristown and Greene-
ville quadrangles (U. S. Geol. Survey); (121) Rogersville shale, road just east of Harlan Knob, 4 miles (6.4 km.)
northeast of Rogersville [ Keith, 1905, areal geology sheet]; (101b) Rogersville shale, just east of the schoolhouse, 3.5
miles (5.6 km.) southwest of Rogersville on the road to Melinda Ferry [Keith, 1896a, areal geology sheet]; and (124a)
shales (Nolichucky?) overlying the limestone which rests on the Rogersville shale, on Big Creek, southeast of Harlan
Knob, 4 miles (6.4 km.) northeast of Rogersville [ Keith, 1905, p. 4, and areal geology sheet]; all in Hawkins County,
‘Tennessee.

(140a) Shales 200 yards (182.9 m.) east of Thomas Mills, 5 miles (8 km.) north of Cave Spring [Hayes, 1902, his-
torical geology sheet], Floyd County, Georgia.

OBOLUS LAMBORNI MINIMUS (Walcott).

Plate X XV, figures 4, 4a—b.

Obolus (Lingulella) lamborni minimus Watcorr, 1898, Proc. U. S. Nat. Mus., vol. 21, p. 407. (Discussed as below as
a new variety.)

This variety in its ventral valve closely resembles the adult form of the ventral valve of
Obolus lamborni (Meek). The dorsal valve also has the same general form as most of the dorsal
valves of the species. In comparing, however, the young specimens of the same size with the
variety minimus the ventral valves appear to be more obtuse in the young of O. lamborni.

FoRMATION AND LOCALITY.—Middle Cambrian: (101 and 10la)® Rogersville shale, just above the road in the hill
west of the schoolhouse, 3.5 miles (5.6 km.) southwest of Rogersville on the road to Melinda Ferry | Keith, 1896a, areal
geology sheet|, Hawkins County; (103a) upper part of the second shale south of the ridge of sandstone in the Rome
formation (‘‘Town Knobs”), on the road from Rogersville to Dodson Ford, near the line between the Morristown and
Greeneville quadrangles (U. S. Geol. Survey), Hawkins County; (124) shales (Nolichucky?) overlying limestone
which rests on Rogersville shale, on Big Creek, southeast of Harlan Knob, 4 miles (6.4 km.) northeast of Rogersville
[Keith, 1905, p. 4, and areal geology sheet], Hawkins County; and (118) shales on the Tazewell road, 2 miles (3.2 km.)
north of Knoxville, Knox County; all in Tennessee.

OBOLUS LOPERI Walcott.
5 Plate IX, figures 4, 4a.

Obolus loperi Waucort, 1898, Proc. U. S. Nat. Mus., vol. 21, pp. 389-390. (Described and discussed as below as a
new species. ) ;

General form subsemicircular, with the ventral valve subacuminate and the dorsal valve
broad ovate to circular in outline. Some of the shells are more elongate than in what is consid-
ered to be the typical form. This type of variation is also observed in O. matinalis (Hall)
(Pl. VIII) and other species of the genus. Valves moderately convex as they occur in the
sandstone. Surface of the shell marked by concentric lines and fine strive of growth and very
narrow radiating undulations that are more or less interrupted by the concentric lines of growth.

aLocality 11j is given as the type locality, though the type specimens were collected from the Mine Lamotte locality long before the
collection to which this number was assigned. The two localities are believed to be the same.
+ 101a is the type locality.

396 CAMBRIAN BRACHIOPODA.

When the outer layer of the shell is exfoliated, the mner layers are seen to be marked by
numerous fine, rounded, radiating striz in addition to the concentric lines of growth; exceedingly
fine, irregular, interrupted striz give it in places a pitted appearance, while in a different light
it appears to be granulated, a feature of the surface that seems to be present on all of the inner
lamellee; sometimes the impression given is that the shell is minutely punctate.

The markings of the interior, so far as known, are rounded radiating strie. The shell is
rather thick and built up of a thin outer layer and several inner layers or lamellz that in the
anterior portions of the shell are rounded obliquely to the outer surface.

The largest shell in the collection is a somewhat imperfect dorsal valve 8 mm. in length.
A smaller valve, 6 mm. in length, has the same width. A ventral valve 6 mm. in length has the
portion about the beak broken away and is a little longer than wide.

The only trace of the interior of the valves is a partial cast of the dorsal valve. This shows
that the anterior lateral muscle scars were situated on the anterior portion of the valve about
one-third the length of the shell from the anterior margin.

Observations.—This species resembles in many respects O. matinalis (Hall), especially the
Texan form referred to that species. The material is poorly preserved, but it appears to be
clearly distinct from any described species. Its surface characters are like those of Obolus
prindlei (Walcott) (Pl. XX VII).

The species is named in recognition of the difficult and persevering work of Mr. S. Ward
Loper, curator of the museum of Middlebury College, who made a large collection of fossils
under the most adverse circumstances in the mountains of Colorado.

FORMATION AND LOCALITY.—Passage beds between the Upper Cambrian and the Ordovician: (335a) Reddish
sandstone on Cement Creek, 3 miles (4.8 km.) north of Hot Springs and 8 to 10 miles (12.8-16 km.) southeast of Crested
Butte, Ouray County, Colorado.

OBOLUS MCCONNELLI (Walcott).

Plate XXIII, figures 3, 3a (not 3b-d).@

Lingulella meconnelli Waxcorr, 1889, Proc. U. S. Nat. Mus., vol. 11, p. 441. (Described as a new species.)

Lingulella macconnelli Walcott, MartHEw, 1902, Trans. Roy. Soc. Canada, 2d ser., vol. 8, sec. 4, No. 3, p. 108. (Original
description copied and species discussed.)

Obolus meconnelli Watcort (in part), 1908, Canadian Alpine Journal, vol. 1, No. 2, p. 244, Pl. I, fig. 2 (mot fig. 2a, referred
in this monograph to Obolus septalis). (No text reference. Fig. 2 is copied in this monograph, Pl. XXIII,
fig. 3a.)

General form elongate ovate with the ventral valve subacuminate and rather broadly
rounded in front and obtusely rounded posteriorly. When the dorsal valve is crushed and
flattened in the shale it is broadly ovate. As far as can be determined from the somewhat
compressed shells the valves were moderately convex. Surface of the shell marked by concen-
tric lines of growth and fine, irregular striz that are more or less transverse and apparently
imbricating, giving a surface a little suggestive of Obolus (Westonia) aurora (Hall). When the
outer layer is exfoliated the surface of the inner layer is marked by concentric and radiating
strie. The interior surface is marked by rather strong radiating striz and scattered puncte.
The shell is thick for one of its size. It is formed of a thin outer layer, several thin inner
layers, and numerous lamelle in the anterior half of the valves. The only interior vascular
markings seen are those of the visceral cavity and main vascular sinuses of the ventral valve.

Observations.—Since the original description [Walcott, 1889c, p. 441] was written a few
specimens have been secured that add a little to the data for the description of the species.

The broad subtrigonal form represented in Plate XXIII, figure 3a, occurs on the same slab
of shaly limestone with the more elongate shell represented in figure 3. The latter is com-
pressed laterally, which makes it appear more elongate and also strengthens the radiating striz.

A small shell from Big Cottonwood Canyon, southeast of Salt Lake City, Utah, provisionally
referred to Lingulella helena (Walcott) (Pl. XXIV, fig. 3d), may prove to belong to this species.

a Figures 3b and 3c represent specimens of Obolus meconnelli pelias. Figure 3d represents a specimen of Obolus septalis.

ee oe

—— oe

OBOLIDL. 397

At most localities this species occurs within 200 feet of the base of the Middle Cambrian.
In the House Range section of Millard County, Utah, however, it has been found at about 1,500
feet above the Middle Cambrian, and at other localities a very closely allied form, which was
originally described as a species, ‘‘Obolus (Lingulella) pelias” [Walcott, 1905a, p. 330], occurs
in the middle portion of the Middle Cambrian and extends into the Upper Cambrian. This I
have now designated as the variety pelias. Another variety, decipiens, occurs in the Upper
Cambrian.

The variety pelias, as a whole, is slightly narrower in the dorsal valve and somewhat more
obtuse in the ventral valve. The variety decipiens is still shorter and broader in proportion as
compared with the typical Obolus meconnella.

This is one of the most persistent forms in the Middle Cambrian section of the Cordilleran
region, ranging, as it does, with its two varieties, from near the base of the Middle Cambrian
well up into the Upper Cambrian or through 4,500 feet of limestone. It also has a wide geo-
graphic distribution in the Cordilleran region, extending from British Columbia.to southeastern
California.

FORMATION AND LocALITY.—Middle Cambrian: (14s) About 2,300 feet (701 m.) above the Lower Cambrian and 2,700
feet (823 m.) below the Upper Cambrian, in the Ogygopsis zone of the Stephen formation [ Walcott, 1908f, p. 210), at the great
“fossil bed” on the northwest slope of Mount Stephen, above Field, on the Canadian Pacific Railway; (57£) about 2,200 feet
(670.6 m.) above the Lower Cambrian and 2,800 feet (853.4 m.) below the Upper Cambrian, in the limestones forming 1
of the Stephen formation [Walcott, 1908f, p. 209], about 0.5 mile (0.8 km.) east of the ‘‘ fossil bed ” on the northwest slope
of Mount Stephen, above Field, on the Canadian Pacific Railway; (58j) about 1,900 feet (579 m.) above the Lower
Cambrian and 3,100 feet (945 m.) below the Upper Cambrian, near the base of the limestone forming 2 of the Stephen
formation [Walcott, 1908c, p. 238 (7)], on the east side of Mount Stephen about 3,000 feet (914 m.) above the Cana-
dian Pacific Railway track 3 miles (4.8 km.) east of Field; and (58r) about 1,800 feet (548.6 m.) above the Lower
Cambrian and 3,200 feet (975.4 m.) below the Upper Cambrian, in the limestones forming 2 of the Stephen formation
[Walcott, 1908f, p. 211], in the amphitheater between Mounts Stephen and Dennis, above Field on the Canadian
Pacific Railway; allin British Columbia, Canada.

(35g) About 4,100 feet (1,250 m.) above the Lower Cambrian and 860 feet (262 m.) below the Upper Cambrian in
the shaly limestones in 2 of the Eldon limestone [Walcott, 1908f, p. 209 (‘‘Zingulella sp.’’)], at the north end of the
amphitheater northwest of the main ridge of Mount Bosworth; and (57c and 57k) about 2,500 feet (762 m.) above the
Lower Cambrian and 2,475 feet (754 m.) below the Upper Cambrian in the limestone forming 1 of the Stephen formation
[Walcott, 1908f, p. 209], on Mount Bosworth; both north of the Canadian Pacific Railway between Hector and Stephen,
on the Continental Divide between British Columbia and Alberta, Canada.

(58i and 58w) About 1,225 and 1,300 feet (373 and 396 m.), respectively, above the Lower Cambrian in the shales of
the Stephen formation [Walcott, 1908a, p. 3], northeast slope of Castle Mountain facing the amphitheater, north of the
Canadian Pacific Railway, Alberta.

(3j) Above the quartzitic sandstones in a shale corresponding in position to the upper part of shale No. 6 of the
Dearborn River section [Walcott,.1908f, p. 202], about 6 miles (9.6 km.) west-northwest of Scapegoat Mountain on the
Continental Divide between Bar Creek and the headwaters of the south fork of North Fork of Sun River, Coopers Lake
quadrangle (U. 8. Geol. Survey), Powell County, Montana.

(31¢) About 900 feet (274.3 m.) above the Brigham quartzite and 3,300 feet (1,005.8 m.) below the Upper Cambrian,
in the limestone forming 1b of the Ute limestone [Walcott, 1908f, p. 196]; and (54p) about 525 feet (160 m.) above the
Brigham quartzite and 3,665 feet (1,127.1 m.) below the Upper Cambrian in the shales forming 2f of the Ute limestone
[Walcott, 1908f, p. 197]; both in Blacksmith Fork Canyon about 10 miles (16.1 km.) east of Hyrum, Cache County, Utah.

(34n) Shales about 100 feet (30.5 m.) above the Tintic quartzite [G. O. Smith, 1900, p. 1], near the summit of the
ridge between Mammoth and Hureka; and (34s) about 1,700 feet (518 m.) above the Tintic quartzite in the Mammoth
limestone of G. O. Smith [1900, p. 1, and historical geology sheet], in the saddle above and a little east of the Centennial
Eureka mine, near the summit of the ridge between Mammoth and Hureka; both in the Tintic special quadrangle
(U.S. Geol. Survey), Juab County, Utah.

(30p) About 125 feet (38 m.) above the Cambrian quartzitic sandstones, on the north side of Ogden Canyon, about
1 mile (1.6 km.) above its mouth, east of Ogden, Weber County; and (31y) thin-bedded limestone about 125 feet
(88 m.) above the Cambrian quartzitic sandstones in the Wasatch Mountains, 1 mile (1.6 km.) northwest of Geneva
(Copenhagen), east of Brigham, Boxelder County; both in Utah.

(10y) About 2,900 feet (884 m.) above the Lower Cambrian and 1,500 feet (457.2 m.) below the Upper Cambrian in
the central part of the limestone forming la of the Marjum limestone [Walcott, 1908f, p. 179], about 1 mile (1.6 km.)
south-southwest of Marjum Pass; and (14v) shales of unknown stratigraphic horizon collected 1 mile (1.6 km.) south of
Rainbow Valley; both in the House Range [Walcott, 1908{, Pl. XIII], Millard County, Utah.

(8m) Limestone near the south end of the high ridge 4 miles (6.4 km.) northeast of Osceola; and (10w) shaly lime-
stones about 5 miles (8 km.) northeast of Osceola, on the east side of the Snake Range; both in White Pine County,
Nevada.

a This species is somewhat doubtfully identified from this locality.

398 CAMBRIAN BRACHIOPODA.

(14n) Limestone about 310 feet (94.5 m.) above the Lower Cambrian on the east side of the pass about 7 miles’
(11.2 km.) east of Resting (Freshwater) Springs, which is in the southwest corner of T. 21 N., R. 8 E., on Amargosa '
River, in the southeastern part of Inyo County, California. i

Middle? Cambrian: (32k) Limestones about 1,550 feet (472.4 m.) above the top of the quartzitic sandstones 2 miles
(3.2 km.) southeast of Muskrat Spring, on the northwest face of Grantsville Peak, Stansbury Range, Tooele County, Utah,

OBOLUS MCCONNELLI DECIPIENS N. var.

Plate XXIII, figures 4, 4a—b.

A form that appears to be a broad variety of Obolus mcconnelli (Walcott) occurs abun-
dantly in the arenaceous shales and interbedded limestone of the Upper Cambrian of the Silver
Peak Range, Esmeralda County, Nevada. Most of the material is badly preserved, and some
of the specimens afford fine illustrations of distortion of outline by compression. The variety
differs from the species in being uniformly broader and also in having more strongly marked -
concentric strive. It differs from the variety pelias in being of an average greater propor-
tional width.

FoRMATION AND LOCALITY.—Upper Cambrian: Emigrant formation [Turner, 1902, p. 265] at the following locali-
ties: (7v) shales 4.25 miles (6.8 km.) south-southeast of Emigrant Peak; (7x) limestone about 2.5 miles (4 km.) south-
east of Emigrant Pass; and (8r) shales about 8 miles (12.8 km.) southeast of Emigrant Peak; all in the Silver Peak
quadrangle (U. S. Geol. Survey), Esmeralda County, Nevada. ; :

Middle Cambrian: (7r) Calcareous shales 4 miles (6.4 km.) south-southeast of Emigrant Peak, Silver Peak quad-
rangle (U. S. Geol. Survey), Esmeralda County; and (8m) limestone near the south end of the high ridge 4 miles
(6.4 km.) northeast of Osceola, White Pine County; both in Nevada.

(14n) Limestone about 310 feet (94.5 m.) above the Lower Cambrian on the east side of the pass about 7 miles
(11.2 km.) east of Resting (Freshwater) Springs, which is in the southwest corner of T. 21 N., R.8 H., on Amargosa
River, in the southeastern part of Inyo County, California.

e OBOLUS MCCONNELLI PELIAS (Walcott).

Plate XXIII, figures 3b, 3c; Plate XX XIX, figures 5, 5a-c.

Obolus (Lingulella) pelias Watcotr, 1905, Proc. U. S. Nat. Mus., vol. 28, pp. 330-331. (Described and discussed as

a new species. )

This form was originally described [Walcott, 1905a, pp. 330-331] as a distinct species,
but, with the large collections obtained in 1906 from various horizons of the Middle Cambrian,
it is found to have close relations to Obolus meconnella of the lower portion of the Middle Cam-
brian. It ranges from about the central portion of the Middle Cambrian up into the Ordovician.

The variety differs from O. mcconnelli in being proportionally shorter and broader, and
from the variety decipiens, of the Upper Cambrian, in being, on the average, slightly narrower.

The outer surface of the shell is marked by clearly defined concentric lines that are slightly
irregular, and narrow, fine, radiating undulations or coste toward the frontal margins. When
unusually well preserved, the surface also shows very fine, irregular, concentric striz between
the concentric lines. The inner lamelle of the shell are marked by fine radiating striz and
the inner surface by more or less numerous puncte. Tor its size the shell may be considered
as relatively thin. F

FoRMATION AND LOCALITY.—Upper Cambrian: (54r) Drift pieces of limestone from the west slope of the Wasatch
Range; and (34q) shales about 3,800 feet (1,158.2 m.) above the Brigham quartzite [Walcott, 1908a, p. 8], in Wasatch
Canyon; both east of the Lakeview Ranch, about 5 miles (8 km.) north of Brigham, Boxelder County, Utah.

(32g) About 2,575 feet (784.9 m.) above the Cambrian quartzitic sandstones in a blue limestone about 2 miles
(3.2 km.) southeast of Muskrat Spring, on the northwest face of Grantsville Peak, Stansbury Range, Tooele County;
(33d) thin-bedded blue limestone at the base of the first high point southwest of the J. J. Thomas ranch, on the east
side of the Fish Spring Range, Juab County; and (30j) about 950 feet (289.6 m.) above the Middle Cambrian and
2,450 feet (746.8 m.) below the top of the Upper Cambrian near the base of the arenaceous shales and limestones form-
ing le of the Orr formation [ Walcott, 1908f, p. 176], on Orr Ridge, about 5 miles (8 km.) south of Marjum Pass, House
Range [Walcott, 1908f, Pl. XIII], Millard County; all in Utah.

(7s) Shale of the Emigrant formation [Turner, 1902, p. 265], 4 miles (6.4 km.) south-southeast of Emigrant Peak,
Silver Peak quadrangle (U.S. Geol. Survey), Esmeralda County, Nevada.

Middle Cambrian: (8j) About 575 feet (175.3 m.) above the unconformable base of the Cambrian in a shale which
corresponds in position to shale No. 4 of the Dearborn River section [Walcott, 1908f, p. 202], on the ridge between

Se

_OBOLID AL. 399

Gordon and Youngs creeks, about halfway between Gordon Mountain and Cardinal Peak, Ovando quadrangle (U. 8.
Geol. Survey), Powell County, Montana.

(15p) Limestones near the north end of the Fish Spring Range, Tooele County; and (15x) limestones near the
middle of the Fish Spring Range, near the line between Juab and Tooele counties; both in Utah.

(11n) About 3,000 feet (914.4 m.) above the Lower Cambrian and 1,400 feet (426.7 m.) below the Upper Cambrian
in the upper part of the limestone forming la of the Marjum limestone [Walcott, 1908f, p. 179], in the long cliff 2 miles
(3.2 km.) southeast of Marjum Pass; (110) about 2,750 feet (838.2 m.) above the Lower Cambrian and 1,650 feet (502.9
m.) below the Upper Cambrian, at the base of the limestone forming la of the Marjum limestone [Walcott, 1908f,
p. 179], about 4 miles (6.4 km.) southeast of Antelope Springs in the spur at the junction of the Deseret and Swasey
Spring roads; (1lq and 30g) about 2,350 feet (716.3 m.) above the Lower Cambrian and 2,050 feet (624.8 m.) below
the Upper Cambrian in the limestone forming ic of the Marjwm limestone [ Walcott, 1908f, p. 180], ridge east of Wheeler
Amphitheater; (8x and 3y) about 2,200 feet (670.6 m.) above the Lower Cambrian and 2,200 feet (670.6 m.) below
the Upper Cambrian in the limestones forming 1d of the Marjum limestone [Walcott, 1908f, p. 180], ridge east of
Wheeler Amphitheater; (8s and 8g) about 1,700 feet (518.2:m.) above the Lower Cambrian and 2,700 feet (823 m.)
below the Upper Cambrian in the shaly limestones and calcareous shales of the Wheeler formation [Walcott, 1908f,
p. 181], in the eastern part of Wheeler Amphitheater east of Antelope Springs; (8i) shales believed to be referable
to the lower portion of the Marjum limestone [Walcott, 1908f, p. 180], found about 0.5 mile (0.8 km.) east of Antelope
Springs; and (8k) shales 0.5 mile (0.8 km:) northwest of Tyler Springs, east slope of House Range east of Antelope Springs;
all in the House Range [ Walcott, 1908f, Pls. XIII and XV], Millard County, Utah.

(54h) About 3,140 feet (957.1 m.) above the Brigham quartzite and 1,050 feet (320 m.) below the Upper Cam-
brian in the limestones forming la of the Bloomington formation [Walcott, 1908f, p. 194], in Blacksmith Fork Canyon,
about 9 miles (14.4 km.) east of Hyrum, Cache County, Utah.

Middle? Cambrian: (34v) Limestone about 1,750 feet (533 m.) above the Cambrian quartzitic sandstones about
2 miles (3.2 km.) southeast of Muskrat Spring, on the northwest face of Grantsville Peak, Stansbury Range, Tooele
County, Utah.

OxsoLus M#RA (Hall and Whitfield).

Plate X, figures 2, 2a-e.

TIningulepis mera Hatt and WuitriELD, 1877, U. 8. Geol. Expl. 40th Par., vol. 4, p. 206, Pl. I,- figs. 5-7. (Described
and discussed as a new species. The specimens represented by figs. 6 and 5 are redrawn in this monograph,

Pl. X, figs. 2a and 2b, respectively.)

Lingulepis mxra Hall and Whitfield, Watcotr, 1884, Mon. U. 8. Geol. Survey, vol. 8, pp. 12-13. (New localities
mentioned. )
Lingulella? mxra (Hall and Whitfield), Hann and CrarKs, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1,

p- 61. (Suggests change in generic reference.)

Lingulella? mera (Hall and Whitfield), Wancorr, 1897, Am. Jour. Sci., 4th ser., vol. 3, p. 404. (Merely changes
generic reference.)

Obolus (Lingulella) mxra (Hall and Whitfield), Watcorr, 1899, Mon. U.S. Geol. Survey, vol. 32, pt. 2, p. 443. (Merely
changes generic reference.)

General form round ovate, with the ventral valve broadly subacuminate and the dorsal
valve obtusely rounded; valves rather strongly convex, the convexity mereasing gradually from
the margins to the umbonal portion of the shell, where it is greatest. Surface marked by con-
centric lines and fine striz of growth and very fine indistinct radiating strie that can be seen
only with a strong glass in a reflected light. When the outer layer of the shell is exfoliated the
surface is marked by numerous radiating striz, becoming coarser toward the front, where they
outline narrow, slightly raised ribs; this latter feature varies from simple radiating strie to the
appearance of narrow ribs; the interior surface has not been seen. The shell is formed of a
rather thin outer layer and numerous inner layers, which make a strong, thick shell; the inner
lamellze over the anterior portions of the shell are oblique to the outer layer and when the shell
is partly exfoliated appear as imbricating layers. A small ventral valve 10 mm. in length
has a width of 8mm. A larger associated dorsal valve has a length of 11 mm., width of 10 mm.

The only portion of the interior of the shell thus far discovered is an imperfect cast of a
portion of the area of a ventral valve (Pl. X, fig. 2).

Observations.—This species is most nearly related to O. matinalis (Hall) (PI. VIII). It
differs from that in being somewhat more elongate, although some exammles vary but little from
O. matinalis. The fact that it occurs in the Upper Cambrian near the base of the Ordovician
has more influence in leaving it as a distinct species than any differences which have been thus
far observed.

a11q is the type locality.

400 CAMBRIAN BRACHIOPODA.

The species is quite widely distributed. The type came from the thin-bedded limestones
in the Dunderberg shale, at the summit of the Cambrian in the Eureka district, Nevada. T. W.
Stanton found what appears to be the same species in sandy shales and sandstones at Glenwood
Springs, Colorado. A partly exfoliated, somewhat distorted ventral (?) valve from an Upper
Cambrian limestone one mile south-southwest of Highgate Falls, Vecmmont, appears to be
identical with O. mera.

ForMATION AND LOCALITY.—Passage beds between the Upper Cambrian and the Ordovician: (205) Siliceous
limestone on Roundtop Mountain, Eureka district [Hague, 1892, Atlas], Eureka County, Nevada.

Upper Cambrian: (313j [Hall and Whitfield, 1877, pp. 205 and 206]) Limestone in the Eureka district; and (61) lime-
stones in the Dunderberg shale [Walcott, 1908f, p. 184], a little south of the Hamburg mine; both in the Eureka
district [Hague, 1892, Atlas], Hureka County, Nevada. ;

(360h) Sandy shales about 200 feet (61 m.) above the base of the section at Glenwood Springs; and (360i) Sand-
stone about 100 feet (30.5 m.) above the base of the section at Glenwood Springs; both in Garfield County, Colorado.

Middle Cambrian: (58) shaly limestones in upper beds of Secret Canyon shale, east side of New Yorkand Secret
canyons, Eureka County, Nevada.

A specimen that is somewhat doubtfully referred to Obolus mzra occurs at the following
locality:

Upper Cambrian: (319q) Limestone 1 mile (1.6 km.) south-southwest of Highgate Falls, Franklin County,
Vermont. i

OBOLUS MATINALIS (Hall).

Plate VIII, figures 1, la—k.

Orbicula prima OwEN, 1852, Rept. Geol. Survey Wisconsin, Iowa, and Minnesota, p. 583, Pl. I 8, figs. 13 and 16-19.
(Described as a new species.)
Lingulepis pinnaformis Haut (in part) [not (OwEN)], 1863, Sixteenth Ann. Rept. New York State Cab. Nat. Hist., pp.
_ 129-130, Pl. VI, figs. 12 and 18 (not figs. 14-16, referred to Lingulella (Lingulepis) acuminata). (The specimens
represented by figs. 12, 13, and 15 are referred with doubt to ““Lingulepis pinnaformis” and the name matinalis
is proposed for them on p. 130 in the event of their proving distinct. The specimen represented by fig. 15 is a
dorsal valve of the true “‘ Lingulepis pinnaformis”—=Lingulella (Lingulepis) acuminata. See following reference.)
Lingulepis matinalis Hat, 1863, idem, p. 130, Pl. VI, figs. 12 and 13 (not fig. 15, referred to Lingulella (Lingulepis)
acuminata). (The specific name matinalis is proposed for the forms represented by figs. 12, 13, and 15 should
they prove distinct from those represented by figs. 14 and 16. See preceding reference.)

Lingulepis pinnaformis Haut (in part) [not (OwEn)], 1867, Trans. Albany Inst., vol. 5, p. 107, Pl. I, figs. 12 and 13 (not
figs. 14-16). (Copy of Hall, 1863, pp. 129-130, Pl. VI, figs. 12 and 13; see note following citation above.)
Lingulepis matinalis Har, 1867, ‘Glass p. 107, Pl. I, figs. 12 and 13 (not fig. 15). (Copy of Hall, 1863, Pl. VI, figs. 12

and 13; see note following citation above.)
Lingulella ? matinalis (Hall), Waucorr, 1897, Am. Jour. Sci., 4th ser., vol. 3, p. 404. (Merely changes generic reference.)
Obolus (Lingulella) matinalis (Hall), Watcorr, 1899, Mon. U. 8. Geol. Survey, vol. 32, pt. 2, p. 443. (Merely changes
generic reference.)

General form rounded ovate, with the ventral valve broadly subacuminate and the dorsal
valve obtusely rounded; valves rather strongly convex, convexity increasing gradually from
the margins to the central portion of the shell. Surface of the shell marked by concentric
lines and striz of growth and faint interrupted radiating striz; the finer concentric striz fill
in the interspaces between the lines of growth. When the outer layer of the shell is exfoliated,
the surface is marked by numerous fine, radiating striz (Pl. VIII, fig. 1a), and with more or less
obscure concentric lines of growth; the radiating strie are particularly strong over the anterior
portion of the inner oblique layers or lamellx of the shell. As far as can be determined from the
casts of the inner surface it was marked by concentric lines of growth and strong, radiating,
flattened strie (Pl. VIII, fig..le). The shell is formed of a thin outer layer and numerous
inner layers or lamelle over the anterior and outer portions; these inner lamellz over the anterior
portions of the shell are oblique to the outer layer, and when the shell is partly exfoliated they
appear as imbricating layers, as shown by Plate VIII, figure 1c; the layers of lamellz- over the
umbo and central portions are strong and give a considerable thickness to the shell. The
species vary somewhat in size and in the outline of the valves, as may be seen by comparing
the various figures. A ventral valve 11 mm. in length has a width of 11.5 mm.; another ventral

OBOLIDA. 401

valve 11.5 mm. in length has a width of 11 mm. A dorsal valve 9 mm. in length has a width
of 9 mm.; another dorsal valve 11 mm. in length has a width of 12 mm.

Casts of the interior of the ventral valve show a very clearly defined area of medium length
(Pl. VIII, fig. 1d); it is divided midway by the cast of a strong pedicle groove and about half-
way between the groove and the lateral margin by a distinct flexure line; strie of growth cross
the area parallel with its front margin, being flexed on the flexure line and arching over the cast
of the pedicle groove. None of the casts show whether the area formed a shelf between the
pedicle groove and the lateral margins, as in most species of the genus Lingulella. The area of
the dorsal valve is short and relatively narrow, extending about halfway out on the cardinal slopes.

The cast of the visceral cavity of the ventral valve is well shown by several specimens
(PI. VIII, figs. 1d and ie). It resembles that of Obolus apollinis quenstedti (Mickwitz) in having
the anterior margins extending almost directly outward from the center toward the impressions
of the main vascular sinuses. There are no traces of a median septum in the ventral valve; in
the dorsal valve it is shown in the cast as a very narrow depression and between and a little for-
ward of the central muscle scars (Pl. VIII, fig. ih). The thickening of the shell at the anterior
margin of the visceral cavity of the ventral valve is quite marked, as shown in Plate VIII,
figure 1f.

The muscle scars are well shown in one specimen of the ventral valve (Pl. VIII, fig. 1f).
The central (h), middle (k), and outside lateral (1) scars occur, but usually the scars can not be
differentiated. The anterior lateral (j) and transmedian (i) scars are also quite distinctly

“shown. In the dorsal valve (Pl. VIII, fig. 1h) the central (h) and anterior lateral (j) scars are
clearly defined, also the transmedian (i) scars. Of the markings left on the shell by the vascular
system the main vascular sinuses are usually well shown in the casts, and in one specimen of the
ventral valve both the inner and lateral branches are finely outlined (PI. VIII, fig. 1d).

The parietal scar (ps) is nearly transverse in front of the visceral area of the ventral valve;
it arches forward at the center and curves a little backward toward the main vascular sinuses.
Its course outside of the latter is partly shown by Plate VIII, figure 1d. In the dorsal valve its
course may be followed from the median line in front of the anterior lateral scars to the outward
curve of the trunk sinuses, beyond which it can not be traced with any degree of certainty.

Observations.—This species has not heretofore been well described or illustrated. Hall
[1863, p. 130] noticed that there were certain ovate shells associated with ‘‘Lingulepis pynna-
forms” which had a smooth, glossy surface, with fine concentric striz, and that when the outer
surface was removed it was very distinctly striated by fine, somewhat bifurcating striz. In
accordance with the system in vogue at that time he proposed, in event of the form proving
to be a distinct species, to have it called Lingulepis matinalis. A smaller shell occurs in asso-
ciation with Dicellomus politus (Hall) at Eau Claire, Wisconsin, that appears to be identical
with O. matinalis. It differs in having smaller central muscle scars in the dorsal valve, but, as
the variation in form and size of the muscle scars is often considerable in shells of the same
species, this is not considered sufficient for specific differentiation.

The Texas shells from Packsaddle Mountain (PI. VIII, figs. 1l-o) are smaller than the
typical Wisconsin forms, and are identified with Obolus tetonensis ninus (Pl. XI, figs. 1, la—g).
The specimens represented in Plate VIII, figures 1b, le, and 1h, are larger and more readily
identified with the species. A single ventral valve from the Bighorn Mountains is similar in
form to ventral valves from Texas. At La Crosse, Wisconsin, the shells are smaller and occur
about 200 feet below the base of the arenaceous limestone of the Ordovician.

This species appears to be distinct from any described form. It approaches most nearly
to O. mxra (Hall and Whitfield), differing from the latter in being slightly less elongate.

FORMATION AND LOCALITY.2—Lower Ordovician: (60a) Red siliceous limestone on west side of Trout Creek below
Bergen Park, 7 miles (11.2 km.) north-northwest of Manitou, El Paso County, Colorado.

Upper Cambrian: (302d) Limestone 200 yards (183 m.) north of the southwest corner of sec. 18, T. 28 N., R. 113 W.,
Uinta County, Wyoming.

@ Owen [1852, p. 583] gives the type locality as ‘‘falls of the St. Croix, Minnesota;”’ this might be compared with our localities 328h, 82s,-
and 328e, all in Wisconsin.

62667°—vou 51, pr 1—12——26

402 CAMBRIAN BRACHIOPODA.

(82b) “St. Croix sandstone’’ along the railroad track near Taylors Falls, Chisago County; (389d) ‘‘St. Croix sand-
stone’’ at Taylors Falls, Chisago County; (389f) ‘‘St. Croix sandstone’’ near Minneiska (Miniska) on Mississippi River
near the line between Wabasha and Winona counties; (97b) ‘‘St. Croix sandstone’’ below the green-sand bed and
25 feet (7.6m.) above St. Croix River at Franconia, Chisago County; and (339h [Hall, 1868, p. 130]) ‘‘St. Croix sand-
stone’’ at the mouth of Minneiska (Miniska) River, near the line between Wabasha and Winona counties; all m
Minnesota.

(828h) Silico-calcareous layers of Flb of Owen [1852, p. 583], at the falls of St. Croix River, Polk County; (100)
“St. Croix sandstone’’ near Menomonie, Dunn County; (184) ‘St. Croixsandstone’’ in the lowest beds exposed along the
banks of Red Cedar River, opposite Menomonie, Dunn County; (82a) ‘‘St. Croix sandstone’’ 25 feet (7.6 m.) above
the water level near the Knapp, Stoutand Company’s buildings, Menomonie, Dunn County; (82s) ‘‘St. Croixsandstone’’
on the bank of St. Croix River at St. Croix Falls, Polk County; (79, 79’, and 79b) ‘‘St. Croix sandstone”’ near Hudson,
St. Croix County; (83) ‘‘St. Croix sandstone’’ near Trempealeau, Trempealeau County; (78d) upper portion of “St.
Croix sandstone’’ exposed in the bluffs at La Crosse, La Crosse County; and (98 and 98x) “St. Croix sandstone’’
near Hau Claire, Hau Claire County; all in Wisconsin.

(9t) About 170 feet (52 m.) above the porphyry contact in the limestones of the Reagan sandstone, SE. } NE. }
sec. 2, T. 4 N., R. 13 W., 15 miles (24.2 km.) northwest of Fort Sill, Comanche County, Oklahoma.

(14e) Limestone in Bartlett Hollow, 2 miles (3.2 km.) southeast of the mouth of Falls Creek, Burnet quadrangle
(U. S. Geol. Survey), Lampasas County; (68 and 68z) limestone on Packsaddle Mountain, Llano County; (14b) lime-
stone on Cold Creek at north end of gorge opposite the north end of Sponge Mountain, 2 miles (3.2 km.) south of the
San Saba County line, in Llano County; (14c) upper part of the limestone exposed at Baldwin’s ranch, on Cold Creek,

2.5 miles (4 km.) south of the San Saba County line, in Llano County; (67, 67c, and 67z) sandstone on Tatur Hill, 7
miles (11.2 km.) northwest of Burnet, Burnet County; (14q) sandstone in Bartlett Hollow, 1.5 miles (2.4 km.) south-
east of the mouth of Falls Creek, Burnet quadrangle (U. S. Geol. Survey), Lampasas County; (14r) lower 50 feet of
sandstone on Colorado River, 3 miles (4.8 km.) south of the northeast corner of Llano County; and (71) limestone in
Cold Creek Canyon, Burnet County; all in Texas.

(92b) On Buffalo Creek, 2 miles (3.2 km.) southeast of Buffalo Mills, Rockbridge County, Virginia.

Middle Cambrian: (302) Limestone east of West Gallatin (collar) River, above Gallatin, Gallatin County,
Montana.

(170) Sandstone about 10 miles (16.1 km.) south-southeast of Bald Mountain, Bighorn Mountains, Wyoming.

(56f) Nounan limestone [Walcott, 1908a, p. 6], on a ridge north of the creek which flows into Mill Canyon from
the west, about 5 miles (8 km.) west-southwest of Liberty and 15 miles (24.2 km.) west of Montpelier, Bear Lake County,
Idaho.

(3e) Thin-bedded limestone less than 400 feet (121.9 m.) above the quartzitic sandstones of the Cambrian, at Ophir,
Oquiurh Range, Tooele County, Utah. S

(828e) ‘‘St. Croix sandstone’’ at St. Croix Falls, Polk County; and (83%) St. Croix sandstone at Trempealeau,
Trempealeau County; both in Wisconsin.

Specimens somewhat doubtfully eared to Obolus matinalis occur at the following localities:

Upper Cambrian: (11d) Arenaceous limestone about 2 miles (3.2 km.) north of Montana, in sec. 22, 7.35 N., R.1E.,
Tron County, Missouri.

Middle Cambrian: (319s) “St. Albans formation’’ at St. Albans, Franklin County, Vermont.

(1le) Thin-bedded limestones south-southwest of Potosi, Washington County, Missouri.

OBOLUS MATINALIS (Hall) ?

Plate VIII, figures 3, 3a.
(For synonymy of Obolus matinalis, see page 400.)
Obolus matinalis (Hall)?, Waucorr, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 325. (Mentioned as below.)

A form indistinguishable from this species occurs in China in a gray limestone of Upper
Cambrian age. Only the general form of partly exfoliated shells is known. _

FoRMATION AND LOCALITY.—Upper Cambrian: (C54) Lower part of Chaumitien limestone [Blackwelder, 1907a,
p. 42 (part of last list of fossils)], near top of limestone knoll, 0,66 mile (1.1 km.) west of Tsinan, Shantung, China.

OBOLUS MEMBRANACEUS Walcott.
Text figures 36A-B, page 403.

Obolus membranaceous Watcort, 1908, Smithsonian Misc. Coll., Vol. LIII, No. 3, p. 61, Pl. VII, fig. 11. (Character-
ized and discussed as below as a new species. Fig. 11 is copied as fig. 36A in this monograph.)

In size and outline this species is somewhat similar to Obolus feistmanteli (Barrande) (Pl. XII,
figs. 1, la-c), but in its very thin almost membranaceous shell it differs from that species and

i cares

OBOLIDA. 403

all other species of the genus known to me. Seven specimens were collected from a shaly compact
limestone, all as casts. Remnants of the corneous shell are
preserved, which show it to have been very thin, and the —
interior casts show that it did not retain any impressions
of the animal sufficiently strong to be impressed on the cast-
A short, rather narrow cardinal area occurs on both the
ventral and dorsal valves. Outer surface smooth, with a

few lines of growth. The largest ventral valve has a length A
o S FIGURE 36.—Obolus membranaceus Walcott. A,
of 17 mm. and a width of 22 mm. AN llegs omsuorieel clomsell Gein canal akin (aS Mai. ime, Gan Ie
valve has the same length and width, 15 mm. 53674a). B, Cast of dorsal valve (U. S. Nat. Mus.
The specific name was given because of the very thin © No: °8074P)._ Both natural size.

1 is i ll The specimens represented are from Locality 35g,
almost membranaceous shell. Eldon limestone on Mount Bosworth, British Co-

lumbia. Figure 36A is copied from Walcott [1908d,

FoRMATION AND LOCALITY.—Middle Cambrian (35g): About 4,100feet p) yy fig. 11]; it represents the type specimen

(1,250 m.) above the Lower Cambrian and 860 feet (262 m.) below the
Upper Cambrian in the shaly limestones in No. 2 of the Eldon limestone, at the north end of the amphitheater north-
west of the main ridge of Mount Bosworth, north of the Canadian Pacific Railway between Hector and Stephen, on
the Continental Divide, between British Columbia and Alberta, Canada.

Oxso.us? MENEGHINIT Walcott.

Plate XXX, figures 17, 17a.

Not Lingula petalon (Hicks MS.) Davinson, 1868, Geol. Mag. vol. 5, p. 308, Pl. XV, fig. 16. (Not taken up in this
monograph. )

Not Lingula petalon Davipson, 1871, British Fossil Brachiopoda, vol. 3, pt. 7, No. 4, p. 337, Pl. XLIX, fig. 30. (Not
taken up in this monograph.)

Lingula petalon BoRNEMANN [not Davinson], 1891, Nova Acta Acad. Czs. Leop.-Carol. Germanicze Naturze Curiosorum,
Bd. 56, No. 3, p. 438, Pl. XIX (XXXIV), figs. 12-14. (Described in German; see below for translation. Fig.
14a is copied in this monograph, Pl. XXX, fig. 17.)

Obolella sp. (?) BornEmManN, 1891, idem, p. 440, Pl. XIX (XXXIV), fig. 18. (Characterized in German. Fig. 18 is
copied in this monograph, Pl. XXX, fig. 17a.)

Obolus (?) meneghini Waucort, 1901, Proc. U. S. Nat. Mus., vol. 23, p. 684. (Bornemann’s description, 1891, p. 438,
translated, and species discussed as below as a new species.)

Bornemann says [1891, p. 438]:

Rounded triangular, frontal margin at times almost straight. Shells rather flat, their arching being greatest in
the middle. Concentric and rather coarse lines of growth. Size, 5-11 mm.

The specimen referred to ‘‘Obolella sp. (?)” by Bornemann [1891, p. 440] is from the slate
of Porto Canal Grande. It is not an Obolella and may be identical with the species from the
sandstones.

The shells referred to ‘‘Lingula petalon” [Bornemann, 1891, p. 438] suggest Obolus in form
and surface ornamentation and are tentatively referred to that genus and a specific name
given them in recognition of the work of Prof. Giuseppe Meneghini.

ForMATION AND LOCALITY.—Middle Cambrian: (354c) Yellow, friable sandstone at Punta Pintau (Canal Grande);
(354d) yellow friable sandstone at Gruguetta; and (354e) slate at Porto Canal Grande; all [Bornemann, 1891, pp. 438
and 440] in the island of Sardinia, Italy.

OxsoLus mMicKwitzi Walcott.

: Plate X, figures 1, la—k.

Obolus mickwitzi Watcott, 1898, Proc. U. S. Nat. Mus., vol. 21, pp. 386-387. (Described and discussed as below as

a new species. ) ‘

General form rounded ovate, with the ventral valve broadly subacuminate, and the dorsal
valve obtusely rounded; valves, as shown by the casts, moderately convex, which would give
a rather strongly convex shell, as fragments show that it was quite thick over the central
portions. Fragments of the shell showing the outer surface indicate that it was marked by
concentric lines and striz of growth; radiating striz may have been present; they are strongly
developed when the outer surface is exfoliated. The casts of a number of examples of the

404 CAMBRIAN BRACHIOPODA. '

interior of the valves show very strong concentric undulations and lines of growth, although
in some specimens these characters are scarcely perceptible. The fragments of the shell pre-
served show that it was formed of a thin outer layer, several inner layers or lamellz of varying
thickness, and numerous lamelle over the anterior and lateral portions of the shell that are
slightly oblique to the outer surface. A somewhat rounded ventral valve has a length of
9 mm., width 9 mm.; a dorsal valve 9 mm. long has a width of 8 mm.; a more elongate ventral
valve is 9 mm. in length and 8 mm. in width; an associated dorsal valve 7.5 mm. in length
has a width of 7 mm. d

Casts of the interior of the ventral valve show an area of medium length, divided midway
by the cast of a strong, rather broad pedicle furrow, and again a short distance each side of the
pedicle furrow by a narrow, sharp, flexure line; strie of growth cross the area of the pedicle
furrow parallel with the front margin. There is slight evidence in one of the casts that the area
formed a shelf between the pedicle groove and the lateral margin. The area of the dorsal valve
is of medium length and fairly well extended out onto the cardinal slopes (Pl. X, fig. 1d). The
cast of the visceral cavity of the ventral valve is. well shown by several specimens (PI. X, figs.
la, 1b, and 1c). It resembles that of Obolus matinalis Hall) and O. apollinis quenstedti (Mick-
witz) in the extension of the anterior margins almost directly outward from the center toward
the impression of the main vascular sinuses; one of the peculiarities of the species is the great
development of the area within the parietal scar (splanchnoceele); in some examples (Pl. X,
figs. la and 1b) it occupies all the central portions of the shell, extending to within a short
distance of the frontal margin. In others it is limited to the posterior half of the shell; the
same features occur in the dorsal valve (Pl. X, figs. 1d, le, and 1f). There are no traces of a
median septum in the ventral valve; in the dorsal valve it is shown in the cast as a very narrow
depression between and a little forward of the central muscle scars.

In the ventral valve the anterior lateral muscle scars are distinctly shown, also the trape-
zoidal area, in which the central, middle lateral, and outside lateral scars occur. In the dorsal
valve (Pl. X, figs. 1d and 1g) large central (h) and small anterior lateral (j) scars are clearly
defined, also the transmedian (i) scars. Of the markings left on the interior of the shell by
the vascular system, the trunk sinuses are usually strongly defined in the smaller shells, extend-
ing nearly to the anterior margin, and in the larger shells about three-fourths of the way over
the area to the frontal margin.

Owing to the condition of the casts of the interior, the parietal scar is usually not well
defined; in the ventral valve it appears to extend from where it arches forward at the center,
almost directly outward to the trunk sinuses, where it curves backward across the sinus and
outside of the anterior lateral muscle scars; in the dorsal valve it extends from over the median
line in front outward and backward around the side of the large central muscle scar, where it
curves outward across the trunk sinuses.

Observations.—Attention has been called to the relatively large size of the visceral cavity
(splanchnoceele) in both valves of the smaller shells. The range of variation i this respect
is so great that it might be accepted as indicating a distinct species if there were not shells
intermediate in size in which the splanchnoceele is also intermediate in proportional size.

Another marked character in the specimens is the very strong impressions in the cast of the
trunk sinuses and muscle scars and visceral markings. This species is somewhat more rounded
in outline than O. mzra (Hall and Whitfield) and O. matinalis (Hall), and it is very distinctly
marked by the muscle scars of the dorsal valve.

The specific name was given in honor of Dr. A. Mickwitz.

ForMATION AND LOCALITY.—Upper Cambrian: (79, 79’, and 79b)@ “‘St. Croix sandstone,’’ near Hudson; and (328j)
“St. Croix sandstone’’ on Willow River, near Hudson; both in St. Croix County, Wisconsin.

OxsoLus MINIMUS Walcott.
Plate XI, figures 8, 8a.

Obolus minimus Waxcort, 1905, Proc. U. S. Nat. Mus., vol. 28, pp. 325-326. (Described as below as a new species.)

This is a small shell of the general form of Obolus shansiensis Walcott. The ventral valve
is obtusely acuminate and the dorsal nearly circular; valves gently convex. Surface marked by

a 79 is the type locality.

OBOLIDA. 405

rather strong concentric lines of growth and numerous very fine concentric strie. The inner
layers of shell are shiny black and ornamented with numerous fine, radiating striz and concentric
lines. Shell built up of several thin layers or lamellz that form a thin shell over the umbonal
region that gradually thickens as the short, oblique lamellae become more numerous toward the
front and side margins. The three specimens in the collection average 3 mm. in transverse
diameter; the ventral is a little longer than the dorsal valve.

A partly exfoliated ventral valve shows a well-marked visceral area, extending forward
about one-third of the length of the shell; also narrow main vascular sinuses starting near the
apex and extending obliquely forward well into the valve, about midway between the median
line of the valve and the lateral margins. This neat little shell is distinguished by its nearly
circular outline, low convexity, and small size.

ForMATION AND LOcALITY.—Middle Cambrian: (€1) Lower shale member of the Kiulung group [Blackwelder,
1907a, pp. 37 and 40 (part of the 3d list of fossils), and fig. 10 (bed 4), p. 38], 2 miles (3.2 km.) south of Yenchuang,
Sintai district, Shantung, China.

rf OxsoLus? MINOR Barrande.

Plate XV, figure 6
Obolus ? minor BARRANDE, 1868, Faune silurienne des environs de Hof, en Bayiére, p. 105, fig. 68. (Described in
French as a new species. Fig. 68 is copied in this monograph, Pl. XV, fig. 6.)
Obolus ? minor BARRANDE, 1868, Neues Jahrb. fiir Mineralogie for 1868, p. 693, unnumbered plate, fig. 69. (Text
and figure copied from preceding reference.)
Of this species the author [1868a, p. 105] remarks:

We know only the impression figured. It differs from O.? palliatus Barrande by having a well-marked beak and
in being rather more elongate. The surface is ornamented by rather close concentric striz regularly spaced. Length
7mm., width 7 mm.

It is not improbable that this represents the ventral valve of O.? palliatus, but in the absence
of specimens for comparison it is left with the designation given by Barrande.

ForMATION AND LOCALITY.—Passage beds between the Upper Cambrian and the Ordovician: (308c [Barrande,
1868a, p. 105]) suburbs of Hof, Bavaria, Germany.

OxBoLus? mrRANDUS (Barrande).

Plate XII, figures 4, 4a.

Lingula? miranda BarRanpbe, 1879, Systéme silurien du centre de la Bohéme, vol. 5, Pl. OXI, figs. 1: 1-3. (No text
reference. Figs. 3A and la are copied in this monograph, Pl. X11, figs. 4 and 4a, respectively. )

In form this species is much like that of Obolus ancillus (Barrande) (Pl. XII). The traces
shown of the interior markings by figure 4a are similar to those of Obolus feistmanteli (Barrande)
(Pl. XI, fig. 1). The outer surface, as shown on the figure, recalls that of O. (Westonia) clla
(Hall and Whitfield) (Pl. XLVIT). With only the two illustrations given by Barrande, it
is impossible more than provisionally to refer the species to Obolus.

ForMATION AND LOCALITY.—Lower Ordovician: (303k [Barrande, 1879b, pl. CX1]) Etage dl at Hradischt, Bohe-
mia, Austria-Hungary.

OxsoLus? mMuRRAYI Billings.

Plate XV, figure 12.

Obolus ? murrayt BinuiNGs, 1865, Geol. Survey Canada, Paleozoic Fossils, vol. 1, p. 362. (Described as a new species;
see below for copy. The type specimen upon which Billings based his description, but which he did not
figure, is represented in this monograph, Pl. XV, fig. 12.)

The original description by Billings follows:

The specimen is very nearly circular, broad ovate, width a little greater than the length, uniformly and mod-
erately convex; the shell black and corneous and coyered with fine concentric striz. Length, 7 lines; width, about
8 lines. Of this species only a single valve was found. * * * It belongs probably to the Quebec group.

This appears to be a true Obolus, as far as can be determined from the exterior surface
of a single specimen. Its large size and strong concentric strie indicate that Billings’s refer-
ence to the ‘Quebec group” (Lower Ordovician) is probably correct.

406 CAMBRIAN BRACHIOPODA.

The specific name was given in honor of Alex. Murray, who discovered the specimen.

’ForMATION AND LOCALITY.—Lower Ordovician: (314g [Billings, 1865b, p. 362]) A loose piece of gray argillaceous
limestone at Maiden Arm, Hare Bay, on the east side of the northern point of Newfoundland.

OxsoLtus NAMOUNA Walcott.

Plate VIII, figures 2, 2a.
Obolus namouna Waucort, 1898, Proc. U. S. Nat. Mus., vol. 21, p. 390. (Discussed as below as a new species.)

This form is closely related to O. matinalis (Hall). It differs mainly in the internal char-
acter of the dorsal valve (Pl. VIII, fig. 2a). The area, in addition to the narrow area of
O. matinalis, extends its lines of growth nearly one-fifth the length of the shell. The visceral
area is shorter also than in O. matinalis, the central and anterior lateral scars being closer
together. Owing to the somewhat imperfect character of the ventral valve, no special points
of difference with the ventral valve of O. matinalis can be determined. It is associated on
the same slabs of sandstone with O. rhea Walcott.

ForRMATION AND LOCALITY.—Upper Cambrian: (98) “‘St. Croix sandstone” near Hau Claire, Hau Claire County,
Wisconsin.

Middle Cambrian: (84) ‘‘St. Croix sandstone” at Dresbach, opposite the mouth of Black River, Winona County,
Minnesota.

OsoLus NUNDINA Walcott.

Plate XI, figures 4, 4a.

Obolus nundina Waxcort, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 326. (Characterized and discussed as below as a
new species.)

This little shell differs from Obolus anceps Walcott, to which it appears to be most nearly
related, by its more nearly circular dorsal valve and its strong, concentrically ridged surface.
Its surface is formed by elevated, rounded, concentric ridges that are somewhat irregular.
Very fine concentric strie occur both on the ridges and on the interspaces between.

FORMATION AND LOCALITY.—Upper Cambrian: (61) Limestone in the Dunderberg shale [Walcott, 1908f, p. 184]
a little south of the Hamburg mine, Eureka district [Hague, 1892, Atlas], Eureka County, Nevada.

(14b) Limestone on Cold Creek at north end of gorge opposite the north end of Sponge Mountain, 2 miles (3.2 km.)
south of the San Saba County line, in Llano County, Texas.

Middle Cambrian: (58) Shaly limestones in the upper beds of Secret Canyon shale, east side of New York and
Secret canyons, Eureka district [Hague, 1892, Atlas], Eureka County, Nevada.

OBoLUS oBscuRUS Walcott.

Plate XI, figures 9, 9a-d.

Obolus obscurus Waucort, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 326. (Described and discussed essentially as in
the first two paragraphs below as a new species.)

A large dorsal valve of this species has a length of 9 mm., width 7 mm. The shell is
strong and marked on its inner layers by radiating and concentric striz; the outer surface has
numerous fine, elevated, slightly irregular, concentric striz that, with a strong lens, give it a
roughened appearance.

An interior of a dorsal valve shows a well-developed area, the greater portion of which |

is taken by the broad pedicle groove; a deep umbonal cavity with a narrow median septum
and obscure main vascular sinuses on the outer margins of the cavity. Outside the sinuses,
on the posterolateral slope, relatively large muscle scars are indicated.

Since the publication of the original description (the greater part of which is copied in
the two preceding paragraphs), better specimens referred to this species were received from
the Middle Cambrian of Shansi. These illustrate the form and convexity of the ventral valve
and show it to be similar to that of Obolus chinensis (Walcott). The concentric ridges are
more nearly perfect than those on the fragments associated with the specimens from Shantung.
The concentric striz or ridges are elevated, rounded, with sharp depressions between them;

OBOLIDA. 407

the ridges are little more than elevated strie at the aperture, becoming gradually coarser over
the central and anterior portions of the valve, where there are from five to seven ridges in a
distance of 1 mm.; toward the apex there are more than double the number in the same
distance.

Obolus obscurus has a larger and more rounded shell than O. chinensis and is also distin-
guished by the strong, concentrically striated surface, which resembles that of Micromitra
(Paterina) labradorica orientalis (Walcott), from which it differs in the form of the shell. It
differs from Obolus (Aeritis) antiquissimus (Eichwald) (Pl. XIII) in having the concentric striz
or ridges more regular and very rarely bifureating. Obolus (Acritis?) rugatus Walcott (PI.
XIII) has much stronger concentric ridges. The surface of O. nundina Walcott (Pl. X1) is
marked by irregularly spaced, rounded, concentric ridges, with rounded depressions between
them, instead of the V-shaped depressions and regularly spaced ridges of O. obscurus. Obolus
obscurus has a large strong shell of the general type of Obolus rhea Walcott (Pl. IX) of the
Middle and Upper (Commis of Wisconsin.

The material upon which this species was based [Walcott, 1905a, p. 326] was more or
less fragmentary, and the specific name was chosen because of the sThscunne relations of the
species.

FORMATION AND LOCALITY.—Middle Cambrian: (C63) Sandy shale near the base of the Kiulung growp [Blackwelder,
1907a, p. 37 (8d paragraph), and fig. 8a (bed 32), p. 29], 8.5 miles (5.6 km.) southwest of Yenchuang, Sintai district,
Shantung; and (C75) limestone near the base of the Kichou formation [Willis and Blackwelder, 1907, p. 143], 4.5
miles (7.2 km.) south of Wutaihien, Shansi; both in China.

OxsoLtus? PALLIatTUS Barrande.

Plate XV, figure 5.

Obolus ? palliatus BARRANDE (in part), 1868, Faune silurienne des environs de Hof, en Baviére, pp. 104-105, fig. 65
(not fig. 64, referred in this monograph to Obolus ? bavaricus). (Described and discussed in French as a new
species. Fig. 65 is copied in this monograph, Pl. XV, fig. 5.)

Obolus ? pallatus BARRANDE (in part), 1868, Neues Jahrb. ftir Mineralogie for 1868, p. 693, unnumbered plate, fig. 65
(not fig. 64, referred in this monograph to Obolus? bavaricus). (Text and figures copied from preceding reference.)
This shell is described from the external characters, and on this account was referred

provisionally to the genus Obolus. The author states that the form is transverse, beak obtuse,

and the convexity of the shell as preserved is greatest near the beak. The substance of the
shell appears to be like that of the associated Lingula. It is ornamented with fine concentric
striz, which tend to group themselves into bands on some specimens. On Barrande’s figure
radiating striz are shown, but are not mentioned in the text. Two specimens have a lene'th

of 13 mm., with their widths respectively 16 and 18 mm.

FORMATION AND LOCALITY.—Passage beds between the Upper Cambrian and the Ordovician: (303c [Barrande,
1868a, p. 105]) Suburbs of Hof, Bavaria, Germany.

OxBoLUS PANDEMIA Walcott.
)
- Plate IX, figures 3, 3a-d.

Obolus pandemia Waxcortr, 1898, Proc. U. 8. Nat. Mus., vol. 21, p. 388. (Characterized as below as a new species.)

The external form of this species is much like that of O. matinalis (Hall) (Pl. VIII). It
differs mainly in the characters of the imteriors of the valves. In the ventral valve the
central ridge is elevated so as to be the most pronounced feature. It not only fills up the
space usually occupied by the heart-shaped cavity, but rises much above the interior surface
of the shell. The trapezoidal areas (c) and the depressions occupied by the main vascular
sinuses are seen only with difficulty. The essential characters of the species are shown by
ficures on Plate IX.

FoRMATION AND LOCALITY.—Middle Cambrian: (10a) Sandy layers of the Rome formation, in west railroad cut
through Shooks Gap, in Bays Mountains, 10 miles (16.1 km.) southeast of Knoxville [Keith, 1895, areal geology sheet],
Knox County, Tennessee.

408 CAMBRIAN BRACHIOPODA.

OpBoLtus PANDERI Mickwitz.

Obolus panderi Micxwirz, 1896, Mém. Acad. imp. sci. St.-Pétersbourg, 8th ser., vol. 4, No. 2, pp. 149-151, Pl. II,
figs. 13a-d. (Described and discussed in German as a new species.)

According to Mickwitz, two fragments of this species have been found. These fragments
indicate that the shell was one of the largest species from the Obolus sandstone, being nearly
twice as large as the nearly related O. triangularis Mickwitz. He separates it from the latter
species on account of its size, ‘‘the pronounced pentagonal angular central groove, and the
remarkable combination of the corneous projection with the ridges of the main vascular canals,
and the somewhat less convexity of the ventral valve.”

Mickwitz states that this species is very rare. He gives a most detailed account of it,
to which the student is referred.

The specific name was given in honor of C. H. Pander.

FoRMATION AND LOCALITY.—Upper Cambrian: (395 [Mickwitz, 1896, p. 151]) Obolus sandstone at Joa, near Jege-
lecht, 12 miles (19.3 km.) east of Reval, Government of Esthonia, Russia.

OxsoLus PARVUS Walcott.

Text figures 37A-B.

Obolus parvus Watcort, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, pp. 61-62, Pl. VII, figs. 10 and 10a. (Described
and discussed as a new species. Figs. 10 and 10a are copied in this monograph as figs. 37A and 37B.)

Shell small, moderately convex, nearly semicircular in outline. Ventral valve a little
longer than wide and with the umbo curving gently to the minute marginal beak. Dorsal
valve a little wider than long and with apex marginal. Surface marked
by minute concentric strie of growth and an exceedingly fine network
of irregular lines that, with a lens magnifying 20 diameters, give it the
appearance of the surface of Lingulella (Lingulepis) longinervis (Mat-
thew) (Pl. XLIV, fig. 1p). Nothing is known of the interior of the valves.

FIGURE 37.—Obolus parvus Wal-
cott. A, exterior of a ventral
valve, the typespecimen (U.S.
Nat. Mus. Cat. No. 51400a). B,
exterior of a dorsal valve (U.S.
Nat. Mus. Cat. No. 51400b).

Figures 37A and 37B are copied
from Walcott [1908d, PI. VII, figs.
10 and 10a]. The specimens are
from Locality 35c, Lower Cam-
brian shale, on Mount Bosworth,
British Columbia.

The average diameter of the valves is from 1.5 to 2 mm., with the
ventral valve a little longer than wide and the dorsal valve slightly trans-
verse in outline.

In outline the shell approaches most nearly to-Obolus rotundatus
(Walcott) (Pl. XX, figs. 2, 2a-e) of the Middle and Upper Cambrian.
It differs in having a more rounded posterior outline in the ventral valve
and in its more transverse dorsal valve. Obolus pheres Walcott (Pl. XI,
figs. 6, 6a—b) of the Upper Cambrian is a very small shell, but it is
thicker and also more elongate than O. parvus. In form it resembles

Obolus minimus Walcott, from China (Pl. XI, figs. 8 and 8a), but it differs in having a less elon-
gate ventral valve and in its peculiar surface.

ForRMATION AND LOCALITY.—Lower Cambrian: (35c) Drift blocks of siliceous shale supposed to have come from the
Mount Whyte formation | Walcott, 1908f, p. 214], found on the south slope of Mount Bosworth, about 500 feet (152 m.)
northwest of the Canadian Pacific Railway track between Stephen and Hector, eastern British Columbia. ;

(35e) About 270 feet (82.3 m.) below the Middle Cambrian, in a greenish siliceous shale correlated with No. 3 of

the Mount Whyte formation on Mount Bosworth.[ Walcott, 1908f, p. 214], in the amphitheater between Popes Peak
and Mount Whyte, about 3 miles (4.8 km.) northwest of Lake Louise, southwest of Laggan, on the Canadian Pacific
Railway; and (58t) sandy shale about 150 feet (45.7 m.) below the Middle Cambrian, just below the big cliff on the
east shoulder of Castle Mountain, north of the Canadian Pacific Railway; both in Alberta, Canada.

Osotus PHERES Walcott.
Plate XI, figures 6, 6a-b.
Obolus pheres Waucort, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 328. (Characterized as below as a new species.)

This is one of the smallest of the Obolus species known to me, as it does not average 2 mm.
in diameter. It recalls at first sight Lingulella winona convexa (Walcott); but it differs in having
a thick lamellated shell and in bemg more rounded on the cardinal angles. The exterior

OBOLIDA. 409

surface is marked by concentric lines of erowth. The shell is built up of thin layers or
lamellee, those toward the front and sides being arranged obliquely to the surface, as in all of
the thick-shelled species of Obolus.

FORMATION AND LOcALITY.—Upper Cambrian: (10v) Shales in the “St. irom sandstone,’’ at Fox Glen, lyon
8 miles (12.8 km.) east of Baraboo, Baraboo quadrangle (U. 8. Geol. Survey), Sauk County, Wisconsin.

OBOLUS PRINDLEI (Walcott).

Plate XX VII, figures 3, 3a-e.

Obolus (Lingulella) prindlei Waucorr, 1898, Proc. U. 8S. Nat. Mus., vol. 21, p. 412. (Characterized and discussed
essentially as below as a new species.)

This species was at first considered to be identical with Lingulella granvillensis Walcott
(Pl. XXII). The study of a new lot of well-preserved specimens shows that it differs from
granvillensis in being less elongate, more ovate in outline, and marked upon the interior by a
very finely granulated surface; in the cast the papille and the fine depressions between them
appear to be arranged in transverse undulating lines. The transverse lines of growth on
the area of the ventral valve, as seen in the cast, are peculiar in having an abmicating or
lamellose-like arrangement. The areas of both salle are rather large fOr so small a species.
The average length of the ventral valve is 3.5 mm. to 4 mm., and the width is 3.25 mm. The
dorsal valve is a little shorter than the ventral.

Obolus prindlei belongs to a group of small shells (Pls. XXIX to XX XI) that is represented
by Lingulella ferruginea Salter, Obolus rotundatus (Walcott), Lingulella desiderata (Walcott),
Obolus chinensis (Walcott), Lingulella damesi (Walcott), and L. granvillensis Walcott. These
forms are among the earliest specimens of the genus and range through to the Ordovician fauna.
Lingulella granvillensis and Obolus prindlei occur in the upper limit of the Olenellus fauna of
eastern New York and western Vermont, and Obolus rotundatus and Lingulella manticula (White)
are found at the base of the Ordovician fauna.

The specific name is given in recognition of the effective work of Mr. L. M. Prindle, who, as
assistant to Prof. T. Nelson Dale, collected the first specimens of the species.

ForRMATION AND LOCALITY.—Lower Cambrian: (29) Limestone just above the bridge at the Stockport paper mill
on Kinderhook Creek, Columbia County; (35) limestones 1.5 miles (2.4 km.) north of Bald Mountain and 3.5 miles
(5.6 km.) north-northwest of Greenwich, Schuylerville quadrangle (U. S. Geol. Survey), Washington County; (45b)
limestone near the roadside about 1,200 feet (366 m.) east of Bristol’s house, near Low Hampton, about5 miles (8 km.) east-
northeast of Whitehall, Whitehall quadrangle (U.S: Geol. Survey), Washington County; (36b) limestones near school-
house No. 12, near Greenwich, Cambridge quadrangle (U.S. Geol. Survey), Washington County; (38a) limestone 2 miles
(8.2 km.) south of North Granville, on the road which turns south from the road running between that village and Truth-
ville, 4 miles (6.4 km.) west-northwest of Granville, Fort Ann quadrangle (U. 8. Geol. Survey), Washington County;
(72) limestone 5 miles (8 km.) east of Albany, Rensselaer County; (2b) limestone just north of Beman Park, in the
northeastern part of the city of Troy, Rensselaer County; (338k) limestone 2.5 miles (4 km.) southwest of Wynants-
kill, Rensselaer County; and (72a) limestone 1 mile (1.6 km.) southwest of Wynantskill, Rensselaer County; all in New
York.

Specimens that are compared with Obolus prindlci occur at the following locality:

Lower Cambrian: (25a) Limestone on the Hall (Donaldson’s) farm, 2 miles (3.2 km.) east of Swanton, Franklin
County, Vermont.
OBOLUS REFULGENS Matthew.

Plate IX, figures 2, 2a-d.

Obolus refulgens Matruew, 1892, Trans. Roy. Soc. Canada, vol. 9, sec. 4, No. 5, pp. 44-45, Pl. XII, figs. 6a-d.
(Described and discussed as a new Secces, The specimens represented by figs. 6d (ventral) and 6d (dorsal) are
redrawn in this monograph, Pl. IX, figs. 2 and 2a, respectively.)

Obolus ? refulgens Mickwirz, 1896, Mém. Acad. imp. sci. St.-Pétersbourg, 8th ser., vol. 4, No. 2, pp. 23-24. (Discussed
in German.)

Obolus refulgens MATTHEW, 1902, Trans. Roy. Soc. Canada, 2d ser., vol. 8, sec. 4, No. 3, p. 96, plate opposite p. 112,
figs. 1la—b. (Discussed.) ‘

Obolus (Monobolina) refulgens Marrnew, 1902, idem, p. 98. (Changes generic reference.)

410 CAMBRIAN BRACHIOPODA.

Monobolina refulgens Marrow, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, pp. 210-213, Pl. °
XVI, figs. 2a-b, Pl. XI, figs. 4a-b. (Copies the original description, Matthew, 1892, pp. 44-45, and describes
and discusses species. Pl. XI, figs. 4a-b, are copied from Matthew, 1892, Pl. XII, figs. 6d (ventral) and 6d
(dorsal); Pl. XVI, figs. 2a-b, are copied from Matthew, 1902b, plate opposite p. 112, figs. 1la-b.)

General form transversely ovate, the dorsal valve being slightly more rounded at the beak
than the ventral. Valves rather strongly convex, as»seen in a single specimen of an uncom-
pressed dorsal valve; most of the shells are flattened in the shale. Surface of shell marked by
concentric lines of growth and very fine, irregular striz that inosculate so as to produce a surface
much resembling that of Obolus fragilis (Walcott), Lingulella bellula (Walcott) , Obolus (Westonia)
ella (Hall and Whitfield), and other forms. The shell is not preserved on any of the specimens
in the collection. A ventral valve 6.25 millimeters in length has a width of 6.5 millimeters; a
larger dorsal valve 8 mm. in length has a width of 9 mm.

The cast of the interior of the valves shows a clearly defined rather strong area on each
valve. The only muscle scars clearly defined are the central scars of the dorsal valve.

Observations.—This species has the general form of Obolus mickwitzi Walcott (Pl. X) but
in the absence of good specimens detailed comparisons are of little value.

Matthew [1902b, p. 98] includes Obolus refulgens in the subgenus Monobolina Salter [1866b,
p- 334] on account of the close approximation of the ‘‘anterior adductor scars” of the dorsal
valve. ;

The illustrations by Davidson [1866, Pl. IV, figs. 20-27] of Monobolina plumbea (Salter)
indicate a platform of the type of that found in Elkama (Pl. LI, figs. 1, 1a, and 4b), and as
Monobolina plumbea is a Lower Ordovician species it may be that the latter is a descendant
of Elkania of the Cambrian. It is certainly not an Obolus.

FORMATION AND LOCALITY.—Upper Cambrian: (308 [ Matthew, 1892, p. 45]) Shales of Division C3ce of Matthew

[1892, p. 43], at Navy Island, St. John Harbor, New Brunswick.

(307 [Matthew, 1903, p. 213]) Shales of Division O3c of Matthew [1901a, p. 276], on McLeod Brook (=Barachois

River); and (372e [Matthew, 1903, p. 50]) shales on McMullins Brook, near McLeod Brook; both in Cape Breton,
Nova Scotia.

OxBoLUS RHEA Walcott.

Plate IX, figures 1, la-c.

Obolus rhea Watcort, 1898, Proc. U. S. Nat. Mus., vol. 21, pp. 387-388. (Described and discussed as below as a new
species. )

General form elongate ovate, with the ventral valve subacuminate, and the dorsal valve
elongate ovate in outline. Outer surface unknown, as all of the shells referred to this species
are more or less exfoliated; the surface of the inner layers shows numerous, rather broad, radi-
ating striz, and concentric lines of growth. The shell appears to have been formed of a thin
outer layer and several inner layers or lamelle arranged in the same manner as in Obolus
matinalis (Hall). A ventral valve 8 mm. in length has a width of 6 mm.; a shorter, broader
valve is 6.5 mm. long and 5.5 mm. wide. The two dorsal valves referred to this species are
larger than the ventral valves; one 9.25 mm. long has a width of 6.75 mm. and another 9.25
mm. long has a width of 7.25 mm.

Casts of the interior of the ventral valve show a rather short area that is not clearly
defined in any of the specimens. The cast of the pedicle groove is narrow and merges into the
cast of the groove extending forward to the visceral area; the area is also marked by flexure
lines and transverse striz of growth. The area of the dorsal valve is short in the one specimen
showing it. The cast of the visceral cavity on a ventral valve is clearly defined by a rather
narrow ridge that is expanded anteriorly in what may represent the heart-shaped cavity (v)
(Pl. IX, figs. 1, la). The parietal scar passes around in front of the visceral cavity and then
a little backward to the main vascular sinuses. No traces of a median septum have been
seen in either valve. :

The only traces of muscle scars observed are some irregular markings in the trapezoidal
area (c), in which the central, middle lateral, and outside lateral scars occur in the ventral
valve.

OBOLIDZ. 411

Observations.—This somewhat peculiar species is associated with Obolus namouna Walcott,
Dicellomus politus (Hall), and Obolus matinalis (Hall). The dorsal valves are clearly distinct
from any described form, approaching in some respects the elongate dorsal valve of Lingulella
(Lingulepis) acuminata (Conrad) (Pls. XL to XLII), differing, however, in being narrow and
more elongate; the ventral valves appear to be broader in proportion than the dorsal valve
and approach O. matinalis (Hall) (Pl. VIII) in outline but are more elongate.

FORMATION AND LOCALITY.—Upper Cambrian: (98) “‘St. Cie sandstone’’ at Eau Claire, Eau Claire County,
Wisconsin.
Middle Cambrian: (84) “St. Croix sandstone’’ at Dresbach, opposite the mouth of Black River, Winona County,
Minnesota.
OBOLUS? ROKITZANENSIS Barrande.

Plate XII, figure 6.
Obolus? rokitzanensis BARRANDE, 1879, Systéme silurien du centre de la Bohéme, vol. 5, Pl. CXXVI, fig. u: 5. (No

text reference. Tig. 5A is copied in this monograph, Pl. XII, fig. 6.)

Barrande gives only one illustration of this species. It recalls to mind those forms of
Obolus which preserve the radial striation on the interior surface. The configuration of the
visceral area also suggests that of the ventral valve of Obolus. The illustration is introduced
in order that the student may have before him a representation of all of the Obolus-like shells
known to me.- Figure 5 of Barrande [1879b, Pl. CX XVI] should be compared with the ventral
valve of Obolus complecus Barrande (Pl. XII, fig. 3, of this monograph), and for the Ted
striation with Plate XII, figure 3b.

The specific name is derived from Rokitzan, the type locality.

FoRMATION AND LOcALITY.—Lower Ordovician: (303b [Barrande, 1879b, Pl. CXXVI]) Etage d1 in the environs of
Rokitzan, Bohemia, Austria-Hungary.

OBOLUS ROTUNDATUS (Walcott).

Plate XX, figures 2, 2a-e.

Obolus (Lingulella) rotundatus Waucorr, 1898, Proc. U. S. Nat. Mus., vol. 21, p. 415. (Characterized as a new species;
see first paragraph below for copy.)

Obolus (Lingulella) desideratus Watcort, 1899, Mon. U.S. Geol. Survey, vol. 32, pt. 2, pp. 445-446, Pl. LX, fig. 2a
(not fig. 2, referred to Lingulella desiderata). (Described and discussed. The specimen represented by figure
2a is redrawn in this monograph, Pl. XX, fig. 2e.)

This small species is associated with Lingulella manticula (White). It differs from it in
its nearly circular form and more strongly pitted or punctate interior of the valves. A cast of
the interior of a dorsal valve shows a well-defined area, the cast of the median ridge and sep-
tum, and the central muscle scars. The ventral valve has a length of 3.5 mm., width 3 mm.;
dorsal valve, length 3 mm., width 3 mm.

The shells represented by Plate XX, figures 2 and 2a, are associated in the same hand
specimens of limestone with Lingulella manticula. The specimens represented by Plate XX,
figures 2b, 2c, and 2d, are from the Upper Cambrian beds of the Gallatin Valley, Montana,
but so far as can be determined from the material at hand for comparison they appear to
represent the same species.

FORMATION AND LOCALITY.—Lower Ordovician: (313d) Limestone at Schellbourne, Schell Creek Range, White
Pine County, Nevada.

Upper Cambrian: (160a) Sandstone west of Bear Creek, south of the Gallatin Valley, southwest of Bozeman,
Threeforks quadrangle (U. 8. Geol. Survey), Gallatin County, Montana.

(30q) Limestones about 2,300 feet (701 m.) above the Cambrian quartzites, on pipe line above limekiin, in
Ogden Canyon, 1 mile (1.6 km.) above its mouth, east of Ogden, Weber County; (384i) shales about 1 mile (1.6 km.)
northeast of Sand Pass, at the south end of the Fish Spring Range, Juab County; (33d) thin-bedded blue limestone
at the base of the first high point southwest of the J. J. Thomas ranch, on the east side of the Fish Spring Range, Juab
County; (380y) about 1,400 feet (426.7 m.) above the Middle Cambrian and 1,900 feet (579.1 m.) below the top of the
Upper Cambrian in the supposed metamorphosed equivalent of the shales forming 1b of the Orr formation [Walcott,
1998f, p. 176], above the granite contact on top of the ridge north of Notch Peak [Walcott, 1908f, Pls. XIII and XIV],
House Range, Millard County; and (84r) limestones 1.5 miles (2.4 km.) northwest of Wahwah Spring, about halfway
up the section to the north of the road at Cane Pass, Wahwah Mountains, Beaver County; all in Utah.

412 CAMBRIAN BRACHIOPODA.

(80) Limestone on the slope of the ridge where the range swings around to the northwest, 2 miles (3.2 km.) north
of Aurum, Schell Creek Range, White Pine County, Nevada.

(96) Limestone near the ford on the Cedartown road, 1.5 miles (2.4 km.) south of Rome, Floyd County, Georgia.

Middle Cambrian: (159) Limestones north of West Gallatin (Gallatin) River, Gallatin County, Montana.

(302b) Limestones near Crowfoot Ridge, Gallatin quadrangle (U.S. Geol. Survey), Yellowstone National Park,
Wyoming.

(34n) Shales about 100 feet (30.5 m.) above the Tintic quartzite [G. O. Smith, 1900, p. 1] near the summit of the
ridge between Mammoth and Eureka, Tintic special quadrangle (U. 8. Geol. Survey), Juab County, Utah.

(110) About 2,750 feet (838.2 m.) above the Lower Cambrian and 1,650 feet (502.9 m.) below the Upper Cambrian,
at the base of the limestone forming la of the Marjum limestone [Walcott, 1908f, p. 179], about 4 miles (6.4 km.)
southeast of Antelope Springs in the spur at the junction of the Deseret and Swasey Spring roads [Walcott, 1908f,
Pl. XIII], House Range, Millard County; (11x) about 2,200 feet (670.6 m.) above the Lower Cambrian and 2,200 feet
(670.6 m.) below the Upper Cambrian in the limestones forming 1d of the Marjum limestone [Walcott, 1908f, p. 180],
2.5 miles (4 km.) east of Antelope Springs, in ridge east of Wheeler Amphitheater [Walcott, 1908f, Pls. XIII and
XV], House Range, Millard County; all in Utah.

(7i) Limestone just west of the summit on the road east of Schellbourne, Schell Creek Range, White Pine County;
and (7j) limestones at the north end of the Quinn Canyon Range, 1 mile (1.6 km.) northwest of Italian Ranch foothills,
Nye County; both in Nevada.

Specimens that are somewhat doubtfully referred to this species occur at the following
locality : :

Upper Cambrian: (8p) Limestone haliway up the canyon east of McGill’s ranch, on the west side of the Schell
Creek Range, 14 miles (22.5 km.) northeast of Ely, White Pine County, Nevada.

OBOLUS SCHMALENSEEL (Walcott).

\
<i Plate XXX, figures 19, 19a-e.

Obolus (Lingulella) schmalensei Waxcotr, 1902, Proc. U.S. Nat. Mus., vol. 25, p. 605. (Characterized as below as a
new species.) :
This is the European representative of the American Obolus rotundatus (Walcott) (Pl. XX).
Its outline is slightly elongate to subcircular. When the shell is exfoliated, the cast indicates
that it was strong over the visceral area and thin toward the margins. The characteristic
features are well shown in the drawings.
The specific name is given in honor of Mr. Schmalensee, who collected the material for me.
ForMATION AND LOCALITY.—Middle Cambrian: (8w) Limestones of Paradoxides forchhammeri zone, at Andrarum,
20 miles (82 km.) northwest of Simrishamn, Province of Christianstad, Sweden.

(16h) Limestones of the Paradoxides forchhammeri zone, at Borregaard; and (16i) limestones of the Conocoryphe
exsulans zone, at Borregaard; both on Bornholm Island, Denmark.

Opsoius scumipti Mickwitz.

l

Obolus schmidti Micxwirz, 1896, Mém. Acad. imp. sci. St.-Pétersbourg, 8th ser., vol. 4, No. 2, pp. 152-154, Pl. II,
figs. 14a-c. (Described and discussed in German as a new species; see below for translation of the diagnosis.
Figs. 14a-c are copied in this monograph, Pl. XV, figs. 1la-c, respectively.)

Plate XV, figures lla-c.

The original description by Mickwitz follows:

Shells large, moderately arched; outline broad, egg-shaped; posterior borders of shell convex, not winged; beak
of the large shell scarcely prolonged. Surface of shell faintly polished. Growth lamellae marked by deep, regular,
roughly cut concentric furrows. Concentric strie fine, irregular, mingled. Radial striz perceptible as indistinct
traces. Area of large shell very small, peduncular groove pit-shaped. Thickening of posterior part of shell falling
away in two terraces to middle of shell. First terrace is steep at the broadest place of the heart-shaped groove, the
second: flat in front of the point of the latter. Posterior part of the thickening in the form of two club-shaped swell-
ings, which, separated at their posterior thick parts by a deep furrow in the prolongation of the peduncular groove,
pass over with their anterior ends into the swellings of the principal vessel furrows. Splanchnoccele of the large shell
strikingly shortened. Secondary, inwardly diverging traces of the vessels rectilinear, not ramified.

Observations.—Mickwitz states that, in addition to the concentric strize described and very

faint traces of radial striew, there are over the entire rather rough surface of the shell scattered,
irregular, flat grooves, whose radial position is unmistakable. He also calls attention to the

OBOLIDA. 413

peculiar interior configuration as described and shown in the illustrations. This species is stated
to be very rare and restricted to the Obolus sandstone.
The specific name was given in honor of Dr. Fr. Schmidt.

ForMATION AND LOCALITY.—Upper Cambrian: (395 [Mickwitz, 1896, p. 153]) Obolus sandstone at Joa, near Jege-
lecht, 12 miles (19.3 km.) east of Reval, Government of Esthonia, Russia.

ip OBoLus SELWYNI (Matthew).

Plate XXXVI, figures 1, la-h, 2, 2a-b; Plate XX XVII, figures 1, la-f.

Lingulella selwynt Matruew, 1895, Trans. Roy. Soc. Canada for 1895, 2d ser., vol. 1, sec. 4, No. 13, pp. 255-256, Pl.
I, figs. la-b. (Described and discussed as a new species. The specimen represented by fig. lb is redrawn in
this monograph, Pl. XX XVII, fig. Ic.)

Obolus zquiputers MartrHew, 1902, idem, 2d ser., vol. 8, sec. 4, No. 3, p. 94, Pl. I, figs. 4a-e. (Characterized. The
specimens represented by figures 4b and 4d are redrawn in this moneaaaaln, Pl. XXXVI, figs. 2 and 2a, re-
spectively.)

Lingulella selwyni MattHEw, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, pp. 62-63. (Notes on
orientation of shells.)

Lingulella selwyni MartHEw, 1903, idem, pp. 116-123, figures on p. 117, and Pl. VII, figs. la-c. (Described and dis-
cussed. The original reference, Matthew, 1895, pp. 255-256, is copied on pp. 120 and 121. The figures given
on p. 117 are diagrammatic drawings based on the specimens figured by Matthew, 1895, Pl. I, figs. la and 1b.
Matthew’s original drawings are, however, also copied in this reference, Matthew, 1903, Pl. VII, figs. 1a and
Ib. Pl. XX XVII, fig. Ic, of this monograph represents the specimen upon which Matthew based the diagram-
matic figures given in the right-hand figure on p. 117 and that given in Pl. VII, fig. 1b. Pl. XXXVI, figs. 1
and Ic, of this monograph represent the specimens on which Matthew based the diagrammatic figures given in
the left-hand figure on p. 117 and that given in Pl. VII,-figs. 1a and 1c.)

Obolus xquiputeis MattHEW, 1903, idem, p. 139, Pl. VIII, ‘Aza, 2a-e. (Described as a new species, but it is not the
first reference to the species; see sion. The menetnall reference gives the species as Obolus (Hoobolus) xquiputeis.
Figs. 2a-e are copied from Matthew, 1902, Pl. I, figs. 4a-e.)

General form subovate, broadly rounded in front. Ventral valve subacuminate and dorsal
valve broadly rounded at the beak. Surface of the shell marked by very fine, concentric striz
and lines of growth and indistinct very narrow undulations of the shell radiating from the beak.
When the thin exterior shell is exfoliated fine radiating lines are seen, and the inner surface
(outside of the visceral areas) shows radiating lines toward the anterior margin and irregularly
distributed puncte. The shell is of rather more than medium thickness. It is built up of a
thin outer layer and several inner layers, very much as the shell of Lingulella acutangula (Roemer).
(Pl. XVII, figs. 1m, In, and 1o).

A large, slightly distorted ventral valve has a length of 14 mm.; width, 11mm. _ The origi-
nal proportion of length and width of this specimen was probably 14 to 12. The dorsal valve
was probably of equal length and width.

The area of the ventral valve is more or less distorted in all the specimens; its character is
best shown in Plate XX XVII, figure 1b; and the area of the dorsal valve in Plate XXXVII,
figure le. The pedicle furrow is strong and well defined (Pl. XX XVII, fig. 1b).

The cast of the interior of the ventral valve shows the visceral cavity and the heart-shaped
pit (x) (Pl. XXXVI, fig. 1d) so characteristic of Obolus. There are no traces of a median septum
in the ventral valve; mm the dorsal valve it is a sharp, narrow ridge (Pl. XXXVI, figs. le-g).

The muscle scars of the valves are well shown in casts of the interior. The umbonal scar of
the dorsal valve is elongate (Pl. XX XVII, figs. le and 1f, and Pl. XXXVI, fig. le). I have not
observed it in the ventral valve. The scars of the central muscles (h) are distinct in the dorsal
valve (Pl. XX XVII, fig. 1c), but on the ventral valve they are merged with the middle laterals
in the trapezoidal area (c) (fig. 1d). The outside laterals (1) are preserved in interiors of the
ventral valve (Pl. XXXVI, figs. 1d and le) and the dorsal valve (Pl. XXXVI, fig. le). The
middle laterals (k) are shown on the dorsal valve (Pl. XXXVI, fig. le), but have not been seen
on the ventral valve. The anterior laterals are shown for the dorsal valve at (j) (fig. 1c). The
_ transmedian scars (i) are preserved on casts of the dorsal valve (Pl. XXXVII, figs. 1c, le,
and 1f) and the ventral valve (Pl. XX XVI, fig. 1a).

414 CAMBRIAN BRACHIOPODA.

The parietal scar is clearly shown in front of the visceral cavity of the ventral valve, between
the main vascular sinuses (ps) (Pl. XX XVII, fig. 1d), but it has not been traced beyond the
main sinus. On the dorsal valve its course may te followed from the median line in front of the
anterior lateral muscle scars (j), back beyond the central scars (h), to a poimt where it curves
outward (ps) (Pl. XX XVII, fig. 1c).

Observations. iene sent me the types of this species for study and illustration. From
the first lot sent in 1900 the figures on Plate XX XVII were made. A second lot sent in 1903
gave the fine illustrations on Plate XXXVI. The two figures in his paper (1895b, Pl. I) of the
Tanita and dorsal valve are essentially diagrammatic, combining as they do the chaminertese seen
in a number of specimens. I have illustrated several of the specimens that appear to me to
give a fair presentation of the characters.

As stated by Matthew [1895b, p. 256] the plan of the muscular scars of this species is very
nearly that of Obolus apollinis quenstedti (Mickwitz). It may also be compared with the arrange-
ment of the scars of Lingulella acutangula (Roemer). Further reference to O. selwynt will i
found under the discussion of Obolus and Lingulella (p. 377). In a general way comparison
may be made between Obolus selwyni and Lingulella acutangula; specifically there are strong
variations between them.

Obolus zquiputers Matthew appears to be in all respects identical with O. selwyni. To
illustrate the identity of the two species photographs were made of the types of O. zquiputeis
(Pl. XXXVI, figs. 2, 2a-b). The dorsal interiors have both been distorted. In figure 2b the
distortion is from transverse compression; in figure 2c from longitudinal gennpeassion. The
specimen represented by the latter is associated with Obolus selwynv. The specimens represented
by Plate XXXVI, figures 2a and 2b, are casts in a matrix that preserves the interiors very
clearly. Plate XXXVI, figure 2G, rnd all other illustrated specimens of this species, are from
a matrix in which the shell j is compressed so as to obscure the interior markings.

The calcareous sandstones in which this species occurs were referred to the Ordovician by
Matthew [1895b, p. 255], but in his review of the Cape Breton Cambrian faunas [1903, p. 123]
he assigns it to Division E2a? of his lower Etcheminian.

The specific name was given in honor of Dr. A. R. C. Selwyn.

FoRMATION AND LOcALITY.—Middle Cambrian: (307d [Matthew, 1903, p. 123]) Sandy limestone of Division

E2a? of Matthew’s [1903, p. 19] Etcheminian, on Young (McFees) Point near George River Station, on the
Intercolonial Railway, eastern Cape Breton, Nova Scotia.

OBOLUS SEPTALIS (Walcott).

Plate XXIII, figure 3d; Plate XXXIV, figures 2, 2a.

Obolus (Lingulella) septalis Waucorr, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 331. (Characterized as below as a new
species. )

Obolus meconnelli Waxcorr (in part), 1908, Canadian Alpine Journal, vol. 1, No. 2, p. 244, Pl. I, fig. 2a (not fig. 2, which
represents a specimen of Obolus mcconnelli). (No text reference. Fig. 2a is copied in this monograph, Pl.
XXIII, fig. 3d.)

The dorsal valve is all that is known of this little shell. There are two specimens in. the

collections of the United States National Museum and three in the collection of Bryon E. Walker, "

of Toronto, Canada.

The general form of the valves is much like that of Obolus rotundatus (Walcott) (Pl. XX).
It is distinguished from the latter and other described species by the strong median ridge and
septum of the dorsal valve. The outer surface is marked by concentric striz and lines of growth
and very fine irregular concentric striz that give a minutely rough surface.

This form owes its specific name to the presence of a septum in the dorsal valve.

FORMATION AND LOCALITY.—Middle Cambrian: (14s) About 2,300 feet (701 m.) above the Lower Cambrian and
2,700 feet (823 m.) below the Upper Cambrian in the Ogygopsis zone of the Stephen formation [Walcott, 1908f, p. 210],

at the “fossil bed’’ on the northwest slope of Mount Stephen, above Field on the Canadian Pacific Railway, British
Columbia, Canada.

SS ee

ee

OBOLIDA. 415

: OBOLUS SHANSIENSIS Walcott.

Plate XI, figures 7, 7a-c.

Obolus shensiensis Watcorr, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 327. (Described and discussed as below as a new
species, the spelling shensiensis being in error because the type specimens came from a locality in the Province
of Shansi, not Shensi, although the species occurs in that province.)

General form ovate, with the ventral valve broadly subacuminate and dorsal valve obtusely
rounded. Valves moderately convex in the specimens embedded in a fine-grained, dark lime-
stone. Surface marked by fine, sharp, concentric striz and traces of irregular, obscurely
defined, low, radiating ridges; the interior layers show fine radiating striz and concentric lines;
the shell is strong and built up of numerous lamelle oblique to the outer surface. The largest
ventral valve has a length of 9 mm., width 7 mm. Nothing is known of the interior of the
valves. }

The form, surface markings, and shell structure are much like those of Obolus matinalis
(Hall) (Rl. VIII) and O. tetonensis Walcott (P1. 1X). In outline O. shansiensis is more elongate
than O. matinalis and less so than O. tetonensis.

This form owes its specific name to the occurrence of the type specimen in the Province of
Shansi, China.

FORMATION AND LOCALITY.—Middle Cambrian: (C37) Upper part of the Kichow limestone in dense black lime-
stone nodules in green-gray shales 10 feet below the base of the cliff limestone [Willis and Blackwelder, 1907, p. 146], 8 miles
(12.8 km.) south of Tinghianghien, Shansi; (C32) A fine-grained bluish-black limestone bowlder believed to have come
from the lower part of the Kisinling limestone [Blackwelder, 1907b, p. 272], collected in river drift 1 mile (1.6 km.)
south of Chonpinghien, on Nankiang River, southern Shensi; and (C71) massive cliff-forming limestone in the central
portion of the Kichou formation [Willis and Blackwelder, 1907, pp. 139 and 145 (2d list of fossils)], 4 miles (6.4 km.)
southwest of Tungyu, Shansi; all in China.

OBOLUS SINOE (Walcott).

ee
Plate X XVI, figures 2, 2a-h.

Obolus (Lingulella) sinoe WaucottT, 1898, Proc. U. S. Nat. Mus., vol. 21, pp. 416-417. (Described and discussed as
below as a new species.)

General form broad ovate, with the ventral valve broadly subacuminate and the dorsal
valve broadly ovate. Valves moderately convex, as far as can be determined from the series
of shells preserved in the fine-grained sandstone. A ventral valve 5 mm. in length has a width
of 4.25 mm. A dorsal valve 4 mm. in length has an equal width.

The traces remaining of the exterior shell show it to have been marked by concentric
lines and striz of growth; when the outer layer is exfoliated radiating striz cross the lamelle;
a fragment of the inner surface of the shell indicates that there were scattered pits or puncte
and fine radiating strie; the shell was relatively thick and formed of a thin outer layer and
several inner layers or lamelle, the lamelle of the anterior portion of the shell being arranged in
layers slightly oblique to the outer surface of the shell.

Casts of the interior of the ventral valve show a well-defined area marked by strong flexure
- lines that occur midway between the lateral margins and the narrow, well-defined pedicle groove;
striz: of growth cross the area parallel with its base. The area of the dorsal valve is relatively
short and does not extend very far out on the cardinal slopes. The interior markings of the
ventral and dorsal valves show imperfectly the main vascular sinuses and visceral area, the
central and anterior lateral muscle scars, and a narrow median ridge.

Observations.—This species occurs at the same relative stratigraphic horizon as Lingulella
ino (Walcott) (Pl. XXVI) and is about the same size. It differs, however, in its more circular
form, which is persistent in a large number of shells. In form it more nearly resembles Obolus
rotundatus (Walcott) (P]. XX) of the Upper Cambrian. It differs from that in bemg uniformly

a This species is somewhat doubtfully identified from this locality.

416 CAMBRIAN BRACHIOPODA.

larger and in having a thicker, stronger shell. Some of the shells in the limestone look very
much like Dicellomus politus (Hall) (Pl. LIL) when they are not compressed.

ForMATION AND LOCALITY.—Upper Cambrian: (327) Arenaceous limestone east of Gold Camp, Caballos Mountains,
New Mexico.

(302d) Limestone 200 yards (183 m.) north of the southwest corner of sec. 18, T. 28 N., R. 113 W., Uinta County,
Wyoming.

(14b) Limestone on Cold Creek at north end of gorge opposite the north end of Sponge Mountain, 2 miles (3.2 km.)
south of the San Saba County line, in Llano County; (14e) limestone in Bartlett Hollow, 2 miles (3.2 km.) southeast
of the mouth of Falls Creek, Burnet quadrangle (U. S. Geol. Survey), Lampasas County; (67) sandstone on Tatur
Hill, 7 miles (11.2 km.) northwest of Burnet, Burnet County; (69) limestone near Honey Creek, Burnet County; (71)
limestone in Cold Creek Canyon, Burnet County; (68y) interbedded sandstone and limestone, Packsaddle Mountain,
Llano County; and (70) limestone near Morgans Creek, Burnet County; all in Texas.

Middle Cambrian: (302x) Sandstones near the head of Powder River, Bighorn Mountains, Wyoming.

(11j) Basal part of Bonneterre limestone, Mine Lamotte, Madison County, Missouri.

(11a) Sandstone between First and Armstrong creeks, in the southeast corner of the Maynardville quadrangle
(U.S. Geol. Survey), Union County, Tennessee.

(92x) Conasauga (“‘Coosa’’) shale at Yanceys Bend, Coosa River, southeast of Center, Cherokee County, Alabama.

Oxso.tus smitHt Walcott.

Text figures 38A-C.

Obolus smithi Waucort (in part), 1908, Smithsonian Misc. Coll., vol. 53, No. 3, pp. 62-63, Pl. VII, fig. 9a (uot fig. 9,
which represents a specimen of Micromitra (Paterina) major).« (Described and discussed as below as a new
species. Fig. 9a is copied in this monograph as fig. 38B.)

General form broadly ovate, with the ventral valve obtusely acuminate and the dorsal
valve subcircular, slightly transverse; convexity apparently moderate, judging from the speci-
mens as they occur slightly
flattened out in the calcareous
shales. The shell was rela-
tively strong and formed of a
number of thin layers or
lamelle that, toward the outer
edge of the valve, were more
numerous and gave a scaly

FIGURE 38.—Obolus smithi Walcott. A, Exterior of partly exfoliated ventral valve (U.S.Nat. appearance to the margins of
Mus. Cat. No. 5161la). B, Exfoliated dorsal valve, the type specimen (U.S. Nat. Mus. Cat. the old shells
No. 51611b). C, Partly exfoliated shell showing laminations (U. S. Nat. Mus. Cat. No. ?
51611¢). Surface marked by con-
Figure 38B is copied from Walcott (1908d, P). VII, fig. 9a]. The specimens represented are all centric lines of growth and
from Locality 56c, near Helena, Alabama.

A

numerous very fine, slightly
irregular, undulating concentric ridges upon which numerous very minute papille occur, giving
the surface, under a strong magnifying power, the appearance of being minutely granular.

A ventral valve 6 mm. in length has a width of 6.75 mm. A slightly larger dorsal valve ©

7.5 mm. in length has a width of 8 mm.

As shown in the cast, the area of the ventral valve is very short and divided by a relatively .

strongly marked, narrow pedicle furrow, the edges of which were elevated slightly above the
general plane of the area. The cast of the interior shows that the visceral area was about
two-fifths the length of the valve and that the main vascular sinuses extended rather directly
forward from the umbo nearly to the front of the shell, separating very gradually and bounding
the interior third of the valve. Nothing has been observed of the muscle scars.

The cast of the dorsal valve shows that it had a very short area that extended well out on
the cardinal slopes; that a low central ridge extended a little more than half the length of the
shell and was continued by a slight narrow median ridge; the main vascular sinuses extend
directly and obliquely forward well toward the front of the shell in about the same relative
position as in the ventral valve. The position of the transmedian and anterior lateral muscle

a See note accompanying the second reference in the synonymy of Micromitra (Paterina) major (p. 351) and the note following fig. 25, p. 351.

a

—

OBOLIDA. A417

scars is indicated about halfway between the main vascular sinuses and the posterolateral
margin of the valve.

Observations.—This species is characterized by its finely granular surface, short cardinal
area, and relatively thick shell. It has the general form of Obolus lamborni (Meek) and
Obolus willisi (Walcott), but it differs from both of these species in having a granulated surface
and shorter cardinal area. It appears to be the Lower Cambrian form that is represented in
the Middle Cambrian by Obolus willisi and in the Upper Cambrian by Obolus lamborni.

The specific name is given in honor of Prof. Eugene A. Smith, State geologist of Alabama.

FORMATION AND LOCALITY.—Lower Cambrian: (17b) Rome (‘‘Montevallo’’) formation, 4 miles (6.4 km.) south of

Helena; and (56c) Rome (‘‘ Montevallo’’) formation, along road just north of Buck Creek, 1.125 miles(1.8 km.) northeast of
Helena; both in Shelby County, Alabama.

OBOLUS TETONENSIS Walcott.
Plate IX, figures 5, 5a-d.

Obolus tetonensis Waxtcort, 1901, Proc. U. S. Nat. Mus., vol. 23, p. 684. (Characterized and discussed as below as a
new species. )

Obolus tetonensis Watcotr, 1905, idem, vol. 28, p. 327. (Copy of preceding reference, the species being given as new
and no reference being made to the preceding citation.)

The general form, convexity, and appearance of this species are so much like those of Obolus
matinalis (Hail) (Pl. VIII) that a general description is unnecessary. It varies from that
species in the shorter, more transverse dorsal valve, and the narrower outline of the ventral valve
toward the beak.

This species occurs in great abundance in the thin-bedded limestone in the upper portion
of the Cambrian section of the Teton Range, Wyoming, in association with Billingsella colorado-
ensis (Shumard) and Lingulella (Lingulepis) acuminata meeki (Walcott). The forms from this
horizon are illustrated by Plate X, figures 5, 5a, and 5b. What appears to be the same species
occurs nearly 700 feet lower in the section in a thin-bedded sandstone. Specimens from this
horizon are represented by Plate X, figures 5c and 5d. The dorssl valve (5d) is broader and
more transverse posteriorly than the dorsal valve from the uv ~<r horizon.

This form owes its specific name to its occurrence in the Te.on Mountains of Wyoming.

FORMATION AND LOCALITY.—Upper Cambrian: (161) Limestone or the south side of West Gallatin (Gallatin) River,
northwest of Hamilton on the north side of the Gallatin Valley; (152b)¢ east side of Dry Creek, below Pass Creek,
Threeforks quadrangle (U. S. Geol. Survey); and (148a) limestone of the Gallatin formation at the head of Bostwick
Canyon [Iddings and Weed, 1894, areal geology sheet®], in the Bridger Range, Livingston quadrangle (U. 8S. Geol.
Survey); allin Gallatin County, Montana.

Middle Cambrian: (4m) Sandstones about 150 feet (45.7 m.) above the unconformable base of the Cambrian; and
(4e) limestones about 950 feet (289.6 m.) above the unconformable base of the Cambrian; both in the divide at the head of
Jackson Creek (locally known as Sheep Creek), a creek flowing into Jackson Lake about 0.5 mile (0.8 km.) south of its
northwestern corner, Teton Mountains, Grand Teton quadrangle (U.S. Geol. Survey), Uinta County, Wyoming.

(4h) About 375 feet (114.3 m.) above the base of the Cambrian in limestone interbedded in the Flathead shales of
Peale [1893, p. 21], 1 mile (1.6 km.) north of the junction of East Gallatin and West Gallatin (Gallatin) rivers, 4 miles
(6.4 km.) east-northeast of Logan, Threeforks quadrangle (U. S. Geol. Survey), Gallatin County; and (4x) limestone
interbedded in the Wolsey shale [Weed, 1900, p. 285], at the base of a butte in Belt Park, about 6 miles (9.6 km.)
northwest of Neihart, Little Belt Mountains quadrangle (U. S. Geol. Survey), Cascade County; both in Montana.

(3e) Thin-bedded limestones less than 400 feet (121.9 m.) above the quartzitic sandstones of the Cambrian, at
Ophir, Oquirrh Range, Tooele County, Utah.

(14x) About 400 feet (122 m.) above the bottom of Tombstone Gulch in the Abrigo limestone [Ransome, 1904, p. 3],
in the northwest suburb of Bisbee [Ransome, 1904, areal geology sheet], Cochise County, Arizona.

L OBOLUS TETONENSIS LEDA Walcott.

Obolus tetonensis leda Watcorr, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, p. 63. (Characterized as below as a new
variety.)
This is the Upper Cambrian representative of Obolus tetonensis Walcott of the Middle Cam-
brian of the Teton Mountains. Stratigraphically it occurs over 2,000 feet higher in the Cambrian

a This species is somewhat doubtfully identified from this locality.
b Iddings, J. P., and Weed, W. H., Livingston folio (No. 1), Geol. Atlas U. S., U. S. Geol. Survey, 1894.

62667°—vou 51, pr 1—12——27

418 CAMBRIAN BRACHIOPODA.

section, and the localities are 400 miles apart. The variety leda differs from the species in
having more numerous fine threadlike strize and in haying the ventral valve on the average
more obtuse in old shells.

FORMATION AND LOCALITY.—Upper Cambrian: (30m) About 1,950 feet (584.4 m.) above the Middle Cambrian
and 1,350 feet (411.5 m.) below the top of the Upper Cambrian in the siliceous limestones forming le of the Notch
Peak limestone [Walcott, 1908f, p. 175], on the slopes of Notch Peak, about 5 miles (8 km.) southwest of Marjum
Pass, House Range [ Walcott, 1908f, Pl. XIII], Millard-County, Utah.

OBOLUS TETONENSIS NINUS Walcott.

Plate VIII, figures 11-0; Plate XI, figures 1, la-g.

Obolus tetonensis ninus Waucortt, 1905, Proc. U. 8S. Nat. Mus., vol. 28, p. 328. (Characterized essentially as below as
a new variety.) ;

This variety differs from Obolus tetonensis Walcott and from O. matinalis (Hall) by the
more elongate form of the dorsal valve and the more acuminate form of the ventral valve, the
cardinal slopes of the latter extendmg much farther forward in the variety ninus than in the
two species.

The advanced position of the visceral area in the ventral valve is shown by Plate XI, figure
1b, and in the dorsal valve by Plate XJ, figure 1g. The advanced position of the latter may be
compared with the visceral area of Obolus (Schmidtia) crassus Mickwitz.

FoRMATION AND LOCALITY.—Upper Cambrian: (12m) Arbuckle limestone (in the section 7 miles (11.2 km.) north
of Springer this horizon is about 30 feet (9.1 m.) above the Reagan sandstone), NH. 4sec. 2, T.28., R. 1 E., Ardmore
quadrangle (U.S. Geol. Survey), Carter County; (12k) limestones of the Reagan sandstone (in the section 7 miles
(11.2 km.) north of Springer this horizon is about 225 feet (69 m.) above the porphyry contact and 55 feet (17 m.)
below the Arbuckle limestone), on the west side of Honey Creek, near the southeast corner of sec. 35, T. 15S.,
R. 1 E., Ardmore quadrangle (U.S. Geol. Survey), Carter County; (12n) limestones of the Reagan sandstone (15
feet above 12k in the Springer section), NW. } sec. 1, T. 2S., R. 1 E., Ardmore quadrangle (U. 8. Geol. Survey),
Carter County; and (12p) about 225 feet (69 m.) above the igneous rocks in the limestones of the Reagan sandstone,
at the northwest extremity of the Arbuckle Mountains, about 4 miles (6.4 km.) east of Homer, Carter County; all in
Oklahoma.

(9q) About 10 feet (3 m.) above the porphyry contact and 90 feet (27.4 m.) below the Arbuckle limestone, in
limestones of the Reagan sandstone, in middle of W. 4 sec. 2, T.4.N., R. 13 W.; (9p, 9r, and 9t)@ from 45 to 170 feet
(14 to 52 m.) above the porphyry contact, in the limestones of the Reagan sandstone, in SE. 1 NE. 4 sec. 2, T. 4 N.,
R.13 W.; (9s) about 85 feet (26 m.) below the Arbuckle limestone in the limestones of the Reagan sandstone, near
middle of W. $sec. 13, T.4 N., R. 13 W.; and (9u) about 195 feet (59.4 m.) above the porphyry contact in the lime-
stones of the Reagan sandstone in SH. NE. } sec. 2, T.4 N., R. 13 W.; all about 15 miles (24.2 km.) northwest of
Fort Sill, Comanche County, Oklahoma.

(68) Interbedded sandstone and limestone, Packsaddle Mountain, Llano County, Texas.

(54w) Limestone of the St. Charles formation [Walcott, 1908a, p. 6], about 250 feet (76 m.) above the Middle Cam-
brian on the north side of Twomile Canyon, near its mouth, 2 miles (3.2 km.) southeast of Malade, Oneida County, Idaho.

OBOLUS ? TORRENTIS Matthew.

Obolus torrentis MarrHEW, 1902, Trans. Roy. Soc. Canada, 2d ser., vol. 8, sec. 4, No. 3, p. 94, Pl. I, fig. 1. (Mentioned
as a new species.)

Obolus torrentis MaTtTtHEW, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, p. 76, Pl. VIII, fig. 1.
(Described and discussed as a new species. Fig. 1 is copied from fig. 1 of the preceding reference.) .

The type material representing this form is too imperfect for specific determination. A
crushed and distorted dorsal valve, and the interior of a crushed ventral valve that suggests
Lingulella triparilis (Matthew) (Pl. XLV) are all Doctor Matthew sent me. The difference in
stratigraphic horizon between the shales contaiming O.? torrentis and the shales bearing Lin-
gulella triparilis is not great, and but for the presence of an interbedded mass of “‘felsites” they
would probably have been considered as belonging to one formation.

The specific name is derived from its occurrence near the great falls (torrent) m Dugald
Brook.

FORMATION AND LOCALITY.—Middle Cambrian: (18k) Shales of Matthew’s [1903, p. 15] Coldbrook, above the
great falls in Dugald Brook, Indian River, eastern Cape Breton, Nova Scotia.

a 9r is the type locality.
b The specimens to which Locality 13k was assigned were collected one year later than those described by Doctor Matthew [1902, p. 94]
but from the same locality.

OBOLID2. a A19

OBOLUS TRIANGULARIS Mickwitz.

Obolus triangularis Micxwrrz, 1896, Mém. Acad. imp. sci. St.-Pétersbourg, 8th ser., vol. 4, No. 2, pp. 145-147, Pl. II,
figs. 7-9. (Described and discussed in German as a new species; see below for translation of diagnosis.)

Obolus triangularis inornatus Mickwirz, 1896, idem, pp. 148-149, Pl. I, figs. 10-12. (Described and discussed in
German as a new variety.)

Obolus triangularis Mickwitz, Moprre and Secersere, 1906, Medd. fran Lunds Geol. Faltklubb, Ser. B, No. 2 (Aftryck
ur K. Fysiografiska Sallskapets Handl., N. F., Bd. 17), p. 65. (New locality mentioned in Swedish.)

Obolus triangularis Mickwitz, WestercArD, 1909, Medd. fran Lunds Geol. Faltklubb, Ser. B, No. 4 (Aftryck ur K.
Fysiografiska Sallskapets Handl., N. F., Bd. 20), p. 56. (Locality mentioned in Swedish.)

The original description by Mickwitz follows:

Shells moderately large, slightly grooved, thin, brittle; outline of shell subtriangular, posterior border of shells
rectilinear, not winged; surface slightly shiny, concentric striz in fine ribs, which converge to the border of the’shell,
either diverging or confluent, running somewhat irregularly, separated by deep, rounded grooves; radial strice
dwindling, indefinite. Area large, splanchnoccelic part broad, peduncular groove wide, parallel bordered, opening
toward the inside of the shell. Central proove of the large shell heart-shaped to subpentagonal, slightly swelled. .
Median septum and lateral septa perceptibly developed. Sinus of small shell reaching nearly to the area, corneous
processes ridge-shaped. Combined central places for the attachment of muscles of the large shells are not prolonged
into grooves posteriorly.

Mickwitz states that the shells of this species are very thin and brittle and that in the
enormous mass of loose Obolws conglomerate that he examined at Joa not one thick-shelled
specimen was found. The shell also occurs alone at Reval under the Obolus conglomerate,
and they are so delicate that they can not be taken from the matrix, although it is a very loose,
fine-grained sandstone. The thick shells of the Obolus conglomerate have a more confused
ornamentation and a somewhat wider form. The concentric ribs of the typical form have
the best development near the center of the shell, where they run together and are dotted in
places with indistinct knots formed by the intersection of the irregularly developed radial
striz with the concentric strie. He calls attention to the broad pedicle groove of the ventral
valve, which is of the same type as that of O. pandert Mickwitz, and describes in detail the
interior markings of the valves.

The variety inornatus does not appear to me to be sufficiently distinct to be entered as a
variety.

ForRMATION AND LOCALITY.—Upper Cambrian: (395g) Obolus conglomerate at Joa, near Jegelecht, 12 miles
(19.8 km.) east of Reval; (895i) Obolus conglomerate at Ilgast; and (336i) sandstone below the Obolus conglomerate
proper, at Reval; all [Mickwitz, 1896, p. 147] in the Government of Esthonia, Russia.

(9d) Obolus sandstone at Jaggowal, about 20 miles (32 km.) east-southeast of Reval, Government of Esthonia,
Russia.

(310n) Obolus sandstone? [Moberg and Segerberg, 1906, p. 65], in Dalarne, Province of Kopparberg, Sweden.

OxBOLUS VOLBORTHI Mickwitz.

vu

Obolus volborthi Mickwrrz, 1896, Mém. Acad. imp. sci. St.-Pétersbourg, 8th ser., vol. 4, No. 2, pp. 155-157, Pl. II,
figs. 16-17. (Described and discussed in German as a new species.)

This species is separated from O. eichwaldi Mickwitz on the difference in the character
of the surface. Of this species only three fragments have been found. According to Mick-
witz, it is distinguished from O. eichwaldi by its oval outline and pronounced inclination of
the beak. He gives a detailed description and comparison, to which the student is referred.

The specific name was given in honor of Dr. A. von Volborth.

ForRMATION AND LOCALITY.—Upper Cambrian: (395 [Mickwitz, 1896, p. 157]) Obolus sandstone at Joa, near
Jegelecht, 12 miles (19.3 km.) east of Reval, Government of Esthonia, Russia.

420 CAMBRIAN BRACHIOPODA.

Oxso.ius wituist (Walcott).

vi

Plate XXIII, figures 1, la-j.

Obolus (Lingulella) willisi Waxcorr, 1898, Proc. U. 8. Nat. Mus., vol. 21, pp. 418-419. (Described and discussed

as below as a new species.) 2

General form broadly ovate, with the ventral valve obtusely acuminate and the dorsal
valve almost transversely ovate, the posterior margin being very broadly obtuse; convexity
moderate in the specimens preserved in the calcareous sandstone. Surface of shell marked
by concentric lines and striz of growth, with very fine irregular striz between them; a few
specimens show very narrow, slightly irreeular, interrupted, radiating ridges or undulations
(Pl. XXIII, fig. 1j); immer surface of the shell more or less strongly pitted or punctate. This
character varies greatly in casts from the same layer of shale, as may be seen by comparing
Plate XXIII, figure 1b, where it is extreme, with Plate XXIII, figures la, le, and ih. The
shell, as preserved in the argillaceous shale, is relatively thin.

The largest ventral valve, which is shortened slightly by distortion, has a length of 10
mm.; width, 8.5 mm. A well-preserved dorsal valve 8.5 mm. in length has the same width,
while another associated dorsal valve 6.5 mm. in length has a width of 7 mm.

_ As shown in the casts, the area of the ventral valve is rather long and is divided midway
by a strong cast of the pedicle furrow, and again midway between the pedicle furrow and the
lateral margins by a well-defined flexure line; fine strive of growth cross the area parallel
with its base. The area of the dorsal valve is relatively short and extends far out onto the
cardinal slopes; it is marked by clearly defined but not strong flexure lines. Casts of the
interior of the ventral valve show traces of the visceral cavity (vy) and the main vascular
sinuses (vs). In the dorsal valve a narrow median septum is all that is shown, with the excep-
tion of faint indications of the central and anterior lateral scars (h and j) (Pl. XXIII, fig. 1g)
and what appears to be the transmedian @) (Pl. XXIII, fig. le).

Observations.—This species was at first compared with Obolus lamborni (Meek) (Pl. XXII).
Like that, it has a strongly pitted or punctate inner surface, and the ventral valve has the
same general outline. The dorsal valve, however, is much more transverse and obtuse, and
the central muscle scars in the dorsal valve appear to be somewhat differently located.

This species has considerable vertical range; some of the specimens associated with the
Middle Cambrian fauna in the Conasauga shale are very much lke O. lamborni from the
Rogersville shale of Tennessee.

I take pleasure im naming the species in honor of Mr. Bailey Willis, who for a considerable
time had charge of the work in the region where these specimens were collected by Dr. Cooper
Curtice.

FORMATION AND LOCALITY.—Upper Cambrian: (93) Shales and limestones at the base of the Knox dolomite,

near Jordan’s, just below the ford on Cowan Creek; (93n) shales in the southern part of Jordan’s farm, near Jordan’s
crossroads; srl (93x) shales on the Clarke farm, near the ford across Cowan Creek, about 2 miles (3.2 km.) north of
Jordan’s crossroads; all about 8 miles (12.8 km.) southeast of Center, Cherokee County, Alabama.

(96b) Shales in a railroad cut on the Southern Railway, near Cave Spring, 10 miles (16.1 km.) southwest of
Rome, Floyd County, Georgia.

(122) Shale southwest of Town Knobs, 1 mile (1.6 km.) northwest of Rogersville, Hawkins County, Tennessee.

Middle Cambrian: (146) Conasauga shale on the Jacksonville road, 8 miles (12.8 km.) east of Center; (91) Cona-
sauga shale at Cedar Bluff; (94) shales 0.25 mile (0.4 km.) beyond Steel Ford, Cowan Creek, about 8 miles (12.8 km.)
southeast of Center; and (94a) Conasauga shale, in Coosa Valley, east of Center; all in Cherokee County, Alabama.

(140a) Shales 200 yards (182.9 m.) east of Thomas Mills, 5 miles (8 km.) north of Cave Spring | Hayes, 1902, his-
torical geology sheet], Floyd County, Georgia.

(101b) Rogersville shale, just east of the schoolhouse, 3.5 miles (5.6 km.) southwest of Rogersville, on the road
to Melinda Ferry [Keith, 1896a, areal geology sheet], Hawkins County; (107a and 107b) shales and sandstone of the
Rome formation in railroad cut in Bull Run, northwest of Copper Ridge [Keith, 1896b, areal geology sheet], 11 miles
(17.6 km.) northwest of Knoxville, Knox County; (14a) sandstone of the Rome formation along First Creek Gap,
4 miles (6.4 km.) north-northeast of Knoxville [Keith, 1905, areal geology sheet], Knox County; (106a) reddish-brown
shales in middle of valley east of Shooks Ridge, in Bays Mountains, 10 miles (16.1 km.) southeast of Knoxyille, Knox
County; (74e) shales collected near the State line, 2.25 miles (3.6 km.) north of Peltier, Hstillville quadrangle (U.S.
Geol. Survey), Sullivan County; and (121) Rogersville shale, road just east of Harlan Knob, 4 miles (6.4 km.)
northeast of Rogersville [Keith, 1905, areal geology sheet], Hawkins County; all in Tennessee.

ie a ti

OBOLIDA. 421

OxBoLuUS WoRTHENI Walcott.

Ah Text figures 39A—D; Plate IX, figure 5e.

Obolus wortheni Waxcort, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, pp. 63-64, Pl. VII, fig.17. (Described and dis-
cussed as below as a new species. Fig. 17, the type specimen, is copied in this monograph, Pl. IX, fig. 5e.)

General form subcircular, with the ventral valve very obtusely acuminate and the dorsal
valve slightly transverse; both valves slightly convex. Ventral valve with the beak at the
posterior margin, which rises slightly from the general plane of the margin of the valve; the
minute beak of the dorsal valve is at the posterior margin.

Surface marked by sharp, fine, concentric striz and fine imbricating lines of growth; on
some shells low, irregular, more or less obscure and interrupted radiating ridges occur. Shell
of medium thickness and built up of several layers or lamelle. The average diameter of the
valves is 3 mm.

The interior of the ventral valve shows a short flat area divided midway by a narrow
pedicle furrow; the visceral area, which is about one-third the length of the valve, is shown
only in outline; the :
main vascular sinuses
are strong and situ-
ated about midway
between the median
line and the lateral
margins of the valve ;

2 Cc
the surface outside Ficaure 39.—Obolus wortheni Walcott. A, Exterior of ventral valve (U. S. Nat. Mus. Cat. No. 51638b).
. D B, Exterior of dorsal valve (U. S. Nat. Mus. Cat. No. 51638c). C, Interior of ventral valve (U.S. Nat.
the visceral area 1. Mus. Cat. No. 52431). D, Interior of ventral valve (U. S. Nat. Mus. Cat. No. 51638d).
both valvesis marked The specimens represented by figures 39A, 39B, and 39D are from Locality 54u, that represented by
by fine co neentric figure 39C is from Locality 54t, both near Malade, Idaho.

furrows and large scattered puncte, much like those of Obolus ( Westonia) escasoni (Matthew)
(Pl. XLIX, figs. 1a and laa). The interior of the dorsal valve has a short area with a broad
pedicle groove; strong curved main vascular sinuses extend from beneath the area well toward
the front of the valve; they are subparallel to the margin and are situated about one-third the
distance from the margin to the median line of the valve; the visceral area is outlined in about
one-half the leneth of the valve; a narrow, deep sinus extends from each side of the anterior
end and then curves outward to the front margin (Pl. IX, fig. 5e).

Observations.—This shell was at first thought to be the young of Obolus tetonensis Walcott,
but with the finding of a good series it was found to have a nearly circular ventral valve instead
of subacuminate as in OQ. tetonensis, and it is less convex in the same character of matrix. In
form Obolus worthent resembles Obolus discoideus (Hall and Whitfield) (Pl. XVIII, figs. 6, 6a—d),
but it differs in being more circular in outline and in haying a thinner shell.

The specific name was given in honor of A. H. Worthen.

FORMATION AND LOCALITY.—Upper Cambrian: (5a, &c, 54t, and 54w) Limestone about 250 feet (76 m.) above the
Middle Cambrian; (54x) limestone about 200 feet (60.4 m.) above the Middle Cambrian; and (54u) limestone about
100 feet (30.2 m.) above the Middle Cambrian; all in the St. Charles formation [Walcott, 1908a, p. 6], on the north
side of Twomile Canyon, near its mouth, 2 miles (3.2 km.) southeast of Malade, Oneida County, Idaho.

Middle Cambrian: (54v) Limestone in the lower part of the Bloomington formation [Walcott, 1908a, p. 7], about:

1,600 feet (488 m.) below the Upper Cambrian, on the south side of Twomile Canyon, near its mouth, 2 miles (3.2 km.)
southeast of Malade, Oneida County, Idaho.

Oxsotus zErus (Walcott).

Plate XXV, figures 3, 3a-c.

Obolus (Lingulella) zetus Waucort, 1898, Proc. U. 8. Nat. Mus., vol. 21, p. 419. (Characterized and discussed as
below as a new species.)

This is a small shell that has somewhat the general form of Obolus lamborni (Meek).
It differs, however, in being more transverse across the front, in having a broad, shallow

422 CAMBRIAN BRACHIOPODA.

depression in the dorsal valve, and also in being flattened across the center of the ventral valve.
It occurs at a higher horizon than Obolus (Westonia) chuarensis (Walcott), O. (W.) euglyphus
(Walcott), and Lingulella lineolata (Walcott) of the upper beds of the “‘Tonto” sandstone. It
has more the form of the true Obolus than those species, but its shell is relatively thin and
marked by fine radiating striz. All of its essential characters are well shown by the figures
illustrating the species.

ForMATION AND LOCALITY.—Upper Cambrian: (75) Thin-bedded limestones just below the base of the Ordovician
in the Tonto group, near the water’s edge at the mouth of Kanab Canyon, Grand Canyon of the Colorado, Arizona.

Middle Cambrian: (74) Sandstone about 300 feet (91.4 m.) above the base of the Tonto group, at the head of Nunkoweap

Valley, Grand Canyon of the Colorado, Arizona.
(358b) Limestone on the southwest side of Escabrosa Ridge, 4.5 miles (7.2 km.) west-southwest of Bisbee, Arizona.

OxsoLus? zoprr Walcott.

Plate XXX, figures 16, 16a-b.

Obolella crassa BoRNEMANN [not Hatt], 1891, Nova Acta Acad. Czs. Leop.—Carol. Germanicze Nature Curiosorum,
Bd. 56, No. 3, pp. 439-440, Pl. XIX, figs. 15-17. (Described and discussed in German; see below for translation.
Figs. 16, 17a, and 17b are copied in this monograph, Pl. XXX, figs. 16a, 16, and 16b, respectively, 16b being
the side view of the specimen represented by fig. 16.)

Obolus ? zoppi Waxcort, 1901, Proc. U.S. Nat. Mus., vol. 23, pp. 684-685. (Original description translated and species
discussed as below as a new species.)

The original description by Bornemann follows:

Broadly oval or circular, with somewhat pointed vertex. Shells strongly arched, one somewhat more so than the
other. They are marked with prominent concentric lines; no radial striation is noticed. Found in a red-yellow
sandstone layer not far from the houses of Canal Grande on the road to Punta Pintau, Sardinia.

Tn view of the imperfect state of preservation, a determination can only be based on the outer form, whose habit
agrees with the American species from the Cambrian limestone of Troy.

Bornemann kindly sent me two specimens of this form. They suggest Obolella crassa (Hall)
in form and outline, but the material is too imperfect to identify the species or genus. I find
in one specimen indications of the presence of a high area that rises slightly above the plane
of the ventral valve. In two casts there is nothing to suggest the cast of the pedicle aperture,
which is usually well preserved in casts of the ventral valve of specimens of Obolella atlantica
Walcott. As the material is probably from the Middle Cambrian, a provisional reference is made
to Obolus.

FoRMATION AND LOCALITY.—Middle Cambrian: (354f [Bornemann, 1891, p. 439])¢ Reddish-yellow sandstone near
the houses of Canal Grande on the road to Punta Pintau, island of Sardinia, Italy.

OBOLUS sp. undt. a.

Plate X, figure 4.

A small Obolus-like shell, which occurs in the dark argillaceous shales above the Upper

Cambrian zone of eastern New York, resembles in outline Obolus (Bréggeria) salteri (Holl)
(Pl. XIII) of England and Sweden. All the specimens are flattened in the shale. No distinc-
tive specific characters except a series of well-defined concentric striz are shown.

ForMATION AND LOCALITY.—Ordovician: (338v) Shale 1 mile (1.6 km.) southwest of Middle Granville, Mettawee
quadrangle (U.S. Geol. Survey), Washington County, New York.

OBOLUS sp. undt. b.

A small shell marked by very distinct concentric striz and very faint radiating strie occurs
at the following locality. The material is too imperfect for illustration.

FORMATION AND LOCALITY.—Upper ? Cambrian: (7n) Limestone at Hornet Spring in the Spring Mountain Range,
on road from Indian Spring to Pahrump Valley, Lincoln County, Nevada.

a Specimens from this locality are inciuded in the collections of the United States National Museum.

OBOLIDA. 423

Oxso.tus sp. undt. c.

An exfoliated dorsal valve, probably belonging to the genus Obolus, occurs at the following
locality. The specimen is too imperfect for identification.

FORMATION AND LOCALITY.—Ordovician: (214a) Limestone near the base of the Pogonip limestone in the White
Pine district, White Pine County, Nevada.

i Oxoxvs sp. undt. d.

In the conglomerate limestone near Highgate Falls, Vermont, I collected a single specimen
of the ventral valve of a species of Obolws not unlike the ventral valve of Obolws mxra (Hall
and Whitfield) (Pl. X) of the Rocky Mountain region.

Its surface is marked by numerous fine radiating striz and by distinct, concentric, lamellose
lines of growth. The fossils associated with it in the same fragment of limestone indicate the
Upper Cambrian horizon.

FORMATION AND LOCALITY.—Upper Cambrian: (87’) Conglomeratic limestone 1 mile (1.6 km.) south-southwest of
Highgate Falls, Franklin County, Vermont.

OBOLUS sp. undt. e.

Plate XV, figure 8.

Obolus sp. Kaysxr, 1876, Beitrage zur Geologie und Paleontologie der argentinischen Republik, vol. 2, Paleontol. Theil,

Abth. 1, pp. 9-10, Pl. I, fig. 14. (Described and discussed in German. Fig. 14 is copied in this monograph,

Pl. XV, fig. 8.)

This form is illustrated by a single specimen of what appears to be the ventral valve.
Kayser [1876, p. 9] states that most of the specimens are mere fragments and only the genus
can be determined. He suggests that it may be Obolella, but from our present knowledge of
that genus it is not probable. The figure recalls forms of Obolus matinalis (Hall) and O. anceps
Walcott.

FORMATION AND LOCALITY.—Upper Cambrian: (389b [Kayser, 1876, p. 9]) Sandstone at Tilcuya, Province of Jujuy,
Argentina, South America.
OxBo us? sp. undt. f.

Plate XV, figure 9.

Lingulella sp. KaysEr, 1883, China, by Richthofen, vol. 4, p. 35, Pl. III, fig. 2. (Characterized and discussed in

German. Fig. 2 is copied in this monograph, Pl. XV, fig. 9.)

Kayser [1883, p. 35] states that the remains of this species available for study are too
imperfect to permit accurate description and comparison. ‘The shell preserves traces of radial
striation and strong concentric striz of growth. Attention is called to the fact that it has a
somewhat similar outline to Lingulella nathorsti Linnarsson (Pl. XXX1).

The resemblance to the Obolus described by Kayser [1876, p. 9] from Tilecuya, Argentina, is
noticeable, and like that species it recalls Obolus matinalis (PJ. VIII). Comparison should also

; be made with Dicellomus politus (Hall).
FoRMATION AND LOCALITY.—Upper Cambrian: (332 [Kayser, 1883, p. 35]) Limestone at Saimaki, Province of
Liaotung, China.
OBOLUS sp. undt. g.

Obolus (?) sp. indet., Livnarsson, 1876, Bihang till K. svensk. Vet.-Akad. Handl., Bd. 3, No. 12, p. 16, Pl. III,
fig. 31. (Described and discussed in English. See below for copy of description.)

The original description by Linnarsson follows:

Because of its general shape, I refer to the genus Obolus a species of which the materials are very unsatisfactory,
so that I will not create for it a specific name, though it is easily distinguished from all the primordial Brachiopoda of
Sweden. The best specimen is an interior, somewhat mutilated anteriorly, and with the innermost shell layers partly
exfoliated. Its widthis16mm., the length aboutl4mm. The shell is very slightly convex; its circumference resembles
a sector of a circle; the front is broadly rounded; the slopes forming the beak seem to be nearly straight, and make a

494 CAMBRIAN BRACHIOPODA.

somewhat obtuse angle. The surface is not well preserved in any specimen; judging, however, from some small frag-
ments, I should think that a concentric striation is prevailing, but that there are also radiating ribs. In the inner
shell layers little more than a longitudinal striation is seen; the innermost are perforated by small punctiform pits.
The inner layers are polished and glossy; the outermost seems to be opaque.

FORMATION AND LOCALITY.—Middle Cambrian: (3201 [Linnarsson, 1876, p. 16]) Drift blocks supposed to have come
from the Paradoxides elandicus zone [Linnarsson, 1876, p. 6], at Lillviken, near Oestersund, Province of Jemtland,

Sweden.
BROGGERIA Walcott,« subgenus of OBOLUS.

Obclus (Bréggeria) Waxcortt, 1902, Proc. U.S. Nat. Mus., vol. 25, p. 605. (Characterized as below as a new subgenus.)
Obolus (Bréggeria) Waxcort, 1908, Smithsonian Misc. Coll., vol. 53, No. 4, Pl. XI, and pp. 142 and 144. (Classification
of genus.)

This subgenus differs from the typical forms of Obolus in having a very deep visceral
depression in both valves and a minutely punctate interior surface. A series of shells showing
the effect of compression on the appearance of the interior casts of the valves is illustrated on
Plate XIII.

Type.—Obolella saltera Holl.

The generic name was given in honor of Dr. W. C. Brégger.

OxsoLus (BROGGERIA) SALTERI (Holl).
Plate XIII, figures 1, lan; Plate XV, figures 4, 4a-d.

Obolella salteri How, 1865, Quart. Jour. Geol. Soc. London, vol. 21, pt. 1, p. 102, figs. 9a—b. (Described as a new
species; see below for copy. Figs. 9a-b are copied in this monograph, Pl. XV, fig. 4.)

Obolella salteri Holl?, Davipson, 1866, British Fossil Brachiopoda, vol. 3, pt. 7, No. 1, pp. 61-62, Pl. IV, figs. 28 and
29. (Original description, Holl, 1865, p. 102, copied and species discussed. Fig. 28 is copied from Holl, 1865,
figs. 9a—b.)

Obolella? salteri Holl, Davipson, 1868, Geol. Mag., vol. 5, p. 311, Pl. XVI, figs. 8-9. (Discussed. )

Obolus ? salteri (Holl), Dat, 1870, Am. Jour. Conchology, 2d ser., vol. 6, pt. 2, p. 163. (Discussed.)

Obolella salteri Holl, Pumurs, 1871, Geology of Oxford and the Valley of the Thames, p. 68, Diagram XVII, fig. 11.
(No text references.)

Obolus salteri (Holl,, Bréaaur, 1882, Die silurischen Etagen 2 und 3, pp. 44-45, PI. X, figs. 10, 11, and 13. (Localities
mentioned in German. The specimen represented by fig. 10 is redrawn in this monograph, Pl. XIII, fig. 1m.)

Obolus ? salteri (Holl), Micxwrrz, 1896, Mém. Acad. imp. sci. St.-Pétersbourg, 8th ser., vol. 4, No. 2, p.19. (Discussed
in German.)

Obolella (2) salteri Holl, Martny, 1902, Quart. Jour. Geol. Soc. London, vol. 58, pt. 1, pp. 189-140, figs. 3-6, p. 138.
(Described and discussed.)

Obolus (Bréggeria) salteri (Holl), Waucorr, 1902, Proc. U. S. Nat. Mus., vol. 25, pp. 605-606. (Original description,
Holl, 1865, p. 102, copied as below, and species discussed essentially as below.)

Obolus (Bréggeria) salteri (Holl), Mopmre and SrcrrBere, 1906, Medd. fran Lunds Geol. Faltklubb, Ser. B, No. 2
(Aftryck ur K. Fysiografiska Sillskapets Handl., N. F., Bd. 17), p. 64, Pl. I, figs. 27-80. (Described and dis-
cussed in Swedish.)

Obolus (Bréggeria) salteri var.? WesteRGArp, 1909, Medd. fran Lunds Geol. Faltklubb, Ser. B., No. 4 (Aftryck ur K.
Fysiografiska Sillskapets Handl., N. F., Bd. 20), p. 56, Pl. Il, figs. 17-19. (Discussed in Swedish. Figs. 17
and 18 are copied from Moberg and Segerberg, 1906, Pl. I, figs. 28 and 27, respectively.)

The original description by Holl follows:

Compressed, subtriangular to nearly round, rather broader than long; shell thin; surface grooved concentrically °
by a few inequidistant, strongly marked lines of growth and by numerous finer lines which are distinct only on the
sides of the shell. Length usually about one-third inch, width slightly more.

Position.—In the Black Shales.

Brégger [1882, Pl. X, figs. 10,11, and 13] identified this species from both the Ceratopyge slate
and the Ceratopyge limestone of Sweden. The specimen from the limestone is very beautifully
preserved and appears to be the dorsal valve of this species.

aThe synonymy for this subgenus does not give a complete record of the various genera under which the species now included in Broggeria were
formerly placed; it gives only those references in which the genus is discussed or described. To complete the record the following mere generic
references are listed:

Obolelia Holl [1865, p. 102). Obolus Brogger [1882, p. 44].
Obolella Davidson [1866, p. 61; 1868, p. 163). Obolus? Mickwitz [1896, p. 19].
Obolus ? Dall [1870, p. 163]. Obolella ? Matley [1902, p. 139].

Obolella Phillips (1871, p. 68). Obolus (Broggeria) Moberg and Segerberg [1906, p. 64].

OBOLIDA. 425

I find in the limestone from Slemmestad a broad form of the ventral valve that closely
resembles in outline and surface the shell illustrated by Brégger as “‘ Lingula sp.” [Brégger,
1882, Pl. X, fig. 9], and I think that the specimen represented by figure 12 of the same reference
(‘Lingula sp.”) may also belong to this species.

Through the courtesy of Doctor Brégger, I studied the material representing this species
collected in Norway, including the fine interior of the dorsal valve illustrated on Plate XIII,
figure 1m, of this monograph.

In a collection kindly sent me by Dr. G. Lindstrém I find two ventral valves (Pl. XV,
figs. 4a and 4b) from the black shale of Skane, but itis in the collection made by Mr. Schmalensee
that specimens occur showing the casts of the interior of the dorsal valve. These have the
imprint of the central visceral area, the large vascular sinuses, and the area (Pl. XV, fig. 4c).
A cast (Pl. XII, fig. 1b) of an uncompressed shell proves that the visceral area was short and
relatively small. Comparing the latter figure with Plate XIII, figure 1m, I am led to conclude
that the latter is a partly exfoliated specimen preserving the vascular markings on the thin
inner layers of the shell.

In Cape Breton this species occurs abundantly in association with Lingulella concinna
Matthew and Acrotreta bisecta Matthew. The shells are all compressed in the shale, but a
direct comparison of the interiors of the valves of specimens from Cape Breton and the Cera-
topyge shales of Sweden shows the two to be identical in all characters except the length of the
area and pedicle groove. The Cape Breton shells have a longer area, but whether or not this is
due to the conditions of preservation I am unable to decide, as the material from Sweden is
very imperfect about the area. On one of the Cape Breton shells the fine puncte of the
interior surface are clearly shown.

The specific name was given in honor of Mr. J. W. Salter.

FORMATION AND LOCALITY.—Passage beds between the Upper Cambrian and the Ordovician: (8x) Ceratopyge
limestone at Slemmestad, about 3 miles (4.8 km.) southwest of Christiania; (328i [Brégger, 1882, description of Pl. X])
Phyllograptus slate at Krekling, in Sandsvar; (323e [Christiania Univ. Min. Inst.]) Ceratopyge limestone (Etage 3a7
of Brégger) at Engervik, in the Christiania region; (323f [Brégger, 1882, pp. 16-17]) lower part of the Ceratopyge lime-
stone at Vestfossen, 10 miles (16.1 km.) west-southwest of Christiania; and (328h [Brégger, 1882, p. 17]) blue Ceratopyge
limestone (a higher horizon than 323f) at Vestfossen, 10 miles (16.1 km.) west-southwest of Christiania; all in Norway.

(309 [Moberg and Segerberg, 1906, description of Pl. I]) Ceratopyge limestone (zone 4 of Moberg and Segerberg)
at Fogelsang, 5 miles (8 km.) east of Lund; and (323j [Brégger, 1882, p. 44]) Ceratopyge limestone at Tosterup; both in
the Province of Malméhus, Sweden.

Upper Cambrian: (304e [Davidson, 1866, p. 62]) Upper part of the black ‘‘ White Leaved Oak” shales at Coal Hill,
east end of the Malvern Hills; and (304a [Groom, 1902, p. 110]) ‘‘Bronsil” shales in the Malvern Hills; both between
Herefordshire and Worcestershire, England.

(8q) Shale in Barachois Glen, 4 miles (6.4 km.) south of Little Bras d’Or Lake; (10c) shale on west side of Bara-
chois River; (10d) shales on west side of Barachois River, 0.125 mile (0.2 km.) north of Boisdale road, opposite McMul-
lin’s place; (10m) shales 2 miles (3.2 km.) south of the Boisdale road from Upper Leitches Creek, toward the head
of Barachois River; (10e, 10f, and 10g) shales on the east branch of Barachois River, 0.5 mile (0.8 km.) north of the
crossroad from Boisdale to Upper Leitches Creek; (10i) shale in high bank on west side of Barachois River, just north
of the Boisdale road; (101) shale on east bank of Barachois River, 6 miles (9.6 km.) from Little Bras d’Or Lake; (3h)
shale and shaly limestone on McNeil Brook, 1.5 miles (2.4 km.) east of Marion Bridge; (10n) shale in ravine on east side
of Barachois Glen, 3 miles (4.8 km.) from Barachois; (18h) shale on east bank of Barachois River, 1.5 miles (2.4 km.)
north of Boisdale; and (10r) arenaceous shales of Division C3a? of Matthew at McAdam Shore, East Bay, east of Bras
d’Or Lake; all in eastern Cape Breton, Nova Scotia.

(323w) Black argillaceous shale of Etage 3a at Christiania, Norway.

(390i) Limestone band in Ceratopyge slate at Borgholm; (309j) shale at Alunbruk (alum works); (310d) Ceratopyge
slate at Borgholm; and (321x) Dictyograptus slate at Alunbruk (alum works); all on Oeland Island, Sweden.

(390g [Moberg and Segerberg, 1906, p. 64])% Limestone in the Dictyograptus slate at Sandby, 6 miles (9.6 km.) east-
northeast of Lund; (09h) limestones of the Dictyograptus flabelliformis zone at Fogelsing, 5 miles (8 km.) east of Lund;
(323k [Brégger, 1882, p. 44]) Ceratopyge slate at Tosterup; and (309i) limestones at Sandby, 6 miles (9.6 km.) east-
northeast of Lund; all in the Province of Malmohus, Sweden.

Upper? Cambrian: (3091) Shale collected somewhere in Sweden, exact locality unknown; and (310h) shale col-
lected somewhere (probably Fogelsang) in the old province of Skane, now the Provinces of Malméhus and Christianstad;
both in Sweden.

a Specimens from this locality are included in the collections of the United States National Museum.

426 CAMBRIAN BRACHIOPODA.

PALHOBOLUS Matthew,¢ subgenus of OBOLUS.
[zadacéc, ancient; and Obolus.]

Palxobolus MattHEew, 1899, Bull. Nat. Hist. Soc. New Brunswick, vol. 4, pt. 3, No. 18, pp. 201-202. (Described and
discussed as a new subgenus, likely of Obolus, though that does not appear in the text.)

Palzobolus MatrHEw, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, pp. 140-141. (Copies the
first paragraph of the preceding reference and mentions the form as a subgenus. On subsequent pages (144
and 146) the name occurs as Obolus (Palxobolus).)

Obolus (Palxobolus) (Matthew), Waucotr, 1908, Smithsonian Misc. Coll., vol. 53, No. 4, Pl. XI, and pp. 142 and 144.
(Classification of subgenus. ) 2

Characterized by an approximation of the main vascular canals and surface markings.
The surface is of the same type as that of Obolus (Acritis) antiquissimus (Hichwald) (Pl. XIII),
but the position of the visceral cavity and vascular canals differs materially in the two forms.

Type.—Palzobolus bretonensis Matthew.

OgpoLus (PALHMOBOLUS) BRETONENSIS (Matthew).

Plate XX XII, figures 5, 5a-g.

Palxobolus bretonensis MaTtHEW, 1899, Bull. Nat. Hist. Soc. New Brunswick, vol. 4, pt. 3, No. 18, p. 202, Pl. II, figs.
2a-i. (Described and discussed. ‘The first reference, though it is not described as a new species.)

Obolus bretonensis MattHEW, 1902, Trans. Roy. Soc. Canada, 2d ser., vol. 8, sec. 4, No. 3, p. 95, Pl. I, figs. 5a-e. (Char-
acterized. Figs. 5a-e are copied from Matthew, 1899, Pl. II, figs. 2a-e.)

Palxobolus bretonensis MattHEw, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, pp. 141-143, Pl.
IX, figs. 2a-h. (Original description, Matthew, 1899, p. 202, copied and species redescribed and discussed.
The species is mentioned on p. 143 as Obolus bretonensis. Figs. 2a—h of this reference are copied from Matthew,
1899, Pl. II, figs. 2a-e, 2i, 2g, and 2h. Some of the specimens used by Matthew in preparing his illustrations are
copied in Pl. XXXII of this monograph. Close identification is impossible, but figs. 5, 5b, 5c, and 5e of Pl.
XXXII may represent the specimens used by Matthew for figs. 2b, 2d, 2a, and 2e, respectively, of Pl. IX of his

paper.)

General form rounded ovate, with the ventral valve subacuminate and the dorsal valve
sometimes transversely ovate, the cardinal slope meeting at the beak to form a very broad
angle. Walves moderately convex in all specimens examined. Surface of shell marked by
strong, sharp, elevated, concentric ridges that merge into each other more or less toward the
posterolateral edges of the shell, where they terminate on the margin (Pl. XXXII, fig. 5c);
the space between the ridges slopes rapidly down into the rounded hollow and more gently up
the anterior slope, which gives the effect of a subimbricated surface to the shell; fine radiating
striz mark the space between the ridges, and some of the better-preserved ridges are marked
by faint depressed striz; the irregularity of the ridges is most marked where they inosculate,
especially toward the sides; the inner layers of the shell are marked by concentric lines of
growth and fine radiating striz, and the inner surface by both sets of striz and numerous strong
pits scattered over the surface and gathered like beads on the concentric growth lines. The
shell is formed of the usual thin outer layer and numerous inner layers or lamelle, but it is
usually compressed in the shaly, impure sandstone so as to destroy the details of its lamellated
character. The size and relative proportion of the valves are shown by the illustrations.

Casts of the interior of the ventral valve show a well-defined area that extends well out
on the cardinal slopes; it is divided midway by a strong pedicle groove and again by a clear
but not prominent flexure line; it is also marked by rather strong growth lines parallel to its
base. Casts of the area of the dorsal valve show a rather strong area marked by lines of growth.
The casts of the interior of the valves show (a) a trace of the visceral area of the ventral valve,
(b) the position of the posterior of the main vascular sinuses in the ventral valve, and (ce) a sharp
median ridge and the bifurcation of the scars left by the vessels in front of the anterior lateral
muscle scars in the dorsal valve anterior to the parietal line. The only traces of the muscle
scars are in the dorsal valve, where the centrals and small anterior laterals are faintly shown

aThe synonymy for this subgenus includes only those references in which the subgenus is discussed or described. To complete the record
the following mere references are listed:
Obolus Matthew [1902c, pp. 94 and 95]. Obolus (Palzobolus) Matthew (1903, pp. 144 and 146].

OBOLID. 427

in an elongated shell (Pl. XXXII, fig. 5e). The approximation in position of the main vascular
trunks is an unusual feature but one that, owing to the state of preservation of the material, is
not altogether satisfactorily determined.

Observation.—This is a most interesting species and it is to be regretted that better material
has not been found to illustrate the interior of the valves. The outer surface at once suggests
comparison with Obolus (Acritis) antiquissimus (Hichwald) (Pl. XIII), but that species has.a
strong convex form and a short visceral cavity that is peculiar to it and that caused Mickwitz
[1896, p. 205] to retain Acritis as a subgenus. The size and position of the visceral cavity is
normal for the genus. Matthew [1899, Pl. II, fig. 2e] gives a diagrammatic figure of the dorsal
valve in which he places large muscle scars far forward into the valve. A careful study of his
specimen shows that the vascular canal in front of the anterior lateral scars bifurcates about
the center of the shell. Another specimen laterally compressed (Pl. XX XII, fig. 5e) shows the
central muscle scars in about the center of the shell despite the distortion of the shell. The
positions given them by Matthew [1899, Pl. II] in the broad form of the shell appear to have
been decided by their position in the compressed elongated shell; the same is also true of the
strong median ridge in his figure 2e.

Matthew [1899, p. 201] proposes the subgenus Palzobolus for this species on account of the
“close approximation of the vascular trunks” on the ventral valve. This character is shown
in shells elongated and compressed laterally, but even by making allowance for compression
they are closer than in other forms of the genus.

The specific name is derived from Cape Breton.

ForMATION AND LOCALITY.—Middle Cambrian: (18d’) Sandstones opposite the third waterfall in Dugald Brook,
between divisions H2a and H2b; (10p) sandstones just below the waterfall in Division H2b; (131/ and 344i [Matthew,
1908, p. 143]) sandy shales of Division H3a; and (13n’” and 344b [ Matthew, 1903, p. 142])% Sandy shales of Division
-£3d; all in Matthew’s [1903, p. 21] Etcheminian, on Dugald Brook, Indian River, Cape Breton, Nova Scotia.

(344c [Matthew, 1903, p. 142]) Sandy shales of Division E3d of Matthew’s Etcheminian, on Gregwa Brook, Indian
River valley; (10p’’) sandstone on the small brook on the hill between the bridge over Indian River and McPhees

Brook; and (10r) arenaceous shales of Division C3a? of Matthew at McAdam Shore, East Bay, east of Bras d’Or Lake;
all in eastern Cape Breton, Nova Scotia.

OxsoLUs (PALHOBOLUS) BRETONENSIS LENS (Matthew).

uv

Obolus lens-primus MatruEw, 1902, Trans. Roy. Soc. Canada for 1902, 2d ser., vol. 8, sec. 4, No. 3, pp. 94-95. (Char-
acterized. This is the first reference to this variety.)

Obolus lens MattHEw, 1902, idem, p. 95, Pl. I, figs. 6a-f. (Characterized.)

Obolus (Palxobolus) lens MattHEw, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, pp. 144-146,
Pl. X, figs. la-f. (Described and discussed. Figs. la-f are copied from figs. 6a-f, respectively, of the preced-
ing reference.)

Obolus (Palzxobolus) lens longus MatrHEw, 1903, idem, pp. 146-147, Pl. VII, figs. 4a-b. (Described and discussed as
a new variety.)

Matthew [1902b, p. 95] gives a specific value to the difference in the number and closeness
of the concentric striz on the surface of the shell, but from a study of the types of Obolus (Palzx-
obolus) bretonensis and material representing the surface of O. (P.) lens I do not think lens is
more than a variety of bretonensis. The variety longus is based on specimens that have been
compressed laterally to such an extent as to lose their original outline. With the types before
me I do not feel justified in assigning them as a variety distinct from the variety Jens with
which they are associated. O. (P.) bretonensis occurs in beds between layers containing the
variety lens.

Loper collected a number of specimens of a sheil that may be referred to the variety lens
in Matthew’s assise 2c, in which the concentric strix or ridges are very fine on the umbo, grad-
ually becoming coarser toward the front, where they are of the size of the average in the typical
forms of O. (P.) bretonensis. These shells also vary in outline so as to include the variety
longus. In a layer just below that containing these shells he found a single shell with concentric
ridges stronger and coarser than the average of O. (P.) bretonensis.

4344p is the type locality.

428 CAMBRIAN BRACHIOPODA.

Matthew [1892, p. 94] uses the name Obolus lens-primus for a small shell of this species
which was found in a lower layer of rock. The form is not illustrated or described in his larger
work [Matthew, 1903], and I could not discover from the specimen that it was anything more
than a young shell of the variety lens.

ForMATION AND LOCALITY.—Middle Cambrian: (13e) Sandstones of Division E2c; (131 and 344i [Matthew, 1903,
p. 80]) sandy shales of Division E3a; (344 [Matthew, 1903, p. 144]) sandy shales of Division E3b; and (18n’)@ sand-
stones of Division Be: all in Matthew’s [1903, p. 21] Etcheminian, on Dugald Brook, Indian River, eastern Cape
Breton, Nova Scotia. ;

(18m) Sandstones of Division E3f of Matthew’s [1903, p. 76] Etcheminian, on Gillis Brook, Indian River, eastern
Cape Breton, Nova Scotia. :
FORDINIA Walcott, subgenus of OBOLUS.

Elkania Ford, Waxcorr (in part), 1905, Proc. U. S. Nat. Mus., vol. 28, pp. 321-323. (Described and discussed; see
under Elkania, p. 561, for copy. The text includes reference to species now placed under both Hikania and
Obolus (Fordinia).)

Obolus (Fordinia) Waxcorr, 1908, Smithsonian Mise. Coll., vol. 53, No. 3, pp. 64-69. (Characterized and discussed.

‘as below as a new subgenus.) ¥

Obolus (Fordinia) Waucorr, 1908, idem, No. 4, Pl. XI, and pp. 142 and 144. (Classification of subgenus.)

This subgenus of Obolus is proposed for species having a Lingulella-like outline and form
with the development of a tendency to form a platform or thickening in the valves in connec-
tion with the attachment of the muscles in the ventral valve and a thickening in the posterior
portion of the dorsal valve back of the central muscle scars. The type of the subgenus, O. (/.)
perfectus Walcott (Pl. LXIII, figs. 10, 10a—d), has these characters well developed. The second
species, O. (F.) bellulus (Walcott) (Pl. LI, figs. 3, 3a-f), has the cardinal area of the ventral
valve more united with the visceral area than it is in O. (F.) perfectus, and the raised area in
the dorsal valve is much smaller. In 0. (F.) gilberti Walcott the thickened areas are much’
smaller than in the other two species. These three species represent a form intermediate”
between Obolus (Pls. VII and VIII) and Elkania (PI. LI).

Type.—Obolus (Fordinia) perfectus Walcott.

The subgeneric name was given in honor of Mr. S. W. Ford.

Oxsotus (ForprInrA) BELLULUS (Walcott).

Plate LI, figures 3, 3a-f.

Elkania bellula Waucort, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 323. (Described and discussed as below as a new
species.)

General form elongate oval, biconvex; beaks marginal. Surface marked by fine concen-
tric strie of growth that occasionally form varices and small ridges near the umbo; the mner
layers or lamella have radiating striz in addition to concentric striz.

The shell is relatively thin and small. It rarely exceeds 2.5 mm. in length and a little less
in width; the dorsal valve is somewhat shorter than the ventral.

Ventral valve subacuminate, moderately convex; the interior shows a reversed cardinal
area attached to the bottom of the valve and below the plane of the margins of the valve; the
pedicle groove is strong; the line of demarcation between the cardinal area and the bottom of
the valve is indefinite, as the margin of the area and the body of the shell have been merged
into each other; the transmedian and anterolateral muscle scars are outside the main vascular
sinuses and near the margin of the valve; the central scars and middle and outside lateral scars.
are supposed to have been attached within the area (x) (Pl. LI, figs. 3a, 3b), as in Obolus; the
area is largely on the front slope of the thickening of the umbonal portion of the valve.

The dorsal valve has a short reversed area, as shown in Plate LI, figure 3e; the antero-
lateral muscle scars were probably well advanced toward the front, judging from traces of the
length ef the visceral cavity.

a 18n/ is the type locality, though the specimens in the United States National Museum to which that number is assigned were collected
somewhat later than Doctor Matthew’s.

OBOLIDA. 429

The vascular markings include the main vascular sinuses in the ventral valve and traces
of the visceral area in the dorsal valve.

This pretty little shell is much like a small species of Obolus in its exterior appearance;
the interior connects it with Obolus (Kordinia) perfectus Walcott and O. (F-.) gilberti Walcott.
I know of no species closely related to it.

ForRMATION AND LocALIty.—Upper Cambrian: (7x and 7y)4 Limestone of the Emigrant formation [Turner, 1902,
p. 265], about 2.5 miles (4 km.) southeast of Emigrant Pass; and (7z) limestone of the Emigrant formation [Turner,
1902, p. 265], about 3 miles (4.8 km.) southeast of Emigrant Pass; both in the Silver Peak quadrangle (U. 8S. Geol.
Survey), Esmeralda County, Nevada.

Specimens that are somewhat doubtfully referred to Obolus (Fordinia) bellulus occur at the
following locality:

(54f) 150 feet (45.7 m.) above the Middle Cambrian and 1,075 feet (327.7 m.) below the top of the Upper Cambrian

in the light-gray sandstone forming No. 4 of the St. Charles formation [Walcott, 1908f, p. 193], in Blacksmith Fork
Canyon, about 10 miles (16.1 km.) east of Hyrum, Cache County, Utah.

Oxsotus (FoRDINIA) GILBERTI Walcott.
L Plate LI, figures 5, 5a-d.

Obolus (Fordinia) gilberti Waxcort, 1908, Smithsonian Mise. Coll., vol. 53, No. 3, p. 65, Pl. VII, figs. 15 and 15a.
(Discussed as below as a new species. Figs. 15 and 15a are copied in this monograph, Pl. LI, figs. 5 and 5b,
respectively.)

This shell was first thought to belong with Dieellomus politus (Hall). It differs from that
species in the character of the interior of the dorsal valve and in the narrowing of the umbo
as it merges into the apex. The nearest related species is Obolus (Fordinia) bellulus (Walcott).
It differs from the latter in being more convex and in the narrowing of the umbo toward the apex.

The average size of the ventral valve is from 4 mm. to 5 mm. in length by 3 mm. to 4
mm. in width. The dorsal valve is a little shorter than the ventral.

The generic reference is based on the interior of the dorsal valve, which is similar to that
of O. (F.) bellulus (Walcott). Associated with this species are specimens so distinct that they
are doubtfully referred to the same species.

The specific name is given in honor of Mr. G. K. Gilbert, geologist, of the United States
Geological Survey.

FORMATION AND LOCALITY.—Middle Cambrian: (11n) About 3,000 feet (914.4 m.) above the Lower Cambrian
and 1,400 feet (426.7 m.) below the Upper Cambrian, in the upper part of the limestone forming 1a of the Marjum lime-
stone [Walcott, 1908f, p. 179], in the long cliff 2 miles (3.2 km.) southeast of Marjum Pass [Walcott, 1908f, Pls. XIII
and XV], House Range, Millard County, Utah.

Oxspotus (ForpiniA) PERFECTUS V/alcott.

Plate LXIII, figures 10, 10a—d.

Obolus ( Fordinia) perfectus Watcort, 1908, Smithsonian Misc. Coll., vol.53, No. 3, pp. 65-66, PI. VII, fig.16. (Described
and discussed as below as a new species. Fig. 16 is copied in this monograph, Pl. LXIII, fig. 10a.)

General form elongate oval, biconvex; beaks marginal. Surface marked by concentric
lines and striz of growth that gather irregularly in small ridges on the anterior two-thirds of
adult shells; very fine, obscure, radiating lines are preserved on some specimens of the outer
surface. A shallow, narrow, median sinus occurs on each valve, on which the striz arch slightly
backward. Substance of shell apparently calcareocorneous. The shell is strong and built up
of numerous layers or lamelle that, except toward the beaks, are oblique to the outer layer.

Ventral valve broad ovate, with a rather blunt subacuminate beak; very young shells are
broad oval in outline. Area short, and on the plane of the edges of the valve; it is divided
midway by a narrow pedicle furrow that interrupts the transverse stria of growth.

Dorsal valve a little shorter and more rounded at the beak; area short and marked by
transverse striz of growth. Both valves moderately convex.

e

a7x is the type locality.

430 CCAMBRIAN BRACHIOPODA.

The interior of the ventral valve shows what appears to be a short continuation of the car-
dinal area forward into the valve before the slope into the visceral cavity; it is as though an
area with lines of growth were added to the internal area of the ventral valve of Elkania deside-
rata (Billings) (Pl. Lil, fig. 1). The front margin of the area merges in O. (/.) perfectus into
the thicker shell back of the visceral cavity, much as in O. (F.) bellulus (Walcott). The pedicle
furrow extends forward from the posterior margin across the true area and its anterior exten-
sion to the visceral cavity. The visceral area is bordered by two ridges that diverge from the
sides of the pedicle furrow and extend forward about one-third the length of the valve; these
ridges widen toward the front, and where they terminate there appear to be two or three
minute muscle scars corresponding to the outside and middle laterals and central scars of
Obolus; outside of the ridge there is a furrow that was probably occupied by the main yas-
cular canal, and beyond, two narrow, elongate spaces in which the transmedian and anterior
lateral muscle scars appear to be situated; all the furrows head back against the thickened
shell in front of the cardinal area; the surface of the interior of the valve is marked by con-
centric lines and very fine nadeavting strie.

The dorsal valve (Pl. XIII, fig. 10) has a short strong median ridge in front of the car-
dinal area, and well toward the center of the valve a narrow sharp median ridge; on each side
of the latter where it begins posteriorly a small oval muscle scar (central h) occurs, and at its
anterior end two elongate oval scars (anterior laterals j}) that are larger than the centrals;
on the thickened posterolateral portions of the valve, two small muscle scars (transmedian
and outside and middle laterals, 1 and k) occur close to the outer margin. The surface of the
visceral cavity is smooth, but in front of it the minute irregular vascular markings are very
ornate; a few radiating striz also occur.

The two interiors described are unusually distinct; usually the various parts and scars
are more or less obscure.

This species approaches O. (Fordinia) gilbertt Walcott more nearly than any other species
of the genus. It differs in the presence of the sinus in both valves; in being less convex; in
its less pointed beak; and in its strongly marked interior. It occurs over 1,000 feet higher
up in the section of the Middle Cambrian limestones than O. (f.) gilberti. The interior of its
ventral valve is somewhat like that of O. (F.) bellulus (Walcott) (Pl. LI, fig. 3a), but it differs
from that in having a cardinal area in both valves that has not been merged into the internal
cardinal area.

FoRMATION AND LOCALITY.—Middle Cambrian: (30n and 30n’)@ About 3,750 feet (1,143 m.) above the Lower Cam-
brian and 650 feet (198 m.) below the Upper Cambrian in the shaly limestones forming 1c of the Weeks limestone
[Walcott, 1908f, p. 175]; and (300) about 3,950 feet (1,204 m.) above the Lower Cambrian and 450 feet (137.2 m.) below
the Upper Cambrian in the shaly limestones forming 1b of the Weeks limestone [Walcott, 1908f, p. 178]; both on the
north side of Weeks Canyon, about 4 miles (6.4 km.) soufh of Marjum Pass, House Range [Walcott, 1908f, Pl. XIII],
Millard County, Utah.

LINGULOBOLUS Matthew,> subgenus of OBOLUS.
{Lingula and Obolus.]
Lingulobolus MattHEw, 1895, Trans. Roy. Soc. Canada for 1895, 2d ser., vol. 1, pp. 260-261. (Described and discussed
as a new genus. )
Spherobolus MATTHEW, 1895, idem, p. 263. (Described and discussed as a provisional new genus.)
Obolus (Lingulobolus) (Matthew), Waxcort, 1901, Proc. U.S. Nat. Mus., vol. 23, p.683. (Characterized as a subgenus.)
Obolus (Lingulobolus) (Matthew), Watcort, 1908, Smithsonian Misc. Coll., vol. 58, No.4, Pl. XI, and pp. 142 and 144.
(Classification of subgenus.)

Differs from typical Obolus in the strongly arched and thick valves, and the surface marked
by subimbricated, wavy, concentric lines and striz of growth.

a 80n is the type locality.

b The synonymy for this subgenus does not give a complete record of the various genera under which the species now included in Lingulobolus
were formerly placed; it gives only those references in which the genus is discussed or described. ,T'o complete the record the following mere generic
references are listed:

Lingulella? Billings [1872b, p. 468; 1874, p. 67; Cbolus (Lingulobolus) Walcott [1898b, p. 327],
1882, p. 15]. Lingulobolus Grabau [1900, p. 621].
Lingulepis Walcott [1889a, p. 381). Sphzrobolus Grabau [1900, p. 622).

OBOLIDA. 431

Two species from the Lower Ordovician may be referred to Lingulobolus, namely,
O. (L£.) affinis and O. (L.) spissus.

The thickening of the shell mentioned by Matthew is a common feature in Obolus, and I
do not find the arrangement of the muscle scars to vary materially from those of O. apollinis.

Type.—Lingulella ? affinis Billings.

Osotus (LINGULOBOLUS) AFFINIS (Billings).

Plate XVI, figures 1, Ja-e.

Lingulella ? afinis Bru1nes, 1872, Canadian Naturalist, 2d ser., vol. 6, No. 4, p. 468; fig. 4, p. 467. (Described.)

Lingulella? affinis Bruurnes, 1874, Geol. Survey Canada, Paleozoic Fossils, vol. 2, pt. 1, p. 67, fig. 35, p. 66. (De-
scribed. Fig. 35 is copied from fig. 4 of the preceding reference.)

Lingulella afinis Biutines, 1882, Geol. Survey Newfoundland, Rept. Progress for 1881, Appendix, pp. 15-16. (Copied
from preceding reference.)

Lingulepis affinis (Billings), Waucorr, 1889, Am. Jour. Sci., 3d ser., vol. 37, p. 381. (Mentioned under new generic
name.

eee (Billings), MartHEw, 1895, Trans. Roy. Soc. Canada for 1895, 2d ser., vol. 1, sec. 4, No. 13, pp.

261-262, Pl. I, figs. 4a-b. (Original description, Billings, 1872b, p. 468, copied and species described and

discussed.)

Lingulobolus affinis cuneata MattHEw, 1895, idem, p. 262, Pl. I, figs. 4c and 4d. (Described and discussed. This is
the first reference to this variety.)

Obolus (Lingulobolus) affinis (Billings), Waucorr, 1898, Am. Jour. Sci., 4th ser., vol. 6, p. 327. (New locality men-
tioned.

Lingulobolus ae (Billings), Grawav, 1900, Occas. Papers Boston Soc. Nat. Hist., No. 4, vol. 1, pt. 3, pp. 621-622. -

(Described.)

General form subtriangular, with the ventral valve subacuminate and the dorsal valve
slightly rounded at the beak. There is a little variation in the outline of the valves, some
being slightly longer in proportion to the width. The valves are strongly convex, the dorsal
being the most so. A dorsal valve 30 mm. in length has a convexity of 5 mm.; a ventral valve
of the same length has a convexity of 4 mm. above the plane of the margin.

The surface of the shell is marked by fine radiating striz and concentric lines of growth, and
very fine, concentric, slightly undulating, imbricating strie; when the outer surface of the
shell is exfoliated the surface of the inner layers shows rounded, radiating striz crossed by the
concentric lines of growth, and fine, slightly irregular, concentric strie. The interior surface
over the visceral cavity is marked by minute pits or puncte that in the anterior portion of
the shell are arranged in concentric lines, giving a highly ornamental appearance to the shell
when examined by a strong lens.

The shell is thick, being built up of a thin outer layer and numerous inner layers or
lamelle that are oblique to the outer surface over the anterior and lateral portions of the shell.
There is a strong development of the inner layers of the shell over the visceral area, the impres-
sions of the muscle scars and vascular markings showing on the various layersas though there
had been a rapid deposit of shell substance beneath those parts. Usually the direct point of
attachment of the muscle is deeply impressed in the shell substance, but not always so.

The longest ventral valve in the collection has a length of 30 mm.; width, 25 mm. A
large dorsal valve has a length of 32 mm. and a width of 29 mm.

The interior casts show that the area of the ventral valve is not very clearly defined; it
is rather long and divided midway by a cast of a rather narrow pedicle groove; it is very rarely
that any traces of the area can be observed. The area of the ventral valve is obscure in most
specimens; one example shows that it forms a shelf, the undercut projecting slightly beneath
it so as to form in the cast two rounded projections extending toward the beak, on each side
of the median line, giving very much the same appearance as the same parts in the dorsal valve
of Lingulella granvillensis (Walcott) (Pl. XXII, fig. 1d).

The cast of the visceral cavity of the ventral valve is very much like that of Obolus matinalis
(Hall) and Obolus (Westonia) rogersi (Walcott). The material is somewhat imperfect, but
there is an outline of the heart-shaped cavity (x), and the position of the space including the
central, middle lateral, and outside lateral muscle scars is indicated (Pl. XXII, figs. 1, 1b).

432 CAMBRIAN BRACHIOPODA.

The muscle scars are not so well shown in this species as in the associated Obolus (Lingu-
lobolus) spissus. In the ventral valve the anterior lateral and transmedian scars are so closely
united with each other that they can not be differentiated. It is the same with the centrals,
which appear to be crowded in with the middle and outside laterals. In the dorsal valve the
central and anterior lateral muscle scars are clearly defined, and the position of the trans-
median and the outside and middle laterals is fairly well shown in one specimen. The markings
left on the shell by the vascular system are confined to the main or trunk sinuses, which are
imperfectly represented.

Observations.—Billines [1872b, fig. 4] illustrated an elongate form of the ventral’ valve,
and Matthew [1895b, Pl. I] a shorter ventral valve, and with it, as the dorsal valve, the dorsal
valve of O. (L.) spissus. The form that Matthew [1895b, p. 262] has described as the variety
cuneata is probably a dorsal valve of O. (L.) affinas.

This is one of the largest shells that has been referred either to Obolus or its subgenera. In
form it resembles other cuneate species, but it differs from all in the thickness of the shell and
the slight definition of the cardinal areas of the valves. It is quite probable that if we had a
series representing the stages of growth the young shells would be referred to Lingulella, as
Lingulobolus to me appears to be an extravagant development of a species of Lingulella that
has had unusually favorable conditions for growth. Obolus (Lingulobolus) affinis is associated
with O. (L.) spissus (Billings) and Obolus ( Westonia) rogerst (Walcott).

ForMATION AND LOCALITY.—Lower Ordovician: (114b)2 Sandstone 1 mile (1.6 km.) north of Lance Cove, Great
Belle Island, Conception Bay, Newfoundland.

(326a [Grabau, 1900, p. 613]) Limestone pebbles in a Carboniferous conglomerate north of Fall River, Bristol
County, Massachusetts. ;

Oxso.tus (LINGULOBOLUS) sPissuS (Billings).
Plate XVI, figures 2, 2a-k; Plate XLII, figures 3, 3a.

Lingulella ? spissa BILLiNGs, 1872, Canadian Naturalist, 2d ser., vol. 6, no. 4, pp. 468-469, figs. 5a-c, p. 467. (Described.)

Lingulella? spissa Biuines, 1874, Geol. Survey Canada, Paleozoic Fossils, vol. 2, pt. 1, pp. 67-68, figs. 36a-c, p. 66.
(Described. Figs. 36a-c are copied from figs. 5a-c, respectively, of the preceding reference. )

Lingulella? spissa Bruurnes, 1882, Geol. Survey Newfoundland, Rept. Progress for 1881, Appendix, p. 15, Pl. III,
figs. 12a-c. (Text and figures copied from preceding reference.)

Spherobolus spissus (Billings), MarruEw, 1895, Trans. Roy. Soc. Canada, 2d ser., vol. 1, pp. 263-266, Pl. I, figs. 5a-c.
(Original description [Billings, 1872b, pp. 468-469] copied and species described and discussed.)

Obolus (Lingulobolus) spissus (Billings), Waxcorr, 1898, Am. Jour. Sci., 4th ser., vol. 6, p. 327. (New locality
mentioned.)

Spherobolus spissus (Billings), GRABAU, 1900, Occas. Papers Boston Soc. Nat. Hist., No. 4, vol.1, pt. 3, pp. 622-623.
(Described.) ,

General form ovate, with the ventral valve broadly subacuminate and the dorsal valve
obtusely rounded; valves strongly convex, the dorsal bemg about one-third more so than the
ventral. The proportions of the convexity are shown by the outlines accompanying the figures.
The surface of the shell is marked by concentric lines of growth and very fine undulating, sub-
imbricated, concentric striz and very fine radiating strize, which, crossing the fine concentric
striz, cut the surface up into minute squares or parallelograms. This type of surface orna-
mentation also occurs on one or two of the inner layers of the shell just beneath the outer layer.
The surface of the inner layers, especially that of the lamelle forming the anterior lateral thick-
enings of the shell, is marked by numerous flattened striz and over the central portions by
raised, threadlike striz; the interior of the shell and some of the interior layers are marked
by fine pits or puncte, arranged in more or less concentric lines. In addition, there is a finely
punctate surface that can be seen only with the aid of a high magnifying power.

The shell is formed of a thin outer layer and numerous inner layers or lamelle, the latter,
as oblique lamelle, becoming more numerous over the anterior and lateral portions of the

2114b is the type locality, though the specimens in the United States National Museum to which that number is assigned were collected
much later than the type specimens.

‘

a ee

ee ee ees

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OBOLIDA. : 433

shell. Over the central portion of a ventral valve 13 distinct layers may be counted, and at
the anterior edge of the same shell 15 of the oblique lamellz that are strongly marked by the
radiating striz. The valves vary somewhat in size, outline, and degree of convexity. An
unusually acuminate ventral valve has a length of 20 mm. and a width of 19 mm. A dorsal
valve 15 mm. in length has a width of 16 mm.

Casts of the interior of the ventral valve show a rather narrow area and a strong pedicle
furrow which is broad at the base. The striz of growth on the area are arranged in an imbri-
cated manner, very much as on the area of Obolus prindle: (Walcott). The area of the dorsal
valve is narrow and almost concealed beneath the slightly overarching posterior margin.

The cast of the ventral valve (v) shows roughly the heart-shaped cavity (x) of Obolus
(Pl. XVI, fig. 2k). There are no traces of a median septum in the ventral valve; in the dorsal
valve the septum extends as a low ridge with a sharp crest between the central muscle scars
and forward, so as to divide the anterior lateral scars.

The muscle scars are finely shown in both valves. The umbonal scar of the ventral valve
is divided, as in Obolus, the pedicle scar being situated between the two parts. In the dorsal
valve the umbonal scar is very close to the area and arches slightly backward. The scars of
‘the central muscles are not clearly defined m the ventral valve, owing to their beg crowded
in with the scars of the central and outside laterals. Their position, judging from the location
of the centrals in Obolus, is within the transversely trapezoidal area (c), indicated in Plate XVI,
figure 2j. On the dorsal valve the centrals are large and distinctly defined. on many casts of
the interior of the shell and on partly exfoliated specimens. They are situated near the center
or sometimes a short distance in advance of the center of the shell, on either side of the median
ridge; they are oval in outline, the longer axis diverging slightly outward anteriorly. The
anterior laterals (j) are clearly defined in both valves. In the ventral valve they are very close
to the transmedian, if not actually in contact with them (Pl. XVI, fig. 2k); in the dorsal they
are small and situated on either side of the median ridge a short distance m advance of the
central scars (Pl. XVI, fig. 2h). The middle and outside lateral scars on the ventral valve are
situated in the trapezoidal area (c), but neither is clearly separable in any specimen of the
collection, unless it be in that represented by Plate XVI, figure 2k, where the outside lateral scars
(1) and the middle lateral scars (k) may be present. In the dorsal valve of Obolus, the middle
(k) and the outside (1) laterals are closely united, and they are apparently combined in an
elongate scar at (1) (Pl. XVI, figs. 2a and 2g). This scar corresponds in position with the two
sears in Obolus and it is deeply impressed in the thick shell of this species, much more so than
the large central scars, which apparently were but slightly impressed or else were situated upon
elevations on the inner surface of the shell. Some specimens show the elevation and others
the depression for the same set of scars. The transmedian scars (i) are not so distinctly shown
on most of the specimens of the dorsal valve, as they appear to have been lost in connection
with the deep depression formed by the outside and middle laterals. In one specimen, however,
(Pl. XVI, fig. 2a) they are fairly well defined. In the ventral valve they are closely united
with the anterior laterals (j), but can be distinguished from them.

The markings left on the shell by the vascular system are well preserved in a few casts
of the interior of the valve. The main or trunk sinuses are strong and curved inward a short
distance in front of the visceral cavity. Numerous fine peripheral branches radiate toward
the margin and a few short lateral branches toward the visceral cavity. In a dorsal valve
the main sinuses curve in front of the visceral cavity, very much as in the ventral valve. The
interior lateral sinuses radiate from the main sinus in toward the visceral cavity, and the
peripheral branches extend upward toward the margins. In some specimens where the pro-
jections of the visceral cavity back of the central muscle scars unite with the main sinus there
is an apparent broadening of the sinus that produces a rather sharp angle opposite the central
scars. In the ventral valve the depressed space in front of the visceral cavity is marked by
narrow, radiating, and longitudinal spaces, which apparently were occupied by the anterior
portion of the viscera, as the narrow canals unite toward the heart-shaped cavity and the

62667°—vot 51, pr 1—12. 28

434 CAMBRIAN BRACHIOPODA.

areas occupied by the muscle scars (Pl. XVI, fig. 2)). This latter character is probably what
Mickwitz [1896, p. 69] describes as the longitudinal striation of the area m advance of the
visceral cavity in Obolus. The parietal scar is distinctly shown in advance of the visceral
area of the dorsal valve, where its course may be followed from the median line m front of
the anterior lateral muscle scars to the outward curve to the main vascular smuses, beyond
which it has not been observed. Jn none of the specimens of the ventral valve can the exact
position of the parietal scar be determined.

Observations.—The study of the material which IJ collected at the typical locality in 1888
shows clearly that this species is very closely related to Obolus. It differs in having a smaller
area and somewhat in the form and convexity of the valves. ‘There are no special characters
that do not apparently fall well within the limits of Obolus. There is certainly not more than
a subgeneric difference between the different forms of Obolus and Obolus (Lingulobolus) spissus.

Billings [1872b, p. 467] figured a ventral and a dorsal valve, but furnished a very inade-
quate illustration and description. Matthew [1895b, PI. I] illustrated what appear to be two
dorsal valves, one somewhat more elongate than the other. With a large series of specimens
I am unable to find any ventral valve which shows the characters illustrated by Matthew
in his figure 5a [1895b, Pl. I]. On the contrary, most of them are to be observed in specimens
of the dorsal valve.

ForRMATION AND LOCALITY.—Lower Ordovician: (114b)¢ Sandstone mile (1.6 km.) north of Lance Cove, Great
Belle Island, Conception Bay, Newfoundland.
(326a [Grabau, 1900, p. 613]) Limestone pebbles in a Carboniferous conglomerate north of Fall River, Bristol

County, Massachusetts.
MICKWITZELLA Walcott, subgenus of OBOLUS.

Aulonotreta Kurorea (in part), 1848, Verhandl. Russ.-kais. min. Gesell. St. Petersburg for 1847, No. 12, pp. 278-279.
(Described and discussed in German as a new genus. The species referred to the genus belong with Obolus,
Obolus (Acritis), and Obolus ( Mickwitzella).) :

Obolus Hichwald, Davipson (in part), 1853, British Fossil Brachiopoda, vol. 1, introduction, No. 3, pp. 135-136.
(Deseribed and discussed. As far as they have been identified in this monograph the species referred to the
genus belong with Obolus, Obolus (Acritis), and Obolus ( Mickwitzella).)

Not Thysanota AuBeRs, 1860, p. 63. (Proposed for a genus of the Gastropoda; see Marshall’s Nomenclator Zoologicus,
p. 142.)

Obolus ErcHWALD (in part), 1860, Lethzea rossica, ancienne période, vol. 1, sec. 2, pp. 924-925. (Described im French.
‘The species referred to the genus belong with Obolus, Obolus (Acritis), and Obolus ( Mickwitzella).)

Obolus (Thysanotos) Micxwirz, 1896, Mém. Acad. imp. sci. St.-Pétersbourg, 8th ser., vol. 4, No. 2, pp. 194-195.
(Characterized in German as a new subgenus. See below for translation.)

Obolus ( Thysanotus) Mickwitz, Watcorr, 1901, Proc. U.S. Nat. Mus., vol. 23, p. 683. (Characterized.)

Obolus ( Mickwitzella) Waxcort, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, p. 70. (Copies the original description
of Mickwitz, as below.)

Obolus ( Mickwitzella) Watcotr, 1908, idem, vol. 53, No. 4, Pl. XI, and pp. 142 and 144. (Classification of genus.)

The original degeription by Mickwitz follows:

The subgenus Thysanotos, containing a single species, O. siluricus Hichwald, differs from the Cambrian subgenera
Euobolus and Schmidtia mainly by the fringed anterior border of the growth lamelle of its valves, and by the con-
centric striation arranged parallel to the posterior edge of these lamellee—two features that point to a peculiar organi-
zation of the edge of the mantle. The last-mentioned peculiarity appears also in the subgenus Acritis.

Type.—Obolus siluricus Kichwald.
The subgeneric name was given in honor of the late Dr. A. Mickwitz, of Reval, Esthonia.
OxsoLtus (MickwifzELLA) siLuRIcUS (Eichwald).
Plate XV, figures 1, la-c.

Obolus siluricus E1cHwAup, 1843, Beitrage zur Kenntniss des russischen Reiches, Bd. 8, No. 2, pp. 7-8, Pl. I, figs.
15a-c. (Described and discussed in German as a new species.)

@114b is the type locality, though the specimens in the United States National Museum to which that number is assigned were collected much
later than the type specimens.

b The synonymy for this subgenus does not give a complete record of the various genera under which the species now included in Mickwitzella
were formerly placed; it gives only those references in which the genus is discussed or described. To complete the record the following mere
generic references are listed: :

Obolus Eichwald [1843, p. 7]. Obolus Schmidt [1861, p. 218; 1881, p. 17].
Obolus de Verneuil [1845, p. 290]. Lingula Schmidt [1881, p. 17).
Obolus Eichwald [1859, Pl. XX XVII, figs. 6 and 7). Obolus Mickwitz [1892, p. 60].

Ee

OBOLIDA. 435

Obolus apollinis Eichwald, pp VERNEUI (in part), 1845, Géologie de la Russie d’Europe; by Murchison, de Verneuil,
and-de Keyserling, vol. 2, pt. 3, pp. 290-292. (Described and discussed in French. The reference includes
Obolus (Mickwitzella) siluricus, Obolus (Acritis) antiquissimus, Obolus apollinis, and Obolus apollinis ingricus;
Obolus apollinis being figured.)

Aulonotreta polita Kurorea (in part), 1848, Verhand]. Russ.-kais. min. Gesell. St. Petersburg for 1847, No. 12, pp.
279-282 (not Pi. VII, figs. 10a-f). (Described and discussed in German as a new species. The text includes
Obolus ( Mickwitzella) siluricus, Obolus apollinis ingricus, and Obolus apollinis, the last species being figured.)

Obolus siluricus Exchwaxp, 1859, Lethzea rossica, ancienne période, Atlas, Pl. XX XVII, figs. 6 and 7a-b. (The text
reference accompanying these figures is in the following citation.)

Obolus siluricus Excrwaxp, 1860, Lethea rossica, ancienne période, vol. 1, sec. 2, pp. 927-928. (Described and dis-

cussed in French.)

Obolus siluricus Eichwald, Scumipt, 1861, Archiv fiir Naturkunde Liv-, Ehst-, und Kurlands, Ist ser., vol. 2, p. 218.
(Mentioned in German.)

Obolus siluricus Eichwald, Scamp, 1881, Mém. Acad. Imp. Sci. St.-Pétersbourg, 7th ser., vol. 30, No.1, p.17. (Local-
ity mentioned in German.)

Lingula cf. davisi Salter, Scummpt, 1881, idem, fig. 5, p. 17. (Mentioned in the text.)

Obolus siluricus Kichwald, Mickwrrz, 1892, Mélanges géol. et paléontol. tirés du Bull. Acad. imp. sci. St.-Pétersbourg,
vol. 1, p. 60. (Mentioned in German.)

Obolus (Thysanotos) siluricus (Kichwald), Mrexwrrz, 1896, Mém. Acad. imp. sci. St.-Pétersbourg, 8th ser., vol. 4, No.
2, pp. 195-199, Pl. III, figs. 1-9. (Described and discussed in German; see below for translation. Fig. 9 is
copied in this monograph, Pl. XV, fig. 1b.)

Mickwitz [1896, pp. 195-199] describes the species as follows:

Shells large, very flatly arched, thin, brittle. Outline of shells round, somewhat broadened. Posterior borders of
shells rectilinear, not winged. Tip of the beak of large shell slightly curved inwardly. Surface of shell very lustrous,
like varnish. Concentric striz in sharp-edged ribs, which are separated by flat troughs. These ribs run parallel to
the posterior borders of the growth lamellz and therefore always become shorter toward the anterior borders of the
same. Growth lamellz prettily fringed at the anterior borders; the concentric striz are continued on the fringes.
Area large, quite smoothly striate, slightly excavated at the base of the splanchnoccelic part. Pleuroccelic part of the
area extends far into the lateral borders of the shell. Traces of the pseudo-area lamelle approach the borders of the
peduncular groove, and converge into the tip of the beak. Peduncular groove large, deep, roundly hollowed, inwardly
strongly broadened. Thickening of the shells very slight. Central groove of the large shell indefinitely flat. Corneous
processes and sinus of the small shell strongly receding. Median swelling of the small shell broad and flat, divided at
its anterior half by a broad median groove. Principal vascular traces broad and flat, separated by a median swelling
into two sharp-cut furrows. Places of attachment of the central muscles of the small shell large, circular; those of the
umbonal muscles very coarsely longitudinally striate.

Observations: The large shell of this species reminds one in form of O. apollinis quenstedti, especially of a specimen
whose relative numbers also somewhat correspond with those of O. siluricus. In comparing these numbers, one must
take into consideration that the only large shell of the last-mentioned species, which allowed measurement, is some-
what pressed in from above, so that the heights given in the table of measures may most likely be somewhat too small.
The small shell, however, has a somewhat broader form than the corresponding Cambrian species, and varies in outline
by having the greatest breadth nearer the anterior border.

The exterior surface of the shell of O. siluricws has already been spoken of on several occasions: The crescent-shaped
growth lamellee, which correspond to a vegetative period, run out as in all Obolus shells into the posterior borders of
the shell, which, so to say, inclose them. The law of growth of the growth lamelle, or the seam of the mantle which
produces the same, is plainly here and there the same. Now the aberrancy of this species consists in the fact that the
concentric strize of these lamellze do not converge into the tip of the crescent as the other species—with the exception
of O. antiquissimus—but run parallel to the posterior (interior) border of the lamellee and therefore always become shorter
toward the anterior. It is self-evident that this aberrant plaited formation must have corresponded to an aberrant
character of the seam of the mantle, but what the character of the latter was is unknown. Also the profile of the con-
centric striation of O. siluricus deviates essentially from the other ornamented species of Hichwald’s genus; for example,
O. triangularis shows a regular wavy line in which the crests and troughs of the wave are composed of equal curves.
In O. siluricus, however, the curves of the troughs follow immediately on one another, so that the crests run out into
sharp points. O. antiquissimus, which has an intermediate form, shows the crests of the waves somewhat rounded off
at the point.

The fringes, with which the growth lamellz are ornamented at the close of the vegetative period, correspond with
the radial striation on the interior side of the appertaining lamellz in such a manner that every notch between two
teeth of fringes is equal to a radialfurrow. These radial furrows, which owe their formation to the setze, which are sunk
into the seam of the mantle, are peculiar to all Oboli and were already observed in the impression by Hichwald in all
shells whose upper layer (growth lamella) was broken off. To every notch of the fringe therefore corresponds a seta of
the mantle. The subject can not be followed any further. We also here meet with the peculiar but unknown charac-
ter of the seam of the mantle, which produces a pretty fringe in the vegetative rest; in the period of growth, however,
it produces a lamella which is interrupted at the border, both being furnished with concentric ribs. The teeth of the

436 CAMBRIAN BRACHIOPODA.

fringes, at the anterior border of the adult shell, reach a considerable length (four to five transverse ribs); near the beak
they are only indicated.

The breadth of the growth lamelle of this species varies greatly. One shows in the center of the shell a width of
5.5 mm., while the center lamella of another is only 2mm. broad. This is plainly connected with the relative condi-
tions of nourishment. Independent thereof also here, as with all Obolus species, a diminishing of the breadth of the
lamellze toward the anterior border of the adult shell takes place.

The shells of O. silwricus are very thin, and consequently the development of the inner characters is very slightly
pronounced. Instriking contrast to this peculiarity stands the strongly developed area with the broad, deeply hollowed
peduncular groove, which somewhat diminishes toward the beak.

The surface of the area is smooth at the posterior part, and gives rise to the conjecture that in consequence of a
narrow closing of the shell a mutual attrition has taken place. (Similarly as in O. antiquwissimus, only in a less degree.)
The same conclusion is forced upon one by the deeply hollowed peduncular groove, which allowed, even with the
narrow closing of the shell, sufficient space for the passing of the peduncle; and lastly, the strongly developed longitudi-
nally striate places of attachment of the umbonal muscle. A small shell of a young specimen also shows this place of
attachment distinctly but lacks the striation in the figure.

The beak of the small shell also has in its youth a rectilinear bordered tip. In age this is somewhat worn off, so
that the beak has a round appearance. The area of the small shell is hollowed transversely to the median line and
therefore not exposed to attrition, which is limited to the borders of this shell. Unfortunately this part is only at hand
in the already mentioned young specimen.

The inner characters of O. siluricus are more withdrawn from observation. On the one hand they are, as already
mentioned, very slightly developed; on the other hand sufficient material is lacking. The central groove of the large
shell is very fiat and indefinitely bordered, but is perceptible in both figured specimens.

The principal vascular furrows are more distinctly distinguishable, their central swellings are strongly developed
and rear themselves from the deeply hollowed lateral furrows. In one specimen the secondary vascular traces may be
followed under a magnifying glass. The accessory vessels, radiating inwardly and perpendicularly to the principal
vessels, run rectilinearly to the anterior border, and bend off shortly before reaching the median line, as has been
demonstrated in other species. A shortly branched ramification of the first part of these vessels was only suggestively
perceptible. The outwardly directed accessory vessels run in the known manner. Their opening into the peripheral
canal is not perceptible on account of corrosion of this part of the shell.

Of the remaining visible characters in the figured large shell only the places of attachment of the combined central
muscles are to be mentioned, which, however, can not be analyzed into their elements on account of the deficient pre-
servation of the shell. In their totality, they form a narrow band, which lies before the central groove and is bordered
by the parietal band. This band curves, close to the inner lateral furrows of the principal vessels, rectangularly toward
the back and is widened there considerably. This portion, however, is corroded, so that the exact form of the place of
attachment can not be ascertained.

In the small shell, apart from the already mentioned place of attachment of the umbonal muscle, the large circular
places of attachment of the central muscles may be seen for the first time, and lie near the center of the fragment of the
shell on both sides of the flat median swelling, which is divided by a broad median furrow. The places of attachment
of the anterior lateral muscles are also perceptible, but only suggestively. They already lie in the scaled-off part of
the anterior half of the shell.. On the left above, the elongate, quite deeply sunk place of attachment ofthe transmedian
muscle is also perceptible. Lastly, the beginnings of the principal vascular traces and parietal band, as far as the
inner surface of the shell is intact, may be followed and are also expressed in the figure.

The species owes its specific name to the ‘‘Silurian” age of the beds im which it is found.

FORMATION AND LOCALITY.2—Passage beds between the Upper Cambrian and the Ordovician: ‘‘Glauconite
sandstone” at the following localities: (396) At Baitischport, 30 miles (48 km.) west of Reval; (396a) at Leppiko, near
Leetz, on the eastern side of the Baltischport Peninsula, abowt 25 miles (40.3 km.) west of Reval; (896b) at Fall, 15 miles
(24 km.) west of Reval; (396c) at the mouth of Fahna Brook, east of Fall, about 15 miles (24 km.) west of Reval; and
(396e) in the eastern part of the east Baltic region; all [Mickwitz, 1896, p. 198] in the Government of Esthonia, Russia.

(395x [Lamansky, 1901, p. 617]) Glauconitic sandstone (correlated by Lamansky with the Upper Cambrian Cera-
topyge slate) in the vicinity of Baltischport, 30 miles (48 km.) west of Reval; (895v | Hichwald, 1843, p. 147]) sandstone
on Odensholm Island, about 55 miles (88.6 km.) west of Reval; (896y [Eichwald, 1843, p. 147]) chlorite-bearing sands
in the limestone beds at Reval; (8386f [Hichwald, 1860, p. 927]) pyroxene-bearing sands in the Orthoceratite limestone
beds at Reval; (337i [Schmidt, 1861, p. 218]) green sand at Baltischport; and (96x [Eichwald, 1843, p. 146]) chlorite-
bearing sands in the limestone beds at Baltischport, about 30 miles (48 km.) west of Reval; all in the Government of
Esthonia, Russia.

(395w [Hichwald, 1843, p. 147]) Chlorite-bearing sands in the limestone beds at Pawlowsk; and (395y [Kutorga, 1848,
p. 281]) sandstone on Pulkowa Brook; both near St. Petersburg, Russia.

(368a [Siemiradzki, 1886, p. 672]) Gray sandstone of unknown stratigraphic position or age, in the Polnischen
Mittelgebirge, north of Sandomierz on the Vistula, Russian Poland.

@ Localities 896 and 396a are represented in the collections of the United States National Museum.

toy eT

ek a oa ee

x

OBOLID. 437

ACRITIS Volborth,¢ subgenus of OBOLUS.
[axpezoc, indiscernible.]

Aulonotreta Kuror@a (in part), 1848, Verhand1. Russ.-kais. min. Gesell. St. Petersburg for 1847, No. 12, pp. 278-279.
(Described and discussed in German as a new genus. The species referred to the genus belong with Obolus,
Obolus (Acritis), and Obolus ( Mickwitzella).)

Aulonotreta Kutorga, Morris, 1849, Annals and Mag. Nat. Hist., 2d ser., vol. 4, pp. 316-317. (Characterized and
discussed as a synonym of Obolus.)

Obolus Eichwald, Davipson (in part), 1853, British Fossil Brachiopoda, vol. 1, Roane No. 3, pp. 135-136
(Described and discussed. As far as they have been identified in this monograph the species referred to the
genus belong with Obolus, Obolus (Acritis), and Obolus ( Mickwitzella).)

Obolus ErcHwatp (in part), 1860, Lethzea rossica, ancienne période, vol. 1, sec. 2, pp. 924-925. (Described in French.
The species referred to the genus belong with Obolus, Obolus (Acritis), and Obolus ( Mickwitzella).)

Acritis VotBort#H, 1869, Verhandl. Russ.-kais. min. Gesell. St. Petersburg, 2d ser., Bd. 4, pp. 212-217. (The descrip-
tion and discussion of the genus (in German) is incorporated with that of Obolus (Acritis) antiquissimus.)

Acritis Volborth, Datu, 1877, Bull. U.S. Nat. Mus. No.8, p.11. (Placed asa synonym of Awlonotreta.)

Aulonotreta Kutorga, Dawu, 1877, idem, p.16. (Priority of this generic name over Acritis discussed.)

Acritis Volborth, OEHLERT, 1887, Manuel de conchyliologie, by Fischer, p. 1264. (Described in French.)

Aulonotreta Kutorga, Hatt and CLARKE (in part), 1892, Eleventh Ann. Rept. State Geologist New York for 1891, pp.
243-244. (Described and discussed. As discussed the genus includes species referred to both Obolus and
Obolus (Acritis).)

Aulonotreta Kutorga, Hatt and CLARKE (in part), 1892, Forty-fifth Ann. Rept. New York State Museum for 1891,
pp. 559-560. (Copy of preceding reference. )

Aulonotreta Kutorga, Haun and CLARKE (in part), 1892, Nat. Hist. New York, Paleontology, vol. 8, pt.1, p.82. (De-
scribed and discussed and priority, etc., of generic references discussed. As discussed, the genus includes
species referred to both Obolus and Obolus (Acritis).)

Obolus (Acritis) (Volborth), Mrcxwrrz, 1896, Mém. Acad. imp. sci. St.-Pétersbourg, 8th ser., vol. 4, No. 2, pp. 205-206.
(Characterized and discussed in German as a subgenus; see below for translation.)

Obolus (Acritis) (Volborth), Waxcorr, 1901, Proc. U. S. Nat. Mus., vol. 23, p. 683. (Characterized.)

Obolus (Acritis) Volborth, WaLcort, 1908, Smithsonian Misc. Coll., vol. 53, No. 4, Pl. XI, and pp. 142 and 144. (Classi-
fication of subgenus.)

Mickwitz describes the subgenus as follows:

The subgenus Acritis, like the two preceding subgenera, Thysanotos (= Mickwitzella) and Leptembolon, is based on
a single species, Obolus antiquissimus Eichwald, which, out of all the species of Eichwald’s genus, departs most widely
from the typical species.

The most prominent characteristics of this subgenus—apart from the parallelism of the concentric striation of the
surface of the shell, which it has in common with the subgenus Thysanotos (= Mickwitzella)—consist in the remarkable
shortening of the splanchnoccele, which even in the adult stage of the animal advances but little toward the frontal
edge, and in the different arrangement of the deposit of the thickened lamelle, which impart to the adult shells a
totally different appearance.

The failure to recognize these facts was the main cause of the long controversy over the genus of O. antiquissimus,
which after all threw no light on the subject.

Type.—Obolus (Lucina) antiquissimus Hichwald [1843, p. 142],

Oxso.us (AcRITIS) ANTIQUISSIMUS (Hichwald).
Plate XIII, figure 3; Plate XV, figures 2, 2a-d.

Obolus (Lucina) antiquissimus ErcHwaup, 1843, Beitriige zur Kenntniss des russischen Reiches, Bd. 8, No. 2, pp.
142-144, Pl. IV, figs. la-c. (Described and discussed in German as a new species.)

Obolus apollinis Eichwald, pp VERNEUIL (in part), 1845, Géologie de la Russie d’Europe, by Murchison, de Verneuil,
and de Keyserling, vol. 2, pt. 3, pp. 290-292. (Described and discussed in French. The reference includes
Obolus ( Mickwitzella) siluricus, hihi (Acritis) antiquissimus, Obolus apollinis, and Obolus apollinis ingricus,
Obolus apollinis being figured.)

Aulonotreta sculpta Kurorea, 1848, Verhand]. Russ.-kais. min. Gesell. St. Petersburg for 1847, No. 12, pp. 282-283
Pl. VII, figs. 1la-d. (Described and discussed in German as a new species.)

Obolus apollinis Eichwald, Davipson (in part), 1853, British Fossil Brachiopoda, vol. 1, Introduction, No. 3, Pl. IX,
fig. 285 (not figs. 280-284, which represent Obolus apollinis). (No text reference. Fig. 285 is copied from
Kutorga’s figure, 1848, Pl. VII, fig. 11b, of Awlonoitreta sculpta.)

a The synonymy for this subgenus does not give a complete record of the various genera under which the species now included in A critis were
formerly placed; it gives only those references in which the genus is discussed or described. To complete the record, the following mere generic
references are listed:

Obolus (Lucina) Eichwald [1848, p. 142]. Obolus Siemiradzki[1886, p. 672].
Obolus de Verneuil (1845, p. 290]. Acritis Gagel [1890, p. 22].
Obolus Hichwald [1859, P]. XX XVII, figs. 5a-d]. Acritis Hall and Clarke [1892, p. 82].

438 CAMBRIAN BRACHIOPODA.

Obolus antiquissimus EIcHWALD, 1859, Lethzea rossica, ancienne période, Atlas, Pl. XXXVII, figs. 5a-d. (The
accompanying text is cited in ihe following reference.)

Obolus antiquissimus ErcHwaup, 1860, Lethza rossica, ancienne période, vol. 1, sec. 2, pp. 928-929. (Described and
discussed in French.)

Acritis antiquissima VouBortH, 1869, Verhandl. Russ.-kais. min. Gesell. St. Petersburg, 2d ser., Bd. 4, pp. 212-217,
Pl. XVII, figs. 7-9. (Described and discussed in German, the description of the genus Acritis being incor-
porated with that of the species.)

Aulonotreta sculpta Kutorga, Daut, 1877, Bull. U. S. Nat. Mus. No. 8, p. 16. (Discusses the priority of the generic
names proposed for this form.)

Obolus siluricus (Eichwald), Stemrrapzx1, 1886, Jahrb. K.-k. geol. Reichsanstalt for 1886, Bd. 36, Hit. 4, p. 672.
(Characterized and new locality woemisoned) )

Acritis antiquissima (Eichwald), Gace, 1890, Beitr. zur Naturkunde Preussens, von Physikal.-oekonom. Gesell.
Kénigsberg, 6, p. 22, Pl. I, fig. 1. (Described in German.)

Aulonotreta antiquissima (Eichwald), Haut and CrarKe, 1892, Eleventh Ann. Rept. State Geologist New York for
1891, figs. 246 and 247, p. 244. (Notextreference. Figs. 246 and 247 are copied from Volborth, 1869, Pl. XVII,
figs. 7 and 9, respectively.)

Aulonotreta antiquissima (Hichwald), Hatt and Crarxe, 1892, Forty-fifth Ann. Rept. New York State Museum for
1891, figs. 246 and 247, p. 560. (No text reference. The figures are copied from the preceding reference.)
Acritis antiquissima (Eichwald), Hatt and CrarKe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, p. 82, figs.
35 and 36. (Species discussed, and priority, etc., of generic references discussed. Figs. 35 and 36 are copied

from Volborth, 1869, Pl. XVII, figs. 7 and 9, nagnauitvely.)

Obolus (Acritis) antiquissimus (Eichwald), Mickwirz, 1896, Mém. Acad. imp. sci. St. -Pétersbourg, 8th ser., vol. 4,
No. 2, pp. 206-213, Pl. III, figs. 20-22, 24-29. (Described and discussed in German; see below for translation.
Figs. 20a—b are copied in this monograph, Pl. XV, fig. 2d.)

Obolus (Acritis) antiquissimus ventrosus Mickwitz, 1896, idem, pp. 213-214, Pl. III, figs. 23a—b. (Characterized in
German as a new variety.)

Mickwitz [1896, pp. 206-213] describes this species as follows:

Shells large, strongly arched. Arching of the large shell slighter than that of the smaller. Greatest height of
both shells more toward the beak. Outline of shell broadly oval to round, broader than long, the greatest width
lying more to the anterior border. Beak of the large shell very blunt, laterally rounded; extreme tip of the beak of
the large shell lapping hook-shaped over the rectilinearly worn-off tip of the beak of the small shell. Growth lamelle
very thick, loosely disposed, their anterior sharp-edged borders projecting like a molding on their inner surfaces,
strongly radially ribbed. Concentric striz of the outer surface of the shell in wavy roundish ribs, which run parallel
to the posterior border of the crescent-shaped growth lamellz, growing constantly shorter toward the anterior border
of the same. Anterior and lateral borders sharp-edged, lying in one plane with the worn-off borders of the beak. Pos-
terior borders of the shell massive, broad, projecting inwardly in shape ofa border. Area of both shells strongly devel-
oped, broadly ribbon-shaped, prolonged far into the lateral borders, deeply hollowed, polished on the surface by mutual
attrition. Peduncular groove strongly conical, deeply sunk, inwardly often broadened like a trumpet, traces of the
pseudo-area rectilinear, converging into the tip of the beak, attaining to distinctness as a line of the markation of the
narrow splanchnoccelic and the broad pleuroccelic heads of the layers of the worn area lamellz. Thickening of the
shell extended chiefly to the brachioccele, advancing in scalariformed terraces which follow the contours of the parietal
band; with the large shell forming a thick mass in front of the central groove, and with the small filling out the lateral
angular seams which penetrate into the splanchnoccele.

Splanchnoccele small, crowded back strongly to the beak, reaching under the rimlike projecting posterior border
of the shell. Heart-shaped groove very small, very indistinctly pronounced, often only perceptible in a slightly
expressed furrow between the combined central places of attachment—the projecting tip of the central groove. Median
swelling of the small shell beginning as a distinctly developed roundish ridge under the hollowed area, between the
places of attachment of the central muscles, which are there situated, and ending with a fine short furrow between the
places of attachment of the anterior lateral muscles, which are also moved very far back. Principal vessel furrows
of both shells deeply sunk, hollowed into plainly round or flat furrows; in the large shell more approximated to the
median line and running rather straight; in the small shell more approximated to the lateral borders. Secondary
vessels not ramified, radiating inwardly and outwardly perpendicularly to the principal vessels.

Peduncular muscles fastened to a toothlike process, which is pushed before the opening of the peduncular groove
and reaches freely into the splanchnoceele. The places of attachment of the umbonal muscle, in the large shell, on
both sides of the place of attachment of the peduncular muscle on the narrow sides (perpendicular to the plane of the
shell border), which stands out into the interior of the shell; in the small shell on a platform, which lies opposite to
the place of attachment of the peduncular muscle and projects into the interior like a pier. Combined places of attach-
ment of the transmedian and anterior lateral muscles with the large shells in front of the divided places of attachment
of the umbonal muscles on the narrow side of the projecting rimlike border of the shell; with the small shell at
the corresponding place in similar position to the places of attachment of the transmedian muscles; and in front of
these the combined places of attachment of the middle and outside lateral muscles. Places of attachment of the
central muscles in the large shell behind those of the outside lateral muscles, lying on both sides of the projecting

4

ee rer er ee en EE EEE eee

OBOLIDA. 439

tip of the central groove. Both places of attachment narrow, long drawn out, and placed transversely to the shell.
On the facing ends of the places of attachment of the outside lateral muscles and divided by the projecting tip of the
central groove the small, round, quite deeply depressed places of attachment of the middle lateral muscles. Places of
attachment of the central muscles in the small shell moved far into the excavated tip of the beak, lying under the
platform which serves the umbonal muscle as a place of attachment; very much prolonged, divided from one another
by the median swelling. Places of attachment of the anterior lateral muscles of the small shell likewise moved very
far toward the posterior, lying about in the posterior third of the shell, divided by a fine furrow at the end of the
swelling.

Parietal band moved away from the places of attachment in its anterior part, coursing at the border of the scalari-
formed terraces of thickening.

Observations: The immature shells of this extraordinary species show unmistakably the characters of the genus
Obolus, while these latter are not so easily distinguished in adult individuals. This is especially the case with the
characters of the inner surfaces of the shell, which acquire an entirely altered appearance in consequence of the
formation of the shell, which varies in age, and the altered disposition of the thickening of the shell.

The relative height of the adult shell is larger than that of the young. In the same mentioned specimens it amounts
to 0:171; 0:307; 0:262. The falling off of the arching to the tip of the beak is very flat with the young shell; with
the old, as a rule, perpendicular. However, essential aberrances take place with the adult individuals; some show
the falling off of the beak considerably flattened.

As with all other ornamented species, the ornamentation of the outer surface of the shell is altered with the advanc-
ing age of the animal. The delicate concentric striation has no waves until the close of the first vegetative period and
reminds one with its parallelism (in a strict sense) of that of O. silwricus. At times, however, it shows some irregu-
larities, as the parallel uniformly curved ribs at times flow together or become disturbed. With the beginning of the
second vegetative period the waves occur, which, however, are often disturbed in form, and are resolved into separate
small swellings. This ornamentation Volborth has fitly named “‘undulate-humped.” Toward the anterior border
the swellings are crowded again, the waves become smoother, and the concentric ribs flatten, so that the ornamentation
is almost lost close to the anterior border.

The construction of O. antiquissimus, in comparison with the other Oboli, is somewhat negligent, if we may use that
term. The growth lamelle lie very irregularly on one another and protrude very unequally with their anterior sharp
borders; at the same time the coherency of the lamellz is so loose that they fall apart at the least occasion. The
irregularity of the construction of the shell is shown principally at the posterior borders, at which the lamelle are
displaced perpendicularly under one another, and on account of unequal stratification give the appearance of the leaves
of an uncut book.

The individual rings of the growth lamellz (taking the latter as a whole, not only the visible parts on the surface
of the shell) are very massive with O. antiquissimus, and are club-shaped toward the beak, in the profile, as with
other species. But while in the remaining species they at the same time become narrower (crescent-shaped) toward
the beak, they here retain their breadth to the traces of the pseudo-area of the area lamellz and then pass over (in
the splanchnoccelic part of the area of the base) into a position perpendicular to the plane of the border of the shell.
The breadth of the rings (surface of displacement) increases with the advancing age of the shell, independently of
whether the existing vegetative period produces a.thin or thick lamella. The thickness is understood as the perpen-
dicular distance between the surfaces of separation.

According to this, the construction of the shell takes place as follows: At the anterior border the growth lamelle
are separated in ordinary manner, each one sticking halfway under the preceding one. Toward the posterior the
individual rings are pushed more and more below one another until they lie perpendicularly below one another at
the posterior borders of the shell. Now, as every new ring surpasses the preceding in breadth, and the splanchno-
ceele is nominally reduced in thickness, the rings, which lie perpendicularly upon one another, form a very mas-
sively hollowed border, similar to a rim, at the posterior borders of the shell, which is also continued even in the
beak. There, however (between the traces of the pseudo-area), they are built up by the lamell of the splanchno-
ceelic part of the area, which lie in front of one another, perpendicular to the plane of the border of the shell. In
the umbonal part of a small shell the described lamellz (which lie over each other) of the posterior lateral borders,
as well as the posterior border of the shell which is formed by the splanchnoccelic area lamelle, thay be seen
distinctly. :

A principal distinction between the construction of the shell of O. antiquissimus and that of the other species is
not present. The strengthening of the principal part of the shell (which incloses the visceral cavity) takes place with
the first named through strengthening of the outer lamellz at the expense of the inner thickening, but with the other
species through strengthening of the inner thickening at the expense of the outer lamellz. :

A noteworthy appearance, which has only been noticed with O. antiquissimus, deserves to be emphasized. The
ring-shaped lamellze of the anterior part of the shell consist of rock-mass (limestone), but are, as all lamella, clothed
with a homogeneous (corneous) layer, so that it gives the impression that the individual lamelle had been hollow
and after the death of the animal had been filled with calcareous mud. It is, however, more likely that the inner
layer of the canal, which is less capable of resistance, was dissolved after the death of the animal and restored by the
penetrating calcareous mud.

In still greater measure than through the just described formation of the border the configuration of the inner surface
of the shell becomes altered through the disposition of the lamelle of thickening, which deviates in the age of the

440 CAMBRIAN BRACHIOPODA.

animal. The large shell of a youthful specimen is not essentially distinguishable in the general arrangement of the
characters from the typical species, unless stress be laid on the extraordinarily strongly shortened splanchnoceele. In
one specimen a slight swelling is already noticeable, which, however, does not extend to the splanchnoceele, but,
moved from the places of attachment of the muscle far to the front, lies in the brachioceele. Another already shows
the beginning of the formation of terraces in the form of two slight obliquely placed swellings, which are connected in
advance growth and widen out to a surface whose border (which faces the beak and falls off perpendicularly) shows
an inlet corresponding to the protruded tip of the central groove in the median line of the shell. In further growth
of the shells one terrace is built upon the other, each following the other scalariformly, receding from the border of
the preceding one and thus gradually forming the mass. This thickening of the shell is extended only on the central
part of the shell. At both sides deep, broad furrows remain, which are retained for the principal vessels. Most likely
the mass is gradually flattened toward the anterior border. Unfortunately, all specimens are injured in such a tanner
that nothing definite could be ascertained.

With the small shell the thickening takes place in entirely similar manner. Here the terraces are chiefly separated
by the lateral angular places of the brachioccele, which are formed by the protruding splanchnoccele and form a mass
scalariformly sloping, which cuts deep into the protruding splanchnoccele. A youthful specimen of the small shell
shows a strongly developed mass, which, however, was for the greater part destroyed by the treatment with dilute

hydrochloric acid. This manner of preparation was chosen to lay bare the posterior parts under the deeply hollowed _

umbonal border, which was also satisfactorily accomplished at the expense of the strongly weathered lamelle of
thickening.

Of the characters whose development is connected with the thickening of the posterior part of the shell, as the
septa, corneous processes, and heart-shaped groove, nothing is to be discovered in the adult shells of O. antiquissumus.
In young specimens, however, the central groove is mostly distinguishable, even if it is always very small, flat, and
indefinitely bordered.

The principal vessels are sunk in the small shells in the usual manner, but are not divided by a middle swell-
ing. With the adult they run in deep furrows at both sides of the central mass. Their course can not be followed in
the anterior half of the shell on account of the injured condition of the shells. The accessory vessels and the peripheral
canal are only perceptible in indistinct traces. The former seem to run without branching, and perpendicularly to the
principal vessels.

~ The places of attachment of the muscles of O. antiquissimus have in general the same Peeaeetent as those of the
typical species. In the latter those which lie more toward the center of the shell and toward the anterior are,
however, corresponding to the disposition of the splanchnoccele, strikingly long drawn out. :

The peduncular muscle and the divided umbonal muscle are attached in the young shells exactly in the same
manner and at the same place on the bottom of the shell of the ventral valve as in the other species. In further
growth of the shells small elevations are formed at th’e places of attachment. The progressing development of these
elevations may be followed in a series of shells. The center one of these elevations is gradually altered through corre-
sponding attachment of the lamelle into a toothlike process, which reaches in front of the peduncular groove freely
into the splanchnoccele and serves the peduncular muscle as a place of attachment. The places of attachment of the
divided umbonal muscle have gradually moved to the rimlike border of the shell (close to the peduncular furrow),
whose narrow sides are turned inward. The combined spots of attachment of the transmedian and anterior lateral
muscles of the large shell undergo the same change of place. ;

The case is entirely similar with the places of attachment of the small shell, which lie a the base of the area, and
the pleurocele (umbonal, transmedian, outside lateral, and middle lateral muscles). They all move, in the adult indi-
viduals, into a place corresponding to their position in the youthful shell, to the narrow side of the rimlike border
which surrounds the posterior part of the shell. The place of attachment of the umbonal muscle acquires, aside from
this, a special broadening in the form of a pier-shaped platform, which protrudes into the inside of the shell. The
pierlike construction gives this place of attachment of the umbonal muscle, which (judging by the mutual attrition of
the beaks) displays a considerable strength, a special firmness.

All these places of attachment, which lie at the border of the shell, are grained like shagreen, coffee-brown colored,
and covered with small, lustrous, dark-brown knots.

More important than those just described is (in comparison with the typical species) the dislocation of the places
of attachment, lying in the interior of the shell. They all are, in consequence of the extraordinary shortening of the
splanchnoceele of this species, pushed back so far toward the beak that (especially with the small shell) an entirely
distorted figure of the typical figure is brought about. The position of the combined central places of attachment of
the large shell is in this regard less striking. The latter are, to be sure, moved so near to the area that only a small
triangular space is left for the central groove, but the difference between this arrangement and that with O. celatus
orbiculatus is, however, proportionately slight. Of greater importance is the aberrancy in the opposed position of the
individual spot of attachment of this complex, in which, as already often mentioned, the places of attachment of the
central muscles are arranged behind those of the outside lateral muscles. The combined central places of attachment
could not be demonstrated in the only adult specimen of the large shell; they are lost in the strongly developed
configuration of the inner surface.

The small shell, on the other hand, presents an entirely singular view. The strongly developed places of attach-
ment of the central muscles are, with the young shells, pushed back to the most posterior part of the splanchnoceele,
and lie under the platform which serves the umbonal muscles as a place of attachment, and which covers the same.

E
:

OBOLIDA. 44]

Tn the first-mentioned specimen, the entire posterior part is broken off, so that the long-drawn-out elliptic places of
attachment (immediately in front of the foot of the broken-off platform) are visible. The second specimen had to be
figured from a front view, to make the coyered places of attachment visible. Between the places of attachment of the
central muscles (which in O. antiquissimus lie nearer one another than with the other species) the slightly developed
but distinctly visible median swelling comes in and is produced in the known manner as far as between the places of
attachment of the anterior lateral muscle, which are also moved considerably toward the posterior.

FORMATION AND LOCALITY.t—Passage beds between the Upper Cambrian and the Ordovician: ‘‘Glauconite
limestone” at the following localities: (396i) At Fall, 15 miles (24 km.) west of Reval; (396d) ¢.at Domelint, in Reval;
(396h) at Tischer, 10 miles (16 km.) west of Reval; (396j) at No6mmeweske, near Palms; (337h [Hichwald, 1860,
p. 929]) Orthoceratite limestone near Reval; and (3960) in the entire western part of the east Baltic region; all in the
Government of Esthonia, Russia.

(396k) ‘‘Glauconite limestone” at Iswos on the Wolchow; (396z) limestone in the vicinity of Zarskoe Selo; (395w)
chlorite-bearing sands in the limestone beds at Pawlowsk, near St. Petersburg; (386e) Orthoceratite limestone at Pul-
kowa, near St. Petersburg; and (3961) “glauconite limestone” at Pulkowa, near St. Petersburg; all in the Government
of St. Petersburg, Russia. : :

(396m) ‘‘Lower lenticular layer” of the ‘‘glauconite limestone” at Saggad, east of Palms; (396n) white limestone
between the ‘‘glauconite limestone” proper and the sandy representatives of the “‘ Vaginatum limestone,”’ at Leppiko,
near Leetz, on the eastern side of the Baltischport Peninsula, about 25 miles (40.3 km.) west of Reval; (396g)
upper limestone at Reval; (396x) chlorite-bearing sands in the limestone beds at Baltischport, about 30 miles (48 km.)
west of Reval; (396y) chlorite-bearing sands in the limestone beds at Reval; (336d) Orthoceratite limestone at Reval;
and (396p) strata between the “‘lower lenticular layer” and the “‘ Vaginatum limestone” proper, at N6mmeweske, near
Palms; all in the Government of Esthonia, Russia.

(386b) Drift blocks of “glauconite limestone” near Wehlau, 30 miles (48 km.) east of Konigsberg, Bast Prussia,
Germany.

Oxpo.us (Acritis?) RuGATUS Walcott.

Plate XIII, figure 2.
Obolus (Acritis ?) rugatus Waucort, 1901, Proc. U. S. Nat. Mus., vol. 23, p. 694. (Characterized as a new species.)

The concentric surface lines which are the characteristic feature of this shell, although
much coarser, are the same type as those of O. (Acritis) antiquissimus (Hichwald) and terminate
on the posterolateral margins in much the same manner. It is a very rare form, only one
specimen having been collected, although the beds in which it occurs were very thoroughly
searched during the survey of the Eureka mining district. All that is known of the species is
shown by the figure illustrating it. It is probably not an Acritis and probably not an Obolus.
The peculiar surface, as shown in Plate XIII, figure 2, is very much like that of a Silurian species
named by Clarke Glossina acer.?

This form owes its specific name to the coarseness of the concentric surface lines.

ForMATION AND LOCALITY.—Middle Cambrian: (58) Shaly limestone in upper beds of Secret Canyon shale, east
side of New York and Secret canyons, Eureka district [Hague, 1892, Atlas], Eureka County, Nevada.

SCHMIDTIA Volborth,¢ subgenus of OBOLUS.

Schmidtia VouBortsH, 1860; see Marshall’s Nomenclator Zoologicus, p. 137.

Not Schmidtia BatsaMo-CrIvELLI, 1863. (Proposed for a genus of Porifera.)

Schmidtia VouBortH, 1869, Verhand]. Russ.-kais. min. Gesell. St. Petersburg, 2d ser., Bd. 4, pp. 208-209. (Discussed
in German.)

Schmidtia Volborth, Dawu, 1877, Bull. U. S. Nat. Mus. No. 8, p. 62. (Notes on use of generic name Schmidtia).

Schmidtia Volborth, Zirrev, 1880, Handbuch der Palzeontologie, Bd. 1, Abth. 1, p. 665. (Described in German.)

Schmidtia Volborth, Oruurrt, 1887, Manuel de conchyliologie, by Fischer, p. 1263. (Described in French.)

Schmidtia Volborth, Hatt and CiarKe, 1892, Eleventh Ann. Rept. State Geologist New York for 1891, p. 244.
(Described. )

Schmidtia Volborth, Hatt and CrarKe, 1892, Forty-fifth Ann. Rept. New York State Museum for 1891, p. 560. (Copy
of preceding reference.)

a Locality 396d is represented in the collections of the United States National Museum. With the exception of Locality 337h the remaining
localities are cited from Mickwitz [1896, p. 213).
b Clarke, J. M., New York State Museum, Memoir 9, 1908, pp. 214-215, Pl. XLVII, figs. 7 and 8.
¢ The synonymy for this subgenus does not give a complete record of the various genera under which the species now included in Schmidtia
were formerly placed: it gives only those references in which the genus is discussed or described. To complete the record the following mere generic
references are listed:
Ungula Pander [1830, p. 59]. Obolus Wiman [1902, pp. 62 and 63).
Obolus (Lingulella) Walcott [1898b, Pl. X XVI, Obolus Moberg and Segerberg [1906, p. 65).
figs. 1 and 2]. Obolus Westergard [1909, p. 56].

449 CAMBRIAN BRACHIOPODA.

Schmidtia Volborth, Hatt and CuarKeE, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, p. 83. (Discussed.)

Obolus (Schmidtia) (Volborth), Micxwirz, 1896, Mém. Acad. imp. sci. St.-Pétersbourg, 8th ser., vol. 4, No. 2, p. 158.
(Described and discussed in German; see below for translation.)

Obolus (Schmidtia) (Volborth), Watcort, 1901, Proc. U. S. Nat. Mus., vol. 23, p. 683. (Characterized.)

Obolus (Schmidtia) (Volborth), Watcotr, 1908, Smithsonian Misc. Coll., vol. Ds No. 4, Pl. XI, and PP. 142 and 144.
(Classification of genus.)

The original description by Mickwitz follows:

The subgenus Schmidtia, out of all the subgenera of Hichwald’s genus, is most closely related to the subgenus Hu-
obolus. Some species of that subgenus, especially O. celatus and to a less degree O. crassus, show in their general appear-
ance so much resemblance to O. apollinis that they might pass for miniature models of it. The other two species, on
the contrary, depart from the typical species in the form of the valves and in the shape of the area; O. obtusus, in outline
and in the flatness of its valves, rather resembles Lingula, while O. acwminatus has a very peculiar form, differing from
all Oboli, and due in part to the peculiar conformation of the apex:of the beak.

The main arguments for establishing a special subgenus Schmidtia alongside of the subgenus Huobolus, aside from
the extraordinary smallness of the valves, are: the absence of radial striation of the surface of the valve; the absence of
longitudinal striation from the slope of the thickened posterior part of the valve, as well as of the posterior edge of the
central pit; the invariably more uniform thickening of the valves, manifested in this, among other things, that the
pleuroccelic parts of the valves differ in nothing from the frontal and side edges; the fact that the area of the large valve
is broken in the plane of the pedicle furrow; the pit-shaped depression of the splanchnoccelic part of the area of the
small valve; the pestle-shaped form of the central pit; the recession of the horn-shaped projections and of the sinus of -
. the small valve, while the median ridge simultaneously predominates. A further difference seems to exist in the
different conformation of the inward-radiating secondary vessels, which in some species of the subgenus Schmidtia are
variously ramified, whereas in the subgenus Huobolus, so far as can be seen, they are more rectilinear and less branched.
Still the knowledge of these organs in the species of the two subgenera is as yet too imperfect to permit a definite
statement.

Type.—Schmidtra celata Volborth.

Observations.—The reasons stated by Mickwitz [1896, p. 158] for establishing Schmidtia as
a subgenus of Obolus are essentially those that differentiate it from Lingulella. The species of
the latter subgenus are radially striated and the shells are uniformly thimner. So far as known,
all of the species of Schmidtia are those described by Mickwitz from the Obolus beds of Russia.
In order to place before the student full details of the species, I have had drawings made from
the original specimens received from Mickwitz, and have also introduced the greater portion of his
detailed descriptions. In order also that there may be a reference in this monograph to the
varieties Mickwitz has determined, these are included in the synonymy of the different species
referred to Schmidtia.

The subgeneric name was given in honor of Dr. Fr. Schmidt, of St. Petersburg, Russia.

Oxsoius (SCHMIDTIA) ACUMINATUS Mickwitz.

Plate XIV, figures 2, 2a-c.

Obolus (Schmidtia) acuminatus Mickwirz, 1896, Mém. Acad. imp. sci. St.-Pétersbourg, 8th ser., vol. 4, No. 2, pp. 179-
183, Pl. II, figs. 39 and 40. (Described and discussed in German as a new species; see below for translation.)

Obolus (Schmidtia) acwuminatus alatus Mickwirz, 1896, idem, pp. 183-184, Pl. II, figs. 41 and 42. (Described and dis-
cussed in German as a new variety.) ~

Obolus (Schmidtia) acwminatus humeratus Mickwirz, 1896, idem, pp. 184-186, Pl. II, figs. 43 and 44. (Described and
discussed in German as a new variety.)

Obolus (Schmadtia) acwminatus subtriangularis Mickwrrz, 1896, idem, pp. 186-187, Pl. II, figs. 45 and 46. (Described
and discussed in German as a new variety.)

The original description by Mickwitz follows:

This remarkable species comprises, as the preceding, a number of forms essentially deviating from one another
(especially in outline), whose unity can be safely asserted only by the agreement of certain characters important for
the distinction of different species of the subgenus Schmidtia. To these belong, in the first rank, the peculiarly devel-
oped beak, with the aberrantly placed indications of a pseudo-area, which stands in a certain opposition to that of
O. obtusus. The latter shows, as we have seen, this part of the shell flat, obliquely truncated, and the traces of a
pseudo-area far removed from the peduncular groove. With O. acwminatus, on the contrary, the beak is highly arched,
inwardly bent, and the traces of a pseudo-area coincide with the borders of the peduncular groove.

Diagnosis: Shells small; large shell (ventral valve) strongly arched, small shell (dorsal valve) more weakly.
Greatest height of both shells directed more toward the beak. Outline oval. Beak of the large shell high, pointed,
falling off steeply toward the tip of the beak and the umbonal borders. Tip of the beak bent inward. Anterior border

|
:
:
:

OBOLIDA. - 443

of the large shell somewhat receding from the plane of the lateral borders. Beak and anterior border of the small shell
somewhat projecting beyond the same. Shell borders thin, sharp edged, in the small shell formed like the border of
a plate. Outer surface of the shell polished, somewhat irregular because of unequally deeply cut concentric furrows,
and rough toward the front because of the projecting borders of the lamellee. Area small, in the large shell triangular;
in the small, shaped like a band. Splanchnoccelic part of the large shell reduced to the borders of the peduncular
grooves; with the small excavated into narrow furrows. Pleuroccelic parts of the large shell deeply hollowed out; in
both, at the base, posteriorly somewhat caudate, extended, and drawn out into the lateral borders. Peduncular groove
parallel-bordered, narrowing as a rule toward the apex of the shell in the excavation of the area supported by a bridge.
Traces of a pseudo-area on the large shell coinciding with the borders of the peduncular groove or running very close
to thesame; in the small shell in similar position, including between them the narrowly grooved, excavated, splanch-
noccelic part of the area surface. Shell thickening slight. Median septum under the magnifying elass mostly
perceptible, in the large shell often in connection with the bridge supporting the peduncular furrow. Lateral septa
receding. Median swelling of the small shell plainly developed, between the places of attachment of the anterior
lateral muscles in the form of a sharp ridge. Posterior part of the central depression very widely extended; anterior
part parallel-bordered, at the tip scarcely broadened.

Observations: O. acuminatus is, next to O. obtusus, the most characteristic species of the subgenus. The most
essential differences of these two species, which lie in the formation of the beak, have been referred to in the beginning.
For the rest they also differ so far from each other in the form and size of their shells that a confusion of them is pre-
vented. The external characters which separate O. acuminatus from the two other species of the subgenus Schmidtia
are less striking.

From 0. celatus the species now in question is separated externally principally through the oval outline, in the
more considerable height of their shells, whose greatest height lies more toward the beak; from O. crassus, to which it
is closely related in relation to the outline and height of the shell, through the steeper falling off of the arching toward
the tip of the beak. The shells of the last-named species have likewise an oval outline, but the relative breadth of
the same is greater. Also the arching of the shells in O. crassus is somewhat stronger in the middle, but the greatest
height lies more toward the center of the shell. The S-shaped section of the border of the large shell of O. acwminatus,
to which a slight concavity in the small shell corresponds, was also noticed in O. celatus prxcisus; but here also the
broad oval outline of the shells of this variety and the flat falling off of the arching of the tip of the beak give a certain
and distinctive external character.

The relations are shown more clearly by comparing the average characters of the respective relative numbers
than by figures and descriptions. :

The aberrant characters, which are present in the interior of the tip of the beak, are by far more important for
the distinction of the species than the external differences of form. The most characteristic among these is the position
of the traces of the pseudo-area, which in O. acwminatus run parallel and coincide with the peduncular groove; in
O. celatus and O. crassus, however, they are removed from the latter and converge posteriorly.

The form of the shells of O. acwminatus shows but slight deviations. In some specimens the highly arched beak
of the large shell, which falls off steeply posteriorly and laterally, is somewhat more sharply pointed and the tip of the
beak seems to be compressed toward the side. In others the S-shaped section of the border of the large shell is more
slightly wavy, but in the differences of form no rule can be perceived. It is similar with the small shells.

In regard to regularity, however, the outer surface of the shell seems to be subject to greater deviations than the
foregoing species in their concentric striations. Besides forms with entirely smooth and lustrous shell surfaces,
some occur that have very irregularly deep sculptured concentric furrows, which become especially irregular toward
the anterior border and give the shells a dull aspect.

The area is in both shells very unevenly striate, and in the large shells, on account of the fracture in the pedun-
cular furrow and the somewhat incurved tip of the beak, it is, as arule, slightly excavated. With normally built shells
the traces of the pseudo-area show slight inclination to separate themselves from the borders of the peduncular fur-
row; and the deviations (which some specimens pointing to the variety alatus show in this direction) are always very
small. In the small shell, whose traces of a pseudo-area lie opposite those of the large shell, these deviations show
themselves in a greater breadth of the furrow similar to the peduncular groovelike furrow which forms the splanch-
noccelic part of the area.

The crowding of the splanchnoccele into the beak of the large shell (which is conditioned by the high arching
and the uniformly slight thickening of the same) is only a more marked form of the groove-shaped excavation of the
base of the area. Shells whose beaks are more flatly arched show as a rule a more distinct thickening of the posterior
part, and, in connection therewith, an unexcavated, massive tip of the beak. Thesame is also the case with the small
shells of this species. Likewise the bridge supporting the peduncular furrow is foreshadowed in that the groovelike
hollowing out of the base of the area at the mouth of the peduncular furrow is transplanted into the splanchnoceelic part.

The inner configuration of the shells is, on account of the defective thickening, asa rule slightly pronounced. An
exception is formed by the spots of attachment of the central muscles of both shells and the median swelling of the
small shell, which are always easily perceptible. The former are shown deeply sunken in the large shell, and in the
roundish form characteristic for the Schmidtias, while the laterally situated places of attachment of the outside lateral
muscles are only slightly deepened, but are separated from those by a distinct ridge. In a small shell the places of
attachment of the central muscles appear in the form of strong protuberances. The median swelling is, in opposition
to that of O. obtusus, at its anterior border (between the places of attachment of the anterior lateral muscles) undivided,
and posteriorly united with the feeble median septum. In a large shell the latter appears as a very sharp, small ridge.

444 : CAMBRIAN BRACHIOPODA.

Of the remaining places of attachment of the muscles there are also plainly to be seen the ones lying in the neigh-
borhood of the area.in the small shell, while they are lost, in the large shell, in the border of the excavation.

The central depression in the large shell is always very shallow.

Of the circulatory system are to be distinguished only the posterior ends of the principal vascular canals, under
the magnifying glass.

The accessory vessels and the peripheral canals, on the contrary, are so feebly developed on all we observed speci-
mens that only indistinct traces are perceptible by reflected light.

ForMATION AND LOCALITY.—Upper Cambrian: Obolus sandstone at the following localities: (895)« at Joa, near
Jegelecht, 12 miles (19.3 km.) east of Reval; (395a) at Tihala, near Jegelecht; (395b) at Ilgast; (895¢) at Asserien, 75
miles (121 km.) east of Reval; (895d) at Ontika, about 95 miles (153 km.) east of Reval and 30 miles (48 km.) west
of Narwa; and (895e) at Isenhof, 85 miles (137 km.) east of Reval; all |[Mickwitz, 1896, p. 183] in the Government of
Esthonia, Russia.

OxpoLus (SCHMIDTIA) CELATUS (Volborth).
Plate XIV, figures 1, la-c.

Ungula ovata PanpeER, 1830, Beitrage zur Geognosie des russischen Reiches, p. 59, Pl. XXVIII, fig. 6a-b (not
Pl. III, fig. 23, referred to Obolus apollinis). (Characterized in German.)

Schmidtiacelata VoLBortH, 1869, Verband]. Russ.-kais. min. Gesell. St. Petersburg, 2d ser., Bd. 4, pp. 209-212, Pl. XVII,
fies. 1-6. (Described and discussed in German as a new species.)

Schmidtia celata Volborth, Haut and CLarxKe, 1892, Hleventh Ann. Rept. State Geologist New York for 1891, p. 244,
figs. 248 and 249. (Notextreference. Figs. 248 and 249 are copied from Volborth [1869, Pl. XVII, figs. 1 and 4,
respectively].)

Schmidtia celata Volborth, Hatt and CiarKe, 1892, Forty-fiith Ann. Rept. New York State Museum for 1891, p. 560,
figs. 248 and 249. (Copy of preceding reference.)

Schmidtia celata Volborth, Hatt and CiarKe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, p. 83, figs. 37 and
38. (No text reference. Figs. 37 and 38 are copied from the figures given in the two preceding references,)i

Obolus (Schmidtia) celatus (Volborth), Mickwrrz, 1896, Mém. Acad. imp. sci. St.-Pétersbourg, 8th ser., vol. 4, No. 2,
pp. 159-163, Pl. II, figs. 19 and 20. (Described and discussed in German; see below for translation.)

Obolus (Schmidtia) celatus orbiculatus Mrcxwirz, 1896, idem, pp. 163-165, Pl. JI, figs. 21 and 22. (Described and dis-
cussed in German as a new variety.)

Obolus (Schmidtia) celatus precisus Mrckwirz, 1896, idem, pp. 166-167, Pl. II, figs. 37 and 38. (Described and discussed
in German as a new variety.)

Obolus (Lingulella) celatus (Volborth), Waxcorr, 1898, Proc. U. S. Nat. Mus., vol. 21, Pl. XXVI, figs. land 2. (No
text reference. The specimens represented by figs. 1 and 2 are redrawn in this monograph, Pl. XIV, figs. la
and 1c, respectively.)

Obolus celatus orbiculatus (Mickwitz), Wmtan, 1902, Bull. Geol. Inst. Univ. Upsala, vol. 6, pt. 1, No. 11, p. 62. (New
locality mentioned in German.)

Obolus celatus orbiculatus (Mickwitz), Mopere and SrcrrBerG, 1906, Medd. fran Lunds Geol. Faltklubb, Ser. B,
No. 2 (Aftryek ur K. Fysiografiska Sallskapets Handl., N. F., Bd. 17), p. 65. (Mentions locality given in pre-
ceding reference, in Swedish.)

Obolus celatus orbiculatus (Mickwitz), WrestercArp, 1909, Medd. fran Lunds Geol. Faltklubb, Ser. B, No. 4 (Aftryck
ur K. Fysiografiska Sillskapets Handl., N. F., Bd. 20), p. 56. (Locality mentioned in Swedish.)

The original description by Mickwitz follows:

This species was first described by Volborth, who also gave us the first knowledge of a part of the places of attach-
ment of the muscles. The first figure of a small shell is, however, found in Pander’s above-cited work as Ungula ovata;
but this drawing lacks all internal characters with exception of the plate-shaped border of the shell, which Volborth alse
mentions. Much more exact drawings of a whole series of Schmidtias (without names or description) are preserved
to us in a sheet among the papers left by Pander, which was kindly handed over tome by Professor Lahusen. The places
of attachment of the muscles, especially of the small shells, are in some of these figures present in full proportion,
but, to besure, not disentangled as their individual constituent parts. Also on one specimen of a large shell are plainly
designated the principal and accessory vessels (which radiate inwardly). I have not utilized these drawings in any
present work, because my material is much more complete than that of Pander, and, moreover, the species described
by me could not with sufficient certainty be identified with the drawings in question.

Diagnosis: Shells small, slightly arched; arching of the small shell slighter than that of the large shell. Outline
of the shells roundish, umbonal border of the large shell rectilinear. Surface of shell very smooth and lustrous; con-
centric striation very fine, in thickness somewhat irregular. Anterior (Stirn) and lateral borders thin, sharp margined:
those in the small shell usually somewhat thickened, with the umbonal borders lying in one plane. Area small, in
the large shell slightly interrupted in the peduncular furrow; in the small shell, in the splanchnoceelic part, deepened

a Locality 395 is represented in the collections of the United States National Museum.

OBOLID. 445

into a depression; peduncular furrow shallow but plainly developed, slightly diminished toward the tip of the beak.
Traces of a pseudo-area bent slightly concave to the area lamelle at the median line of shell, converging into the
tip of the beak. Shells almost uniformly thick, toward the beak only a little thickened. Traces of the principal
vessels broad, shallow, little prominent; middleswelling and lateral furrows of thesamescarcely projecting. Secondary,
inwardly radiating vessel traces in the large shell in the principal direction perpendicular to the principal vessels;
in the small one curved anteriorly, in both very indistinctly ramified. Central groove of large shell pestle-shaped,
with a slight swell. Apex of central groove relatively broad, somewhat drawn out, parallel-bordered, generally some-
what involved with the combined central places of attachment of the muscles. Median swelling of small shell dis-
tinctly developed, growing over into the median septum, at times separated by a fine median groove. Corneous
processes and sinus receding very much.

Observations: 0. celatus varies as all Obolus species in its external form and internal configuration of its shells.
The want of space, however, forbade the illustration of these alterations in a manner similar to that used for the prin-
cipal species of Hichwald’s genus. I had to restrict myself to the illustration of the extreme members of the series of
forms. This remark concerns all species of the subgenus Schmidtia.

Aside from the form figured by Volborth, some with circular outline and others with flattened anterior border
occur, which are connected with the principal forms by transitions and were demonstrated in their extreme members
as O. celatus orbiculatus and O. celatus precisus. To all members of this group, brought together as O. celatus, a note-
worthy peculiarity of accessory nature is common which is lacking in the remaining species of the subgenus Schmidtia,
and which, therefore, may be looked upon as a further argument for the cospecificity of the forms mentioned. This
peculiarity is a fine netlike coating, which may be found on many of these shells and which often covers the surface
of the shell in several superimposed layers in the form of crusts. It may indicate the existence of a bryozoan.
Traces of the netlike coating are, however, also found in the specimens of the variety pracisus.

The tip of the beak and the anterior border of the large shell deviate in some specimens from the normal character
in such a manner that both recede somewhat from the level of the border of the shell; then in the corresponding small
shell the reverse occurs so that the closing of the shell is secured. The receding of the beak is nevertheless never so
strong as, for example, in O. obtusus. The flat plate-shaped border [Volborth, 1869, p. 210] of the small shell is formed
by the last separated lamella of the border, which is marked off from the remaining surface by the principal vessel
furrows which course along its inner border, and, in consequence of the flatness of the small shell, it stands out more
distinctly. In the large shell the principal vessel furrows are moved more toward the interior of the splanchnoccele,
and as the shell also has a stronger arching, the lamellee of the border recede farther. Besides, this formation, which
is found in all species of the subgenus Schmidtia, is very variable in its strength and in some small shells hardly
perceptible. On the other hand, it at times also occurs in the large shells in which the peripheral canals play the same
part as the principal vessel furrows. :

The surface of the area of the large shell in this species of the subgenus Schmidtia is least broken in the peduncular
furrow, and the area itself reminds one of that of the typical species, especially in that the traces of the pseudo-area
of the area lamellz converge into the tip of the beak. The pleuroccelic parts of the area of both shells are only
slightly prolonged into the lateral borders. On the other hand, the area of the small shell deviates from that of O.
apollinis by the deepening of its splanchnoceelic part, which possesses in consequence of the special position of the
traces of the pseudo-area in this species a subtriangular form.

The form of the central groove varies within rather wide limits. Through lateral restraint of the posterior part of
the protruded parallel-bordered tip there results an irregular biscuit-shaped outline, and through compression of the
posterior broad part of the central groove in the median direction, a simultaneous shortening and tapering of the anterior
part. Some shells show the protruded tip laterally compressed, so that only a narrow groove is left, which is then as a
rule inclosed by strong swellings. In others this groove possesses a breadth which almost equals the posterior part of
the central groove. All these alterations of form, which seem subject to no law, are also peculiar to all other species
of the subgenus.

The side septa and median septum are, even if slightly, developed in both shells. The former as a rule stand
out more distinctly in the large shells; the latter, however, in the small ones, where it is more distinctly expressed,
appears as a prolongation of the always strongly pronounced median swelling.

The corneous processes and the sinus of the small shell are rarely to be distinguished. Yet in some specimens,
in reflected light under a lens, two fine ridges are seen, which converge from the external sides of the places of attach-
ment of the central muscles toward the beak and, with the median swelling, form a triradiate figure.

In spite of their minuteness the places of attachment usually stand out distinctly, especially those of the central
muscles, which in both shells as a rule are let down deeply with swelled borders. Also the separation of the combined
places of attachment is attained with the help of a lens, although naturally with more difficulty than in the larger forms
of Hichwald’sgenus. Itis very difficult to perceive the places of attachment of the transmedian and the combined places
of attachment of the outside and middle lateral muscles in the small shells. The places of attachment of the central
muscles, as also those of the outside and middle lateral muscles of the large shell, have more roundish forms and are
not so closely connected as in the species of the subgenus Huobolus. Noteworthy is also the somewhat deviating
position of the places of attachment of the central and anterior lateral muscles in the small shell.

The direction of the longitudinal axes converge, in the former toward the beak, in the latter toward the anterior
border. As these places of attachment have in by far the most cases a pronounced elongate form, this position is very
striking and was also noticed by former observers [Volborth, 1869, p. 210].

446 CAMBRIAN BRACHIOPODA.

Little is to be said of the vessels. It is the easiest, especially in the small shells, to distinguish the peripheral
canals, which lie on the plate-shaped border and are usually perceptible under the ils Tt is more difficult to per-
ceive the principal vessels. They easily lose themselves in the small shell in the terrace of the plate-shaped border
and are but seldom perceptible in the large shell in spite of their freer position.

The lateral vessels sink in their minuteness to microscopic sizes and are distinguishable only in exceptional cases
by use of strong enlargement. This is particularly the case in the ramifications, which are very indefinite in this
species. The figured specimens allow the vessel system to be perceived very faintly under the lens.

As arule the parietal band is seen, and it is also faintly suggested in the figures. In the small shell it also stands

out on account of the fine-grained character of the splanchnoceelic part of the shell.

ForMATION AND LOCALITY.2—Upper Cambrian: Obolus sandstone at the following localities: (395) At Joa, near
Jegelecht, 12. miles (19.3 km.) east of Reval; (395a) at Tihala, near Jegelecht; (395b) at Ilgast; (395c) at Asserien, 75
miles (121 km.) east of Reval; (395d) at Ontika, about 95 miles (153 km.) east of Reval and 30 miles (48 km.) west
of Narwa; and (395e) at Isenhof, 85 miles (137 km.) east of Reval; all in the Government of Bsthonia, Russia.

Obolus conglomerate at the following localities: (895g) At Joa, near Jegelecht, 12 miles (19.3 km.) east: of Reval;
(395h) at Tihala; (395i) at Ilgast; (395j) at Asserien, 75 miles (121 km.) east of Reval; (395k) at Ontika, about 95 miles
(153 km.) east of Reval and 30 miles (48 km.) west of Narwa; (3951) at Isenhof, 85 miles (137 km.) east of Reval; all in
the Government of Esthonia, Russia.

Sandstone below the Obolus conglomerate at the following localities: (395m) At Joa, near Jegelecht, 12 miles
{19.3 km.) east of Reval; (395n) at Tihala; (3950) at Ilgast; (8395p) at Asserien, 75 miles (121 km.) east of Reval; (395q)
at Ontika, about 95 miles (153 km.) east of Reval and 30 miles (48 km.) west of Narwa; and (395r) at Isenhoi, 85 miles
(137 km.) east of Reval; all in the Government of Esthonia, Russia.

(3360) Ungulite grit at Koporje, Government of St. Petersburg; and (336p) Ungulite grit at Kunitz, Government
of Pskow; both in Russia.

Schmidtia conglomerate (part of the Obolus conglomerate) at the following localities: (395s) At Asserien, 75 miles
(121 km.) east of Reval; (395t) at Ontika, about 95 miles (153 km.) east of Reval and 30 miles (48 km.) west of Narwa;
and (395u) at Isenhof, 85 miles (137 km.) east of Reval; all in the Government of Esthonia, Russia.

(321d) Drift bowlder of Obolus sandstone, No. 21 [Wiman, 1902, p. 68], on Fanton Island, parish of Borstil,
Province of Stockholm, Sweden.

Oxsoius (ScumiIpTIA) crassus Mickwitz.
Plate XIV, figures 4, 4a-d.

Obolus (Schmidtia) crassus Mickwirz, 1896, Mém. Acad. imp. sci. St.-Pétersbourg, 8th ser., vol. 4, No. 2, pp. 187-193,
Pl. Il, figs. 47-49, 52-55. (Described and discussed in German as a new species; see below ior translation.)

Obolus (Schmidtia) crassus angulatus Mickwrrz, 1896, idem, pp. 193-194, Pl. II, figs. 50 and 51. (Described and
discussed in German as a new variety.)

The original description by Mickwitz follows:

Obolus crassus is the most abundant species of the subgenus Schmidtia. Its shells are massively built and to this
circumstance we are indebted for the remarkably strong development of all the internal characters, a development.
which has been of the greatest importance in rendering possible the determination of the organization of the genus
Obolus Eichwald. With the large choice of well-preserved shells, specimens are found which preserve the finest detail,
as, for example, the outwardly and inwardly radiating accessory vessels, the opening of the principal vessels of the
large shell into the peripheral canal, ete. This development of the inner characters, standing alone among all the
Obolus species, which, so to speak, forms the basis of the anatomical part of the present work, and in many doubtful
cases has proved decisive, was the cause of directing to the shells of O. crassus especial attention, which finds expression.
in the increased number of figures and measurements.

Diagnosis: Shells small, thick. Large shell (ventral valve) strongly arched, small shell (dorsal valve) less so.
Outline of shells broadly oval, umbonal borders convex. Surface of the shell faintly polished; concentric striation
rather fine, not uniform. Growth lamellz bordered by quite deeply engraved lines, toward the anterior border nob
strongly projecting. Shell borders massive, blunt; plate-border formation slightly developed. Anterior border
and tip of the beak of the large shell mostly weeding a little from the plane of the lateral border; in the small shell
projecting. Area yery large, triangular, unevenly striate. In the large shell somewhat broken in the peduncular
groove; in the small one slightly deepened in the splanchnoceelic part; in both slightly excavated into furrows at the
almost rectilinear base. Peduncular groove deeply cut, narrowing slightly toward the tip of the beak. Traces of
the pseudo-area strongly developed, rectilinear, more or less converging posteriorly, separating the lateral borders.

Thickening of the shell quite regular, somewhat stronger at the splanchnoccelic part. Septa of both hardly per-
ceptible. Corneous processes of the small shell suppressed by the strongly developed median swelling, which includes
the entire protruded splanchnoccele and fills the sinus. The median swelling has a fine median furrow at the anterior
border. Central groove of the large shell as a rule deeply sunken and bordered by swellings. Posterior part very
broad, anterior projecting tip parallel-bordered.

a Locality 395 is represented in the collections of the United States National Museum; the remaining localities are taken from the references.
given in the synonymy. The authority for each locality cited is given in the list of localities, pp. 161-291.

a

—

OBOLIDA. 447

Principal vessel furrows broad and flat. Central swelling of same slightly pronounced. . Central swelling of the
peripheral canals mostly separated into square sections by furrows which are parallel, directed obliquely outward,
and which subside posteriorly. Secondary inwardly radiating vessel furrows strongly and irregularly branched; in
the large shell perpendicular in their principal direction to the principal vascular canals; the posterior ones running
out into the interior of the brachioccele, those more anteriorly placed bending toward the peripheral canal and
opening into the same. In the small shell these furrows take an oblique direction, anteriorly and internally from
the lateral parts of the principal vascular canals but posteriorly and externally from the parts turned off toward the
places of attachment of the anterior lateral muscles. Secondary outwardly radiating vascular traces in both shells
rectilinear, perpendicular to the principal vascular furrows, plainly forked, close before the opening into the
peripheral canal.

Places of attachment of the muscles in both shells strongly sunken, those of the central and outside lateral muscles
of the large shell oval, somewhat separated from one another by a small swelling.

Parietal band in both shells plainly developed, normally running out, brought out through the fine-grained condi-
tion of the surface.

Observations: O. crassus reminds one, in the form of its shell, of O. acwminatus in relation to the position of the
traces of the pseudo-area; it takes, on the contrary, an intermediate position between QO. celatus and O. obtusus. The
relations to O. acuminatus have already been mentioned (p. 443). Further, at the same place it was pointed out
that the traces of the pseudo-area of both species (O. crassus and O. celatus) converge posteriorly. The difference in
the position of the converging pseudo-areas of the two last-named species is, however, very essential and consists in the
fact that in O. celatws the same opens into the tip of the beak; with O. crassus, on the contrary, the borders of the area
intersect at a certain distance from the beak. The last can, under some circumstances, become so large that the traces
of the pseudo-area maintain a subparallel position which reminds one of that in O. obtusus. A confounding of the two
species in this rarely occurring case is meanwhile excluded on account of the high triangular area and the deviating
form of the shell of O. crassus. In a majority of the shells the convergence of the traces of the pseudo-area is dis-
tinctly pronounced. :

The high, coarsely striate area hasa plump form in consequence of the pleuroceelic part being only slightly drawn out
into the lateral borders, and on account of its convex external borders, which contrast strongly with those of O. celatus. Its
base runs almost straight, is always composed, in common with the other species of the genus Obolus, of three shallow
curves, and is slightly grooved; tip in the large shell usually recedes somewhat from the plane of the shell borders.
The break in the surface of the area in the large shell, in the peduncular, is insignificant but somewhat stronger than
in O. celatus; the sunken splanchnoccelic part of the area in the small shell has a trapezoidal form, in consequence of
the special position of the traces of the pseudo-area, and is somewhat hollowed out in the median direction. * * *

The profile of the shell borders shows in both shells, as a rule, a straight line; in the small shell it is at times
slightly bowed concavely. The shell borders themselves are, corresponding to the thick condition of the shells of
this species, thicker and less sharp than with the other species of the subgenus Schmidtia.

The external surface of the shell possesses a rather coarse concentric striation, which becomes somewhat stronger
toward the anterior border, but does not stand out in the projecting intricate form as observed in other species of
the subgenus.

The character of the internal surface of the shell offers in general the same picture which we have learned to know
in O. celatus. With the majority of the shells the central pit has the normal, pestle-shaped form, and is inclosed by
a more or less pronounced swelling. One specimen shows the latter at the posterior border and on the sides of the
depression swollen up. With another specimen it is, on the contrary, entirely absent and the central depression appears
shallowed and indefinitely bordered. This shell is in a somewhat abnormal condition. It shows in profile an arrest
of growth through which the greatest height is shoved toward the beak. At the same time it shows the places of
attachment of the central muscles as thick protuberances—especially on the right side. The septa of both shells are
very weakly developed, likewise the corneous processes of the small shell, which, as with all Schmidtias, recede before
the powerfully developed median swelling. The latter is in its anterior half provided with a fine median groove.

In reference to the places of attachment of the muscles of O. crassus there is nothing essential to be added to the
condition found in the other Schmidtias. They are found here in exactly the same position and condition as in the
other species of the subgenus, so far as the modified form of the shells does not condition slight alterations. It is at
all events to be insisted upon that these characters in the present species are found in a condition of distinctness, which
the remaining species of the subgenus do not show in equal degree.

Into the circulatory system of O. crassus, on the contrary—which, through its prominent development and preser-
vation, explains many conditions which, in the other species, must remain undecided—I shall enter more closely.

The principal vessels of the large shell of this species are moved somewhat nearer to the median line than in O.
celatus and at times acquire asubparallel position. This character, nevertheless, is extremely variable and is dependent
on the form of outline of the shell. Broader forms show these traces more approximated to the border of the shell.
In the small shell the principal vessel furrows run in the manner known near the border of the shell and parallel to
the same. The opening of the principal vascular canals of the large shell into the peripheral canal is plainly to be
seen under a lens by reflected light. * * *

The peripheral canals show a peculiar formation, which hitherto has not been noticed in the other species of the
subgenus Schmidtia. The median swelling of the peripheral canals (especially at its posterior parts) is separated by
short, obliquely placed cross furrows, which anteriorly run inward, posteriorly outward, into a series of small square
sections, which as a whole resemble a twisted ribbon. This character is somewhat inconstant and seems to appear

448 CAMBRIAN BRACHIOPODA.

only in those shells whose characters, upon the whole, are strongly pronounced. It is selfevident that such fine
particularities are only perceptible by strong magnification in reflected light; they could not be distinctly reproduced
without impairing the value of the figures.

The secondary vessels, which radiate inwardly, vary essentially both in their course and in the manner of their
ramification. In the large shell, as a rule, they ramify rectilinearly and perpendicularly to the principal vessels and
throw off short branches to both sides; only those which lie more anteriorly curve toward the anterior border and
open between the principal vascular furrows into the peripheral canal.

The accessory vessels run out entirely different in another specimen. Here they fork shortly after branching off
from the principal vessels and take their course to the posterior part of the shell. Nothing is to be seen of an opening
into the peripheral canal of the anterior border. Lastly, another shell, where these organs leave the most indistinct
traces, shows an irregular confusion of treelike ramified canals, the directions of which seem to alter by every turning
of the shell under the lens.

The accessory vessels of the small shell, which radiate inwardly, show similar differences. Asarule, the accessory
vessels issuing from the central part of the principal vessels, turn anteriorly immediately after their exit from the
latter, and are slightly curved in the shape of an S and hardly ramified. Only those lying at the extreme back bend
into the angular spaces of the brachioccele, which are tormed by the parietal band; the accessory vessels, however,
which ramify from the anterior, inwardly bent ends of the principal vessels, run rectilinearly posteriorly. Another
specimen, however, shows the central accessory vessels directed more posteriorly and very strongly ramified.

What significance these essential deviations have in the systematic aspect can not, however, be established at
present. No correlation has hitherto been obtained. .

The secondary outwardly radiating vascular traces correspond, in all examined specimens, in regard to their
arrangement and course. Branching off perpendicularly to the principal vessels, the straight, short traces fork before
opening into the peripheral canal.

As in O. celatus, the parietal band may be followed as a fine furrowed swelling, and where perceptible traces are
lacking it is often established through the difference in the character of the surface of the splanchnoccele and
brachioceele.

This form owes its specific name to the massiveness of its shells.

FORMATION AND LOCALITY.2—Upper Cambrian: Obolus sandstone at the following localities: (395) At Joa, near
Jegelecht, 12 miles (19.3 km.) east of Reval; (395a) at Tihala, near Jegelecht; (395b) at Ilgast; (895¢c) at Asserien,
75 miles (121 km.) east of Reval; (395d) at Ontika, about 95 miles (153 km.) east of Reval and 30 miles (48 km.)
west of Narwa; and (395e) at Isenhof, 85 miles (137 km.) east of Reval; all [Mickwitz, 1896, p. 192] in the Government
of Esthonia, Russia.

Osotus (ScHmMipTIA) oBTUSUS Mickwitz.

Plate XIV, figures 3, 3a-c.

Obolus (Schmidtia) obtusus Mickwrrz, 1896, Mém. Acad. imp. sci. St.-Pétersbourg, 8th ser., vol. 4, No. 2, pp. 167-171,
Pl. II, figs. 23, 24, 33, and 34. (Described and discussed in German as a new species; see below for translation.)

Obolus (Schmidtia) obtusus longus Mickwirz, 1896, idem, pp. 171-172, Pl. II, fig. 25. (Described and discussed in
German as new variety. )

Obolus (Schmidtia) obtusus acutus Mickwirz, 1896, idem, pp. 172-173, Pl. II, fig. 26. (Described and discussed in
German as a new variety.)

Obolus (Schmidtia) obtusus latus Mickwirz, 1896, idem, pp. 174-175, Pl. II, fig. 27. (Described and discussed in Ger-
man as a new variety.) :

Obolus (Schmidtia) obtusus minutus Mickwrrz, 1896, idem, pp. 175-177, Pl. II, figs. 29and 30. (Described and discussed
in German as a new variety. )

Obolus (Schmidtia) obtusus ellipticus Mrcxwirz, 1896, idem, pp. 177-178, Pl. II, figs. 31 and 32. (Described and dis-
cussed in German as a new variety.)

Obolus (Schmidtia) obtusus extenuatus Mickwirz, 1896, idem, pp. 178-179, Pl. II, figs. 35 and 36. (Described and dis-
cussed in German as a new variety.)

Obolus obtusus (Mickwitz)?, Wm1an, 1902, Bull. Geol. Inst. Univ. Upsala, Bd. 6, pt. 1, No. 11, p. 63, Pl. III, fig. 12.
(New locality mentioned in German.) '

Obolus obtusus (Mickwitz)?, Mopere and SecerBere, 1906, Medd. fran Lunds Geol. Faltklubb, Ser. B, No. 2 (Aftryck
ur K. Fysioerafiska Sallskapets Handl., N. F., Bd. 17), p. 65. (Locality mentioned in Swedish.)

Obolus obtusus (Mickwitz)?, WesterGArp, 1909, Medd. fran Lunds Geol. Faltklubb, Ser. B, No. 4 (Aftryck ur K.
Fysiografiska Sillskapets Handl., N. F., Bd. 20), p. 57. (Locality mentioned in Swedish.)

The original description by Mickwitz follows:

This extraordinary species, whose principal characteristics consist in the peculiar character of the area which is
predominantly prolonged, consists of a large number ot shells, which do not essentially deviate in outline and size.
All of these forms are rare; of some of them only one was found; in consequence, their cospecificity could not be proven

a Locality 395 is represented in the United States National Museum collections.

|

OBOLIDA. 449

in all cases through transitions. I was for a long time undecided as to whether I should refer all of these aberrant
shells to one species. Nevertheless, the fact that deviations in a much greater measure are not extraordinary in other
Obolus species, and, furthermore, the fear of multiplying the number of species without decisive reason, and, lastly,
the correspondence of the different forms in the mentioned principal characters persuaded me to look upon the entire
group as belonging to one species. The characteristic form was erected into a species and the others were subordinated
to it as varieties. However, it is possible that with more complete material the one or the other variety will be removed
from the species. At present this arrangement will make easy the general view of the forms.

Diagnosis: Shells moderately large, flatly arched, drawn out lengthwise. Outline subtriangular. Tip of beak
of the large shell somewhat protruded, obtuse-angled, externally obliquely truncated; small shell almost rectilinearly
cut off. Borders of the beak of the large shell receding from the plane of shell borders, going over into the lateral
borders with a roundish angle. Exterior surface of shell very smooth, strongly lustrous like varnish, concentric strize
very fine. Growth lamellz marked by somewhat coarser grooves, commonly standing out at the anterior border like
shingles. Area large, splanchnoccelic part broad, band-shaped; pleuroccelic part prolonged far into the lateral bor-
ders. Plane of the area of the large shells broken in the peduncular groove, in the small shell depressed into broad
grooves between the traces of the pseudo-area. ‘Traces of the pseudo-area parallel in both shells very near to borders of
area. Peduncular groove broad, flat, parallel bordered. Thickening of shell slight, inner configuration slightly pro-
nounced. Central depression of large shell pestle-shaped, at times indefinitely flattened. Septa and corneous proc-
esses receding very much. Median swelling of small shell strongly developed, divided by a sharp furrow between
the places of attachment of the anterior lateral muscles. Places of attachment of the muscles distinctly pronounced.
Those of the outside lateral muscles of large shell circular, standing off from those of the central muscles and mostly
separated by a roundish swelling.

Observations: The few shells of this relatively rare species which are at hand in finest preservation do not allow
some necessary characters of the visceral surface to be distinguished. Especially the impressions of the lateral vessels
are withdrawn from observation, although just these characters, through their wonderful development and preserva-
tion in some species of the subgenus Schmidtia (e. g., in O. celatus and O. crassus), make possible in the highest degree
the study of the vascular system in Eichwald’s genus. Yet, in spite of the incomplete characterization, O. obtusus
belongs to the best-defined species of the subgenus Schmidtia.

The peculiarity shows itself for the first in the predominant prolongation and the slight arching, which find their
numerical expression in the respective value of b:landh:1. These relative numbers are in O. obtusus smaller than in
all other species of the subgenus. * * * :

To the longitudinally extended form now comes the broad obtuse-angled tip of the beak, which gives the shells a
subrectangular outline, and by which O. obtusus is distinguished as well from all other species of the subgenus Schmidtia
as from those of the other subgenera. The tip of the beak of a large shell loses its blunt form, and the rounded angle
of the posterior border of the shell disappears, so that the outline becomes more broadly oval. In similar manner
the small shell is changed. The corners of the blunted tip of the beak become round, and the rectilinearly truncate
tip of the beak assumes a slightly convex form.

Of less specific account than the form, but not less striking to the eye, is the more considerable size of the shells,
which surpasses that of all other species of the subgenus Schmidtia, the average length of the large shell being 6.47
mm., while the corresponding valve of the next largest species (O. crassus) only attains 5.96 mm. These results refer
to the species with the exception of the varieties; of the latter, O. obtwsus longus has a still more considerable length
(7.7 mm.).

The exterior surface of the shell of a specimen figured shows some short, radially placed, slight furrows on the
central part of the surface; the furrows are lacking on the posterior borders. This striation can, however, only be looked
upon as an occasional formation, for, even if slight furrows of the same kind can be noticed in another specimen, they
are entirely missing in all other shells examined. Isolated striz of this kind also occur in the other Schmidtias.

The formation of the area is very aberrant. While this part of the shell is generally triangular in the other species,
it assumes in O. obtusus the form of a broad band, which hems the tip of the beak and is prolonged far into the borders
of the shell. The splanchnoccelic part of the base of the area runs parallel to the borders of the beak and is, corre-
sponding to the tip of the beak, angled in the peduncular furrow. In thesmall one itis rectilinear or slightly concave.

The surface of the area of the large shell sinks, as in O. celatus, only in a far stronger degree, from both sides toward
the peduncular groove; besides this the whole surface of the area inclines obliquely toward the exterior, so that the
borders of the beak recede from the surface of the border of the shell. The gap of the surface of the area in the pedun-
cular groove is partly a consequence of the deficient thickening of the posterior part of the shell, which causes the lamellee
of the area to appear as a mere covering of the hollow tip of the beak; yet it is partly brought about by a slight lateral
compression of the tip of the beak, which is also indicated at the exterior surface of the shell through a slight roundish
median edge perceptible in reflected light. In the small shell these conditions occur in a similar manner, but stand
out less distinctly.

Especially characteristic for this species is the position of the traces of the pseudo-area, which run parallel to the
median line of the shell and are very near the lateral borders of the area. In some the posterior part of these traces
seems to bend toward the tip of the beak with aroundish angle. Yet in nature the traces of the pseudo-area run recti-
linearly to the posterior border of the beak and the deflecting apparent prolongations of the same are only accidental
examples of more stronely sculptured strie of the area.

62667°—vo1 51, pr 1—12—_29

450 CAMBRIAN BRACHIOPODA.

This position of the traces of the area, which is far removed from the peduncular groove, appears to point to the
relative size of the embryonal shells—a conjecture to which the consideration of the broad, parallel-bordered peduncular
eroove of O. obtusus has already led. In the small shell, the traces of the pseudo-area run exactly in the same man-
ner, and inclose the flatly deepened splanchnoccelic part of the area between them, which allows a shallow, rather
broad groove in the median line, opposite the peduncular groove of the large shell, to be perceptible by reflected
light.

The thickening of the shells is generally very slight, and therefore the configuration of the inner surface stands
out but little. Nevertheless, predominant fluctuations occur also in this species. It is noteworthy that of all the
formations which stand out from the surface of the shell, the median swelling of the small shell is the most given
to variations, which often degenerate in a monstrous manner. * * * The heart-shaped groove is given to
similar alterations of form as we have learned in O. celatus, and may be partly dependent on the strength of the
thickening * * *.

The places of attachment of the muscles are in general distinctly pronounced, but not so sharply bordered as with
the large forms of Hichwald’s genus. Especially there are here also, as with O. celatus, the large central spots of attach-
ment of the large shell, only with difficulty decomposable into their constituent parts. As with the previous species,
the outside lateral muscles are delimited from the central muscles and form, close to the principal vascular canals,
isolated, shallow-pitted, excavated places of attachment.

Of the principal vascular canals there can be distinguished on all the specimens at hand, in both shells, only the
posterior parts; in the small shells, besides, as a rule, also the ends, curved around posteriorly and directed toward the
places of attachment of the anterior lateral muscles. The first are very broad, flat, and divided by a median swelling,
which often appears to be a prolongation of the lateral septa. ‘The latter in no way deviates from the usual arrange-
ment. Of the accessory vascular canals there can be observed only slight indications of the inwardly radiating canals,
which show as somewhat lighter colored lines.

FoRMATION AND LOCALITY.2—Upper Cambrian: Obolus sandstone at the following localities: (895) At Joa, near
Jegelecht, 12 miles (19.8 km.) east of Reval; and (895b) at Ilgast; both [Mickwitz, 1896, p. 171] in the Government
of Esthonia, Russia.

(321¢ [Wiman, 1902, p. 68]) Drift bowlder of Obolus sandstone, No. 17, on Fanton Island, parish of Borstil,
Province of Stockholm, Sweden. :

WESTONIA Walcott,> subgenus of OBOLUS.

Obolus ( Westonia) Waxtcott, 1901, Proc. U.S. Nat. Mus., vol. 23, pp. 683 and 691. (Described on latter page, as below,
as a new subgenus.)

(Westonia) Walcott, Marruzw, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, pp. 205-206. (Copies
original description, and discusses the form as a subgenus more allied to Lingulella than Obolus.)

Lingulella Grasau and Suimer [not Satter], 1907, North American Index Fossils, vol. 1, p. 192. (Described as
Lingulella, but both species that are referred to it belong with Obolus ( Westonia).)

Obolus (Westonia) Waucort, 1908, Smithsonian Misc. Coll., vol. 53, No. 4, Pl. XI, and pp. 142 and 144. (Classification
of genus.)

Ovate, with ventral valve slightly acuminate; area of ventral valve strongly defined and
divided by a relatively large pedicle groove. Surface marked by concentric and radiating
strie that are crossed by transverse, semi-imbricating, ‘‘ripple-embossed” lines. So far as
known, the muscle scars and vascular markings are essentially the same as in Obolus.

Type.—Lingula aurora Hall.

Of the species referred to Westonia, Obolus ( Westonia) aurora (Hall), O. (W.) ella (Hall and
Whitfield), O. (W.) euglyphus (Walcott), O. (W.) chwarensis (Walcott), O. (W.) stoneanus

a Locality 395 is represented in the United States National Museum collections.

b The synonymy for this subgenus does not give a complete record of the various genera under which the species now included in Westonia
were formerly placed; it gives only those references in which the genus is discussed or described. To complete the record the following mere generic
references are listed:

Lingula Hall [1861, p. 24].

DLingula Rogers [1861, p. 390; 1862, p. 4; 1863, pp.
126 and 127; 1867, pp. 103 and 104).

DLingulella Hall [1873, p. 244].

Lingulepis Hall and Whitfield [1877, p. 232].

Lingula Barrande [1879b, Pls. CVI and CX]J].

Lingulella Whitfield [1882, p. 344].

Lingulella Walcott [1886b, p. 97; 1891a, p. 607].

Lingulella Hall and Clarke [1892c, p. 58 and PI. II,
figs. 9-11 and 12-13].

Lingula Sardeson [1896, p..95].

Lingulepis Walcott [1897a, p. 404).

Obolus (Lingulella) Walcott [1898b, pp. 399, 402,
and 413, and Pl. XXVIII).

Lingulella Grahau [1900, p. 624].

Lingulella ? Matthew [1901a, p. 270).

Lingula Wiman [1902, p. 51).

Lingulella ? Wiman [1902, p. 52).

Obolus Matthew [1902e, pp. 96 and 110).

Obolus (Westonia) Walcott [1902, p. 611).

Lingulella Weller [1903, p. 112).

Obolus (Westonia) Walcott [1905a, pp. 334, 335, 336,
and 337].

Lingulella Pack [1906, p. 295).

Lingulella (Westonia) Grabau and Shimer [1907,
p. 193].

Obolus (Westonia) Walcott [1908d, pp. 67, 68, and 69].

OBOLIDA. 451

(Whitfield), O. (W.) rogersi (Walcott), O. (W.2) lamellosus (Barrande), and O. (W.) escasoni
(Matthew) all have transverse, irregular, elevated lines. In O. (W.) stoneanus and O. (W.)
rogersi these lines have two or three sharp undulations near the median line, and in O. (W.)
aurora many short and more or less irregular undulations occur on the entire central portion of
the shell. Beyond the short, central undulations, more or less wave-like, long undulations extend
to the sides of the valve, usually with a slight backward curvature toward the margin.

Obolus (Westonia) finlandensis Walcott, O. (W.) bottnicus (Wiman), and O. (W.) wimani
Walcott, of the Middle (possibly Lower) Cambrian sandstones of Sweden, differ in surface
characters from the typical species of the genus. In these species the concentric lines and striz
of growth are well marked, also radiating lines that extend from the umbo irregularly toward
the front and side margins of the shell. In addition there is a series of somewhat irregular
striz or lines that terminate at right angles to the lateral margin, start in toward the center of
the shell, and then curve backward so as to meet at the center, or merge apparently into the
radiating strie (Pl. XLVIII, figs. 3 and 3a). These lines were apparently formed by the same
agency (the front margin of the mantle) that formed the various irregular, more or less trans-
verse lines on the other species of the genus. The two other species from the sandstones of
Sweden, O. (W.) adlandensis Walcott and O. (W.) balticus Walcott, appear to have the typical
Westonia surface represented on O. (W.) ella, although it is exceedingly fine.

The generic name was given in honor of Mr. T. C. Weston.

OxsoLtus (WESTONIA) ALANDENSIS Walcott.

Plate XLVIII, figures 6, 6a.

Lingula? sp. No. 2, Wiman, 1902, Bull. Geol. Inst. Univ. Upsala, vol. 6, pt. 1, No. 11, p.52, Pl. II, fig. 39. (Locality
given.
Egagpine 2 be No. 3, Wman, 1902, idem, p. 52, Pl. II, fig. 33. (Locality given. The specimen represented by fig. 33

is redrawn in this monograph, Pl. XLVIII, fig. 6.)

Lingulella? sp. No. 5, Wm an, 1902, idem, p. 52, Pl. II, fig. 35. (Locality given. The specimen represented by fig. 35
is redrawn in this monograph, Pl. XLVIII, fig. 6a.)

Obolus (Westonia) alandensis Watcort, 1905, Proc. U. 8. Nat. Mus., vol. 28, p. 334. (Discussed essentially as below
as a new species.)

This species is characterized by its broad form when compared with Obolus ( Westonia)
botinicus (Wiman), O. (W.) wimani Walcott, and O. (W.) balticus Walcott. Its surface is marked
by fine concentric lines of growth, with very fine, threadlike, concentric striz between them.
In strong, reflected light, almost microscopic, transverse, very irregular lines can be seen that
give the surface somewhat the appearance of that of O. (W.) ella (Hall and Whitfield).

For reference to the geological horizon of bowlders on Eggegrund Island, similar to the
ones containing this species, see description of O. (W.) bottnacus Walcott, p. 454.

The species derives its specific name from its occurrence on Aland Island.

ForMATION AND LOCALITY.—Middle? Cambrian: (311j and 311k) Drift bowlders of bituminous sandstone, Nos.
28 and 29 [Wiman, 1902, p. 57], on Biludden, about 20 miles (32.2 km.) east of Gefle, Province of Gefleborg;
and (311m) drift bowlder of bituminous sandstone, No. 1 [Wiman, 1902, p. 57], on Lim6n Island, about 12 miles (19.3

km.) northeast of Gefle, Province of Gefleborg; all in Sweden.
(811ly) Drift bowlder of rusty sandstone [Wiman, 1902, p. 57], at ¥ tternés, Slemmern, Aland Island, Finland, Russia.

OxBoLuS (WESTONIA) AURORA (Hall).

Plate XLVI, figures 1, la-h.

Lingula aurora Haun, 1861, Rept. Supt. Geol. Survey Wisconsin, p. 24.

Linguia aurora Haun, 1862, Rept. Geol. Survey Wisconsin, vol. 1, p. 21, fig. 4. (No text reference.)

Lingula aurora Hawn, 1863, Sixteenth Ann. Rept. New York State Cab. Nat. Hist., pp. 126-127, Pl. VI, figs. 4 and 5.
(Described and discussed.)

Lingula aurora Hat, 1867, Trans. Albany Inst., vol. 5, pp. 103-104, Pl. I, figs.4and 5. (Copy of preceding reference.)

Lingulella aurora Haux, 1873, Twenty-third Ann. Rept. New York State Cab. Nat. Hist., pp. 244-245. (Merely
changes generic reference.)

AUD - CAMBRIAN BRACHIOPODA.

Lingulella aurora (Hall), Hatt and CrarKe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, Pl. II, figs. 12 and
13. (No text reference.)

Lingula aurora Hall, SARpEson, 1896, Bull. Minnesota Acad. Nat. Sci., vol. 4, No. 1, pt. 1, p. 95. (New localities
mentioned.)

Obolus (Westonia) aurora (Hall), Wancorr, 1901, Proc. U. S. Nat. Mus., vol. 23, p. 691. (Merely changes generic
reference.)

Lingulella aurora (Hall), GRaBAU and SxtmeEr, 1907, North American Index Fossils, vol. 1, p. 193. (Described.)

General form broadly ovate, with the dorsal valve almost subcircular, except for the gentle
slope of the cardinal margins toward the low obtuse beak. The beak of the ventral valve is
almost invariably broken off, as shown in Plate XLVI, figures 1a to 1d. If the cardinal slopes
are restored, as in figure 1c, the form of the beak is rather obtuse. Original convexity unknown,
as all of the large number of specimens in the collection are compressed and often flattened on
the surface of the shaly sandstone. It appears to have been moderate like that of Lingulella
ampla (Owen) and Obolus ( Westonia) stoneanus (Whitfield). The shell appears to have been
built up of a thin outer layer and thin lamellose inner layers. On some of the casts of the valves
the character of both the mner and outer surface markings is shown.

The outer surface of the shell is marked by concentric striz and lines of growth and a

complex system of lamellose striz. The latter are almost directly transverse near the sides of
the shell and curve slightly backward over the central portion, where they have a sharp zigzag
character that is highly characteristic (Pl. XLVI, figs. 1g and 1h). When the outer surface of
the shell is exfoliated the surface is marked by concentric lines and striz and fine radiating striz
(figs. 1 and 1b). This latter surface is probably caused by the markings of the inner surface of
the shell and the inner surface of the outer layer or lamella, as is seen so frequently in the shell
‘of Lingulella acutangula (Roemer) (Pl. XVII) and Dicellomus politus (Hall) (Pl. LID. The
appearance of several specimens leads to the conclusion that the interior surface was more or
less punctate. It frequently happens that the outer surface of the shell is worn nearly smooth,
the only remaining traces of the beautiful surface ornamentation being toward the beak, or a
spot here and there protected by a strong raised line of growth.

This is one of the largest shells of the genus. A ventral valve from Mazomanie is 21 mm.
long, with a maximum width of 17 mm., and an associated dorsal valve is 17.5 mm. long and 17
mm. in width. The cardinal area is well defined in both valves. In the ventral valve it is
divided at the center by a strong pedicle groove and toward its margins by narrow, clearly
defined flexure lines. The striz of growth cross the area parallel with its base (Pl. XLVI, fig. 1¢).

The area formed a thin shelf between the pedicle groove and the lateral margins, and the
undercut extended back beneath the area, but how far can not be determined, as the cast of it
is broken away in the specimens in the collection.

The area of the dorsal valve is short as compared with that of the ventral valve. It extends
well out on the cardinal slopes, and has a very faintly indicated flexure line near the lateral
margin. The cast of the visceral cavity (v) is partly shown in figure la. There is a peculiar
apron-like area that extends forward from the flattened cast of the pedicle groove (Pl. XLVI,
figs. 1b-d) that probably represents a broad groove that existed in the interior of the shell
back of the visceral cavity. No clearly defined muscle scars have been observed.

Observations.—The surface ornamentation is very characteristic, and is of the same general
type as that of Obolus (Westonia) ella. (Compare Pl. XLVI, fig. 1h, with Pl. XLVI], fig. 10.)

The outline of the valves is somewhat like that of Lingulella ampla (Owen) (Pl. XXVIII).
It differs in being wider in proportion to the length. As pointed out by Hall, Obolus (Westonia)
aurora is from the upper beds at Mazomanie and Lingulella ampla from the lower beds at
Trempealeau.

ForMATION AND LOCALITY.—Upper Cambrian: (S85x)¢ In the upper beds of the “St. Croix sandstone,” near Mazo-

manie, Dane County; (85s) ‘‘St. Croix sandstone,’’ at Prairie du Sac, Sauk County; (78, 78c, and 78s) “‘St. Croix sand-
stone” at Osceola, Polk County; (79) ‘‘St. Croix sandstone,”’ in bluff near Hudson, St. Croix County; (86) “‘St.

a $85x is the type locality, though the specimens in the United States National Museum collections to which that number is assigned were
collected much later than the type specimens. The species also occurs in Localities 3281 and 3828p. -

OBOLIDA. 453

Croix sandstone,”’ at Van Ness quarry, Gibraltar Bluff, Lodi, Columbia County; and (328b) St. Lawrence formation
[Sardeson, 1896, p. 95], at Osceola, Polk County; all in Wisconsin.

(339a) St. Lawrence formation [Sardeson, 1896, p. 95], at Otisville, Washington County; and (97 and 339c) Reeds
Landing, foot of Lake Pepin, Wabasha County; both in Minnesota.

OxBoLus (WESTONIA) BALTICUS Walcott.
Y Plate XLVIII, figures 7, 7a-b.

Lingulella? sp. No. 4, Wrman, 1902, Bull. Geol. Inst. Univ. Upsala, vol. 6, pt. 1, No. 11, p. 52, Pl. II, figs. 37 and
38. (Locality given. The specimens represented by figs. 37 and 38 are redrawn in this monograph, Pl. XLVIII,
figs. 7a and 7b, respectively.)

Lingulella? sp. No. 6, Wmtan, 1902, idem, p. 52, Pl. II, fig. 34. (Locality given. The specimen represented by fig.
34 is redrawn in this monograph, Pl. XLVIII, fig. 7.)

Obolus (Westonia) baltica Waucort, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 334. (Characterized as below as a new
species. )

This species is characterized by its elongate form, with the sides of the dorsal valves regu-
larly rounded from the back to the rounded frontal margin. The dorsal valves are also more
regularly and strongly convex than in other species occurring in the Cambrian sandstones of
Sweden. The outer surface is marked by concentric and radiating striz, crossed obliquely by
very fine, irregular transverse striz. The latter are only to be seen with a strong magnifier
and favorable light.

For reference to the geologic horizon of bowlders on Eggegrund Island, similar to the ones
containing this species, see description of Obolus ( Westonia) bottnicus, page 454.

The species derives its name from its occurrence in the North Baltic region.

FORMATION AND LocaLity.—Middle? Cambrian: (311h) Drift bowlder of bitwminous sandstone, No. 26 |Wiman,
1902, p. 57), on Biludden, about 20 miles (32.2 km.) east of Gefle; and (3110) drift bowlder of bituminous sandstone, No. 1
[Wiman, 1902, p. 57], on Skalstenarne Island, just west of Eggegrund Island, about 25 miles (40 km.) east-northeast
of Gefle; both in the Province of Gefleborg, Sweden.

(811t) Drift bowlder of mottled calcareous sandstone [Wiman, 1902, p. 57], at Ofverby, parish of Jomala, Aland
Island, Finland, Russia.

Obolus (Westonia) blackwelderi Watcort, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 335. (Described and discussed as
below as a new species.)

OBOLUS (WESTONIA) BLACKWELDERI Walcott.

Plate XX XIX, figures 10, 10a-c.

General form elongate, with the width about one-half the length; front margin broadly
rounded; sides slightly arched up to the lateral slopes, which are quite straight in the ventral
valve and curved toward the rounded posterior end of the dorsal valve; the beak of the ventral
valve is pointed and marginal. The convexity of the valves is moderate, that of the dorsal
apparently being the greater. Surface marked by concentric strize and lines of growth which
are crossed by irregular, fine, imbricating, more or less transverse lines; the transverse lines
trend slightly backward toward the sides of the valves. A dorsal valve 8 mm. in length has a
width of 5 mm.

Observations.—Nothing is known of the interior of the valves. When the shell is broken
from the limestone, the outer surface usually adheres to the matrix. The best exteriors are
those of shells on the surface of the layers. Of the known species of Westonia, 0. ( W.) wimani
Walcott, and O. (W.) balticus Walcott are most nearly related to O. (W.) blackwelderi. The
latter is a larger shell and also less narrow proportionally where the gently arching sides pass
into the posterolateral slopes.

The specific name is given for Prof. Eliot Blackwelder, of the University of Wisconsin, who
collected the specimens.

FORMATION AND LOCALITY.—Middle Cambrian: (C1 and €2) Lower shale member of the Kiulung group [Black-
welder, 1907a, pp. 37 and 40 (part of the 3d list of fossils), and fig. 10 (bed 4), p. 38], 2 miles (3.2 km.) south of
Yenchuang; and (€6) thin slabby limestone wn the wpper shale member of the Kiulung growp [Blackwelder, 190%a, pp. 37

and 41 (2d list of fossils), and fig. 10 (bed 12), p. 88], 2.5 miles (4 km.) southwest of Yenchuang; both in the Sintai
district, Shantung, China.

454 CAMBRIAN BRACHIOPODA.

Oxsotus (WEsroniaA) BOTTNICUS (Wiman),
Plate XLVIII, figures 4, 4a-c.

Lingula bottnica Wrman, 1902, Bull. Geol. Inst. Univ. Upsala, vol. 6, pt. 1, No. 11, p. 51, Pl. II, figs. 40-44. (Charac-
terized and discussed in German as a new species. The specimens represented by figs. 41, 42, 48, and 44 are
redrawn in this monograph, Pl. XLVIII, figs. 4, 4a, 4b, and 4c, respectively.)

Obolus ( Westonia) bottnica (Wiman), Watcorr, 1905, Proc. U.S. Nat. Mus., vol. 28, pp. 335-336. (Characterized and
discussed as below.)

The description of Obolus (Westonia) finlandensis Walcott so closely applies to this species
that it is only necessary to point out the difference between the two and to compare the figures
illustrating them.

The surface of Obolus (Westonia) botinicus has the same concentric and radiating lines with
the irregular, transverse lines terminating at right angles to the margins, curving inward and
backward in such a manner as obliquely to cross the radiating lines that extend from the umbo
forward to the anterior and anterolateral margins. The central scars of the dorsal valve are
much farther forward in O. ( W.) bottnicus.

Wiman [1902, p. 51] refers this species to the Olenellus sandstone series. The bowlder
containing it also carried Aparchites? anderssoni, Hupponicharion matthewi, Acrotreta egge-
grundensis, Kutorgina?, Torellella levigata, and fragments referred to Olenellus. This fauna
is essentially Middle Cambrian in its facies and unless the fragments referred to Olenellus are
indisputably of that genus, I am inclined to refer the bowlder and its contained fossils to the
Middle Cambrian. The fact that Obolus ( Westonia) bottnicus is nearly identical with O. (W.)
finlandensis of the Middle Cambrian of Finland also points to the Middle Cambrian age of the
fauna.

The specific name is derived from the Swedish form of the word Bothnia.

ForMATION AND LOCALITY.—Middle? Cambrian: (311) Drift bowlder of coarse-grained, somewhat friable, glauconitic
sandstone, No. 3[Wiman, 1902, p. 57], on Eggegrund Island, about 25 miles (40 km.) east-northeast of Gefle, Province of
Gefleborg, Sweden. : :

Specimens which were doubtfully referred to this species by Wiman occur at the following
locality:

Middle? Cambrian: (311le) Drift bowlder of rusty sandstone [Wiman, 1902, p. 57], south of Lumparn, parish
of Jomala, Aland Island, Finland, Russia.

OBoLUS (WESTONIA) CHUARENSIS (Walcott).

\
‘ Plate XXV, figures 2, 2a-e.

Obolus (Lingulella) chuarensis Waxtcort, 1898, Proc. U. S. Nat. Mus., vol. 21, p. 399. (Described and discussed
essentially as below as a new species.)
Obolus (Westonia) chuarensis Watcort, 1901, Proc. U.S. Nat. Mus., vol. 23, p.691. (Merely changes generic reference.)

General form broadly ovate, almost subquadrate, with the ventral valve obtusely acuminate,
and the dorsal valve rounded subquadrate, the posterior margin being broadly obtuse; convexity
moderate, increasing somewhat in the older shells. Surface of shell marked by rather strong,
concentric lines and striz of growth and very fine, more or less transverse and irregular, appar-
ently imbricating striz such as ornament the surface of Obolus (Westoma) ella (Hall and Whit-
field) and O. (W.) euglyphus (Walcott). Kime radiating striz also appear under a strong
magnifying glass. When the outer surface is exfoliated the inner layers of the shell show
traces of radiating striz. The mner surface is marked by pits or puncte, arranged i more or
less irregular concentric lines;. also fine radiating striz. The shell is strong and formed of a
thin outer layer and several inner layers or lamelle, those near the outer margin being arranged
obliquely to the outer surface.

The only traces of the interior markings are those on the casts of the dorsal valve. These
show a short and rather broad area, strong vascular sinuses, and traces of the anterior lateral
muscle sears.

OBOLIDA. 455

Observations.—The character of the surface ornamentation and subquadrate form of the
‘dorsal valve lead to a comparison with O. (W.) ella (Hall and Whitfield) (Pl. XLVII) of the
Rocky Mountain fauna. The species differs from the latter in having a thicker, stronger shell,
‘relatively shorter in proportion to its length. The surface is also of the same type as that
of O. (W.) euglyphus (Walcott) (Pl. XLVIII), which occurs at the same horizon in the upper
portion of the ‘‘Tonto” sandstone but not associated with it. It differs from O. (W.) euglyphus
‘in being much shorter and broader in proportion to its length.

The species derives its name from its occurrence in the Chuar Valley, Grand Canyon of the
Colorado, Arizona.

FoRMATION AND LOCALITY.—Middle Cambrian: (74) Sandstone about 300 feet (91.4 m.) above the base of the
Tonto group at the head of Nunkoweap Valley; (74b) sandstone about 1,000 feet (305 m.) above the base of the Tonto

group, at the head of Nunkoweap Valley; (73) sandstones of the Tonto group in Kwagunt Valley; and (73a) “‘ Tonto”
sandstone, in Chuar Valley; all in the Grand Canyon of the Colorado, Arizona.

OBoLus (WESTONIA) DARTONI (Walcott).
a Text figures 40A-C.

Obolus ( Westonia) dartoni Waxcort, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, p- 67, Pl. VII, fig. 14. (Discussed as

below as a new species. Fig. 14 is reproduced below, fig. 40A. )

This species has the general form and convexity of Obolus’ ( Westonia) euglyphus (Walcott)
(Pl. XLVIII, figs. 1, la-e). It differs in the dorsal valve being narrower posteriorly. The
surface of the two species differs very much,
that of O. (W.) dartons being of the O. (W.)
ella (Hall and Whitfield) type (Pl. XLVI,
fic. 1o) and not like that of O. (W.) euglyphus
(Pl. XLVIII, fig. 1f). From O. (W.) ella
this species differs in being more elongate
in outline and in having the surface more
clearly marked by the crossing of the minute
ridges. These ridges are slightly irregular
and curve from near the umbo obliquely

A
FIGURE 40.—Obolus (Westonia) dartont Walcott. A, Ventral valve, worn
across the shell toward the lateral and front smooth py beach action (U. S. Nat. Mus. Cat. No. 51683a). B, Dorsal

: : valve, worn smooth (U.S. Nat. Mus. Cat. No. 51683b). C, Enlargement of
margms SO as to form a pattern much like the surface, X 10 (U. S. Nat. Mus. Cat. No. 51683c).

that shown on the front portion of Plate The specimens represented are from Locality 3020, Middle Cambrian
XLVI, ficure le. Some portions of the sandstones near Garfield Peak, Wyoming. Figure 40A is copied from
? =) 0 Walcott [1908d, Pl. VII, fig. 14]; it represents the type specimen.

surface recall that of the central portions
of Plate XLVI, figure 1h. The largest ventral valve has an indicated length of 12 to 15
mm.; width, 9 mm.

The specific name was given for Mr. N. H. Darton, of the United States Geological Survey,
who collected the specimens.

ForMATION AND LOCALITY.—Middle Cambrian: (3020) Sandstones just above the granite, west of Garfield Peak,
50 miles (80.5 km.) west of Casper, Natrona County, Wyoming.

Oxotus (WeESTONIA) ELLA (Hall and Whitfield.)
Plate XX XIII, figures 3, 3a-c; Plate XLVII, figures 1, la—p.

Lingulepis ella Haut and Wurrrievp, 1877, U.S. Geol. Expl. 40th Par., vol. 4, p. 232, Pl. I, fig. 8. (Described and
discussed as anew species. The specimen represented by fig. 8 is redrawn in this monograph, Pl. XLVII, fie. 1b.)

Lingulella ella (Hall and Whitfield), Watcorr (in part), 1886, Bull. U.S. Geol. Survey No. 30, pp. 97-98, Pl. VII,
fig. 2; Pl. VILI, figs. 4, 4a, 4d, and 4e (not figs. 4b and 4c, now referred to Lingulella dubia). (Copies original
description and describes and discusses species. Fig. 4 is redrawn from the specimen represented in fig. 8 of
the preceding reference. The specimens represented by figs. 2 and 4 are redrawn in this monograph, Pl.
XLVII, figs. Im and 1b, respectively.) si

Lingulella ella (Hall and Whitfield), Watcort (in part), 1891, Tenth Ann. Rept. U. S. Geol. Survey, p. 607, Pl. LXVII,
figs. 2, 2a-b, and 2e (not figs. 2c and 2d, now referred to Lingulella dubia). (Horizons mentioned. Figs. 2, 2a—b,
and 2e are copied from figs. 2, 4a, 4, and 4e, respectively, of the preceding reference.)

456 CAMBRIAN BRACHIOPODA.

Lingulella ella (Hall and Whitfield), Haut and Ciarxe (in part), 1892, Nat. Hist. New York, Paleontology, vol. 8,
pt. 1, p. 58, figs. 19 and 21 (not fig. 20, now referred to Lingulella dubia). (Species discussed inthe text. Figs,
19 and 21 are copied from Walcott, 1886b, Pl. VII, fig. 2, and Pl. VIII, fig. 4a.)

Lingulepis ella Hall and Whitfield, Waxcorr, 1897, Am. Jour. Sci., 4th ser., vol. 8, p. 404. (Merely changes generic
reference.

Obolus esi ella (Hall and Whitfield), Waxcorr, 1898, Proc. U. 8S. Nat. Mus., vol. 21, Pl. XXVIII, figs. 5-8.
(No text reference. The specimens represented by figs. 5-8 are redrawn in this monograph, Pl. XLVII,
figs. 1g, 1k, 1d, and 1i, respectively.)

Obolus (Westonia) ella (Hall and Whitfield), Waxcorr, 1901, Proc. U. 8. Nat. Mus., vol. 23, p. 691. (Merely changes
generic reference.) i

Obolus ella (Hall and Whitfield), Marranw, 1902, Trans. Roy. Soc. Canada for 1902, 2d ser., vol. 8, sec. 4, No. 3, pp. 96
and 110, Pl. I, figs. 9a-b. (Discussed on both pages.)

Lingulella ella (Hall and Whitfield), Pack, 1906, Jour. Geol., vol. 14, No. 4, p.295, Pl. I, figs. 2 and-2a. (Mentioned,
and new localities given.)

Lingulella (Westonia) ella (Hall and Whitfield), GRaAbAv and Sammr, 1907, North American Index Fossils, vol. 1,
p. 193, figs. 229a-b. (Described. Figs. 229a-b are copied from Walcott [1886b, Pl. VIII, figs. 4 and 4a,
respectively ].)

General form broad ovate, with the dorsal valve subquadrate or rounded quadrate and
the ventral valve obtusely acuminate; valves moderately convex, so far as can be determined
from the crushed and flattened specimens from the shales of Utah and Nevada. Surface of
the shell marked by concentric striz and lines of growth and, on the type specimen, by very
fine, irregular, lamellose, more or less transverse strie and fine radiating lines; the surface is ~
much like that of O. (W.) euglyphus (Walcott) (Pl. XLVIII); fine, clearly defined radiating
lines occur on the inner layer of the shell of partly exfoliated specimens. The cast of the mner
surface of the shell shows papill that filled puncte in the shell; they are rather large and are
arranged in the central portion of the shell in concentric lines, much as in Lingulella davist.
The shell is strong and rather thick in old shells. It is made up of a thin outer layer and several
inner layers or lamellx that are well shown in the figure of the type specimen (Pl. XLVII,
fig. 1b). :

The .argest ventral valve thus far examined has a length of 16 mm. and a width of 13 mm.
A dorsal valve is 13 mm. long by 12.5 mm. in width.

The area of the ventral valve is of the same type as that of O. (W.) aurora (Hall) (PI.
XLVI) and Lingulella ampla (Owen) (Pl. XXVIII). The flexure line is nearer the pedicle fur-
row than in Lingulella perattenuata (Whitfield) (Pl. X XT), L. acutangula (Roemer) (PI. XVII),
Lingulella ampla, and Obolus ( Westonia) aurora, which results in a wider outer lateral space on
the area (Pl..XLVII, fig. 1c (a’)). The pedicle furrow is strong and deeply rounded, and in
one specimen referred to this species (Pl. XLVII, figs. 1d and 1g) the cast of the base of the
undercut between the area and the outer shell is clearly shown on each side of the pedicle groove.
The area of the dorsal valve is low and broad; the flexure lines cross it so as to form a broad,
slightly elevated space in the cast corresponding to a broad, shallow furrow in, the shell (PL.
XLVII, fig. 11). The striz of growth cross the area parallel with its base, both in the ventral
and dorsal valves.

The cast of the interior of the ventral valve shows the visceral cavity (Pl. XLVII, figs. 1c,
1d, and 1g) and the median septum of the dorsal valve is seen in figures 1i and 1k.

The muscle scars are not distinctly shown on the ventral valve. In the dorsal valve the
central scars (h) are preserved in specimens from Nevada (fig. 11) and Montana (figs. 1 and 1k),
and the anterior laterals in Plate XLVI, figures 1k and 11.

The remains of markings made by the vascular system are limited to the main or trunk
sinuses of the two valves, and a portion of the parietal sear (ps) is seen on one specimen of the
ventral valve (Pl. XLVII, fig. 1g).

Observations —The type specimen of this species is a somewhat erushed dorsal valve that
fortunately preserves the outer surface and much of the shell. Near the type locality, and
in the same band of slaty shales, were found a number of specimens, including a series of young
shells. Two of the larger shells are shown by Plate XLVI, figures 1 and 1a, and two of the

OBOLIDA. 457

young by figures le and 1f. The shells found near Helena, Montana, commonly occur as casts
in a siliceous shale and have the form of and appear to be specifically identical with the species
in the Wasatch and Oquirrh mountains. A few specimens preserve the shell and show it to
be thick and strongly laminated toward the front.

The form from the Bighorn Mountains of Wyoming appears to be identical with this
species, except that the surface ornamentation is coarser and much more distinctly outlined by
the zigzag, irregular, transverse strie. The strength of the strive and the size of the more or
less rhombic interspaces range from near those of O. (W.) ella to more than double their size,
the increase in the size of the interspaces being made more prominent by the deposition of
what appears to be chalcedony on the outer surface or a replacement of the shell by chalcedony.
The form of the valves and the position of the central and anterior lateral muscle scars in the
dorsal valve are essentially the same as in O. (W.) ella.

On Gordon Creek in Montana this species occurs in association with the Albertella helena
fauna [Walcott, 1908f, p. 202], which is referred to the highest zone of the Lower Cambrian.
Four small ventral valves were found that have the form and surface characteristic of Obolus
(Westona) ella. ;

Obolus ( Westonia) ella has a wide geographic distribution in the Cordilleran and southern
Appalachian regions. It also has a vertical range from the summit of the Lower Cambrian
in Montana and British Columbia to 250 feet up in the Upper Cambrian.

FORMATION AND LOCALITY.—Upper Cambrian: (4y and 54t) Limestone of the St. Charles formation [Walcott, 1908a,
p- 6], about 250 feet (76 m.) above the Middle Cambrian on the north side of Twomile Canyon, near its mouth, 2 miles
(3.2 km.) southeast of Malade, Oneida County, Idaho.

(54e) About 200 feet (61 m.) above the Middle Cambrian and 1,025 feet (212.4 m.) below the top of the Upper
Cambrian in limestones forming 3 of the St. Charles formation [Walcott, 1908f, p. 193], in Blacksmith Fork Canyon,
about 10 miles (16.1 km.) east of Hyrum, Cache County, Utah.

Middle Cambrian: (57g) About 1,700 feet (518 m.) above the Lower Cambrian and 3,250 feet (991 m.) below the
Upper Cambrian, in the siliceous shales forming 2d of the Stephen formation [Walcott, 1908f, p. 211], on Mount Bos-
worth, north of the Canadian Pacific Railway between Hector and Stephen, on the Continental Divide, between
British Columbia and Alberta, Canada.

(5f) Limestone interbedded in the Wolsey shale [Weed, 1900, p. 285], in Meagher County, on the road to Wolsey,
about 4 miles (6.4 km.) south of the divide at the head of Sawmill Creek, and 11 miles (17.7 km.) south of Neihart,
Little Belt Mountains quadrangle (U. S. Geol. Survey), Cascade County; (340a) shales near Helena, Lewis and Clark
County; (302s) dark siliceous shale in a quarry in Last Chance Gulch, south slope of Mount Helena, 1.5 miles (2.4 km.)
south of Helena, Lewis and Clark County; (4u) shales in the Gallatin formation of Peale [1893, Pl. IV], northwest side of
canyon 0.5 mile (0.8 km.) south of Helena, Lewis and Clark County; (9m) shale 4 miles (6.4 km.) above Walker’s ranch,
on North Fork of Dearborn River, in the eastern part of the Lewis and Clark National Forest, Lewis and Clark County;
(4q’) limestone about 310 feet (94.5 m.) above the unconformable base of the Cambrian and 185 feet (56.4 m.) above
the top of the quartzitic sandstones in a shale which corresponds in stratigraphic position to the upper part of shale
No. 6 of the Dearborn River section [Walcott, 1908f, p. 202], on the ridge between Gordon and Youngs creeks, about
halfway between Gordon Mountain and Cardinal Peak, Ovando quadrangle (U. 8. Geol. Survey), Powell County;
(4k) about 725 feet (221 m.) above the base of the Cambrian in the shales of the Gallatin formation of Peale [1893, Pl.
TV], on the north side of West Gallatin (Gallatin) River, northeast of Logan, Threeforks quadrangle (U.S. Geol. Survey),
Gallatin County; and (4g) about 325 feet (99.1 m.) above the base of the Cambrian in the Flathead shales of Peale
[1893, p. 21], 1 mile (1.6 km.) north of the junction of East Gallatin and West Gallatin (Gallatin) rivers, 4 miles (6.4
km.) east-northeast of Logan, Threeforks quadrangle (U. 8. Geol. Survey), Gallatin County; all in Montana.

(5h and 55d) About 2,000 feet (609.6 m.) above the Cambrian quartzitic beds in a shale which is probably to be
referred to the Bloomington formation [Walcott, 1908a, p. 7], on the south side of Twomile Canyon, near its mouth,
2 miles (3.2 km.) southeast of Malade, Oneida County; and (55¢e) Spence shale member of the Ute limestone [Walcott,
1908a, p. 8], about 50 feet (15.2 m.) above the Brigham quartzite and 2,755 feet (839.7 m.) below the Upper Cambrian,
in a ravine running up into Danish Flat from Mill Canyon, about 6 miles (9.6 km.) west-southwest of Liberty and 15
miles (24.2 km.) west of Montpelier, Bear Lake County; both in Idaho.

(171a) Sandstone in Big Goose Creek Canyon, in the Bighorn Mountains, west of Sheridan, Sheridan County;
and (4n) limestone about 325 feet (99.1 m.) above the unconformable base of the Cambrian in divide at the head of
Jackson Creek (locally known as Sheep Creek), a creek flowing into Jackson Lake about 0.5 mile (0.8 km.) south of its
northwestern corner, Teton Mountains, Grand Teton quadrangle (U.S. Geol. Survey), Uinta County; both in Wyoming.

(3g) Shales on the river bank 250 feet (76.2 m.) above the west:end of the Denver and Rio Grande Railroad
tunnel, Glenwood Springs, Garfield County, Colorado.

458 CAMBRIAN BRACHIOPODA.

(829c) In Weber Canyon, about 2.5 miles (4 km.) northeast of Peterson, Morgan County; (30p) about 125 feet
(88 m.) above the Cambrian quartzitic sandstones, on the north side of Ogden Ceara, about 1 mile (1.6 km.) above
its mouth, east of Ogden, Weber County; and (30a) shale on north side of Big Cottonwood Canyon, 1 mile (1.6 km.)
below Argenta, Wasatch Range, southeast of Salt Lake City, Salt Lake County; all in Utah.

(82y) Shales about 175 feet (53.3 m.) above the Brigham quartzite [Walcott, 1908a, p. 8], in the Wasatch Moun-
tains, 1 mile (1.6 km.) northwest of Geneva (Copenhagen), east of Brigham; (32p and 55e) Spence shale member of the
Ute limestone, about 100 feet (30.5 m.) above the Brigham quartzite [Walcott, 1908f, p. 197], in Wasatch Canyon, east
of Lakeview Ranch, 5 miles (8 km.) north of Brigham; and (829) green shales in a canyon about 7 miles (11.2 km.)
north of Brigham (near the village of “Calls Fort” | Hague, 1877, p. 405]); all in Boxelder County, Utah.

(31e and 54a) About 750 feet (228.6 m.) above the Brigham quartzite and 3,440 feet (1,048.5 m.) below the Upper
Cambrian, in the shales forming 2a of the Ute limestone [Walcott, 1908i, p. 196], in Blacksmith Fork Canyon, about
10 miles (16.1 km.) east of Hyrum, (32d) shales about 150 feet (45.7 m.) above the Brigham quartzite [Walcott, 1908a,
p- 8], on the east side of the south fork of Paradise Dry Canyon (locally known as Hast Fork), east of Paradise; and
(31z and 55t) about 350 feet (106.7 m.) above the Brigham quartzite, in the Ute limestone [Walcott, 1908a, p. 7], on
west side of road 0.5 mile (0.8 km.) above the forks, Paradise Dry Canyon, east of Paradise; all east of Cache Valley,
Cache County, Utah.

(320) Shale about 325 feet (99 m.) above the Cambrian quartzitic sandstones, 2 miles (3.2 km.) southeast of Muskrat
Spring, on the northwest face of Grantsville Peak, Stansbury Range; (8d) concretionary limestone about 100 feet (30.5 m.)
above the Cambrian quartzitic sandstones, at Ophir, Oquirrh Range; (329e) shales in East Canyon, above Ophir,
Oquirrh Range; (8c) shales about 75 feet (22.9 m.) above the Cambrian quartzitic sandstones, at Ophir, Oquirrh
Range; and (32h and 32z) shales in a canyon on the west side of the Simpson Range, 4 miles (6.4 km.) south of Simpson
Spring, about 20 miles (32.2 km.) west-southwest of Vernon; all in Tooele County, Utah.

(30d) About 1,020 feet (310.9 m.) above the Lower Cambrian and 3,400 feet (1,036.3 m.) below the Upper Cambrian
in the limestone forming le of the Swasey formation [Walcott, 1908f, p. 182], at the head of Dome Canyon; and (31s)
490 feet (149.4 m.) above the Lower Cambrian and 3,925 feet (1,196.3 m.) below the Upper Cambrian in the pinkish
argillaceous shale forming 1d of the Howell formation [Walcott, 1908f, p. 182], south side of Dome Canyon about 1
mile (1.6 km.) below the divide; both about 3 miles (4.8 km.) west-southwest of Antelope Springs, House Range
[Walcott, 1908f, Pl. XIII], Millard County, Utah.

(31) Shales on the dump of the Chisholm mine; (333b [Pack, 1906, p. 295]) shales on the dump of the Half-moon
mine; (338a [Pack, 1906, p. 295]) shales on the dump of the Himon mine; (333 [Pack, 1906, p. 295]) shales on the dump
of the Abe Lincoln mine; (7k) shales in the dumps of the Half-moon and Chisholm mines, southwest slope of Ely Moun-
tains; and (31u) shales on the west slope of the spur facing the main part of the Highland Range; all about 3 miles
(4.8 km.) northwest of Pioche, Lincoln County, Nevada.

(90) Conasauga (‘‘Coosa”) shale, on Edwards farm, near Craigs Mountain, about 10 miles (16.1 km.) southeast of
Center, Cherokee County; and (141a) limestone 0.25 mile (0.4 km.) west of the hotel at Montevallo, Shelby County; both
in Alabama.

(14a) Sandstone of the Rome formation along First Creek Gap, 4 miles (6.4 km.) north-northeast of Knoxville
[Keith, 1905, areal geology sheet], Knox County, Tennessee.

Lower Cambrian: (4v) About 200 feet (61 m.) above the unconformable base of the Cambrian and 75 feet (22.9 m.)
above the top of the quartzitic sandstones in a shale which corresponds in stratigraphic position to shale No. 6 of the
Dearborn River section [Walcott, 1908f, p. 202], on Gordon Creek, 6 miles (9.6 km.) from South Fork of Flathead River,
Ovando quadrangle (U. 8. Geol. Survey), Powell County, Montana.

(831) About 100 feet (30.5 m.) above the Prospect Mountain quartzite in the shales of the Pioche formation [Wal-
cott, 1908f, p. 171], 0.25 mile (0.4 km.) below the Maxfield mine, Big Cottonwood Canyon, west front of the Wasatch
Mountains, southeast of Salt Lake City, Salt Lake County, Utah.

(30) Hight miles (12.8 km.) north of Bennetts Spring, on the west slope of the Highland Range, Lincoln County,
Nevada.

Specimens that are somewhat doubtfully referred to Obolus (Westonia) ella occur at the
following localities:

Middle Cambrian: (57y) About 1,900 feet (579 m.) above the Lower Cambrian and 3,050 feet (930 m.) below the
Upper Cambrian, in the siliceous shales forming 2a of the Stephen formation [Walcott, 1908f, p. 211], on Mount Bos-
worth, north of the Canadian Pacific Railway between Hector and Stephen, on the Continental Divide between British
Columbia and Alberta, Canada.

(31d and 541) About 500 feet (152.4 m.) above the Brigham quartzite and 3,700 feet (1,127.8 m.) below the Upper
Cambrian, in the Spence shale member of the Ute limestone [Walcott, 1908f, p. 197], in Blacksmith Fork Canyon,
about 10 miles (16.1 km.) east of Hyrum, Cache County; (32n) shales about 725 feet (221 m.) above the Brigham quartzite
[Walcott, 1908a, p. 8], in the Wasatch Mountains, 1 mile (1.6 km.) northwest of Geneva (Copenhagen), east of Brigham,
Boxelder County; and (11s) shales just above Simpson Spring, about 20 miles (82.2 km.) west-southwest of Vernon,
on the stage road from Vernon to Fish Springs, Tooele County; all in Utah.

se

OBOLIDA. 459

V OxBoLuUs (WESTONIA) ELLA ONAQUIENSIS Walcott.
Plate XLIX, figures 6, 6a.

Obolus (Westonia) ella onaquiensis Waxcorr, 1908, Smithsonian Misc. Coll., vol. 53, No. 8, pp. 67-68. (Discussed as
below as a new variety.)

This variety is represented by a number of more or less imperfect specimens that at first
sight might be placed with Obolus ( Westonia) ella (Hall and Whitfield), but the character of the
surface clearly distinguishes the two forms. In typical forms of O. (W.) ella the transverse
striz are more regular, while in this variety they are in the form of sharp, finely zigzag, trans-
verse striz much like the shells of the species from the Bighorn Mountains. This surface is
formed by the interruption of very fine sharp ridges that curve from the umbo outward toward
the sides and front of the shell like engine-turned striz on a watch case.

This form derives its varietal name from its occurrence in the Onaqui Range of Utah.

FORMATION AND LOCALITY.—Middle Cambrian: (33f) Shales about 400 feet (122 m.) above the Cambrian quartzitic
sandstones, on the western slope of the high peak southwest of Lookout Pass, Onaqui Range, west of Vernon, Tooele
‘County, Utah.

Osoxtus (WesTONIA) ELONGATUS Walcott.

Plate LXIII, figures 8, 8a-d.

Obolus ( Westonia) elongatus Waxcotr, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, p. 68, Pl. VII, fig. 12. (Described
and discussed as below as a new species. Fig. 12 is copied in this monograph, Pl. LXIII*fig. 8a.)

General form elongate oval, with the ventral valve acuminate and the dorsal valve elongate
oval. Convexity unknown, as the shells are all flattened by compression.

The outer surface is marked by fine concentric lines of growth crossed by a series of finely
denticulated, imbricating lines that start on each cardinal slope and extend obliquely forward
across the median line, and then curve out toward the sides of the shell; minute rhomboidal
spaces are formed over the posterior and central portions of the shell by the crossing of the
oblique lines; the denticulated margin faces forward and is seen only on the thin epidermal
layer, while the general system of oblique lmes shows on both the outer layer and the next
inner layer of the shell.

The shell is built up of several thin layers or lamelle. The largest specimen of the ventral
valve has a length of 9 mm.; width, 5 mm.; a dorsal valve 6 mm. long has a width of 4 mm.
Nothing is known of the interior of these valves. —

Observations.—This is a more elongate species than Obolus (Westonia) bottnicus Walcott
and O. (W.) jinlandensis Walcott. The oblique surface lines have the same general direction
as those of the latter species, but they are finely denticulated on their front margin, and cross
at the center at a greater angle.

FORMATION AND LOCALITY.—Middle Ordovician: (105x) Gray, siliceous shales, just below a band of quartzitic

sandstones, probably corresponding in position to the upper part of the Simpson formation of the Oklahoma section,
Wasatch Canyon, east of Lakeview Ranch, about 5 miles (8 km.) north of Brigham, Boxelder County, Utah.’

i OxBoLus (WESTONIA) ESCASONI (Matthew).
Plate XLIX, figures 1, la-f.

Lingulella (?) escasoni MartHEw, 1901, Bull. Nat. Hist. Soc. New Brunswick, vol. 4, pt. 4, No. 19, pp. 270-278, Pl. V,
figs. lat. (Described and discussed as a new species. The specimens represented by figs. 1d and 1g are redrawn
in this monograph, Pl. XLIX, figs. 1b and 1a, laa, respectively.)

Obolus (Westonia) escasoni (Matthew), Waxcort, 1901, Proc. U. S. Nat. Mus., vol. 23, p. 691. (Merely changes generic
reference.)

Westonia escason MatrHEw, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, pp. 206-209, Pl. XVI,
figs. lai. (Copied from Matthew, 190la, pp. 270-273, Pl. V, figs. 1a-i.) E

General form ovate, with the ventral valve broadly subacuminate and the dorsal valve
rounded oval in outline. The valves are moderately convex, the ventral being most prominent

460 CAMBRIAN BRACHIOPODA.

toward the beak. The convexity gives a depth of about 1 mm. to shells 5 mm. in diameter.
Surface marked by radiating striz, concentric lines of growth, and fine, more or less undulating
transverse striae. When the thin outer layer of the shell is exfoliated, the next layer is marked
by rather strong, radiating striae and concentric strive and lines of growth. The inner surface
of the shell is strongly pitted, even over the visceral area, and the anterior and lateral margins
are marked by the impressions of the fine canals of the vascular system. ‘The character of the
transverse lines is fully shown by Plate XLIX, figure 1f.

The shell is relatively thick, and formed of a very thin outer layer and several inner layers
or lamellz, which are more or less oblique to the outer layer. These layers are well shown by
the posterior portion of Plate XLIX, figure 1a.

The shell is small, the largest not exceeding 6 mm. in length. The dorsal valve is slightly
shorter than the ventral. The relative dimensions of the two valves may be seen by comparing
figures 1 and 1b of Plate XLIX.

The details of the area of the ventral valve are not well shown by any specimens in the
collection. The pedicle groove appears to have been well marked, and the area to have extended
a short distance out on the cardinal slopes. The area of the dorsal valve is larger in proportion
than usual when compared with that of the ventral valve. The striz of growth cross it parallel
to the anterior margin.

The interior of the ventral valve is shown by Plate XLIX, figure 1a, which beautifully
preserves the central portion, and by the cast (fig. 1). The heart-shaped pit (x), so character-
istic of Obolus, is clearly defined in figure 1a, where it strongly resembles the same space in
Obolus apollinis Kichwald (Pl. VII). No traces of a median septum have been observed in the
ventral valve, but in the dorsal valve the median ridge extends from back of the central muscle
scars to the anterior lateral scars. A strong, pestle-shaped depression extends in the ventral
valve from the area forward to the anterior margins of the visceral cavity. The visceral area.
of the dorsal valve is narrow, elongate, and extends forward to the anterior third of the valve.

Owing to the small size of the shell and the exfoliation along the margins, no one valve
shows all of the muscle scars belonging to it. In Plate XLIX, figure ia, the outside lateral, mid-
dle lateral, and central scars are beautifully defined, but the transmedian and anterior laterals
have not been observed in the ventral valve. Many specimens show the anterior laterals and
centrals of the dorsal valve, also the transmedian. The outside and middle laterals appear to
be combined in one scar a little anterior to the transmedian. The umbonal and pedicle scars
have not been observed.

Of the markings left on the shell by the vascular system the main or trunk canals are the
most prominent. They are, however, rather indistinct in most examples of the dorsal valve
and not specially prominent in the ventral valve. The channels occupied by the fine branches
of the exterior lateral canals are well shown by Plate XLIX, figures 1a and 1c.

Observations.—I have made a very close examination of Matthew’s type material, which
he kindly sent to me for examination, but do not find the muscle scars of the ventral valve
as shown in his figure 1g [Matthew, 1903, Pl. XVI]. On the contrary, as shown in my Plate
XLIX, figure 1a, the outside and middle laterals and central muscle scars are arranged very
much as in Obolus. It is exceedingly difficult to determine the exact position and size of the
muscle scars, but with a strong magnifying glass and reflected light the dull surface of the
point of attachment can often be determined. The peculiar arrangement of the muscle scars
indicated in Matthew’s figure [1903, Pl. XVI, fig. 1g] results from examining the specimen in
a light which raises the ridges bounding the muscle scars so as to give the effect of transverse
lines. I find that the scars are not placed in exactly the same position on the two sides, and
that on the left side it is practically impossible to determine the outside laterals. In the study
of such minute objects there will always be an opportunity for different interpretation, but
with the experience I have had in the study of the Cambrian Brachiopoda, I think the position
given the muscle scars in figure 1a is essentially correct. The characteristic transverse sculp-
ture refers the species to Westonia. It is a beautiful shell and one of the most striking forms
of this type from the Cambrian rocks.

OBOLIDA. 461

The specific name is derived from ‘‘Escasonie,” a local name for that part of Cape Breton
in which the species occurs.

FORMATION AND LOCALITY.—Upper Cambrian: (325 [ Matthew, 1903, p. 208]) Arenaceous shales possibly from the
horizon of the Peléura fauna (Division C3b), on McAdam shore; and (10r)@ arenaceous shales of Division C3a? of Mat-
thew at McAdam shore; both on East Bay, east of Bras d’Or Lake, southeastern Cape Breton, Nova Scotia.

Middle? Cambrian: (100)¢ Arenaceous shales in the railroad cut on the shore of Brasd’Or Lake, at Barachois; and
(11z) sandstone on Big Ridge, 2 miles (3.2 km.) south of Marion Bridge, on the canal of John McDougald; both in
southeastern Cape Breton, Nova Scotia.

OBoLuUS (WESTONIA) EUGLYPHUS (Walcott).
Plate XLVIII, figures 1, la-f.

Obolus (Lingulella) euglyphus Waxcorr, 1898, Proc. U. S. Nat. Mus., vol. 21, pp. 402-403. (Described and dis-

‘cussed essentially as below as a new species.)

Obolus ( Westonia) euglyphus Waxcotr, 1901, Proc. U. S. Nat. Mus., vol. 23, p. 691. (Merely changes generic reference.)

General form ovate, with the ventral valve subacuminate, and the dorsal valve broad
ovate in outline. There is some range of variation in the outline of the valves; this may be
seen by comparing figures 1, 1b, and 1c of Plate XLVIII. The convexity of the valves is
fairly strong and is nearly the same in each, A ventral valve 11 mm. in length has a width of
8 mm., convexity 1.5 mm.; and a dorsal valve 9 mm. in length has a width of 8 mm., con-
vexity 1.5 mm.

The outer surface of the shell is marked by strong concentric lines and strie of growth
and a complex system of lamellose striz of the type of those on Obolus ( Westonia) ella (Hall
and Whitfield). The striz have a transverse direction, are irregular, and sometimes inosculate.
They are somewhat coarser than those on the surface of O. (W.) ella (Pl. XLVII, fig. 11)
and finer than those of O. ( W.) aurora (Hall) (Pl. XLVI, figs. 1h and 1g). They are also less
irrecular than those of O. ( W.) ella, and more so than those of O. ( W.) aurora, the result being
a surface character intermediate between those of the species mentioned. When the outer layer
is exfoliated the surface of the inner layer is marked by numerous fine, radiating strie (Pl.
XLVIII, fig. 1b) and concentric lines of growth. The cast of the inner surface of the shell
shows rather numerous papille that fill the pits or puncte in the shell. The shell is strong
and formed of a thin outer layer and several inner layers or lamellz that are arranged very
much as in Lingulella acutangula (Roemer) (Pl. XVII).

As shown by casts of the interior the cardinal area of the ventral valve is rather long and
well extended out on the cardinal slopes. It is divided at the center by a cast of a strong,
rather deep pedicle furrow, and about three-fifths of the distance between the pedicle furrow
and the lateral margin by a sharp, narrow flexure line. The strize of growth cross the area
parallel to its base. Only a few traces of them are preserved in the pedicle furrow. The area
formed a thin shelf between the pedicle groove and the lateral margins, the undercut extending
far back under the area as in L. acutangula. This is shown in the cast by a thin projection
of the embedding rock over the area (Pl. XLVIII, figs. 1c and 1d). The area of the dorsal
valve is lower and less prominent. It arches forward at the median line and extends well
out on the cardinal slopes.

The cast of the visceral cavity (v) of the ventral valve includes the heart-shaped pit (x)
and a slight trace of the trapezoidal area, in which the central muscle scars and the middle and
outside lateral muscle scars occur. There are no traces of a median septum in the ventral
valve, and it is only slightly indicated in one specimen of the dorsal valve. This is owing,
however, more to the condition of preservation of the specimen than to the character of the
septum. No muscle scars are clearly defined in either valve. Of the vascular system the
main or trunk sinuses are fairly well shown in the ventral valve (Pl. XLVIII, figs. 1¢ and 1d),
but less so for the dorsal valve (Pl. XLVIII, fig. 1e).

Observations —This form has the general shape of Lingulella acutangula (Roemer), but
differs in being more ovate; it also differs in the arrangement of the markings on the interior

@ The specimens from Localities 100 and 10r are somewhat doubtfully referred to this species.

462 CAMBRIAN BRACHIOPODA.

of the valves, particularly the dorsal. In Obolus ( Westonia) euglyphus the traces remaining
on the casts indicate a close resemblance to O. (W.) chuarensis (Walcott), and the surface
ornamentation is of the same character. Attention has been called to the character of the
surface, which is intermediate between that of O. (W.) ella (Hall and Whitfield) (p. 456) and
O. (W.) aurora (Hall) (Pl. XLVI).

This species differs from Lingulella lineolata (Walcott) in its surface characters, thick-
- ness of shell, and usually in outline; it is also usually a larger species, although a few examples
of LZ. lineolata approach it in size. From O. (W.) chuarensis it differs in being much more
elongate and proportionately more ovate in outline.

ForRMATION AND LOCALITY.—Middle Cambrian: (74c) ‘‘Tonto” sandstone, at the head of Lava Canyon; and
(74) sandstones about 300 feet (91.4 m.) above the base of the Tonto growp, at the head of Nunkoweap Valley; both in the
Grand Canyon of the Colorado, Arizona.

OxsoLUS (WESTONIA) FINLANDENSIS Walcott.
Plate XLVIII, figures 3, 3a-b.
Obolus ( Westonia) finlandensis Watcotr, 1902, Proc. U. S. Nat. Mus., vol. 25, pp. 611-612. (Described and discussed
as below as a new species. ) :

General form elongate ovate, with the ventral valve subacuminate and the dorsal valve ovate
in outline. Convexity of the two valves moderate. A ventral valve 11 mm. in length has a
convexity of about 1.25 mm., and a dorsal valve 8 mm. in length has a convexity of 1 mm.
above the plane of the margin.

The outer surface of the shell is marked by concentric lmes of growth with very fine inter-
stitial striez. The latter are crossed by fine, radiating strize that are interrupted more or less
by the concentric lines of growth. In addition to the concentric and radiating striz there is a
series of imbricating lines that are slightly oblique to the longitudinal axis of the shell. These
lines terminate at right angles to the margins, curving inward and backward apparently to the
opposite side. This type of ornamentation is much like that of several species of Westonia,
except that it is somewhat more complicated.

The cast of the interior of the shell shows the interior surface to have been marked by scat-
tered puncte that had a tendency to gather concentrically on the lines of growth. <A few rather
strong radiating striz also occur outside of the visceral area.

The shell is rather thick. It is formed of a thin outer layer and several inner layers or
lamellz that are more or less oblique to the outer surface and marked near the front margin by
fine radiating strie. The largest specimen has a length of 11 mm., with a width of 7mm. A
dorsal valve of the same width has a length of 8 mm.

The area of the ventral valve is unknown. ‘That of the dorsal valve is strongly defined and
extends well forward on the cardinal slopes. It is marked by transverse striz of growth parallel
to the base.

The only interior markings known are in the dorsal valve. These indicate the course of
the main vascular sinus, and the size and length of the median ridge, also the position of the
central muscle scars.

Observations —The oblique, imbricating lines on the outer surface of this species relate it
closely to Obolus ( Westonia) bottnicws (Wiman) and O. (W.) wmani Walcott. The two speci-
mens showing the outer shell are unfortunately shehtly worn along the median line, so that
it is not possible to trace the growth of the oblique, imbricating lines entirely across the shell.
In form the shell resembles Lingulella acutangula (Roemer).

, PorMATION AND Locatiry.—Middle Cambrian: (311x) Compact, fine-grained, quartzitic sandstone at Saltvik,
Aland Island, Finland, Russia.
Oxsotus (WesTontA) reHIs Walcott

Plate XLIX, figures 4, 4a-d.
Obolus (Westonia) iphis Walcctt, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 336. (Described as below as a new species.)

The general form of this shell is well shown by the illustrations. It differs from all other
species of Westonia in having a more elongate and acuminate ventral valve and in the presence

\/

‘OBOLIDAL. 463

of a marked mesial depression on the dorsal valve. The shell is rather thin and made up of
several very thin layers or lamellze. The outer surface is marked by fine radiating strix, con-
centric striz and limes of growth, and fine, more or less undulating, transverse lines that cross
both the radiating and concentric lines. The transverse lines appear to be the edges of slightly
elevated imbricating lamelle of the shell.

FORMATION AND LOCALITY.—Lower Ordovician: (201a) Pogonip limestone, east slope of the ridge east of Ham-
burg Ridge, Eureka district [Hague, 1892, Atlas], Eureka County, Nevada.

Upper Cambrian: (64) Limestone near the Bullwhacker mine, Eureka district [Hague, 1892, Atlas], Eureka
County, Nevada.

(543) About 700 feet (213.4 m.) above the Middle Cambrian and 525 feet (160 m.) below the top of the Upper Cam-
brian, in the arenaceous limestone forming 2c of the St. Charles formation [ Walcott, 1908f, p. 192], in Blacksmith Fork
Canyon, about 10 miles (16.1 km.) east of Hyrum, Cache County, Utah.

OsoLtus? (WESTONIA ?) LAMELLOSUS (Barrande).
“ Plate XII, figures 7, 7a—d.

Eingula lamellosa BARRANDE, 1879, Systéme silurien du centre de la Bohéme, vol. 5, Pl. OVI, figs. r: 1-5; Pl. OXI,
figs. 1x: 1-3. (Not described, but figured as a new species. Pl. CVI, figs. 1: 2A, 1: 3f, and Pl. CX1, figs. rx:
2A; 1x: 1A, and rx: 1f are copied in this monograph, Pl. XII, figs. 7, 7a-d, respectively.)

Obolus (Westonia ?) lamellosus (Barrande), Watcorr, 1901, Proc. U. S. Nat. Mus., vol. 23, p. 691. (Merely changes
generic reference.) 0
This species appears to be the Bohemian Lower Ordovician representative of Obolus ( Wes-

tonia) stoneanus (Whitfield) of the Upper Mississippi Valley Middle Cambrian fauna. The

two forms agree in relative size and proportions and in type of surface ornamentation. This may
be seen by comparing figures 2, 2a-¢, Plate XXVIII, with figures 7, 7a-d, Plate XII. Another
point of similarity is that both species are very abundant in the localities in which they occur.

The principal differences to be noted are that 0.2 (W.?) lamellosus has apparently a thicker
and stronger shell than O. (W.) stoneanuws. This, however, may be due to the fact that all the
specimens of the latter species are more or less flattened im the shaly sandstone, and that the
shell substance has been largely removed by solution. It is on account of the resemblance of
the two forms that Barrande’s species is referred to the genus Obolus and subgenus Westonia,
despite the absence of any knowledge of the area or the interior vascular markings or muscle
sears.

It is hoped that the paleontologists of Bohemia will take up the study of this species and
others that have been referred to Obolus, in order to establish clearly their generic relations.

FORMATION AND LocALIry.—Lower Ordovician: (3031 [Barrande 1879b, Pl. CVI]) Etage dil, Libetschov,
Bohemia, Austria-Hungary.
Oxgpotus (WESTONIA) NoTcHENSIS Walcott.
Vv Plate LXIII, figure 9.
Obolus (Westonia) notchensis Waxcorr, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, p. 69, Pl. VII. fig. 13. (Discussed

as below as a new species. Fig. 13 is copied in this monograph, Plate LXIII, fig. 9.)

This species is represented by two specimens of the ventral valve that have the general
outline of Lingulella ampla (Owen) (Pl. XXVIII, figs. 1a and 1f). The exterior surface is
marked by concentric lines of growth and transverse, irregular, imbricating lines much like
those of Obolus (Westonia) stoneanus (Whitfield) (PI. XXVIII, fig. 2) and O. (W.) iphis (PI.
XLIX, figs. 4a-c). The form of the valve differs from that of the latter species.

The largest specimen has a length of 11 mm., with a maximum width of 9 mm.

The specific name is derived from Notch Peak, Utah, on which the species occurs.

FORMATION AND LOcALiry.—Lower Ordovician: (105t) Thin-bedded, bluish-eray limestone [Walcott, 1908f,
p. 173 and Pls. XIII and XIYVj], at the summit of Notch Peak, House Range, Millard County, Utah.

OxsoLus (WESTONIA) ROGERSE (Walcott).
x Plate XLII, figures 2, 2a-d.

Lingula prima Rocers [not Conrap MS., Hatt], 1861, Proc. Boston Soc. Nat. Hist., vol. 7, p. 390. (Mentioned.)
Lingula antiqua Rocers [not Emmons], 1861, idem, p. 390. (Mentioned.)

464 CAMBRIAN BRACHIOPODA.

Obolus (Lingulella) rogersi WatcotT, 1898, Proc. U. 8. Nat. Mus., vol. 21, pp- 413-415. (Described and discussed
essentially as below as a new species.) :
Lingulella rogersi (Walcott), GraBAv, 1900, Occas. Papers Boston Soc. Nat. Hist., No. 4, vol. 1, pt. 3, pp. 624-625, PL.

XXXI, fig. 4. (Described and discussed.)

Obolus (Westonia) rogersi Waxcort, 1901, Proc. U. S. Nat. Mus., vol. 23, p. 691. (Merely changes generic reference.)

General form elongate ovate, with the ventral valve subacuminate and the dorsal valve
ovate in outline. There is considerable range of variation in the outline of the valves, owing
largely to distortion apparently produced by movement of the matrix. The convexity of the
valves is fairly strong and nearly the same in both, except that the dorsal valve curves more
abruptly inward toward the beak.

The outer surface of the shell usually adheres to the matrix, Thee in three specimens, portions
of it are preserved which show that it is of essentially the same character as that of Obolus
( Westonia) stoneanus (Pl. XXVIII). The surface is formed by very fine concentric lines and
strie of growth crossed transversely by strong, undulating, slightly lamellose lines (Pl. XLII,
figs. 2 amd 2d). When the outer layer is exfoliated the inner layers are marked by concentric
lines of growth and fine radiating striz. This is also the character of the inner surface, so far as
can be determined from the specimens in the collection. The shell is rather thick and built
up of a thin outer layer and several inner layers or lamellz, the latter becoming increasingly
numerous toward the front. The largest dorsal valve im the collection has a length of 13 mm.
with a width of 11 mm., and a smaller ventral valve with a length of 12 mm. has a width of
9mm. The dimensions of most of the specimens in the collection average less than those
here given.

The area of the ventral valve is relatively short for a species of this type. It is divided
midway, as seen in the cast, by a strong pedicle furrow. Owing to the imperfection of the mate-
rial, none of the specimens show flexure lines or strie of growth. The area of the dorsal valve is
short and extends but a short distance on either side of the median line. The cast of the interior
of the ventral valve is very much like that of the interior of Obolus cyane (PI. XVII). Ithas the
same median ridge and the transverse trapezoidal area which includes the central, middle lateral,
and outside lateral muscle scars. The main vascular sinuses are indicated by slight ridges
(Pl. XLII, figs. 2a and 2b). The cast of the interior of the dorsal valve shows a narrow median
septum, two central muscle scars of average size, situated a short distance back of the center of
the shell, and two small anterior lateral scars, located some distance in advance of the center,
which give an elongated visceral cavity somewhat like that of Lingulella hayesi (Pl. XXV) of
the Middle Cambrian and Obolus lamborni (Pl. XXII) of the Upper Cambrian.

Observations.—The external form of the more elongate specimens of this species is very
much like that of Lingulella acutangula (Roemer) (Pl. XVII). When compressed laterally it
occasionally has the form of Lingulella (Lingulepis) acwminata (Conrad). It is distinguished,
however, from all described species of Westonia known to me by its highly characteristic
surface ornamentation. Obolus (Westonia) stoneanus (Pl. XXVIII) has the same type of
surface, but it differs from the latter in beg a much more elongate shell.

The material described in this monograph was collected by Prof. N.S. Shaler and Mr. J. B.
Woodworth from the pebbles on the beach on the northern shore of Marthas Vineyard, Massa-
chusetts, and at several points along the shores of Narragansett Bay.

The first notice we have of these fossiliferous pebbles is that by W. B. Rogers, who [1861,
p- 389] announced the discovery, by Norman Easton, of pebbles carrying fossils of the Potsdam
fauna in the Carboniferous conglomerate north of Fall River, Massachusetts. In 1875 [p. 100]
Rogers announced the discovery of impressions, suggestive of the fossil Lingulas mentioned by
him from Fall River, in the pebbles in the conglomerate at Newport, Rhode Island. He
thought that the pebbles were derived from rocks probably closely connected in time with
the Braintree Paradorides zone.

Among the material sent by Professor Shaler I found the remains of a large Linguloid
brachiopod, which appears to be identical with Obolus (Lingulobolus) affinis (Billings), from
the Lower Ordovician rocks of Newfoundland. The material is somewhat imperfect, but I

ee eee,

OBOLIDZ. 465

do not know of any other large brachiopod of this type from the Cambrian or Ordovician rocks.
The reference to the Lower Ordovician is made by reason of the presence of this Lingulobolus.
The specific name is given for Mr. W. B. Rogers, who first called attention to the species.
ForMATION AND LOCALITY.—Lower Ordovician: (326) Limestone pebbles on the beach on the northern shore of
Marthas Vineyard; and (326a [Grabau, 1900, p. 613]) limestone pebbles in a Carboniferous conglomerate north of Fall
River, Bristol County; both in Massachusetts.
(848 [Rogers, 1875, p. 11, and U. S. Nat. Mus.]) Limestone pebbles on the beach near Newport and at several points

along the shores of Narragansett Bay, Rhode Island.
(114b) Sandstone 1 mile (1.6 km.) north of Lance Coye, Great Belle Island, Conception Bay, Newfoundland.

Oxsoius (WESTONIA) STONEANUS (Whitfield).
Plate XXVIII, figures 2, 2a-g; Plate XLIX, figures 2, 2a.

Lingula aurora var. Hawt, 1863, Sixteenth Ann. Rept. New York State Cab. Nat. Hist., pp. 127-128, Pl. VI, figs. 6-8.
(Described and discussed.)

Lingula aurora var. Hatt, 1867, Trans. Albany Inst., vol. 5, pp. 104-106, Pl. I, figs. 6-8. (Copy of preceding reference.)

Lingulella aurora var. Haut, 1873, Twenty-third Ann. Rept. New York State Cab. Nat. Hist., pp. 244-245, Pl. XIII,
fig. 5. (Mentions change of genus. Fig. 5 is drawn from the same specimen as Hall, 1863, Pl. VI, fig. 7.)

Lingulella stoneana Wurrrietp, 1882, Geology of Wisconsin, vol. 4, pp. 344-345, Pl. X XVII, figs. 6 and 7. (Charac-
terized and discussed as a new species.)

Lingulella stoneana Whitfield, Hat and CLrarKke, 1892, Nat. Hist. New York, Bbfacaillanny vol. 8, pt. 1, Pl. I], figs.
9-11. (No text reference. Figs. 9 and 11 are copied from Hall, 1863, Pl. VI, figs. 7 and 8, nespentiivelhy: and
fig. 10 from Hall, 1873, Pl. XIII, fig. 5.)

Lingulella stoneana Whitfield, WritEr, 1903, Geol. Survey New Jersey, Rept. Paleontology, vol. 3, p. 112, Pl. I, fig. 6
(Described and discussed. The specimen represented by fig. 6 is redrawn in this monograph, Pl. XLIX,
figs. 2 and 2a.)

Obolus (Westonia) stoneanus (Whitfield), Watcorr, 1901, Proc. U.S. Nat. Mus., vol. 23, p. 691. (Merely changes
generic reference.)

In form Obolus (Westonia) stoneanus (Pl. XXVIII) approaches quite closely to the more
rounded shells of Lingulella ampla (Owen), except that in the dorsal valve the posterior lateral
slopes are broadly rounded, giving a subelliptical outline to the valve. The original convexity
of the valves is not preserved, but it appears to have been moderate, like that of Lingulella
ampla. A large ventral valve from Prairie du Sac has a length of 15 mm., with a maximum
width of 11 mm. An associated dorsal valve, 10 mm. wide, has a length of 11.5 mm. The
surface of the shell is strongly characteristic. Itisformed by very fine concentric lines or striz of
growth crossed transversely by strong, undulating slightly lamellose lines (Pl. XXVIII, fig. 2d,
and Pl. XLIX, fig. 2a). The margins of the inner surface of the shell show fine radiating lines.
All of the large number of specimens in the collection are flattened in the shaly sandstone, and
there is usually little left of the substance of the shell to afford a basis for an opmion of the
form or thickness. A careful study of the material, however, leads to the conclusion that the
valves were moderately convex and comparatively thin. In casts of the interior the concentric
striz and transverse lamellose lines are almost invariably strongly marked, and no traces of
the interior muscle scars or markings are preserved.

The area of the ventral valve, as seen in a cast, is divided midway by the cast of the strongly
marked pedicle groove and, on each side and well out toward the margin, by the flexure lines.
The few strive of growth preserved cross the area parallel to its base. On the dorsal valve the
area is short, broad, and slightly arched forward near the center; the flexure lines are fairly
well preserved in a compressed cast of the shell. No muscle scars or vascular markings have
been observed on the interior casts of the ventral valve. A dorsal valve shows the central
muscle scars (h) and the base of the main vascular sinuses (vs) (Pl. XXVIII, fig. ih).

Observations.—This species was separated as a variety of Obolus (Westonia) aurora by
Professor Hall [1863, p. 127]. Later [1882, p. 344], Professor Whitfield, finding that its pecu-
liarities persisted in specimens found at localities where O. (W.) aurora did not occur, gave it
aspecific name. The peculiar surface ornamentation clearly distinguishes it from other species

62667°—vot 51, pr 1—12-_0.

466 CAMBRIAN BRACHIOPODA.

of the genus except O. (W.) aurora, from which it differs in having a more elongate form and in
the fact that the surface markings, though of the same type, vary in being much coarser and
in having longer undulations. (Compare Pl. XXVIII, fig. 2d, with Pl. XLVI, fig. ih.)

The form found by Stuart Weller [1900, p. 112] in the Upper Cambrian sandstones of north-
ern New Jersey is illustrated on Plate XLIX, figures 2, 2a.

The specific name was given for Mr. R. H. Stone [Whitfield, 1882, p. 345].

ForMATION AND LOCALITY.—Upper Cambrian: (85x) Upper beds of the “St. Croix sandstone’’ at Mazomanie,
Dane County; (81b) “St. Croix sandstone’’ near Devils Lake, Sauk County; (828m) sandstone 1 mile (1.6 km.) south
of Osceola, Polk County; (328f [Hall, 1863, p. 128]) sandstone at the falls of St. Croix River, Polk County; and (85 and
85s) 4 “‘St. Croix sandstone” at Prairie du Sac, Sauk County; all in Wisconsin.

(11c) Hardyston quartzite [Weller, 1903, pp. 110 and 112], O’Donnell and McManniman’s quarry, Newton, Sussex
County, New Jersey.

(327) Arenaceous limestone east of Gold Camp; (32%a) arenaceous limestone about 500 feet (152 m.) above the hase
of the Cambrian in McKinley Canyon; (327b) arenaceous limestone near the base of the section on the south side of
Cerro Cuchillo; and (827c) arenaceous limestone in the Caballos Mountains (exact locality unknown); all in the Caballos
Mountains, Sierra County, New Mexico.

Oxsotus (WestontA) THEMIS Walcott.

Plate XI, figures 2, 2a-c.

Obolus (Westonia) themis Waxtcort, 1905, Proc. U. 8. Nat. Mus., vol. 28, pp. 336-337. (Described and discussed as
below as a new species.)

General form subsemicircular, with the ventral valve subacuminate and the dorsal valve
broadly ovate in outline. Valves rather strongly convex. Surface of the shell marked by
strong concentric lines of growth with finer intermediate striz; in addition there are very fine,
irregular, raised, more or less transverse strize that imosculate, forming a minutely papillose
or granular surface much like that of Obolus (Westonia) ella (Pl. XLVII). It often occurs
that the outer surface has been removed by attrition in the sand, so that the shell has a smooth
polished surface. Owing to the condition of preservation the markings of the inner layers are
not preserved. The shell is strong and thick in advance of the center. It is made up of the
thin outer surface layer and several inner layers or lamell that in the posterior portions are
slightly oblique to the outer surface. After the shell has attaimed a size of 2 or 3 mm. the
lamellz are more oblique to the outer surface and form a thick, strong shell, the outer edges
of which often produce a rather rough surface. This is shown by the figures illustrating the
species.

The largest ventral valve in the collection has a length and breadth of 10 mm.; a dorsal
valve 10 mm. in leneth has a width of 11 mm. The only interior portions of the shell known
are on a fragmentary ventral valve in which the visceral area does not reach the center, and the
main vascular sinuses are about halfway between the center and the lateral margins of the
valve.

Observations.—The general form of the shell is much lke that of Obolus loperi (Pl. IX).
It differs from the latter in surface characters.

ForRMATION AND LOCALITY.—Middle Cambrian: (17c) Sandy limestone 235 feet (71.6 m.) above the “Tonto’’ sand-
stone, Grand View trail, north of Last Chance copper mine, south side of the Grand Canyon of the Colorado, Arizona.

OxsoLus (WESTONIA) WASATCHENSIS Walcott.

Text figures 41A—F, page 467; Plate XLIX, figures 5, 5a.

Obolus ( Westonia) wasatchensis Watcort, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, pp. 69-70, Pl. VIII, figs. 1 and la.
(Discussed as below as a new species. Figs. 1 and la are copied in this monograph as figs. 41A and 41D.)
This species is founded on some large shells that differ from Obolus ( Westonia) ella (Hall
and Whitfield) (Pl. XLVII) in attaining a larger size and greater proportional width and in

a 85s is the type locality, though the specimens in the United States National Museum to which that number is assigned were collected much
later than the type specimens.

OBOLID. 467

having the surface marked by radiating lines that extend from the umbo with a gentle curva-
ture toward the sides and front of the shell, so as to terminate at right angeles to the margin,
very much as in Obolus (Westonia) finlandensis (Pl. XLVIII, figs. 3 and 3a).

In the Blacksmith Fork section of the Middle Cambrian terrane in the Wasatch Moun-
tains of northern Utah O. (W.) wasatchensis occurs 1,590 feet higher in the section than
O. (W.) ella.

The specific name is derived from its occurrence in Wasatch Canyon, Utah.

FORMATION AND LOCALITY.—Middle Cambrian: (34u) Shales about 950 feet (289.6 m.) above the Cambrian quartzitic
beds, 2 miles (3.2 km.) southeast of Muskrat Spring, on the northwest face of Grantsville Peak, Stansbury Range,
Tooele County; and (38t) shale about 1,500 feet (457.2 m.) above the Brigham quartzite, 1 mile (1.6 km.) northwest
of Geneva (Copenhagen), east of Brig-
ham, Boxelder County; both in Utah.

(54q) Drift block supposed to have
come from the horizon of Locality 32x;
(82x) about 1,700 feet (518.2 m.) above
the Brigham quartzite [Walcott, 1908a,
p. 8], im shales correlated with the
shales forming 2d of the Bloomington
formation in Blacksmith Fork Canyon
[Waleott, 1908f, p. 195]; and (33)
about 2,300 feet (701 m.) above the
Brigham quartzite; all in Wasatch
Canyon, east of Lakeview Ranch, 5
miles (§ km.) north of Brigham, Box-
elder County, Utah.

(54h) About 3,140 feet (957.1 m.)
above the Brigham quartzite [Walcott,
1908a, p. 8] and 1,050 feet (320 m.)
below the Upper Cambrian in the lime-
stones forming la of the Bloomington
formation [Walcott, 1908f, p. 194]; and :
(54k) about 2,100 feet (640 m.) above FieurE 41.—Obolus (Westonia) wasatchensis Walcott. A, Elongate ventral valve, the type.

the Lower Cambrian and 2,100 feet specimen (U.S. Nat. Mus. Cat. No. 51733a). 3B, Interior view of an elongate ventral valve
“a U.S. Nat. Mus. Cat. No.51737a). C, Interior of a broken, flattened ventral valve (U.S. Nat.

640 m.) below the Upper Cambrian ( 2 9

( th " lien 8 F aoa the Bl Mus. Cat. No. 51734b). D, Exterior of dorsal valve (U. S. Nat. Mus. Cat. No. 51734a).

an € shales rms @ S eMoloiail= y, Interior of a flattened dorsal valve (U. S. Nat. Mus. Cat. No. 51734c). F, Interior of a

ineton formation [Walcott, 1908f, p. dorsal valve (U. S. Nat. Mus. Cat. No. 51734d).

195]; both in Blacksmith Fork Canyon, The specimens represented by figures 41A and 41B are from Localities 54q and 55d, respec-

about 10 miles (16.1 km.) east of Hy- tively; and those represented by figures 41C-F are from Locality 54k. Figures 41A and 41D are
rum, Cache CG ounty Utah copied from Walcott [1908d, Pl. VIII, figs. 1 and 1a, respectively].
? ? p

(55d) About 2,000 feet (609.6 m.) above the Cambrian quartzitic beds, in a shale which is probably to be referred
to the Bloomington formation [Walcott, 1908a, p. 7], on the south side of Twomile Canyon near its mouth, 2 miles
(3.2 km.) southeast of Malade, Oneida County, Idaho.

OgpoLus (WESTONIA) WIMANI Walcott.

V Plate XLVIII, figures 5, 5a—b.

Lingula? sp. No. 1, Wrman, 1902, Bull. Geol. Inst. Univ. Upsala, vol. 6, pt. 1, No. 11, p.51, Pl. II, fig. 36. (Locality
mentioned.)

Lingulella ? sp. No. 1, Wran, 1902, idem, p. 52, Pl. II, fig. 30. (Locality mentioned. The specimen represented by
fig. 30 is redrawn in this monograph, Pl. XLVIII, fig. 5.)

Lingulella? sp. No. 2, Wan, 1902, idem, p. 52, Pl. II, fig.31. (Locality mentioned. The specimen represented by
fig. 31 is redrawn in this monograph, Pl. XLVIII, fig. 5a.)

Tingulella? sp. No. 7, Wiman, 1902, idem, p. 52, Pl. Il, fig.32. (Locality mentioned. The specimen represented by
fig. 32 is redrawn in this monograph, Pl. XLVIII, fig. 5b.)

Obolus ( Westonia) wimani Waucotr, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 337. (Discussed essentially as below as a
new species. )

The general form of this species is not unlike that of Obolus ( Westonia) bottnicus (Wiman)
(Pl. XLVIID). The cardinal slopes of the ventral valve are more rounded, which makes the
valve broader near the center. All of the specimens are also smaller. The surface markings

468 CAMBRIAN BRACHIOPODA.

are of the same character as those of Obolus ( Westonia) finlandensis Walcott (Pl. XLVIII) and
O. (W.) bottnicus.

It is not improbable that with the discovery of a large series of specimens the three species
may be combined, or O. (W.) bottnicus and O. (W.) wimani placed as varieties of O. ( W.)
jinlandensis.

For reference to the geological horizon of bowlders on Eggegrund Island, similar to the
ones containing this species, see description of O. ( W.) bottnicus, page 454.

The specific name is given for Dr. Carl Wiman, of the University of Upsala.

ForMATION AND LOCALITY.—Middle? Cambrian: (311c, 311g, and 311i)¢ Drift bowlders of bituminous sandstone, Nos.
7, 16, and 27 [Wiman, 1902, p. 57), on Biludden, about 20 miles (82.2 km.) east of Gefle, Province of Gefleborg, Sweden.
(811t) Drift bowlder of mottled calcareous sandstone [Wiman, 1902, p. 57], at Ofverby, parish of Jomala, Aland
Island, Finland, Russia.
Osotus (WESTONIA) sp. undt. a.

Fragments of a species of Obolus with a very minutely reticulated surface occur in associa-
tion with Cyrtoceras cambria Walcott and suggest Obolus ( Westonia) ella, except that the surface

ornamentation is so minute that it can only be seen with a strong lens. The fragments indicate
a shell about the size of O. (W.) ella.

ForMATION AND LOCALITY.—Upper Cambrian: (C56) Lower part of Chaumitien limestone, 25 feet below the top
of Pagoda Hill [Blackwelder, 1907a, p. 42 (part of last list of fossils)], 1 mile (1.6 km.) west of Tsinan, Shantung,
China. ‘

Oxsotus (WexsTontA) sp. undt. b.

Fragments of a shell showing the characteristic surface ornamentation of Westonia occur
in the Ordovician limestone, Eureka district, Nevada. The shell must have been at least
as large as Obolus (Westonia) stoneanus (Whitfield), but the material is too imperfect for
identification.

FORMATION AND LOCALITY.—Passage beds between the Upper Cambrian and the Ordovician: (205) siliceous
limestone on Roundtop Mountain, Eureka district [Hague, 1892, Atlas], Eureka County, Nevada.

Genus LINGULELLA Salter.
[Lingula.]

Tellinomya McCoy [not Hatt], 1854, British Paleozoic Fossils, p. 274. (Described from distorted specimens of Lin-
gulella davist (McCoy).)

Lingulella Saurer, 1866, Mem. Geol. Survey Great Britain, vol. 3, p.333. (Described and discussed as a new genus.)
“The name Lingulella was first introduced about 1861, with the late Dr. 8. P. Woodward’s full consent; and
the name appears at page 9 of Sir Roderick Murchison’s address to the geological section of the British Asso-
ciation, Manchester, 1861,’ but was not described (see Davidson, 1866, p. 55). ,

Lingulella Salter, Davrpson, 1866, British Fossil Brachiopoda, vol. 3, pt. 7, No.1, p.55. (Original description copied
and Lingulella discussed as either a genus or subgenus.)

Lingulella Salter, Davipson, 1868, Geol. Mag., vol. 5, p. 304. (Genus discussed.)

Lingulella Salter, Dau, 1870, Am. Jour. Conchology, 2d ser., vol. 6, pt. 2, pp. 153 and 159. (Described.)

Lingulella Salter, Mpex, 1871, Proc. Acad. Nat. Sci. Philadelphia for 1871, vol. 23, pp. 186-187. (Notes on genus in
discussion of “‘Lingulella lamborni.”’)

Lingulella Salter, Dat, 1877, Bull. U. S. Nat. Mus. No. 8, p. 44. (Mentioned.) ‘

Lingulella Salter, Zrrreu, 1880, Handbuch der Palzontologie, Bd. 1, Abth. 1, pp. 663-664. (Described in German.)

Lingulella Salter, SatrpR and Erueripes, 1881, Mem. Geol. Survey Great Britain, vol. 3, 2d ed., p. 537. (Copy of
Salter, 1866b, p. 333.) s

Lingula (Lingulella) Salter, OnHLERT, 1887, Manuel de conchyliologie, by Fischer, p. 1261. (Described in French.)

Lingulella Salter, Bornemann, 1891, Nova Acta Acad. Czs. Leop. Carol. Germanicze Naturee Curiosorum, Bd. 56,
No. 3, pp. 485-437. (Discussed in German.)

Lingulella Salter, Hatt and Ciarkx (in part), 1892, Eleventh Ann. Rept. State Geologist New York for 1891, pp. 232-233.
(Described. Lingulella davisi is given as the type, but as a generic illustration Botsfordia cxldta is figured on
TEAL, TL.)

Lingulella Salter, Hatt and Crarxke (in part), 1892, Forty-fifth Ann. Rept. New York State Museum for 1891, pp.
548-549. (Copy of preceding reference.)

a@ 311c is the type locality.

OBOLIDA. 469

Lingulella Haru and Ctarxe (in part), 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, pp. 55-59. (Original
description copied and genus discussed. Lingulella davisi is given as the type, but ficures of Obolus ( Westonia)
ella accompany the text and as a generic illustration Botsfordia czlata is figured on Pl, II. Species belonging
with other genera are also mentioned as belonging to Lingulella.)

Obolus (Buobolus) Mrcxwrrz (in part), 1896, Mém. Acad. imp. sci. St.-Pétersbourg, 8th ser., vol. 4, No. 2, p. 129.
(Described in German.)

Obolus (Lingulella) (Salter), Watcorr, 1898, Proc. U. S. Nat. Mus., vol. 21, pp. 390-392. (Discussed.)

Lingulella Salter, MarrHEew, 1899, Bull. Nat. Hist. Soc. New Brunswick, vol. 4, pt. 3, No. 18, p. 201. (Characterized
in discussion of Palxobolus, see p. 471, for copy.)

Obolus (Lingulella) (Salter), Waxcorr, 1901, Proc. U. S. Nat. Mus., vol. 23, p. 683. (Characterized. )

Eoobolus MarruEw, 1902, Trans. Roy. Soc. Canada for 1902, 2d ser., vol. 8, sec. 4, No. 3, p.97. (Characterized without
reference to Mickwitz and without any indication of the fact of its being intended as a new subgenus; see
Matthew, 1903, p. 135.)

Lingulella Salter, MatrHew, 1902, idem, p. 103. (Nova Scotia representatives mentioned.)

Leptobolus Marraew [not Haut], 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, pp. 105-106.
(Described, see p. 472 for copy.)

Lingulella Salter, Matrnew, 1903, idem, p. 116. (Discussed.)

Obolus (Hoobolus) Matruew, 1903, idem, p. 185. (Characterized as a new subgenus.)

Lingulella Salter, Deveapo, 1904, Communicagdes Commissao Servigo Geol. Portugal, tome 5, fasc. 2, p. 367. (Dis-
cussed in French.)

Not Lingulella Grapav and Sumer, 1907, North American Index Fossils, vol..1, p. 192. (Described, but one of the
species referred to belongs with Obolus (Westonia) and the other is the type of that subgenus.)

Lingulella Salter, Watcort, 1908, Smithsonian Misc. Coll., vol. 53, No. 4, Pl. XI, and pp. 142 and 144. (Classification
of genus.) ‘

Type of genus.—Lingula davisi McCoy.

Valves subequal, equilateral; elongate ovate, broad ovate, or subtriangular in outline.
Ventral valve usually subacuminate, with a distimct area, pedicle groove, and flexure lines.
Dorsal valve somewhat shorter, less acuminate, and with a less clearly marked pedicle groove
on the shorter area. Beaks terminate at the margin of the areas, which are usually in the
plane of the margins of the valves; the areas, which vary in size and shape in the different
species, are usually more or less triangular; in the ventral valve they may be so shortened and
arched as to nearly lose this marked form; the areas of the dorsal valve also vary in their form
length, and extension on the cardinal slopes.

Shell substance caleareocorneous; structure consists of a thin outer surface layer and
numerous inner layers or lamelle that are subparallel to the surface over the posterior portions
of the shell and more or less oblique to it over the central, lateral, and anterior portions; the
short oblique layers usually form the inner flattened rim of the valves which is frequently seen
in the casts (Pl. XVII, fig. 1i). Surface of shell marked by fine concentric striz and lines of
growth, and in some species finely mosculating, lamellose striz; also, in most if not all species,
radiating striz and lines.

The visceral area (splanchnocele [Mickwitz, 1896]) is usually confined to the central and
posterior portions of the ventral valve, but it may extend far into the brachial area (brachio-
cole [Mickwitz, 1896]) (Pl. XVII, fig. 1c); in the dorsal valve it extends farther forward than
in the ventral valve of the same species; in both valves it may range from the posterior third
of the shell forward to the anterior third, and in the dorsal well into the latter; m both valves
the visceral area extends back to the base of the areas where it is bounded exteriorly by the
flexure lines (lines of folding of the area lamella).

A narrow median ridge or septum is frequently observable in the dorsal valve, but with the
exception of what may be considered as indicating its probable presence in one specimen of a
ventral valve of Lingulella davisi (McCoy) (PI. XX XI, fig. 6f), no traces of a septum have been
observed in the ventral valve of any of the species that I have studied. The main vascular
sinuses vary in size, direction, and length in the various species; in all they begin in front of
the area at the median line and extend forward and outward across the parietal band into the
central-lateral and anterior parts of the brachioccele. The impressions of the secondary vascular
canals are rarely preserved, but the few traces observed indicate that they were numerous and
extended toward the peripheral canal and into the middle of the shell in the direction neces-
sitated by the arrangement of the main sinuses and the boundaries of the visceral area.

470 CAMBRIAN BRACHIOPODA.

In the anterior portion of the visceral area of the dorsal valve of some species the ‘‘heart-
shaped pit’’ of Obdolus is distinctly marked (Pl. XVII, fig. 1f). It is rarely so well shown,
although its anterior outline is preserved in nearly all species whose interior characters are well
marked. A median ridge may or may not be present in the interior of the dorsal valve.

The preservation of all vascular markings depends largely on the thickness of the shell,
being rarely seen in thin shells and often found in thick ones.

There are six pairs of muscle scars that have been observed, in addition to the pedicle scar
(m) which is situated on the ventral valve between the two scars (gg) left by the divided umbonal
muscle close to the area; on the dorsal valve the smgle umbonal scar (g) is just in advance of
the base of the area. The central scars (h) are usually situated about the center of the dorsal
valve a short distance each side of a median septum; in the ventral valve they are inclosed
in a trapezoidal area (c), with the scars of the outside and middle lateral muscles, on each
anterolateral side of the heart-shaped area (x). The transmedian scars are shown as one
scar on each side a little in advance of and on a line with the flexure lines of the area; the
variation in their relative position in the two valves and in various species may best be under-
stood by studying the illustrations and descriptions of species. The scars (k) of the middle
lateral muscles are inclosed within the area (x) with the central and outside laterals; in the
dorsal valve they blend with those of the outside laterals (1) in advance and a little outside of
the transmedian scars (i). As previously stated, the scars of the outside lateral muscles in the
ventral valve are combined with the central and middle laterals, while in the dorsal valve they are
united with the middle lateral muscles. The scars of the anterior lateral muscles (j) of the
ventral valve are usually so closely united with those of the transmedians (1) that it is only in
unusually well-preserved specimens that the two scars can be differentiated; in the dorsal
valve they are more or less in advance of the centrals, and divided by a narrow median
septum or ridge; they may be situated a little back of the center of the valve or at any distance
between that and a short distance from the frontal margin of the shell. In both valves the
scar of the parietal band closely circumscribes all muscle scars externally, crossing the main
vascular sinuses and terminating at the base of the flexure line of the area.

The principal forms of Lingulella may be grouped under five divisions by the outlines of
the ventral valve.

Acuminate: Ovate-elongate
Lingulella Peroriouia (Pl. XX1). Lingulella bella (Pl. XTX).
L. acutangula (Pl. XVII). Ovate-quadrangular:
LI. manticula (Pl. XX). Lingulella mosia (Pl. XVIII).
LZ. nanno (Pl. XXIV). L. winona (Pl. XVIII).
Subacuminate: Subtriangular:
Lingulella davisi (Pl. XXX1). Lingulella auga (Pl. XXIV).

Intermediate forms are illustrated by Lingulella martinensis (Pl. XX XVIII), which is
rounded subtriangular and acuminate, and L. phaon (Pl. XXVI), which is both acumimate and
subacuminate.

The outline, relative size, and position of the visceral areas (splanchnoceeles) are exceed-
ingly variable.

In Lingulella oweni (Pl. XVII) the area is very short, while in L. acutangula (Pl. XVID),
L. perattenuata and L. similis (Pl. XXI), L. punctata (Pl. XX), and L. radula (Pl. XLYV) it is
elongate. The narrow type of visceral area in the dorsal valve is seen in Lingulella acutangula
(Pl. XVII), L. hayest (Pl. XXV), L. similis (Pl. XX1), L. manticula (Pl. XX), L.leos (Pl. XXIV),
L. ampla (Pl. XXVIII), and L. radula (Pl. XLV).

The surface characters vary from the almost smooth and highly polished Lingulella nanno
(Pl. XXIV), on which only the faintest traces of radiating striz and depressed rounded lines
of growth are visible, to shells with strong concentric striz and lines of growth, Lingulella auga
(PI. XXIV). Whenever the surface of the shell is sufficiently well apesermel to permit close
examination radiating striz have been observed.

Observations.—Prior to the investigation of the material described and illustrated m this
monograph,? the data relating to Lingulella were too meager to permit detailed comparison with

a Announced in a preliminary paper: Proc. U. S. Nat. Mus., vol. 21, 1898, p. 390.

;
:
y

OBOLIDA. 471

other genera. The presence of a peculiar central channel in the cardinal area was the only
character of importance observed by Davidson [1866, p. 55] that served to distinguish Lin-
gulella from Lingula. In the original description, Salter [1866b, p. 333] calls attention to the
resemblance of the muscular scars of Lingulella to those of Obolus, but he considers that the
difference in relative position is sufficient to distinguish the two genera. Attention is also called
[Salter, 1866b, p. 333] to Obolella Billings, and to the fact that the later figures of Billings “‘show
a very different set of muscular scars.’’ Davidson had the same material that Salter had and
more, but was unable to find any satisfactory interiors, and hence left the genus as doubtful,
evidently considering it as closely related to Lingula.

Mickwitz met with the same difficulty as Davidson, in having unsatisfactory material upon
which to base an opinion. After stating [1896, p. 126] that Obolella Billmgs would probably
have to make room for the genus Obolus Hichwald, he says: ‘‘Whether Lingulella Salter will
share the same fate I will not venture to predict with the same degree of certainty, since the
diagnosis and figures are even more imperfect than in Billings’s genus.”

When in Wales, in 1888, I made a small collection of Lingulella davisi (McCoy) at thetype
locality at Portmadoc, and later Mr. G. J. Williams sent me a number of fine specimens for
study. With this material, supplemented by a beautiful series of specimens of a number of
American species, it has been possible to obtain a clear conception of Lingulella and its relations
to Obolus, Obolella, Schmidtia, Lingulobolus, Lingulepis, and Lingula.

The memoir of Mickwitz [1896] gave the genus Obolus a position that it had not held prior to
his very thorough investigation. With his descriptions and plates and a fine suite of specimens
worked out from material very generously given me by Dr. Fr. Schmidt, I have been able to
make a series of comparisons with Lingulella that at times has led me almost to doubt the
advisability of characterizing Lingulella as generically distinct from Obolus. This distinction is
now based on the more elongate form of most of the species of Lingulella, and the greater thick-
_ ness of the shell of the typical forms of Obolus. There are differences in the position, size, and
form of the muscular scars, visceral area, and vascular canals of Obolus and Lingulella, but they
are not greater than those between different species referred to Lingulella. The same general
arrangement of muscle scars prevails, but on comparing the interior of the dorsal valve of
Lingulella davisi (McCoy) (Pl. XXXI, fig. 6e) with that of Lingulella acutangula (Roemer)
(Pl. XVII, fig. 1h) or Lingulella ampla (Owen) (Pl. XXVIII, fig. 1h) we find as great variation
as when the comparison is made with the dorsal valve of Obolus (Pl. VII, figs. 6-9). The same
is true of the ventral valve, although the means of comparison are in this case not so good.
One of the oldest species of Lingulella, L. granvillensis Walcott (Pl. XXII) of the upper
Olenellus zone, has the outline of Obolus (Schmidtia) celatus Volborth, and the interior markings
of the ventral valve are also of the same type. Lingulella acutangula (Roemer) (Pl. XVII,
fig. 1f) has the heart-shaped pit so characteristic of Obolus (Pl. VII, figs. 1-4) and the arrange-
ment of the muscular scars is essentially as in Obolus, but the outline of the valve is much more
elongate. Lingulella davisi (McCoy) and Lingulella ampla (Owen) vary decidedly from Obolus
in the interior markings, but not more than Lingulella ampla differs from Lingulella acutangula.
The variations are so well shown by the figures on the plates that detailed comparisons will
not be entered upon.

Matthew [1899b, p. 201] proposed to distinguish Obolus from Lingulella by its—
roundness of outline, short cardinal area and depressed beaks, advanced position of muscle scars in the valve, and
strong arch of the vascular trunks in the ventral as well as the dorsal valve. There is, however, a more important
distinction, which, in consequence of imperfect preservation of the valves, can seldom be observed; that is, the position
of the secondary muscles of the central group in the ventral valve, as compared with the great muscle of that group.
In Obolus they are lateral, but in Lingulella anterior to the great muscle. This showsa radical difference of structure
between the two genera.

I am not able to recognize as constant the characters mentioned by Matthew, owing to
the great variation in the large group of species referred to Obolus and Lingulella. The data
for a clear distinction of the two, Obolus and Lingulella, are still too limited for more than an
arbitrary reference of Lingulella to a generic place in relation to Obolus. This is particularly

472 CAMBRIAN BRACHIOPODA.

the case with the position of the muscle scars of the ventral valve to which Matthew refers.
The central muscles of the ventral valve of Obolus vary greatly in the position of the poimts of
attachment; this isshown by Plate VII, figures 1-13, for Obolus apollims. The scarsof the central
muscles of Lingulella are rarely preserved so that they can all be identified; in one species,
Lingulella acutangula (Pl. XVII, figs. le and 1g), they appear to be arranged as in Obolus
apollinis. The same is true for Obolus ( Westonia) escasona (Matthew) (Pl. XLIX, fig. laa)._

The genus Schmidtia Volborth is made a subgenus of Obolus by Mickwitz [1896, p. 25].
A comparison of typical specimens of Obolus (Schmidtia) celatus Volborth and Lingulella
davisi (McCoy) leads to the view that Schmidtia is identical with Lingulella except that Lin-
gulella is a radially striated shell and Schmidtia is not. I did not fully appreciate this distine-
tion when writing a preliminary notice [1898, p. 392] of the study of Lingulella and hence
referred to Schmidtia as a synonym of Lingulella.

Any extended comparison with Obolella is unnecessary, as it is a thick, round-ovate shell
with a cardinal area and pedicle opening unlike Lingulella or any of the subgenera of Obolus.
Lingulobolus has the same arrangement of muscle scars as Lingulella, but dite in the greater
thickness of the shell in both valves. Lingulepis is scarcely more than a very acuminate form
of Lingulella with the area and visceral cavity of the ventral valve modified in shape to meet
the extreme elongation of the posterior portion of the valve.

That Lingulella is closely related to Lingula is seen at once by comparing the markings
on the interior of the two shells.

Under observations on Obolus (p. 375) the differences between Obolus and Lingula have
been stated. Lingulella differs from Lingula im the same manner as Obolus in haying its visceral
area continued back to the posterior margin of the interior of the valves, but it has the same
general form as Lingula. Without the interior of the valves for comparison it would be very
difficult to determine that many of the Cambrian species were not true species of Lingula.

Matthew [1903, p. 105] refers a group of small shells heretofore placed under Lingulella
to the Ordovician genus Leptobolus of Hall. He says:

Such forms have usually been included in Lingulella, but in addition to their minute size they are separated
from that genus by important characters.

These little shells have thin test, weak umbones; vascular trunks are situated near the lateral margins, and both
the central and lateral muscles in both valves are advanced far toward the front of the valves.

As a result of the examination of the types of the Ordovician species of Leptobolus I find
that they have quite strong, thick shells in proportion to their size, quite as much so as the
young shells of species of Lingulella that acquire thickened shells as they attain their full
growth. The vascular trunks are well out toward the margin, but this feature also occurs im
large forms of Lingulella, as indicated in the table under Obolus (p. 377). The position of the
central and lateral muscle scars is also too variable a character to afford a basis for generic
reference. Leptobolus is marked by a peculiar visceral area in the ventral valve unknown in
any Cambrian shell, and the bifurcation of the strongly marked ridges of the path of advance
of the central and lateral muscle scars in the dorsal valve is a distinguishing character not
found in the Cambrian shells referred to Leptobolus. The Cambrian forms referred to Lepto-
bolus by Matthew [1903] are: L. atavus, L. atavus wmsule, L. atavus tritavus, L. collicia, L.
collicia collis, L. flumenis, L. gemmulus, L. ef. linguloides, and L. torrentis.

If the above species are included in a distinct genus, several others should go with them,
notably: Lingulella ferruginea Salter (Pl. X XIX), L. lepis (Salter) (Pl. XX XT), and L. cama
(Walcott) (Pl. XX XY).

One of the oldest species known of the genus Lingulella, Lingulella schucherta (Walcott)
(PI. XXII, fig. 6), is in all respects, so far as can be determined from the material, a true Lingu-
lella. The shell is phosphatic, relatively thin, elongate, resembling in this respect Lingulella
acutangula (Roemer) (Pl. XVII). From this it appears that we have in the Olenellus fauna
of the Lower Cambrian, associated with Obolella, a typical representation of the genus Lingu-
lella. This association shows that the differentiation in the group of brachiopods represented
by Lingula and Obolella, or the Lingulide, had advanced a long way before the period in Lower

OBOLIDA. : 473

Cambrian time represented by the fauna at Troy, New York. It is to be borne in mind that
tke fauna at Troy was collected both from stratified and conglomerate limestones. On this
account it is not practicable to state that all the species from either are from the same geologic
horizon, but Lingulella schuchertti (Walcott) (Pl. XXI) and Obolella crassa (Hall) (PI. LIV)
occur in the same pieces of limestone. Lingulella granvillensis Walcott (Pl. XXII) occurs at
numerous places in Washington County, New York, in strata near the top of the Lower Cambrian
zone. Lingulella nathorsti Linnarsson (Pl. XX XI, figs. 1, la—b) occurs in the Holmia kjerulfi zone
of Sweden. It has nearly the outline of Lingulella acutangula (Roemer) in some examples of
the ventral valve. (Compare Pl. XXXI, fig. le, with Pl. XVII, fig. 1a; and Pl. XXXI, fic.
la, with Pl. XVII, figs. 1h—k; also fig. 1 on each of the two plates.) Lingulella delgadoi Walcott
(Pl. X XTX, figs. 6 and 6a) from the Olenellus zone of Portugal is, from our present knowledge
of it, a true Lingulella.

Matthew [1903, p. 109] in speaking of the growth of Lingulella and allied forms, speaks of
a law that the young shells are, often round and the adults more elongate. This is in accord
with the view that the protegulum of all forms of the Atremata is semicircular or semielliptical.
In Lingulella (Lingulepis) gregwa (Matthew) (Pl. XLIV) and L. (L.) exigua (Matthew) (PI.
XLII) the young shells are more elongate than the adult, owing to the broadening of the
anterior portions of the valves as they increase in size.

LTingulella? paliformis (Hall and Clarke, 1892c, Pl. II, figs. 6-8] has the form of some of
the more acuminate species of Lingulella, but from a study of the type specimens I am led to
conclude that the material is too limited to decide the true generic relations of the species.
The area of the dorsal valve is like that of Lingulella, but the only specimen showing the area
of the ventral valve suggests that the pedicle furrow was confined to the dorsal valve. Nothing
is known of the interior markings of either valve.

The vertical range of iEjagoalelint is from the upper horizon of the Olenellus or Lower Cambrian
fauna to the summit of the Cambrian and into the Ordovician fauna. One of the oldest known
species is Lingulella schucherti (Walcott), found in the limestone conglomerate at Troy, New
York, in association with Obolella crassa (Hall), Bicia gemma (Billings), Elliptocephala asa-
phoides Emmons, ete. Lingulella granvillensis Walcott, which is associated with Olenellus
in the strata referred to the upper portion of the Olenellus zone, L. nathorsti Linnarsson of the
Holmia kjerulfi zone of Sweden, and L. delgadoi Walcott are found in association with Olenellus.
The greatest development of the species is in the Middle and Upper Cambrian, only a few forms
continuing on into the Lower Ordovician.

The small Lingulella desiderata ranges from the base of the Middle Cambrian in the Cor-
dilleran region to the Ordovician. There may be specific differences, but in the large amount
of material now available for study there are none that appear to be of specific importance.
Lingulella isse also has a great vertical range.

Lingula attenuata Sowerby [Davidson, 1866, p. 44, Pl. III, figs. 18-27] has the form of Lin-
gulella and may possibly be a survival into the Middle Ordovician of a species of the genus. We
do not have sufficient data to know whether the interior markings of the valves are more like
those of Lingula or Lingulella.

Of the 77 species and 4 varieties from the Cambrian referred to Lingulella in this monograph,
5 species occur in the Lower Cambrian, 46 species and 1 variety in the Middle Cambrian, 35
species and 3 varieties in the Upper Cambrian, 6 species in the passage beds between the Cam-
brian and the Ordovician, and there are 13 species from the Ordovician. Of the Middle Cam-
brian species 13 pass up into the Upper Cambrian, of which two are found in the Ordovician. Two
species pass from the Upper Cambrian to the Ordovician and two from the Upper Cambrian
to the passage beds.

The range of all known species is given in the tables of genera and species (pp. 98-113).

Subgenera of Lingulella.—Leptembolon Mickwitz [1896, p. 199] is rather difficult to charac-
terize. Mickwitz [1896, p. 199] says of it:

The subgenus Leptembolon is based ona species of Obolus which externally resembles Lingula very closely, and
in fact was regarded as such by earlier authors [Schmidt, Fr., 1881, p. 17]. The specimens of the internal surfaces

474 CAMBRIAN BRACHIOPODA.

of the valves, however, showed, together with some suggestions of the last-mentioned genus (Lingula), unmistakable
marks of the genus Obolus, so that the species, which would not be assigned to any of the other groups, had to be ranked
in a special subgenus of Eichwald’s.genus.

Type.—Obolus (Leptembolon) lingulzformis Mickwitz (Pl. XIV, figs. 5, 5a—b).

Lingulepis Hall [1863, p. 129] is a Lingulella-like shell with the ventral beak much atten-
uated. Type: Lingula acuminata Conrad.

For the species hitherto referred to Lingulella that are now referred to other genera or
subgenera see pages 58-62.

LINGULELLA ACUTANGULA (Roemer).
Plate XVII, figures 1, la-o.

Lingula acutangula Rozmsr, 1849, Texas, p. 420. (Described in Latin and discussed in German as a new species.)

Lingula acutangula Rormmr, 1852, Kreidebildungen von Texas, p. 90, Pl. XI, figs. 10a—b. (Described in Latin and
discussed in German.)

Lingulepis acutangulus (Roemer), ScHucHERT, 1897, Bull. U.S. Geol. Survey No. 87, p. 259. (Merely changes generic
reference.

Obolus eee acutangulus (Roemer), Waxcort, 1898, Proc. U. S. Nat. Mus., vol. 21, pp. 392 and 394; Pl. XX VII,
fig. 6; Pl. XXVIII, figs. land 2. (Mentioned in the text in discussion of Lingulella. Figs. 6, 1, and 2 are repro-
duced in this monograph, Pl. XVII, figs. 1c, 14, and 1h, respectively.)

General form elongate ovate with the ventral valve subacuminate and the dorsal valve
ovate in outline. When the ventral valve is slightly compressed the cardinal slopes are often
crushed down over the area about the pedicle groove, so as to make the outline of the valve more
acuminate. This appears to be the case with the type figure of Roemer, and it is partly shown
by Plate XVII, figure le. There is considerable range of variation in the outline of the valves
(Pl. XVII). The convexity of the two valves is fairly strong, and it is nearly the same in each,
except that the dorsal valve curves inward more rapidly toward the beak. A ventral valve
9 mm. in length has a convexity of 1.25 mm., and a dorsal valve 10 mm. long arches 1.5 mm.
above the plane of the margin.

Surface of the shell marked by radiating and concentric striz and lines of growth. The
radiating striz are usually indistinct, but in a number of shells they are well marked or inter-
rupted somewhat by irregular rounded lines that alternate, blend, and disappear without any
apparent system (Pl. XVII, fig. 11). The concentric striz are fine, usually having an unbroken
curvature, but in some instances they are broken into short undulations, such as characterize
the surface of several other species of Lingulella. In some examples the undulations are close
and pronounced, and form a fine broken reticulation that is discernible only with a strong mag-
nifying glass. When the outer layer of the shell is partly exfoliated the radiating strize appear
as sharp, clear-cut lines, but they do not extend to the inner surface of the shell (PI. XVII, fig. 11).
The interior surface is usually marked by strong puncte which vary greatly in Pine and
arrangement. This is illustrated by the casts of the interior of several shells, where the puncte
are represented by papillz. On figure 1c the papille are large and somewhat scattered, while
in figure 1a they are smaller and Symamgad in concentric limes quite to the edge of ne shell.
In the dorsal valve the punctz are not quite so strong and they do not extend out to the margin
(Pl. XVII, figs. 11, 1j, and 1k); in specimens shovaine: the interior scars and markings the puncte
are less numerous (figs. 1f, 1h, and 1)).

The shell is thicker than in most species of the genus, in this respect resembling in a modified
degree the type of Obolus, O. apollinis Eichwald. The shell is formed of a thin outer layer
and several thinner layers or lamelle that are slightly oblique to the outer layer (fig. 1m), a
structure quite similar to that of the shell of the recent Lingula anatina Bruguiére.

The longest ventral valve in the collection has a length of 14 mm., and a maximum width
of 10 mm. Roemer’s figure [1852, Pl. XI, fig. 10] is larger, 18 mm. by 13 mm. The average
length of the ventral valve is from about 8 to 10 mm., and of the dorsal valve 6.5 to 8.5 mm.
The relative dimensions of the two valves may be seen by a comparison of figures 1 and i,
Plate XVII.

OBOLIDA. 475

As determined by a study of interior casts, the plane of the cardinal area of the ventral
valve coincides near its edges with the edge of the shell, rising slightly toward the deep, rounded
pedicle furrow. The area is divided at the center by the pedicle furrow, and toward its margins
by elevated lines, or extremely narrow ridges, that extend from the apex with a slightly outward
curvature to the base of the area (the flexure marks of the area parallel with its base); they
are rounded and strong in the pedicle groove, sharp and crowded on the lateral slopes; they
cross the pedicle groove transversely, slope forward across the central spaces (splanchnocele
of Mickwitz [1896, p. 116]) curve almost backward in the flexure lines and slope forward at a
low angle across the lateral spaces (pleuroceele of Mickwitz [1896, p. 116]). The area forms a
thin shelf between the pedicle groove and the lateral margins, the undercut extending far back
under the area. This is shown in the cast by a thin projection of the embedding rock over the
area (Pl. XVII, figs la, 1c, and 1f), where the broken edges remain. The area of the dorsal
valve is lower and less prominent; the striz of growth cross it parallel to the anterior margin,
being interrupted by the flexure lines, which are but slightly indicated on most specimens.
The shallow furrow, corresponding to the pedicle furrow of the ventral valve, usually extends
across the space between the flexure lines. The pedicle groove on the ventral valve is deep,
narrow, and strongly defined, tapermg very gradually from the anterior end toward the beak.

The cast of the visceral cavity (v), mcluding the heart-shaped pit (x) of the ventral valve,
is shown by Plate XVII, figures 1a, Ic, 1f, and 1g, the latter particularly well by figure 1f,
where it strongly resembles the same space in Obolus apollinis Kichwald. There are no traces
of a median septum in the ventral valve; in the dorsal valve it is shown in the casts as a very
narrow, clearly defined, sharp depression (s) extending a short distance back of the central
muscle scars, in some specimens, and forward nearly to the anterior lateral scars (Pl. XVII,
figs. 1h and 1j).

The muscle scars are finely shown im casts of both valves. The umbonal scar (ge) of the
ventral valve is divided as in Obolus, the pedicle scar (m) being situated between the two parts
(Pl. XVII, fig. 1f); the latter are oval in outline, their longer axis being slightly inclined forward
and outward. In the dorsal valve the umbonal scar (g) is very close to the area and extends
across nearly the entire distance between the central portion of the area delimited by the flexure
Imes (Pl. XVII, figs. 1h and 1j). In one specimen fine striz cross the scar subparallel to the
median line of the shell.

The scars of the central muscles are not clearly defined in the ventral valve, owing to their
bemg crowded in with the scars of the middle and outside laterals. Their position, judging
from the location of the centrals in Obolus, is within the trapezoidal area (c) indicated on Plate
XVII, figures 1f and 1g. The central muscle scars (bh) are large and distinctly defined on a
number of casts of the interior of the dorsal valve. They are situated a little in advance of the
center of the shell, on each side of the median septum, with their longer axis inclmed outward
at an angle of nearly 45° (Pl. XVII, figs. 1h and 1j). The anterior laterals (j) are clearly defined
in both valves; their form, size, and position are shown by figures 1f and 1g for the ventral
valve, and figures 1h and 1j for the dorsal valve. The middle and outside lateral scars on the
ventral valve are situated in the trapezoidal area (c), but neither are clearly separable in any
of the specimens in the collection unless it be m that represented by figure 1c, where a small
round sear (k) occurs, corresponding in position to that of the middle lateral scars of Obolus.
On the dorsal valve the middle and outside laterals are closely united as in Obolus, and they
are apparently combined in the elongate scar (1) (Pl. XVII, figs. 1h and 1j). This scar corre-
sponds in position with the two scars in Obolus, m which genus it is usually impossible to dis-
cover the line of demarcation between them. The transmedian scars (i) are distinctly shown
on the dorsal valve (Pl. XVII, figs. 1h and 1j), but im the ventral valve they are so closely
united with the anterior laterals (j) that it is impossible to differentiate them.

Portions of the markings left on the shell by the vascular system are finely preserved in a
few casts of the interior of the valves. The description is of the present appearance of the
casts, which is the reverse of the actual condition in the interior of the shell. The main or trunk

476 CAMBRIAN BRACHIOPODA.

sinuses (vs) are indicated for the ventral valve in figure 1g, and for the dorsal valve by figures
th and1j. The latter are rather indistinct, rounded ridges, with a few lateral branches showing
in the specimens. In figure 1g the interior lateral branches (vs) are shown, and the peripheral
sinuses (pvs) are seen in figures 1h and 1j, Plate XVII.

The parietal scar (ps) is distinctly shown in front of the visceral area of the ventral valve
(Pl. XVII, fig. 1f), but it has not been traced outside of the main sinus. In one specimen of
the dorsal valve its course may be followed from the median line in front of the anterior lateral
muscle scars, curving outward to the main vascular sinus and outside of the sinus around the
outside lateral, where it turns back toward the flexure line of the area (fig. 1)).

Observations —The specimens described by Roemer [1849, p. 420] came from a limestone
in San Saba County, Texas. He figures [1852, Pl. XI, fig. 10] a ventral valve that is larger
and more acuminate than the majority of the specimens im the collection before me; but, in
the absence of a closely allied species from the Cambrian of Texas, and im view of the fact that
there is a considerable range of variation in the form of the valves, I do not hesitate to identify
the form here described as belonging to the species studied by Roemer. He compares it [1852,
p- 90] with “‘Lingula cuneata” of the Medina sandstone of New York, to point out that it is more
acuminate than that species. It also differs from it in the character of the interior markings
and muscle scars and the greater thickness of the shell. From other species of the genus,
Lingulella acutangula varies in form and in the arrangement of the muscle scars. It is some-
what closely related to Lingulella cuneola (Whitfield) of the Middle Cambrian of the Black Hills,
South Dakota, and the latter species may even be identical with it.

FoRMATION AND LOCALITY.—Upper Cambrian: (14b) Limestone on Cold Creek at north end of gorge opposite the
north end of Sponge Mountain, 2 miles (3.2 km.) south of the San Saba County line, in Llano County; (14i) upper
part of the limestone exposed 1 mile (1.6 km.) west of Cherokee, San Saba County; (858) limestones [see Roemer,
1849, p. 420| on San Saba River, San Saba County; (68 and 68e) interbedded limestone and sandstone, Packsaddle
Mountain, Llano County; (69) limestone, near Honey Creek, Burnet County; (67 and 67c) sandstone on Tatur Hill,
7 miles (11.2 km.) northwest of Burnet, Burnet County; (358c) heavy dark ferruginous sandstone collected somewhere
- in Llano County; and (70 and 70e) limestone, near Morgans Creek, Burnet County; all in Texas.

Middle Cambrian: (11j) Basal part of Bonneterre limestone, Mine Lamotte, Madison County; and (11k) limestones
of the “ Edgewise beds,’’ beneath the Elvins formation, St. Francois County; both in Missouri.

(17c) Sandy limestone, 235 feet (71.6 m.) above the “Tonto”’ sandstone, Grand View trail, north of Last Chance
copper mine, south side of the Grand Canyon of the Colorado, Arizona.

Specimens that are somewhat doubtfully referred to Lingulella acutangula occur at the

following localities:

Upper Cambrian: (327) Arenaceous limestone east of Gold Camp, in the Caballos Mountains, Sierra County,
New Mexico.

(111) Arenaceous limestone of the Elvins formation, 50 feet (15.2 m.) above the “ Edgewise beds,’’ St. Francois
County, Missouri.

Middle? Cambrian: (318c) Limestone 12 miles (19.3 km.) west-southwest of Alpha Station, Eureka County,
Nevada.

LINGULELLA AGNOsTORUM (Wallerius).
Plate XXX, figure 15.

Lingula agnostorum WaLLERtius, 1895, Undersékningar 6fver Zonen med Agnostus lxvigatus 1 Vestergdtland, pp. 64-65,
figs. 8a-b. (Described in Latin, and discussed in Swedish, as a new species.)

Shell very small. Outline ovate, with the ventral valve subacuminate; moderately convex.
Surface of shell marked by concentric striz and strong growth lines that, near the umbo, form
deep undulations separating the minute, elevated, smaller umbo from the less elevated con-
centric ridges in front of it. The ventral valve illustrated by Wallerius is about 3 mm. in length
and that of the specimen before me is 1.5 mm. I have not seen a dorsal valve.

Observations.—This minute shell is associated with Acrotreta parvula (Wallerius) and
Agnostus levigatus. It diflers from Lingulella sp. undt. a of the Olenus truncatus zone in its
minute size, more acute beak, and less distinctly striate surface characters.

OBOLIDA. - 477

This form owes its specific name to its association with Agnostus.

FORMATION AND LOCALITY.—(310i) Limestone in passage beds between the Middle Cambrian Paradomides forch-
hammeri zone and the Upper Cambrian Olenus truncatus zone; at Borgholm, on Oeland Island, Sweden.

LINGULELLA AMPLA (Owen).
l

Plate XXVIII, figures 1, la-j.

Lingula ampla Own, 1852, Rept. Geol. Survey Wisconsin, Iowa, and Minnesota, p. 283) Pl. I B, figs. 5 and 12.
(Described as a new species, see p. 478 for copy. The specimen represented by fig. 5 is Soha in this mono-
oraph, Pl. XXVIII, fig. 1.)

Lingula ampla Owen, Hatt, 1863, Sixteenth Rept. New York State Cab. Nat. Hist., p. 125, Pl. VI, fig. 10. (Original
description, Owen, 1852, p. 583, copied and species discussed. )

Lingula ampla Owen, Haut, 1867, Trans. Albany Inst., vol. 5, pp. 101-102, Pl. I, fig. 10. (Discussion and figure copied
from preceding reference.)

Lingulella ampla (Owen), Scnucuert, 1897, Bull. U.S. Geol. Survey No. 87, p.257. (Merely changes generic reference.)

Obolus (Lingulella) amplus (Owen), Watcorr, 1898, Proc. U. 8. Nat. Mus., vol. 21, pp. 392 and 394, Pl. XXVIII,
figs. 3-4. (Mentioned in the text in discussion of Lingulella. The specimens represented by figs. 3 and 4 are
redrawn in this monograph, Pl. XXVIII, figs. 1f and 1h, respectively.)

General form ovate, with the ventral valve obtusely acuminate and dorsal valve broadly
ovate; valves moderately convex. Surface of shell marked by concentric strix, and lines of
growth and indistinct radiating strize; very fine radiating strie occur on the inner surface of
the outer layer of the shell, and the casts show the presence of papille that indicate that the
inner surface of the shell was punctate (Pl. XXVIII, fig. 1g). The shell is of medium thickness
and formed of a thin outer layer and several inner layers or lamellz which give a greater thick-
ness to the posterior half. The lamelle are arranged as in Lingulella acutangula (Roemer)
where they are slightly oblique to the outer layer.

One of the larger ventral valves has a length of 18 mm., with a maximum width of 12 mm.,
and an associated dorsal valve has a width of 12 mm. and a length of 15 mm.

_ As shown in the cast of the interior of the shell, the area of the ventral valve is nearly flat
near its lateral margin and rises from about the flexure lme toward the pedicle groove. The
pedicle furrow is shown by a narrow, elevated, rounded, tapering ridge which divides the area
midway. The area is marked also by rather strong flexure lines which extend from the beak
obliquely across the area at some distance from the outer margin, as shown in Plate XXVIII,
figures 1c-f. The striz of growth cross the area parallel with its base; they are very fine and
closely grouped together on the lateral slopes; none of the specimens show their presence on
the cast of the pedicle furrow. The area forms a thin shelf between the pedicle groove and
the lateral margins, the undercut extending backward far under the area. This is well shown
in several of the casts, although the cast of the undercut is ae! broken away. A portion
of it remains, however, in Plate XXVIII, figure 1c.

The area of the coral valve is well defined and is marked in one specimen by strong flexure
lines (f, fig. 1h), and fine transverse strize. As im the ventral valve, the area forms a thin shelf,
the cast of the undercut extending well under the area in several of the specimens. Its ragged
edges are shown in figure 11.

The cast of the interior of the ventral valve shows the visceral cavity (v), and there are
slight traces of a median septum (s) in the dorsal valve (Pl. XXVIII, fig. 1h). The muscle
scars are partly preserved. In the ventral valve the anterior laterals (j) are shown in one cast
(Pl. XXVIII, fig. 1c). The central, middle lateral, and outside lateral muscle scars are all
crowded together and lost in the space in front of the anterior portion of the visceral cavity.
The central (h) and anterior lateral (j) muscle scars are well defined in the dorsal valve (Pl.
XXVIII, figs. 1g and 1h).

Of the markings left on the cast by the vascular system only the main sinus (vs) is pre-
served (Pl. XXVIII, figs. 1c, 1d, and 1f for the ventral valve and fies. 1g and ih for the dorsal
valve).

Observations.—One of the specimens illustrated by Owen [1852, Pl. I B, fig. 5] is in this
monograph represented by Plate XXVIII, figure 1. It appears to be a ventral valve that

478 CAMBRIAN BRACHIOPODA.

has been broken away toward the apex. His second figure [1852, Pl. I Bs, fig. 12] is a partially
covered dorsal valve which shows the characteristic form and the concentric striz of the species.
His description [1852, p. 583] is as follows:

This species has a greater circumference and superficial area than any of the others hitherto discovered in F. 1.
Shell nearly oval, rather flat; beak blunt, and not projecting beyond the general contour of the shell, and formed
more after the manner of the beaks of Terabratule. A few faint concentric striz. Length 11/16 of an inch; width
8/16 of an inch.

This species occurs in the Lingula and Obolus grits, member c, near Mountain Island, at the Dalles of the St. Croix,
and elsewhere in Wisconsin.

James Hall did not have the type before him when he described the species. He identified
a form from the lower bed at Trempealeau, which he regarded [1863, p. 125] as the typical
form of the species. The original type came from Mountain Island, in the Mississippi just
above the mouth of Trempealeau River. It also occurs at about the same horizon 10 miles
lower down on the west shore of the river, opposite the mouth of Black River. Im general
form, this species somewhat resembles Lingulella billingsiana (Whiteaves) from Newfoundland,
but it differs from that species in the character of the surface markings and that of the interior
markings and scars, especially those of the dorsal valve. The position of the main vascular
sinus of the dorsal valve distinguishes it from other species of which we have the interior mark-
ings. In a specimen of the ventral valve (Pl. XXVIII, fig. 1f) there appears to be a unique
marking (y) in the central anterior portion of the valve. It recalls the heart-shaped pit (x)
of Obolus and Lingulella acutangula (Roemer) (Pl. XVII, fig. 1f), but it is so far away from
the normal position of that pit that it appears to be the result of a malformation or an impression
in the cast which accidentally resembles the outline of the heart-shaped pit.

FoRMATION AND LOCALITY.—Upper Cambrian: “St. Croix sandstone” at the following localities: (80) 0.66 mile
(1.1 km.) southwest of the railway depot at Menomonie, Dunn County; (100) near Menomonie, Dunn County; and
(98) near Eau Claire, Eau Claire County; all in Wisconsin.

Middle Cambrian: (84 and 84f) “St. Croix sandstone,” at Dresbach opposite the mouth of Black River, Winona.
County; (84s) near Dakota, Winona County; and (339e) on Mountain Island, Minnesota, in Mississippi River just above
the mouth of Trempealeau River; all in Minnesota.

(328g) Wisconsin shore of the Mississippi, near Trempealeau, Trempealeau County; and (828e) “St. Croix sand-
stone”’ at St. Croix Falls, Polk County; both in Wisconsin.

A closely related if not identical species occurs at the following locality. A ventral valve
from this locality is illustrated in Plate XXVIII, figure 1).

Middle Cambrian: (88a) Limestone about 100 feet (30.5 m.) above the quartzitic sandstone at the base of the:

Cambrian in the northern suburbs of Deadwood, Black Hills, South Dakota.

) /

LINGULELLA ARGUTA (Walcott).

Plate XXIV, figures 5, 5a-b.

Lingula? manticula Watts (in part), 1874, U. S. Geog. Surveys W. 100th Mer., Prelim. Rept. on Invertebrate Fossils,
pp. 9-10. (Described as a new species, including specimens referred to inet Linguletla arguta and L. manticula.):

Lingula? manticula Wxitx (in part), 1877, U.S. Geog. Surveys W. 100th Mer., vol. 4, pp. 52-53, Pl. III, fig. 2a (not
fig. 2b). (Described and discussed. The specimen represented by fig. 2a is redrawn in this aaoneermpls, 1k
XXIV, fig. 5. The specimen represented by fig. 2b is referred in this monograph to Lingulella manticula.)

Obolus (Lingulella) argutus Waucort, 1898, Proc. U.S. Nat. Mus., vol. 21, p. 396. (Described and discussed as below

as a new species.)

General form ovate, with the ventral valve obtusely acuminate; valves moderately con—

vex. Exterior surface of the shell unknown. Very fine radiating strize and concentric lines
of growth occur on the outer surface of the inner layer of the shell. The shell appears to be

of medium thickness and formed of a thin outer layer and one or more thin inner layers or

lamellae. The type specimen of the ventral valve has a length of 6 mm. and a width of 4.5 mm.

Observations.—This species is founded upon one of the specimens illustrated by White:

[1875, Pl. III, fig. 2a] as Lingula? manticula. The broadly ovate form of the ventral valve
clearly distinguishes it from that species. From the associated fragments of trilobites it evi-
dently occurs at a lower horizon in the Middle Cambrian. A dorsal valve from the same locality

—

Ly

OBOLIDA A479

and in a slightly different character of limestone is illustrated and provisionally referred to the
same species (Pl. XXIV, fig. 5a).

In outline this shell resembles Lingulella bella (Walcott) and L. bellula (Walcott) from
Newfoundland; it is more broadly acuminate than these species and much smaller than
Lingulella bella. It may also be compared with L. punctata (Walcott), from which it differs in
being more ovate.

FoRMATION AND LOCALITY.—Upper Cambrian: (313f) Limestone at Schellbourne, Schell Creek Range, White Pine
County, Nevada.

Middle Cambrian: (8e) Thin-bedded limestone less than 400 feet (121.9 m.) above the quartzitic sandstones of
the Cambrian, near Ophir, Oquirrh Range, Tooele County, Utah.

(11w) About 1,050 feet (320 m.) above the Lower Cambrian and 3,350 feet (1,021.1 m.) below the Upper Cambrian
in the shales forming 1d of the Swasey formation [Walcott, 1908f, p. 182], at the head of Dome Canyon; (3w) about
2,350 feet (716.3 m.) above the Lower Cambrian, and 2,050 feet (624.8 m.) below the Upper Cambrian, in the central
portion of the thin-bedded limestones forming le of the Marjum limestone [Walcott, 1908f, p. 180], in the cliff about
2 miles (3.2 km.) southeast of Marjum Pass; (10y) about 2,900 feet (884 m.) above the Lower Cambrian and 1,500 feet
(457.2 m.) below the Upper Cambrian in the central portion of the limestone forming la of the Marjum limestone
[Walcott, 1908f, p. 179], about 1 mile (1.6 km.) south-southwest of Marjum Pass; (8x and 11x) about 2,200 feet (670.6 m.)
above the Lower Cambrian and 2,200 feet (670.6 m.) below the Upper Cambrian, in the limestones forming 1d of the
Marjum limestone [Walcott, 1908f, p. 180], 2.5 miles (4 km.) east of Antelope Springs, in ridge east of Wheeler Amphi-
theater; and (11g and 11y) about 2,350 feet (716.3 m.) above the Lower Cambrian and 2,050 feet (624.8 m.) below the
Upper Cambrian, in the limestones forming 1c of the Marjum limestone [Walcott, 1908f, p. 180], 2.5 miles (4 km.) east
of Antelope Springs, in ridge east of Wheeler Amphitheater; all in the House Range [Walcott, 1908f, Pls. XIII and
XV], Millard County, Utah.

(14m) Limestone about 7 miles (11.2 km.) south of Towner’s ranch, Indian Creek, Lincoln County; (54) Eldo-
rado limestone [Walcott, 1908f, p. 184], on the east slope of Prospect Mountain, in New York Canyon, Eureka district
[Hague, 1892, Atlas], Eureka County; (59) limestone at the base of the western slope of Combs Peak, near the plain
of Antelope Valley, Kureka district [Hague, 1892, Atlas], Hureka County; and (318e) limestone 2 miles (3.2 km.)
west of Green’s ranch, White Pine County; all in Nevada.

A shell which is provisionally referred to Lingulella arguta occurs associated with the latter
species in the following locality:

Middle Cambrian: (318a) Limestone at Schellbourne, Schell Creek Range, White Pine County, Nevada.

LINGULELLA ATAVA (Matthew).
Plate XX XV, figures 5, 5a-h.

Leptobolus atavus MATTHEW, 1899, Bull. Nat. Hist. Soc. New Brunswick, vol. 4, pt. 3, No. 18, pp. 200-201, Pl. II,
figs. la-b and d-f. (Described and discussed as a new species. The specimens represented by figs. la and 1d
are redrawn in this monograph, Pl. XX XV, figs. 5 and 5c, respectively.)

Obolus (Lingulepis) gregwa Waucotr (in part) [not (MatrHEw)], 1901, Proc. U. S. Nat. Mus., vol. 23, pp. 692 and 694.
(Matthew’s ‘‘Leptobolus atavus” mentioned as the young of “‘Lingulepis gregwa.’’)

Obolus (Lingulella) atavus (Matthew), Watcorr, 1902, Proc. U. 8. Nat. Mus., vol. 25, pp. 609-610. (Described and
discussed essentially as below.)

Leptobolus atavus MatraEw, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, pp. 106-109, Pl. V1,
figs. 2a-b and d-g. (Described and discussed. Figs. 2a-b, d-e, and g are copied from Matthew, 1899b, Pl. II,
figs. la-b and d-f, respectively.)

General form elliptical, with the ventral valve subacuminate, and the dorsal valve broadly
subacuminate in outline. In the shorter form of the valves the sides are almost uniformly
rounded from the cardinal slopes to the frontal margin. The convexity of the valves is fairly
strong, that of the dorsal valve being broken by a slight longitudinal flattening that extends
from the posterior portion to the frontal margin. As shown by the matrix, the outer surface
is marked by concentric ridges and fine striz of growth. The interior cast shows concentric
lines and traces of rather coarse radiating les. None of the specimens preserve the shell,
but from the strength of the interior surface markings it is inferred that the shell was rather
thick.

The longest ventral valve in the collection has a length of 6 mm.; width, 3.5 mm. The
dorsal valves are slightly shorter.

The area of the ventral valve is divided at the center by a strong pedicle furrow, and
about midway between the pedicle furrow and the outer margin by clearly marked flexure

480 CAMBRIAN BRACHIOPODA.

lines that extend from the apex, with a slightly outward curvature, to the base of the area.
Striz of growth cross the area parallel with its base, bemg much stronger on the area than in
the pedicle furrow. The area of the dorsal valve is fully as prominent as that of the ventral
valve. It curves forward at the center and extends well out on the cardinal slopes. The
flexure lines are clearly defined well out toward the lateral margin. The striz of growth cross
the area parallel to the base.

The cast of the interior of the ventral valve shows only the outline of the visceral cavity,
and that the main vascular sinuses extend a considerable distance in advance of the visceral
cavity. The cast of the interior of the dorsal valve shows that it had a strong, broad, central
ridge, divided by a faint longitudinal median sinus. Only traces have been seen of the main
vascular sinuses.

Observations.—This is a very pretty little species that, in the absence of well-defined speci-
mens, I [1901, p. 694] confused with the young of “‘Lingulepis gregwa’”’ Matthew. Material
collected by 5. Ward Loper at the type locality, however, proves that the shell differs consider-
ably from that of the young of Lingulella (Lingulepis) gregwa, although specimens of the dorsal
valve of the two furms are often very much alike.

Matthew’s illustrations [1903, Pl. VI, figs. 2a—b, d-g] of Lingulella atava are somewhat
diagrammatic, as though they were drawn to represent the average form of several specimens.
With the type specimens before me I find considerable variation in width and outline. Some
have the outline of Lingulella collicia (Matthew) and the two types of the latter species are
much like Matthew’s figures of Lingulella atava [1903, Pl. VI, figs. 2a-b, d-g]. The specimens
of Lingulella collicia have the rotund, subquadrate outline of Lingulella atava and not the uniform
curvature of Matthew’s figures of Lingulella collicia (1903, Pl. VI, figs. 3a, 3b]. With a large
series of well-preserved material from the type locality and formation, I have endeavored to
represent two forms that may be referred to Lingulella atava and Lingulella collicia, respectively.
Lingulella atava is more slender and its sides are more uniformly curved than L. collicia, and it
is also usually larger. Lingulella cania (Walcott) is a narrow, elongate form.

FoRMATION AND LOCALITY.—Middle Cambrian: (10p) Sandstones just below the waterfall in Division E2b; (18d
and 13d’) sandstones opposite the third waterfall, between Divisions E2a and EH2b; (181’) sandstones of Division
E8a; (844) sandy shales of Division E3b; (18n’” and 344b) sandstones of Division H3d; (18n’) sandstones of Division
He; and (138n and 344d) sandstones of Division H3f; all in Matthew’s [1903, p. 21] Etcheminian, on Dugald Brook,
Indian River, eastern Cape Breton, Nova Scotia, Canada.

LINGULELLA ATAVA INSULa (Matthew).
Plate XX XV, figures 8, 8a.

Leptobolus atavus insule MattHew, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, pp. 110-112,
Pl. VI, figs. 4a-c. (Described and discussed as a new variety. The specimens represented by figs. 4a and 4b
are redrawn in this monograph, Pl. XX XV, figs. 8 and 8a, respectively.)

The form of this shell is much like that of Lingulella cania (Walcott) or a narrow L. atava
(Matthew). The material representing it is not well preserved. Matthew [1903, Pl. VI, figs.
4a—c] has illustrated it with three somewhat diagrammatic figures that give his conception of
its form and interior markings. I have figured two of the best preserved of the typical
specimens. They show the general form and character to be similar to those of L. atava.

FoRMATION AND LOCALITY.—Middle Cambrian: (307d [Matthew, 1903, p. 110]) Sandstones believed to belong to
Division E2a of Matthew’s Etcheminian, at Youngs (McFees) Point, George River, eastern Cape Breton, Nova Scotia.

LINGULELLA AUGA (Walcott).
‘ Plate XXIV, figures 6, 6a-¢.

Obolus (Lingulella) auga Waucort, 1898, Proc. U. S. Nat. Mus., vol. 21, pp. 396-397. (Described as below as a new
species.) se
General form subcuneate, with ventral valve obtusely acuminate, and the dorsal valve
rounded acuminate; valves moderately convex. Surface of the shell, as mdicated by casts

218n’ is the type locality, though the specimens in the United States National Museum collections to which that number is assigned were
collected later than the type specimens. Localities 344, 344b, and 344d are cited by Matthew (see pp. 268-269).

OBOLIDA. 481

in the fine sandstone, marked by lines of growth, and fine, slightly undulating strie; the inner
surface is marked by somewhat irregularly scattered pits or punctx, some of which are unusually
large for the size of the shell. The few remaining traces of the shell indicate that it was relatively
thin. The largest well-preserved cast of the ventral valve has a length of 5 mm., with a width
of 4.5 mm. The dorsal valves are a little shorter, the length and breadth being nearly the
same. Casts of the interior of the ventral valve show the presence of a rather long area divided
midway by a narrow, clearly defined cast of a pedicle groove; traces of flexure lines are also
preserved. The area of the dorsal valve is proportionately shorter than that of the ventral
valve; traces of the visceral cavity (v) and the base of the main vascular sinuses (vs) are pre-
served in a few specimens and in one specimen the anterior lateral muscle scars appear to be
present.

Observations—In the form of the valves this species is somewhat similar to Lingulella
grandis (Matthew) (Pl. XXX VIII); otherwise it appears to be quite distinct from any other
described species. It has a long cardinal area and a narrow, deep pedicle furrow on the ventral
valve.

FoRMATION AND LOCALITY.—Middle Cambrian: (10a) Sandstones of the Rome formation, in west railroad cut
through Shooks Gap; and (10b) limestones of the Rome formation at the western end of the central railroad cut through

Shooks Gap; both in Bays Mountains, 10 miles (16.1 km.) southeast of Knoxville [Keith, 1895, areal geology sheet],
Knox County, Tennessee.

is LINGULELLA BELLA (Walcott).
Plate XIX, figures 2, 2a-q; Plate XXXVI, figure 4.

Obolus (Lingulelia) bellus Waxcort, 1898, Proc. U. 8. Nat. Mus., vol. 21, pp. 397-398. (Described and discussed as a
new species.)

Obolus (Lingulella) bellus Watcorr (in part), 1901, Proc. U. 8. Nat. Mus., vol. 23, pp. 685-687. (Described and dis-
cussed, including specimens now referred to Lingulella concinna Matthew and L. lens (Matthew).)

Obolus (Lingulella) bellus Walcott, MatrHmw, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, p. 204.

(Says “‘O. (L.) bellus” does not include “‘Lingulella concinna” .)

General form ovate, with ventral valve obtusely acuminate, and dorsal valve broad ovate
to ovate quadrate; valves moderately convex as far as can be determined from the somewhat
compressed specimens as they occur in the sandy shales. The small ventral valves are more
acuminate than the large ones and the smaller dorsal valves are more elongate. The change
in form is slight from one to another specimen in the series, but the two extremes are so different
that without the connecting series two species could be determined.

Surface of shell with numerous concentric lines of growth and fine radiating lines. The
inner layers are marked by concentric lines and numerous fine radiating striz.

The shell is relatively thin over the anterior portions and stronger near the cardinal mar-
gins. It is formed of a very thin outer layer, with-one or more thin layers or lamelle. The
casts of the interior surface of the ventral valve show numerous papille arranged in concentric
lines on the posterior half of the shell. These correspond to the puncte of the inner surface.

A large ventral valve has a length of 22 mm.; width, 15 mm.; and a dorsal valve 18 mm.
in length had a width of 14 mm. The specimens in the collection average from 2 to 3 mm.
smaller than those measured.

The cast of the area of the ventral valve shows that it was rather long and extended well
out onto the cardinal slope; it is divided midway by a strong pedicle furrow, and toward the
lateral margin by a narrow flexure line. The area is marked by fine strie of growth parallel
to the margin. The area of the dorsal valve is rather short, but it extends laterally well out
on the cardinal slopes. The shallow curve corresponding to the pedicle groove of the larger
valve is wide and clearly defined.

The casts of the interior of the valves show almost no traces of the vascular markings or
muscle scars. Only the central and anterior lateral muscle scars and the main vascular sinuses
have been observed in the ventral valve.

62667°—vot 51, pr 1—12——31

‘482 CAMBRIAN BRACHIOPODA.

Observations.—This fine species occurs in great abundance in the upper beds of Little Belle
Island associated with a narrow form of Lingula; and also im the higher beds on Great Belle
Island, and a little below the layers carrying Obolus (Lingulobolus) affinis (Billings) and O. (L.)
spissus (Billings). The species is found at some little distance above the horizon in which I
collected a species of Olenus and I refer the horizon to the Ordovician or the passage beds to
the Ordovician fauna.

The species appears to be clearly distinct from any described form. It may be compared
with Lingulella davisi (McCoy) in relation to its size and outline, but not in other respects.
It differs in the size and position of the muscle scars and the more strongly punctate interior
surface. Some of the smaller shells closely resemble Lingulella concinna Matthew and the
larger ones L. lens (Matthew). When studying the material of the two latter forms in 1901,
I referred them all to Lingulella bella [Walcott, 1901, p. 685], but with the large series now
before me this reference is not sustained.

ForRMATION AND LOCALITY.—Lower Ordovician: (114b) Sandstone 1 mile (1.6 km.) north of Lance Cove, Great Belle
Island, Conception Bay, Newfoundland.
Upper Cambrian: (114 and 114a) Uppermost sandstone beds and the sandy shales underlying them on Little Belle

Island, in Conception Bay, Newfoundland.
(343b) Limestone pebble on Sachuset Beach, near Newport, Narragansett Bay, Rhode Island.

LINGULELLA BELLULA (Walcott).

L Plate XIX, figures 1, la-e.

Obolus (Lingulella) bellulus Waxcort, 1898, IFSOE: U.S. Nat. Mus., vol. 21, p. 398. (Described and discussed as below,
as a new species.)
Obolus (Lingulella) bellulus Walcott, MartHEw, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton,

p. 205. (Says this species and “‘Lingula billingsana” Whiteaves are the same.)

General form ovate with the ventral valve obtusely acuminate; dorsal valve round ovate;
valves moderately convex. Surface of shell marked by concentric lines of growth and exceed-
ingly fine, irregular striz that give the same appearance to the surface as that seen on.Obolus
(Westonia) ella (Hall and Whitfield), Obolus fragilis (Walcott), and on a larger scale on
Lingulella radula Matthew. The outer layer of the shell usually adheres to the arenaceous
matrix, leaving the shiny inner layer on the shell; this is marked by concentric striz and lines
of growth, and fine radiating strie. The shell is thin and formed of a very thin outer layer
and one or more thin inner layers or lamelle.

The average length of the ventral valve is from 4 to 5 mm.; width, 3 to 3.5 mm. The
dorsal valves are a little shorter, 0.5 mm. to 1 mm.

The cast of the area of the ventral valve shows it to be elongate, divided midway by a
narrow but strong pedicle furrow, and, about midway between the pedicle furrow and the
lateral margin, na a narrow flexure itr: it is marked by striz of growth parallel to its base.
The area on the dorsal valve is not well shown on the specimens in the collection.

The cast of the interior of the ventral valve shows somewhat imperfectly the visceral cavity,
but not the muscle scars. In an interior of the dorsal valve the main vascular sinuses (vs)
are well shown (Pl. XIX, fig. 1d), also the median septum (s). The central muscle scars are
faintly shown in one fragmentary interior of the dorsal valve.

Observations.—This beautiful little species occurs in the arenaceous shales and thin-bedded
sandstones of Little Belle Island, in association with the larger species Lingulella bella (Walcott).
It is closely related to Lingulella ferruginea Salter, but differs somewhat in form and the more
anterior position of ‘‘the visceral cavity in the dorsal valve.” The species is the Upper Cam-
brian representative of the Middle Cambrian species L. ferruginea. It occurs at about the
same horizon as L. billingsiana (Whiteaves), but differs decidedly from it in form and convexity,
the only points of comparison which the material permits.

ForMATION AND LOCALITY.—Upper Cambrian: (114 and 114a)¢ Uppermost sandstone beds and the sandy shales
underlying them on Little Belle Island, Conception Bay, Newfoundland.

@114a is the type locality.

OBOLIDA. 483

LINGULELLA BILLINGSIANA (Whiteaves).

Plate XXIX, figures 3, 3a.

Lingula billingsiana WurteaveEs, 1878, Am. Jour. Sci., 3d ser., vol. 16, p. 226. (Described, see below, as a new species.)

Lingulella? billingsana (Whiteaves), ScnucnER? (in part), 1897, Bull. U.S. Geol. Survey No. 87, p. 256. (Merely
changes generic reference and spelling of Whiteaves’s Lingula billingsiana, cited above. Includes also reference
to specimens now referred to Lingulella grandis.)

Not Lingula billingsana Whiteaves, MatruEw, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, p. 205.
(Mentions ‘‘Obolus (Lingulella) bellulus” Walcott as the same as ““Lingula billingsana.’’)

The original description by Whiteaves follows:

Shell small, very slightly convex, compressed at the sides; outline elliptic ovate, narrowest behind; length nearly
twice the width; margin of the valves widening convexly and gradually from the beaks to the center, or a little
beyond it; front narrowly and evenly rounded. Surface marked by fine concentric striations and faint radiating
lines. Internal markings unknown. Length, about two lines and a half; width, one line and a half.

Observations.—Through the courtesy of Prof. J. F. Whiteaves I have been able to study
the type specimens of this species. Much to my surprise I find them to be distinct from the
forms (Lingulella bella and L. bellula, Pl. XIX) I collected on Little Belle Island and Great Belle
Island, Conception Bay, and those (Lingulella grandis (Matthew), Pl. XX XVIII) tentatively
compared with the species by Matthew. The shell is more elongate and convex than that of
Tingulella bella (Walcott). Two specimens of the ventral valve are illustrated (Pl. XXIX,
figs. 3 and 3a). No dorsal valves occur in the material available for study.

The outer surface is exfoliated from all of the specimens so as to show the shiny surface
of the inner layer described by Whiteaves [1878, p. 226]. One of the broken ventral valves
shows a narrow pedicle groove.

The specific name was given in honor of Mr. E. Billings.

ForMATION AND LOCALITY.—Upper Cambrian: (314a | Whiteaves, 1878, p. 226]) Shales on Kelleys Island, Concep-
tion Bay, Newfoundland.

LINGULELLA BORNEMANNI (Walcott).

Plate XXX, figures 18, 18a—c.

-

Tingula attenuata BoRNEMANN [not SowErRBy], 1891, Nova Acta Acad. Czes. Leop.-Carol. Germanicz Nature Curio-
sorum, Bd. 56, No. 3, pp. 437-438, Pl. XIX (XXXIV), figs. 1-10. (Described and discussed in German, see
below for liberal translation. Figs. 10a, 4, 8, and 7 are reproduced in this monograph, Pl. XXX, figs. 18,
18a-c, respectively.)

Obolus (Lingulella) bornemanni Waucorr, 1901, Proc. U. S. Nat. Mus., vol. 22, pp. 687-688. (Described and dis-
cussed essentially as below as a new species.)

The original description by Bornemann follows:

Shell oblong oval, sharply pointed toward the beak, marked with fine concentric stripes which are usually recular,
and also often marked with large, irregular, concentric folds. Faint radia) or longitudinal striation usually appears
distinctly on the surface in the center of the shell. At the vertex there is usually a distinct, straight, longitudinal
impression.

Shape exceedingly variable, often unsymmetric, short rounded-triangular or almost circular, or narrower and
elongated, more or less arched or even flat. The long-extended specimens resemble Lingulella (Lingulépis) acwminata
(Conrad); others agree perfectly with Murchison’s original figures of Lingula attenuata; others again may be compared.
with Lingulella davisi (McCoy) and were at first placed with that species. The simultaneous occurrence in enormous
multitudes and the numerous transition stages leave no doubt that all these forms belong to one species, and the average
type of them fits best to Lingula attenuata Sowerby.

Size, 2 to9 mm.

The state of preservation is best in the slates, yet there the specimens are mostly pressed flat. The specimens
existing in great numbers in the sandstones often still exhibit their original arching, but the delicate shells are
ordinarily distorted in an irregular manner and poorly preserved.

Bornemann [1891, p. 437] identified this species with Lingula attenuata Sowerby, on account
of the resemblance in outline of many of the specimens. Other specimens closely resemble Lin-
gulella (Lingulepis) acuminata (Conrad) from the Middle and Upper Cambrian of North America.
It is so improbable that a species of this character should persist from Middle Cambrian time
to Middle Ordovician time that, notwithstanding the resemblance, I think it is better to

484 CAMBRIAN BRACHIOPODA.

distinguish it from Lingula attenuata Sowerby [Davidson, 1866, p. 44] and give a specific name
that will not lead to erroneous stratigraphic correlations. The Cambrian fauna of Sardinia is
so distinct from that of other localities and the stratigraphic succession of the subfauna is so
confused that I think it unwise to identify its species with described species unless the material
is so full and well preserved that there is no doubt of their specific identity.
The specific name was given in honor of Dr. J. G. Bornemann.
ForMATION AND LOCALITY.—Middle? Cambrian: (354) Yellowish-brown slates not far from the buildings of Canal

Grande; (354a) grayish-white quartzitic sandstone in the valley of Gutturu Sartu; (354b) yellowish sandstone with
Archxocyathus at Punta Pintau and elsewhere; all [Bornemann, 1891, p. 438] in the island of Sardinia, Italy.

LINGULELLA BUTTSI Walcott.
Plate X XIX, figures 4, 4a—b. -

Lingulella buttsi Watcort, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, pp. 70-71, Pl. VIII, fig. 6. (Described and

discussed as below as a new species. Fig. 6 is copied in this monograph, Pl. X XIX, fig. 4.)

General form elongate ovate, with the ventral valve bluntly acuminate and the dorsal valve
a little more rounded on the posterior margin. Both valves rather strongly convex. ‘The great-
est convexity of the dorsal valve is at the umbo, and of the ventral valve along the central sec-
tion. A ventral valve 12 mm. in length has a convexity of 2 mm., and a dorsal valve 8 mm.
long arches 1.75 mm. above the plane of the margin. A narrow, median, slightly flattened,
almost concave space that extends from the apex to the front margin occurs on the dorsal
valve. The exterior surface of the shell is dull dark-bluish gray and the inner layers shiny
bluish black. The outer surface is marked by concentric striz and lines of growth with a few
indistinct radiating striz; the striz on the dorsal valve bend slightly backward where they cross

the median, flattened space. The imner layers have many concentric strie, also numerous ~

fine radiating strie. The shell is built up of several layers or lamellz, so as to be strong in the
umbonal region and thin toward the edges.

The largest ventral valve in the collection has a length of 12 mm. and a maximum width
of 9.5 mm. at the anterior third of its length; a dorsal valve 10 mm. long has a width of 7 mm.

A partly exfoliated ventral valve indicates the presence of a strong ridge on each side of
the visceral area somewhat similar to that in Lingulella acutangula (Roemer) (Pl. XVII).

Observations.—This fine shell has the general outline of the group of small shells of which
Lingulella ferruginea Salter is typical. It differs from them in its large size and strong shell.
All of the larger species of Lingulella are either more acuminate or broader in outline.

The material was collected by Mr. Charles Butts, of the United States Geological Survey,
and I take pleasure in naming the species after him.

ForMATION AND LOCALITY.—Middle Cambrian: (90b) Conasauga limestone in cut on Louisville and Nashville
Railroad, near Woodstock; and (90c) Conasauga limestone near Kimbrel; both in Bibb County, Alabama.

LINGULELLA CANIA (Walcott).

Plate XX XV, figures 3, 3a-d.
Obolus (Lingulepis) gregwa Waucort (in part) [not (MatrHEw)], 1901, Proc. U.S. Nat. Mus., vol. 23, p. 694. (Speci-

mens now referred to Lingulella cania are here mentioned as representing the young of Lingulella (Lingulepis) .

Tegwa. -
Ae i aaieits canius Waucorr, 1902, Proc. U. 8. Nat. Mus., vol. 25, pp. 610-611. (Described as below as a new
species. )

Shell small. General form elongate oval, with the ventral valve slightly acuminate. In
both the ventral and dorsal valve the shell narrows posteriorly, the front being broadly rounded.
The convexity of the two valves is well marked, and it is nearly the same in each.

Surface of the shell marked by fine concentric strize and a few lines of growth. When the
outer shell is exfoliated fine radiating striz cross the fine concentric striz. The shell appears
to be of moderate thickness and formed of several thin layers or lamelle. The largest ventral
valve in the collection has a length of 5 mm.; width, 3 mm.; and a dorsal valve 4 mm. in length
has a width of 2 mm.

OBOLIDA. 485

The area of the ventral valve is elongate, being nearly one-fifth the length of the shell. It
is divided midway by a very distinctly defined pedicle furrow. The flexure line is just percep-
tible about half the distance out from the pedicle furrow to the lateral margin.

The area extends well forward on the cardinal slopes and is marked by strong striz of
growth parallel to its base. The area of the dorsal valve is shorter than that of the ventral,
and is marked by fine lines of growth and clearly marked flexure lines that extend from the
apex forward on a line with the maim vascular sinuses.

The cast of the interior of the ventral valves shows a general outline of the visceral cavity
and the main vascular sinuses. Only the base of the main vascular sinus has been seen in the
dorsal valve.

Observations.—This very pretty little species occurs in association with Paradoxides. In
my first study of the brachiopods collected by 5. Ward Loper from Cape Breton I confused it
[1901, p. 694] with the young of Lingulella (ingulepis) greqwa (Matthew). By means of a larger
collection made by Loper in 1901, I have been able to separate it from the young of the associ-
ated Lingulella (Lingulepis) exrgua (Matthew) and from somewhat similar species that occur at
a lower horizon, Lingulella atava (Matthew) and L. collicia (Matthew). It differs from both the
latter species in having a more elongate oval outline. It differs from the young of Lingulella
(Lingulepis) gregwa in being more regularly oval and in having the posterolateral margin
curved instead of nearly straight.

FORMATION AND LOCALITY.—Middle Cambrian: (31) Compact, fine-grained, thin-bedded, gray sandstone of the

Paradoxides zone, on McLeans Brook, 1 mile (1.6 km.) east of McCodrum Brook and 1.5 miles (2.4 km.) west of Marion
Bridge; and (10s) sandstone on McLeans Brook, near Marion Bridge; both in eastern Cape Breton, Nova Scotia, Canada.

LINGULELLA CEDENS (Barrande)
Plate XXX, figure 8.
Lnngula cedens BARRANDE, 1868, Faune silurienne des environs de Hof, en Baviére, p. 102, fig. 66. (Described in

French. Fig. 66 is copied in this monograph, Pl. XXX, fig. 8.)

Lingula cedens BARRANDE, 1868, Neues Jahrb. fiir Mineralogie for 1868, pp. 691-692, unnumbered plate, fig. 66. (Copy
of preceding reference.)

This is one of the larger shells of the fauna at Hof, but as it is deformed by pressure it is
difficult to give its specific characters. The author states that the surface of the internal cast
contains traces of rather strong concentric striw, with finer intermediate striz; also traces of
very fine longitudinal strie. Length, 18 mm.; greatest width, 12 mm.

Barrande [1868a, p. 102] compares this form with Lingulella davisi (McCoy), from which it
appears to be very little different. It is probable that an extended series of specimens would
unite it with Lingulella wirthi (Barrande).

ForRMATION AND LOCALITY.—Passage beds between the Upper Cambrian and the Ordovician: (303¢ [Barrande,

1868a, p. 102]) Suburbs of Hof; and (308f [Pompeckj, 1896a, pp. 7 and 8]) railway cut near Schellenberg, a little dis-
tance back of the railway station at Neuhof, near Hof; both in Bavaria, Germany.

LINGULELLA CLARKEI N. sp.
Text figures 42A—D, page 486.

The ventral valve of this species has the same general outline and form as that of Lingulella
acutangula (Roemer) (Pl. XVII, figs. 1, 1a, 1g) except that it is a little broader across the front.
The dorsal valve differs materially in being proportionally narrower on the posterior half and
in having a broad shallow sinus extending from the umbo to the front margin. A similar sinus
occurs on one dorsal valve of Linqulella manticula (White) (Pl. XX, fig. 1a) and on all dorsal
valves of Obolus (Fordima) perfectus Walcott (Pl. LXIII, fig. 10b).

The largest ventral valve has a length of 9 mm.; width, 7mm. A broad dorsal valve has
a length of 5 mm.; width, 4.25 mm.

486 CAMBRIAN BRACHIOPODA.

The exterior surface is marked by very fine concentric strize or fine ridges of growth;
numerous radiating striz occur on the inner layers of the shell. Nothing is known of the interior
of either valve.

The specific name is given in honor of Prof. J. M. Clarke, of Albany, New York.

FIGURE 42.—Lingulella clarkei n. sp. A, A’, Exterior and side outline of ventral valve (U.S. Nat. Mus. Cat. No. 518532). 3B, Exterior of ventral
valve, the type specimen (U.S. Nat. Mus. Cat. No. 51853b). C, Broad form of dorsal valve (U.S. Nat. Mus. Cat. No. 51853¢). D, Dorsal valve
with exterior layer of shell exfoliated (U. S. Nat. Mus. Cat. No. 52458a). .

The specimens represented by figures 42A, 42B, and 42C are from Locality 58; that represented by figure 42D is from Locality 60; both in Nevada.

FoRMATION AND LOCALITY.—Middle Cambrian: (60) Limestone in the upper beds of the Secret Canyon shale,
across the canyon from the dump of the old Richmond mine shaft; and (58) shaly limestones in the upper part of the ~
Secret Canyon shale, east side of New York and Secret canyons; both in the Eureka district [Hague, 1892, Atlas], Eureka
County, Nevada.

LINGULELLA COLLICIA (Matthew).

a Plate XXXV, figures 1, la-f, 2, 2a-d.

Leptobolus ? collicia MartHEw, 1899, Bull. Nat. Hist. Soc. New Brunswick, vol. 4, pt. 3, No. 18, p. 200, Pl. I, figs. 3a-e.

: (Described as a new species. Figs. 1, lab, Pl. XX XV, of this monograph are drawn from three of Matthew’s
specimens, but closer identification is impossible.)

Obolus (Lingulella) collicia (Matthew), Watcorr, 1902, Proc. U. S. Nat. Mus., vol. 25, p. 610. (Characterized.)

Leptobolus collicia MartHew, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, pp. 112-118, Pl. VI,
figs. 3a-e.. (Described and discussed. Figures copied from Matthew, 1899b, Pl. I, figs. 3a-e.)

Leptobolus collicia collis MattaEw, 1903, idem, pp. 114-115. (Characterized as a new variety.)

This shell is associated with Lingulella atava (Matthew), but differs from that species i
in being larger and in having a more acuminate and broader ventral valve and more broadly f
oval dorsal valve. The exterior surface is marked by very fine, slightly irregular, concentric
strie. The variety collis is simply a wide form, that is so closely united to L. collicia by many
eradations among the shells before me that I do not think it worthy of a distinct name. f

FoRMATION AND LOCALITY.—Middle Cambrian: (10p) Sandstones just below the waterfall in Division H2b; (1347)
sandstones opposite the third waterfall in Dugald Brook, between Divisions E2a and E2b; (344a [Matthew, 1903, ;
p. 26]) sandy shales of Division E8c; (18n’)@ sandstones of Division E3e; (344d [Matthew, 1903, p. 82]) sandy shales of
Division H3f; all in Matthew’s [1903, p. 21] Etcheminian, Dugald Brook, Indian River, Cape Breton, Nova Scotia.

(18m) Sandstones of Division E3f in Matthew’s Etcheminian, Gillis Brook, eastern Cape Breton, Nova Scotia.

(344e [Matthew, 1903, p. 78]) Shales of Division Eld of Matthew’s Etcheminian, on Boundary Brook, eastern
side of the Escasonie Indian Reservation, eastern Cape Breton, Nova Scotia, Canada.

LINGULELLA concrINNA Matthew.
Plate XX XIII, figures 2, 2a-h; Plate XXXIV, figures 1, la—.

Lingulella concinna Marrunw, 1901, Bull. Nat. Hist. Soc. New Brunswick, vol. 4, pt. 4, No. 19, pp. 273-274, PL.V,
figs. 2a-b. (Described and discussed as a new species. Pl. XXXIII, fig. 2d, of this monograph is drawn from
one of Matthew’s specimens, but which one can not be determined.)

Obolus (Lingulella) bellus Waxcorr (in part), 1901, Proc. U. S. Nat. Mus., vol. 23, p. 685. (Matthew’s Lingulella
concinna is referred to, and described with Lingulella bella.) ~

Obolus (Lingulella) concinnus (Matthew), Watcort, 1902, idem, vol. 25, pp. 608-609. (Described and discussed some-
what as on p. 487.)

6

a18n’ is the type locality, though the specimens in the United States National Museum collections to which that number is assigned were
collected later than the type specimens.

OBOLIDA. 487 .

Lingulella concinna MatrHEw, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, pp. 203-204, Pl. XIV,
figs. 5a-b. (Description and figures copied from Matthew, 1901a, p. 273, Pl. V, figs. 2a—b.)

General form ovate. Ventral valve obtusely acuminate; dorsal valve broad, rounded
ovate; valves moderately convex. Surface of shell marked with numerous concentric lines of
growth and with intervening bands of striz that are somewhat undulating. When the outer
surface of the shell is exfoliated the shiny inner layers of the shell are marked by both con-
centric and radiating strie. :

The shell is thin and formed of a thin outer layer, and several thin inner layers or lamelle.
In some of the layers of argillaceous shale the shell has a bluish tinge with a glistening surface,
often wrinkled and ridged by longitudinal compression and also compressed into transverse
ridges when the shell has been distorted by movement in the shale. In some of the
specimens in the sandy layers, a few concentric lines of minute puncte occur on the posterior
portion of the inner surface. A large ventral valve has a length of 15 mm. with a width of
10 mm., and a dorsal valve 11 mm. in length has a width of 8 mm. The average length of
several hundred specimens of the ventral valve is from 6 to 7 mm.

The cast of the area of the pedicle valve shows it to be rather long and well extended out
on the cardinal slopes. A clearly defined pedicle furrow divides it midway, and a narrow
flexure line occurs about halfway between the pedicle furrow and the outer margin. The area
is marked by fine striz of growth parallel to the margin. The area of the brachial valve is
short and seldom well preserved.

The cast of the interior of the valves, both in the argillaceous and sandy shale, shows almost
no traces of vascular markings or muscle scars.

Observations.—When studying this species in 1901 I had a few specimens which at the
time I considered to be identical with Lingulella bella (Walcott). During the season of 1901
S. Ward Loper collected many hundred specimens on McNeil Brook, and other localities in
Cape Breton, that clearly showed that Matthew [1901a, p. 273] was correct in assigning it to a
distinct species. I was not sure that his Lingulella lens (Matthew) was distinct, as the material
from which he described and figured it was badly crushed and broken, the fragments of shell
being embedded together in the limestone. None of the typical specimens show the apex of
the ventral valve. The one used in illustration by Matthew [1901a, Pl. V, fig. 3a] has all the
apex broken away, and the shell is somewhat compressed laterally. A photograph of this
specimen of Lingulella lens (Matthew) is reproduced in Plate XX XIII, figure 1.

Among the collections made by Loper, there are a large number of shells crushed and
crowded together very much as in the typical material of Linguleila lens used by Matthew.
There are, however, in the accompanying shales large numbers of individual specimens which
are beautifully preserved, which illustrate the outline and conyexity of the shell. The series
illustrates the growth of the shell, also the various forms in which it occurs owing to the differ-
ence in sediment in which it has been embedded. The material collected by Loper came from
several horizons of the Upper Cambrian. Matthew [1901a, pp. 273-274] assigns ‘‘Lingulella
concunna”’ to the Dictyonema zone, and “‘Lingula lens” to the Parabolina zone.

The shells in the arenaceous shales on McAdam shore are clearly Lingulella concinna,
but in the calcareous layers the shells are different and I retain the name Jens for them.

I received from Dr. G. Lindstrém a specimen from the black Dictyonema shales of Skane,
Sweden, labeled ‘‘Lingulella nathorsti Linnarsson.” This is evidently an accident, as that
species occurs only in the Lower Cambrian and the specimen is a broader shell much like that
of L. concinna of Cape Breton. With our present information it is provisionally referred to
LL. conevnna.

ForMATION AND LOCALITY.—Upper Cambrian: (8h) Shale and shaly limestone on McNeil Brook, 1.5 miles (2.4
km.) east of Marion Bridge; (807 [ Matthew, 1903, p.204)) shales of Division C3cof Matthew on McLeod Brook (=Barachois
River); (10c) shales on west side of Barachois River; (10n) shale in ravine on east side of Barachois Glen, 3 miles (4.8 km.)
from Barachois; (10e, 10f, 10g, and 10h) shale on small east branch of Barachois River, about 0.75 mile (1.2 km.) north
of the crossroad from Boisdale to Upper Leitches Creek; (8d and 372) shale at Upper Leitches Creek; (10m and 372a)

shale 2 miles (3.2 km.) south of the Boisdale Road from Upper Leitches Creek; (10d and 10i) shale in high bank on
west side of Barachois River, just north of the Boisdale Road; (13h) shale on east bank of Barachois River, 1.5 miles

488 CAMBRIAN BRACHIOPODA.

(2.4 km.) north of Boisdale; (101) shale on east bankof Barachois River, 6 miles (9.6 km.) from Little Bras d’Or Lake;
(3q) shale in Barachois Glen, 4 miles (6.4 km.) south of Little Bras d’Or Lake; (8p and 372b) shale in ravine 0.5 mile
(0.8 km.) north of McMullins, on the crossroad to Boisdale; (160) shales on McMullins Brook, in the east Boisdale
district; (30 and 372c) shale in ravine east of the railroad, just south of Barachois; and (372d) shale on McAdam
shore on East Bay, east of Bras d’Or Lake; all in eastern Cape Breton, Nova Scotia.

Middle Cambrian: (3i) Compact, fine-grained, thin-bedded, gray sandstone of the Paradoxides zone, on McLean
Brook, 1 mile (1.6 km.) east of McCodrum Brook and 1.5 miles (2.4 km.) west of Marion Bridge, eastern Cape
Breton, Nova Scotia.

A specimen from the following locality is provisionally referred to Lingulella coneimna:

Upper? Cambrian: (310h) Shale collected somewhere (probably Fogelsang), in the old Province of Skane, now
the Provinces of Malméhus and Christianstad, Sweden.

LINGULELLA CUNEOLA (Whitfield).

Plate X XVII, figures 7, 7a-b.

Lingulepis cuneolus WartrIeLp, 1877, U. S. Geog. and Geol. Survey Rocky Mtn. Region, Rept. Geology Black Hills
of Dakota; Prelim. Rept., pp. 8-9. (Described and discussed as below as a new species.)
Lingulepis cwneolus WaitFIE1D, 1880, U.S. Geog. and Geol. Survey Rocky Mtn. Region, Rept. Geology and Resources
Black Hills of Dakota, by Newton and Jenney, p. 336, Pl. II, figs.5 and 6. (Description copied from preceding
_reference. The specimen represented by fig. 6 is redrawn in this monograph, Pl. XX VII, fig. 7.)
Obolus (Lingulella) cuneolus (Whitfield), Wancorr, 1899, Mon. U.S. Geol. Survey, vol. 32, pt? 2, p. 443. (Merely
changes generic reference.)

The original description by Whitfield follows:

Shells small, rather below the medium size, triangularly ovate in outline or sometimes subcuneate; ventral valve
triangularly ovate, with a sharp somewhat pointed beak, the width and length about as three and four, and the point of
greatest width near the lower third of the length of the valve; cardinal slopes abrupt, scarcely convex; basal line
rounded at the sides, but nearly straight in the middle; surface of the valve strongly convex, becoming almost sub-
angular in the upper part; dorsal valve much shorter proportionately than the ventral, the length but little exceeding
the width; side and base more rounded and the beak truncate; surface distinctly convex.

Surface of the shell apparently smooth, but usually exfoliated, in which condition a few fine radiating lines are
visible.

This shell differs from L. pinnaformis Owen im size and in the more distinctly cuneate form of the ventral valve.
At first sight it might be taken for the young of that species, but a little critical examination soon reveals marked dis-
tinctions in the truncation of the front margin, and especially in the form of the cardinal slopes, which are rounded
and never concave, as in almost all ventral valves of that species. In consequence of this latter feature the beak does
not appear so attenuated as in that one, although proportionately quite as long. In the general surface characters and
form of the valves it corresponds with the genus Lingulepis, although we have not been able to distinguish the muscular
impressions.

Were it not for the difference in the size of the shells we should be inclined to think this might be the species
figured by Messrs. Meek and Hayden [1865, p. 3, Pl. I, figs. la-b] as Lingulepis dakotensis; but as their figures appear
to be of the natural size, we should suppose es to me very distinct, as all the specimens of our shell noticed have been
small, none exceeding one-fourth of an inch in length.

Observations—This species does not appear to be correctly referred to Lingulepis. In
outline it resembles some of the cuneate forms of Lingulella, and in its thick laminated shell it
approaches Lingulella phaon (Walcott) (Pl. X XVI). Like that species, it has a thick outer layer
and strong, radially striated inner layers, and numerous lamelle slightly oblique to the outer
layer over the anterior portions of the shell, especially about the anterior and lateral margins.
Most of the specimens are in the form of partial casts, only a portion of the outer shell adhering
to the cast.

The form of the ventral valve approaches that of some of the broader shells of Lingulella_

perattenuata (Whitfield) (Pl. XXI). It differs, however, in being more cuneate. Except for
the somewhat straighter slope of the sides toward the beak it might be identified with Lingulella
acutangula (Roemer) (Pl. XVII). Although fairly large collections were made from the Cam-
brian formations in the Black Hills during the field season of 1897, no specimens were found
that could be definitely identified as belonging to this species, the only material available for
study being that in the original collections of W. P. Jenney.

FORMATION AND LOCALITY.—Middle Cambrian: (355) Sandstones in Red Canyon Creek, southwest side of the
Black Hills, South Dakota.

OBOLIDA. 489

Specimens somewhat doubtfully referred to this species occur at the following locality:

Middle Cambrian: (167) Sandstone beneath limestone and resting on the pre-Cambrian in a bluff 9 miles (14.4
kin.) west of Custer, Black Hills, South Dakota.

LINGULELLA DAMESI (Walcott).@
Plate XX-XIX, figures 8, 8a—c.

Obolus (Lingulelia) damesi Waucotr, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 329. (Characterized as below as a new

species. )

The general descriptions of Obolus chinensis (Walcott) (p. 387) and Lingulella prima (Hall)
(p. 526) apply so closely to this species that it does not appear necessary to do more than call
attention to the points in which they differ. From Obolus chinensis (P]. XX XIX) this species
varies in having a more elongate, acuminate ventral valve and a more ovate dorsal valve; the
valves are also less convex. From Lingulella prima (Pl. XXVI1) it differs in the more gradual
curvature of the sides from the apex to the front margin, in this respect resembling some varieties
of L. ferruginea Salter (Pl. XXIX). The average size of the ventral valve is about 5 mm. in
length by 3.5 mm. in width.

The specific name was given in honor of Dr. W. Dames.

FORMATION AND LOCALITY.—Middle Cambrian: (€7) Lower limestone member of the Kiulung group [Black-

welder, 1907, pp. 37 and 39 (last list of fossils), and fig. 8a (bed 33), p. 29], 2.2 miles (3.5 km.) southwest of Yenchuang;

and (€10) lower shale member of the Kiulung group |Blackwelder, 1907, pp. 87 and 40 (part of 8d list of fossils), and fig.
&a (bed 35), p. 29], about 3 miles (4.8 km.) southwest of Yenchuang; both in the Sintai district, Shantung, China.

A shell which may be a variety of this species occurs at the following locality:

Upper Cambrian: (C64) Upper limestone member of the Kiulung group [Blackwelder, 1907, pp. 37 and 42 (first
list of fossils), and fig. 10 (bed 20), p. 38], 2.7 miles (4.3 km.) southwest of Yenchuang, Sintai district, Shantung,
China.

LINGULELLA DAVIDSONI (Barrande).

Plate XXXII, figures 1, la-e.

Lingula davidsoni BARRANDE, 1879, Systéme silurien du centre de la Bohéme, vol. 5, Pl. CIV, figs. vu: 1-4. (Not
described, but figured as a new species. Pl. CIV, figs. vu: 1A, 1b, 3A, 3b, 4E, and 4 are reproduced in this
monograph, Pl. XXXII, figs. 1, la-e, respectively.)

In the absence of specimens for study an opinion of the generic relations of this fine species
is necessarily based on the illustrations given by Barrande. Comparing Plate XXXII, figures
1 and 1b, with Plate XVII, figure 1a, we note at once the similarity between Lingulella davidsont
and L. acutangula (Roemer) in their general form and the character of their areas as far as shown
for Lingulella davidsoni. Fragments of the exterior shell of the latter (Pl. XX XII, fig. 1b)
may be compared with the exterior surface of the former (Pl. XVII, fig. 1). The dark oval
spots in front of the area in figure 1d may be of importance, or they may represent only a depres-
sion on each side of the median ridge such as often occurs in compressed shells. If this species
is a typical Lingulella, it is one of the last of its race, occurring as it does in Etage d4 of
Barrande’s section.

The specific name was given in honor of Thos. Davidson.

FoRMATION AND LOCALITY.—Ordovician: (303m) Etage d4 at Lieben; (303n) Etage d4 at Wraz; and (8080)
Etage d4 at Lodenitz; all [Barrande, 1879b, Pl. CIV] in Bohemia, Austria-Hungary. :

LINGULELLA DAvist (McCoy).
Plate XXX, figures 2, 2a; Plate XX XI, figures 6, 6a-h.

Lingula sp. Davis, 1846, Quart. Jour. Geol. Soc. London, vol. 2, pt. 1, p. 70. (Mentioned only.)
Not Lingula ovata McCoy, 1846, Silurian Fossils of Ireland, p. 24, Pl. II, fig. 1. (Described and discussed. This
species is not taken up in this monograph.)

a Better preserved and more complete series of specimens of this species collected by Dr. J. P. Iddings, in Manchuria, indicate that the form
bears a closer relationship to Obolus than to Lingulella. In the volume on Paleontology of Willis’s work on Research in China (Carnegie Insti-
tution of Washington) the species will be described and figured under the title, Obolus damest (Walcott).

490 CAMBRIAN BRACHIOPODA.

Lingula sp. Sepewick, 1847, Quart. Jour. Geol. Soc. London, vol. 3, pt. 1, pp. 140, 143, and 147. (Mentioned only.)

Tellinomya lingule-comes McCoy [not Sauer], 1851, Annals and Mag. Nat. Hist., 2d ser., vol. 7, p. 56. (Described
and discussed. Salter’s species is not a brachiopod and is not taken up in this monograph.)

Lingula davisi McCoy, 1851, idem, vol. 8, pp. 405-406. (Described and discussed as a new species.)

Lingula davisi McCoy, 1854, British Paleozoic Fossils, p. 252, Pl. IL, figs. 7, 7a-b. (Description copied from preceding
reference and one locality added.) u

Lingula ovata McCoy (in part), 1854, idem, p. 254, Pl. IL, figs. 6 and 6a. (Described and discussed. Specimens of
Lingulella davisi were included with ‘‘Lingula ovata” in this description. The specimens belonging with
Lingula ovata are not taken up in this monograph.)

Tellinomya lingulicomes McCoy [not Saurmr], 1854, idem, p. 274, Pl. TX, fig. 18. (Described and discussed almost as
in McCoy, 1851a, p. 56.)

Lingulella davisi (McCoy), Sauter, 1866, Mem. Geol. Survey Great Britain, vol. 3, pp. 333-3834, Pl. II, figs. 7-12, Pl.
IV, figs. 14 and 14a. (Described in Latin and discussed in English.)

Lingulella davisii (McCoy), Davipson, 1866, British Fossil] Brachiopoda, vol. 3, pt. 7, No. 1, pp. 56 and 57, Pl. IV,
figs. 1-16. (Described and discussed. Figs 9, 3, 7,6, 4,5, 13, 14, and 15 are copied from Salter, 1866b, Pl. II,
figs. 7-12, and Pl. IV, figs. 14 and 14a, respectively. Figs. 10, 11, and 12 are reproduced in this monograph, Pl.
XXXI, figs. 6, 6a-b, respectively.)

Lingulella davisii (McCoy), Saurer, 1867, Siluria, by Murchison, 4th ed., pp. 44 (and footnote) and 52; fossils (5)
fig. 1; fossils (10), fig. 11. (Mentioned.)

Lingulella davisi (McCoy), Davison, 1868, Geol. Mag., vol. 5, pp. 304 and 306, Pl. XV, figs. 13-15. (Species discussed.)
Lingulella davisi (McCoy), Muxrx, 1871, Proc. Acad. Nat. Sci. Philadelphia for 1871, vol. 23, pp. 186-187, fig. 2, p. 185.
(Discussed in discussion of ‘‘Lingulella lambormi.” Tig. 2 is copied from Davidson, 1866, Pl. IV, fig. 14.)
Lingulella davisii (McCoy), Hatt, 1873, Twenty-third Ann. Rept. New York State Cab. Nat. Hist., Pl. XIII, fig. 4

(No text reference. Fig. 4 is copied from Davidson, 1866, Pl. IV, fig. 16.)

Lingulella davisti (McCoy), Roemer, 1876, Lethza geognostica, pt. 1, Lethza paleeozoica, Atlas, Pl. II, figs. 5a-c.
(No text reference.) :

Lingulella davisii (McCoy), Sauter and ErnErinGE, 188], Mem. Geol. Survey Great Britain, vol. 3, 2d ed., pp. 537-538,
Pl. II, figs. 7-12; Pl. IV, figs. 14 and 14a. (Copied from Salter, 1866b, p. 333, Pl. IT, figs. 7-12; Pl. IV, figs.
14 and 14a.)

Lingulella sp. Kayser, 1883, China, by Richthofen, vol. 4, pp. 35-36, Pl. III, fig. 3. (Described in German. Fig.
3 is reproduced in this monograph, Pl. XXX, fig. 2a.)

Lingulella davisi (McCoy), Hatt and CrarKke, 1892, Eleventh Ann. Rept. State Geologist New York for 1891, p. 232,
fic. 239. (No text reference, figure copied from Salter, 1866b, Pl. IV, fig. 14a.)

Lingulella davisi (McCoy), Hatt and CrarKe, 1892, Forty-fifth Ann. Rept. New York State Museum for 1891, p. 548,
fig. 239. (Copy of preceding reference.)

Lingulella davisi (McCoy), Haut and CuarKe, 1892, Nat. Hist. New York Paleontology, vol. 8, pt. 1, pp. 56 and 57,
fic. 18. (Discussed in the text and figure copied from Salter, 1866b, Pl. IV, fig. 14a.)

Lingulella cf. davisit (McCoy), Kayser, 1897, Zeitschr. Deutsch. geol. Gesell. for 1897, Bd. 49, Heft 2, No. 2, p. 280, PI.
VII, fig. 6. (Characterized. Fig. 6 is reproduced in this monograph, Pl. XXX, fig. 2.)

Obolus (Lingulella) davisii (McCoy), Waxcort, 1898, Proc. U.S. Nat. Mus., vol. 21, pp.394 and 395, Pl. XX VII, figs. 1-5.
(Mentioned in discussion of genus Lingulella. The specimens represented by figs. 1, 2, 4, and 5 are redrawn in
this monograph, Pl. XXX, figs. 6f, 6d, 6e, and 6h, respectively.)

Linguleila cf. davisti (McCoy), MatruEw, 1902, Bull. Nat. Hist. Soc. New Brunswick, vol. 4, pt. 5, No. 20, pp. 407-408.
(Described.)

Tingulella cf. davisii (McCoy), Matrrew, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, p. 203.
(Copied from preceding reference.)

The characters of this species, as far as known to me, are illustrated on Plate XX XI, and
reference is made to some of them in the description of the genus Lingulella. Many interest-
ing observations are given by Davidson [1866, p. 57] in his description of the species and its
occurrence at various localities in Wales.

EK. Kayser [1897, Pl. VII, fig. 6] illustrates a dorsal? valve from the Cambrian beds of Iruya,

- Province of Salta, Argentina, which he compares with Lingulella davist. The specimen indicates
the presence of a form that may be the representative of L. davisi, but it may be a new form,
or possibly identical with some one of the species of the Atlantic basin fauna found m New
Brunswick or Newfoundland. The original figure is reproduced on Plate XXX, figure 2

The form illustrated by Kayser [1883, Pl. III, fig. 3] in the report on the Cambrian brachi-
opods of Liaotung is also suggestive of Lingulella davisi, as may be seen by comparing a copy
of Kayser’s figure on Plate XXX with the illustration of L. davisi on Plate XX XI, figure 2a.

OBOLIDA. 491

It should also be compared with Lingulella ampla (Owen) (Pl. XXVIII, figs. 1, 1a—j) of the
Mississippi Valley.

The specific name was given in honor of Mr. J. E. Davis, who first called attention to the
species. Q

ForRMATION AND LOCALITY.?— Ordovician : (304n) “‘Coniston (Bala) limestone” [McCoy, 1854, p. 254], at Coniston,
Lancashire, England.

Upper Cambrian: (366d) Lower Lingula flags at Carnedd Filiast, Bangor; (366e) Lower Lingula flags at Marchillyn-
mawr, Llanberis; both [Davidson, 1866, p. 57] in Carnarvonshire, North Wales.

Lower Lingula flags at the following localities: (866f) Ffestiniog; (366g) Dolgelly; (366h) Pen-y-Bryn, 5 miles (8 km.)
north of Dolgelly; (866i) Llyn Dywarchen; (366j) Pont Nant-y-Lladron, on the Bala Road; (366k) Penmorfa; (3661)
Tremadoc ; and (366m) near Nant-y-Groes, west of Bala; all [Davidson, 1866, p. 57] in Merionethshire, North Wales.

(866n) Lower Lingula flags at Portmadoc; (3660) “Bala schists” [McCoy, 1854, p. 254] at Bryn Melyn, near Bala;
(3866p [ Davidson, 1866, p. 57]) Upper Tremadoc beds at Deudraeth; (3664 [Davidson, 1866, p. 57]) Upper Tremadoc beds
at Garth, opposite Portmadoc; and (366a) upper portion of Middle Lingula flags, 6 miles (9.6 km.) east of Ffestiniog; all
in Merionethshire, North Wales.

(366r) Shale 2 miles (3.2 km.) north of Builth, Brecknockshire; and (366 [ Davidson, 1866, p.57]) at Whitesand Bay,
near St. Davids Head, Pembrokeshire; both in South Wales.

(318m [Davidson, 1866, p. 57]) Near the base of the lower black slates, in the Waterfall Valley near Maentwrog,
North Wales.

(307a [Matthew, 1903, p. 203]) Shales of Division C3c2 of Matthew on McLeod Brook (~Barachois River), near Bois-
dale, eastern Cape Breton, Nova Scotia, Canada.

(889d [Kayser, 1897, p. 280]) Iruya, Province of Salta, Argentina, South America.

(882 [Kayser, 1883, p. 35]) Limestones at Saimaki, Liaotung, China.

( LINGULELLA DELGADOI 0. sp.
Plate XXIX, figures 6, 6a-c.

Langulepis acuminata meeki DELcavo [not Waxcorr], 1904, Communica¢des Commissio Servigo Geol. Portugal, tome 5,
fasc. 2, pp. 366-367, Pl. IV, figs. 17 and 27; Pl. VI, fig. 9. (Characterized and discussed in French. A photo-
graph of the specimen represented by fig. 27 (reverse view) is reproduced in this monograph, Pl. XXIX,
fig. 6b.)

Lnngulella granvillensis DeLeavo [not Watcorr], 1904, idem, pp. 367-368, Pl. IV, figs. 15, 16,18,and 19. (Discussed in
French. Photographs of the specimens represented by figs. 16 and 18 are reproduced in this monograph,
Pl. XXIX, figs. 6 and 6a, respectively.)

Lingulella ferruginea Devcano [not Sarrer], 1904, idem, pp. 368-369, Pl. IV, figs. 20 and 21; Pl. VI, fig. 2. (Discussed
in French.) : 5

Lingulella cf. linguloides Matthew, DELGavo, 1904, idem, pp. 369-370, Pl. IV, fig. 14. (Described and discussed in
French. A photograph of the specimen represented by fig. 14 (reverse view) is reproduced in this monograph,
Pl. XXIX, fig. 6c.)

This is one of the abundant and variable forms in the fauna of the Province of Alemtejo.
It may be compared in this respect with the widely distributed Lingulella ferruginea Salter.
Delgado,compares different phases of it to three species, two of which, ZL. ferruginea Salter and
L. cf. linguloides Matthew, I think are specifically the same. Lingulella granvillensis Walcott
has the same flattening along the median line of the ventral valve. As stated by Delgado
[1904, p. 367], there is a strong resemblance between the representatives of the two forms, but I
think that it is better to give the Portuguese form a distinct specific name than to identify it
with the American species.

Delgado sent me enlarged photographs of the specimens of the three varieties which he
recognized and illustrated, and I have reproduced four of them, Plate X XIX, figures 6, 6a-c.

It is quite probable that if I had all of Delgado’s specimens to study a different disposition
would be made of the specific references, but with present knowledge and experience of the
variability of species like this, especially where the shells have been more or less misshaped by
lateral movement in the “schists,” I prefer to combine the forms in one species.

The specific name is given in honor of the late Dr. J. F. Nery Delgado.

ForMATION AND LOCALITY.—Lower Cambrian: (351 [Delgado, 1904, pp. 366-369]) Shales at Monte de Valbom,
northeast of Villa Boim, Province of Alemtejo, Portugal.

a The species also occurs in Locality 317b (p. 248).
b Davidson does not state which of the three localities (866k, 366 1, or 366m) is the type.

492 CAMBRIAN BRACHTOPODA.

L ' LINGULELLA DESIDERATA (Walcott).
Plate XX, figures 4, 4a-c, 5, 5a-j.

Obolus (Lingulella) desideratus Watcott, 1898, Proc. U. S. Nat. Mus., vol. 21, pp. 399-400. (Described and discussed
as & new species.)

Obolus (Lingulella) desideratus WaxLcorr (in part), 1899, Mon. U.S. Geol. Survey, vol. 32, pt. 2, pp. 445-446, Pl. LX,
fig. 2 (not 2a). (Described essentially as below, and discussed. The specimen represented by fig. 2 is redrawn
in this monograph, Pl. XX, fig. 4. The specimen represented by fig. 2a is referred in this monograph to Obolus
rotundatus, Pl. XX, fig. 2e.)

Dicellomus nanus Waxtcorr (in part) {not Menx and Haypen], 1899, idem, p. 447, Pl. LX, fig. 3 (mot figs. 3a—d).
(Mentioned. The specimen represented by fig. 3 is redrawn in this monograph, Pl. XX, fig. 5j. The speci-
mens represented by figs. 3a-d are referred in this monograph to Dicellomus nanus.)

Shell small, subovate, with the ventral valve obtusely acuminate, and the dorsal valve
broadly ovate. Valves are strongly convex, with the ventral valve fully as much so as the
dorsal. There is a slight variation in the outline of the valves, some being slightly more
rounded posteriorly than others.

The surface of the shell is marked by fine, concentric lines of growth, and between them
very fine, slightly irregular strive; a few rather narrow indistinct undulations radiate from
the umbo toward the front and lateral margins; when the outer shell is partly exfoliated the
outer surface of the inner layer is marked by very fine indistinct radiating striz; there are a
few traces of small, scattered pits or punctze on the inner surface. The shell is thin and formed
of an outer layer and one or more inner layers or lamelle.

The average length of the ventral valve is about 4 mm.; width, 3 mm. A dorsal valve
3.5 mm. long has a coal of 3 mm.

A cast of the interior of a ventral valve shows an area of medium length, divided midway

by a narrow, clearly defined pedicle groove. The area of the dorsal <alme | is short. Nothing,
is known of the interior of the ventral valve, but in a cast of a dorsal valve-there are traces
of the main vascular sinuses, central median septum, and the central muscle scars.

Observations.—This species may be compared with the Middle Cambrian Lingulella ferru-
ginea Salter of the Atlantic basin faunas, and L. similis (Walcott), of the Black Hills, upper
Mississippi Walley, and Appalachian faunas. Lingulella similis is more convex and narrower,
and L. manticula (White) is considerably more acuminate. Compared with the Rocky Moun-
tain species it is termediate between L. manticula and L. rotunda (Matthew). It may also be
compared with L. granvillensis Walcott of the Olenellus fauna of eastern New York, and ZL.
tole (Billings) of the Lower Ordovician fauna of Newfoundland. It is distinguished from
L. granvillensis by its more regularly rounded anterior margin.

The specimens represented by Plate XX, figures 4b, 4c, and 5j, are broader proportionately
than the typical specimens represented by Plate XX, figures 4 and 4a, but they occur at the
same geological horizon in the Eureka district, Nevada. What appears to be the same, or a
closely related species, occurs in the upper beds of the Secret Canyon shale in the Eureka dis-
trict, Nevada.

A form that appears to be identical occurs in considerable abundance in Alabama and
Tennessee. The similarity in form between the specimens from Wyoming and Nevada, and
those from Alabama and Tennessee is shown by Plate XX, figures 4, 4a-c, of the typical
specimens, and Plate XX, figures 5, 5a-i, of their representatives in the Appalachian region.
This similarity is even more striking when the specimens are compared directly with one another,
and some allowance made for the fact that the Appalachian specimens have all been more or
less compressed.

Asmall shell that appears to be identical with this species qccurs in the red sandstone
and argillaceous shale of the Lower Ordovician of Colorado. The specimens from Trout Creek,
below Bergen Park, are much like those from the Gallatin Range in Montana and the same
species of Bullingsella is associated with them. At Cement Creek, 10 miles-(16.1 km.) south-
east of Crested Butte, Colorado, the shells occur in a fine conglomerate and coarse sandstone

OBOLIDA. 493

associated with a species of Bathyurus much like that from the beds containing Lingulella
desiderata at Trout Creek.

FORMATION AND LOCALITY.—Lower Ordovician: (360) Red siliceous limestone near Colorado Springs; (186) near
line of contact between red and gray Ordovician limestones, in red siliceous limestone about 30 feet (9.1 m.) above
the pre-Cambrian rocks, Williams Canyon, Manitou; (187) red siliceous limestone 105 to 122 feet (32 to 36.7 m.) above
the pre-Cambrian rocks, 2 miles (3.2 km.) below Manitou Park Hotel; (360a) red siliceous limestone on west side of
Trout Creek, below Bergen Park, 7 miles (11.2 km.) north-northwest of Manitou; all in El Paso County, Colorado.

(360b) Red siliceous limestone on Cement Creek, 3 miles (4.8 km.) north of Hot Springs, Ouray County; and
(860c) red siliceous limestone about 10 miles. (16.1 km.) southeast of Crested Butte, Elk Range; both in Colorado.

Upper Cambrian: (161) Limestone on the south side of West Gallatin (Gallatin) River, northwest of Hamilton,
on the north side of the Gallatin Valley, Gallatin County, Montana.

(7x, 7y, and 7z) Limestone of the Emigrant formation [Turner, 1902, p. 265], ipo 2.5 miles (4 km.) southeast
of the summit of Emigrant Pass, Silver Peak quadrangle (U.S. Geol. Sueavep), Esmeralda County; (8n) limestone
about 500 feet (152 m.) up in the limestones east of Swallow Ranch, west side of Snake Range, 20 miles (32.2 km.)
south of Osceola, White Pine County; (313) limestone 0.75 mile (1.2 km.) east-northeast of McGill post office, White
Pine County; and (61) limestone in the Dunderberg shale [ Walcott, 1908f, p. 184], a little south of the Hamburg mine,
Eureka district [Hague, 1892, Atlas], Eureka County; all in Nevada.

(30h) About 350 feet (106.7 m.) above the Middle Cambrian and 2,950 feet (899.2 m.) below the top of the Upper
Cambrian near the base of the arenaceous limestones forming 2a of the Orr formation [Walcott, 1908f, p. 177]; and
(30j and 30k) 950 and 1,150 feet (289.6 and 350.5 m.) above the Middle Cambrian and 2,450 and 2,175 feet (746.8 and
662.9 m.) below the top of the Upper Cambrian, in the arenaceous shales and limestone forming le of the Orr forma-
tion [Walcott, 1908f, p. 176]; all on Orr Ridge, about 5 miles (8 km.) south of Marjum Pass, House Range [Walcott,
1908f, Pl. XIII], Millard County, Utah.

(15d)* Thin-bedded blue limestone near Cave Spring on the east side of the Fish Spring Range, about 4 miles
(6.4 km.) south of the J. J. Thomas ranch, Juab County; (34t) limestone 1.5 miles (2.4 km.) northwest of Wahwah
Springs, about 80 feet (24.4 m.) below the Highest point on the north side of the road at Cane Pass, Wahwah Moun-
tains, iene County; (82g) about 2,575 feet (784.9 m.) above the Cambrian quartzitic sandstones in a blue limestone
about 2 miles (3.2 km.) southeast a Muskrat Springs on the northwest face of Grantsville Peak, Stansbury Range,
Tooele County; (54j) about 700 feet (213.4 m.) above the Middle Cambrian and 525 feet (160 m.) below the top of the
Upper Cambrian in the arenaceous limestones forming 2c of the St. Charles formation [Walcott, 1908f, p. 192], in
Blacksmith Fork Canyon, about 10 miles (16.1 km.) east of Hyrum, Cache County; all in Utah.

(5a and 54t) Limestones of the St. Charles formation [ Walcott, 1908a, p. 6] about 250 feet (76 m.) above the Middle
Cambrian on the north side of Twomile Canyon, near its mouth, 2 miles (3.2 km.) southeast of Malade, Oneida County,
Idaho.

(93 and 980) Shales and limestones at the base of the Knox dolomite near Jordan’s, just below the ford on Cowan
Creek, about 8 miles (12.8 km.) southeast of Center; (93a) > same horizon as Locality 93 on Terrapin Creek road from
Center to Amberson; (940) same horizon as Locality 93, 0.25 mile (0.4 km.) beyond Givens Ford, on Cowan Creek, about
8 miles (12.8 km.) southeast of Center; and (94xx) same horizon as Locality 93 at Givens mill, on Cowan Creek, about
8 miles (12.8 km.) southeast of Center; all in Cherokee County, Alabama.

(361) Shaly limestone in suburb of Attalla, Etowah County, Alabama.

(96) Limestones near the ford on the Cedartown road, 1.5 miles (2.4 km.) south of Rome, Floyd County; and
(362) shales in the Oothkalooga Valley, Bartow County; both in Georgia.

(107u and 1070) Limestones and shales at the base of the Knox dolomite, west of the top of Copper Ridge, near
the Southern Railway cut, about 10 miles (16.1 km.) northwest of Knoxville [Keith, 1896b, areal geology sheet], Knox
County, Tennessee.

(122a)¢ Shale at the headwaters of Forgey Creek, northwestern part of the Greeneville quadrangle (U. S. Geol.
Survey), Hawkins County, Tennessee.

Upper? Cambrian: (56) Limestone at Sierra Springs, eastern base of Lookout Mountain, Eureka district [Hague,
1892, Atlas], Eureka County, Nevada.

Middle? Cambrian: (313c) Limestone about 12 miles (19.3 km.) west-southwest of Alpha Station, Eureka County,
Nevada.

Middle Cambrian: (57) Shaly Eldorado limestone [Walcott, 1908f, p. 184] at the 700-foot (213.4 m.) level of the
Richmond mine, Ruby Hill [Hague, 1892, p. 43, and Pl. I, opposite p. 116]; (57b) limestones at the north end of Mineral
Hill, just south of Ruby Hill [Hague, 1892, p. 43, and PI. I, opposite p. 116]; (60) limestones in upper beds of Secret
Canyon shale, across the canyon from the dump of the old Richmond mine shaft; and (58) shaly limestones in upper
beds of Secret Canyon shale, east side of New York and Secret canyons; all in the Eureka district [Hague, 1892, Atlas],
Eureka County, Nevada.

(318b) Limestone 3 miles (4.8 km.) morthenorifiesat of Schellbourne, Schell Creek Range, White Pine County,
Nevada.

a This species also occurs at Locality 34i (p. 196).
b The species is somewhat doubtfully identified from this locality.
e This species also occurs at Locality 122 (p. 2238).

494. CAMBRIAN BRACHIOPODA.

(15x) Limestones near the middle of the Fish Spring Range, near the line between Juab and Tooele counties;
and (15p) limestones near the north end of the Fish Spring Range, Tooele County; both in Utah.

(5b) Dark blue-gray Langston limestone [Walcott, 1908f, p. 198], just above the Cambrian quartzitic sandstones, on
the north side of Twomile Canyon, near its mouth, 2 miles (3.2 km.) southeast of Malade, Oneida County; (59f) lime-
stones immediately underlying the Spence shale member of the Ute limestone [ Walcott, 1908a, p. 8], in a saddle north
of the creek which flows into Mill Canyon from the west, about 5 miles (8 km.) aesinsernevrent of Liberty and 15
miles (24.2 km.) west of Montpelier, Bear Lake County; and (55e and 163) Spence shale member of the Ute limestone
[Walcott, 1908a, p. 8], about 50 feet (15.2 m.) above the Brigham quartzite and 2,755 feet (839.7 m.) below the Upper
Cambrian, in a ravine running up into Danish Flat from Mill Canyon, about 6 miles (9.6 km.) west-southwest of Lib-
erty and 15 miles (24.2 km.) west of Montpelier, Bear Lake County; all in Idaho.

(55e) Spence shale member of the Ute limestone about 100 feet (30.5 m.) above the Brigham quartzite [Walcott,
1908f, p. 197], at the mouth of the first small canyon south of Wasatch Canyon, east of Lakeview ranch, 5 miles (8 km.)
north of Brigham, Boxelder County, Utah.

(81land 54h) About 3,140 feet (957.1 m.) above the Brigham quartzite and 1,050 feet (320 m.) below the Upper
Cambrian in the limestones forming la of the Bloomington formation [Walcott, 1908f, p. 194]; and (541) about 500 feet
(152.4 m.) above the Brigham quartzite and 3,700 feet (1,127.8 m.) below the Upper Cambrian in the Spence shale
member of the Ute limestone [Walcott, 1908f, p. 197]; both in Blacksmith Fork Canyon, about 10 miles (16.1 km.) east
of Hyrum, Cache County, Utah.

(3021) Limestone in the Gallatin Range; and (302b) limestone near Crowfoot Ridge, Gallatin quadanele (U.S.
Geol. Survey); both in Yellowstone National Park, Wyoming.

(5f) Limestones interbedded in the Wolsey shale [Weed, 1900, p. 285], in Meagher County on the road to Wolsey,
about 4 miles (6.4 km.) south of the divide at the head of Sawmill Creek and 11 miles (17.7 km.) south of Neihart,
Little Belt Mountains quadrangle (U. S. Geol. Survey), Cascade County, Montana.

(581) About 1,830 feet (557.8 m.) above the Lower Cambrian in the limestone forming 3b of the Stephen formation
[Walcott, 1908c, p. 238(7)], on the east side of Mount Stephen about 3,000 feet (914.4 m.) above the Canadian Pacific
Railway track, 3.5 miles (5.6 km.) east of Field, British Columbia.

(88a) Limestone about 100 feet (30.5 m.) above the quartzitic sandstone at the base of the Cambrian, in the north-
ern suburbs of Deadwood, in the Black Hills, South Dakota.

(9) Limestone on southeastern slope of ridge 1 mile (1.6 km.) sity of the northwest corner of Harlans Knob,
about 4 miles (6.4 km.) northeast of Rogersville [Keith, 1905, areal geology sheet]; (9a) same horizon as locality No. 9
in limestone on the south shore of Holston River at Melinda Ferry, 5 miles (8 km.) southwest of Rogersville [ Keith,
1896a, areal geology sheet]; (101a and 101b) Rogersville shale near the schoolhouse, 3.5 miles (5.6 km.) southwest of
Rogersville, on the road to Melinda Ferry; (103b) third limestone south of the ridge of sandstone in the Rome formation
(“Town Knobs”’), on the road from Rogersville to Dodson Ford, near the line between the Morristown and Greeneville
quadrangles (U.S. Geol. Survey); and (121) Rogersville shale, road just east of Harlan Knob, 4 miles (6.4 km.) northeast
of Rogersville [Keith, 1905, areal geology sheet]; all in Hawkins County, Tennessee.

(117) Shales on the road north from Greeneville, Greene County, Tennessee.

(369g) Shales at Bonneterre, St. Francois County, Missouri.

(90b) Conasauga limestone, in cut on the Louisville and Nashville Railroad, near Woodstock, Bibb County;
(16) Conasauga (“‘Coosa”) limestone, Blountsville Valley, Blount County; and (139) limestone on Hokes Bluff road,
north of the chert outcrop, 5 miles (8 km.) east of Gadsden, Etowah County; all in Alabama.

Specimens somewhat doubtfully referred to this species occur at the following locality:

Middle Cambrian: (107a) Shale in railroad cut in Bull Run, northwest of Copper Ridge | Keith, 1896b, areal geology
sheet], 11 miles (17.7 km.) northwest of Knoxville, Knox County, Tennessee.

LINGULELLA DUBIA (Walcott).

Plate XXIV, figures 4, 4a.

Lingulella ella Waucort (in part) [not Hatt and Wurrrrerp], 1886, Bull. U. S. Geol. Survey No. 30, pp. 97-98, PI.
VIII, figs. 4b and 4c (not Pl. VII, fig. 2, or Pl. VIII, figs. 4, 4a, 4d, and 4e). (Original description, Hall and
Whitfield, 1887, p. 232, copied and species described and discussed. The specimens represented by figs. 4b
and 4c are redrawn in this monograph, Pl. XXIV, figs. 4 and 4a, respectively. The specimens represented by
Pl. VII, fig. 2, and Pl. VIII, figs. 4, 4a, 4d, and 4e, are referred in this monograph to Obolus ( Westonia) ella.)

Lingulella ella Waucort (in part) [not Hatt and Wurrriep], 1891, Tenth Ann. Rept. U.S. Geol. Survey, p. 607, Pl.
LXVII, figs. 2c-d (not figs. 2, 2a-b). (Mentioned. Figs 2c and 2d are copied from Walcott, 1886b, Pl. VIII,
figs. 4c and 4b, respectively. The specimens represented by figs. 2c and 2d are redrawn in this monograph, Pl.
XXIV, figs. 4 and 4a, respectively. The specimens represented by figs. 2, 2a-b, and 2e are referred in this
monograph to Obolus ( Westonia) ella.)

Lingulella ella Haut and Crarkx (in part) [not Hatt and Wurrrietp], 1892, Nat. Hist. New York, Paleontology, vol.
8, pt. 1, p. 58, fig. 20 (not figs. 19 and 21). (Mentioned in the text. Fig. 20 is copied from Walcott, 1891a, Pl.
LXVII, fig. 2c. The specimens represented by figs. 19 and 21 are referred in this monograph to Obolus ( Westonia)
ella.)

OBOLIDA. 495

Obolus (Lingulella) dubius Waxcorr, 1898, Proc. U. 8. Nat. Mus., vol. 21, p. 401. (Described and discussed essen-
tially as below as a new species.)

Lingulella genet Pacx, 1906, Jour. Geology, vol. 14, No. 4, p. 295, Pl. I, figs. 3, 3a-b. (Described and discussed as a
new species. )

This is a small shell associated with Obolus ( Westonia) ella (Hall and Whitfield). It occurs
in the form of casts in argillaceous shale, no traces of the shell substance remaining. The
ventral valve averages about 3 mm. in length, and the dorsal valves are a little shorter. A
cast of the interior of the ventral valve shows the visceral cavity (v), and an unusually strong
main vascular smus (vs) on each side. Only one specimen shows these characters as illustrated
by Plate XXIV, figure 4; others only faintly indicate them.

This dorsal valve is rounded ovate, and the cast of its interior shows a very short area
that extends well out on the cardinal slopes. The interior markings are a portion of the main
vascular sinuses, which, in their form and extension, somewhat resemble those of the dorsal
valve of O. ( W.) chuarensis (Walcott). The only muscle scars preserved are the anterior laterals
of the dorsal valve.

As far as can be determined from the casts, the outer surface is marked by lines of growth
and fine, slightly undulating concentric striz.

Observations.—At first I thought the specimens now referred to this species were the young
Obolus ( Westomia) ella, and so illustrated them [1891a, Pl. LX VII, figs. 2c and 2d]. There is
still considerable doubt as to their specific relations, but in view of the very distinct interior
markings I have referred them to a new species.

The form described by F. J. Pack [1906, p. 295] as “‘Lingulella genei”’ comes from the same
locality and band of shale as L. dubia, and has the same form and strong interior markings.
Some of Pack’s specimens show the cast of the exterior surface. This is marked by the very
fine, concentric, slightly undulating lines so typical of Lingulella. The best-preserved casts of
the surface do not present the characteristics of the surface of Obolus ( Westonia) ella.

FoRMATION AND LOCALITY.—Middle Cambrian: (81) Shales at the Chisholm mine, southwest slope of Ely Mountains;
and (333 [Pack, 1906, p. 295]) shales on the dump of the Abe Lincoln mine; both near Pioche, Lincoln County, Nevada.

We LINGULELLA ELLSI (Walcott).

Plate XIX, figures 3, 3a-c.
Obolus (Lingulella) ellsi Waucott, 1898, Proc. U. S. Nat. Mus., vol. 21, p. 402. (Described and discussed as below
as a new species. )

Shell small, broad ovate in outline, with the ventral valve obtusely acuminate, and the
dorsal valve broadly rounded; valves appear to have been moderately convex, judging from
their appearance in the siliceous shale. The surface of the shell is marked by rather strong,
concentric lines and striz of growth, the striz apparently indicating a slightly lamellose surface;
very fine radiating striz occur on the surface of the mner layers of the shell. A ventral valve
3.5 mm. in length has a width of 2.75 mm.; the dorsal valve is a little shorter than the ventral
valve.

Partial casts of the interior of the ventral valve show a very clearly defined area that
extended as a shelf on each side of the rather deep, narrow, pedicle furrow; portions of the
casts that fill the undercut may be observed in several specimens; the flexure lines are narrow,
sharp, and situated well out toward the lateral margins. The cast of the visceral area of the
ventral valve extends about one-third the distance from the area to the anterior margin; it is
not well defined, and no traces of muscle scars have been detected; of the vascular system
only the base of the main sinuses is shown in any of the casts.

Observations.—This very pretty little species is closely related in form to Lingulella rotunda
(Matthew), and comparison should also be made with the more rotund variety of L. ferruginea
Salter. It occurs in association with Acrothele pretiosa (Billings).

496 CAMBRIAN BRACHIOPODA.

The specific name is given in honor of Dr. R. W. Ells, whose fine work on the geology of a
portion of the Province of Quebec unraveled the stratigraphic relations of the Lauzon slates in
which the species occurs. Doctor Ells guided me to the locality at which the species ozcurs.

ForMATION AND LOCALITY.—Ordovician: (220a) Shales of the ‘‘Upper Sillery’’ (Lauzon of Logan), on Chaudiere
River at the Grand Trunk railroad bridge, Province of Quebec, Canada.

LINGULELLA FERRUGINEA Salter.
Plate X XIX, figures 1, la—w, 2, 2a-f ; Plate XXX, figure 1; Plate X X-XI, figures 3, 3a-c; Plate XX XV, figures 4, 4a-b.

Lingulella unguiculus Sauter, 1866, Rept. British Assoc. Adv. Sci. for 1865, p. 285. (Mentioned ima list of fossils
from the ‘‘Meneyian group.”’)

Lingulella ferruginea Saver, 1867, Quart. Jour. Geol. Soc. London, vol. 23, pt. 1, p. 340, fig. 1. (Described by Salter
as a new species in the paper by Salter and Hicks, see p. 497 for copy. Fig. 1 is reproduced in this monograph,
Pl. XXIX, fig. 2b.)

Lingulella ferruginea ovalis Hicks, 1867, idem, p. 341, figs. 2 and 3, p. 340. (Characterized by Hicks as a new
variety, and discussed by Salter and Hicks, in the paper by Salter and Hicks. Figs. 2 and 3 are reproduced
in this monograph, Pl. X XIX, figs. 2 and 2a, respectively. )

Lingulella ferruginea Salter, Davrpson, 1868, Geol. Mag., vol. 5, pp. 306-307, Pl. XV, figs. 1-8. (Described and dis-
cussed. Figs. 7a and 6a are reproduced in this monograph, Pl. X XIX, figs. 2c and 2d, respectively.)

LInangulella ferruginea ovalis Hicks, Davipson, 1868, idem, p. 307. (Mentioned in discussion of L. ferruginea.)

Lingulella ferruginea Salter, Davipson, 1871, British Fossil Brachiopoda, vol. 3, pt. 7, No. 4, pp. 336-337, Pl. XLIX,
figs. 32-35. (Described and discussed, see p. 497 for copy of part of discussion. Figs. 35a and 33a are repro-
duced in this monograph, Pl. X XIX, figs. 2e and 2f, respectively.)

Lingula or Lingulella sp. Linnarsson, 1876, Bihang till K. svensk. Vet.-Akad. Handl., Bd. 3, No. 12, pp. 15-16,
Pl. III, figs. 24-28. (Described and discussed in English. Fig. 28 is reproduced in this monograph, Pl. XX XI,
fig. 3c.)

Lingulella sp. undt. Linnarsson, 1879, Sveriges Geol. Undersékning, Afhandl. och uppsatser, Ser. C, No. 35, p. 25,
Pl. ILI, figs. 38 and 39. (Described in Swedish.)

Lingulella ferruginea Salter, Sauter and Erurrrmesn, 1881, Mem. Geol. Survey Great Britain, vol. 3, 2d ed., p. 538.
(Occurrence mentioned. )

Lingulella ferruginea Salter, Davrpson, 1883, British Fossil Brachiopoda, vol. 5, pt. 2, Pl. XVII, fig. 35. (No text
reference. )

Lingula? dawsoni MartHew, 1884, Manuscript name requested by Walcott.

Lingula? dawsoni Matthew, Watcorr, 1884, Bull. U. S. Geol. Survey No. 10, p. 15, PI. V, fig. 8. (Described and dis-
cussed as a new species, see p. 497 for copy. The specimen represented by fig. 8 is redrawn in this monograph,
Pl. XXIX, fig. 1d.)

Lingulella dawsoni MarruEw (in part), 1886, Trans. Roy. Soc. Canada for 1885, vol. 3, sec. 4, No. 3; pp. 33-34, Pl. V,
fig. 9d (not figs. 9, 9a-c). (Described and discussed as a new species, but refers in synonymy to preceding
reference. The specimen represented by fig. 9d is redrawn in this monograph, Pl. X XIX, fig. 1. The speci-
mens represented by figs. 9, 9a—c are referred in this monograph to Lingulella martinensis.)

Lingulella linguloides Martanw, 1886, idem, p. 34, Pl. V, figs. 8, 8a-b. (Described and discussed as a new species.

The two specimens represented by figs. 8, 8a—b are redrawn in this monograph, Pl. X XIX, figs la, 1b, and Ie, :

respectively. )

Obolella? gemmula MartHew, 1892, Trans. Roy. Soc. Canada for 1891, vol. 9, sec. 4, No. 5, pp. 41-42, Pl. XII, figs.
8a-c. (Described and discussed as a new species. The specimens represented by figs. 8b and 8c are redrawn
in this monograph, Pl. X XIX, figs. lu and lv, respectively.)

Lingulella dawsoni (Matthew), Hatt and CuarKks, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, p. 58, Pl. IT,
fig. 5. (Mentioned in text. Fig. 5 is drawn from the specimen figured by Matthew, 1886, Pl. V, fig. 9d.)
Lingulella cf. ferruginea Salter, Kayser, 1897, Zeitschr. Deutsch. geol. Gesell., Bd. 49, Heft 2, No. 2, p. 280, Pl. VII,

fie. 7. (Characterized and discussed in German. Fig. 7 is reproduced in this monograph, Pl. XXX, fig. 1.)

Obolus (Lingulella) gemmulus (Matthew), Waxtcort, 1901, Proc. U. 8. Nat. Mus., vol. 23, p. 673. (Merely changes
generic reference.)

Leptobolus cf. linguloides MatrHEew, 1902, Bull. Nat. Hist. Soc. New Brunswick, vol. 4, pt. 5, No. 20, p. 407. (De-
scribed.) A

Leptobolus linguloides MartHEWw, 1902, idem, p. 407. (Merely changes generic reference.)

Lingulella ferruginea Salter, MarrHew, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, p. 108. (Dis-
cussed in description of *‘Leptobolus atavus.’’)

Leptobolus gemmulus MatrHew, 1903, idem, pp. 190-192, Pl. XIV, figs. la-c. (Original description, Matthew 1892,
p. 41, copied, revised, added to, and discussed.)

Leptobolus cf. linguloides MartHew, 1903, idem, pp. 192-193. (Copy of Matthew, 1902b, p. 407.)

Leptobolus linguloides MatTHEW, idem, p. 193. (Merely changes generic reference.)

—_—s Ue

OBOLIDA. 497

The original description by Salter [Salter and Hicks, 1867, p. 340] is as follows:

Leneth fully 2.5 lines. Form ovate-oblong, the front rather obtuse, but not straight edged; the sides nearly
parallel; the obtusely pointed beak includes an angle of about 75°. Generally convex, especially down the median
area; the sides beveled obliquely; the surface concentrically and very finely striated; the inner surface rather coarsely
sulcate concentrically, indicating close ridges or sharp waves of growth upon the outer surface (not visible in our
specimens). The inner surface (and probably the outer) shows radiating lines (rather coarse ones) over the median
area, but not on the sides. ;

The pedicle groove is so wide and pyramidal as to open at an-angle of 40°; and its edges are so strongly pronounced
as to give the appearance of hinge plates. A short median ridge divides this area, and extends but a very short
distance. A specimen, apparently of the shorter valve, has also a median line, but fainter and longer. This is
uncertain, the specimen being much crushed.

The foregoing description was followed by a description of a variety named ovalis by
Hicks [Salter and Hicks, 1867, p. 341]. It was collected in the Red Rocks of the Menevian
group near St. Davids, and the varietal name was given to it on account of the front edge
being ‘rounded off, and not squared at all.” Davidson [1868, p. 307] stated that he did not
consider this character of any importance, as he had before him specimens of L. ferruginea
of a similar size which had the front quite as much rounded off. Davidson [1868, p. 307] also
states that there can be no doubt as to the shell termed Lingulella unguiculus by Salter in 1865
being the same species as L. ferruginea described in 1867. He also states that it is true that
L. ferruginea, like most of its congeners, varies slightly in its shape in different examples; some
having their front and middle more rounded than others, and the posterior portion converging
rather more in some individuals than in others. :

Davidson [1871, p. 336] further observes that—
this small species has been correctly described and illustrated by Mr. Salter; and is, as far as we are aware, the earliest
brachiopod hitherto discovered; for specimens [Davidson, 1871, Pl. X LIX, fig. 35] were found by Hicks at the middle
and the very base of the purple and red rocks of Sedgwick’s “‘Harlech group,’’ which directly underlies the ‘“‘Menevian
group” or lowest Lingula flags. The position is about 1,200 feet (365.8 m.) lower in the series than the specimen

described by Salter and Hicks [1867, p. 340]. The shell does not appear to be scarce, but the beds are much cleaved,
and their color is not in any way favorable to the exhibition of the characters of so thin a shell.

In my remarks [1884a, p. 15] upon the species “ Lingula ? dawsoni”’ Matthew, I called atten-
tion to the close resemblance between that species and Lingulella ferruginea, and said that
with only a specimen of the ventral valve for comparison it was difficult satisfactorily to
determine the specific relations of the species.

With the large collections now before me from Newfoundland, and Matthew’s and our
own specimens from New Brunswick, it is possible to refer the form that has been described
as Lingula? dawsoni to Lingulella ferruginea.

Before making comparisons between the American and Welsh representatives of the
species described, I will quote the original description of L. dawsoni [Walcott, 1884a, p. 15],
and add such additional data as the specimens from the other collections of Newfoundland
have afforded:

Shell small, broadly subelliptical, subattenuate toward the beak; the margins gradually expanding and curving
from the beak to the center, where the shell has its greatest width, and thence narrowing toward the front, which is
broadly rounded. General surface depressed, convex, becoming more convex toward the beak.

Surface marked by fine undulating concentric lines crossed by radiating lines that are seen only by the aid of a
strong magnifying glass.

In form this species approaches Lingulella ferruginea Salter of the Menevian formation of Wales quite closely,
but with only a specimen of the ventral(?) valve to compare with it, it is difficult satisfactorily to determine its
specific relations.

From the Newfoundland material the following additional description is taken:

The dorsal valve is ovate and moderately convex as it occurs in the shale.

The shell appears to have been thin, and built up of two or more layers or lamelle. The
surface described for the type specimen is correct for the surface when the thin outer layer
is exfoliated. The outer surface, as shown by a small bit of it on the type specimen, is of the

62667°—vou 51, pr 1—12 32

498 CAMBRIAN BRACHIOPODA.

same general character as that of Lingulella radula Matthew and Lingulella mariinensis
Matthew. It is exceedingly fine and is discernible only with a strong magnifier.

The surface of a specimen represented by Plate L.XIX, figure 1t, is marked, in addition
to the radiating and concentric lines, by irregular, more or less transverse lines that suggest
the surface of species referred to the subgenus Westonia. Associated specimens do not show
this peculiarity of surface. _

The interior of the dorsal valve is not: well shown. In two specimens (Pl. XXIX, figs. 1
and 11) traces of the visceral area are preserved, and the area and pedicle groove are indicated
in figure 1f. In the casts of the dorsal valve the area is clearly defined (fig. In) and the trans-
median (i) and the central muscle scars (h) (fig. 1q). The main trunk of the vascular sinus
is far out toward the margins (fig. Ir), and in the same interior the paths of advance of the
muscle scars are unusually prominent. A median sinus appears to be indicated in figure In.

Observations—Through the courtesy of Dr. Gilbert D. Harris I have been able to com-
pare the type specimen of “ Lingula? dawsoni,’’ which belongs to the Hartt collection of Cornell
University, with the specimens referred to the species by Matthew. Only one of Matthew’s
specimens [1886, Pl. V, fig. 9d] belongs to the species. Two other specimens, however, described
and figured as ‘‘ Lingulella linguloides”’ [Matthew, 1886, p. 34], are undoubtedly specifically iden-
tical with the original type of “ Lingula? dawsoni,’”’ Matthew’s identification bemg based on the
ficure of the specimen described and illustrated by me [1884a, p. 15].

Two other specimens illustrated by Matthew [1886, Pl. V, figs. 9, 9a-c] as “‘ Lingulella
dawson” appear to be identical with L. martinensis Matthew. Both the ventral and dorsal
valves of the two figured specimens are broken away at the beak, and allowance is also made
for their being compressed in shale, while the types of L. martynensis are embedded in sandstone.

Tt will be noticed that our Plate X XIX, figure 1, differs from Matthew’s figure 9d [1886,
Pl. V] in the form of the visceral area, although they are drawn from the same specimen. The
shell is small, and the markings are somewhat indistinct, but from what may be seen and
from our knowledge of the form of the markings in the closely related species, I think the change
in the figure is necessary.

A shell that appears to be identical with this species occurs in the compact, gray, thin-
bedded sandstones that are interbedded in the Upper Cambrian shales on McNeil Brook,
1.5 miles (0.94 km.) east of Marion Bridge, Cape Breton, Nova Scotia. The species is abun-
dantly represented, the partings of the shaly sandstone often being nearly covered with the
detached valves. The average length of the ventral valve is 3 mm.

Lingulella ferruginea occurs in abundance in the shales and interbedded limestones of the
Manuels Brook section, Newfoundland, and also in the dark shales above the Lower Cambrian
beds near Topsail Head, on the shore of Conception Bay. In order to exhibit the range of
variation caused by the character of the embedding matrix, a number of specimens are illus-
trated. Plate X-XIX, figures le to 1k, and In, are from the shales; figures 1f, 11, 1j, and 1k
show the effect of compression and distortion, while figures 11, 1m, lo, 1p, and 1q, from the
limestone, are more convex and regular, although the specimens they represent were chosen
as illustrating variation in form.

In the Manuels Brook section, Newfoundland, Lingulella ferruginea is associated with
Acrotreta misera, Agnostus punctuosus, Microdiscus punctatus, Paradoxides davidis, P. hicksi,
Anopolenus venustus, Conocoryphe elegans, Ctenocephalus mattheur, Erinnys venulosa, Ptycho-
paria robbi, P. variolaris, Holocephalina inflata, Agraulos socialis, etc. [Walcott, 1891b, p. 261].

Davidson [1868, p. 306] gives a list of the fossils that occur in association with Lingulella
ferruginea in the Menevian group of Wales. Among them we find Paradozxides davidis, P.
hicksi, Erinnys venulosa, Ptychoparia variolaris; also the genera Holocephalina and Anopolenus.

The above-mentioned association of species in the Newfoundland and Welsh beds shows
that Lingulella ferruginea occurs in the same relative faunal horizon on the two sides of the
Atlantic. A comparison of the illustrations of the type specimens [Salter and Hicks, 1867,
figs. 1-3] and those subsequently described and illustrated by Davidson [1871, Pl. XLIX, figs.
33 and 35] shows clearly that there are no true specific differences between the two species.

OBOLIDA. 499

In order to place these clearly before students, the original figures of Salter [Salter and Hicks,
1867, figs. 1-3] and Davidson [1871, Pl. XLIX, figs. 33 and 35] are reproduced on Plate XXIX.

“Teptobolus gemmulus” Matthew [1903, p. 190] appears to be a true Lingulella and specific-
ally identical with L. ferruginea. It occurs at a higher horizon (Division 3¢ of Matthew’s sec-
tion) than the typical forms of the latter in Wales and near St. John, New Brunswick, but
that is not surprising for a species which has so wide a geographic distribution. Only one
specimen from the type locality at Navy Island, St. John, sent to me by Matthew, shows the
area and central groove of the ventral valve. In tho shales of his Division C3e on McLeod
Brook, Cape Breton, Matthew collected a fine series of compressed and flattened shells that
he referred to ‘‘Leptobolus gemmulus.”’ These shells appear to have the broad form as the
result of being flattened in the shale. The same changes occur in typical specimens of L. ferru-
ginea when flattened in the shales at Andrarum, Sweden. In the interbedded limestones they
are narrower and more convex. I note the same differences also in specimens from the shaly
sandstones of McNeil Brook, Cape Breton. The narrow, uncompressed forms are shown by
Plate XXXV, figures 4, 4a-b. In the same sandy shales occur.flattened shells that are as
broad as those referred to ‘‘Leptobolus gemmulus” Matthew [1903, p. 190] (Pl. XXIX, figs.
lu and iv).

Lingulella lepis Salter, when uncompressed, has the broad form given to L. ferruginea
by compression, and would be compared with Matthew’s “Leptobolus gemmulus” if the latter
were retained as a species.

A species that appears to be identical with this occurs at Hastings Cove, St. John County,
New Brunswick, and a closely allied form, compared by Matthew [1895a, p. 115] with Lingulella
granvillensis, occurs in the “Protolenus beds” of Hanford Brook, St. John County, New
Brunswick.

Linnarsson [1876, Pl. III] gives several illustrations of a small Lingulella from the Para-
doxides beds. One of them (see Pl. XXXI, fig. 3c) is an elongate form that may represent a
distinct species from the broader forms represented by Plate X-X-XI, figures 3, 3a, and 3b in
this monograph. A direct comparison between specimens from the limestones of Sweden
and Newfoundland leads to the conclusion that they belong to the same species.

Kayser [1897, Pl. VII, fig. 7] illustrates a species of Lingulella from ITruya, northern
Argentina, that he compares with L. ferruginea Salter. It certainly resembles that species
very closely, and with our present knowledge of the wide distribution of L. ferruginea, I believe
we are justified in identifying the South American form as the representative of that species.
The figure given by Kayser [1897, Pl. VII, fig. 7] is reproduced on Plate XXX. The associated
species given by Kayser [1897, pp. 277-281] are Liostracus ulrichi, L. steenmanni, L. sp., Agnostus
druyensis, Lingulella cf. davisi, and Orthis saltensis.

ForMATION AND LOCALITY.2—Upper Cambrian: (3h) Shale and shaly limestone on McNeil Brook, 1.5 miles (2.4
km.) east of Marion Bridge; (307 [Matthew, 1903, p. 192]) shales of Division C3c of Matthew, on McLeod Brook (=Bara-
chois River); and (307a [Matthew, 1903, p. 240]) shales of Division C3c2 of Matthew, on McLeod Brook (=Barachois
River), near Boisdale; all in eastern Cape Breton, Nova Scotia, Canada.

(308 [Matthew, 1892, p. 41]) Shales of Division C3c of Matthew at Navy Island, St. John Harbor, St. John County,
New Brunswick, Canada.

(8) Shaly limestones 300 feet (91.4 m.) above the Paradorides zone, Manuels Brook, Conception Bay, Newfound-
land.

(310d) Ceratopyge slate at Borgholm, Oeland Island, Sweden.

(389d [ Kayser, 1897, p. 280]) Iruya, Province of Salta, Argentina, South America.

Middle Cambrian: (3i) Compact, fine-grained, thin-bedded, gray sandstone of the Paradoxides zone, on McLean
Brook, 1 mile (1.6 km.) east of McCodrum Brook, and 1.5 miles (2.4 km.) west of Marion Bridge, eastern Cape Breton,
Nova Scotia, Canada.

(2s) Limestone in upper part of Paradoxides zone, at Hastings Cove [Matthew, 1898b, p. 38], on Kennebecasis
Bay, 0.5 mile (0.8 km.) northeast of Torryburn, on the Intercolonial Railway northeast of St. John; (2i) sandstones
of Division 1b3 of Matthew’s [1895a, p. 108] Protolenus zone, on Hanford Brook; and (21) limestone at the base of
the Paradoxides zone [Matthew, 1895a, p. 108]; all on Hanford Brook, St. John County, New Brunswick.

(3011) Shales of Division 1d of Matthew on Porters Brook, St. Martins; (2m) shales near the base of the Paradomides
zone on Hanford Brook; (301k) St. John formation in the city of St. John; (301h) shales of Division 1c of Matthew,
on Hanford Brook; (301g) sandstones of Division 1c of Matthew, at Portland (now a part of the city of St. John); and

a This species also occurs at Localities 318u and 318v, p. 249.

500 CAMBRIAN BRACHIOPODA.

(301z) in Division le of Matthew at Ratcliffs Millstream; all [Matthew, 1886, p. 34] in St. John County, New
Brunswick.

(1a, 61, and 6n) Shales near the top of No. 6 of the Manuels Brook section; (6r and 6) limestone and shale, respec-
tively, on the west side of Manuels Brook; (1) shales of zone A of No. 7 of the Manuels Brook section; and (2) shales
of zone B of No. 7 of the Manuels Brook section; all on Manuels Brook [Walcott, 1891b, p. 261], Conception Bay,
Newfoundland.

(2a) Shales from same horizon as No. 1, Topsail Head, Conception Bay, Newfoundland.

(6g) Limestone near the base of the Middle Cambrian, the lowest horizon carrying Paradowides, northwest side
of Chapple Arm Harbor, about 1 mile (1.6 km.) from its head, Trinity Bay, Newfoundland.

(318j [Salter, 18666, p. 340]) Black shales of the Menevian group at Pen-y-pleidiau, St. Davids; (318h) shales in the
Menevian at St. Davids; (3180) @red shales at the base of the Harlech grits at Solva; (866b) red shales at the base of the
Harlech grits at Blowdnglne Harbor, south of St. Davids; and (318n) 4 red shales at the base of the Harlech grits at St.
Davids; all in South Wales.

(18e) Lower portion of the Meneyian at Camlan; (318k)¢ in the Menevian rocks at Tafern Heli; (318 a4 in
the Menevian rocks at the Waterfall Valley, near Maentwrog; all in North Wales.

(8w) Limestones of the Paradoxides forchhammeri zone, at Andrarum, 20 miles (32.2 km.) northwest of Simri-
shamn, Province of Christianstad; (310q) limestone of the Agnostus lxvigatus zone at Lovened, Province of Skaraborg;
(320m [Linnarsson, 1876, p. 15]) limestones of the Paradoxides forchhammeri zone at Kinnekulle, Province of Skaraborg;
(320n [Linnarsson, 1876, p. 16]) limestones of the Paradoxides forchhammeri zone at Lovened, Djupadal, 19 miles (30.6
km.) south-southeast of Skara, Province of Skaraborg; (310m [Linnarsson, 1876, p. 16]) arenaceous shales of the Para-
douides tessini zone on Oeland Island; (3100) limestone of the Paradovides tessini zone at Borgholm, Oeland Island;
(3810p) limestone of the Paradowides elandicus zone at Borgholm, Oeland Island; (310y) limestone at Kiviks Esperéd,
Province of Malméhus; and (310z) limestone at Brantevik, on the shore a little south of Simrishamn, Province of
Christianstad; all in Sweden.

(16h) Limestones of the Paradoxides forchhammeri zone at Borregaard; and (16j) limestones of the Paradowides
forchhammert zone at Laesai; both on Bornholm Island, Denmark.

(324d) Windjuelandet, Ringsaker, Province of Hedemarken, Norway.

This species is somewhat doubtfully identified from the following localities:

Upper Cambrian: (6s) Just north of Fosters Point, Random Island, Random Sound, Newfoundland.
Middle Cambrian: (i) Shales of zone A of No. 7 of the Manuels Brook section [Walcott, 1891b, p. 261], Manuels
Brook, a small stream which flows into Conception Bay from the east, near Topsail Head, Newfoundland.
(2i) Sandstones of Division 1b3 of baile s [1895a, p. 108] hohellanns zone, Hantord Brook, St. John County,
New Brunswick.
LINGULELLA cf. FERRUGINEA.

Plate XXX, figure 4.

Lingulella (?) sp. Pomprcss, 1896, Jahrb. K.-k. geol. Reichsanstalt, Bd. 45, Hft. 3, p. 509, Pl. XIV; figs. 16a—b.
(Described in German; see below for translation. Figs. 16a—b are reproduced in this monograph, Pl. XXX,
fig. 4.)

The original description by Pompeckj is as follows:

There is on hand a ventral valve which, owing to its bad state of preservation, can not be assigned to the genus
Lingulella otherwise than doubtfully.

Outline elongated, pentagonal with corners rounded off. The length issomewhat more than double the breadth.
The vertex (beak?) is drawn far forward. The surface shows a concentric striation. In front of the vertex (beak?)
is seen a short median groove.

The form recalls Lingulella (?) sp. undt., which Linnarsson [1876, p. 15] described from Kinnekulle; but it is
more slender than the species made known from the Paradowides slate of Sweden.

This little shell is probably the representative of Lingulella ferruginea Salter of the English
and Swedish Paradoxides fauna.

FORMATION AND LOCALITY,—Middle Cambrian: (345 [Pompeckj, 1896b, p. 509]) Greenish shales in the
Paradoxides zone on the Dlouhd4 Hora, above the brook of Sbirov, near Skrej, Bohemia, Austria-Hungary.

LINGULELLA FLUMENIS (Matthew).
Plate XX XY, figures 6, 6a—b.

Leptobolus flumenis Marraew, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, pp. 189-190, Pl.
XI, figs. 7a-f. (Described and discussed as a new species; see p. 501 for copy. The specimens represented
by figs. 7a, 7b, and 7e are redrawn in this monograph, Pl. XX XV, figs. 6, 6a—b, respectively.) ‘

a Davidson, 1871, p. 337.

OBOLIDA. d01

The original description by Matthew is as follows:

A narrowly ovate species, somewhat straight on the sides, and broadly rounded in front.

The ventral valve has an obtusely pointed beak, bent down at the apex. Sides of the valve somewhat sharply

sloped in the posterior half and gently sloped in front. Interior.—This shows an area nearly half a millimeter long,
and a visceral callus extending about half the length of the valve. The lateral ridges within the valve extend as far;
and in front of them, reaching to within a sixth of the length of the valve from the front, isa pair of arched vascular
grooves not far from the margin of the valve; numerous external branches from these trunk grooves extend to the
flattened margin of the valve. The individual length of these branches is about equal to the width of the main
groove. :
The dorsal valve is obtusely rounded at the hinge area, which is very short, and here and at the sides the valve
is strongly arched downward, but is gently sloped down in front. Jnterior.—In front of the linear cardinal area is a
pair of pits marking the insertion of the cardinal muscles. The middle of the valve for more than half the valve’s
length has a flattened band marking the progress of the central muscles during the growth of the shell. At the front
this band is about one-sixth or one-eighth of the width of the valve, and at its sides are faint prints of the central
muscles; and at the front are two pairs of minute pits, one or both of which marks the position of the anterior laterals.
The place of the posterior laterals is marked by a series of small pits near the margins in the posterior third of the valve.
In front of these pits are the strong arched grooves left by the vascular trunks, which extend across the middle half
of the valve near its margins. ;

No examples have been obtained showing the surface markings, except those near the front of the valve; but
both valves show from four to six ridges of growth in the anterior quarter of the valve. These ridges are broadly
curved in the middle part, but more abruptly at the sides.

Ventral valve 4 mm. long and 2.5 mm. wide. The dorsal valve is nearly one-half millimeter shorter than the
ventral.

This species is of nearly the same size as L. insulx, but is less elliptical in outline, and the valves are more flat-
tened in front; the area of the ventral valve also is longer, and that of the dorsal shorter than in that species; also the
central group of muscles is not set so far forward as in that of the dorsal of the species cited.

This species differs from ZL. atavus of the Etcheminian terrane in having the central muscles of both valves set
farther back.

The exact horizon of this species is uncertain, as the outcrop is in an isolated basin [Mat-
thew, 1903, p. 51]. Matthew correlated it with his section on the lithologie character of the
matrix. The form is very much like that of Lingulella collicia (Matthew), and it appears to
be identical with small shells of the latter species.

ForMATION AND LOcALITY.—Middle Cambrian: (325a [Matthew, 1903, p. 190]) Shales of Division C2c of Mat-

thew’s [1903, p. 49] Bretonian on the eastern slope of the valley of McNeil Brook, on the road to Trout Brook, in the
Mira River valley, eastern Cape Breton, Nova Scotia.

LINGULELLA FRANKLINENSIS (Walcott).
Plate XXVI, figures 3, 3a-b.

Obolus (Lingulella) franklinensis Watcorr, 1898, Proc. U. S. Nat. Mus., vol. 21, pp. 404-405. (Described and dis-
cussed essentially as below as a new species.)

Shell small, ovate, moderately convex, with the apex of the dorsal valve subacuminate.
Surface of the shell marked by rather strong lines and striw of growth, with very fine, slightly
irregular, wavy striz between the coarser concentric striz. Two ventral valves referred to
this species have a length of 3 and 3.5 mm., respectively, with a width of about 2.75 mm.
There are no dorsal valves in the collection. A partial cast of the interior of the shell carries
an impression of radiating striz, a strong cast of a narrow pedicle furrow, and a few concentric
lines of growth. If the shell represented by Plate XXVI, figure 3b, belongs to this species,
the interior surface was also marked by scattered bits of puncte.

Observations.—This species is founded on three specimens of the ventral valve that occur
in the limestones interbedded in dark shales above the Lower Cambrian Olenellus-bearing
shales. A larger shell (Pl. X XVI, fig. 3b) has the same surface characters and occurs at the
same relative geological horizon, and it may belong to this species; the only specimen of it
in the collection is apparently a dorsal valve. The exact stratigraphic horizon has not been
determined, but from the associated species of Agnostus and Ptychoparia it appears that the
reference should be to the Middle Cambrian.

502 CAMBRIAN BRACHIOPODA.

The material for study is so limited that it is difficult to make comparisons with other
species. In form the ventral valve resembles that of Lingulella lineolata (Walcott) (PI. XLVIII),
L. tarpa (Walcott) (Pl. XXIII), and in some respects L. granvillensis Walcott (Pl. XXII), with
which it would be more naturally compared owing to its belonging to the Appalachian fauna.

The specific name is derived from Franklin County, Vermont, in which the species occurs.

ForRMATION AND LOCALITY.—Middle Cambrian: (28a) “‘St. Albans formation,’’ in limestone lentil about 1 mile
(1.6 km.) east of Parker’s quarry, west of Georgia; (319v) sandy shale, 2 miles (3.2 km.) east of Highgate Springs; and
(87) conglomerate limestone 1 mile (1.6 km.) south-southwest of Highgate Falls; all in Franklin County, Vermont.
LINGULELLA FUCHSI Redlich.

J

We?
Plate XX XIX, figures 2, 2a-c, 3

Lingulella fuchsi RepuicH, 1899, Mem. Geol. Survey India, Paleontologia Indica, new ser., vol. 1, No. 1, Cambrian
Fauna of the Eastern Salt Range, p. 7, Pl. I, figs. 10a-e. (Described and discussed as a new species. ~ Fig. 10c
is reproduced in this monograph, Pl. XX XIX, fig. 3.)

Obolus (Lingulella) fuchsi (Redlich), Watcorr, 1905, Proc. U.S. Nat. Mus., vol. 28, p. 332. (Discussed somewhat as
below.)

In the collection of fossils received from Doctor Noetling I find, associated with Lingulella
wanniecki Redlich, a small elongate form that appears to be identical with L. fuchst of Redlich.

Redlich states [1899, p. 10] that his LZ. fuchsi occurs in a hard clay above the lower magnesian —

sandstones which rest on the shales containing L. wanniecki. If my identification of the species
is correct, L. wanniecki has a greater vertical range, or there may have been some error in the
identification and labeling of the zone from which the original specimens were obtained. The
identification of the species in the material before me is based on the form of the ventral valve, as
shown by Redlich’s figure 10c [1899, Pl. I] and my figure 2 (Pl. XX XIX). The dorsal valves
represented by Plate XX XIX, figures 2a-c, differ materially from Redlich’s illustration; but in
the specimen represented by figure 2d the little pit mentioned by Redlich [1899, p. 7] is shown,
also two ridges that leave a concave furrow in the central portion of the cast of the valve.
These are the lines of the main vascular sinuses.

ForMATION AND LOCALITY.—Middle Cambrian: (15r)@ Dark argillaceous shale, at Khussak, Salt Range, India.
LINGULELLA GRANDIS (Matthew).

Plate XX XVIII, figures 2, 2a-f.

Leptobolus grandis MartuEw, 1894, Trans. Roy. Soc. Canada for 1894, Ist ser., vol. 11, sec. 4, No. 8, pp. 91-92, Pl.
XVI, figs. 7a-c. (Described and discussed as a new species. The specimens represented by figs. 7a and 7b are
redrawn in this monograph, Pl. XX XVIII, figs. 2b and 2f, respectively.)

Lingulella? cuneata MartHEw, 1894, idem, pp. 92-93, Pl. XVI, Age. 5a-b. (Described and discussed as a new species.
Matthew’s types of Lingulella cuneata are figured in ‘ag monograph, Pl. XX XVIII, figs. 2, 2a, 2c, and 2d, but
it is impossible to tell which of these Matthew figured, Pl. XVI, figs. 5a-b.)

Lingula cf. billingsiana Whiteaves, MartHew, 1894, idem, p. 93, Pl. XVI, figs. 6a-b. (Described and discussed.)

Lingulella 2 billingsana ScuucHeERt (in part) [not (WurrEaves)], 1897, Bull. U.S. Geol. Survey No. 87, p. 256. (Merely
changes generic reference of Matthew’s species Lingula ctf. billingsiana cited above.)

Not Leptobolus cf. grandis Matruew, 1902, Trans. Roy. Soc. Canada for 1902, 2d ser., vol. 8, sec. 4, No. 3, p. 111.
(Characterized. This species is given by Matthew as occurring on Mount Sigghen, Bere Chimp. For the
species occurring at this locality see pp. 127-128.)

General form subcuneate, with the ventral valve acuminate and the dorsal valve elongate-
ovate; valves more than usually convex for a species of the genus. Surface of shell marked by
concentric striz and strong lines of growth, and, where the outer surface is perfect, by almost
microscopic, irregular, semi-inosculating, elevated striz, that under a high power give the surface
an appearance somewhat similar to that of Lingulella (Lingulepis) roberti (Matthew) and
Obolus ( Westonia) ella (Hall and Whitfield) (Pl. XLVII). In almost every instance this surface
adheres to the matrix, leaving the glossy inner surface described by Matthew [1894, p. 92]; the
inner layers or lamelle are marked by numerous fine radiating striz and concentric growth lines;

aSpecimens from the type locality were given to the United States National Museum and this number was assigned to them.

OBOLIDZ. 503

a few large puncte were seen on the interior of one ventral valve. The shell is unusually thick
for its size. It has a thin outer layer and several inner layers or lamelle that are arranged very
much as in Lingulella acutangula (Roemer) (Pl. XVII).

A relatively large ventral valve has a length of 7 mm. and a width of about 5.5 mm.

The cast of the area of the ventral valve shows a long area divided midway by a narrow
pedicle groove, and toward the lateral margins by a very narrow flexure line. The area of the
dorsal valve is shorter in proportion than that of the ventral valve, and also less extended on
the cardinal slopes. ‘The cast of the visceral cavity (v), mcluding the outline of the heart-shaped
cavity (x), is very well shown by Plate XX XVIII, figures 2a and 2b. There are no traces of a
median septum in the ventral valve, but in the dorsal valve it is a very narrow sharp crest on
the summit of the broad, strong, median ridge that extends from the area fully three-fourths of ~
the distance to the front margin; the septum appears to be confined to the anterior half of the
length of the ridge.

The muscle scars are not clearly defined in either valve. The trapezoidal areas of the
ventral valve, where the central scars and the middle and outside laterals are usually located,
are present, but the individual scars can not be differentiated. In the dorsal valve the central
scars appear to be unusually large; they are situated on each side of the broad median ridge, and
crowd the parietal scar out to the main vascular sinus; the anterior laterals are situated on each
side of the median septum, as shown in Plate XX XVIII, figure 2d, but they are not well defined.

. The main vascular sinuses of the ventral valve extend far forward and curve inward so
that they appear nearly to unite a short distance back of the anterior margin of the shell; their
interior lateral branches appear to touch, and thus give the appearance of uniting the two main
sinuses; the lateral branches extend outward from the main sinus nearly to the edge of the shell,
while the interior lateral branches are crowded into the space between the main vascular sinuses
and the visceral area. The main vascular sinuses of the dorsal valve extend well forward and
curve inward toward the median line; their interior lateral branches fill the narrow space between
the vascular cavity and the main sinuses; no traces have been observed of the peripheral
branches of the vascular system of the dorsal valve. The parietal scar is shown more clearly
for the dorsal than for the ventral valve. In the former it extends about the space occupied by
the central scars, but it has not been traced outside of the main sinuses or in front of the
anterior lateral muscle scars.

Observations.—I was greatly puzzled when studying Matthew’s figures [1894, Pl. XVI] of
“Leptobolus grandis, Lingulella? cuneata, and Lingula ct. billingsiana.” It seemed, after
extended study of the character and variation of the interior markings of Obolus and Lingulella,
that the three species should be referred to Lingulella and perhaps to one species. Doctor
Matthew very kindly sent me his material, including the type specimens of this species. At
first I was inclined to consider ‘‘Leptobolus grandis” as distinct from Lingulella, but on close
study it became more and more evident that the differences were such that a generic distinction
could not be based upon them. The anterior extension of the main vascular sinuses varies
both in form and degree with different species of Lingulella. This may be seen by comparing
Lingulella ampla (Owen), Lingulella acutangula (Roemer), etc. The position and size of the
visceral area and muscle scars of the dorsal valve are also subject to great variation, as may be
seen by comparing Lingulella acutangula, and L. ampla.

All of the material of Matthew’s “Leptobolus grandis, Lingulella ? cuneata, and Lingula cf.
billingsiana” is from one locality and bed. It comprises a large number of shells on some
twenty-seven pieces of rock. I found that there was more or less distortion of the shells by
both vertical and lateral compression. Where the interior markings are well preserved the
shells can be at once referred to Lingulella grandis. It is only in shells that are distorted or a
little larger, or where the interior is imperfectly shown, that any doubt arises, and even in this
case no undoubted dorsal valve was found that could be referred. to any other species than
L. grandis.

The illustrations of “Lingulella? cuneata”’ [figs. 5a and 5b] and “Lingula cf. billingsiana”’
[figs. 6a and 6b] by Matthew [1894, Pl. XVI] are all of ventral valves, and the figures of “‘ Leptobolus

504 CAMBRIAN BRACHIOPODA.

grandis” [figs. 7a and 7b] are so diagrammatic that it is impossible to make comparisons between
them and the drawings of the same specimens which accompany this monograph.

FoRMATION AND LOCALITY.—Lower Ordovician: (301s) Gray sandstones of Division 3e(?) of Matthew [1894, p. 91] at
McAphee’s corner, Hardingville, St. John County, New Brunswick.

LINGULELLA GRANVILLENSIS Walcott.

Plate XXII, figures 1, la-d.

Lingulella granvillensis Waucorr, 1887, Am. Jour. Sci., 3d ser., vol. 34, pp. 188-189, Pl. I, figs. 15, 15a-c. (Described
and discussed as a new species. The specimens represented by figs. 15, 15a, and 15b are redrawn in this mono-
graph, Pl. XXII, figs. le, 1d, and 1, respectively.)

* Lingulella granvillensis Walcott, OEHLERT, 1889, Annuaire géologique universel for 1888, tome 5, p.1138. (Described in
French in a review of the anmating reference.)

Lingulella granvillensis WaLcott, 1891, Tenth Ann. Rept. U. S. Geol. Survey, pp. 607-608, Pl. LXVII, figs. 4, 4a-d.
(Description and figs. 4, 4a—c, anpied from Walcott, 1887, p. 188, Pl. I, figs. 15, 15a-c.) :

Lingulella granvillensis Walcott, Hau and CuarKE, 1892, Nat. Hist. New Yanik, Esleamielinny vol. 8, pt. 1, p. 58.
(Discussed.)

General form rather broadly ovate, with the ventral valve obtusely acuminate and the
dorsal valve obtusely oval. Valves moderately convex, the dorsal bemg somewhat more so
than the ventral. Surface of shell marked by concentric lines of growth, with very fine, slightly
undulating strize between them, and a few very indistinct radiating strie. The character of
the surface of the inner layers and of the interior of the shell is unknown. The shell appears
to have been rather thin and formed of a thin outer layer and one or more inner layers or
lamelle.

A rather large ventral valve has a length of 6 mm. and a width of 4.5,.mm., and an asso-
ciated dorsal valve 5 mm. in length has a width of 3.5 mm. The interior of a small ventral
valve shows the visceral area and the two main vascular sinuses; on a cast of the dorsal valve
the main vascular sinuses are shown, also a fine irregular network of mterior branches of the
main sinuses and a few peripheral branches of the vascular system. These are shown by
Plate XXII, figure 1d. A broad, low ridge, represented on the cast by a shallow depression,
extends forward in front of the area two-thirds the distance toward the frontal margin. It
is marked on the median line near the center of the shell by a sharp, narrow median septum,
and lines indicating the path of advance of the central and anterior lateral muscle scars. The
scars are not clearly defined, but appear to be situated as indicated on figure 1d. In front
of the anterior lateral muscle scars there is a peculiar rhomboidal area that is not so well defined
in any other species.

Observations.—This is one of the small species that in size and general form resembles
LTingulella ferruginea Salter of the Middle Cambrian of the Atlantic basin; also L. manticula
(White) of the Upper Cambrian and Lower Ordovician of the Rocky Mountain region; it
differs from the former in its broader anterior outline and from the latter in its more acuminate
form and shorter area.

This form owes its specific name to the occurrence of the type specimen near Granville,
New York.

ForMATION AND LOCALITY.—Lower Cambrian: (20a) Gray limestone, interbedded with shaly slates, in a lane
west of Lafayette Stevens’s house, about 100 yards (91.4 m.) from the main road, in the southern part of Whitehall
Township, Fort Ann quadrangle (U. S. Geol. Survey); (21a) limestone below the first fall of Mettawee River,
above the North Granville bridge, Fort Ann quadrangle (U. 8. Geol. Survey); (87b) limestones 0.25 mile (0.4
km.) east of Salem, Cambridge quadrangle (U. S. Geol. Survey); (38a) limestone 2 miles (3.2 km.) south of North
Granville, on the first road which turns south from the road running between that village and Truthville, 4 miles (6.4 km.)
west-northwest of Granville, Fort Ann quadrangle (U. S. Geol. Survey); (34) limestone on roadside a little west
of the bridge over Poultney River, at Low Hampton, about 5 miles (8 km.) east-northeast of Whitehall, Whitehall
quadrangle (U. S. Geol. Survey); (388m) limestone on the roadside north of schoolhouse No. 4, in the northeast
part of Whitehall, Whitehall quadrangle (U. S. Geol. Survey); (35) limestone 1.5 miles (2.4 km.) north of Bald
Mountain, and 3.5 miles (5.6 km.) north-northwest of Greenwich, Schuylerville quadrangle (U. S. Geol. Survey);

(38) limestone 0.25 mile (0.4 km.) north of John Hulett’s farmhouse about 3 miles (4.8 km.) west of South Granville,
and 4.5 milés (7.2 km.) southwest of Granville, Fort Ann quadrangle (U. S. Geol. Survey); and (8381) limestone in

OBOLIDZ. 505

the northern part of Easton Station, 3 miles (4.8 km.) south of Greenwich, Cambridge quadrangle (U.S. Geol. Survey);
all in Washington County, New York.

(29) Limestone just above the bridge at the Stockport paper mill, on Kinderhook Oreek; and (44b) limestone
near North Chatham in the northern part of the Kinderhook quadrangle (U.S. Geol. Survey); both in Columbia
County, New York. 2

(25a) Limestone on the Hall (Donaldson’s) farm, 2 miles (3.2 km.) east of Swanton, Franklin County, Vermont.

LINGULELLA HAYESI (Walcott).
Plate XXV, figures 1, la-j.

Obolus (Lingulella) hayesi Waucorr, 1898, Proc. U. S. Nat. Mus., vol. 21, pp. 405-406. (Described and discussed
as a new species, essentially as below.)

Shell small; general form broad ovate, with the ventral valve obtusely acuminate and the
dorsal valve rounded ovate; valves moderately convex. Outer surface as seen in casts marked
by fine, concentric lines and striz of growth; the inner surface had fine, radiating striz and
scattered pits or puncte. The shell appears from the casts to have been of medium thickness
and built up of several layers or lamelle. 4

The average length of the ventral valve is about 3.5 mm.; width about 3mm. The dorsal
valves are a little shorter than the ventral valves, the length and width being about the same,
although some of the shells are a little wider than long.

The casts of the interior of the ventral valve show a clearly defined, strong area, divided
midway by the cast of a narrow pedicle groove, and again by sharp flexure lines situated a
little nearer the pedicle groove than to the lateral margins. The striz of growth cross the
area parallel with its base, arching over the cast of the pedicle furrow. The area formed a
thin shelf between the pedicle groove and the lateral margins, the undercut extending back
under the area as shown in the cast by a thin projection of the embedding rock over the area.
The area of the dorsal valve is of medium length and marked by strie of growth and rather
clearly defined flexure lines.

The cast of a ventral valve shows the visceral cavity and rather strong and long main
vascular sinuses. In the dorsal valve the main vascular sinuses are frequently outlined very
beautifully on the siliceous casts; the visceral area surrounded by the parietal band is clearly
defined, also the central and anterior lateral muscle scars, and in one cast the transmedian
muscle scars.

Observations —This very pretty species occurs quite abundantly on the siliceous nodules
embedded in the Conasauga (‘‘Coosa’’) shale. It resembles in form Obdolus lamborni (Meek)
and Obolus willisi (Walcott), but is a much smaller species. The elongate visceral cavity of
the dorsal valve is also of the same type as that of those species. The thickening in front
of the visceral cavity (Pl. XXV, fig. 1b) is similar to that which occurs in Obolus matinalis
(Hall) (Pl. V, fig. 1d). In this character and in its broadly ovate form it comes very close
to the forms which are referred to Obolus.

The specific name was given in honor of Dr. C. W. Hayes, at that time chief geologist of the
United States Geological Survey.

FoRMATION AND LOCALITY.—Middle Cambrian: (90x and 94a)@ In and attached to the outer surface of siliceous
aodules in the Conasauga (‘‘Coosa’’) shale, Coosa Valley, east of Center, Cherokee County, Alabama.

LINGULELLA HEBERTI Barrois.
sf Plate XX XIX, figures 11, lla-c.

Lnngulella heberti Barrots, 1882, Mém. Soc. géol. du Nord, vol. 2, pp. 185-186, Pl. IV, figs. 3a-d. (Described and
discussed in French as a new species; see below for translation. Figs. 3a-d are reproduced in this monograph,
Pl. XX XIX, figs. 11, lla-c, respectively.)

The original description by Barrois follows:

Shell corneous, regular, elongated, slightly convex, scarcely inequivalve. Enlarged in the pallial recion where
the outline is rounded; pointed at the beaks; longer than wide. Marked with well-developed concentric lines of

a 90x is the type locality.

506 CAMBRIAN BRACHIOPODA.

growth, some of which are stronger than others. The shell is covered with small fine tubercles, in lines, like certain
species of Kingena from the Cretaceous, and produced by the fine, oblique, granular striz. (Pl. XXXIX, fig. llc.)¢

The internal molds (Pl. XX XIX, fig. 11b)¢ show clearly that the beaks were provided with a strong pedicle
furrow much like that of Lingulella davisi, to which these shells have considerable resemblance. The median septum
is well marked, likewise the depressions corresponding to the point of attachment of the muscles of the pedicle (PI.
XXXIX, fig. 11b),¢ and also the transmedian muscles.

Observations: The Lingulella heberti is clearly related to Lingula attenuata Sowerby from the Llandeilo flags.
It is distinguished by the ornamentation of the shell, which recalls that of Zingulella granulata (Phillips). It should
also be compared with the form figured by Linnarsson [1876, Pl. III, figs. 24-30] under the name of Lingulella ?
nathorsti, from the Paradoxides forchhammeri beds of Sweden. The latter is perhaps a little longer, but has a very
great resemblance to our shell. Mr. Davidson, who has kindly communicated to me the results of his examination of
this small shell, so abundant at the base of the Silurian sandstones of Cape Vidio, agrees with us in referring it to the
genus Lingulella; he believes that despite its resemblance to Lingulella davisi and L. granulata, it would probably
rank as a new species. It is dedicated to M. Hebert, to whom we owe so many discoveries in Pyrenean geology.

Dimensions: Length, 8 to 10 mm.; breadth, 7 to 9 mm.

FoRMATION AND LOCALITY.—Ordovician: (350a) Sandstones of the stage of Cabo Busto, in the cliffs of Cape Vidio,
Province of Oviedo; and (350b) sandstones of the stage of Cabo Busto, at Los Negros; both [Barrois, 1882, p. 186] in
northeastern Spain.
LINGULELLA HELENA (Walcott).

Plate XXIV, figures 3, 3a-d.

Obolus (Lingulella) helena Waucort, 1898, Proc. U. S. Nat. Mus., vol. 21, p. 406. (Described and discussed essen-
tially as below as a new species.)

General form ovate, with the ventral valve obtusely acuminate, and the dorsal valve rounded
ovate. Valves moderately convex, as far as can be determined from their condition of preser-
vation in the shales. Surface of shell marked by rather strong lines of growth, and very fine
irregular, radiating, concentric striz that appear to inosculate, the surface having something
of the appearance of Obolus:(Westonia) ella (Hall and Whitfield). The character of the sur-
face markings of the inner layers and the interior of the shell is unknown. So far as can be
determined the shell is rather thin, and formed of a thin outer layer and one or more thin
inner layers or lamelle. A ventral valve 8 mm. in length has a width of 6 mm.; another 7.5
mim. in length has a width of 6 mm. An associated dorsal valve 7 mm. in length has a width
of 5mm. ‘These variations in outline are to a considerable extent due to distortion.

As shown in the cast of the interior of the shell, the area of the ventral valve is rather
long, and marked midway by a strongly defined cast of a pedicle groove, and midway between
that and the outer margin by a very distinct flexure line. The area of the dorsal valve is
rather long and quite distinctly marked on a cast of the interior. The cast of the interior of
the ventral valve shows a strong main vascular sinus (vs) on each side of the visceral area,
and in a cast of the dorsal valve a slight median septum is indicated, also traces of the main
vascular sinuses. The only traces of the muscle scars observed are the anterior laterals (j)
and a suggestion of the central scars in the dorsal valve.

Observations.—This species is associated with Obolus ( Westonia) ella (Hall and Whitfield)
in the siliceous shales near Helena, Montana, and what may be a similar form (Pl. XXIV, fig.
3d) occurs with the same species in Big Cottonwood Canyon, Utah, although the latter is quite

closely related to Obolus meconnelli (Walcott). In form and surface characters it belongs to —

the group of which Obolus (Westoma) ella may be taken as a type. It differs from O. (W.)
ella in being narrower anteriorly and in its more acute beak.
The specific name is derived from Helena, Montana, near which the type specimen was

collected.

FoRMATION AND LOCALITY.—Middle Cambrian: (30a) Shale on the north side of Big Cottonwood Canyon, 1 mile
(1.6 km.) below Argenta, Wasatch Range, southeast of Salt Lake City, Salt Lake County, Utah.

(64s) Dark blue-gray Langston limestone [Walcott, 1908f, p. 198], just above the Cambrian quartzitic sandstones,
north side of Twomile Canyon, near its mouth, 2 miles (3.2 km.) southeast of Malade, Oneida County, Idaho.

(4n) Limestone about 325 feet (99.1 m.) above the unconformable base of the Cambrian in divide at the head
of Jackson Creek (locally known as Sheep Creek), a creek flowing into Jackson Lake about 0.5 mile (0.8 km.) south
of its northwestern corner, Teton Mountains, Grand Teton quadrangle (U.S. Geol. Survey), Uinta County, Wyoming.

a Barrois’s figures are copied in this monograph, and these references are to the figures which correspond with those mentioned by him.

.

——

OBOLID. Or

(302s) Dark siliceo. s shale in a quarry in Last Chance Gulch, south slope of Mount Helena, 1.5 miles (2.4 km.) south
of Helena; and (4u) shales in the Gallatin formation of Peale [1893, Pl. IV], northwest side of canyon, 0.5 mile
(0.8 km.) south of Helena; both in Lewis and Clark County, Montana.

LINGULELLA ? HUMILLIMA (Barrande

i

LY
Plate XXX, figure 12.

Eingula humillima Barranve, 1868, Faune silurienne des environs de Hof, en Baviere, p. 101, fig. 70. (Character-

ized in French as a new species. Fig. 70 is reproduced in this monograph, Pl. XXX, fig. 12.)

Tingula humillina Barranpe, 1868, Neues Jahrb. fiir Mineralogie for 1868, p. 691, unnumbered plate, fig. 70.

(Copy of preceding reference.)

This species was described from a single small, oval, compressed shell. The author states
that its appearance does not permit its identification with any other described species. The
shell has a length of 5 mm.; width, 3.5 mm.

ForRMATION AND LOCALITY.—Passage beds between the Upper Cambrian and the Ordovician: (308¢ [Barrande,

1868a, p. 101]) Suburbs of Hof; and (303f [Pompeckj, 1896a, pp. 7 and 8]) railway cut near p Sielne len 3eng, alittle dis-
tance back of the railway station at Neuhof, near Hof; both in Bavaria, Germany.

LINGULELLA INO (Walcott).
Plate XXVI, figures 4, 4a-b.

Obolus (Lingulella) ino Waucort, 1898, Proc. U. 8. Nat. Mus., vol. 21, pp. 406-407. (Described and discussed essen-
tially as below as a new species.)

»

Shell a little smaller than the average of the species of the genus. General form ovate,
with the ventral valve subacuminate and the dorsal valve ovate in outline. There is some
range of variation in the outline of the valves, but as a whole they do not vary more than the
difference shown in the ventral valve by Plate XXVI, figures 4, 4a. The convexity of the
valves is fairly strong, as the shells are preserved in the somewhat shaly sandstones. Ventral
valves 7 mm. in length have a width of from 5.5 to 6 mm.; a dorsal valve 5 mm. in width has
a length of 5.25 mm. 4

As far as may be determined from the casts, the outer surface is marked by concentric
lines and striz of growth, and the inner surface by radiating strize and concentric lines of
growth and scattered pits or puncte. The shell appears to have been rather thick, and built
up of a thin outer layer and numerous lamelle that over the anterior two-thirds of the shell
were oblique to the outer layer; the edges of the lamellze show very plainly when the outer
layer is removed.

The area of the ventral valve as shown by casts of the interior is of medium length, divided
midway by a narrow elevated cast of the pedicle furrow, and again by a narrow flexure line
about halfway between the pedicle groove and the lateral margin; strize of growth cross it
parallel with the base. The area of the dorsal valve is relatively long, with the flexure lines
clearly defined. The interior markings shown in the cast of the ventral valve are the main
vascular sinuses and the outline of the visceral area; in the dorsal valve only traces of the
visceral area and main vascular sinuses have been observed.

Observations.—This species appears to be more nearly related to Lingulella tarpa (Walcott)
than to any other of the Middle Cambrian forms. It is a smaller shell than L. tarpa, and less
acuminate. It has the outline of some of the species of the Atlantic basin fauna such as
Lingulella radula Matthew (Pl. XLY), but it does not appear to be specifically identical
with any of them.

FORMATION AND LOCALITY.—Middle Cambrian: (18) Sandstones of the Rome formation, 1.5 miles (2.4 km.) east
of Post Oak Springs [Hayes, 1894, areal geology sheet], Roane County; (18b) sandstones of the Rome formation, north-
east of Rhea Springs | Hayes, 1894, areal geology sheet], Rhea County; and (11) sandstones and shales of the Rome
formation, about 1 mile (1.6 km.) east of Post Oak Springs [Hayes, 1894, areal geology sheet], Roane County; all in
Tennessee.

(18c) Sandstones of the Rome formation, west side of the sandstone ridge about 2.5 miles (4 km.) southwest of
Rome [Hayes, 1902, historical geology sheet], Floyd County, Georgia.

508 CAMBRIAN BRACHIOPODA.

LINGULELLA ? Insons (Barrande).
Plate XXXII, figures 2, 2a-e.

Lingula insons BARRANDE, 1879, Systéme silurien du centre de la Bohéme, vol.5, Pl. CV, figs. x: 1-6. (Not described,
but figured as a new species. Pl. CV, figs. x: 4A, 3A, 5A, 6A, 6H, and If are contadl in this monograph, Pl.
XXXII, figs. 2, 2a-e, respectively.)

This is one of the forms that, in the character of the area of the ventral valve, suggests
both Lingulella and Lingula. It is introduced more to call the attention of sandemts to the
type than as a representative of the genus Lingulella. It is possible that it may belong to the
subgenus Leptembolon of Mickwitz.

Formation AND Locatiry.—Lower Ordovician: (308d) Etage dl, at Swarow; and (303e) Etage di at Sta. Benigna;
both [Barrande, 1879b, Pl. CV] in Bohemia, Austria-Hungary.

LINGULELLA IOLE (Billings).

Plate XX VII, figures 5, 5a.

Lingula iole Bruurnas, 1865, Geol. Survey Canada, Paleozoic Fossils, vol. 1, p. 215, figs. 199a-e. (Described as a new
species. The two specimens represented by figs. 199a-e are redrawn in this monograph, Pl. XXVII, figs. 5
and 5a.)

The type specimens of this species sent to me by Prof. J. F. Whiteaves included single speci-
mens of the ventral and dorsal valves showing only the outer surface, and, where that is exfo-
liated, the surface of the inner layers or lamelle. The surface is marked iar very fine concentric
striz and lines of growth and very fine, obscure, radiating strie upon the outer surface which
are slightly more marked on the inner layers. The edges of the lamellz indicate that the shell
was of moderate thickness, less so than that of Obolus cyane (Billings). The ventral valve has a
length of 7.5 mm.; width, 5 mm.; the dorsal valve is 6 mm. in length and 4.5 mm. in width.

This species is associated aie Obolus cyane and belongs to the same group of species, so far
as can be judged from the external form and appearance of the shell.

The stratigraphic horizon appears to correspond with the upper portion of the Chazy and.
base of the Trenton, of the New York section.

FORMATION AND LOCALITY.—Lower Ordovician: (314d) Limestone of Division P [Billings, 1865a, p. 215] of the
“Quebec group,”’ 4 miles (6.4 km.) northeast of Portland Creek, Newfoundland.

LINGULELLA IRENE (Billings).
Plate XX VII, figures 6, 6a.

Lingula irene Brurnes, 1862, Geol. Survey Canada, Paleozoic Fossils, vol. 1, pp. 71-72, figs. 64a-b. (Described as a
new species. The specimens represented by fies. 64a-b are redrawn in this monograph, Pl. XX VII, figs. 6a
and 6, respectively.)

Lingula irene Bruuines, 1863, Geol. Survey Canada, Fifteenth Rept. Progress, p. 230, figs. 240a-b. (No text reference.
Figures copied from previous reference.)

Lingulella irene (Billings), Scaucuurr, 1897, Bull. U. S. Geol. Survey No. 87, p. 257. (Merely changes generic
reference.)

General form subovate; broadly rounded in front with the ventral valve subacuminate
and the dorsal valve rounded at the beak. Surface of shell marked by concentric lines and
strie of growth and fine radiating strie. ‘Fhe specimens are almost flattened in the shale and
the substance of the shell has been very largely removed, so that it is impossible to determine
the markings upon the surface, the layers of which it may have been formed, or its thickness. A
thickened rim on the ventral ee indicates that the shell was strong and nrobably built up as
in other species of Lingulella. The type specimen, the ventral valve, as compressed in the
shale, has a length of 16.5 mm., with a maximum width of 13. 25mm. The dorsal valve is 15.5
mm. in length and 14 mm. in said,

The area of the ventral valve is strongly marked and relatively long. It is divided midway
by a clearly defined pedicle furrow and toward the lateral margins by sharp flexure lines. Fine

—— ‘tatiana

OBOLIDA. 509

strize of growth cross the arca and the pedicle furrow parallel to its base. The area of the
dorsal valve is partly shown in the figured specimen. It is rather long and marked by numerous
fine transverse striz. The only interior markings preserved are traces of the main vascular
sinus in the ventral valve and a portion of the narrow ridge on each side of the central groove
of the vascular cavity.

Observations.—This is a large fine species that occurs in the siliceous slates at Point Levis.
It may be compared with the Lower Ordovician species, Obolus selwyni (Matthew) and Lingulella
(Lingulepis) robert (Matthew).

Billings [1862b, p. 72] states that a single valve, found in the ‘‘Calciferous sandrock”’
at the eastern end of the island of Montreal, is rather strongly convex, especially on the
umbonal.

ForMATION AND LOCALITY.—Lower Ordovician: (319a [ Billings, 1862b, p. 72]) Levis shales, Point Levis, Quebec,
Canada. :
LINGULELLA IRIS (Billings).

Y Plate XXVII, figure 2.

Tingula iris Biuurnes, 1865, Geol. Survey Canada, Paleozoic Fossils, vol. 1, p. 301, fig. 290. (Described as a new species,
see below for copy. The specimen represented by fig. 290 is redrawn in this monograph, Pl. XX VII, fig. 2.

The original deseription by Billings follows:

Shell small, subovate; sides parallel, or nearly so, in the lower two-thirds gently convex or somewhat straight; in
the upper one-third converging to the beak with a convex slope; beak narrowly rounded; anterior angles rounded;
anterior margin, with a portion in the middle, somewhat straight. The only specimen collected is gently convex, a
somewhat flat space along the middle, and a flat or gently convex slope on each side to the margin in the upper two-
thirds. Surface with obscure radiating and concentric striz. Length, 44 lines; width, 3} lines.

The only specimen of this species in the collection of the Geological Survey of Canada is
the one described by Billings [1865a, p. 301]. It is a dorsal valve with an outline somewhat like
that of Lingulella arguta (Walcott) [Pl. XXIV, fig. 5a].

The character of the limestone matrix and the small fragments of trilobites embedded in
it indicate that the specimen was taken from one of the bowlders of Cambrian limestone embedded
in the Ordovician limestone No. 2 of the Point Levis section [Walcott, 1890a, p. 111].

FORMATION AND LOCALITY.—Upper Cambrian: (319d [Billings, 1865a, p. 301]) Limestone bowlder in Lower Ordo-
vician conglomerate, Point Levis, Quebec, Canada. ;

LINGULELLA IssE (Walcott).

UL
Text figures 43A—-F, page 510, and Plate XX XIX, figures 4, 4a—b.

Obolus (Lingulella) isse Waxcorr, 1905, Proc. U. 8. Nat. Mus., vol. 28, p. 330. (Characterized as a new species.)

This shell is rather strong and made up of several thin layers or lamellze. Its outer sur-
face is marked by concentric lines of growth, sometimes grouped in more or less elevated bands,
and over all there is a thin encrusting or scabrous layer that has a minutely granular, dull
surface, somewhat like that of Lingulella (Lingulepis) gregwa (Matthew), but very much finer
in its granulations or points. The inner layers of the shell are dark, shiny, and marked by
concentric lines of growth and radiating striz. ;

The longest ventral valve has a length of 16 mm. The proportions of length and breadth
of the valves are as follows:

Dimensions, in millimeters, of valves of Lingulella isse ( Walcott).

Length. Width.

longa: nechiate ia: pee sci be aepy unre 16 9
DVemitnalleallviesiycise seer rctacle cs ctelevuate ore eisai tener Ii eye libel Ree esate Cet eae ae en a 10 7
Sloot; Aine! joroRGl, oo ce ace onseseceave 11 9

Blongate BS Eiht) Re ee la 6.5 4.5

STI a EE A Oy eee a tai Sees ae 5 4.5

Morsalevalivessseece aoe. ae so. eee ose ele oerae NEST ie EON ts Cem e eteee 1 85
Slonim! loroeRGl.csosssasc-sesnsssssee 10.5 9

510 CAMBRIAN BRACHIOPODA.

Observations.—The ventral valves of Lingulella isse have an outline very similar to that
of Lingulella pogonipensis (Walcott) and L. acutangula (Roemer) (Pl. XVII), but the dorsal
valves are more subquadrate in outline, and even the elongate form of the dorsal valve is more
obtusely rounded. The species has a considerable vertical distribution in the House Range
section. It is first met with 950 feet (289.6 m.) above the Middle Cambrian, and again at
the 1,150 (350.5 m.) and 1,400 foot (426.7 m.) horizons. Fragments of a closely allied species
occur near the summit of the Upper Cambrian, 2,800 feet (853.4 m.) above the Middle Cambrian,
and a single dorsal valve was collected from the Weeks limestone of the Middle Cambrian,
650 feet (198 m.) below the base of the Upper Cambrian. If these two somewhat doubtful,

but still closely allied, shells are identical the known vertical range of the species is 3,450 feet, ~

(1,052 m.), a range that may be compared with that of Obolus mcconnelli (p. 397) and L. desid-
erata (p. 493).

The original description of the species [Walcott, 1905a, p. 330] referred it to the Middle
Cambrian, but later collections from the House Range section show this reference to have
been incorrect, as the associated
fauna occurs in the Orr formation
30 miles to the south.

FORMATION AND LOCALITY.—Upper Cam-
brian: (15d) @ Thin-bedded blue limestone near
Cave Spring on the east side of the Fish Spring
Range, about 4 miles (6.4 km.) south of the

, Jd. J. Thomas ranch; and (33d) thin-bedded

C plue limestone from the same horizon as

locality No. 15d at the base of the first high

point southwest of the J. J. Thomas ranch,

on the east side of the Fish Spring Range;
both in Juab County, Utah.

(30j) 950 feet (289.6 m.) above the Mid-
dle Cambrian and 2,450 feet (746.8 m.) below
the top of the Upper Cambrian, near the base
of the arenaceous shales and limestone form-
ing le of the Orr formation [Walcott, 1908f,

ec ee era nee nr on tee p17) on Or Ridge abou 5 miles (km)
Nat. cee Cat. Ne. SIRO): ©, ¢, Gaia aie (U. 8. Nat. Mus. Cat. No. 569984), S°uth of Marjum Pass; (30k) 1,150 feet (350.5
D, D’, Dorsal valve (U.S. Nat. Mus. Cat. No. 56998b). E, Dorsal valve (U. S. Nat. ™.) above the Middle Cambrian and 2,175
Mus. Cat. No. 56998c). F, Young shell tentatively referred to this species (U.S. Nat. feet (662.9 m.) below the top of the Upper
MAUS (Cie IN GIEREAD). Cambrian, at the top of the arenaceous shales
The specimens represented by figures 43A and 43B are from Locality 830k; those rep- and limestones forming le of the Orr forma-

resented by figures 43C, 43D, 43E, and 43F are from Locality 30j; both in the Upper : :
e jl
Cambrian limestones of the Orr formation, House Range, Millard County, Utah. tion [Walcott, 1908f, P 176], on Orr R: dge,

about 5 miles (8 km.) south of Marjum Pass;
(30y) about 1,400 feet (426.7 m.) above the Middle Cambrian and 1,900 feet (579.1 m.) below the top of the Upper
Cambrian in the supposed metamorphosed equivalent of the shales forming 1b of the Orr formation [Walcott, 19088,
p. 176], above the granite contact on top of the ridge north of Notch Peak; (81q) about 2,800 feet (853.4 m.) above the
Middle Cambrian and 500 feet (152.4 m.) below the top of the Upper Cambrian in the gray limestone forming Ja of
the Notch Peak limestone [Walcott, 1908f, p. 175], on the north slope of Notch Peak; all in the House Range [Walcott,
1908f, Pls. XIII and XIV], Millard County, Utah.

(34r and 34t) Limestone 1.5 miles (2.4 km.) northwest of Wahwah Springs, on the north side of the road at Cane
Pass, Wahwah Mountains, Beaver County; (32g) about 2,575 feet (784.9 m.) above the Cambrian quartzitic sand-
stones in a blue limestone about 2 miles (3.2 km.) southeast of Muskrat Spring, on the northwest face of Grantsville
Peak, Stansbury Range, Tooele County; and (80s) green shale about 1,200 feet (365.8 m.) above the Cambrian quartz-
itic sandstones on the pipe line above the limekiln in Ogden Canyon 1 mile (1.6 km.) above its mouth, east of Ogden,
Weber County; all in Utah.

(313) Limestone 0.75 mile (1.2 km.) east-northeast of McGill post office, White Pine County, Nevada.

(57d) About 3,215 feet (980 m.) above the Middle Cambrian and 375 feet (114.3 m.) below the top of the Upper
Cambrian in green shales near the summit of 2b of the Sherbrooke limestone [Walcott, 1908f, p. 204], on ridge west
of Mount Bosworth, on the Continental Divide between Alberta and British Columbia, just north of the Canadian
Pacific Railway, Canada.

a The species also occurs in Locality 34i (p. 196).

OBOLIDA. 511

Middle Cambrian: (30n) About 3,750 feet (1,143 km.) above the Lower Cambrian and 650 feet (198 m.) below
the Upper Cambrian in the shaly limestones forming Ic of the Weeks limestone [Walcott, 1908f, p. 175], on the north
side of Weeks Canyon, about 4 miles (6.4 km.) south of Marjum Pass, House Range [Walcott, 1908f, Pl. XIII], Millard
County; and (81y) thin-bedded limestone about 125 feet (88 m.) above the Cambrian quartzitic sandstones, in the
Wasatch Mountains, 1 mile (1.6 km.) northwest of Geneva, east of Brigham, Boxelder County; both in Utah.

(54s) Dark blue-gray Langston limestone [ Walcott, 1908f, p. 198], just above the Cambrian quartzitic sandstones,
north side of Twomile Canyon, near its mouth, 2 miles (3.2 km.) southeast of Malade, Oneida County, Idaho.

(57n)@ About 3,000 feet (914.4 m.) above the Lower Cambrian and about 700 feet (213.4 m.) above the base of
a limestone correlated with No. 4 of the Eldon limestone on Mount Bosworth [Walcott, 1908f, p. 209], on the north-
west slope of Mount Stephen, above Field on the Canadian Pacific Railway, British Columbia.

LINGULELLA KIURENSIS (Waagen).
Plate XXX, figures 5, 5a, 6, 6a.

Lingula ? kiurensis WAAGEN, 1885, Mem. Geol. Survey India, Paleontologia Indica, 13th ser., Salt Range Fossils, vol.
1, pt. 4, fas. 5, pp. 768-769, Pl. LXX XVI, figs. 8a-b. (Described and discussed as a new species, see below.
The specimen represented by figs. 8a-b is redrawn in this monograph, Pl. XXX, fig. 6.)

Lingula? wartht WAAGEN, 1885, idem, pp. 769-770, Pl. LXX XVI, figs. 9a-b. (Described and discussed as a new
species. The specimen represented by figs. 9a—b is redrawn in this monograph, Pl. XXX, fig. 5.)

Lingula ? kiwrensis WAAGEN, 1891, idem, vol. 4, pt. 2, Pl. II, figs. 17a-b. (No text reference. Figures copied from
those representing L. wartht Waagen, 1885, Pl. LX X XVI, figs. 9a and 9b. Figures 17a~b are reproduced in this
monograph, Pl. XXX, fig. 5a.)

Lingula? warthi WAAGEN, 1891, idem, vol. 4, pt. 2, Pl. II, figs. 18a-b. (No text reference. Figures copied from
those representing L. kiurensis Waagen, 1885, Pl. LXX XVI, figs. 8a and 8b. Figs. 18a—b are reproduced in
this monograph, Pl. XXX, fig. 6a.)

Through the courtesy of the director of the Geological Survey of India, Mr. T. H. Holland,
I have had the opportunity of studying the type specimens of the two species described by
Waagen. Of Lingulella kvurensis, Waagen mentions [1885, p. 769] that he had a single speci-
men, which he considered to be a ventral valve. He also had but one specimen of the second
species, ‘‘Lingula? warthi,” which he could not decide as either a ventral or dorsal valve. I
find that the two specimens are from the same locality and from the same bed of rock. Waagen
stated [1885, p. 770] that he long considered them as belonging to the same species, but owing
to the existence of a ‘‘reticulation” on the lateral parts of ‘‘Z.? warthi” he decided to separate
the latter as a distinct species. In a reflected light I find traces of the ‘‘reticulation” on the
outer portions of L. kwrensis, and it is quite common in an arenaceous matrix to find shells
from which the finely reticulated outer surface has been abraded. My interpretation of the
two specimens is that they represent one species, and that Waagen’s type of ‘‘Lingula? warthi”’
is the ventral valve and the type of his ‘‘Lingula? kiurensis” the dorsal valve. Carefully
made drawings have been prepared of the two type specimens, and beside them are repro-
duced the somewhat diagrammatic figures accompanying Waagen’s description.

In 1891 Waagen refigured [1891, Pl. II, figs. 17a—b] the specimen which he described in
1885 [1885, p. 769] as ‘‘Lingula warthi” and labeled it ‘‘Lingula? kiurensis.” Similarly, the
specimen which he described [1885, p. 768] as ‘‘Lingula? kiurensis”’ is [1891, PI. II, figs. 18a—b]
labeled ‘‘Lingula? warthi.”

The original description by Waagen follows:

The general form of the shell is an elongate oval with the ventral valve slightly more acuminate than the dorsal;
original convexity unknown, as both specimens are flattened in the matrix and one is slightly crushed. Surface
marked by round striz of growth that vary in size, and a few narrow, irregular, rounded, radiating ribs on the sides.

“Waagen [1885, p. 768] described this species under the impression that it was from the
Productus limestone of the Carboniferous. Subsequently, this view was modified on account
of the discovery of Cambrian fossils by Warth. The history of the discoveries and discussion
is very clearly presented by Noetling [1894, pp. 71-86] in an article on the ‘‘Cambrian forma-
tion of the Salt Range.”’

The first impression made by this shell when comparing it with other species of Lingulella
is that it is an Upper Cambrian type. Its broad oval outline is not unlike that of Lingulella

a The species is somewhat doubtfully identified from this locality.

512 CAMBRIAN BRACHIOPODA.

bella (Walcott), of Newfoundland, Lingulella davist (McCoy), of Wales, L. mosia osceola
(Walcott), and Obolus (Westonia) stoneanus (Whitfield), of Wisconsin. No such forms are
known to me from the Lower Cambrian, and the broad shells from the Middle Cambrian are
usually more acuminate.

The specific name is derived from Kiura, the type locality.

ForMATION AND LOCALITY.—Middle Cambrian: (357 [Waagen, 1885, p. 769]) Limestones in the ‘‘Neobolus beds”’
of the Khussak group; above the salt mines at Kiura (Khewra), Salt Range, India.

LINGULELLA L&viIs Matthew.
Plate XIX, figures 4, 4a-b.

Lingulella levis MatrHEW, 1892, Trans. Roy. Soc. Canada for 1891, Ist ser., vol. 9, sec. 4, No.-5, p. 39, Pl. XII, figs.
4a and 4b. (Described as a new species, see below for copy. The specimens represented by figs. 4a and
4h are redrawn in this monograph, Pl. XIX, figs. 4a and 4, respectively.)

The original description by Matthew follows:

A large oval-ovate species, with a very thin test, resembling a Lingula in its thin hinge line, and having a
pedicle groove.

The shell has a smooth, shining surface, but when observed with a lens very fine concentric and fainter radiating
lines are made visible.

Ventral valve, length, 15 mm.; width, 11 mm. Dorsal valve, length, 14 mm.; width, 11 mm. Another dorsal
valve is 17 mm. long and 15 mm. wide.

This is a very interesting species on account of the thinness of the shell and the unusual
outline of the dorsal valve. It is unfortunate that the material for study does not show the
interior of the valves.

FORMATION AND LOCALITY.—Upper Cambrian: (301n) Shales of Division C3a of Matthew [1892, p. 39], on the right
shore below the ‘‘falls,’’ St. John Harbor, St. John County, New Brunswick.

LINGULELLA L2&VIS GRANDIS Matthew.

Plate XIX, figure 4c.

Lingulella levis grandis MartHEw, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, pp. 200-201,
Pl. XV, figs. la-d. (Described and discussed as a new variety. The specimen represented by fig. 1d is
redrawn in this monograph, Pl. XIX, fig. 4c.)

Matthew considers this shell a variety of Lingulella levis. It is somewhat larger, but
a good series of specimens would probably unite the two forms. Matthew [1903, p. 201] gives
a very elaborate description of the interior of the valves. He sent me the type of the dorsal
valve, which is illustrated (fig. 4c). I could not discover many of the markings indicated in
his illustration, but the latter may be a composite drawing.

ForMATION AND LOCALITY.—Upper Cambrian: (325b [ Matthew, 1903, desc. of Pl. X V]) Sandy shales of Division
O8a of Matthew, at Escasonie shore, Hast Bay, east of Bras d’Or Lake, im eastern Cape Breton, Nova Scotia.

(301t [Matthew, 1903, p. 201}) Sandy shales of Division C3a of Matthew, at Carlton shore, near the suspension
bridge, St. John, St. John County, New Brunswick.

LINGULELLA LENS (Matthew).
Plate XX XIII, figures 1, la-d.

Lingula ? lens MarrHEw, 1901, Bull. Nat. Hist. Soc. New Brunswick, vol. 4, pt. 4, No. 19, pp. 274-275, PI. V, figs. 3a—h,
(Described and discussed as a new species. The specimen represented by fig. 3a is redrawn in this monograph,
Pl. XX XIII, fig. 1.)

Obolus (Lingulella) bellus Waucorr (in part), 1901, Proc. U. S. Nat. Mus., vol. 23, pp. 685-687. (Matthew’s ‘‘Zingula
lens’’ is here described with, and referred to, “‘Obolus (Lingulella) bellus.’’)

Obolus (Lingulella) lens (Matthew), Waxcorrt, 1902, idem, vol. 25, pp. 606-607. (Described and discussed as a distinct
species. ) :

Lingulella levis lens Marraew, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, pp. 201-203, Pl. XV,
figs. 3a-h. (Matthew’s original ‘‘Lingula ? lens” is here described and discussed as a variety of Lingulella lxvis.
The description is an essential copy of and the figures are copied from Matthew, 1901, pp. 274-275, PI. V, figs.
3a-h.) °

Lingulella lens MarrHEw, 1903, idem, pp. 205-206. (Discussed as not belonging under Westonia.)

OBOLIDA. 513

Not Obolus (Palxobolus) lens Marrunw, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, pp. 144-146,

Pl. X, figs. la-f. (Referred in this monograph to Obolus (Palxobolus) bretonensis lens.)

General form broadly ovate. The ventral valve is subacuminate and the dorsal valve very
broadly ovate to subsemicircular. The convexity of the valves is moderate, the ventral valve
being most prominent along the center, with the posterolateral slopes somewhat flattened
toward the margin.

Surface of the shell marked by fine, concentric striz and lines of growth, and the inner
surface by concentric lines and very fine radiating striez. The shell is thinner than most species
of the genus, resembling in this respect Obolus? murrayi Billings, Lingulella levis Matthew,
and L. bella (Walcott). It is formed of several layers or lamellae that are slightly oblique to
the outer layer. Matthew [1901, p. 274] speaks of minute pits on the outer surface. These
also appear on the inner layers. I have been unable to determine whether the thin calcareous
crust mentioned by Matthew [1901a, p. 274] is really the true outer layer or simply a thin calca-
reous deposit.

The largest specimen of a dorsal valve in the collection has a length of 15 mm., with a
width of 13 mm. The corresponding ventral valve was probably 1 or 2 millimeters longer.

Observations.—In the material collected by Loper in 1901 there are some specimens that
show the form of the ventral and dorsal valve of this species. The shell is broader and rounder
than I supposed when studying the material Matthew sent me. It is quite distinct from Lin-
gulella bella (Walcott) and L. concinna Matthew, with which I placed it. The interior markings
are those of Lingulella, but it may be that more perfect material would prove it to belong to
one of the subgenera of Obolus.

Matthew [1903, p. 201] refers to this form as a variety of Lingulella levis. With the mate-
rial from Cape Breton and Newfoundland for comparison, I am not sufficiently sure to follow
him in this, as it appears to be specifically distinct from levis.

Further remarks on this species occur under Lingulella concinna (p. 487).

ForMATION AND LOCALITY.—Upper Cambrian: (10r)@ Thin calcareous layers in the arenaceous shales of Division
3a? of Matthew at McAdam shore, Hast Bay, east of Bras d’Or Lake, eastern Cape Breton, Nova Scotia.

LINGULELLA LEOS (Walcott).
Plate XXIV, figures 2, 2a-c.

Obolus (Lingulella) leos Watcorr, 1898, Proc. U. S. Nat. Mus., vol. 21, p. 407-408. (Described and discussed essen-
tially as below as a new species. )

Shell small; general form elongate ovate with the ventral valve subacuminate.. The
valves are rather strongly convex in the narrow form of the species. Average length of a
ventral valve is 5 mm.; the largest ventral valve has a length of 6 mm.; the dorsal valve is
somewhat shorter. The width of the valve varies considerably in shells occurring in the
same hand specimens in the limestone. This is shown by Plate XXIV, figures 2 and 2a, for the
ventral valve, and 2b and 2c for the dorsal valve. The surface of the shell is marked by fine con-
centric lines and striz of growth, and very fine, interrupted, radiating strie; casts of the inte-
rior of the shell show stronger radiating striz than the outer surface; also in many specimens
unusually large papille that fill the pits or puncte of the inner surface. The number and
strength of the papille vary in different casts. The shell appears to have been rather thin,
and formed of a thin outer layer and one or more thin inner layers or lamellz.

Casts of the interior of the ventral valve show a well-defined area, divided midway by
the cast of a strong pedicle groove. The area of the dorsal valve is obscured by adhering
fragments. On casts of the ventral valve traces of the visceral cavity (v) and the main vascular
sinuses (vs) occur, and in the dorsal a narrow, long median sinus is clearly defined; also the
casts of the central and anterior lateral muscle scars (Pl. XXIV, figs. 2b and 2c).

a10r is the type locality, though the specimens in the United States National Museum collections to which that number is assigned were
collected later than the type specimens.

62667°—vo1 51, pr 1—12——_33

514 CAMBRIAN BRACHIOPODA.

Observations. —This neat little species in some respects resembles Lingulella similis (Walcott).
It differs, as may be seen by comparing Plate XXIV, figures 2, 2a-c, with Plate X XI, figures 2,
2a-c, in being more elongate, the interior more strongly punctate, and in the more anterior
position of the central muscle scars in the dorsal valve.

ForRMATION AND LOCALITY.—Upper Cambrian: (96) Limestones near the ford on the Cedartown road, 1.5 miles
(2.4 km.) south of Rome, Floyd County, Georgia.

LINGULELLA LEPIS (Salter).

ie

Lingula lepis Sauter, 1859, Siluria, by Murchison, 3d ed., p. 543.

Plate XXXI, figures 4, 4a-f.

Lingulella lepis Saurer, 1866, Mem. Geol. Survey Great Britain, vol. 3, p. 334, fig. 11. (Described and discussed as

a new species.) ;

Lingula? lepis Salter, Davipson, 1866, British Fossii Brachiopoda, vol. 3, pt. 7, No. 1, p. 54, Pl. 10, figs. 53-59.
(Described and discussed. Figs. 58-56 are reversed views of Salter, 1866b, p. 334. fig. 11.)

Lingula (Lingulella) lepis (Salter), Davipson, 1866, idem, description of Plate II]. (Merely changes generic reference.)

Lingulella lepis (Salter), Davipson, 1868, Geol. Mag., vol. 5, pp. 307-308, Pl. XV, figs. 10-12. (Discussed. Figs.
10 and 10a are copied (reversed) from the upper two of Salter’s figures, 1866, p. 334, fig. 11.)

Lingulella lepis (Salter), Davipson, 1871, British Fossil Brachiopoda, vol. 3, pt. 7, No. 4, Pl. XLIX, figs. 31 and 31a.
(Figs. 31 and 3la are reproduced in this monograph, Pl. XX XI, figs. 4a and 4, respectively.)

Lingulella lepis (Salter), SarreR and EreripceE, 1881, Mem. Geol. Survey Great Britain, vol. 3, 2d ed., p. 538, fig.
1l. (A copy of Salter, 1866b, p. 334, fig. 11.)

Lingula (Lingulella?) lepis (Salter), BROGGER, 1882, Die silurischen Etagen 2 und 3, p. 44, Pl. X, figs. 5, 5a-b. (Occur-
rences mentioned in German.)

Lingulella lepis (Salter), Horm, 1898, Geol. Féren. i Stockholm Férhandl., Bd. 20, p. 148. (Occurrences mentioned
in Swedish.)

Lingulella lepis (Salter)?, Wmran, 1902, Bull. Geol. Inst. Univ. Upsala, vol. 6, pt. 1, No. 11, pp. 66 and 71. (Occur-
rences mentioned in German.)

Lingulella cf. lepis (Salter), MarrHew, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, p. 204. (New
locality mentioned.)

Lingulella lepis (Salter), Moppre and SEGeRBERG, 1906, Medd. fran Lunds Geol. Faltklubb, Ser. B, No. 2 (Aftryck
ur K. Fysiografiska Sallskapets Handl., N. F., Bd. 17), pp. 62-63, Pl. I, fig. 20. (Occurrences discussed in
Swedish.)

Lingula? corrugata Mopera and SrcrrBere, 1906, idem, p. 63, Pl. I, fig. 21. (Characterized in Swedish as a new
species. ) ;

Lingula ? bryograptorum Mospere and SEGERBERG, 1906, idem, p. 63, Pl. I, fig. 22. (Characterized in Swedish as a
new species.)

Lingula ? producta Mopnre and SrGERBERG, 1906, idem, p. 63, Pl. I, fig. 23. (Described in Swedish as a newspecies.)

Lingula ? ordovicensis MoBere and SEGERBERG, 1906, idem, p. 63, Pl. 1, fig. 24. (Described in Swedish as a new
species. )

Lingulella lepis Salter ?, WesterRGARD, 1909, Medd. fran Lunds Geol. Faltklubb, Ser. B, No. 4 (Aftryck ur K. Fysio-
erafiska Sillskapets Handl., N. F., Bd. 20), p. 56, Pl. Il, figs. 17-19. (Discussed in Swedish. Figs. 17 and 18
are copied from Moberg and Segerberg, 1906, Pl. I, figs. 28 and 27, respectively.)

Lingula? corrugata Moberg and Segerberg, WesteRGARD, 1909, idem, p. 57, Pl. Il, fig. 23. (Characterized in
Swedish. Fig. 23 is copied from Moberg and Segerberg, 1906, Pl. I, fig. 21.)

Lingula? bryograptorum Moberg and Segerberg, WestERGARD, 1909, idem, p. 57, Pl. II, figs. 24a-b. (Characterized
in Swedish. Figs. 24a-b are copied from Moberg and Segerberg, 1906, Pl. I, figs. 22a-b, respectively.)

I was in doubt about this species until after studying a fine series of specimens collected
for me by Schmalensee at various localities in Sweden. The Swedish shells, in a limestone
matrix, have a broader outline than the typical forms of Lingulella ferruginea, m a limestone
matrix, although some of the latter are as broad when flattened in the matrix. When the shells
of L. lepis are compressed laterally they look very much like those of L. ferruginea Salter.
Under like conditions of preservation they appear to be distinct. The interior surface is marked
by concentric lines of small pits. The outer surface varies from an almost smooth and polished
surface marked by concentric lines of growth to a broken surface marked by concentric lines
and radiating, more or less irregular, raised ribs. All the characters known are illustrated
on Plate XXXI.

The American representative of this species, Lingulella bella (Walcott), which has a strati-
graphic range similar to that of the shell from Wales, from the Upper Cambrian into the Lower

Oar wees Pam

+a as iar

OBOLIDA. 515

Ordovician, appears to be a much larger shell. In Norway and Sweden it occurs in the Cerato-
pyge limestone. Compressed and flattened shells from the Paradoxides davidis zone of Manuels
Brook, Newfoundland, strongly suggest this species, but no sunilar forms occur in the calcareous
layers interbedded in the shales, although L. ferrugimea Salter is abundant in both limestone
and shale.

Moberg and Segerberg [1906, pp. 62-63] have described and illustrated five species of small
Tingulella-like shells from the Ceratopyge zone of Sweden. The form illustrated as Lingulella
lepis (Salter) [Moberg and Segerberg, 1906, PI. I, fig. 20] is a dorsal valve of that species from the
Dictyograptus zone. The form given the name Lingula? corrugata Moberg and Segerberg
[1906, Pl. I, fig. 21] is from the lower portion of the Dictyograptus zone and appears to be a
partly exfoliated dorsal valve of L.lepis. Of the remaining two species, the one named Lingula?
ordovicensis Moberg and Segerberg [1906, Pl. I, fig. 24] is much like the ventral valve of L.
lepis as illustrated on Plate XXXI, figure 4b, of this work, and the other, Lingula? producta
Moberg and Segerberg [1906, Pl. I, fig. 23], appears to be a similar shell laterally compressed.
I have a series of specimens from the Ceratopyge limestone of Norway and Sweden that indicate
that the species had a considerable range of variation, in this respect resembling L. ferruginea
Salter (P]. X XIX, figs. 1 and 2); im fact the variations of the latter species nearly include
the forms referred to L. lepis (Pl. XX-X1, figs. 4, 4a-f). It may be that Moberg and Segerberg’s
specific names should be retained, but with the information now available I am inclined to
consider them all as synonyms of L. lepis.

The specific name is derived from 2ezéc, a scale.

ForMATION AND LOCALITY.—Passage beds from the Upper Cambrian to the Ordovician: (8x) Ceratopyge lime-
stone at Slemmestad, about 3 miles (4.8 km.) southwest of Christiania; (323f and 323h [Brégger, 1882, pp. 16-17])
Ceratopyge limestone at Vestfossen, 10 miles (16.1 km.) west-southwest of Christiania; and (328¢ [Brégger, 1882, p. 44])
Ceratopyge limestone in the Christiania region; all in Norway.

(320w [Holm, 1898, p. 148]) Ceratopyge limestone at Glote in Herjeadalen, Province of Jemtland; (310 [Moberg
and Segerberg, 1906, p. 63]) Ceratopyge limestone (zone 4) at Ottenby, Oeland Island; (310j) Ceratopyge limestone at
Borgholm, Oeland Island; (310w [Westergard, 1909, desc. of Pl. II]) zone ¢ at Gronhdgen, Oeland Island; and (809
[Mobere and Segerberg, 1906, p. 63]) Ceratopyge limestone (zone 4) at Fogelsang, 5 miles (8 km.) east of Lund, Province
of Malméhus; all in Sweden.

Upper Cambrian: (9f) Limestones of the Olenus zone at Noersnees, west of Christiania; and (323a [Wiman, 1902,
p- 66]) Ceratopyge slate in the Christiania region; both in Norway.

(3211 and 321m6) Drift bowlders of Ceratopyge slate, Nos. 14, 17, and 27 [Wiman, 1902, p. 68], on Biludden,
about 20 miles (32.2 km.) east of Gefle, Province of Gefleborg; (809a [Moberg and Segerberg, 1906, p.62]) Bryograptus
slate (zone 2) at Fogelsang, 5 miles (8 km.) east of Lund, Province of Malméhus; (310d) Ceratopyge slate at Borgholm,
Oeland Island; and (309b [Moberg and Segerberg, 1906, p. 63]) Dictyograptus slate (zone 1) at Flagabro, Province of
Malméhus; all in Sweden.

(305a [Davidson, 1866, desc. of Pl. III]) Upper Tremadoc beds at Moel-y-gest, northwest side, Carnarvonshire;
(866q [Davidson, 1866, p. 54]) Upper Tremadoc beds at Garth, opposite Portmadoc, Merionethshire; (305e | Davidson,
1866, p. 54]) Upper Tremadoc beds near Tai-hirion, Arenig; (305¢) Lower Tremadoc slate, everywhere in the Tremadoe
district, Carnarvonshire; (305d) 7 5 Upper Lingula flags near Tremadoc, Carnarvonshire; (805f)@ Lower Tremadoc, east
of Port Nant-y-Ladron, on the Bala Road from Ffestiniog, Merionethshire; (305g) @ Lower Tremadoc at Wern; (05h) @
Lower Tremadoc at Borthwood; (3051)% Lower Tremadoc at Trwyn-y-lago; and (305j)@ Lower Tremadoc at Cefn Cyfar-
nedd; all in North Wales. i

(307a [Matthew, 1903, p. 240])> Shales of Division C3c2 of Matthew, on McLeod Brook (=Barachois River), near
Boisdale, eastern Cape Breton, Nova Scotia, Canada.

(301e)> Beds of Division C3a of Matthew; and (801u) shales of Division C3b of Matthew; both [Matthew, 1903,
p. 204] in the St. John Basin, St. John County, New Brunswick, Canada.

LINGULELLA LINEOLATA (Walcott).
Plate XLVIII, figures 2, 2a-l.
Obolus (Lingulella) lineolatus Waxcort, 1898, Proc. U. 8. Nat. Mus., vol. 21, pp. 408-409. (Described and discussed
essentially as below as a new species.)

General form ovate, with the ventral valve subacuminate, and the dorsal valve ovate to
broad ovate. The range of variation in the outline of the valves is quite strongly marked; this

@ Davidson, 1866, p. 54. b The species is somewhat doubtfully identified from this locality.

516 CAMBRIAN BRACHIOPODA.

may be seen by comparing Plate XLVIII, figures 2a, 2e, 21, and 2k of the ventral valve and
figures 2b, 2c, 2d, 2f, and 2g of the dorsal valve. The convexity of the valves is moderate,
that of the dorsal valve being a little more than that of the ventral (fig. 2]).

The surface of the shell is marked by concentric lines and striz of growth, with very fine,
concentric striz between them that are sometimes slightly undulating; on some specimens very
faint radiating striz can be seen with a strong lens; when the outer layer is exfoliated the inner
layer is marked by fine radiating and concentric striz in addition to the stronger concentric
‘strie; as far as can be determined from the imperfect casts of the interior the inner surface of
the shell was nearly smooth. The shell appears to be formed of a very thin outer layer and
one or more thin inner layers or lamelle; toward the frontal margins the oblique lamelle increase
in number, but do not give any considerable thickness to the shell.

One of the largest of the ventral valves referred without doubt to this species has a length
of 7 mm. and a width of 5.5 mm. An associated dorsal valve is slightly shorter in proportion
to the width. The average size is smaller, not exceeding 5 mm. for the length of the ventral
valve. One unusually large ventral valve that is referred to this species with some doubt has
a leneth of 9 mm.

The only traces of the interior of the shell that have been observed are portions of the
cardinal area and pedicle furrow of the ventral valve (Pl. XLVIII, fig. 2]) and the cardinal
area of a dorsal valve (Pl. XLVIIL, figs. 2f and 2 1).

Observations.—This species is very abundant in the upper beds of the ‘“Tonto” sandstone.
It is associated with Obolus ( Westona) euglyphus (Walcott), and it is often difficult when the
two are in the form of imperfect casts, to distinguish between the larger specimens of the two
species. They are readily distinguished, when the shells are well preserved, by the difference
in surface markings and the more acuminate ventral valves of Lingulella lineolata. The latter
character, however, is not always of service, especially in the larger shells. In form the ventral
valve of this species may be compared with L. acutangula (Roemer) (Pl. XVII).

ForMATION AND LOCALITY.—Middle Cambrian: (90) Siliceous limestone about 15 feet (4.5 m.) above the Coronado
quartzite [Lindgren, 1905, p. 3], 0.5 mile (0.8 km.) southwest of Milk ranch, on the first spur north of the one which
the main road follows; and (858) argillaceous shale, 50 feet (15.2 m.) above the Coronado quartzite [Lindgren, 1905,
p. 3], west side of Chase Creek Canyon, 1.5 miles (2.4 km.) east-northeast of Morenci; both in the Clifton quadrangle
(U.S. Geol. Survey), Graham County, Arizona.

(73) Sandstones of the Tonto group, in Kwagunt Valley; (73a) sandstones of Tonto group, in Chuar Valley; (74)
sandstone about 300 feet (91.4 m.) above the base of the Tonto group, at the head of Nunkoweap Valley; (74d) sandstone
beds in ‘‘Tonto” shale, just above massive sandstones near the mouth of Bass Canyon, on the south side of the Grand
Canyon, southeast of Powell Plateau; and (17¢) sandy limestone 235 feet (71.6 m.) above the ‘‘Tonto” sandstone,
Grand View trail, north of Last Chance copper mine, south side of the Grand Canyon; all in the Grand Canyon of the
Colorado, Arizona.

LINGULELLA LINNARSSONI (Walcott).

Plate XXX, figures 14, l4a.
Obolus (Lingulella) linnarssoni Watcorr, 1901, Proc. U.S. Nat. Mus., vol. 23, p. 688. (Described as below as a new
species. )

Ventral valve elongate oval, subacuminate. Surface marked by fine, undulating, depressed,
radiating, ridgelike lines; closely undulating, concentric striz; and very fine papille that
appear to terminate in fine sharp points; the papillz are situated on the narrow, irregular,
elevated spaces between the strize. Shell relatively thin and formed of several lamelle more
or less oblique to the outer surface.

Observations.—The species is based on a fine specimen of a ventral valve associated with
Billingsella lindstrémi (Linnarsson) in the Paradozxides series of Lovened. It is broader than
Lingulella ferruginea Salter and the surface ornamentation is quite different. The latter is
more like that of the associated Acrothele coriacea Linnarsson. In outline it approaches more
nearly to L. lepis (Salter).

The specific name was given in honor of Mr. J. G. Linnarsson.

FoRMATION AND LOCALITY.—Middle Cambrian: (320n) Limestones of the Paradoxides forchhammert zone at Lovened,
Djupadal, 19 miles (30.6 km.) south-southeast of Skara, Province of Skaraborg, Sweden.

*
Fs
3
7
%
i

OBOLIDZA. oly

p LINGULELLA MANTICULA (White).

Plate XX, figures 1, la-c.

Lingula? manticula Waite (in part), 1874, U. S. Geog. Surveys W. 100th Mer.; Prelim. Rept. Invertebrate Fossils,
pp. 9-10. (Described asa new species, including specimens referred to both Lingulella manticula and L. arguta.)

Lingula manticula Warts (in part), 1877, U. S. Geog. Surveys W. 100th Mer., vol. 4, pt. 1, p. 52, Pl. III, fig. 2b (not
fig. 2a). (Described essentially as in the preceding reference and discussed. The specimen represented by fig.
2b could not be located when the drawings of this species were being made, and the original drawing is reproduced
in this monograph, Pl. XX, fig. 1c. The specimen represented by fig. 2a is referred in this monograph to Lingu-
lella arguta.)

Not Lingula? manticula Waucort, 1884, Mon. U.S. Geol. Survey, vol. 8, pp. 13-14, Pl. IX, fig. 3; and Pl. XI, fig. 2.

(These specimens are now referred to Lingulella punctata.)

Shell small, general form elongate ovate, with the ventral valve subacuminate, and the
dorsal valve ovate im outline. Valves rather strongly convex, the ventral being slightly more
so along the posterior half than the dorsal. There is some variation in the outline of the valve,
as is shown for the ventral by Plate XX, figures 1 and ic, and for the dorsal by Plate XX, figures
la and 1b. ;

Surface of shell marked by fine concentric lines of growth and very fine, slightly irregular
concentric striz; when the outer shell is partly exfoliated the outer surface of the inner layers
is marked by fine, concentric lines and not very distinct radiating striz; the inner surface of the
shell shows concentric lines of growth and a few scattered pits or puncte. The shel! is of
medium thickness and formed of a thin outer layer and one or more inner layers or lamellz.

The average length of the ventral valve is 3.5 mm.; width, 2mm. The associated dorsal
valve of the same width has a length of 3 mm.

As shown in the cast of the interior of the shell the area of the ventral valve is long, clearly
defined, and broken midway by a narrow but strong pedicle groove. It is also marked near its
lateral margins by narrow flexure lines. The striz of growth cross the area parallel with its
base. ‘They are very distinct but do not show on the cast of the pedicle furrow.

The cast of the interior of the ventral valve shows the visceral cavity (v) and the outline of
the heart-shaped pit (x). Im the dorsal valve sufficient is shown to indicate that the visceral
cavity extended forward to about the middle of the shell, and that a narrow median septum was
present.

Observations.—This is a small species that is representative of quite a group of somewhat
similar forms that occur in the Upper Cambrian and Lower Ordovician faunas, both in the
Rocky Mountain and Appalachian regions; Lingulella punctata (Walcott) representing the group
in the Rocky Mountains, and L. desiderata (Walcott) in the Appalachian region.

Of the figures given by White [1877, Pl. III] figure 2b is taken as the type. Figure 2a of
White [1877, Pl. I1T]is a larger shell, which I have referred to L. arguta. The specimens identified
by Walcott [1884b, p. 13] as “‘Lingula? manticula”’ have been referred to L. punctata, as a
comparison with the type of “ Z.? manticula’”’ White shows them to be distinct.

This species was referred to the ‘‘Quebec group” by White [1874, p. 9], and it is probable |
that the horizon at which it occurs will be found to be in the passage beds between the Upper
Cambrian and Lower Ordovician, or what corresponds to the lower part of the Pogonip limestone
of the Eureka, Nevada, section. Since the preceding was written, Spurr collected a few Cam-
brian fossils in southern Nevada among which occurs a form that appears to be identical with
L. manticula. The fragments of trilobites indicate a Cambrian fauna but not its stratigraphic
horizon.

FoRMATION AND LOCALITY.—Lower Ordovician: (202) Pogonip limestone, on the summit of the ridge directly
southeast of the Jackson mine, northwest of Shadow Canyon, Eureka district [Hague, 1892, Atlas], Eureka County;
and (214b) limestone near the middle of the Pogonip limestone, White Pine district, White Pine County; both in
Nevada. ~

Upper Cambrian: (8e) Limestone in Patterson Canyon, west side of the Schell Creek Range; (318f) limestone at

Schellbourne, Schell Creek Range, and (8f) limestone at summit of canyon, 10 miles (16.1 km.) south of Egan Canyon,
east side of Egan Range; all in White Pine County, Nevada.

518 CAMBRIAN BRACHIOPODA.

(61) Limestone in the Dunderberg shale [Walcott, 1908f, p. 184], a little south of the Hamburg mine; and (62)
limestone in the Dunderberg shale [ Walcott, 1908f, p. 184], in canyon immediately north of Adams Hill; both in the
Eureka district [Hague, 1892, Atlas], Hureka County, Nevada.

(301) About 1,400 feet (426.7 m.) above the Middle Cambrian and 1,900 feet (579.1 m.) below the top of the Upper
Cambrian in the shales forming 1b of the Orr formation [ Walcott, 1908f, p. 176], on Orr Ridge, about 5 miles (8 km.)
south of Marjum Pass[Walcott, 1908f, Pl. XIII], House Range, Millard County; (15d) thin-bedded blue limestone near
Cave Spring, on the east side of the Fish Spring Range, about 4 miles (6.4 km.) south of the J. J. Thomas ranch, Juab
County; (32f) thin-bedded siliceous limestone near the top of the Upper Cambrian, about 2 miles (3.2 km.) southeast
of Muskrat Spring, on the northwest face of Grantsville Peak, Stansbury Range, Tooele County; and (80q) limestones
about 2,300 feet (701 m.) above the Cambrian quartzitic sandstones on pipe line above limekiln, in Ogden Canyon,
1 mile (1.6 km.) above its mouth, east of Ogden, Weber County; all in Utah.

(54b) About 1,200 feet (365.8 m.) above the Middle Cambrian, and 25 feet (7.6 m.) below the top of the Upper
Cambrian in the limestones forming 1 of the St. Charles formation [Walcott, 1908f, p. 191]; (31m) about 175 feet
(53.3 m.) above the Middle Cambrian and 1,050 feet (320 m.) below the top of the Upper Cambrian, near the base of
the limestones forming 3 of the St. Charles formation [Walcott, 1908f, p. 192]; and (54e) about 200 feet (61 m.) above
the Middle Cambrian and 1,025 feet (212.4 m.) below the top of the Upper Cambrian, in limestones forming 3 of the
St. Charles formation [ Walcott, 1908f, p. 193]; allin Blacksmith Fork Canyon, about 10 miles (16.1 km.) east of Hyrum,
Cache County, Utah. :

Middle Cambrian: (7i) Limestone just west of the summit on the road east of Schellbourne, Schell Creek Range,
White Pine County; and (7j) limestones at the north end of the Quinn Canyon Range, 1 mile (1.6 km.) northwest of
the Italian Ranch foothills, Nye County; both in Nevada.

In the Nounan limestone in southern Idaho there is a narrow, elongate Lingulella that is
closely allied to LZ. manticula. It differs in being narrower in proportion to the length, in this
respect resembling Lingulella cana (Walcott) (Pl. XX XV, figs. 3, 3a-d) of Nova Scotia.

ForRMATION AND LOCALITY.—Middle Cambrian: (56f) Nounan limestone [Walcott, 1908a, p. 6], in a ridge north

of the creek which flows into Mill Canyon from the west, about 5 miles (8 km.) west-southwest of Liberty and 15
miles (24.2 km.) west of Montpelier, Bear Lake County, Idaho.

LINGULELLA MARTINENSIS Matthew
Plate XX XVIII, figures 1, la-g.

Lingulella dawsoni Matraew (in part) [not (Waxcorr)], 1886, Trans. Roy. Soc. Canada for 1885, vol. 3, sec. 4, No. 3,
pp. 33-34, Pl. V, figs. 9, 9a-c (not fig. 9d). (Described and discussed as a new species, but refers in synonymy
to Walcott, 1884a, p. 15. The specimen represented by figure 9d is referred in this monograph to Lingulella
Serruginea.)

Lingulella martinensis MartHEw, 1890, Trans. Roy. Soc. Canada for 1889, Ist ser., vol. 7, pp. 155-156, Pl. VIII, fig. 4.
(Described as a new species.)

Lingulella martinensis MatrHEw, 1895, Trans. New York Acad. Sci. for 1894-5, vol. 14, pp. 113-114, Pl. I, figs. 6a-d.
(Described and discussed. Fig. 6a is copied from fig. 4 of the preceding reference. The specimens represented
by figs. 6b and 6d are redrawn in this monograph, Pl. XX XVIII, figs. 1d-e, and la, respectively. Figs. 1, 1b,
1c are also drawn from specimens in Matthew’s type material, but further identification is impossible.)

Lingulella ci. granvillensis Walcott, MatrHEw, 1895, idem, pp. 114-115, Pl. II, figs. 7a and 7b. (Described and dis-
cussed.)

General form elongate ovate to subcuneate, with the ventral valve subacuminate, and the
dorsal valve elongate ovate; the cardinal slopes of the ventral valve are nearly straight for fully
one-half the length of the valve. Ventral valve moderately convex; dorsal valve unusually
convex, especially over the umbonal region.

Surface of the shell marked by fine concentric lines of growth, and very fine, irregular
raised striz that form a surface of the type of that of Lingulella radula Matthew and Lin-
gulella (Lingulepis) roberti (Matthew). The undulations cause the striz to touch and blend so
as to give the appearance of inosculation and a network of lmes. The appearance of the sur-
face markings often varies considerably on different portions of the same valve. The interior
surface shows radiating lines and scattered puncte. The shell is preserved largely as casts of
the interior and exterior; it appears to have been built up of a thin outer layer and several
inner layers or lamellee.

OBOLID. 519

The largest ventral valve received from Matthew has a length of 9 mm.; width,6mm. The
area of the ventral valve is long and divided midway by a narrow, tapering pedicle groove, and
toward the lateral margin by a well-marked flexure line. The area of the dorsal valve is unusu-
ally long and well marked; the flexure lines are strong and outline a broad, shallow groove
between them (Pl. XX XVIII, fig. le).

A cast of the ventral valve shows a slight trace of the visceral cavity, also the anterior
lateral muscle scars. A few outlines of the vascular markings are preserved in casts of the
dorsal valve, also the transmedian and outside or middle lateral muscle scars which occur just
within a narrow ridge that borders the somewhat flattened margin of the interior of the valve.

Observations.—The original figure of this species [Matthew, 1890, Pl. VIII, fig. 4] is: quite
unlike those subsequently given by Matthew [1895a, Pl. Il]. The first type must have been
distorted, or else it is a different species.

With original specimens to compare and study I consider the specimens referred to Lin-
gulella cf. granvillensis by Matthew [1895a, p. 114] to be identical with L. martinensis. The size
and form of the valves, convexity, and surface markings all serve to strengthen this conclusion.
The ventral valve, figured by Matthew [1895a, PI. II, fig. 7a], is an impression im the shale, the
cardinal slopes of which have been broken away. The dorsal valve [Matthew, 1895a, Pl. II,
fic. 7b] may be compared with the dorsal valve of L. martinensis [1895a, Pl. II, fig. 6d].

Matthew [1895a, p. 114] described the occurrence of the central and lateral scars in the
ventral valve, but he does not show them in his figures, and I can not clearly see them in the
type specimens received from him.

The specific name is derived from St. Martins, in which the type specimens were collected.

ForMATION AND LOCALITY.—Middle Cambrian: (2g and 2f)@ Sandstones of Division 161; (2h) sandstones of Divi-
sion 1b2; and (2i) sandstones of Division 1b2; all in Matthew’s [1895, p. 108] Protolenus zone on Hanford Brook,
St. John County, New Brunswick. f

LINGULELLA MINOR (Matthew).
v Plate XX XVII, figures 3, 3a-g.

Lingulella starri minor MartHEew, 1892, Trans. Roy. Soc. Canada for 1891, vol. 9, sec. 4, No. 5, pp. 58-59, Pl. XIu,
figs. 5a—b. (Described and discussed as below. It is a new variety, though not so described. The specimens
represented by figs. 5a and 5b are redrawn in this monograph, Pl. XX XVII, figs. 3 and 3a, respectively.)

The original description by Matthew follows:

This neat little species is referred to Lingulella starri on account of the sculpture, though it is different both in form
and size. It is only about two-thirds of the size of that species, and is more prolonged in front. The dorsal valve also
is ovate, not oblately orbicular as in the type.

The sculpture consists of concentric ridges, which appear crenulated owing to the interrupted, faint, radiating
ridges that traverse them. At intervals there are stronger concentric lines marking stages of growth. The ridges are
not so sharply marked as in Z. starri, and the shell is much thinner.

Length of ventral valve, 11 mm.; width, 9mm. The dorsal valve is 1 mm. shorter.

Observations.—The types of Lingulella starri are in this monograph referred to Lingulella
(Lingulepis), and the variety minor of Matthew [1892, p. 58] to Lingulella as a distinct species.
During the summer of 1899 IJ visited the type locality on Long Island, and found this shell
in the shales, and also a smaller shell that appears to be the young of Lingulella minor, im a fine,
compact, shaly sandstone, and in lenticular masses of limestone interbedded im the shales.
There is also great variation in outline and size of the shells m the siliceous shale.

ForRMATION AND LOCALITY.—Upper Cambrian: (2x) © Thin-bedded sandstones of Division 2 of Matthew, on the south
shore of Long Island, Kennebecasis Bay [G. F. Matthew, 1898b, p. 88], St. John County, New Brunswick.

(8n) Thin-bedded sandstones on Salmon River, Gillis Hill, 13 miles (20.9 km.) south of Marion Bridge, eastern
Cape Breton, Nova Scotia, Canada.

a2f is the type locality, though the specimens in the United States National Museum collections to which that number is assigned were
collected later than the type specimens.

62x is the type locality, though the specimens in the United States National Museum collections to which that number is assigned were
collected later than the type specimens.

520 CAMBRIAN BRACHIOPODA.

LINGULELLA MosIA (Hall).

Plate XVIII, figures 1, la-f.

Lingula mosia Hart, 1863, Sixteenth Ann. Rept. New York State Cab. Nat. Hist., p. 126, Pl. VI, figs. 1-3a. (Described
and discussed as a new species; see below.) ;

Lingula mosia Haut, 1867, Trans. Albany Inst., vol. 5, pp. 102-103, Pl. I, figs. 1-3a. (Copy of preceding reference.)

Lingula mosia Hall, Sarvuson, 1896, Bull. Minnesota Acad. Nat. Sci., vol. 4, No. 1, pt..1, p. 95. (Discussed from a
new locality.)

The original description by Hall follows:

Shell small, subelliptical, or ovate-spatulate, little convex, concentrically striated. The slopes below the beak
are sometimes nearly straight for a short distance, and often curving from the beak to the base. The specimens are for
the most part impressions in sandstone, with little of the shell remaining, but the form is very distinct from any of
the described species; and being limited in vertical range, and with a somewhat wide horizontal extension, it becomes
of interest in its associations.

The study of a large number of specimens has added little to the knowledge of this species.
Nearly all the shell structure has been removed, and only more or less imperfect casts remain
in the sandstone. The outer surface is marked by fine concentric striz and lines of growth,
and in one cast there is an indication of irregular, almost inosculating striz, such as occur on
portions of the surface of Obolus (Westonia) ella (Hall and Whitfield). The few fragments of
the shell in the material studied indicate that it was of medium thickness and formed of two
or more layers, and that the inner lamelle were marked by fine radiating striz.

The average size of the ventral valve is about 8.5 mm. in length by 7 mm. in width. The
dorsal valve is a little shorter in proportion to the width.

The area of the ventral valve is high; it is broken midway by a strong narrow pedicle
groove, and on each side, well out toward the margin, by very narrow flexure lines. Strong
strie of growth cross the area parallel to its base. They arch transversely over the cast of
the pedicle furrow. The area of the dorsal valve is well defined; it is crossed by fine striz
of growth, and marked by oblique flexure lines that outline a rather broad space between
them.

The casts of the interior of the ventral valve show traces of the visceral cavity and main
vascular sinuses, and the central and anterior lateral muscle scars have been seen in the dorsal
valve.

Observations.—The broad, almost subquadrate outline of some of the specimens of the
dorsal valve suggest Obolus (Westonia) ella (Hall and Whitfield) (Pl. XLVII) and there is a
trace of the surface of the latter. A closer comparison of the two shows that O. (W.) ella is a
broader shell, with a characteristic surface ornamentation. Lingulella mosia may be the Upper
Cambrian representative of the Middle Cambrian Obolus ( Westonia) ella.

FoRMATION AND LOCALITY.—Lower Ordovician: (364a [Sardeson, 1896, p. 95]) reported by Sardeson from the
Oneota dolomite along St. Croix River in both Wisconsin and Minnesota.

Upper Cambrian: (113) ‘‘St. Croix sandstone” at La Grange Mountain (or Barn Bluff), near Red Wing, Goodhue
County, Minnesota.

(78 and 78s)@ ‘‘St. Croix sandstone,”’ quarry near St. Croix River in suburbs of Osceola, Polk County; (85)?
“St. Croiz sandstone” near Prairie du Sac, Sauk County; (85x and S85x) upper beds of the ‘‘St. Croix sandstone” near
Mazomanie, Dane County; (99a) ‘‘St. Croix sandstone” near Pilot Knob, Adams County; (100) “St. Croix sand-
stone” near Menomonie, Dunn County; (79 and-79s) ‘‘St. Croix sandstone” near Hudson, St. Croix County; (98x)
“St. Croix sandstone” near Eau Claire, Eau Claire County; (78b) ‘‘St. Croix sandstone” 50 feet (15.2 m.) above
St. Croix River, near the landing at Osceola, Polk County; (98a) ‘‘St. Croix sandstone” at Marine Mills, Wash-
ington County; (86) ‘‘St. Croix sandstone,’ at Van Ness’s quarry, Gibraltar Bluff, Lodi, Columbia County; and
(85s) ‘St. Croix sandstone” at Prairie du Sac, Sauk County; all in Wisconsin.

(364) St. Lawrence formation of Sardeson [1896, p. 95], in both Wisconsin and Minnesota.

(341a) Sandstone at McGregor, Clayton County, Iowa.

a The species also occurs in Locality 78¢ (p. 214).
» 85 is the type locality, though the specimens in the United States National Museum collections to which that number is assigned were

collected later than the type specimens. ,

OBOLIDA. - 521

LINGULELLA MOSIA OSCEOLA (Walcott).

Plate XVIII, figures 2, 2a-c.

Obolus (Lingulella) mosia osceola Watcort, 1898, Proc. U. 8S. Nat. Mus., vol. 21, p. 409. (Characterized as below as a
new variety.)

There is a considerable variation in the form of Lingulella mosia (Hall) as it occurs in the
.brown sandstone of Osceola, and for the narrow, more elongate variety the name osceola
was proposed [Walcott, 1898b, p. 409]. It is an intermediate form between L. mosia and L.
perattenuata (Whitfield) (Pl. XXI). The same, ora closely allied, variety occurs in a light-colored
sandstone at Hau Claire.

The varietal name is derived from Osceola, the type locality.

FORMATION AND LOCALITY.—Upper Cambrian: (78 and 78s) ‘‘ St. Croix sandstone” in quarry near St. Croix River,
im suburbs of Osceola, Polk County, and (98) ‘‘St. Croix sandstone” near Eau Claire, Eau Claire County; both in
Wisconsin.
LINGULELLA NANNO (Walcott).

i Plate XXIV, figures 1, la-d.

Obolus (Lingulella) nanno Watcortt, 1898, Proc. U. S. Nat. Mus., vol. 21, p. 409. (Described as below as a new

species.) ,

Shell very small; general form elongate ovate, with the ventral valve subacuminate to
acuminate, and the dorsal valve elongate in outlme. The convexity of the two valves is mod-
erate in the very small shells, increasing slightly with the increase in size. Average length of
the ventral valve is about 2 mm., and that of the dorsal valve a little less.

The surface of the shell as it appears in the hard, fine-grained, drab-colored limestone is
marked by fine, concentric striz, and very faint traces of radiating striz.

Observations.—This minute species occurs in thin layers of limestone interbedded in the
Conasauga (“Coosa’’) shale. Its small size and acuminate ventral valve distinguish it from
other species. It is associated with Dicellomus appalachia Walcott and fragments of trilobites.

FoRMATION AND LOCALITY.—Middle Cambrian: (16) Conasauga limestone, Blowntsville Valley, Blount County;
and (91) Conasauga (“‘Coosa”’) shale at Cedar Bluff, Cherokee County; both in Alabama.

LINGULELLA NATHORSTI Linnarsson.

Plate XX XI, figures 1, la—h.

Lingulella ? nathorsti LinNarsson, 1876, Bihang till K. svensk. Vet.-Akad. Handl., Bd.3, No. 12, pp. 15-16, Pl. III,
figs. 24-30. (Described and discussed in English as a new species.) :

This is a medium-sized well-characterized species. As the illustrations of Linnarsson
[1876, Pl. IIT] are not altogether satisfactory I have had several drawings made from material
received from Dr. G. Lindstrém.

Plate XX XI, figures 1, la—b, represents specimens from the gray, arenaceous, shaly sand-
stones at Andrarum, and Plate XX XI, figures 1c-e, specimens from the hard, dark-gray sand-
stones in Dalarne. Specimens from the dark sandstone show the surface of the shell to have
been marked by concentric striz and lines of growth and very fine radiating striz. The casts
from the arenaceous shales show the area of the valves (Pl. XX XI, figs. 1 and 1b) and traces of
the vascular markings.

Observations —In form and outline Lingulella nathorsti may be compared with L. radula
Matthew, but it differs greatly from that species in its surface characters.

The specific name was given in honor of Mr. A. G. Nathorst.

FORMATION AND LOCALITY.—Lower Cambrian: (320x) In strata with Holmia kjerulfi at Andrarum, 20 miles (82

km.) northwest of Simrishamn, Province of Christianstad; and (8y) with Torellella cevigata in the ‘‘Sparagmite” sandstone,
at Skarésen, northwest Dalarne, Province of Kopparberg; both in Sweden.

‘a8 is the type locality.

522 CAMBRIAN BRACHIOPODA.

LINGULELLA NICHOLSONI Callaway.
Plate XXX, figures 3, 3a-f.

Lingulella nicholsoni CALLAWAY, 1874, Quart. Jour. Geol. Soc. London, vol. 30, p. 196. (Name proposed.)

Lingulella nicholsoni Cantaway, 1877, idem, vol. 33, pp. 668-669, Pl. XXIV, figs. 11, 1la-b. (Described and discussed
as below. Figs. 11 and 11b are reproduced in this monograph, Pl. XXX, figs. 3 and 3a, respectively.)

Lingulella nicholsoni Callaway, Davipson, 1883, British Fossil Brachiopoda, vol. 5, pt. 2, pp. 208-209, Pl. XVII, figs.
31, 3la, and 32. (The discussion of the species, the localities, and the figures given in the preceding reference
are here copied.)

Lingulella nicholsoni Callaway?, MatiEy, 1902, Quart. Jour. Geol. Soc. London, vol. 58, pt. 1, p. 141. (A new locality
mentioned.)

The original description by Callaway follows:

Ovate, depressed, widest about the middle, two-thirds as broad as long, front and sides rounded, beak moderately
acuminate, area of ventral valve striated, the striz parallel to the external slope of the valve, pedicle groove divided
by a narrow ridge down the middle; visceral surface pitted; exterior surface marked by fine concentric lines of growth.

Length, 5 lines; width, 3.5 lines.

- This is a larger shell than Lingulella ferruginea Salter and its sides are not so parallel.
It closely resembles L. lepis (Salter); but L. lepis is wider toward the front, according to
Davidson’s figures [1883, Pl. XVII, figs. 31, 31a, and 32].

In a collection kindly lent to me by Dr. Charles Lapworth I found this species to vary
greatly in outline in the shales. It is a well-marked species. Plate XXX, figures 3b and 3e,
shows probably the most characteristic adult forms.

The specific name was given in honor of Mr. Nicholson.

ForMATION AND LOCALITY.—Upper Cambrian: (304i [Callaway, 1877, p. 669]) Shineton shales at Shineton, Mary
Dingle, Dryton, Cressage, 1 mile (1.6 km.) west of Cressage, west of Harley, and under Cound- Moor quarry; and (804k
[Davidson, 1883, pp. 208 and 209]) Shineton shales at Bull Hill Cottage and Pewardine; all in South Shropshire,
England.

(3041) In the collection received from Dr. Charles Lapworth, collected by R. R. Rhodes, of the Geological
Survey of Great Britain, the species is recorded in shales at the following localities: 2246, 2481, 2499, 2512, 2513,
2541, 2548, 2556, 2567, 2625, and 2627, all on Shineton Brook and vicinity, South Shropshire, England.

(304a [Groom, 1902, p. 110]) ‘‘Bronsil shales;” and (304b [Groom, 1902, p. 109]) lower part of the ‘“‘White Leaved
Oak shales” (the zone of Polyphyma); both in the Malvern Hills, between Herefordshire and Worcestershire, England.

/ LINGULELLA oRA (Walcott).
Plate XX XV, figures 9, 9a-d.

Obolus (Lingulella) orus Watcorr, 1905, Proc. U. 8. Nat. Mus., vol. 28, p. 330. (Characterized as below as a new
species. )

This is a shell of the Lingulella manticula (White) form, but differs from it in being more
elongate; ventral valve more acuminate and dorsal valve proportionately larger. Its nearest
allies in form are among the group of narrow, elongate shells occurring in New Brunswick
and Cape Breton. It differs from all of them—Lingulella collicia Matthew), L. flumenis (Mat-
thew), L. cania (Walcott), etc.—in having a thick, strong shell and usually more acuminate
dorsal valve. The exterior surface bears rather strong concentric lines of growth and very
fine, irregular, undulating, elevated strie that suggest the surface of Obolus (Westoma) ella
(Hall and Whitfield) when seen in reflected light with a strong magnifier.

This little shell occurs abundantly, but good interiors have not been found. The main
vascular sinuses appear to be submarginal in both valves, and the visceral area of the dorsal
valve narrow, extending a little beyond the center of the valve.

®

FORMATION AND LOCALITY.—Upper Cambrian: (9p) About 160 feet: (48.8 m.) above the porphyry contact wn the
limestones of the Reagan sandstone, in SE. + NE. } sec. 2, T. 4 N., R. 13 W; and (9q) about 10 feet (3 m.) above
the porphyry contact and 90 feet (27.4 m.) below the Arbuckle limestone, in limestones of the Reagan sandstone,
in middle of west half of sec. 2, T.4.N., R. 13 W.; both about 15 miles (24.2 km.) northwest of Fort Sill, Comanche
County, Oklahoma.

SGT

OBOLIDA. 523

A single specimen of a ventral vatve 4 mm. in length that is much like the corresponding
valve of Lingulella ora occurs at the following locality. More and better material is needed
before an identification can be made that is more than tentative.

Middle Cambrian: (11m) Drill cores of limestone in the Bonneterre limestone at horizons 10 and 20 feet (3 and
6 m.) above the Lamotte sandstone at Flat River, St. Francois County, Missouri.

LINGULELLA OWENI (Walcott).

u

Plate XVIII, figures 5, 5a-f.

Obolus (Lingulella) oweni Waxcort, 1898, Proc. U. S. Nat. Mus., vol. 21, p- 410. (Described and discussed essentially
as below as a new species.)

General form ovate, with the ventral valve obtusely acuminate, and the dorsal valve
more broadly rounded posteriorly; valves appear to have been moderately convex, as far as
can be determined from the flattened specimen in the shaly sandstones. Surface of shell
marked by concentric lines and strie of growth and indistinct, radiating strie. There are
no traces of the interior markings observed. The shell is of medium thickness; none of the
specimens show how it was built up, farther than that there were oblique lamelle attached to
the outer layer in the anterior portion of the valve. The largest ventral valve from Gibraltar
Bluff has a length of 16.5 mm.; width, about 12 mm.; an associated dorsal valve 14 mm. in
length, has a width of 11 mm. as it occurs flattened on the surface of the sandstone. A
smaller shell referred to this species from Osceola averages from 6 to 8 mm. in length.

As shown in the cast of an interior of a shell, the area is rather long, and divided midway
by a sharp pedicle furrow; the flexure lines are situated about midway between the cast of
the pedicle furrow and the lateral margin. The area formed a thin shelf between the pedicle
groove and the lateral margins, the undercut extending far back under the area; a broken
portion of this is preserved on the cast illustrated by figure 5a.

One cast of the interior of a ventral valve shows a slight trace of the visceral area (PI.
XVIII, fig. 5d). In a cast of a dorsal valve (fie. 5b) both the central and anterior lateral
muscle scars are somewhat indistinctly preserved.

Observations.—This species is most nearly related to Lingulella ampla (Owen). It differs,
as far as can be determined from the material for comparison, in being less elongate and in
the position of the central and anterior lateral muscle scars in the dorsal valve, as may be
seen by comparing Plate XVIII, figure 5b, with Plate XXVIII, figure 1g. The typical form
of this species is represented on Plate XVIII, figures 5, 5b, and 5c, and a smaller form, which
has been referred to it, by figures 5d, 5e, and Sf.

The species differs strongly from Obolus (Westonia) stoneanus (Whitfield) in its surface
markings, although the outline of the valves is almost the same in the two species.

The specific name was, given in honor of Dr. D. D. Owen.

FoRMATION AND LOCALITY.—Upper Cambrian: (78c) “St. Croix sandstone’’ at Osceola, Polk County; (86) “‘St.
Croix sandstone’’ at Van Ness’s quarry, Gibraltar Bluff, Lodi, Columbia County; (852) “‘St. Croix sandstone” at
Madison, Dane County; (85a) *‘St. Croix sandstone” at Brown’s quarry, Prairie du Sac, Sauk County; and (85s)

“St. Croix sandstone” at Prairie du Sac, Sauk County; all in Wisconsin.
(97) “‘St. Croix sandstone” at Reads Landing, foot of Lake Pepin, Wabasha County, Minnesota.

LINGULELLA PERATTENUATA (Whitfield).
Plate X XI, figures 1, la.

Lingulepis perattenuatus WarIrrieLD, 1877, U. 8. Geog. and Geol. Survey Rocky Mtn. Region, Rept. Geol. Black Hills
of Dakota, Prelim. Rept., p.9. (Described and discussed as on p. 524 as a new species.)

Lingulepis perattenuatus Wurrriep, 1880, U. S. Geog. and Geol. Survey Rocky Mtn. Region, Rept. Geol. and Re-
sources Black Hills of Dakota, by Newton and Jenney, p. 337, Pl. II, figs. 7-9. (Copy of preceding refer-
ence. The specimens represented by figures 7, 8, and 9 are redrawn in this monograph, Pl. XX1, figs. li, 1h,
and 1b, respectively.)

524 CAMBRIAN BRACHIOPODA.

Lingulepis cuneolus ScuucHERT (in part) [not WurrrieLp], 1897, Bull. U. S. Geol. Survey No. 87, p. 259. (Merely
refers Whitfield’s Lingulepis perattenuatus to L. cuneolus.)

Obolus (Lingulella) perattenuatus (Whitfield), Watcorr, 1899, Mon. U. 8. Geol. Survey, vol. 32, pt. 2, p. 443. (Merely
changes generic reference.)

The original description by Whitfield follows:

Shell spatulate or elongate-ovate, becoming acutely pointed toward the beak; sides below the middle of the
lencth of the ventral valve rounded; front margin very regularly curved; cardinal slopes straight, or sometimes slightly
convex; greatest width a little more than half the length of the ventral valve and sometimes nearly two-thirds as great.
Surface of the ventral valve depressed convex, very slightly subangular along the middle above the lower third of
the length, and a little more distinctly so in the upper part. Apex scarcely truncate. Dorsal valve considerably

’ shorter than the ventral, broadly truncated at the upper end, the line of truncation being distinctly arched. Surface
evenly convex. Structure of the surface of the shell polished, with fine, somewhat lamellose lines of growth.

The material studied by Whitfield, now in the collections of the United States National
Museum, has been carefully worked over and the cardinal area of both valves developed in
the casts of the interior of the shell (Pl. X XI, figs. 1 and 1d). The plane of the area of the
ventral valve coincides near its edges with the edge of the shell, but it rises quite rapidly toward
the pedicle furrow. It is divided at the center by a rather deep, strongly marked pedicle
furrow and near the lateral margin by a rather sharp, very narrow flexure line (Pl. X XI, figs.
la and 1c). The striz of growth cross the area parallel with its base. They are sharp and
crowded on the lateral slopes, but are very indistinctly preserved in the pedicle groove. The
area of the dorsal valve is lower than that of the ventral and, in the typical specimens, shows
nothing more than the fine striz of growth (Pl. X XI, fig. 11).

No traces of muscle scars or vascular markings have been found in the material from the
type locality in the Black Hills, but, in some casts of the interiors of valves from Texas, traces
of the visceral cavity and muscle scars are shown. In Plate XXI, figure le, the outline of the
visceral cavity (v) is preserved, also the main vascular sinus (vs). :

Both valves of the shell are much thinner than in Lingulella acutangula (Roemer). The
shell is formed of a thin outer layer and one or two inner layers or lamelle, which occur in the
posterior half of the shell. The surface of the outer layer is marked by concentric strie and
lines of growth and very fine, more or less interrupted radiating striz. The inner layer is
characterized on its outer surface by fine, concentric, radiating striez. A few minute puncte
occur on the inner surface of several shells, as shown by the papille on the cast.

Observations —The most nearly related species in the American Cambrian rocks is L.
acutangula (Roemer). It differs in having a much thinner shell, and, as far as they are pre-
served, in the character and position of the interior markings and muscle scars.

The type species was described from the ‘‘Potsdam formation” of the Black Hills. From
a recent study of the Black Hills Cambrian section I have found that it is from the Middle
Cambrian sandstones and limestones as they occur near the headwaters of Red Canyon Creek
and in the vicinity of Deadwood. It is also identified from the Middle Cambrian of central
Texas and in the same fauna from the ‘“‘ Tonto” sandstone of the Grand Canyon of the Colorado,
Arizona. In the Black Hills it is associated with Lingulella (Lingulepis) acuminata (Conrad)
and Dicellomus politus (Hall).

ForMATION AND LOCALITY.—Upper Cambrian: (67c) Sandstone on Tatur Hill, 7 miles (11.2 km.) northwest of
- Burnet, Burnet County; (70) limestone near Morgans Creek, Burnet County; and (68y) interbedded sandstone and
limestone on Packsaddle Mountain, Llano County; all in Texas.

Middle Cambrian: (355) Sandstones on Red Canyon Creek, southwest side of Black Hills; and (365f) sandstones near
Deadwood, Black Hills; both in South Dakota.

(74) Sandstone about 300 feet (91.4 m.) above the base of the Tonto group, at the head of Nunkoweap Valley;
and (74d) sandstone beds in the ‘‘Tonto’’ shale just above massive sandstones near the mouth of Bass Canyon, on the
south side of the Grand Canyon of the Colorado, southeast of Powells Plateau; both in the Grand Canyon of the Colo-
rado, Arizona.

A single ventral valve of this species, or a closely related form, occurs in the following
locality:

Middle Cambrian: (90) Siliceous limestone about 15 feet (4.6 m.) above the Coronado quartzite [Lindgren, 1905,

p- 3], 0.5 mile (0.8 km.) southwest of Milk ranch, on the first spur north of the one which the main road follows, Clifton
quadrangle (U. S. Geol. Survey), Graham County, Arizona.

OBOLIDZ. 525

LINGULELLA PHAON (Walcott).
Plate XXVI, figures 1, la-e.

Obolus (Lingulella) phaon Watcotr, 1898, Proc. U. 8. Nat. Mus., vol. 21, pp. 410-411. (Described and discussed
essentially as below as a new species. )

General form ovate, with the ventral valve subacuminate, and the dorsal broadly ovate;
valves of moderate convexity. Surface ot the shell marked by fine concentric lines and striz
of growth, and very fine more or less interrupted radiating striz; when the outer layer is exfo-
liated the inner surface is marked by numerous fine radiating strie; the interior surface as seen
in casts is more or less marked by rather large papille arranged in concentric lines, the papille
corresponding to the pits or puncte on the inner surface of the shell. The shell is rather thick,
and is built up of a thin outer layer and several mner layers or lamelle, the lamellae toward
the front being oblique to the outer layer. A large ventral valve 15 mm. in length has a width
of 13 mm.; a dorsal valve 11 mm. long has a width of 10 mm.

As shown in the cast of the interior of the shell, the area of the ventral valve rises gradu-
ally from the margin toward the pedicle groove. It is broken midway by the cast of a strong
pedicle furrow and a little more than halfway up toward the lateral margin by a strong flexure
line; the strize of growth are very fine and cross the area parallel with its base. The cast of the
undercut shows that the area formed a thin shelf between the pedicle groove and the lateral
margins. The area of the dorsal valve is well defined. As in the ventral valve the area
formed a thin shelf, as shown by the cast of the undercut extending well over the area in
several of the specimens; the cast of the broken edges of the undercut between the areas is
shown by Plate XXVI, figures 1b, 1e, 1d.

The cast of the interior of the ventral valve (Pl. X- XVI, figs. 1b and 1c) shows the strongly
defined, narrow, visceral area (v), the trapezoidal area (c) in which the central, middle, and
outside lateral muscle scars occur, also the anterior lateral muscle scars (j), and unusually
strong main vascular sinuses (vs). In a specimen which is not illustrated, apparent lines of
growth occur on the ridge in front of the trapezoidal area (c), a feature that is present in L.
hayesi (Walcott) and Obolus matinalis (Hall). In a dorsal valve the relatively narrow central
vascular area extends forward nearly to the center of the shell (Pl. X XVI, fig. 1d); central (h)
and anterior lateral (j) scars are faintly imdicated, also transmedian (i) scars, and the median
septum (s); the main vascular sinuses (vs) are unusually deep and well defined.

Observations.—This species at first inspection might be taken for Lingulella ampla (Owen)
(Pl. XXVIII). It occurs at the same horizon in association with Dicellomus politus (Hall).
It differs in having a broader and less elongate shell, with the visceral area of the dorsal
valve terminating near the center instead of forward of the center, and, as far as can be deter-
mined from the material at hand, in having a thicker shell. It also averages about one-fourth
less Im size.

FORMATION AND LOCALITY.—Upper Cambrian: (98 and 98x) ‘St. Croix sandstone’’ near Eau Claire, Eau Claire
County; and (82a) “‘St. Croix sandstone’’ 25 feet (7.6 m.) above the water level near the Knapp, Stout and Company’s

buildings, Menomonie, Dunn County; both in Wisconsin.
(84a) “St. Croix sandstone”’ at River Junction, Houston County, 20 miles (32.2 km.) below Dresbach, Minnesota.

LINGULELLA POGONIPENSIS (Walcott).

y,

Plate XX, figures 3, 3a-c.

Obolus (Lingulella) pogonipensis Watcorr, 1898, Proc. U. 8. Nat. Mus., vol. 21, pp. 411-412. (Described and dis-
cussed as below as a new species.)

Shell rather large, general form ovate, almost ovate cuneate in the ventral valve; dorsal
valve more ovate. Valves moderately convex. Surface of the shell marked by numerous
concentric lines and striz of growth, and very fine radiating strie; the finer concentric striz
are slightly irregular, but not nearly so much so as in many species of the genus. The outer

a 98x is the type locality.

526 CAMBRIAN BRACHIOPODA.

surface of the inner layer is marked by very fine radiating striz, also concentric lines of growth.
The shell is below the average thickness and is formed of a thin outer layer and one or more
inner layers or lamelle.

The largest ventral valve has a length of 15 mm.; width, 11 mm. As shown by a partial
cast the area is of medium length, and divided midway by a narrow, strongly marked cast of
the pedicle furrow.

Observations—In form the valves of this species somewhat resemble those of Lingulella
ampla (Owen) (Pl. XXVIII), and more closely those of L. isse (Walcott) (Pl. XX XIX). In
the absence of all interior markings no further comparisons can be made.

The species derives its specific name from its occurrence in the Pogonip limestone.

FORMATION AND LOCALITY.—Passage beds between the Upper Cambrian and the Ordovician: (201) Arenaceous
Pogonip limestone, on east slope of ridge east of Hamburg Ridge; (205) siliceous limestone on Roundtop Mountain;
(208a) limestones at base of Pogonip limestone, in the spur on Hamburg Ridge extending out southwest from Wood
Cone; and (211) siliceous Pogonip limestone, on spur of Hamburg Ridge extending southwest from Wood Cone; all
in the Eureka district [Hague, 1892, Atlas], Eureka County, Nevada.

Specimens somewhat doubtfully referred to this species occur at the following localities:

Upper Cambrian: (32i) Thin-bedded siliceous limestones near the top of the Upper Cambrian, about 2 miles
(3.2 km.) southeast of Muskrat Spring, on the northwest face of Grantsville Peak, Stansbury Range, Tooele County,
Utah.

Upper? Cambrian: (358a) Siliceous limestone in Pinal County, Arizona.

' LINGULELLA PRIMA (Conrad MS.) (Hall).
Plate X XVII, figures 1, la-c.

Lingula ovata Emmons [not McCoy], 1842, Nat. Hist. New York, Geology, pt. 2, p. 105. (Mentioned.)

Lingula prima (Conrad MS.) Hatt, 1847, Nat. Hist. New York, Paleontology, vol. 1, p. 3, Pl. I, fig. 2. (Described
and discussed. It is the first description of the fossil, though no reference is made to the fact that it is a new
species. : 4

Fe. Sas am Emmons, 1855, American Geology, vol. 1, pt. 2, p. 202. (Described.)

Lingulepis prima (Hall), Miturr, 1877, American Paleozoic Fossils, Catalogue, p. 115. (Merely changes generic
reference.

Obolella prima aan WHITFIELD, 1884, Bull. Am. Mus. Nat. Hist., vol. 1, No. 5, pp. 142-143, Pl. XIV, figs. 3-5.
(Discussed. )

Liingulella? prima (Hall), Harn and CrarKe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, p. 69, footnote.
(Discussed. )

Lningulepis prima (Hall), ScxucneErr (in part), 1897, Bull. U. S. Geol. Survey No. 87, p. 260. (Merely changes generic
reference. Includes species other than Hall’s ‘“‘ Lingula prima.’’)

Obolus (Lingulepis) primus (Hall), Wancorr, 1901, Proc. U. 8. Nat. Mus., vol. 23, p. 673. (Merely changes generic
reference. )

General form subovate with the ventral valve subacuminate and the dorsal valve broadly
subacuminate. There is a tendency in some individuals to a subcuneate outline. Valves
moderately convex, mcreasing in some shells to almost strongly convex. There is some range
of variation in the outlines of the valves, as shown by Plate X XVII, figures 1 and la. The
surface of the shell is marked by concentric lines and small undulations of growth and by very
fine radiating striz. When the outer layer is exfoliated the inner layer is seen to be marked
by sharp radiatmeg striz and a few concentric lines of growth. The interior surface shows
fine radiating strie and a few scattered pits. The shell is of medium thickness and formed
of a thin outer layer and several inner layers, or lamelle, which are more or less oblique to the
outer layer; the lamella are much more numerous toward the margins and form a rather thick
rim around the anterior and anterolateral margms. The average length of the ventral valve
is 5 mm., width 4 mm. The dorsal valve is slightly shorter in proportion to its width.

As shown in the interior casts the area of the ventral valve is relatively short; it is divided
at the center by a rather strongly marked pedicle furrow and well out toward its margins by
clearly defined flexure lines. Faint traces of strie of growth cross the area parallel with its
base; the area of the dorsal is not shown in any of the specimens in the collection.

The cast of the interior of the ventral valve shows the visceral cavity (v), the trapezoidal
area (c), ana the rather strong median ridge, which extends from the area forward to the anterior

OBOLIDZ. 527

‘margin of the visceral area. This ridge corresponds to a median groove passing anteriorly
into the heart-shaped cavity. There are no clearly defined muscle scars nm any specimen in
the collection, although the trapezoidal area in the ventral valve, in which the central, middle,
and outside lateral muscle scars usually occur, is fairly well preserved in one specimen. None
of the casts of the dorsal valve show more than the cast of the median ridge or septum. Of
the markings left on the shell by the vascular system only the main vascular sinuses have
been preserved on the cast of the ventral valve.

Observations —This is a small but striking species that occurs in the sandstones east of
the Adirondack Mountains. In outline and form it may be grouped with Lingulella ferruginea
Salter and Z. bellula (Walcott) (P!. XIX). It is a larger and more acuminate shell than
L. ferruginea, and its dorsal valve is distinguished from that of LZ. bellula by being shorter
and broader anteriorly. It occurs quite abundantly in the thm beds of hard sandstones at
Ausable Chasm, below Keeseville, Essex County, New York, associated with Piychoparia minuta
and L. (Lingulepis) acuminata (Conrad)(?). The interior of the ventral valve resembles typical
forms of Obolus more nearly than the typical forms of Lingulella. This may be’due to the state
of preservation or it may be that, despite the Lingula-like outlines of the valves, it is more a
true Obolus in its interior markings as these are developed in O. matinalis (Hall). (Compare
Pl. VIII, fig. le, with Pl. XX VII, fig. 1.)

Whitfield [1884, p. 142] referred the species to the genus Obolella. There is a strong
resemblance between the dorsal valve of the species and that of some of the species of Obolella,
but a careful study of a large amount of material shows that this resemblance is confined to
the dorsal valve. He also refers ‘“‘Obolella mitida” Ford to this species, but “O. nitida” is a
true Acrotreta and occurs in the lower portion of the Olenellus fauna of the Lower Cambrian,
and Lingulella prima (Hall) is from the Upper Cambrian.

Dwight [1886, p. 208] mentions ‘‘Obolella (Lingulella) prima” as occurring in ‘‘ Potsdam”
strata at Poughkeepsie, New York, but inasmuch as he does not describe the specimen, and
the form has not been found in other extensive collections that have been made there, the
reference is considered as exceedingly doubtful. I thmk Dwight had small specimens of the
dorsal valve of Lingulella (Lingulepis) acuminata (Conrad), which occurs at the locality at.
Poughkeepsie.

FORMATION AND LOCALITY.—Upper Cambrian: (77)% Sandstone near the water below the falls at the high bridge,
and also at several horizons in the section, the highest point being 70 to 75 feet (21 to 23 m.) above the water, in Ausable
Chasm; (367{) sandstone at French Creek, 1 mile (1.6 km.) east of Keeseville; (367g) sandstone in the bed of the
brook, in the suburbs of Port Henry; (367h) Rosses Bridge, 4 miles (6.4 km.) west of Essex; (136) Potsdam sandstone

in bank of stream opposite the first switch on the Port Henry and Maine Railroad out of Port Henry; and (338t’
Potsdam sandstone in Ausable Chasm, below Keeseville; allin Essex County, New York.

eS LINGULELLA? Primmva Hicks.

Plate XX XI, figures 5, 5a.

Lingulella primeva Hicks, 1871, Quart. Jour. Geol. Soc. London, vol. 27, p. 401, Pl. XV, figs. 13 and 14. (Described
as a new species. )

Lingulella primxva Hicks, Saurer and Erneripee, 1881, Mem. Geol. Survey Great Britain, vol. 3, 2d ed., p. 538.
(Localities mentioned.)

Lingulella primxva Hicxs, 1881, Popular Science Review, new ser., vol. 5, p. 297. (Mentioned only.)

Lingulella primxva Hicks, Davipson, 1883, British Fossil Brachiopoda, vol. 5, pt. 2, p. 208, Pl. XVII, figs. 33 and
34. (Described and discussed. Fig. 33 is drawn from the specimen figured by Hicks, 1871, Pl. XV, fig. 14.
Figs. 33 and 34 are reproduced in this monograph, Pl. XX XT, figs. 5a and 5, respectively.)

This species is rather doubtful, owing to its condition of preservation, which renders it
quite difficult to make any comparison with other described species. It occurs in association
with LZ. ferruginea Salter, but is a much larger species.

FoRMATION AND LOCALITY.—Middle? Cambrian: (366c) ‘‘Caerfai growp’’ [Salter and Etheridge, 1881, p. 538] at

Caerfar, Nuns Ehll, and Porthclais Harbor, all south of St. Davids; and (818i) red shales of the Caerfai group at St.
Dayids; both in South Wales.

a77 is the type locality, though the specimens in the United States National Museum collections to which that number is assigned
were collected later than the type specimens.

528 CAMBRIAN BRACHIOPODA.

LINGULELLA PUNCTATA (Walcott).

Plate XX, figures 6, 6a.

Lingula? manticula Watcorr [not Wurre], 1884, Mon. U. 8. Geol. Survey, vol. 8, pp. 15-14, Pl. LX, fig. 3, and Pl.
XI, fig. 2. (Discussed. The specimens represented by Pl. IX, fig. 3, and Pl. XI, fig. 2, are redrawn in this
monograph, Pl. XX, figs. 6 and 6a, respectively.)

Obolus (Lingulella) punctatus WaucotT, 1898, Proc. U. S. Nat. Mus., vol. 21, pp. 412-413. (Described as below as a
new species. )

General form ovate, with the ventral valve subacuminate. Valves moderately convex,
with the dorsal valve having a slightly depressed median sinus that extends from near the
umbo to the anterior margin. Surface of shell marked by lines and striz of growth, and very
fine, slightly undulating strie; also a few faintly indicated radiating striz; when the outer
layer is exfoliated the outer surface of the inner layer is seen to be marked by numerous and
very fine radiating strie, im addition to the concentric lmes of growth; the interior of the
shell, as shown a the casts, was strongly pitted or punctate, the puncte being arranged in
concentric lines following the lines of growth. The shell is relatively thin smal fommad of a
thin outer layer and one or more thin inner layers or lamelle.

The type specimen of the ventral valve has a length cf 9 mm., width 6.5 mm. An asso-
- ciated dorsal valve has a length of 7 mm., width 5.5 mm.

The only interior that shows anything more than the punctate surface is that of the dorsal
valve. In this the area is partly shown; it is relatively short and marked by fine striz par-
allel to its base, and two imperfectly developed flexure lines. The cast of a narrow median
septum is well shown, and on each side of it the middle lateral muscle scars. The path of
advance of the central muscle scars is quite plain, also one of the scars. The only trace of
the vascular system is a portion of a main vascular sinus.

This form owes its specific name to the concentrically punctate interior of the shell.

FoRMATION AND LOCALITY.—Upper Cambrian: (8f) Limestone at summit of canyon, 10 miles (16.1 km.) south
of Egan Canyon, east side of Egan Range, White Pine County; (80) limestone on the slope of the ridge where the range
swings around to the northwest, 2 miles (3.2 km.) north of Aurum, Schell Creek Range, White Pine County; (61)
limestone in the Dunderberg shale [Walcott, 1908f, p. 184], a little south of the Hamburg mine, Eureka district
[Hague, 1892, Atlas], Eureka County; and (62) limestone in the Dunderberg shale [Walcott, 1908f, p. 184], in canyon
immediately north of Adams Hill, Eureka district [Hague, 1892, Atlas], Eureka County; all in Nevada.

Middle Cambrian: (7i) Limestone just west of the summit on the road east of Schellbourne, Schell Creek Range,
White Pine County, Nevada.

(54) Eldorado limestone [Walcott, 1908f, p. 184], on east slope of Prospect Mountain, in New York Canyon;
(57) shaly limestone in the Eldorado limestone [Walcott, 1908f, p. 184], at the 700-foot (213.4 m.) level in the Rich-
mond mine, Ruby Hill [Hague, 1892, p. 48, and Pl. I, opposite p. 116]; and (58) shaly limestone in upper beds of
Secret Canyon shale, east side of New York and Secret canyons; allin the Eureka district [Hague, 1892, Atlas], Eureka
County, Nevada.

LINGULELLA QUADRILATERALIS (Walcott).

Plate XX XIX, figures 6, 6a.

Obolus (Lingulella) quadrilateralis Waucort, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 331. (Described and discussed

as below as a new species.)

General form rounded, quadrilateral; valves moderately convex. Surface marked by con-
centric lines and ridges of growth with fine strie between. The surface of the inner layers
of the shell is shiny and marked by fine radiating striz in addition to the concentric lines.
The shell is rather thin; it is built up of several layers.

Observations.—This species differs from other described species by its subquadrilateral
outline. In this respect it may be compared with Obolus ( Westonia) chuarensis (Walcott) (PI.
XXY), from which it differs in having a thinner shell and different surface markings.

FoRMATION AND LOCALITY.—Middle Cambrian: (91) Conasauga (‘‘Coosa”) shale, at Cedar Bluff, Cherokee County;
and (56q) limestone at the very top of the Conasauga limestone, in quarry at Ketona, about 5 miles (8 km.) northeast
of Birmingham, Jefferson County; both in Alabama.

(140a) Shales 200 yards (182.9 m.) east of Thomas Mills, 5-miles (8 km.) north of Cave Spring, Floyd County,
Georgia.

—

‘ OBOLIDA. o29

LINGULELLA RADULA Matthew.
Plate, XLV, figures 1, la—l.

Lingulella radula Matruew, 1891, Trans. Roy. Soc. Canada, Ist ser., vol. 8, sec. 4, No. 6, pp. 147-148, Pl. XV, figs.
7a-b and 8a-e. (Described and discussed as a new species. Pl. XLV, figs. 1, la, 1b, lc, and le, are drawn
from specimens in Matthew’s type material, but further identification is impossible.)

' Lingulella radula aspera Matrunw, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, pp. 204-205,

Pl. XV, figs. 2a-d. (Described and discussed as a new variety.)

General form ovate cuneate, with the ventral valve subacuminate and the dorsal valve
broadly ovate in outline; valves apparently moderately convex, but this is uncertain, as the
shells have all been compressed in the arenaceous shale. Surface marked by concentric lines
of growth and very fine, irregular stria. It is the type of surface of Obolus (Westonia) ella
(Hall and Whitfield) or Lingulella (Lingulepis) gregwa (Matthew), reduced so that the surface,
under a strong magnifier, has a roughened or minutely papillose appearance. Matthew [1891,
p. 148] describes it as due to wavy squamose ridgelets having the edges and points directed
forward, as in Botsfordia pulchra (Matthew). Owing to this roughened surface the outer layer
of the shell usually adheres to the matrix, leaving the dark, shiny surface of the inner layer.
The inner surface is marked by concentric rows of puncte and fine radiating strie. The
shell is of medium thickness and formed of a thin outer layer and several inner layers or lameHe,
which are more or less oblique to the outer layer on the anterior half of the shell, One of the
largest ventral valves has a length of 10 mm., width 8 mm.; a large dorsal valve has a length
of 9 mm., width 8 mm. :

The cardinal area and pedicle groove are usually obscured by the adhering fragments of
shell. The pedicle groove is strong and narrows gradually as it crosses the long area of the
ventral valve. The area of the dorsal valve is short and broad.

The cast of the visceral cavity (v) is preserved in a number of specimens. In Plate XLV,
figures 1 and 1i, the heart-shaped pit (x), so characteristic of Obolus and of Lingulella acutangula
(Roemer), is clearly outlmed. A narrow median septum (s) is found in the dorsal valve (PI.
XLV, figs. 1j and 11), and the anterior lateral muscle scars (j, fig. 11) are clearly shown in the
ventral valve. The centrals, middle laterals, and outside laterals can not be differentiated in
the trapezoidal area (c) in front of the heart-shaped pit. On the dorsal valve the centrals (h,
figs. 1d, 1j, and 11) and anterior laterals (j, fig. 1}) are finely preserved.

Considerable portions of the markings of the vascular system are preserved on the casts
of the interior of the valves. The main vascular trunks of the ventral valve are shown by
figures 1, la, and 1c, and the position of the parietal scar is also seen at ps (figs. la, 1c, and 1i).

Observations.—Doctor Matthew sent me the types of this species for study and illustration.
I have not been able to interpret some of the interior markings in the manner that his figures
indicate, but this is not unexpected when the obscure character of most of the specimens is
considered. When at St. John, in 1877, I collected a large number of specimens of this species,
and, as they are somewhat better preserved than the types, drawings have been made of the
casts of the interiors of three ventral valves and one dorsal valve.

The variety, spoken of by Matthew [1903, p. 204], from the lower portion of Division 2c
shows the outer surface unusually well preserved, but I do not think it is a distimct species
or worthy of a varietal name. In the collections made by Loper on McPhees Brook, Division
2 of Matthew’s section, there are small specimens that correspond to Matthew’s variety aspera
collected on McNeil Brook; also adult specimens. The horizon is much lower, according to
Matthew’s sections, but the specimens are very much alike from the two localities.

FoRMATION AND LOCALITY.—Middle Cambrian: (30ly) Shaly sandstones of Division C2c of Matthew, east side of

Courtney Bay, St. John; and (801x) sandstones of Division C2c of Matthew, in the city of St. John; both [Matthew,
1891, p. 148] in New Brunswick.

(307c [Matthew, 1903, p. 205]) Sandstones probably belonging with Division C2c of Matthew, on Mira River; and
(307b) sandstone on McPhees Brook; both in eastern Cape Breton, Nova Scotia, Canada.

62667°—vo1 51, pr 1—12——34

530 CAMBRIAN BRACHIOPODA.

LINGULELLA RANDOMENSIS (Walcott).
Plate X- XJ, figures 5, 5a.

Obolus (Lingulella) randomensis Waucort, 1901, Proc. U.S. Nat. Mus., vol. 23, pp. 688-689. (Described and discussed
as below as a new species.)

General form elongate ovate; ventral valve rather broadly subacuminate, and the dorsal
valve slightly acuminate. The widest portion of the valves is the anterior third, from which
they very gradually narrow toward the cardinal slopes. The convexity of the valves is mod-
erate and uniform and nearly the same in each. Surface of the shell marked by fine concentric
strie, and rather strong lines of growth, also fine radiating strie. The shell is formed of a few
thin lamelle or layers, as far as can be determined from the fragments preserved on the casts
in the sandstone. The longest ventral valve in the collection has a length of 10 mm. with a
maximum width of 6 mm. The dorsal valve is slightly shorter.

As shown by the interior cast the area of the ventral valve is rather long, and extends
well forward on the cardinal slopes. It is divided at the center by a narrow pedicle furrow
and midway by a very slight flexure line. The base of the area curves backward over the
margin, arching slightly forward before reaching a rather deep indentation at the center. The
strie of growth cross the area parallel to its base. They are very sharp and fine and quite
uniformly distributed over the area. Area of the dorsal valve unknown.

Observations.—This pretty species occurs in great numbers in thin layers of brown sand-
stone embedded in a dark shale a short distance below the Olenus zone. In form it resembles
Lingulella mosia osceola (Walcott) (Pl. XVIII, figs. 2 and 2c). It differs from it in having a
narrower pedicle furrow and, when comparing a large number of specimens, in being slightly
more elongate. It is proportionately narrower toward the beak.

The species derives its specific name from its occurrence on Random Island.

ForMATION AND LOCALITY.—Upper Cambrian: (6y) Sandstone on north side of Random Island, between Birch
and Sandy points, Smith Sound, Trinity Bay, Newfoundland.

LINGULELLA ROTUNDA (Matthew).
Plate XX XVII, figures 3h-k.

Lingulepis rotunda MattHEWw, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, p. 199, Pl. XIV,
figs. 4a-f. (Described and discussed as a new species.)

This small species is marked by its nearly circular, convex dorsal valve. The inner
surface of the shell is strongly punctate, but I could not find the minute tubercles on the
outer surface of the dorsal valve described by Matthew. ‘The outer surface, where preserved,
appears to be smooth or marked by concentric striz.

FoRMATION AND LOCALITY.—Middle Cambrian: (325a [ Matthew, 1903, p. 199]) Shales of Division C2c of Matthew's
[1908, p. 49] Bretonian, on the eastern slope of the valley of McNeil Brook, on the road to Trout Brook, in the Mira River
valley; (3i) in compact, fine-grained, thin-bedded, gray sandstone, of the Paradoxides zone, on McLean Brook, 1 mile

(1.6 km.) east of McCodrum Brook, and 1.5 miles (2.4 km.) west of Marion Bridge; and (825c) sandstone on the shore
of Bras d’Or Lake; all in eastern Cape Breton, Nova Scotia, Canada.

LINGULELLA SCHUCHERTI (Walcott).
Plate XX1I, figure 6.

Obolus (Lingulella) schucherti WatcotT, 1901, Proc. U. S. Nat. Mus., vol. 28, pp. 689-690. (Described and discussed
as below as a new species.)

General form elongate ovate, ventral valve subacuminate and the dorsal valve elongate
ovate in outline. Surface marked by fine concentric striz, and rather strong concentric undu-
lations or lines of growth; also fine radiating striz, and on some specimens indistinct, radiating,
rather narrow, depressed furrows.

Pee rele Gre! © A

OBOLID. ddl

The outer surface of the inner layers shows radiating striz and concentric lines of growth.
The radiating striz are also present on the inner surface outside of the area of the vascular
cavity.

The shell is thick and formed of a thin outer layer and several thin inner layers or lamellz
arranged very much as in other shells of the genus Lingulella. The largest ventral valve has
a length of about 11 mm.; width, 7 mm. A dorsal valve 8 mm. in length has a width of
5.5 mm.

Casts of the interior of the ventral valve show a well-marked area, with a broad, strong
pedicle furrow. The base of the area arches strongly forward. Just at the center, across the
pedicle furrow, however, it has a slight backward arch. None. of the specimens show the
flexure line or the extent of the area along the cardinal slopes of the valve. The area of the
dorsal valve is unknown. None of the characters of the visceral cavity or vascular markings
are shown with sufficient clearness to describe them. A tubercle on each side of the median
line, just in advance of the area, indicates the main vascular sinus, and a depression the position
of the anterior portion of the visceral cavity.

Observations —This is probably the oldest species of the genus Lingulella. Tt is associated
with Botsfordia celata (Hall), Elluptocephala asaphoides Emmons, and other characteristic
species of the Lower Cambrian. In its elongate dorsal valve it recalls Obolus rhea Walcott
of the Middle Cambrian (Pl. IX, figs. 1, la—c). It differs from that species in the character of
the shell and the outline of the valve.

The specific name is given in honor of Prof. Charles Schuchert, who collected the only speci-
men of the species known to me.

ForMATION AND LOCALITY.—Lower Cambrian: (367) Conglomerate and limestone, Troy, Rensselaer County,
New York.

5 LINGULELLA SIEMIRADZKII (Walcott),
: Plate XX XI, figures 2, 2a.
Lingula sp. cf. ecunguis Hichwald, Stemrrapzx1, 1886, Jahrb. K.-k. geol. Reichsanstalt for 1886, Bd. 36, Hit. 4,

p- 672. (Mentioned in German.)

Lingula ci. erunguis Eichwald, Giricn, 1892, Neues Jahrb. fiir Mineralogie, Bd. 1, p. 69. (Mentioned in German.)
Lingula sp. Lingula aff. ecungui Eichwald, Gtricu, 1896, Verhandl. Russ.-kais. min. Gesell. St. Petersburg, 2d ser.,

Bd. 32, p. 214. (Discussed.)

Obolus (Lingulella) siemiradzkit Waxcorr, 1901, Proc..U. S. Nat. Mus., vol. 23, pp. 690-691. (Discussed as below
as a new species.)

Attention was called to this species by Siemiradzki [1886, p. 672] in connection with his
study of the Paleozoic rocks of the Mittelgebirge of Poland. He speaks of it as ‘‘ Lingula sp.”
in the black conglomerate, and compares it with ‘‘Z. exunguis Hichwald.” In the associated
gray sandstone he found an Obolus which he says is identical with ‘‘O. silwricus Eichwald.”’

Giirich discusses the Cambrian of Sandomierz in a paper on the Paleozoic of the Mittel-
gebirge, and mentions [1896, p. 17] Siemiradzki’s discovery of fossils in the lower sandstones
and shales.

Girich added greatly to the fauna found by Doctor Siemiradzki. He mentions [1896,
p- 17] Paradoudes cf. tessim, P. bohemicus, Agnostus fallax, A. gibbus, and Liostracus linnars-
soni, and refers the fauna to the Middle Cambrian. The ‘‘ Lingula” he compares [1896, p. 214]
with ‘‘Lingula crassa Kichwald,” calling attention to the resemblance in the surface charac-
ters; also to those of Lingulella davisi (McCoy).

This is a small shell belonging to the group of species containing Lingulella ferruginea
Salter, L. desiderata (Walcott), etc. The outer surface is marked by concentric, slightly undu-
lating, and imbricating strize of growth, and the outer surface of the inner layers by fine radiat-
ing strie. The general form and other characters are represented in Plate XXXI, figures 2
and 2a.

Through the kindness of Dr. Fr. Schmidt I received a fragment of gray quartzitic sand-
stone containing a large number of specimens of the ‘‘Lingula’’ of Siemiradzki. The shell

532 CAMBRIAN BRACHIOPODA.

proves to be a true Lingulella. In the same piece of rock an obscure form of Obelus occurs
that may be a medium-sized Obolus apollinis Eichwald. I take pleasure in naming the Lin-
gulella after its discoverer, Dr. J. S. Siemiradzki.

ForRMATION AND LOCALITY.—Middle Cambrian: (368) Quartzitic sandstone in the Pepper Mountains, near
Sandomierz, on the Vistula, Russian Poland.

LINGULELLA ? sIGNATA (Barrande).

Plate XXX, figure 11.

Lingula ? signata BARRANDE, 1868, Faune silurienne des environs de Hof, en Bavieére, p. 103, fig. 73. (Described

and discussed in French as a new species. Fig. 73 is reproduced in this monograph, Pl. XXX, fig. 11.)
Lingula ? signata BARRANDE, 1868, Neues Jahrb. fiir Mineralogie for 1868, p. 692, unnumbered plate, fig. 73. (Copy

of preceding reference. )

This species is doubtfully referred to Lingula by its author. It is oval in outline, with
a strongly arched surface. Where the shell is partly removed two small, elongate impres-
sions are seen near what is supposed to be the posterior portion of the valve, and on the front
portion of the shell a longitudinal groove. Barrande [1868a, p. 103] remarks that the latter
recalls the perforation of Discuna; but it is not perforated, as the shell continues over the
entire surface of the depression. The aspect of the shell is horny and without ornamentation.
Length, 2.56 mm.; width, 2 mm.

It is very doubtful if this species should be referred to Lingulella, but it may possibly
be a rounded dorsal valve somewhat like that of LZ. mosia (Hall), LZ. ferruginea Salter, or Lingu-
lella (Lingulepis) acuminata (Conrad).

FORMATION AND LOCALITY.—Passage beds between the Upper Cambrian and the Ordovician: (308¢ [Barrande,
1868a, p. 103]) Suburbs of Hof, Bavaria, Germany.

LINGULELLA simiLis (Walcott).
Plate X XT, figures 2, 2a-j, 3, 3a-d.

Obolus (Lingulella) similis Watcorr, 1898, Proc. U. S. Nat. Mus., vol. 21, pp. 415-416. (Described and discussed
as below as a new species.)

Shell small, general form ovate, with the ventral valve subacuminate, and the dorsal
valve rounded ovate in outline. There is some variation in the outline of the valves; this
may be seen by comparing Plate X-XI, figures 2 and 2b, of the ventral valve, and figures 2a
and 2c of the dorsal valve. Surface of the shell marked by concentric lines of growth and
very fine, slightly irregular, concentric striz. Where the outer surface is well preserved, fine
radiating strie may be seen with a strong magnifying glass. When the outer layer of the
shell is exfoliated the outer surface of the inner layer is marked by fine concentric lmes and
very fine numerous radiating strie; the inner surface of the shell shows concentric lines of
growth and faint, scattered pits or puncte. The shell is of medium thickness and formed
of a thin outer layer, with one or more inner layers or lamellx. The latter are especially prom-
inent toward the front, where they have essentially the same arrangement as in Lingulella
acutangula (Roemer). The average length of the ventral valve is from 4 to 5 mm.; width,
2.5mm. An associated dorsal valve 4 mm. in length has a width of 3 mm.

A cast of the interior of a ventral valve shows a clearly defined area of medium length.
It is divided midway by a cast of a narrow, strong pedicle furrow, and on each side by flexure
lines situated about two-thirds the distance from the pedicle furrow to the lateral margin;
a few indistinct strie cross the area parallel with its base. The area of the dorsal valve as
seen in a cast is well defined and rather large; it is marked by fine, transverse striz of growth
and indistinct flexure lines. A cast of the interior of the dorsal valve shows a trace of the
visceral cavity and a narrow median septum. The only muscle scars observed are the two
umbonal scars in the ventral valve (¢), figure 2, and the central (h) and the anterior lateral
sears (j) of the dorsal valve, figure 2a.

OBOLIDA. 533

Observations.—This very pretty little species occurs in abundance in the compact gray
limestone of the Black Hills associated with numerous fragments of trilobites and Dicellomus
nanus (Meek and Hayden). The more elongate forms strongly resemble Lingulella peratten-
wata (Whitfield), which occurs in the Middle Cambrian sandstones on the southern margin
of the Black Hills. The species differs, however, from the latter in being more ovate and
in having the dorsal valve more obtusely rounded posteriorly. This species may be also com-
pared with ZL. desiderata (Walcott) and L. manticula (White). When flattened in the shales
it is difficult to distmguish it from L. desiderata.

A small shell occurs in the “St. Croix sandstone” of the upper Mississippi region that
appears to be identical with this species, both in its typical form and in its comparatively
wide range of variation. With the somewhat abundant supply of material from both the
Black Hills and Wisconsin, I am unable to determine any specific differences that are con-
stant. The same is true of the form in the limestones south-southwest of Potosi, Missouri,
where it is associated with Linnarssonella girtyt Walcott.

The same range of variation occurs in shells from the limestone in the upper part of the
Reagan sandstone of Oklahoma, and apparently they are identical.

In the shaly sandstones of the Rome formation in Tennessee casts of an apparently iden-
tical form occur (Pl. X XI, figs. 3, 3a-d). The variation between the Tennessee and South
Dakota shells does not appear to be greater than the range of variation among the shells from
the same locality in the Black Hills and the localities where it has been identified in Wisconsin
and Minnesota.

In a limestone at the north end of the Quinn Canyon Range, Nevada, J. E. Spurr, of the
United States Geological Survey, collected a number of small shells that appear to be identical
with this species. The shells are well preserved and have the general form of surface charac-
teristic of the species. A single specimen of a larger ventral valve has all the characteristics
of L. manticula (White).

A shell from Middle Cambrian limestones at Mount Nebo, Wasatch Range, Utah, is doubt-
fully referred to this species. It is associated with Micromitra (Iphidella) pannula (White)
and Acrotreta neboensis Walcott.

This form owes its specific name to its marked resemblance to several other forms, from
each of which, however, it is distinct.

FORMATION AND LOCALITY.—Upper Cambrian: (12m) Arbuckle limestone (in the section 7 miles (11.2 km.) north
of Springer this horizon is about 30 feet (9.1 m.) above the Reagan sandstone), in NE. } sec. 2, T.2S., R. 1 E., Ard-
more quadrangle (U. S. Geol. Survey), Carter County, Oklahoma.

(12n) Limestone of the Reagan sandstone (in the section 7 miles (11.27 km.) north of Springer this horizon is
about 240 feet (73 m.) above the porphyry contact and 40 feet (12 m.) below the Arbuckle limestone), NW. 4 sec. 1,
T.258., R. 1 E., Ardmore quadrangle (U. S. Geol. Survey), Carter County; (12k) limestone of the Reagan sand-
stone (in the section 7 miles (11.2 km.) north of Springer this horizon is about 225 feet (69 m.) above the porphyry
contact and 55 feet (17 m.) below the Arbuckle limestone), on the west side of Honey Creek, near the southeast corner
of sec. 35, T.18., R.1H., Ardmore quadrangle (U. S. Geol. Survey), Carter County; (12p) about 225 feet (69 m.)
above the igneous rocks in the limestone of the Reagan sandstone, at the northwest extremity of the Arbuckle Moun-
tains, about 4 miles (6.4 km.) east of Homer, Carter County; all in Oklahoma.

(9r) About 45 feet (14 m.) above the porphyry contact in the limestone of the Reagan sandstone, SE. + NE. +
sec. 2, T.4N., R. 13 W.; (9s) about 85 feet (26 m.) below the Arbuckle limestone in the limestone of the Reagan sand-
stone, middle of west half of sec. 13, T. 4 N., R. 13 W.; (9t) about 170 feet (52 m.) above the porphyry contact in the
limestone of the Reagan sandstone, SE. + NE. i sec. 2, T. 4N., R. 8 W.; aug Gy) about 195 feet (59.4 m.) above
the porphyry contact in the limestone of the Reagan sandstone, SE. 1 NE. + sec. 2, T. 4 N., R. 13 W.; all about 15.
miles (24.2 km.) northwest of Fort Sill, Comanche County, Obie,

(28a) “St. Croix sandstone” 4 miles (6.4 km.) north of Winfield; and (97a and 97c) “‘St. Croix sandstone”’
near Winfield; both in Jefferson County, Wisconsin.

(78b) “St. Croix sandstone”’ 50 feet (15.2 m.) above St. Croix River, near the ‘vedting at Osceola, Polk County;
(328n) “St. Croix sandstone” 2 miles (3.2 km.) south of Osceola, Polk County; and (80a) ‘‘St. Croix sandstone”?
4 miles (6.4 km.) north of Reedsburg, Sauk County; all in Wisconsin.

(86a) “St. Croix sandstone” near Redwing, Goodhue County; (839d) ‘‘St. Croix sandstone” at Taylors Falls,
Chisago County; (82c) conglomerate beds in the ‘‘St. Croix sandstone” in point below Franconia, Chisago County;

534 CAMBRIAN BRACHIOPODA.

(97s) “‘St. Croix sandstone” at Franconia, Chisago County; and (97) “St. Croix sandstone” at Reads Landing, foot of
Lake Pepin, Wabasha County; all in Minnesota.

Middle Cambrian: (7j) Limestones at the north end of the Quinn Canyon Range, 1 mile (1.6 km.) northwest of

the Italian Ranch foothills, Nye County, Nevada.

(360d) Siliceous limestones near Pike View, north of Colorado Springs, El Paso County, Colorado.

(355a) Shales in Bear Gulch Valley; (88a) limestone about 100 feet (30.5 m.) above the quartzitic sandstone at the
base of the Cambrian in the northern suburbs of Deadwood; (165) limestone on the east side of the valley, in railroad cut
about,1 mile (1.6 km.) below the main part of Deadwood; and (17j) limestone in the east end of the town of Galena;
all in the Black Hills, South Dakota.

(1le) Thin-bedded limestones south-southwest of Potosi, Washington County, Missouri.

(10a) Sandy layers of the Rome formation, in western railroad cut through Shooks Gap, and (106) shales of the
Rome formation, on the roadside at the eastern base of Shooks Gap; both in Bays Mountains, 10 miles (16.1 km.) south-
east of Knoxville [Keith, 1895, areal geology sheet], Knox County, Tennessee. :

(9a) Limestone on the south shore of the Holston River at Melinda Ferry, 5 miles (8 km.) southwest of Rogers-
ville [Keith, 1896a, areal geology sheet], Hawkins County, Tennessee.

(14a) Sandstone of the Rome formation along First Creek Gap, 4 miles (6.4 km.) north-northeast of Knoxville
[Keith, 1905, areal geology sheet], and (374) in the suburbs of and 4 and 11 miles (6.4 and 17.7 km.) north-northeast
of Knoxville; both in Knox County, Tennessee.

(188) Shale in the street northeast of Printuf House, Gadsden, Etowah County, and (145) shale in bluff on
Coosa River east of Turkeytown, 8 miles (12.8 km.) northeast of Gadsden, Etowah County; both in Alabama.

(362a) Sandy shale a short distance west of Cave Spring; (138a) shales in the Rome formation west of the ceme-
tery west of Rome; and (140c) shales at edge of hill on the road leading west of Cave Spring; all in Floyd County,
Georgia.

Specimens that are somewhat doubtfully referred to this species occur at the following
localities:
Middle Cambrian: (14t) Limestone lying on slope between the Cambrian quartzite and the massive blue lime-
stone 100 feet (30.5 m.) above, Mount Nebo Canyon, 3 miles (4.8 km.) southeast of Mona, Juab County, Utah.

(92x) Conasauga (“‘Coosa”’) shale, at Yanceys Bend, Coosa River; and (90) Conasauga (“Coosa”) shale on.
Edwards’s farm, near Craigs Mountain; both southeast of Center, Cherokee County, Alabama.

LINGULELLA? SIMPLEX (Barrande).

Plate XXXII, figures 4, 4a—b.

Lingula simpler BaRRANDE, 1879, Systéme silurien du centre de la Bohéme, vol. 5, pt. 1, Pl. CIV, figs. vr: 14. (Not
described, but figured as a new species. Figs. 1A, 4A, and 4B are reproduced in this monograph, Pl. XXXII,
figs. 4, 4a—b, respectively.)

This species, like Lingulella? insons (Barrande), is one of the forms that, with the present
evidence, is probably to be referred to Lingulella. All that is known to me of the species is shown
in the figures copied from Barrande.

FORMATION AND LOCALITY.—Lower Ordovician: (303a) Etage D3 at Trubin; and (303p) Etage d3 in the environ.
of Beraun; both [Barrande, 1879b, Pl. CIV] in Bohemia, Austria-Hungary.

LINGULELLA TARPA (Walcott).
\ “
? Plate XXIII, figures 2, 2a—c.

Obolus (Lingulella) tarpa Waucort, 1898, Proc. U. 8. Nat. Mus., vol. 21, pp. 417-418. (Described and discussed as

below as a new species.) 5

General form elongate ovate, with the ventral valve subacuminate, and the dorsal valve
ovate in outline. There is considerable range of variation in the outline of both valves, owing
in part, possibly, to distortion. The convexity of the two valves is fairly strong, as far as
can be determined from the somewhat compressed condition of the shells in the shale and
calcareous sandy shales. The largest ventral valve in the collection has a length of 14 mm.
The average length of the ventral valve is from 10 to 12 mm. One 11.5 mm. in length has a
width of 8 mm.

None of the specimens of the collection show the outer surface, and only traces of con-
centric and radiating lines have been observed on the inner surface. The shell appears to be
moderately thick, and formed of numerous lamelle that were oblique to the outer layer in the

OBOLIDA. 535

anterior portions of the shell, in this respect resembling the shell of Lingulella acutangula
(Roemer) (Pl. XVII, figs. 1m, 10). :

Casts of the interior of the ventral valve have a moderately long area divided midway by
the cast of a strong pedicle furrow and marked about midway between the pedicle furrow and
the lateral margin by a sharp flexure line; striz of growth cross the area parallel with its base
and arch over the cast of the pedicle furrow. The area of the dorsal valve is relatively short,
arching forward slightly at the median portion. The only interior markings observed are
seen in the casts of the ventral valve where the visceral area and a portion of the main vascular
sinuses are imperfectly preserved.

Observations.—The external form of this species strongly recalls that of Lingulella acutangula
(Roemer), but the material istooimperfect to identify it with the latter. It occurs at a consider-
ably lower geologic horizon, and what is preserved of the interior markings of the ventral valve
indicates a considerable difference in the position of the visceral area (Pl. XVII, fig. 1c, and
Pl. XXIII, fig. 2a).

FoRMATION AND LOCALITY.—Middle Cambrian: (11) Sandstones and shales of the Rome formation, about 1 mile
(1.6 km.) east of Post Oak Springs | Hayes, 1894, areal geology sheet], Roane County; and (11a) sandstone between First
and Armstrong creeks, in the southeast corner of the Maynardville quadrangle (U. S. Geol. Survey), Union County;
both in Tennessee.

LINGULELLA TEXANA Walcott.

Plate XLIX, figures 3, 3a.

Tnngulella texana Watcortt, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, p. 71, Pl. VIII, fig. 5. (Characterized as
below as a new species. Fig. 5 is copied in this monograph, Pl. XLIX, fig. 3.)

This is a small but distinctly marked species, represented by two dorsal valves occurring
in the Upper Cambrian limestones of central Texas. The dorsal valves are oval, and quite |
strongly convex. The shell appears to have been rather thick, and the outer surface is marked
by strong, radiating striz, a feature which is characteristic of the species. They are crossed
by fine, concentric striz and lines of growth. The position of the muscle scars and the size and
character of the area are shown by Plate XLIX, figure 3a.

FoRMATION AND LOCALITY.—Upper Cambrian: (369) Sandstones at the base of the Elvins formation, in the eastern
limits of the town of Flat River, St. Francois County, Missouri.
(69) Limestones near Honey Creek; and (70) limestone near Morgans Creek; both in Burnet County, Texas.

LINGULELLA TORRENTIS (Matthew).

Plate XX XV, figure 7.

Leptobolus torrentis MartuEw, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, pp. 74-75, Pl. VI,
fig. 1. (Described as belowas a new species. The specimen represented by fig. 1 is redrawn in this monograph,
Pl. XXEXY, fig. 7.)

Leptobolus atavus tritavus Matrunw, 1903, idem, p. 109, Pl. VI, figs. 5a-c. (Characterized as a new variety.)

The original description by Matthew follows:

Shell thin, surface shining. Form elongate oval.

Ventral valve obtusely pointed at the back, somewhat acutely rounded in front; elevated along the middle; some-
what flattened along the sides within the margin.

By decortication a low boss and a transverse furrow behind it are exposed on the mold, about three-quarters of the
length of the valve from the hinge; if this boss marks the front of the callus, the central muscles are unusually far
forward, more advanced even than in Z. atavus of the Etcheminian terrane. There are faint impressions of the lateral
septa on the sides of the valve.

The surface of the shell is covered with minute, low tubercles, cancellate in arrangement; through these can be
traced faint parallel lines, concentric to the umbo. Along the median third in places can be seen about six broad,
flat ridges, radiating from the direction of the umbo; these break the continuity of the concentric ridges.

Length, 3 mm.; width, 2 mm.; depth, 0.5 mm.

The ventral valve of ‘‘Leptobolus atavus tritavus”’ Matthew is similar in form to the type of
Lingulella torrentis. Compare figures 1 and 5a of Matthew [1903, Pl. VI]. The surface characters

536 CAMBRIAN BRACHIOPODA.

appear to be identical. The dorsal valve is elongate oval in outline, resembling the same valve
in Lingulella atava (Matthew).

ForMATION AND LOCALITY.—Middle Cambrian: (344f [ Matthew, 1903, p. 72]) Shales of the Coldbrook terrane of
Matthew, on Dugald Brook, Indian River; and (344e [Matthew, 1903, p. 78]) shales of Division Eld of Matthew’s [1903,
pp. 28 and 29] Etcheminian, on Boundary Brook, eastern side of the HEscasonie Indian Reservation; both in eastern
Cape Breton, Nova Scotia.

V LINGULELLA TRIPARILIS (Matthew).

Text figures 44a], page 537; Plate XLV, figures 2, 2a-f.

Obolus triparilis MartHEw, 1902, Trans. Roy. Soc. Canada, 2d ser., vol. 8, sec. 4, No. 3, p. 94, PI. I, figs. 2a-e. (Dis-
cussed as a new species. )

Obolus discus MarruEw, 1902, idem, p. 94, Pl. I, figs. 3a-d. (Mentioned as a new species.)

Lingulella longovalis MarrHEw, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, pp. 123-125, Pl. VI,
figs. 3a-f. (Described and discussed as a new species. Figs. 3b and 3d are represented in outline by text figs.
44h and 44h’, respectively, p. 537, of this monograph.)

Obolus (Hoobolus) triparilis MarrHew, 1903, idem, pp. 136-137, Pl. VIII, figs. 4a-c; Pl. IX, figs. la-b.
(Described and discussed as a new species. Pl. VIII, figs. 4a-c, is copied from Matthew, 1902b, Pl. I, figs.
2a-c; Pl. VIII, fig. 4a, and Pl. IX, fig. la, are represented in outline by figs. 44b and 44b’, respectively, p. 537,
of this monograph. ) :

Obolus (Hoobolus) discus MartHEw, 1903, idem, pp. 138-139, Pl. VIII, figs. 3a-d. (Described and discussed as a new
species. Figs. 3a-d are copied from Matthew, 1902b, Pl. I, figs. 3a-d; figs. 3aand 3c arerepresented in outline by
figs. 44a and 44a’, respectively, p. 537, of this monograph.)

This species is distinguished from Lingulella (Lingulepis) gregwa (Matthew) by its outline.
The range of variation in its form covers both the types of the species and the types of ‘“ Lin-
gulella longovalis’’ Matthew and ‘‘Obolus (Eoobolus) discus” Matthew. Matthew assigns specific
value to variations in length and breadth of the visceral areas of the valves. I do not find
that this holds good, as the shells from the same layer of rocks and not distinguishable by
other characters vary in the length of the visceral area of the dorsal valve from a point back
of the center to nearly the front of the valve. There is also considerable variation in the
ventral valve. On the same shell there is a variation of the surface characters from the
nearly plain, concentric striz to undulating striz, with minute points on the crest. This is
also true of the surface of Lingulella (Lingulepis) gregwa (Matthew).

The ‘‘central” scar in the dorsal valve, mentioned by Matthew [1903, p. 136] as charac-
terizing ‘‘Obolus (EHoobolus) triparilis,” is at the bifurcation of the median ridge, and appears
to be a slight depression just in advance of the bifurcation and not a true muscle scar. The
variation in outline of the valves is shown in figures 44a-l.

No specimens among the types sent by Matthew nor in our material show areas like those
represented by figures 44b’ and 44h’. The area is not preserved on the dorsal valves of L.
triparilis sent by Matthew, and the area of the dorsal valve of his ‘‘Z. longovalis” does not
extend so far down the lateral slopes of the shell as represented in the figure.

The variation in the length and strength of the visceral area in the two valves is also
outlined from specimens showing their position. Among the specimens from the same layer
of rock there is a transition in form from Lingulella triparilis to Lingulella (Lingulepis) longi-
nervis (Matthew) of a somewhat later stratigraphic horizon. This is illustrated im figures 44f—k.

The surface characters are of the same type in Lingulella (Lingulepis) gregwa “Glatthew),
L. (L.) longinervis (Matthew), and Lingulella triparilis.

““Obolus (Hoobolus) discus” Matthew appears to be based on imperfect specimens of the
short, broad form of L. triparilis. With the types of ‘‘O. (#.) discus,” L. trvparilis, and
‘*L. longovalis” before me, I am not able to discover differences of specific value between them.
All have the same surface characters, and the gradations in form unite them into one species.

ForMATION AND LOCALITY.—Middle Cambrian: (13t/ and 18t)¢ Sandstones at the base of Division E1b; (344g)
[Matthew, 1903, p. 77]) shales of Division Elc; (13t’’) sandstones of Divisions Ele and H1d; (344h [Matthew, 1903,

a13¢t is the type locality, though the specimens in the United States National Museum collections to which that number was assigned were
collected later than Matthew’s type specimens.

:
t

OBOLID&. 537

p. 79]) sandy layers in the shales of Division Ele; and (10p) sandstone just below the waterfall in Division E2b; all
in Matthew’s [1903, p. 21] Etcheminian, on Dugald Brook, Indian River Valley, eastern Cape Breton, Nova Scotia.

(307d [Matthew, 1903, p. 79]) Sandy limestone of Division E2a? of Matthew’s Etcheminian, on Young (McFees)
Point, George River, Cape Breton, Nova Scotia.

Figure 44.—Lingulella triparilis (Matthew); outlines illustrating variation in form of shells now referred to Lingulella triparilis. a, a’, Ventral
and dorsal valves of “‘ Obolws ( Hoobolus) discus” [Matthew, 1903, Pl. VIII, figs. 3a and 3c]. 6, b’, Ventral and dorsal valves of Lingulella
triparilis (Matthew, 1903, P1. VIII, fig. 4a,and Pl. IX, fig.1a]. c-g, c’-g’, Ventral and dorsal valves from Locality 18t’’, sandstones of Division
Ele of Matthew, Dugald Brook, illustrating the gradation in form between shells referred to Z. triparilis and “‘ ZL. longovalis.” h, h’, Ventral
and dorsal valves of ‘‘ LZ. longovalis” [Matthew, 1903, Pl. VII, figs. 3b and 3d]. iI, 7’-!’, More elongate ventral and dorsal valves from speci-
mens associated with those represented by c-g.

LINGULELLA TUMIDA Matthew.
Plate XXIV, figures 7, 7a-d.

Lingulella tumida Matruew, 1899, Bull. Nat. Hist. Soc. New Brunswick, vol. 4, pt. 3, No. 18, p. 200, Pl. I, figs. 2a-c.
(Described as a new species.)

Obolus (Lingulepis) gregwa Wautcorrt (in part) fot 0 (MatrHEw)], 1901, Proc. U.S. Nat. Mus., vol. 23, p. 692-694. (Mat-
thew’s Lingulella tumida is here referred to and described sri Lingulella (Giagoileais) gregwa.)

Lingulella tunada MartHew, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, p- 123, Pl. VI, figs.
6a-c. (Described and discussed. Figs. 6a-c are copied from Matthew, 1899b, PI. I, figs. 2a-c.)

This shell resembles Lingulella martinensis Matthew and some forms of Lingulella (Lin-
gulepis) exigua (Matthew) in outline of the valves. At first I thought it should be placed with
the latter species, which I had [1901, p. 692] by error identified with Lingulella (Lingulepis)

gregwa (Matthew). It is uniformly smaller than L. (L.) exigua, and differs in the more uniform
concentric lines and striz of growth.

538 CAMBRIAN BRACHIOPODA.

Matthew’s material is poor, but in the collections made by S. Ward Loper there is an
abundance of specimens showing some variations in form. The surface is marked by strong,
concentric lines of growth, with narrow bands of finer and somewhat minutely irregular striz.
Depressed, irregular, and bifurcating radiating lines show on very perfectly preserved shells.

FORMATION AND LOCALITY.—Middle Cambrian: (13i) Sandstones of the ‘“‘Johannian’’ Division of Matthew’s
section, on Gillis Brook, East Bay, east of Bras d’Or Lake; and (18r) sandstone at a little different horizon than that

of Locality 13i, on Gillis Brook, Kast Bay, east of Bras d’Or Lake; and (18n’)@ sandstones of Division E3e of Mat-
thew’s [1908, p. 21] Hicheminian, Dugald Brook, Indian River; all in eastern Cape Breton, Nova Scotia.

LINGULELLA UPIS (Walcott).

Plate XXXVI, figures 3, 3a.

Obolus (Lingulella) wpis Waxcort, 1905, Proc. U. 8. Nat. Mus., vol. 28, pp. 331-332. (Described and discussed as
below as a new species. )

This is a small, elongate shell of the group to which Lingulella ora (Walcott) belongs. It
differs from the latter in being more elongate and in its marked surface characters, and from
L. collicaa (Matthew), L. flumens (Matthew), L. cania (Walcott), and allied forms, in having
a thick, strong shell and highly characteristic exterior surface.

The shell is thick, the anterior portions being made up of numerous lamellz oblique to
the exterior surface, in this respect resembling some of the species of Obolus having thick
shells. The exterior surface is marked by concentric lines of growth, with very fine, some-
what irregular strize between them. ‘These show very distinctly in the anterior portion of
the shell. Further back they become very irregular, giving a crenulated appearance to the
striz and lines of growth, and the surface looks as though it was formed of thin, imbricating
scales or lamellee. ;

Observations—The surface of Lingulella upis suggests that of Obolus ( Westomia) euglyphus
(Walcott), but I have been unable to find traces of the transverse lines characteristic of Westonia.

FORMATION AND LOCALITY.—Upper Cambrian: (14g and 14i) 6 Upper part of the limestones exposed 1 mile (1.6 km.)

west of Cherokee, San Saba County; and (14b) limestone on Cold Oreek, at north end of gorge opposite the north end
of Sponge Mountain, 2 miles (3.2 km.) south of the San Saba County line, in Llano County; both in Texas.

LINGULELLA WANNIECKI Redlich.

Plate XX XIX, figures 1, la—n.

Lingulella wanniecki Repurcw, 1899, Mem. Geol. Survey India, Paleontologia Indica, new ser., vol. 1, No. 1, The
Cambrian Fauna of the Eastern Salt Range, p. 7, Pl. I, figs. 9a-d. (Described and discussed as a new species.)

Obolus (Lingulella) wanniecki (Redlich), Waxcorr, 1905, Proc. U. 8. Nat. Mus., vol. 28, p. 332. (Described and dis-
cussed as below.)

General form broadly ovate, with the ventral valve obtusely acuminate and the dorsal
valve rounded subtriangular; convexity moderate in the specimens embedded in argillaceous
shales. There is considerable range of variation in the outlme of the valves; this is shown
in Plate XX XIX, for the ventral valve by figures 1, la—f, and for the dorsal valve by figures
lg-m. All that is known to me of the interior markings of the ventral valve is shown by
figures 1d-f, and of the dorsal valve by figures 1I1-n. The surface of the shell is marked by
concentric lines of growth and very fine closely undulating raised strize that mosculate so as to
give the surface a granulated appearance. This type of surface occurs on Lingulella isse (Wal-
cott) and ZL. wpis (Walcott). The anterior layers of the shell are marked by radiating and
concentric striz, and the interior of the shell has scattered puncte in addition to the radiating
and concentric striz. The shell is relatively thick and formed of several layers or lamelle
in addition to the very thin outer ornamented layer.

The visceral area of the ventral valve is short, and the main vascular sinuses are about
halfway between the center of the shell and the lateral margins. In the dorsal valve the

@13n’ is the type locality, but the specimens in the United States National Museum to which that number is assigned were collected later
than the type specimens.
b 14i is the type locality.

OBOLID. 539

visceral area is well developed beyond the center of the shell, and the vascular sinuses are
farther out proportionately than in the dorsal valve. The central and anterior lateral muscle
scars are placed on an elevated central ridge, on each side of a sharp median septum.

Observations.—This very pretty little shell occurs in great numbers in the dark argilla-
ceous shales with Redlichia noetlingi (Redlich). Redlich [1899, p. 7] states that it is the only
species of the genus in the collection sent to him. In the collections made by Fritz Noetling
I find associated with Redlichia noetlingi, Lingulella wanniecki, L. fuchsi Redlich, Acrothele
(Redlichella) granulata (Linnarsson); also specimens of a species of undescribed Hyolithes.

Among the American species of Lingulella, L. wanniecki may be compared in form with
L. desiderata (Walcott) and L. oweni (Walcott). Its surface is much like that of L. upis
(Walcott) and Z. ora (Walcott). It is distinct from all described species when its form and sur-
face are taken into consideration, as there is no species with its subtriangular form that has
its granulated surface.

The formations containing this fauna are referred to the Middle Cambrian, as there is no
evidence that the Cambrian fauna of India above the upper “‘Annelid sandstone,’’ as described
by Noetling and Redlich, is older.

FORMATION AND LOCALITY.—Middle Cambrian: (15r) @ Dark argillaceous shales at Khussak, Salt Range, India.

LINGULELLA WELLERI (Walcott).
i
Plate XX XVIII, figures 4, 4a—b.

Obolus (Lingulella) welleri Waucorr, 1902, Proc. U. S. Nat. Mus., vol. 25, p. 608. (Described and discussed essen-
tially as below as a new species.)

General form elongate ovate, with the ventral valve subacuminate and the dorsal valve
subelliptical. Owing to the more or less crushed condition of all the specimens the exact
convexity of the entire valve is unknown. Surface of the shell marked by numerous elevated
concentric lines of growth and very fine slightly irregular interstitial concentric striz.

When the outer edge is exfoliated the inner layers show fine radiating strie and con-
centric lines of growth. Nothing is known of the interior surface of the shell. The shell
appears to have been relatively thin and formed of several layers or lamellee.

A ventral valve 14 mm. in leneth has a width of 9 mm. and a dorsal valve 10 mm. in
length has a width of 7.5mm. In both valves the width is slightly increased by the flattening
of the shell.

Observations—This species occurs in association with Obolus (Westonia) stoneanus (Whit-
field) in an arenaceous, magnesian limestone. It differs from described species of Lingulella
in the elliptical form of its dorsal valve and the strongly filose concentric striz of the outer surface.

The dorsal valve has the outline of that of Obolus (Westonia) stoneanus but the ventral
valve is more acuminate and the characteristic Westonia surface of the latter is absent. Some
specimens of 0. (W.) stoneanus have the transverse imbricating lines only on the posterior
half of the valve, in which case the anterior half is much like that of Lingulella welleri.

The specific name is given in honor of Prof. Stuart Weller, who discovered the locality.

FORMATION AND LOcALIry.—Upper Cambrian: (11c) Hardyston quartzite [Weller, 1900, pp. 10 and 12], O’Donnell
and MeManniman’s quarry, Newton, Sussex County, New Jersey.

LINGULELLA WINONA (Hall).
Plate XVIII, figures 3, 3a-b.

Lingula winona Hau, 1863, Sixteenth Rept. New York State Cab. Nat. Hist., p. 126, Pl. VI, fig. 9. (Described as
a new species; see p. 540 for copy.)
Lingula winona Hat, 1867, Trans. Albany Inst., vol. 5, p. 102, Pl. I, fig. 9. (Copied from preceding reference. )

a Specimens from the type locality were given to the United States National Museum and this number was assigned to them.

540 CAMBRIAN BRACHIOPODA.

Lingula winona Hall, SARpESoN, 1896, Bull. Minnesota Acad. Nat: Sci., vol. 4, No. 1, pt. 1, p. 96. (Characterizes
specimens from new locality.)

Lingulella winona (Hall), Scaucunwr, 1897, Bull. U. S. Geol. Survey No. 87, p. 208. (Merely changes generic refer-
ence. )

The original description by Hall follows:

Shell small, subquadrilateral, the front nearly straight; sides nearly straight and parallel; apex obtuse, the
cardinal margins sloping at an angle of 80 degrees. Surface marked by fine concentric striz.

A cast of part of a ventral valve from Osceola, Wisconsin, that appears to belong to
this species, shows the visceral area and the main vascular sinuses (Pl. XVIIL, fig. 3). This
shell ig more convex and has a more rounded outline than the type shell, but I think that this
is owing to the fact that the type shells are pressed flat in the sandy shales and to a degree
distorted. Flattened shells at Osceola are much more quadrate in outline.

The species has been found at a number of localities, but very little more can be added to
the original description. The shell, although very small, is built up of two or more layers that
are lamellose toward the front of the shell. The outlines of the two valves when compressed
are shown by Plate XVIII, figures 3a and 3b.

The nearest form to Lingulella winona is L. mosia (Hall) of the Upper Cambrian. It
differs in the uniformly smaller size and its regular subquadrate outline.

The specific name is derived from Winona, Minnesota.

FORMATION AND LOCALITY.—Upper Cambrian: (78 and 78c) ‘‘St. Croix sandstone,” quarry near St. Croix River in

suburbs of Osceola, Polk County; (85x) upper beds of the “‘St. Croix sandstone” near Mazomanie, Dane County; »

(10v) shaly beds in the “St. Croix sandstone,” at Fox Glen, 8 miles (12.8 km.) east of Baraboo, Baraboo quadrangle
(U. S. Geol. Survey), Sauk County; (79) ‘‘St. Croix sandstone” in bluff near Hudson, St. Croix County; and (85s)
“St. Croix sandstone” at Prairie du Sac, Sauk County; all in Wisconsin- 2
(113) ‘‘St. Croix sandstone” at La Grange Mountain (or Barn Bluff), near Red Wing, Goodhue County, Minnesota.
(841) Near Lansing, Allamakee County, Iowa. io
t
LINGULELLA WINONA CONVEXA (Walcott).

Plate XVIII, figures 4, 4a-d.

Obolus (Lingulella) winona converus Watcorr, 1901, Proc. U. S. Nat. Mus., vol. 23, p. 691. (Discussed as below asa
new variety.)

A small relatively convex shell occurs abundantly in the brown sandstones at Osceola
that appears to be an intermediate form between Lingulella winona (Hall) and L. mosia (Hall).
It differs from L. mosia in being a shorter shell, and from L. winona in the more regularly ovate
to semicircular dorsal valve and more acuminate ventral valve.

Observations—The group of shells represented by L. winona, L. mosia, and their varieties
appears to range from the Middle Cambrian beds of Hudson, Wisconsin, up and into the Upper
Cambrian beds of Osceola, Wisconsin. There is so much variety of form owing to the condi-
tions of preservation that it is very difficult to be always sure of the correctness of the specific
reference. The variety convexa may be only the uncompressed form of L. winona, which is
usually flattened in the shaly sandstones, or it may be a distinet species. From the material
available for comparison this can not be clearly determined.

FORMATION AND LOCALITY.—Upper Cambrian: (78, 78s, and 78c)% ‘St. Croix sandstone” in quarry near St. Croix
River in suburbs of Osceola, Polk County; (79) “St. Croix sandstone” in bluff near Hudson, St. Croix County;
(85x and $85x) upper beds of the ‘St. Croix sandstone,” near Mazomanie, Dane County; (100) “St. Croix sandstone ”
near Menomonie, Dunn County; (79a) “‘St. Croix sandstone” in quarry and ledge, 0.5 mile (0.8 km.) southeast of
the county courthouse, Menomonie, Dunn County; (80) “St. Croix sandstone” 0.66 mile (1.1 km.) southwest of
the railway depot, Menomonie, Dunn County; (85s) ‘‘St. Croix sandstone” at Prairie du Sac, Sauk County; and
(185) “‘St. Croix sandstone” near Trempealeau, Trempealeau County; all in Wisconsin.

(75) ‘““Tonto” sandstone, near the water’s edge at the mouth of Kanab Canyon, where it enters the Grand Canyon
of the Colorado, Arizona.

a 78 is the type locality.

e
5
i
|
:

OBOLIDA. 541

L LINGULELLA wirtTut (Barrande).
Plate XXX, figure 7.

Lingula wirtht BARRANDE, 1868, Faune silurienne des environs de Hof, en Bavieére, p. 101, fig. 63. (Described and
discussed in French asa new species. Fig. 63 is reproduced in this monograph, Pl. XXX, fig. 7.)

Lingula wirthi BARRANDE, 1868, Neues Jahrb. fiir Mineralogie for 1868, p. 691, unnumbered plate, fig. 63. (Copy of
preceding reference.)

This is a more elongate shell than Obolus? bavaricus (Barrande), and is known only by
several casts. It has a length of 15 mm.; greatest width,9 mm. In many respects it resembles
LTingulella davisi (McCoy) of the Lingula flags of Wales.- The outer surface is marked by con-
centric lines and striz, as far as can be determined from the casts.
FoRMATION AND LOCALITY.—Passage beds between the Upper Cambrian and the Ordovician: (308¢e [Barrande,

1868a, p. 101) Suburbs of Hof; and (303f[Pompeckj, 1896a, pp. 7 and 8]) railway cut near Schellenberg, a little distance
back of the railway station at Neuhof, near Hof; both in Bavaria, Germany.

LINGULELLA ZEUS Nn. sp.
of Text figure 45.

This species is represented by one very minute specimen, a poorly preserved interior of a
suborbicular ventral valve, showing a fairly well defined area. The exterior surface was covered
with strong concentric striz.

Observations—This specimen is of particular interest as the only representative of the
genus Lingulella from Scotland, where it occurs associated with
Olenelloides armatus. The species is too poorly preserved for further
description or comparison.
~ PorMaTION AND LocaLiry.—Lower Cambrian: (316c) Shales from Locality M4197d
of the Geological Survey of Scotland, a band probably equivalent to either 6 or 7 of
the section on the north slope of Meall 4 Ghiubhais [Peach and Horne, 1907, p. 414] on

the Bruachaig River, 2 miles (3.2 km.) east-northeast of the Kinlochewe Hotel, Loch
Maree, Ross-shire, Scotland.

Ficure 45.—Lingulella zeus n. sp.
Interior of a ventral valve, the
type and only specimen, x 12,

LINGULELLA sp. undt. a. from Locality $16c, Lower Cam-
iA brian shales near Loch Maree,
/
sf Plate XXX, figure 13. Ross-shire, Scotland. The speci-

men is numbered M4197d in
the collections of the Geological

There are two specimens of the dorsal valve in the collection from Seecnenritar nae

the Olenus truncatus zone. The outer surface is marked by fine radi-
ating and concentric striz, and the inner surface by large puncte, scattered, as far as known,
in the anterior half of the valve.

FORMATION AND LOCALITY.—Upper Cambrian: (310k) Oeland Island, Sweden.

LINGULELLA sp. undt. b.

Imperfect specimens of a small, rather broad form of Lingulella occur in Middle Cambrian
shales at York, Pennsylvania. The outline of the shells is somewhat like that of Obolus willisi
(Walcott), but the material is too poor for specific determination.

FPoRMATION AND LOCALITY.—Middle Cambrian: (48d) Argillaceous shales in the railroad cut beside the gas house,
York, York County, Pennsylvania.
LEPTEMBOLON Mickwitz, subgenus of LINGULELLA. .
[Aextéc, small; and 2fojov, a wedge.]

Obolus (Leptembolon) Micxwirz, 1896, Mém. Acad. imp. sci. St.-Pétersbourg, 8th ser., vol. 4, No. 2, p. 199. (Char-
acterized and discussed as a new subgenus; see below for translation.)

Obolus (Leptembolon) Mickwitz, Waucorr, 1908, Smithsonian Misc. Coll., vol, 53, no. 4, Pl. XI, and pp. 142 and 144.
(Classification of subgenus. )

The original description by Mickwitz follows:

The subgenus Leptembolon is based on a species of Obolus, which externally resembles Lingula very closely,
and in fact was by earlier authors regarded as such. The specimens of the internal surfaces of the valves, however,

542 CAMBRIAN BRACHIOPODA.

showed, together with some suggestions of the last-mentioned genus [Lingula], unmistakable marks of the*genus Obolus,
so that the species, which would not be assigned to any of the other groups, had to be ranked in a special subgenus of
Hichwald’s genus.

The internal characteristics of the Cambrian and Silurian Lingule have not hitherto been established so com-
pletely as to render it possible to compare the organization of this extinct group in detail with the recent Lingula.
It is probable that more accurate knowledge of these oldest Lingulze will lead to a change in the generic designation.
A similar uncertainty of course exists also in regard to the relations of the genus Obolus to the above-mentioned Lin-
gulze, and if it be possible to ascertain the internal features of the latter to the same extent as in the genus Obolus,
O. lingulxformis will probably become the connecting link between these old extinct genera.

ty LINGULELLA (LEPTEMBOLON) LINGUL#FORMIS (Mickwitz).
Plate XIV, figures 5, 5a—b.

Obolus (Leptembolon) lingulxformis Mickwitz, 1896, Mém. Acad. imp. sci. St.-Pétersbourg, 8th ser., vol. 4, No. 2,
pp. 200-204, Pl. III, figs. 10-17. (Described and discussed in German as a new species; see below for trans-
lation. Figs. 17a-b are copied in this monograph, Pl. XIV, fig. 5.)

Obolus (Leptembolon) lingulexformis solidus Mickwrrz, 1896, idem, pp. 204-205, Pl. III, figs. 18 and 19. (Described
and discussed in German as a new variety.)

The original description by Mickwitz follows:

Shells moderately large, quite flatly arched. Outline pointedly oval to subtriangular. Beak and posterior

part of shell laterally somewhat flattened, forming two slightly pronounced roundish edges, which converge to the
tip of the beak. Anterior part of shell similarly flattened toward the anterior border.

Surface of shell very smooth, very lustrous, like varnish. Concentric striz very fine and regular, especially
sharp cut at the posterior borders. Growth lamellz indistinctly bordered. In age, clearly distinguishable by the
somewhat projecting borders of the lamellze. Anterior and lateral borders very thin, sharp-edged, brittle, lying
in the plane with the uncovered umbonal borders. Posterior part of the shell scarcely thickened, area more in shape

of covering of the hollow tip of the beak. Pleuroccelic part of the area somewhat prolonged into the lateral borders.”

Peduncular groove very broad, somewhat diminished toward the tip of the beak, lying deep but only flatly arched
on account of the deficient thickening of the beak. ‘Traces of the pseudo-area rectilinear, converging to the tip of
the beak.

Splanchnoccele of the large shell (ventral valve) drawn forth, anterior point of the same bordered in the shape
of a bow, and somewhat projecting. Terrace of the thickening of the posterior part of the shell diverging into the
brachioccele, longitudinally palmately striate. Central groove of large shell very flat, posterior part indefinitely bor-
dered, tip drawn out, parallel bordered and anteriorly semicircularly rounded. Corneous processes of the small shell
(dorsal valve) strongly receding, sinus indefinitely flattened. Median swelling of small shell strongly developed,
beginning in the sinus as a thin, roundish ridge, gradually swelling, reclining beyond the places of attachment of the
anterior lateral muscles, and ending shortly before the anterior border in the shape of a pestle. Principal vessels
distinguishable in their beginnings, not traced in the brachioccele. Peripheral canals and accessory vascular furrows.
in both shells only distinguishable in indistinct traces. Places of attachment of the umbonal muscles large, longi-
tudinally striate, not to be separated from the place of attachment of the peduncular muscle in the large shell. Places.
of attachment of the central and outside lateral muscles to both sides of the central groove of the large shell, separated
from each other and from those of the middle lateral muscles. The latter lie before the semicircularly bordered apex
of the central groove. Central muscles (with their advance corresponding to the growth of the animal) leaving behind,
in the small shell, a row of traces, which converge into the sinus. Places of attachment of the combined outside and
middle lateral muscles, as also those of the transmedian muscles of the small shell, very near the border of the shell.

Observations: The shells of O. lingulxformis show a different form of outline in their youth than in their age.
For the species of the subgenus Huobolus, we have demonstrated a proportional growth, and the same aiso takes place
in the species of the other subgenera, as the consideration of the concentric strie teaches, which marks the stages of
age. The form of outline remains the same, except in the very first stages of youth. In O. lingulxformis the outline
of the shell is elliptic until in old age, and then first begins to become subtriangular through the growth lamellz pro-
jecting mostly at the anterior border and anterior lateral borders. Self-evidently, the separation of the substance
of the shell takes place also in this stage along the entire border of the shell (including the area), but the lamelle run,
so far as their external part (which forms the surface of the shell) comes into consideration, so sharply into the lateral
borders that they do not help to broaden the posterior borders of the shells, but only to thicken them vertically. The
outline of the posterior part of the shell, therefore, remains the same, while the anterior part steadily gains in breadth.

In connection with this manner of formation stand the extraordinarily sharply sculptured concentric striz at.
the lateral borders of the shell, which are closely crowded against each other.

This characteristically subtriangular outline, which, in connection with the flat arching of the shell, marks the
typical form of O. linguleformis, is, however, in some specimens given to essential deviations. The beak becomes

ee, fee ee en

OBOLIDA. 543

broader, and the form of the outline approaches more to the elliptic. At the same time the shell is much more strongly
arched. A small shell whose outline deviates only slightly from the typical form is arched much more than the nor-
mal specimens. These transition forms point, as we see, toward the variety solidus.

The typical form shows two slightly pronounced roundish edges which converge into the tip of the beak and
are caused by a lateral flattening of the posterior part of the shell. In like manner the anterior part of the shell is
somewhat flattened toward the anterior border. These characters are first plainly perceptible by reflected light,
and are much less developed in the described roundish forms. A peculiar correlation also seems to exist between
the form of the shell and the strength of the shell. The latter is the slightest in the typical form, increases in the
roundish form, and acquires the maximum in O. lingulxformis solidus.

The thinness of the shell of the species in question is pronounced, especially in the deficient thickening of the
tip of the beak, which in this regard reminds one of the recent lingulas. Here, as well as there, the broad posteriorly
diminished peduncular groove is shallow and only indefinitely bordered, and sunk in the area of the large shell. 0. lin-
gulxformis reminds one, more than all other species of Hichwald’s genus, in the formation of the area of the small
shell, of the recent Lingula with which this part is, to be sure, in a still more pronounced manner, a mere covering
of the thin-walled tip of the beak with the corneous area lamelle. ‘

The configuration of the inner surface of the shell is, in relation to the deficient thickening, quite distinctly devel-
oped. In its projecting tip the splanchnoccele of the large shell in some measure resembles the corresponding formation
of Lingula anatina. On the other hand, the small shell shows the three-lobed form, which is peculiar to the genus
Obolus and is continued by the aberrant position of the places of attachment of the muscles.

The thickening of the posterior part of the large shell is reduced to a wall-like rim whose pointed upper edge
incloses the parietal band. The declivity of this rim into the brachioccele is quite steep and marked at its middle,
circular-formed, projecting part by semewhat diverging longitudinal swellings palmately arranged; the slope into the
splanchnoccele is flatter and is lost in the indefinitely bordered central groove, from which only the strongly drawn
forth, parallel-bordered, somewhat anteriorly broadened, and rounded-off tip is clearly distinguishable by a slight
but sharply bordered depression.

As often mentioned, the places of attachment of the middle lateral muscles, which are removed from the places
of attachment of the central muscles, and united to one surface, lie before the tip of the central groove. The places
of attachment of the central muscles are oval and lie on both sides of the drawn-out apex of the central groove. They
show a coarse transverse striation, which is posteriorly continued farther than the places of attachment, and owes its
origin to the gradual advance of the central muscles, whose traces were only partly covered by a slight secretion of
lime, A similar condition takes place with the places of attachment of the outside lateral muscles of the large shell,
which lie, as with Schmidtia, close to the inner sides of the principal vascular canal, far removed from those of the cen-
tral muscles, and somewhat pushed back. Yet more striking is this succession of exposed traces with the places of
attachment of the central muscles of the small shell, in which it may be followed from the inner sides of the corneous
processes to the extreme tip of the sinus.

The last-mentioned small shell of the variety solidus shows very distinctly—namely, at the right side—the places
of attachment of the combined middle and outside lateral muscles as well as those of the transmedian muscles, while
the umbonal muscle has left less distinct traces. The first-mentioned places of attachment lie so close to the border
of the sheli that the pleurocceles are reduced to small, ribbon-shaped striz. This form of the pleuroccele stands
in connection with the previously mentioned law of growth of the shells.

In the large shell the places of attachment of the combined anterior lateral and transmedian muscles, likewise
on the right side, are quite distinctly pronounced, while the places of attachment of the divided umbonal muscles
and peduncular muscle form a somewhat indefinitely bordered, coherent surface, which is longitudinally striate in
the middle.

Very striking to the eye is the strongly developed median swelling of the small shell, which separates the dis-
tinctly depressed oval places of attachment of the anterior lateral muscles, and reaches, with its pestle-shaped swelled
ends, nearly to the anterior border of the shell; of the circulatory system only the posterior parts of the principal
vessels (with the exit out of the splanchnoccele) are unfailingly distinguishable. The concentric striz of the small
shell are insufficiently covered furrows of separation of the growth lamelle.

FoRMATION AND LOCALITY.t—Passage beds betweer the Upper Cambrian and the Ordovician: ‘“‘Glauconite sand-
stone” at the following localities: (396) at Baltischport, 30 miles (48 km.) west of Reval; (396a) at Leppiko near Leetz,
on the eastern side of the Baltischport peninsula, about 25 miles (40.3 km.) west of Reval; (896b) at Fall, 15 miles (24 km.)
west of Reval; (396c) at the mouth of Fahna Brook, east of Fall, about 15 miles (24 km.) west of Reval; (396d) at
Domglint in Reval; and (396f) in the western part of the east Baltic region; all [Mickwitz, 1896, p. 203] in the Gov-
ernment of Esthonia, Russia.

Upper Cambrian: (395) Obolus sandstone at Joa, near Jegelecht, 12 miles (19.3 km.) east of Reval, Government
of Esthonia, Russia.

a Localities 395 and 396a are represented in the United States National Museum collections.

544 CAMBRIAN BRACHIOPODA.

LINGULEPIS Hall,¢ subgenus of LINGULELLA.
[Lingula, a tongue; and exc, a scale.)

Lingulepis Hau, 1863, Sixteenth Ann. Rept. New York State Cab. Nat. Hist., p. 129. (Described as a new genus.)

Lingulepis Hall, Merk and Hayprn, 1865, Smithsonian Contrib. Knowl., No. 172, Paleontology Upper Missouri,
pt. 1, pp. land 2. (Described and discussed.)

Lingulepis Hawi, 1867, Trans. Albany Inst., vol. 5, p. 106. (Copied from Hall, 1863, p. 129.)

Lingulepis Hall, Datu, 1870, Am. Jour. Conchology, 2d ser., vol. 6, pt. 2, pp. 154 and 161. (Described.)

Lingulepis Hall, Mrnx, 1871, Proc. Acad. Nat. Sci. Philadelphia for 1871, vol. 23, pp. 186-187. (Notes on genus in
discussion of “ Lingulella ? lamborni.”’)

Lingulepis Hall, Zrrrpx, 1880, Handbuch der Palzontologie, Bd. 1, Abth. 1, p. 664. (Described in German.)

Lingula (Lingulepis) (Hall), OzHiERT, 1887, Manuel de conchyliologie, by Fischer, p. 1261. (Described in French.)

Lingulepis Hall, Hatt and CLrarKs, 1892, Eleventh Ann. Rept. State Geologist New York for 1891, pp. 231-232.
(Described.) :

Lingulepis Hall, Hatt and CrarKe, 1892, Forty-fiftth Ann. Rept. New York State Museum for 1891, pp. 547-548.
(Copy of preceding reference. )

Lingulepis Hall, Hart and Cuarxe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, pp. 59-62, and 164. (Origi-
nal description copied, p.59; genus described and discussed, pp. 59-62; and derivation of genus shown graphi-
cally, p. 164.) :

Lingulepis Hall, Scxucuert, 1897, Bull. U. 8. Geol. Survey No. 87, p. 258. (Lingulella and Lingulepis compared.)

Lingulepis Hall, Watcorr, 1897, Am. Jour. Sci., 4th ser., vol. 3, p. 404. (Re-refers all the species that have been
placed under Lingulepis.)

Obolus (Lingulepis) (Hall), Watcorr, 1899, Mon. U.S. Geol. Survey, vol. 32, pt. 2, pp. 443-444" (Copy of preceding
reference, except that Lingulepis and Lingulella are made subgenera of Obolus.)

Obolus (Lingulepis) (Hall), Waxcorr, 1901, Proc. U. S. Nat. Mus., vol. 23, p. 683. (Characterized.)

Lingulepis Hall, MatrHew, 1902, Trans. Roy. Soc. Canada for 1902, 2d ser., vol. 8, sec. 4, No. 3, p. 102. (Discussed.)

Lingulepis Hall, Martarew, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, p. 126. (Described
and discussed. Hall’s original description.copied also.)

Lingulepis Hall, Grapav and Samer, 1907, North American Index Fossils, vol. 1, p. 193. (Characterized.)

Lingulella (Lingulepis) (Hall), Watcorr, 1908, Smithsonian Misc. Coll., vol. 53, No. 4, Pl. XI, and pp. 142 and 144.
(Classification of subgenus.)

Genotype.—Lingula acumunata Conrad.

Schuchert states in his bibliography [1897, p. 258] that the only essential difference between
Lingulepis and Lingulella is that the ventral beak of the former is often much attenuated.
He does not refer to the interior markings of the valves, which have been illustrated as of
a peculiar character by Hall [1892c, p. 60]. I quite agree with Schuchert, and I find that,
with a fairly good series showing the interiors of both valves, all the essential markings of the
vascular system and muscle sears are the same as in Lingulella, except as the form of the ven-
tral valve changes the outline of the visceral area. When a shell of Lingulella (Linguleps)
acuminata (Conrad) (Pl. XLII, figs. 1g, 1h) is less attenuate than usual it is almost a good
Lingulella, both as regards external form and interior markings. It is a fact, however, that
many hundreds of specimens with a wide geographic distribution show a persistent form that
is readily recognized, and for this reason, and also for convenience of classification, I give Lin-
gulepis a subgeneric value.

a The synonymy for this subgenus does not give a complete record of the various genera under which the species now included in Lingulepis
were formerly placed; it gives only those references in-which the genus is discussed or described. To complete the record the following mere
generic references are listed:

Lingula Conrad [1839, p. 64]. Lingulepis Whitfield [1880, pp. 335 and 337; 1882, ~
Lingula Emmons [1842, p. 268]. p. 169; 1884, p. 141].

Lingula Hall [1847, pp. 3 and 9; 1851, p. 204). Lingulepis Dwight [1886, p. 208].

Lingula Owen [1851, p. 170; 1852, p. 583]. Lingulella Matthew [1891, p. 146).

Orbicula Owen [1852, p. 583]. Glossina Wall and Clarke [1892a, P1. I, figs. 10 and 11].
Lingula Emmons [1855, pp. 202 and 203]. Lingula (Glossina) Hall and Clarke [1892c, Pl. I
Lingula Billings [1856, p. 34). figs. 1 and 2].

Lingula Wall [1862, pp. 21 and 435). Lingula James [1895, p. 884].

Lingula Hayden [1862, p. 73]. Lingulepis Matthew [1895b, pp. 256 and 257].
Lingula Billings [1863, p. 102). Lingulepis Walcott [1897a, p. 404].

Lingula Chapman [1863, p. 187]. Lingulella Matthew [1899, p. 199].

Lingula Emmons [1863, p. 92]. Obolus (Lingulepis) Walcott [1901, p. 692].

Lingula Chapman [1864, p. 159]. Lingula Matley [1902, p. 141].

Lingula Holl [1865, p. 102]. Obolus (Lingulelia) Walcott [1902, p. 607].

Lingula Salter [1865, p. 102]. Obolus (Lingulepis) Walcott [1905a, p. 333; 1906,
Tingula Davidson [1866, pp. 41 and 53). p. 567].

Lingula Phillips [1871, p. 68]. Lingulella (Lingulepis) Walcott [1908d, p. 721.

OBOLIDA. 545

The visceral area of Obolus sinoe (Pl. X XVI, fig. 2e) is somewhat like that of Lingulella
(Lingulepis) acuminata (Pl. XLII, fig. 1g), and also resembles the visceral area of the ventral
valve illustrated by Hall [1863, Pl. VI, fig. 15]. The condition of preservation and the original
impress made by the different parts of the animal on the shell varies so much in shells of the
same species that it is difficult, without a large series of specimens, to decide definitely upon
generic or specific characters in the Obolidz. This is particularly true of Obolus, Lingulella,
and Lingulepis. ©

Of the 14 species and 2 varieties referred to Lingulepis from the Cambrian, 1 species
occurs in the Lower Cambrian, 9 species and 2 varieties in the Middle Cambrian, and 5 in
the Upper Cambrian. One species, L. (L.) acuminata (Conrad), is common to the Middle and
Upper Cambrian and Ordovician.

For the species that have been referred to Lingulepis and which are now referred to other
genera, see pages 62-63.

4 LxNGULELLA (LINGULEPIS) AcuMINATA (Conrad).4

Plate XXXIV, figures 3, 3a-e; Plate XL, figures 1, la-s; Plate XI, figures 1, lan; Plate XLII, figures 1, la-o.

Lingula acuminata Conran, 1839, Third Ann. Rept. New York State Survey, p. 64. (Described as a new species.)

Lingula antiqua Emmons, 1842, Nat. Hist. New York, Geology, pt. 2, p. 268, fig. 68. (Occurrence discussed. Fig. 68
is copied in this monograph, Pl. XL, fig. la.)

Lingula antiqua Emmons, Hat, 1847, Nat. Hist. New York, Paleontology, vol. 1, pp. 3-4, Pl. I, figs. 3a-e. (Described
and discussed as a new species, but uses Emmons’s name.) ;

Lingula acuminata Conrad, Haut, 1847, idem, p. 9, figure with footnote. (Copies the original description of Conrad,
1839, p. 64. The figure is copied in this monograph, Pl. XL, fig. 1.)

Tingula prima Owen, 1851, Proc. Am. Assoc. Adv. Sci. for 1851, p. 170. (Mentioned.)

Lingula antigua Emmons, OWEN, 1851, idem, p. 170. (Mentioned.)

Lingula antiquata Emmons, 1855, American Geology, vol. 1, pt. 2, pp. 202-203, Pl. IV, fig. 7. (Described and dis-
cussed. Fig. 7 is copied from Emmons, 1842, fig. 68, p. 268.)

Eingula acuminata Conrad, Emmons, 1855, idem, p. 203, Pl. IV, fig. 9. (Described. Fig. 9 is copied from Hall, 1847,
p. 9, footnote.) ;

Lingula prima Owen, Bintines, 1856, Canadian Naturalist, Ist ser., vol. 1, p. 34, fig. 1. (Described.)

Lingula antiqua Emmons, Bintines, 1856, idem, p. 34, fig. 2. (Characterized)

Lingula acuminata Conrad, Brutines, 1863, Fifteenth Rept. Geol. Survey Canada, p. 102, figs. 8a-g. (Mentioned.)

Lingula acuminata Conrad, CuarmMan, 1863, Canadian Jour. Ind., Sci. and Art, new ser., vol. 8, p. 187, fig. 155. (Men-
tioned.)

Lingula antigua Emmons, 1863, Manual of Geology, 2d ed., p. 92, fig. 77. (Mentioned. Fig. 77 is copied from Emmons,
1842, fig. 68, p. 268.)

Lingula acuminata Conrad, CHarman, 1864, Minerals and Geology of Canada, p. 159, fig. 155. (Text and figure copied
from Chapman, 1863, p. 187, fig. 155.)

Lingulepis minima WaitrreLp, 1884, Bull. Am. Mus. Nat. Hist., vol. 1, No.5, p. 141, Pl. XIV, figs.1 and 2. (Described
and discussed as a new species.)

Lingulepis minima Whitfield, Dwieut, 1886, Proc. Am. Assoc. Ady. Sci. for 1885, p. 208. (Mentioned.)

Lingulepis acuminata Conrad, Dwieur, 1886, idem, p. 208. (Mentioned.)

Tingula antiqua Emmons, James, 1895, Am. Naturalist, vol. 29, p. 884, fig. 1. (Mentioned. Fig. 1 is copied from
Emmons, 1842, fig. 68, p. 268.)

Lingulepis acuminata (Conrad), Marraew, 1895, Trans. Roy. Soc. Canada for 1894, 2d ser., vol. 1, sec. 4, No, 13,
pp. 257-258, Pl. Il, figs. 5a-b. (Described and discussed.)

Lingulepis acuminata (Conrad), ScHucHERT, 1897, Bull. U. 8. Geol. Survey No. 87, p. 259. (Discussed.)

Lingulepis acuminata (Conrad), Waucorr, 1897, Am. Jour. Sci., 4th ser., vol. 3, p. 404. (Merely changes generic
and specific references.)

Obolus (Lingulepis) acuminatus (Conrad), Watcorr, 1899, Mon. U.S. Geol. Survey, vol. 32, pt. 2, p. 443. (Merely
changes generic and specific references. )

Synonymy of the forms that have been referred to Lingulepis pinnaformis (Owen) from
the Mississippi Valley, and which are now referred to Lingulella (Lingulepis) acuminata (Conrad):

Lingula prima Owen, Hatt, 1851, Rept. Geology Lake Superior Land District, by Foster and Whitney, pt. 2, p.
204, Pl. XXIII, figs. la-e. (Described and discussed; dorsal valves.)

a The synonymy for this species is given in two parts; first, the synonymy of the forms that have been referred to the species acwminata;
second, the synonymy of the forms that have been referred to the species pinnaformis. The latter species is now considered to be a synonym of
the former.

62667°—vot 51, pr 1—12——35

D46 CAMBRIAN BRACHIOPODA.

Lingula antiqua Emmons, Hatt, 1851, Rept. Geology Lake Superior Land District, by Foster and Whitney, pt. 2,
pp. 204-205, Pl. XXIII, figs. 2a-c. (Discussed; ventral valves.)

Lingula pinnaformis OWEN, 1852, Rept. Geol. Survey Wisconsin, Iowa, and Minnesota, p. 583, Pl. 1s, figs. 4, 6, and 8.
(Described.)

Lingula antiqua Emmons, Hatt, 1862, Rept. Geol. Survey Wisconsin, vol. 1, fig. 2, p. 21. (No text reference.)

Lingula pinneformis Owen, Hart, 1862, idem, p. 435, fig. 3, p. 21. (Discussed.)

Lingula antiqua Emmons, Haypen, 1862, Am. Jour. Sci., 2d ser., vol. 33, p. 73, figs. la-b. (Discussed. It may be
that the Lingula prima here mentioned by Hayden was based on the dorsal valves of L. antiqua.)

Lingulepis pinnaformis (Owen), Hauu (in part), 1863, Sixteenth Rept. New York State Cab. Nat. Hist., pp. 129-
130, Pl. VI, figs. 14-16 (not figs. 12 and 13, referred to Obolus matinalis). (Described and discussed.)

Lingulepis pinniformis (Owen), Mprx and Haypen, 1865, Smithsonian Contrib. Knowl., No. 172, Paleontology
Upper Missouri, pp. 2-3, Pl. I, figs. la-b. (Described and discussed.)

Lingulepis dakotensis Mrnx and HaypEn, 1865, idem, p. 3. (Name merely proposed in case the species should prove
distinct.)

Lingulepis pinnaformis (Owen), Hatn (in part), 1867, Trans. Albany Inst., vol. 5, p. 107, Pl. I, figs. 14-16 (not
figs. 12 and 13, referred to Obolus matinalis). (Copy of Hall, 1863, p. 129-130.)

LInngulepis pinnaformis (Owen), WHITFIELD, 1880, U. S. Geog. and Geol. Survey Rocky Mtn. Region, Rept. Geology
and Resources Black Hills of Dakota, p. 335, Pl. II, figs. 14. (Described.)

Lingulepis dakotensis Meek and Hayden, Wurrrienp, 1880, idem, pp. 337-338, Pl. II, figs. 10 and 11. (Copies the
description given by Meek and Hayden, 1865, p. 2, and discusses species. Figs. 10 and 11 are copied from
Meek and Hayden, 1865, Pl. I, figs. 1b and 1a, respectively.)

Lingulepis pinnaformis (Owen), WHITFIELD, 1882, Geology of Wisconsin, vol. 4, pp. 169-170, Pl. I, figs. 2and 3. (De-
scribed.)

Lingulepis pinniformis (Owen), Dwreut, 1886, Proc. Am. Assoc. Ady. Sci. for 1885, p. 208. (Mentioned.)

Lingulepis pinniformis (Owen), Hain and CuarKe, 1892, Eleventh Ann. Rept. State Geologist New York for 1891,
figs. 237 and 238, p. 232; and Pl. I, figs. 16 and 17. (Mentioned. Figs. 237 and 238 are outline drawings of
the figures given by Hall, 1863, Pl. VI, figs. 16 and 15, respectively; figs. 16 and 17 (PI. I) are copied from Hall,
1863, Pl. VI, figs. 16 and 15, respectively.)

Lingulepis pinniformis (Owen), Hatt and CiarKe, 1892, Forty-fiith Ann. Rept. New York State Museum for 1891,

figs. 237 and 238, p. 548. (Mentioned. Figs. 237 and 238 are copied from those on p. 232 of the preceding |

reference.

Lingulepis ty (Owen), Hatt and CrarKs, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, figs. 22
and 23, p. 60, and PI. I, figs. 35 and 36. (Mentioned on pp. 60 and 61. Figs. 22 and 23 are outline drawings
and figs. 35 and 36 are copies of the figures given by Hall, 1863, Pl. VI, figs. 16 and 15, respectively. )

Lingulepis pinniformis (Owen), ScaucuErr, 1897, Bull. U. 8. Geol. Survey No. 87, p. 260. (Questions specific
reference. )

Lingulepis pinniformis (Owen), GRABAU and Surmer, 1907, North American Index Fossils, vol. 1, p. 193, fig. 227.
(Described. The two figures in figure 227 are copied from Hall, 1863, Pl. VI, figs. 15 and 16.)

Lingulepis prima (Hall), GraBav and Sumer, 1907, idem, p. 193. (Described, but no figures are given, and it is
impossible to tell whether the species should be referred to Lingulella (Lingulepis) acuminata or to Lingulella
prima.)

General form elongate ovate, with the ventral valve subacuminate to acuminate, and the
dorsal valve ovate in outline. The outline of the valves varies greatly (PI. XL). On a single
slab of rock from Whitehall, New York, there is a range of variation that unites the slender
acuminate form, represented by figure 1c, with forms that are not to be differentiated from
Lingulella acutangula (Roemer). The range of variation in the dorsal valve is less, but it
varies from elongate ovate to nearly round ovate. The convexity of the valves varies with the
size and condition of preservation. Those that preserve the natural convexity are rather
strongly convex in the dorsal valve, and about one-third less so for the associated ventral valve.
The variation in size is very marked, large groups of shells occurring where the average leneth
of the ventral valve is not over 6 to 10 mm. In other localities this creases to 20 mm. with
corresponding increase in width.

Surface marked by concentric lines of growth, very fine concentric strie, and fine radi-
ating strie. When the outer layer of the shell is exfoliated, the surface is marked by flattened,
radiating striz and concentric lines and striz of growth. The inner surface is marked by flat-
tened radiating striz and minute pits or puncte.

The shells from most localities are relatively thin, but some from the locality at St.
Croix Falls show several layers, and those from the sandstones of the Black Hills of South

—"

—

OBOLIDA. 547

Dakota are relatively strong and thick. The shell is built up of a thin outer layer and several
inner layers or lamelle that, on the anterior and lateral portions of the shell, are oblique to
the outer layer and form a thick, laminated shell very much like that of Obolus. Casts of the
interior of the ventral valve show a clearly defined area that extends a considerable distance
forward along the cardinal slopes. It is divided midway by a strong, rather broad pedicle —
furrow, and about midway of the very narrow side spaces, by extremely narrow flexure lines.
One specimen from the Black Hills shows that the area formed a thin shelf between the pedicle
groove and the lateral margins, the undercut extending some little distance beneath it. The
area of the dorsal valve is clearly marked in a few specimens; it is relatively short although
fairly well extended on the lateral margins.

The cast of the visceral cavity (v) is rarely preserved except in its posterior portion; this
is marked by the cast of a median groove, and the path of advance of the central, anterior
lateral, and middle lateral muscle scars. Traces of the muscle scars or the anterior portion
of the visceral cavity are rarely preserved; thus the heart-shaped pit so often seen in Lingu-
lella and Obolus is outlined in not over a half dozen specimens out of several hundred casts of
the interior. The position and shape of the visceral area varies with the width of the shell.
In the long shells it extends far forward, while in the broad shells it scarcely reaches to the
center (PI. XLII, figs. le and 1g.) No traces of a median septum have been observed in the
ventral valve, but in the dorsal it is shown in the casts as a narrow, clearly defined, sharp
depression, extending from between the anterior lateral scars back and between the central
muscle scars.

The muscle scars are more or less clearly shown in a number of casts of both valves. The
umbonal scar of the ventral valve is divided as in Obolus, the pedicle scar (m) (Pl. XLII, fig. 1g)
being situated between the two parts (gg). In the dorsal valve the umbonal scar is situated
just in front of the area, arching slightly toward the beak. The scars of the central, anterior
lateral, and middle lateral muscles are not clearly defined in the ventral valve, owing to their
bemg crowded together in the space on each side of the anterior portion of the visceral cavity.

The central muscle scars of the dorsal valve are of medium size and well defined on a number
of casts of the interior of the shell. They are situated a little back of the center of the shell
on each side of the median ridge, and their longer axis is slightly inclined outward. The anterior
laterals are not well defined in the ventral valve, because they are crowded into a very narrow
space. On the dorsal valve they are rarely visible, owing to their very faint impression on
the shell. The transmedian scars are distinctly shown on the dorsal valve, but in the ventral
valve they have not been differentiated from the anterior laterals.

The markings left on the shell by the vascular system are limited to the main or trunk
sinuses on a few casts of the interior (Pl. XLI, fig. 1a, and Pl. XLII, fig. 1e).

Observations.—The type specimens described by Conrad [1839, p. 64] were small, and from
an uncertain locality in the ‘‘Calciferous sandrock.’’ His associate, Mr. Vanuxem, states
[1842, p. 35] that Doctor Hights found a rolled stone containing L. acuminata, the surface of the
fractured part showing from 60 to 70 valves in an area 2 by 3 inches.

I have collected this species in situ in great numbers in Saratoga County, and in the valley
of the Hudson near Whitehall, in calcareous sandstones probably equivalent to Conrad’s
“Calciferous sandrock.” The shell corresponds to the description given by Conrad, and occurs
in great numbers in partings of the rocks.

Tn all of the illustrations given of this species from New York, the small, relatively narrow
form was figured. The broader and larger form that occurs in the compact, sandy limestone
north of Saratoga Springs, and at Beverly, Ontario, does not appear to have been known to
the earlier authors.

It was not until 1863 that the Hastern forms so much like those of ‘‘Lingula pinnaformis”’
of Wisconsin were illustrated by Billings [1863, p. 102]. Matthew [1895b, Pl. II] illustrated
the interior of the ventral and dorsal valves of Z. (L.) acuminata from Beverly, Ontario. The
muscle scars and their markings, as shown in Matthew’s diagrammatic figures, vary from those

548 CAMBRIAN BRACHIOPODA.

I have observed, and none of the specimens studied by him showed the area of either the ventral
or dorsal valve.

As the result of a comparison of a series of specimens of L. (L.) acuminata from the Potsdam
sandstone and the base of the ‘“‘Calciferous” in Saratoga, Washington, Franklin, and Jefferson
counties, New York, and from the same horizon in Ontario, Canada, with a large series of
specimens from the ‘‘St. Croix sandstone” of Wisconsin, I was led [1897a, p. 404] to conclude
that “Lingula pinnaformis” Owen was a synonym of Lingulella (Lingulepis) acuminata (Con-
rad), thus making L. (L.) acwminata the type of the subgenus Lingulepis, the original description
of the subgenus being based upon specimens from the “‘St. Croix sandstone” of Wisconsin.

It is hardly practicable to illustrate all of the varieties of L. (L.) acuminata (Conrad) as
they occur in widely distributed localities. The shells appear to have varied in size, thickness,
convexity, and outline at various localities, and often in the same locality in different layers,
probably owing to the character of food supply and the vitality of the individual animals.
Very fine specimens of the casts of young shells of the narrow, elongate form occur at Mount
Washington, Kau Claire, Wisconsin.

The species ranges from western Vermont, New York, and eastern Canada, westward across
the upper Mississippi Valley to the Black Hills of South Dakota, the Bighorn Mountains of
Wyoming, and the Rocky Mountains of central Colorado. In the Appalachian region it ranges
southward to Tennessee and Alabama, and westward to the Arbuckle and Wichita mountaims of
Oklahoma, and the Franklin Range near H] Paso, Texas. Its vertical range appears to have
been from the upper portion of the Middle Cambrian in the Mississippi Valley and the Black
Hills to the lower layers of the ‘‘Calciferous”’ of the Ordovician in New York and Canada.

A number of shells from the Upper Cambrian rocks of Nevada come within the rather wide
range of variation of this species. I was at first inclined to place them as a variety, but after
extended comparison with a series of specimens from New York and Wisconsin, decided that
nothing would be gained by so doing. A few figures on Plate XXXIV, figures 4, 4a-e, illus-
tgate the wide variation in form of the Nevada shell, a variation comparable with that from
the typical locality in New York.

A fine series of specimens illustrating the narrow and broad forms has been collected from
the limestone in the upper portion of the Reagan sandstone (Upper Cambrian), at the north-
west extremity of the Arbuckle Mountains, Oklahoma.

Dwight [1886, p. 208], in speaking of the Upper Cambrian fauna near Poughkeepsie, New
York, said:

It will be observed, as has been suggested to me by Whitfield, that the fauna of this locality forms a connecting
link between the Potsdam fossils of the Appalachian region and that of the more western States. Thus, the Lingulella

pinnaformis of Wisconsin and other western localities is here mingled with Lingulepis minima and acuminata of New
York State.

Dwight’s remark that the species “‘Lingulella pinnaformis” occurs mingled with “Lingu-
lepis minima” and “‘L. acuminata” proves that all the varieties of Lingulella (Lingulepis)
acuminata occur at the Dutchess County locality.

ForMATION AND LOCALITY.— Ordovician and Upper Cambrian: (338u) Strata from the upper layers of the Potsdam
sandstone to the lower portion of the ‘‘Calciferous sandrock” at Chateaugay Falls, Franklin County, New York.

Upper Cambrian: (392e [Billings, 1856, p. 34]) Sandstone on lot 22, ninth concession, township of Bastard; (392d
[Billings, 1856, p. 34]) sandstone on lot 11, eleventh concession, township of Lansdowne; and (392b [Matthew, 1895b,
p. 258]) sandstone (corresponding to the passage beds above the massive Potsdam sandstone at Chateaugay Walls) at
Beverly, township of Bastard; all in the county of Leeds, Ontario, Canada.

(392) Potsdam sandstone at Burgess; (892m) sandstone on the east shore of Missisquoi Bay, 1.5 miles (2.4 km. )
south of Phillipsburgh, Province of Quebec; and (392n) sandstone in eastern Canada (exact locality unknown); all in
Canada.

(16n) Interformational conglomerates and shales in Adams pasture, 0.5 mile (0.8 km.) west of Main Street, on
Lake Street, St. Albans, Franklin County, Vermont.

(76) Arenaceous limestone at Hoyt’s quarry, 4 miles (6.4 km.) west of Saratoga Springs, Saratoga County; (76a)
arenaceous limestone in a railroad quarry 1 mile (1.6 km.) north of Saratoga Springs, Saratoga Corea: (109) sandstone
25 feet (7.6 m.) above the Archean, 1.5 miles (2.4 km.) south of Deweys Bridge, on the Champlain Canal, Washington

OBOLIDA. 549

County; (367k) sandstone at Deweys Bridge, Washington County; (110 and 110a) shaly calcareous sandstone resting
on massive layers of Potsdam sandstone, east side of the town of Whitehall, Washington County; (338r [Billings,
1856, p. 34]) Potsdam sandstone at Keeseville, Essex County; (338s [Hmmons, 1842, pp. 267 and 268]) Potsdam sand-
stone at High Bridge, on Ausable River, Hssex County; (77) sandstone at several horizons in the section below
the falls at the high bridge, in Ausable Chasm, Essex County; (111) at the top of the Potsdam sandstone on
Marble River, 1 mile (1.6 km.) south of Chateaugay, Franklin County; (338t) Potsdam sandstone in Ausable Chasm,
below Keeseville, Essex County; (338w [Hall, 1847, p. 4]) Potsdam sandstone at Hammond, St. Lawrence County;
(338j [Hall, 1847, p. 4]) Potsdam sandstone near Alexandria Bay, Jefferson County; (185) sandy layers above the
massive Potsdam sandstone one-half mile (0.8 km.) southeast of Redwood, Jefferson County; (185a) sandy layers 20
feet above the massive Potsdam sandstone, east side of Indian View, 3 miles (4.8 km.) south of Theresa, Jefferson
County; -(367j) sandstone 3 miles (4.8 km.) south of Poughkeepsie, Dutchess County; (108) sandstone 1 mile (1.6 km.)
south of Poughkeepsie, Dutchess County; and (367e[ Dwight, 1886, p. 205]) shaly limestones 850 feet (259.1 m.) southerly
from the southwest corner of the driving park and 2,200 feet (670.6 m.) west of the road leading southerly from the
same, about 1 mile (1.6 km.) southwest of Vassar College, near Poughkeepsie, Dutchess County; all in New York.

(92b) Limestone on Buffalo Creek, 2 miles (3.2 km.) southeast of Buffalo Mills, Rockbridge County, Virginia.

(105) Limestone in Knox dolomite, at Bishops Mill, Hancock County; and (1070) limestones and shales at the
base of the Knox dolomite, west of the top of Copper Ridge, near the Southern Railway cut, about 10 miles (16.1 km.)
northwest of Knoxville [Keith 1896b, areal geology sheet], Knox County; both in Tennessee.

(79 and 79b) ‘‘St. Croix sandstone” near Hudson, St. Croix County; (82 and 82s) ‘‘St. Croix sandstone” on the
bank of St. Croix River, St. Croix Falls, Polk County; (328h) silicocalcareous layers of Flb of Owen, at the falls
of the St. Croix, Polk County; (97a) ‘“‘St. Croix sandstone” near Winfield, Jefferson County; (98) “St. Croix sand-
stone” near Hau Claire, Eau Claire County; and (99a) “‘St. Croix sandstone” near Pilot Knob, Adams County; all
in Wisconsin.

(330 [Hall, 1851, p. 204]) Sandstone on Taquamenon Bay, Chippewa County; (830b) sandstone at Iron Mountain,
Dickinson County; and (330a [ Hall, 1851, p. 204]) sandstone on Escanaba River; all in northern Michigan.

(339h [Hall, 1863, p. 130]) “‘St. Croixsandstone” near the mouth of the Minneiska (Miniska) River, near the line
between Wabasha and Winona counties; and (97b) “‘St. Croix sandstone” below the greensand bed and about 25
feet above St. Croix River at Franconia, Chisago County; both in Minnesota.

(353b) Sandstone just beneath the Ophileta zone, south end of the Franklin Range, El Paso County, Texas.

(360g) Shaly sandstone on Trout Creek, 1 mile (1.6 km.) below Manitou Park, El Paso County, Colorado.

(54d) About 1,050 feet (320 m.) above the Middle Cambrian and 175 feet (53.3 m.) below the top of the Upper
Cambrian in the lower part of the limestone forming 1 of the St. Charles formation [Walcott, 1908f, p. 192]; and (54g)
just above the Middle Cambrian, near the base of the bedded light-gray sandstone forming 4 of the St. Charles for-
mation [Walcott, 1908f, p. 193]; both in Blacksmith Fork Canyon about 10 miles (16.1 km.) east of Hyrum, Cache
County, Utah.

(7x and 7y) Limestone of the Emigrant formation [Turner, 1902, p. 265], about 2.5 miles (4 km.) southeast of
Emigrant Pass; and (7z) limestone of the Emigrant formation [Turner, 1902, p. 265], about 3 miles (4.8 km.) southeast
of Emigrant Pass; both in the Silver Peak quadrangle (U.S. Geol. Survey), Esmeralda County, Nevada.

(9q) About 10 feet (3 m.) above the porphyry contact and 90 feet (27.4 m.) below the Arbuckle limestone in
limestone of the Reagan sandstone, middle of west half of sec. 2, T. 4 N., R. 13 W., about 15 miles (24.2 km.) north-
west of Fort Sill, Comanche County; (9s) about 85 feet (26 m.) below the Arbuckle limestone in the limestone of the
Reagan sandstone, near middle of west half of sec. 13, T. 4 N., R. 13 W., 13 miles (20.8 km.) northwest of Fort Sill,
Comanche County; (9v) limestone of the Reagan sandstone, about 250 feet (76 m.) below the Arbuckle limestone,
SW. 4sec. 17, T.4.N., R. 12 W., about 11 miles (17.7 km.) northwest of Fort Sill, Comanche County; (12n) lime-
stone of the Reagan sandstone (in the section 7 miles (11.2 km.) north of Springer this horizon is about 240 feet
(73 m.) above the porphyry contact and 40 feet (12 m.) below the Arbuckle limestone), NW. } sec. 1, 7.2 S., R.1E.,
Ardmore quadrangle (U. S. Geol. Survey), Carter County; and (12p) about 225 feet (69 m.) above the igneous rocks
in the limestone of the Reagan sandstone, at the northwest extremity of the Arbuckle Mountains, about 4 miles
(6.4 km.) east of Homer, Carter County; all in Oklahoma.

(14b) Limestone on Cold Creek at north end of gorge opposite the north end of Sponge Mountain, 2 miles (3.2
km.) south of the San Saba County line in Llano County; (14r) sandstone in the iower part of the beds exposed on
Colorado River, 3 miles (4.8 km.) south of the northeast corner of Llano County; (69) limestone near Honey Creek,
Burnet County; and (70) limestone near Morgans Créek, Burnet County; all in Texas.

Middle Cambrian: (328e) “St. Croix sandstone” at St. Croix Falls, Polk County; and (79x) ‘“‘St. Croix sand-
stone” near the flour mill on Beaver Creek, north of Galesville, Trempealeau County; both in Wisconsin.

(84) “St. Croix sandstone” at Dresbach, opposite the mouth of Black River, Winona County; (84s) ‘‘St. Croix
sandstone” near Dakota, Winona County; (339j) sandstone between the lowest blue shale and the reddish calcareous
beds above, at Taylors Falls, Chisago County; and (389k) sandstone near Winona, Winona County; all in Minnesota.

(89) Limestone in Murphrees Valley, Blount County, Alabama.

(874d) Shale 2 miles (3.2 km.) north of Rotherwood; and (124a) shale (Nolichucky?) overlying the limestone
which rests on the Rogersville shale, on Big Creek, southeast of Harlan Knob, 4 miles (6.4 km.) northeast of Rogers-
ville [Keith, 1905, p. 4, and areal geology sheet]; both in Hawkins County, Tennessee.

550 CAMBRIAN BRACHIOPODA.

(355) Sandstones on Red Canyon Creek, southwest side of Black Hills; (355d) sandstone in the Black Hills;
(164) sandstone in the Deadwood formation jn the cliffs on the east side of the valley near Deadwood, Black Hills;
(167) sandstone beneath limestone and resting on the pre-Cambrian in a bluff 9 miles (14.4 km.) west of Custer,
Black Hills; and (355b) sandstone in the Deadwood formation on Castle Creek, west side of Black Hills; all in South
Dakota. ;

(171 and 171a) Sandstone in Big Goose Creek Canyon, Bighorn Mountains, west of Sheridan, Sheridan County;
(302m) middle of shale above lower sandstone on Billy Creek, in the Bighorn Mountains, Sheridan County; and (340c)
dark-red sandstone near the base of the Cambrian at Rawlins, Carbon County; all in Wyoming.

LAINGULELLA (LINGULEPIS) ACUMINATA MBEKI (Walcott).
Plate XLI, figures 2, 2a.

Lingulepis meeki Waucorr, 1897, Am. Jour. Sci., 4th ser., vol. 3, p. 405. (Described and discussed as below as a new
species.

Obolus ees acuminatus meeki Waxucorr, 1899, Mon. U. 8. Geol. Survey, vol. 32, pt. 2, p. 444, Pl. LX, figs.
land la. (Text copied from preceding reference. The specimens represented by figs. 1 and la are redrawn
in this monograph, Pl. XLI, figs. 2 and 2a, respectively.)

Obolus (Lingulepis) acuminata weeksi Waxcorr, 1905, Proc. U. 8. Nat. Mus., vol. 28, p. 333. (Merely used for Obolus
(LinGulepis) acuminata meeki by mistake in discussion of ‘‘ Obolus (Lingulepis) eros.’’)

Shell small, attenuate, marked by rather strong concentric lines and strize of growth,
and interrupted, irregular, radiating striz.

Ventral valve narrow, elongate, beak acuminate, rostral slopes long, nearly straight,
passing gradually into the curvature of the anterolateral margins, and posteriorly meeting
at a very acute angle; front strongly rounded. Length of valve, 8 mm.; width, 3.5 mm., the
widest portion being near the anterior extremity. Beak slightly upcurved, the longitudinal
median line straight or even slightly concave from the apex of the beak to the middle, where
it begins to slope gently to the frontal margin; transverse curvature very slight anteriorly,
more convex than the beak.

Dorsal valve more convex than the ventral, linguliform; beak depressed, bluntly rounded,
curving evenly and gradually to the semitruncate anterior margin.

Observations.—The interior markings of this shell have not been ascertained, but the
external characters are such as to make a reference to the subgenus Lingulepis more than
probably correct. The flat, acute-acuminate ventral valve with its elevated or retrorse beak,
which is not covered by the smaller dorsal valve, is characteristic of Lingulepis.

There is a form from Texas, probably identical with Lingulella perattenuata (Whitfield)
that might be mistaken for this variety, but it is an undoubted Lingulella and does not show
the external characteristics of Lingulepis. A comparison of Lingulella (Lingulepis) acuminata
meeki with the young ‘and narrow specimens of L. (L.) acuminata (Conrad) shows it to vary
from that species, the posterior rostral slopes of L. (L.) acuminata possessing a peculiar incury-
ing which is not shown in L. (L.) acuminata meekr.

After the publication of ‘‘Lingulepis meeki’’ [Walcott, 1897, p. 405] shells were collected
from the north end of the Teton Range, which showed that that form was very closely related
to L. (L.) acuminata. As all the Teton Range shells were quite small and the majority had
the characters of ‘‘Lingulepis meeki,” the latter was reduced to a variety of L. (L.) acuminata
[Walcott, 1899, Pl. IX, figs. 1 and 1a], and the Teton shells were included with those from the
Gallatin Range.

The varietal name was given in honor of Dr. F. B. Meek.

FORMATION AND LOCALITY.—Middle Cambrian: (802b) Limestones near Crowfoot Ridge, Gallatin quadrangle (U.S.
Geol. Survey), Yellowstone National Park; and (4e) limestones about 950 feet (289.6 m.) above the unconformable
base of the Cambrian in the divide at the head of Jackson Creek (locally known as Sheep Creek), a creek flowing into
Jackson Lake about 0.5 mile (0.8 km.) south of its northwest corner, Teton Mountains, Grand Teton quadrangle (U.S.
Geol. Survey), Uinta County; both in Wyoming. f

(4h) About 375 feet (114.3 m.) above the base of the Cambrian in limestone interbedded in the Flathead shales
of Peale [1893, p. 21], 1 mile (1.6 km.) north of the junction of East Gallatin and West Gallatin (Gallatin) rivers, 4
miles (6.4 km.) east-northeast of Logan, Threeforks quadrangle (U. 8. Geol. Survey), Gallatin County, Montana.

OBOLIDZ. 551

le LINGULELLA (LINGULEPIS) ACUMINATA SEQUENS Walcott.

Text figures 46A-B.

Glossina acuminata Hatt and CrarKe [not Conran], 1892, Eleventh Ann. Rept. State Geologist New York for 1891,
Pl. I, figs. 10 and 11. (No text reference.)

Lingula (Glossina) acuminata Hatt and CrarKeE [not (Conrap)], 1892, Nat. Hist. New York, Paleontology, vol. 8,
pt. 1, Pl. I, figs. 1 and 2. (No text reference. Figs. 1 and 2 are copied from Hall and Clarke, 1892a, Pl. I,
figs. 10 and 11, respectfully.)

Lingulella (Lingulepis) acuminata sequens Waucorr, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, p.72, Pl. VIII, fig. 4
(Characterized and discussed as a new variety. Fig. 4 is copied in this monograph as fig. 46A.)

This variety differs from Lingulella (Lingulepis) acuminata (Conrad) in being somewhat
less attenuate in 1ts ventral valve, and in having the cardinal slope of the ventral valve straight,
instead of gently incurved.

It occurs at a slightly higher geologic horizon than L. (L.) acuminata, in appears to be
a form derived from that species.

Judging from Hall and Clarke’s illustrations [1892a, Pl. I, figs. 10 and 11] they had rep-
resentatives of this variety of Lingulella (Lingulepis) acuminata and mistook them for the
form illustrated by Hall [1847, p. 9] as Lingula acuminata. That figure represents a typical
form of LZ. (L.) acuminata, and is not the variety illustrated by
Hall and Clarke in 1892.

~The specimens illustrated by Hall and Clarke are given as
from Saratoga County, New York, “‘Calciferous sandstone.”
The specimens which I have taken as typical of this variety
are from Division A of the Beekmantown limestone.

This form owes its varietal name to the fact that it is a

later representative of the species. A
FIGURE 46.—Lingulella (Lingulepis) acumi-
FORMATION AND LOCALITY.—Ordovician: (367c) Beekmantown limestone, nata sequens Walcott. A, Ventral valve
Division A; quarry near the northwest suburb of Ticonderoga, Hssex County, Showing nearly straight lateral slopes
Now aver (U. S. Nat. Mus. Cat. No. 53675a). B,
: Dorsal valve (U. S. Nat. Mus. Cat. No.

LINGULELLA (LINGULEPIS) EROS (Walcott). 53675b).

i ; The specimens represented are from Lo-
Plate XX XIX, figures 9 and 9a. cality 867¢ near Ticonderoga, New York.

: : Fig. 46A is copied from Walcott [1908d, Pl.
Obolus (Lingulepis) eros Waucort, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 333. VIII, fig. 4]. It represents the type speci-

(Described and discussed as below as a new species.) men.

Ventral valve elongate with rostral slopes gradually converging so as to form an acuminate
beak. Surface marked by fine concentric lines of growth and very fine, somewhat irregular,
concentric striz. Rather large scattered puncte occur on the interior surface.

This species is represented by fragments and two broken ventral valves; these indicate a
length for the ventral valve of from 7 to10 mm. It is allied to Lingulella (Lingulepis) acumi-
nata meeki * (Walcott) of the Middle Cambrian fauna of the Teton mountains of Wyoming.

FORMATION AND LOCALITY.—Middle Cambrian: (C7) Lower limestone member of the Kiulung group [Black-
welder, 1907a, pp. 37 and 39 (last list of fossils), and fig. 8a (bed 33), p. 29], 2.2 miles (3.5 km.) southwest of Yenchuang,
Sintai district, Shantung, China.

LInGUELLA (LINGULEPIS) ExIGUA (Matthew).
Plate XX XIII, figures 4, 4a; Plate XLIII, figures 1, la-z.

Obolus (Lingulepis) gregwa Waxcorr (in part) [not (Marrnew)], 1901, Proc. U. S. Nat. Mus., vol. 23, pp. 692-694.
(Described and discussed almost as on pp. 552-553, with the exception of the notes under “‘Observations,”’
which have been rewritten in this monograph. The following species were included in this reference: Lingu-
lella (Lingulepis) exigua, L. (L.) gregwa, Lingulella tumida, and L. atava.)

a Written ‘‘weekst”’ in the original description [Walcott, 1905a, p. 333] through mistake.

5d2 CAMBRIAN BRACHIOPODA.

Lingulepis starri var. MarraEw, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, pp. 193-197, Pl.
XIV, figs. 2a-c. (Gives an essential copy (rearranged) of the description given by Walcott, 1901, pp. 692-694,
and describes and discusses the specimens referred by Walcott to Obolus (Lingulepis) gregwa as belonging to
an undetermined variety of Matthew’s ‘‘ Lingulepis starrt.’’)

Lingulepis starri exigua MatrtHEw, 1903, idem, pp. 197-198, Pl. XIV, figs. 3a-d. (Described and discussed as a new
variety.)

General form elongate ovate with the ventral valve acuminate and the dorsal valve ovate
triangular in outline. The outline of the valves varies, as shown by the series of figures on
Plate XLIII and by many other specimens not illustrated. The convexity of the valves varies
with the condition of the preservation, those from the sandstone being rather strongly convex,
while those in the shale are very much compressed. On the dorsal valve of the youngest
shells there is a marked and rather broad, shallow smus extendmg from the umbo to the front
where it flattens out.

One of the largest ventral valves has a length of 21 mm., with a width of 18 mm. A
dorsal valve 16 mm. in width has the same length; other examples are a little wider than long.

Surface of the shell marked by concentric strize and undulations of growth, over which
there is a series of very fine, elevated, sharply undulating and imosculating Imes that form a
minute irregular network over the surface, very much lke that of Lingulella (Lingulepis)

gregwa (Matthew), except that the irregular limes are very much finer on the latter. Where ~

the lines are strongly elevated the effect is that of a minutely granulose surface. In some

examples the surface suggests an incrusting or scabrous outer layer of shell covered with

-

minute points. When the thin outer layer of the shell is exfoliated the surface of the various
bright, shmy, inner layers is minutely granulose, im addition to the flattened, radiating striz
and concentric Imes of growth. The interior surface of both valves is often marked by con-
centric rows of strong pits or puncte very much as in Lingulella davisi (McCoy) (Pl. XX XI,
fig. 6g). In some specimens the lines of punctz extend over the surface of the visceral cavity
so as to obscure the vascular markings and muscle scars. Jn some examples only a few scat-
tered punctze occur, while in others they are present over nearly the entire surface. The small
shells are thin, but the larger ones are built up of a very thin outer layer and several inner
layers or lamellz that are more or less oblique to the outer surface, especially over the anterior
and lateral portions of the shell.

The plane of the cardinal area of the ventral valve is nearly coincident, near its edges, with
the edge of the shell. The area is long and extends well forward on the cardinal slope. It is
divided midway by a narrow, rounded, deep pedicle furrow, and about half way between the
pedicle furrow and the lateral margins by an unusually well-defined flexure lme which is in
line with the main vascular furrows of the interior of the valves; fine striz of growth cross the
area and arch around the pedicle furrow parallel to the base of the area. There is practically
no undercut beneath the area except near the flexure line at the frontal margin of the area.
The area of the dorsal valve is short, narrow, and crossed by fine lines of growth parallel to
its base.

The cast of the visceral cavity in the ventral valve shows it to have been relatively small
and usually confined to the posterior half of the shell, although in some shells it extends past
the center (Pl. XLIII, fiz. 1q). There are no traces of a median septum in the ventral valve; in
the dorsal valve, at the bottom of the groove between the central muscle scars, there is a slightly

elevated median line that extends forward to the anterior margin of the visceral cavity beyond -

the anterior lateral muscle scars. The visceral cavity of the dorsal valve usually extends
forward to about the center of the valve, but in a series of specimens collected in 1903 a number
of interior casts show the front of the visceral area varying in position from back of the center
to nearly the frontal margin of the shell; it varies in width and outline very much as the shells
vary, bemg wide in broad shells and narrow in elongate forms.

The markings left on the shell by the vascular system are very strong and beautifully pre-

served in some portions. The direction and size of the maim sinuses are well shown by the
illustrations; in some shells there is a double groove with a slight ridge between; in others the

OBOLID. 553

ridge is large, only a trace of an outer groove remaining; in some young shells the groove is
broad and shallow; in all shells the large size of the main vessels is shown by the broad, strong
grooves or ridges left on the shell. It frequently happens that the lines of sharply defined pits
on the lines of growth deeply dent the grooves and rounded ridges left by the main vessels
and mark them off to sections. The interior and lateral vessels left narrow but strong grooves
or ridges on the shell, which, however, are usually obscured by the strong pitting of the surface.
The parietal scar surrounds the visceral cavity in each valve, crosses the course of the main
vascular vessels, and comes back around the spaces occupied by the muscle scars, terminating
at the edge of the area at the flexure lme in the ventral valve; termination unknown on the
dorsal valve.

Some of the muscle scars are finely shown in the dorsal valve and fairly well in the ventral.
The umbonal scar of the ventral valve is divided, the pedicle scar being situated between the
two parts. In the dorsal valve the umbonal scar is close to the area, and extends nearly as far
each side of the median line as the length of the area.

The scars of the central muscles in the ventral valve are crowded in with the acta and
outside laterals within the trapezoidal space (c, Pl. XIII, figs. 1q and 1s). In the dorsal
valve they are located on a low ridge each side of a central, longitudinal median depression;
they are elongate oval in outline, their major axis being subparallel to the median line of the
shell; fine longitudinal lines cross the scars in the best preserved specimens; the ridge on which
the central scars occur varies in strength, but it appears to be present im all adult shells; it
narrows gradually posteriorly and rather rapidly to the imner side of the anterior lateral muscle
sears. The anterior laterals of the ventral valve are placed well back on the narrow space
between the edge of the area and the main vascular sinus; they are elongate and rather large;
in the dorsal valve they are elongate with the major axis inclining toward the median line (Pl.
XLII, figs. lr and ly). The middle and outside laterals are situated in the trapezoidal area
(c) of the ventral valve, but neither is clearly separable from the other or from the central
scars. In the dorsal valve the position of the middle and outside laterals is shown, but not
their form or size. The transmedian scars in the ventral valve are seen just back of the anterior
laterals, but they have not been observed in the dorsal valve owing to the imperfections of the
shell.

Observations.—This is one of the most interesting species of Lingulepis I have known. In
its coarsely pitted inner surface it recalls Lingulella davist (McCoy) (Pl. XX XI) of England, and
Obolus willis (Walcott) (Pl. XXIII) of the southern Appalachians. The elongate ventral
valve is like that of Lingulella (Lingulepis) acuminata (Conrad), while the interior scars and
markings are those of Obolus. With L. (L.) gregwa (Matthew) and L. (Z.) starri (Matthew) it is
the Atlantic coast representative of L. (Z.) acuminata which is so abundant in the Middle
Cambrian of the Upper Mississippi Valley, and in the passage beds between the Cambrian and
the Ordovician in the region adjoining the Adirondack Mountains of New York. It differs
from L. (L.) acuminata in its surface characters.

The shells embedded im the fine-grained shales are all flattened and more or less distorted by
compression, while those in the sandy layers interbedded in the shales retain their original
convexity, although frequently distorted and fractured by movement of the matrix. The
fracturing of the brittle, mineralized shell is beautifully illustrated by Plate XX XIII, figure
4a, which represents the siliceous fillings of the fractures, the shell substance having been
dissolved with acid.

Typical specimens of Lingulella (Lingulepis) exigua have narrow, elongate ventral valves and
broadly oval dorsal valves. I was at first strongly mclined to separate the broad, thick shells
as a, distinct species, but on finding a series of connecting forms and observing that the surface and
interior markings were similar, I decided to unite them. The shells vary materially in their
external aspect in the different Javan of siliceous rock, but when the shell substance is removed
by acid it is found that their interior and exterior ghomeaiens are the same. The typical forms ~
of L. (L.) exigua are represented in Plate XLIII, by figures 1, la—b, 1d, 1g—-j, and the variations

554 CAMBRIAN BRACHIOPODA.

by figures 1f, lo-s. With growth in size and age the shell increases in thickness notably over the
posterior portions.

In some notes [1901, p. 692] on “Lingulepis gregwa”’ (Matthew), I identified this shell as
“Obolus (Lingulepis) gregwa.” It.is closely related to it but differs in the surface characters.
The exterior shell of Lingulella (Lingulepis) gregwa is marked by fine, irregular, elevated, and
sometimes inosculating ridges that have a row of minute tubercles on them that give a beaded
appearance to each ridge. The surface of the shell of L. (L.) exigua has a much more minutely

granulose surface formed by very irregular, inosculating, elevated lines or ridges, much like .

that of L. (L.) robertt (Matthew).

Matthew [1903, p. 193] refers this form to “Lingulepis starri var.” With the types of
starri as a basis of comparison I find that the type of surface of starri is as stated by Matthew
[1891, p. 147]: ‘‘Each valve is ornamented by numerous, concentric furrows, closely set, about
12 to 15 to a millimeter.” I find 8 to 10 on one of the typical specimens. This surface is quite
unlike the surface of LZ. (L.) exigua which is as described above. When the thin outer layer is
exfoliated the concentric striz and ridges of growth are like the surface of starrz, but the outer
surface is roughened (‘‘granulated,’’ Matthew) in a manner unlike the surface of L. (L.) exigua.
It has the appearance under a strong magnifier of a surface produced by fine points distributed
over an incrusting layer of shell.

ForMATION AND LOCALITY.—Upper Cambrian: (8n) Thin-bedded sandstone on Salmon River, Gillis Hill, 13 miles
(20.9 km.) south of Marion Bridge, eastern Cape Breton, Nova Scotia.

Middle Cambrian: (3i) Compact, fine-grained, thin-bedded, gray sandstone of the Paradoxides zone [horizon of Division
C2b, Matthew, 1903, p. 195], on McLean Brook, 1 mile (1.6 km.) east of McCodrum Brook and 1.5 miles (2.4 km.) west
of Marion Bridge; (10s and 10t) sandstone on McLean Brook, near Marion Bridge; (307f [Matthew, 1903, p. 198]) shale
of Division 62a on McLean Brook, Mira River; (307g [Matthew, 1903, pp. 195 and 198]) shales of Division C2b on
McLean Brook, Mira River; (18r) sandstone of the ‘‘Johannian’’ Division of Matthew’s section on Gillis Brook, East
Bay, east of Bras d’Or Lake; and (11z) sandstone on Big Ridge, 2 miles (3.2 km.) south of Marion Bridge, on the
canal of John McDougald; all in eastern Cape Breton, Nova Scotia. ‘cb

LINGULELLA (LINGULEPIS) GREGWA: (Matthew).

Plate XLIV, figures 1, la—p.

Tingulella gregwua Matruew, 1899, Bull. Nat. Hist. Soc. New Brunswick, vol. 4, pp. 199-200, Pl. I, figs. laf. (De-
scribed and discussed as a new species.)

Obolus (Lingulepis) gregwa Watcort (in part), 1901, Proc. U. S. Nat. Mus., vol. 23, pp. 692-694. (The following
species were included under Lingulella (Lingulepis) gregwa in this reference; Lingulella (Lingulepis) exigua,
L. (L.) gregwa, Lingulella twmida, and L. atava. The specimens upon which the description was based are now
referred to Lingulella (Lingulepis) exigua.

Lingulepis gregwa MatrHEew, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, pp. 56-57. (Notes
on orientation of shells.)

Lingulepis gregwa Matranw, 1903, idem, pp. 126-131, Pl. TX, figs. 3a-f. (Described and discussed. Figs. 3a-f are
copied from Matthew, 1899, Pl. I, figs. la-t.)

The description of Lingulella (Lingulepis) exigua (Matthew) applies very closely to this
species, with the exception of the surface characters and details of outline, and the interior

markings of the valves. As a whole, the ventral valve of L. (L.) gregwa is less acuminate,

and the outline of the dorsal valve is more rounded posteriorly. A comparison of the series
of illustrations of the two species fully exhibits the differences referred to. The exterior sur-
face of the shell of Z. (Z.) gregwa is marked by a few, strong, concentric lines of growth, and

numerous fine, concentric, irregular, often inosculating ridges having a row of minute tubercles”

on them that gives a beaded appearance to each ridge. This appearance is unmistakable when
the outer shell is at all well preserved. There are also indications of very fine radiating ridges,
irregularly dispersed over the surface of the shell. When the thin, highly ornamented outer
layer is exfoliated the various lamelle of the shell show very fine, radiating strie, and a few
concentric lines of growth. The interior of the shell has rather large scattered puncte, and
occasionally a specimen shows the punctz gathered in concentric lmes. The shell is built up
of a thin outer layer and several mner layers, or lamell, that are more or less oblique to the

saith aa

OBOLIDZ. 5D5

outer surface, especially over the anterior and lateral portions of the shell, where they are
much more numerous. In many specimens the shell substance has been replaced by calcite.
Interiors of the ventral valve show considerable difference in the position of the main
vascular sinuses. They are usually well out toward the sides. In the dorsal valve the main
vascular sinuses are widely separated, and the visceral area is well extended toward the

front.
Observations—When studying the collections made by 8. Ward Loper on McLean Brook

in 1900, I identified the shells now placed under Lingulella (Lingulepis) exigua as “ Obolus (Lin-
gulepis) gregwa.”’ But at that time I had only the somewhat imperfect material in Matthew’s
collection from Dugald Brook for the purposes of comparison. With a large series of well-
preserved specimens collected on Dugald Brook im 1901 by Loper, the fact that the two species
had been confused became at once apparent. Lingulella (Lingulepis) gregwa is found in great
numbers at a lower stratigraphic horizon beneath the Paradoxides zone, while L. (L.) exigua
occurs at the summit of the Middle Cambrian fauna in association with Paradozides. Both
species have strong points of resemblance to L. (Z.) acuminata (Conrad) and both, in their
younger stages, depart to such an extent from the typical forms of the adult shell that they
micht be considered a distinct species if found at another locality or stratigraphic horizon.
The specific name is derived from Gregwa Brook, on which specimens of the species occur.
FORMATION AND LOCALITY.—Middle Cambrian: (10p) Sandstone just below the waterfall in Division E2b of
Matthew’s [1903, p. 21] Etcheminian, on Dugald Brook, Indian River; (10p’) sandstone one-fourth mile (0.4 km.)
from lower bridge, on Gregwa Brook, Indian River; (10p’”) sandstone on the small brook on the hill between the
bridge over Indian River and McPhees Brook; (18t’’) sandstones of Divisions Elec and Eld of Matthew’s [1903, p. 21]
Etcheminian, on Dugald Brook, Indian River; (344¢ [Matthew, 1903, p. 78]) shales of Division Eld of Matthew’s
[1903, pp. 28 and 29] Etcheminian, on Boundary Brook, eastern side of the Escasonie Indian Reservation; (344k4
[Matthew, 1903, p. 77]) sandstones of Division Elb of Matthew’s [1903, p. 21] Etcheminian, on Dugald Brook, Indian
River; (344m | Matthew, 1903, p. 78]) sandy shales of Division E1d of Matthew's [1903, p. 21] Etcheminian, on Dugald
-Brook, Indian River; and (344n [Matthew, 1903, p. 33]) shales in the gorge at the old millon McCodrum Brook, Mira
River; all in eastern Cape Breton, Nova Scotia.

_— LAINGULELLA (LINGULEPIS) GREGWA ROBUSTA (Matthew).

Lingulepis gregwa robusta MartHEW, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, p. 57. (Notes
on orientation of shells.)
Lingulepis gregwa robusta Matthew, 1903, idem, p. 131. (Characterized as a new variety.)

Matthew separates a form with a thicker shell and straighter cardinal margins as the
variety robusta. My impression is that these characters are so largely the result of the con-
dition of preservation of the specimens in the matrix that the variety has very little value.

FORMATION AND LOcALITY.—Middle Cambrian: (10p) Sandstone just below the waterfall in Division E2b of Matthew’s
[1903, p. 21] Etcheminian, on Dugald Brook, Indian River; (10p’) sandstone one-fourth mile (0.4 km.) from lower
bridge, on Gregwa Brook, Indian River; (10p’’) sandstone on the small brook on the hill between the bridge over
Indian River and McPhees Brook; (18t’”) sandstones of Divisions Ele and Eld of Matthew’s [1903, p. 21] Etche-
minian, on Dugald Brook, Indian River; (344h [Matthew, 1903, p. 79]) sandy layers in the shales of Division Ele of
Matthew’s [1903, p. 21] Etcheminian, on Dugald Brook, Indian River; and (344m [ Matthew, 1903, p. 78]) sandy shales
of Division Eid of Matthew's [1903, p. 21] Etcheminian, on Dugald Brook, Indian River; all in eastern Cape Breton,
_Nova Scotia.

LIncGuLELLA (LINGULEPIS) LONGINERVIS (Matthew).

Plate XLIV, figures 2, 2a-¢.

Lingulepis longinervis MarrHEw, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, pp. 133-135, Pl.
\ VII, figs. 6a-g. (Described and discussed asa new species. The specimen represented by figure 6f is redrawn
in this monograph, Pl. XLIV, fig. 2e.)

This species diiiers from Lingulella (Lingulepis) gregwa (Matthew) in having the sides of
the ventral valve extended in a nearly straight line beyond the center of the valve. Some of
Matthew’s specimens have a concentrically striated surface with only a trace of the character-
istic surface of L. (L.) gregwa. Others show more of the ornamented surface, and in specimens

@ Doubtfully identified from this locality.

556 CAMBRIAN BRACHIOPODA.

collected by S. Ward Loper from the same beds from which the types of L. (L.) longinervis
came, the surface is indistinguishable from that of L. (Z.) gregwa.

Matthew [1903, p. 134] considers the long, large ‘‘visceral callus” of the dorsal valve as the
most prominent characteristic of this form. I find in L. (L.) gregwa (Matthew) and L. (L.)
exigua (Matthew) that the visceral area in many specimens extends nearly to the front of the
dorsal valve and that the length and strength of the visceral area in both ventral and dorsal
valves of Lingulepis are not usually characters to be depended upon as criteria for specific
determinations. The position assigned to the central and anterolateral muscle scars by Matthew
[1903, Pl. VII, figs. 6e and 6f] appears to be theoretical, as a most careful study of the typ-
ical specimens fails to locate them as indicated in the figures. In fact, the specimens are too
poorly preserved to indicate clearly where the scars are. Fine casts of the interior collected
by Loper show the scars named farther toward the central portion of the shell.

Lingulella (Lingulepis) longinervis differs from L. (L.) exigua (Matthew) im its less atten-
uate ventral valve and less robust character in both size and thickness of shell.

The specimens collected by Matthew are small and do not show the variation that exists
in the collection made by Loper: In a layer of reddish brown sandstone Loper found a great
number of shells varying in size and form from those similar to Matthew’s types to shells nearly
twice as large. Ina layer of hard gray standsone, 5 feet above, all the specimens are similar in
size and form to those collected by Matthew. Lingulella triparilis (Matthew) occupies a
position intermediate in form between L. (L.) gregwa (Matthew) and L. (L.) longinervis, and
the surface characters of the three species are essentially of the same type.

ForRMATION AND LOCALITY.—Middle Cambrian: (372f) shales of unknown stratigraphic position; (18d/’) sand-
stones 10 feet (3 m.) below Division E2a; (13g) sandstones 10 feet (3 m.) above Division E2a; (18f) sandstone 20 feet
(6 m.) above Division E2a; (13p and 18p’) sandstones 40 to 45 feet (12.2 to 13.6 m.) above Division H2a; (13d) sand-
stones opposite the third waterfall in Dugald Brook, between Divisions H2a and E2b; (10p) sandstones just below the’
waterfall, in Division E2b; (3440 [| Matthew, 1903, p. 134]) sandstones of Division £2b; and (181) shaly sandstones of
Division E3a; all in Matthew’s [1903, p. 21] Etcheminian, on Dugald Brook, Indian River, eastern Cape Breton, Nova
Scotia. : vig
(10p’) Sandstone one-fourth mile (0.4 km.) from lower bridge, on Gregwa Brook, Indian River; and (10p’’) sand-
stone on the small brook on the hill between the bridge over Indian River and McPhees Brook; both in eastern Cape
Breton, Nova Scotia.

LINGULELLA (LINGULEPIS) PUMILA (Matthew.)

Plate XLV, figures 3, 3a.

Lingulepis pumila MarraEew, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, p. 75, Pl. VII, figs.
5a and 5b. (Described as a new species. The specimens represented by figs. 5a and 5b are redrawn in this
monograph, Pl. XLV, figs. 3 and 3a, respectively.)

This species differs from Lingulella triparilis (Matthew) and Lingulella (Lingulepis) greqwa
(Matthew) in having a more attenuate ventral valve. In this respect it resembles the narrow
forms of L. (L.) longinervis (Matthew). The material is poor, so that only the general form
can be used to characterize it. One dorsal valve shows that the shell was thick, very much as
in L. (L.) exigua (Matthew). The surface of exfoliated shells is nearly smooth. Matthew
[1903, p. 75] describes the outer surface as consisting of irregular concentric ridges, about six in
the space of a millimeter.

ForMATION AND LOCALITY.—Middle Cambrian: (344f [Matthew, 1903, p. 72]) Shales in the Coldbrook terrane of

Matthew, on Dugald Brook, Indian River, eastern Cape Breton, Nova Scotia.

Specimens that are somewhat doubtfully referred to this species occur at the following
loeality:

Middle Cambrian: (18k) Shales of Matthew’s [1903,p. 15] Coldbrook, above the great fall in Dugald Brook, Indian

River, eastern Cape Breton, Nova Scotia.

LINGULELLA (LINGULEPIS?) PyGMaA (Salter).
Plate XXX, figure 10.

Lingula pygmxa SaurER, 1865, Quart. Jour. Geol. Soc. London, vol. 21, p. 102, figs. 8a and 8b, p. 101. (Described asa
new species; see p. 557 for copy. Figs. 8a-b are copied in this monograph, Pl. XXX, fig. 10.)

OBOLID®. NA

Lingula pygmzxa Salter, Davipson, 1866, British Fossil Brachiopoda, vol. 3, pt. 7, No. 1, p. 53, Pl. Il, figs. 8 and 8a.
(Text and figures copied from the preceding reference.)

Lingula pygmea Salter, Purures, 1871, Geology of Oxford and the Valley of the Thames, p. 68, Diagram XVII, fig. 13.
(No text reference.)

Lingula pygmxa Salter, Marrey, 1902, Quart. Jour. Geol. Soc. London, vol. 58, p. 141. (Synonymy given and species
mentioned.)

The original description by Salter follows:

Minute, subcylindrical, gibbous; beak somewhat obtuse; anterior margin truncate; shell thin; surface finely
striated transversely. Length, 7; inch; width, ;, inch. In the Black shales.

The Black shales are referred to the Upper Cambrian, the locality being in the eastern por-
tion of the Malvern Hills of England. Davidson [1866, p. 53] states that he could only repro-
duce Salter’s description and figure, as he had not seen specimens of the shell. The figure given
by Salter [1865, figs. 8a and 8b, p. 101] is that of an elongate, cuneate shell more like the typical
form of Lingulepis than Lingulella. From its form and the fact that it occurs in association
with the Olenus fauna it is probable that it should be referred to Lingulepis.

FORMATION AND LOCALITY.—Upper Cambrian: (304f [Salter, 1865, p. 102]) ‘‘Black shales’’ in the Malvern Hills,
between Herefordshire and Worcestershire, England.

LINGULELLA (LINGULEPIS) ROBERTI (Matthew).

Plate XX XVII, figures 4, 4a-d.

Lingulella roberti MattHEW, 1895, Trans. Roy. Soc. Canada for 1895, 2d ser., vol. 1, sec. 4, No. 13, pp. 256-257, Pl. I,
figs. 2a and 2b. (Described and discussed as a newspecies. Plate XX XVII, figs. 4, 4a-d of this monograph are
drawn from specimens in Matthew’s type material, and it is possible that the specimens represented by figs. 4a
and 4b are the ones figured by Matthew, figs. 2a and 2b, respectively, but positive identification is impossible.)

Lingulepis roberti MattHEw, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, p. 132, Pl. VIII, figs.
5a-b. (Text and figures copied from the preceding reference.)

General form elongate ovate, with the ventral valve acuminate and the dorsal round ovate.
The cardinal slopes of the ventral valve are in some shells slightly incurved as in Lingulella
(Lingulepis) acuminata (Conrad) ; a portion of this curvature, as shown in Plate XX XVII,
figures 4 and 4a, may be owing to the lateral compression of the shells. The convexity of the
soninal valve is moderate, le that of the dorsal is unusually large (Pl. XX XVII, fig. 4b).
This may be owing to the deformation of the shell by lateral pressure in the matrix.

Surface of the shell marked by very fine, obscure, radiating striz and narrow undulations,
and very fine, irregular, concentric striz between relatively strong strie and lines of growth.
The irregular striz inosculate, Plate XX XVII, figure 4c, so as to give an appearance much
like that of Obolus ( Westonia) ella (Hall and Whitfield) (Pl. XLVII, fig. 10). When the thin
outer layer is exfoliated, the dark shiny surface of the inner layers shows radiating strie and
concentric lines of growth. The inner surface appears to have been punctate to a moderate
degree. The shell is moderately thick and is built up of a thin outer layer and several inner
layers or lamelle that anteriorly are slightly oblique to the outer layer, much as in Lingulella
acutangula (Roemer).

The largest ventral valve among the type specimens has a length of 13 mm.; width, 9
mm.; the width is narrowed 2 or 3 mm. by the lateral compression. A dorsal valve that
is very little, if any, distorted is 10 mm. long and 10 mm. wide. A trace of the pedicle groove
in the ventral valve is shown by Plate XX XVII, figure 4a. The area of the dorsal valve is
not preserved in any of the specimens sent to me by Matthew.

The cast of the visceral cavity is shown in Plate XX XVII, the ventral valve in figure
4a and the dorsal valve in figure 4b.

The anterior lateral and central muscle scars are seen in the specimens of the type sent
me by Matthew. In g and h, figure 4b, of Matthew’s figures, the umbonal scar is short and
broad, as in Obolus selwyni (Matthew) (Pl. XX XVII, fig. 14).

The markings of the vascular system observed are the main vascular sinuses of the ventral
valve, a trace of them in the dorsal valve, and a little of the parietal scar about the visceral
cavity im the dorsal valve (fig. 4b).

558 CAMBRIAN BRACHIOPODA.

Observations.—This species is related by its form to Lingulella (Lingulepis) greqgwa (Mat-
thew) and L. (L.) longinervis (Matthew), but it differs in its surface characters. In its very
fine, irregular striz and general form it is closely allied to ZL. (L.) exigua (Matthew). The
thick, robust shell and numerous strong pits on the inner surface of the shell give the latter
a character not seen in L. (L.) robert.

The visceral area and muscular scars of the ventral and dorsal valves are much like those
of Obolus selwyni (Matthew) (Pl. XX XVII), and in specimens of the same size occupy relatively
the same position. The specific variations between the two species appear to be in the shape
of the valves and the character of the finer ornamentation of the surface.

Matthew originally [1895, p. 257] referred this species to the Ordovician fauna, but in
his review of the Cambrian fauna of Cape Breton [1903, p. 132] it is referred to his lower
Ktcheminian.

The specific name was given in honor of Mr. J. Alfred Robert, of the Geological Survey of
Canada, who collected the specimens of the species.

ForMATION AND LOCALITY.—Middle Cambrian: (307d [Matthew, 1903, p. 132]) Sandy limestone of Division E2a?
of Matthew’s Etcheminian, on Young (McFees) Point [Matthew, 1903, p. 19], near George River station, Cape Breton,
Nova Scotia.

LINGULELLA (LINGULEPIS) ROWEI (Walcott).

Plate X XI, figures 4, 4a—b.

Obolus (Lingulepis) rowei Waxcort, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 334. (Characterized as a new species.)

This shell differs from Lingulella (Lingulepis) acuminata (Conrad) and other species of
Lingulella and Lingulella (Lingulepis) im the sharp, fine, concentric ridges of the outer surface,
about six to the millimeter. This surface resembles closely that of Obolus (Palzobolus) bre-
tonensis Matthew. The material is not well preserved, but there is sufficient to illustrate the
form of the valves and the character of the surface. A fragment shows a more attenuate
posterior portion of a ventral valve than the one illustrated.

The specific name is given in memory of Mr. R. B. Rowe, assistant geologist of the
United States Geological Survey, who collected the material a short time before his death.

ForMATION AND LOCALITY.—Lower Cambrian: (14p) Reddish-brown quartzitic sandstone, near Resting (Fresh-

water) Springs, which is in the southwest corner of T. 21 N., R. 8 E., on Amargosa River, in the southeastern part
of Inyo County, California.

LINGULELLA (LINGULEPIS) SPATULA (Walcott).
Plate XIX, figures 5, 5a—-b.

Obolus (Lingulella) spatulus Waucort, 1902, Proc. U.S. Nat. Mus., vol. 25, p. 607. (Described and discussed as below
as a new species.)

General form of the ventral valve spatulate, the sides sloping from the apex forward with

a very slight curvature to the anterior fifth of the shell, where they pass into the broadly —

rounded frontal margin.

Dorsal valve ovate with the greatest width toward the front. Convexity moderate, and
about equal in both valves. A ventral valve 9 mm. in length has a convexity of about 1 mm.
A fragment of the outer surface indicates that the surface was relatively smooth, being broken
only by fine, scattered strie of growth. The inner layers show concentric lines, also fine,
radiating strie. The interior of the shell was marked by scattered pustules, concentric striz,
and a few radiating lines.

The largest ventral valve has a length of 9 mm. and a width of 6 mm. A dorsal valve
5 mm. in width has a length of 7 mm.

The only trace of the vascular system preserved is the median ridge of the dorsal valve,
which extends forward to the anterior fourth of the shell.

Observations.—This very pretty little shell occurs in abundance in the chocolate brown
sandstone interbedded in the shales, just above the massive ‘“‘Tonto’’ sandstone. It is distinct

OBOLID. 559

from all other species known to me from the Cambrian rocks of the Grand Canyon region.
Obolus ( Westonia) chuarensis (Walcott) occurs in a layer of sandstone 50 or 60 feet higher up
in the section.

FoRMATION AND LOCALITY.—Middle Cambrian: (74d) Sandstone beds in ‘‘Tonto’’ shale just above massive

sandstones near mouth of Bass Canyon, on the south side of the Grand Canyon of the Colorado, southeast of Powells
Plateau, Arizona.

LINGULELLA (LINGULEPIS?) sQUAMOSA (Holl).
Plate XXX, figure 9.

Lingula squamosa Hott, 1865, Quart. Jour. Geol. Soc. London, vol. 31, pt. 1, p. 102. (Described as a new species;
see below for copy.)

2 Lingula squamosa Holl, Davipson, 1866, British Fossil Brachiopoda, vol. 3, pt. 7, No. 1, p. 41, Pl. II, fig. 7. (Copies
the original description and discusses species. Fig. 7 is copied in this monograph, Pl. XXX, fig. 9.)

The original description by Holl follows:

Triangular, broad anteriorly, compressed; beak acute; anterior margin truncate; shell thick, strongly grooved
from side to side by imbricating lines of growth. Length, one-fourth inch. In the light-brown felspathic sandstone
of the Hollybush series.

The sandstone of the Hollybush series is beneath the Black shales in which Lingulella
(Lingulepis?) pygmza (Salter) occurs, but appears to form a portion of the Upper Cambrian
of the Malvern Hills section. The species has a peculiar cuneate form, more like that of ZL. (Z.)
acuminata (Conrad) than any other European shell known to me. On this account it is
referred to the subgenus Lingulepis.

FORMATION AND LOCALITY.—Upper Cambrian: -(304g [Holl, 1865, p. 102]) Sandstones of the Hollybush series,
Malvern Hills, between Herefordshire and Worcestershire, England.

LINGULELLA (LINGULEPIS) STARRI (Matthew).
Plate XX XVII, figures 2, 2a—b.

Lingulella starri MartHEw, 1891, Trans. Roy. Soc. Canada for 1890, Ist ser. vol. 8, sec. 4, No. 6, pp. 146-147, Pl. XV,
figs. 5a-c, 6a-b. (Described and discussed as a new species. According to Matthew the type specimens have
been mislaid or lost, and the specimens represented in this monograph are from new material collected by him.)

Tingulepis starri Martarw, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, p. 195. (Mentioned.)

General form cuneate, elongate ovate, with the ventral valve obtusely acuminate and the
dorsal valve broadly ovate; valves appear to have been moderately convex. Outer surface
of the shell marked by fine, concentric, slightly irregular striz, 8 to 12 in the space of a milli-
meter; when the outer layer of shell is exfoliated coarser concentric strie are seen; and on
the inner surface of the shell strong concentric striz and numerous radiating strie occur, the
latter being most prominent on the anterior half of the valves. The shell is strong and is built
up of a thin outer layer and several inner layers or lamelle, very much as in Lingulella acutan-
gula (Roemer). : :

A large ventral valve, as measured by Matthew, has a length of 16 mm.; width, 14 mm.

A east of the interior of a broken ventral valve shows the visceral cavity (v) and a trace
of the main vascular sinus (Pl. XX XVII, fig. 2b).

Observations.—This is one of the large species of the genus and compares in this respect
with Lingulella ampla (Owen) and Obolus ( Westonia) aurora (Hall). Matthew wrote me that
the type of this species had been mislaid or lost. The illustrations are taken from other speci-
mens identified and labeled by him.

The specific name was given in honor of Mr. R. P. Starr, who discovered the species.

FoRMATION AND LOCALITY.—Upper Cambrian: (308¢ [ Matthew, 1891, p. 147]) Shales of Division 2b of Matthew's
Johannian at St. John; and (2x) thin-bedded sandstones of Division 2 of Matthew [1892, p. 59], on the south shore
of Long Island, Kennebecasis Bay [Matthew, 1898a, pp. 124 and 127]; both in St. John County, New Brunswick.

560 CAMBRIAN BRACHIOPODA.

LineuLetia (LINGULEPIS?) sp. undt. (Walcott).

Obolus (Lingulepis) sp. undt. Waxcorr, 1906, Proc. U. 8. Nat. Mus., vol. 30, pp. 567-568. (Characterized as below
as an undetermined species. )

This species is represented by a few fragments, one of which shows that the ventral valve
is elongate, and the apex acuminate. The shell was built up of several layers or lamellz, as
in characteristic forms of Lingulella (Lingulepis). The interior surface of some of the lamellee
is marked by fine, radiating, and concentric strie; the outer surface, under a strong magnifier,
shows fine, concentric, somewhat irregular strie.

ForRMATION AND LOCALITY.—Middle Cambrian: (C72) Thin green-gray limestone interbedded with ocherous and

green clay shales, overlying the massive oolite in the Kichou formation [Willis and Blackwelder, 1907, pp. 139 and
145 (8d list of fossils)], 4 miles (6.4 km.) east of Fanglanchon, Shansi, China.

Genus DELGADELLA Walcott.

Delgadella Waxcort, 1908, Smithsonian Misc. Coll., vol. 53, No. 4, Pl. XI, and pp. 142 and 144. (Classification of
genus.)

The description of the type species includes all that is known of this genus. The form
of the shell is more like that of Lower Ordovician species referred to Lingula than to the typical
forms of Lingulella or Lingulepvs.

Type.—Lingulepis lusitanica Delgado.

The generic name is given in memory of the late Mr. J. F. Nery Delgado, of the Geological

Survey of Portugal.
DELGADELLA LUSITANICA (Delgado).

Plate X XIX, figures 5, 5a-b.

Lingulepis lusitanica Detcapo, 1904, Communicagoes Commissio Servico Geologico Portugal, tome 5, fasc. 2, pp.
365-366, Pl. IV, figs. 31-34. (Characterized and discussed in French as a new species. Photographs of the
specimens represented by figs. 31, 32, and 34 are reproduced in this monograph, Pl. X XIX, figs. 5a, 5b, and 5,
respectively, each individual figure being a reversed view of Delgado’s original figure.)

General form elongate ovate, moderately convex. The greatest width of the ventral
valve is at the anterior third, whence the outline narrows slightly to the broadly rounded front,
and gradually to the subacuminate posterior half.

Dorsal valve unknown, unless Plate IV, figure 17, and possibly figure 27, of Delgado,
represents it. However, these two shells are referred in this monograph to Lingulella delgadoi
(p. 491) as they appear to be more closely related to that species than to Delgadella lusitanica.

Shell thick and with a thick margin. This is shown by the casts of the edges of the valves,
as shown by figures 5 and 5a. Shell substance unknown. Delgado [1904, p. 365] states that
the shells range from 5 to 8.5 mm. in length.

Observations.—Delgado referred this species to Lingulepis on account of its general form,
but from the fact that it has a thick, strong shell and does not have the attenuated extension
of the apex of the ventral valve of the typical forms of Lingulepis I am inclined to refer it to
a new genus characterized by a thick shell, spatulate form, with a subacumimate beak. A
shell agreeing with this in outline and form occurs in the Lower Gudlomneem shales at Kelleys
Island, “Clmeapiion Bay, Newfoundland.

Welendo [1904, p. 365] compares this species with the very young shells of Lingula lesuewrt
Rouault foavikem, 1866, Pl. I, figs. 1-11]. If the specimens representing it had been sent
to me without any information as to the associated fauna, I should have been strongly inclmed
to refer them to a Lower Ordovician fauna.

LIangulella (Lingulems) acuminata meeki (Walcott) has a somewhat similar outline, but
that is a thin, corneous shell of the Upper Cambrian fauna. We must await further discoy-
erles of more perfectly preserved material before a more complete description can be given.

a Prior to the definition of the genus Delgadella the type species was described under Lingulepis [Delgado, 1904, p. 365].

OBOLIDA. 561

Mr. Delgado very kindly sent me a specimen of this species, also some large photographs
of specimens illustrated by him. I have reproduced three of these in illustration of the species.

FORMATION AND LOCALITY.—Lower Cambrian: (351 [Delgado, 1904, p. 365]) Shales at Monte de Valbom, north-
east of Villa Boim, Province of Alemtejo, Portugal.

Subfamily ELKANIIN4 Walcott and Schuchert.

Genus ELKANIA Ford.

Billingsia Forp [not Dz Kontncx, 1876], 1886, Am. Jour. Sci., 3d ser., vol. 31, pp. 466-467. (Described and discussed
as a new genus.)

Not Billingsia Waxcort, 1886, Bull. U. S. Geol. Survey No. 30, pp. 5, 21, 60, and 62. (Used in lists for a genus of the
Gastropoda.) °

Elkania Forp, 1886, Am. Jour. Sci., 3d ser., vol.32, p. 325. (Proposes Elkania for Billingsia, which was preoccupied.)

Elkania Ford, Hari and CrarKe, 1892, Eleventh Ann. Rept. State Geologist New York for 1891, p. 241. (Described.)

Elkania Ford, Hatt and CrarxKe, 1892, Forty-fifth Ann. Rept. New York State Museum for 1891, p. 557. (Copy of
preceding reference.)

Elkania Ford, Har and CrarKe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt: 1, pp. 75-78. (Copies part of
Billings’s, 1861b, p. 70, description of “‘Obolelia desiderata” and Ford’s, 1886a, p. 467, description of the genus,
and describes and discusses genus.) ;

Elkania Ford, Waxcorr (in part), 1905, Proc. U. 8. Nat. Mus., vol. 28, pp. 321-323. (Described and discussed essen-
tially as below. The text includes reference to species now placed under Obolus (Fordinia).)

Elkania Ford, Watcorr, 1908, Smithsonian Misc. Coll., vol. 53, No.4, Pl. XI, and pp. 142 and 144, (Classification of
genus.)

General form ovate, biconvex; shell substance corneous and made up of several thin layers
or lamellz that crease in number toward the front and lateral margins. Surface marked by
fine concentric strize of growth. Apex of both ventral and dorsal valves marginal. The inte-
rior of the ventral valve has a thickened posterior section which has a central pedicle furrow
and two flexure lines running obliquely forward and outward from the apex, a little inside of
the grooves of the main vascular trunks; this structure is apparently the result of the union of
the area with the bottom of the shell so as to bring, as the shell grew, the path of advance of the
pedicle groove, main vascular sinuses, and lateral muscle scars all on one surface instead of on

the area and the shell beneath it as m Obolus.

The muscle scars are arranged as in Obolus. The transmedian and anterior laterals occur
well out toward the margin (Pl. LI, fig. 1) and the space inclosing the central, middle lateral,
and outside lateral scars is in the central area, on the front of the slope of the thickened posterior
portion of the valve (Pl. LI, figs. 1 and 3a); the points of attachment of the individual muscles
can not be distinguished. In ‘the dorsal valve the central and anterior lateral scars are clearly
shown in sane specimens; the transmedian and outside laterals are situated just outside
the main vascular sinus (Pl. LI, fig. 1c). Our knowledge of the vascular markings is limited to
the main vascular sinuses, except in one ventral valve, where the inner branches have been
preserved; in both valves the main trunk rises near the apex and its path is outlined across the
internal cardinal area.

The preceding description differs materially from that of Ford [1886a, p. 467] and Hall and
Clarke [1892c, p. 77]. I find the muscle scars as described above and am compelled to consider
them as indicating the same muscles as in Obolus. That the genus is an advance on Obolus in the
evolution of the inarticulate brachiopods I quite agree with Hall and Clarke [1892¢, p. 165], but
not that it is a stage in the transition from Obolus to Trimerella and its allies. (See reine
on platform, p. 309.) Elkama is an Obolus with the cardinal areas within the plane of the
margins of the valves. In the type species, H/kania desiderata (Billings), the area of the ventral
valve is entirely within the valve, while that of the dorsal valve has been nearly obliterated
in the process of change from an open backward-facing area to an inclosed forward-facing

«The synonymy for this genus does not give a complete record of the various genera under which the species now included in Eikania were
formerly placed; it gives only those references in which the genus is discussed or described. To complete the record the following mere generic
references are listed:

Oboleila Billings [1862d, pp. 69 and 71]. Obolella ? Walcott [1884b, p. 67; 1886b, p. 111].
Obolella Davidson [1868, p. 309].

62667°—vo1 51, pr 1—12-—36

562 CAMBRIAN BRACHIOPODA.

area. A comparison of the interiors of Obolus apollinis Kichwald (PI. VII, figs. 1-17) with those
of Obolus (Fordinia) bellulus (Walcott) (Pl. LI, figs. 3a-f) and Elkania desiderata (Billings) (PI.
LI, figs. 1, 1a-d) illustrates how little change is necessary to convert the exterior cardinal areas
of Obolus into the inclosed mternal areas of Hlkania.

As the beaks of Elkania are marginal, the pedicle passed out through an opening made by
the gaping of the valves.

The three known species of the genus are the type species Hlkania desiderata (Billings), E.
ambiqua (Walcott), in which the shell is very thick, and #. ida (Billings).

Authors have referred frequently to the resemblance between species of Obolella and Elkania
desiderata. This does not appear to exist except in a superficial manner. Obolella is a stage
in the evolution toward the Siphonotretide, whereas Elkania has no known descendants.

The generic name was given in honor of Dr. Elkanah Billings, of the Geological Survey of
Canada.

ELKANIA AMBIGUA (Walcott).

Plate LI, figures 2, 2a-c.

Obolella ? ambigua Waucott, 1884, Mon. U.S. Geol. Survey, vol. 8, pp. 67-68, Pl. I, figs. 2a-c. (Described and discussed
as a new species. The specimens represented by figs. 2a—c are redrawn in this monograph, Pl. U1, figs. 2a, 2, and
2b, respectively.)

Billingsia ? ambigua (Walcott), Forp, 1886, Am. Jour. Sei., 3d ser., vol. 31, p. 467. (Generic relations mentioned.)

Elkania ambigua (Walcott), Forp, 1886, idem, vol. 32, p. 325. (Merely changes generic reference.)

Elkania ambigua (Walcott), Hatt and CrarKe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, p. 78.
(Generic relations discussed.)

General form ovate; biconvex; beaks marginal. Surface marked by fine concentric striz
of growth. Substance of shell corneous as far as can be determined, although some of the
layers appear to be calcareous. The shell is made up of many thin layers or lamelle.

Ventral valve elongate oval, moderately convex. Dorsal valve transversely broad ovate;
the interior shows a slender median septum at the bottom of a shallow, concave, well-defined
visceral area; within the latter area the central muscle scars occur at the outer margins about
one-half the distance from the posterior margin to the anterior margin of the visceral area;
the anterior lateral scars are close together on each side of the median septum at the anterior
margin of the area; the thickening of the shell varies greatly in different shells; in some it
extends far to the front (Pl. LI, fig. 2c) and im others it is scarcely noticeable (fig. 2b).

No interiors of the ventral valve have been found and the cardinal area of the dorsal valve
is unknown. The largest dorsal valve has a length of 9 mm.; width, 10 mm.

This species in size and form is related to E. desiderata (Billings) ; it differs in the character
of the interior of the dorsal valve, and in having a thicker and stronger shell in the adult stage.

When the species was first described its relations were uncertain, hence the specific name.

ForRMATION AND LOCALITY.—Lower Ordovician: (63) Base of the Pogonip limestone, northeast of Adams Hill; and

(202) Pogonip limestone, on the summit of the ridge directly southeast of the Jackson mine, northwest of Shadow
Canyon; both in the Eureka district [Hague, 1892, Atlas], Eureka County, Nevada.

ELKANIA DESIDERATA (Billings).

Plate LI, figures 1, la-d.

Obolella desiderata Bruines, 1862, Geol. Survey Canada, Paleozoic Fossils, vol. 1, pp. 69-70, figs. 62a—b. (Described
and discussed as a new species. The specimens represented by figs. 62a and 62b are redrawn by Hall and
Clarke, 1892c, Pl. III, figs. 16 and 17, respectively.)

Obolella desiderata Billings, Davipson, 1868, Geol. Mag., vol. 5, figs. 1 and 2, p. 309. (Mentioned.)

Obolella? desiderata Billings, Watcortt, 1886, Bull. U. S. Geol. Survey No. 30, p. 111. (Generic relations discussed.)

Billingsia desiderata (Billings), Forp, 1886, Am. Jour. Sci., 3d ser., vol. 31, pp. 466 and 467, fig.1,p.466. (Generic
relations discussed.)

Elkania desiderata (Billings), Forp, 1886, idem, vol. 32, p. 325. (Merely changes generic reference.)

Elkania desiderata (Billings), Haut and CirarKe, 1892, Eleventh Ann. Rept. State Geologist New York for 1891, Pl.
III, figs. 13 and 14. (No text reference. Figs. 13 and 14 are drawn from casts of the two specimens figured
by Billings, 1862d, figs. 62a and 62b, p. 68, the specimens themselves being redrawn in Hall and Clarke, 1892c,
Pl. III, figs. 16 and 17, respectively.)

—-

OBOLID®. 563

Eilkania desiderata (Billings), Hari and CrarKn, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, pp. 76 and
77, Pl. III, figs. 15-19. (Part of original description, Billings, 1862d, p. 70, copied on p. 76 and species described
and discussed. Figs. 16 and 17 are drawn from the specimens figured by Billings, 1862d, figs. 62a and 62b,
p. 68; figs. 15 and 18, which represent casts of the specimens represented by figs. 16 and 17, respectively, are
copied from figs. 13 and 14 of the preceding reference.)

The species has been so thoroughly described by Billings [1862d, p. 69], Ford [1886a, p. 466],
and Hall and Clarke [1892c, p. 77], from their respective points of view, that I will confine my
observations to the interior characters. As noted under the genus, I regard the cardinal areas
as being reversed; that is, sloping within the plane of the margins of the valves instead of with-
out, as in Obolus; the space beneath the area and the bottom of the valve is filled with shell,
and the margin of the area thus disappears in the anterior slope of the thickened portion of
the shell. |

The scheme of muscle scars, as far as they are known, is the same as in Obolus. In the
ventral valve the anterior laterals (j) and transmedians (i) occur outside the main vascular
sinuses toward the margin of the valve and in front of the included cardinal area. The space
occupied by the central and middle and outside lateral scars is defined on the front slope of the
umbonal thickening of the valve. The muscle scars of the dorsal valve include the transme-
dian and outside laterals on the outer margin of the main vascular sinuses, and the central
and anterior laterals on the margins of the central visceral area.

The vascular markings include the main vascular sinuses in the two valves, and some
inner branches in the ventral valve.

Elkania desiderata differs from EL. ambigua (Walcott), the only related species, in the interior
of the dorsal valves, which are the only parts we have for comparison. The shell is also
thinner.

FORMATION AND LOcALITY.—Lower Ordovician: (319a) Levis shales, Point Levis, Province of Quebec, Canada.

ELKANIA IDA (Billings).
Plate XXX, figures 20, 20a; Plate LI, figures 4, 4a-c.

Obolella ida Brxtines, 1862, Geol. Survey Canada, Paleozoic Powis, vol. 1, p. 71, fig. 63a-b. (Described and dis-

cussed as a new species, see below for copy.) :
Obolella? ida Billings, Watcorr, 1886, Bull. U. 8. Geol. Survey No. 30, p. 111. (Generic relations mentioned.)
Billingsia ? ida (Billings), Forp, 1886, Am. Jour. Sci., 3d ser., vol. 31, p. 467. (Generic relations mentioned.)
Elkania ida (Billings), Forp, 1886, idem, vol. 32, p. 325. (Merely changes generic reference.)

The original description by Billings follows:

Shell small, obtusely ovate, greatest width at or a little in front of the middle, abruptly narrowed to the beaks,
sides and front margin uniformly rounded, the front slightly less convex than the sides. Both valves equally and
rather strongly convex, most elevated at about one-third the length from the apex, thence sloping with a gentle curve
to the sides and front margin, abruptly descending on each side of the beak and umbones. Ventral valve slightly
more pointed above than the dorsal; umbo narrowly convex; beak apparently depressed to the level of the lateral
margin. Dorsal valve obtusely angular or narrowly rounded at the beak, the latter not visibly distinct from the
cardinal edge; umbo obtusely convex. Surface with a somewhat shining aspect, with very fine concentric striz;
a few radiating striz are visible on two of the specimens. Shell apparently very thin.

Length of a perfect ventral valve, 2 lines; width, 1f lines. The length and width of the dorsal valve are about
equal.

In some material from the McGill University Museum, kindly lent to me by Sir William
Dawson and Dr. Frank D. Adams, I found some fine specimens labeled Obolella ida, collected
by J. Richardson. These specimens show the characters described by Billings [1862d, p. 71]
and in addition the following: The shell is corneous and built up of many lamelle or layers
arranged obliquely to the surface so as to form a thick, strong shell. The interior of the ventral
valve has a thickened umbonal portion with a pedicle groove much like that in E. desiderata
(Billings), but much shorter in proportion; owing to the imperfect condition of the remaining
portions, no further details can be determined. The interior of the dorsal valve shows a
thickened elevated area like that of the dorsal valve of H. desiderata (Pl. LI, fig. 1d), but differ-
ently shaped. A large transverse depression just in advance of the posterior margin appears

564. CAMBRIAN BRACHIOPODA.

to be all that is left to indicate the cardinal area; the central muscle scars are situated just
in advance of this depression and the anterior laterals at the front end of the visceral area; the
position of the transmedian and outside lateral scars is indicated by an elongate scar near
the posterolateral margin, just in advance of the traces of the cardinal area. Vascular markings
unknown.

This species differs from £. desiderata in having a thicker and more convex shell and has
a differently shaped visceral area in the dorsal valve.

FORMATION AND LOCALITY.—Lower Ordovician: (319)@ Limestone No. 1 of Billings’s section; and (319i) limestone
of Billings’s section; both at Point Levis, Province of Quebec, Canada.

Subfamily NEOBOLIN® Walcott and Schuchert.
Genus NEOBOLUS Waagen.
[béoc, young; and Obolus.

Neobolus WAAGEN, 1885, Mem. Geol. Survey India, Paleontologia Indica, 13th ser., Salt Range Fossils, vol. 1, pt. 4;
fas. 5, pp. 756-758. (Described and discussed as a new genus. )

Davidsonella WAAGEN [not Munier-CHauMas, 1880], 1885, idem, pp. 762-764. (Described and discussed as a new
genus. )

Neobolus Waagen, OnnuERt, 1887, Manuel de conchyliologie, by Fischer, p. 1263. (Described in French, with figures
of Neobolus warthi.)

Lakhmina Onuert, 1887, idem, p. 1265. (Described in French, with figures of ‘‘ Lakhmina linguloides.’’)

Lakhmina Oehlert, Waaczn, 1891, Mem. Geol. Survey India, Paleontologia Indica, 13th ser., Salt Range Fossils,
vol. 4, pt. 2, description of Pl. II, figs. 3-4. (No text reference.)

Lakhmina Oehblert, Hatt and CrarKe, 1892, Eleventh Ann. Rept. State Geologist New York for 1891, pp. 234-235.
(Described. )

Neobolus Waagen, Hatt and CirarKks, 1892, idem, p. 245. (Described.)

Lakhmina Oehlert, Hatt and CrarxKs, 1892, Forty-fifth Ann. Rept. New York State Museum for 1891, pp. 550-551.
(Copy of Hall and Clarke, 1892a, pp. 234-235.)

Neobolus Waagen, Hatt and CrarKe, 1892, idem, p. 561. (Copy of Hall and Clarke, 1892a, p. 245.)

Lakhmina Oehlert, Hatt and Crarxke, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, pp. 28-30. (Described
and discussed.)

Neobolus Waagen, Hatt and CnarKe, 1892, idem, p. 84. (Described and discussed.)

Neobolus Waagen, Watcort, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, pp. 72-76. (Described and discussed as
below, with the exception of the paragraph describing the two text figures.) F

Neobolus Waagen, Watcorr, 1908, idem, vol. 53, No. 4, Pl. XI, and pp. 142 and 144. (Classification of genus.)

General outline of shells broad oval to subcircular; nearly equivalve, moderately convex.
Shell substance caleareocorneous and probably phosphatic, structure laminated. Surface with
concentric striation. Shell strong for its size and built up on its anterior and lateral margins
of several thin layers or lamellae. Apex of ventral valve small and shghtly projecting over a
low false area that appears to have an open delthyrium. Apex of dorsal valve marginal.

The interior of the ventral valve has a strong, rounded, central ridge extending from
the narrow area, about one-third the length of the shell, and a strong ridge on each side that
extends from the same point of origin as the central ridge obliquely forward nearly to the ~
frontal margin of the shell;’ between the central ridge and the posterior portions of the lateral
ridges there are slightly concave shelves forming, with the central ridge, a triangular platform,
with an open space beneath the concave shelves; numerous radiating strize occur on the con-
cave shelves and the inner surface of the shell.

Of the muscular impressions in the ventral valve, Waagen wrote [1885, p. 762] that
“nothing can be observed.’ Considered from the point of view of the Trimerellidz, this
may appear to be correct, but if we compare the muscle scars of Obolus with what appear to
me to be points of attachment of muscles in the specimen represented by Plate LX XXI, figure
2e, there is no difficulty in recognizing a few scars. Just beneath the outer extension of the
narrow area of the ventral valve there is a minute, clearly defined, elongate, oval space that
corresponds to the divided umbonal muscle scar in Obolus apollinis Kichwald; near the outer

a@This is the locality from which the species is listed in the collections of the Geological Survey of Canada. Billings [1862b, p. 71) also identifies
the species from No. 2 of his section. Y
bI do not find any indication of the incurving of these ridges as described and illustrated by Waagen [1885, p. 762, Pl. LX XXV, fig. 6].

OBOLID/. 565

margin, on a line with the anterior portion of the central ridge, there is a narrow elongate
space which, under a strong reflected light, is seen to be divided diagonally by a slight, narrow,
raised line. Compared with Obolus this space is the point of attachment of the transmedian
and anterior lateral muscle scars. It is probable that the outside and middle lateral muscle
scars and the centrals were attached to the platform, but there are no defined muscle scars
upon it.

The interior of the dorsal valve has several very unusual characters. There is no true
cardinal area, unless the thick margin of the shell be considered as such; from the center of
the cardinal margin a strong flat process marked by concentric lines of growth projects forward
into the valve and rises a little above the plane of the margin of the valve. Waagen [1885,
p- 763] calls attention to the resemblance between this process and the tooth of .Trimerella
lindstrémi. From beneath the median process a short, thick platform projects upward and
forward into the valve (Pl. LXXXI, figs. 2f, 2g, and 2h); it is as wide as the process at its
base, expanding toward its front margin. It is concave between its lateral crests, and the
outer slopes are slightly concave from the crest to the body of the shell; in front the concave
- space and crests terminate rather abruptly above the front face, which in turn is underlain
by a transversely hollow space of unknown extension beneath the platform. Toward each
end of the frontal area a minute depression appears to indicate the point of attachment of
a muscle. A narrow, rounded median septum extends from beneath the platform well toward
the front of the shell. Two more or less interrupted and obscure ridges, indicating the main
vascular trunks, extend from the front anterolateral angles at the base of and at the side of
the platform obliquely outward into the valve. The elongate smooth spaces outlined by
Waagen [1885, Pl. LX XXV, fig. 6] in his illustrations of this valve are too indefinite to be
given form in the drawing of the only specimen showing the interior. What appears to be
a small muscle scar occurs at the cardinal angle; it corresponds in position to the transmedian
sear of Obolus.

Figure 47A, page 567, shows Abe area, median ridge, and side ridges of the visceral area of the
dorsal valve. The “llsyhtoaran shown by Plate LXXXI, Beaune 2f, has not been developed beyond
the first stages of its growth. Itis probable that the fully dewalomed platform occurs only in
very old shells. There is no trace of a platform in the specimen represented by Plate I, figure
3, but it may have been broken away. In another shell, not illustrated, there is no trace of
thickening beneath the visceral area. In a section of the platform, median ridge, and vas-
cular sinuses taken where they unite with the inner surface of the dorsal valve (fig. 47B, p. 567)
the platform appears to be intermediate in development between the platforms represented by
figure 47A, page 567, and Plate LX XXI, figure 2f.

Type. —Mecbalus warth, Waagen.

Observations—Through the courtesy of Dr. T. H. Holland, Finecian of the Geological
Survey of India, I received the type specimens of Neobolus, Dawiaeonala, and Lakhmina,
studied, dsscrtinadl, and illustrated by Waagen. With these Thallowe me I find that the slvhanaie
figures of Waagen [1885, Pl. LXX XV] are diagrammatic to a considerable extent, also that
I can not clearly recognize some of the characters noted by Waagen.

Waagen’s original description [1885, p. 762] of the genus ‘‘ Davidsonella”’ is very full and
he also gives a detailed description of the type species ‘‘D. linguloides.” Ochlert [1887, p.
1265] evidently based his description of ‘‘Zakhmina” on Waagen’s description and illustra-
tions, apparently not noting that Waagen stated in his text [1885, p. 762] that the elongate
area on the sides of the interior of the shell were not muscle scars, but that he considered them
as smooth areas outside the crescent.

Oehlert [1887, p. 1265], when describing the genus Lakhmina, says, “with a straight and
projecting beak perforated for the passage of the foramen.” He reproduces Waagen’s figures
and shows a deep pedicle furrow. This leads me to think that he had Waagen’s description
and figures in mind when writing his diagnosis of Lakhmina. Only one shell shows the apex
of the ventral valve and the small false area beneath, and one other of the interior shows the
true area and a triangular depressed spot at the center; a fracture at the center has broken

566 CAMBRIAN BRACHIOPODA.

out a bit of the shell which gives rise to the narrow, deep furrow described by Waagen. The
ventral valve has (a) a false area beneath the apex, and (b) a true area on a plane with the
margins of the valve.

When looking over the types of Neobolus and Lakhmina for the purpose of having illus-
trations made of them, I noted that there was a strong resemblance between the anes. of the
two genera, but having the impression that the sentinel valve of Lakhmaina had a pedicle open-
ing at the apex, drawings were arranged on the plates under the conception that Lakhmina
belonged with the Neotremata. Schuchert noted the same resemblance when looking over
the plates of this monograph and called my attention to it. I then made a careful study of
all of the specimens and by the use of acid developed several interiors of dorsal valves. I
found that the supposed perforation of the apex of the ventral valve of Lakhmina was the
result of the breaking out of the minute apex; that the dorsal valve of Neobolus warthi was
the same as the dorsal valve of Lakhmina linguloides and that two genera and four species had
been based on specimens of Neobolus warthi.

The external characters of all of the shells referred to Neobolus and Lakhmina are the
same. Only one specimen of the interior of the ventral valve that shows anything of the
platform beneath the visceral area occurs in the collections; this was referred to Lakhmina
by Waagen, but the accompanying dorsal valves were first described as Neobolus. By com-
paring the illustrations of Waagen [1891, Pl. II] the student will notice that figure 8c of the
interior of the dorsal valve of Neobolus is essentially the same as the interior of the dorsal valve
of Lakhmina (fig. 4c) with the exception of the thickened platform.

It may seem as though it were forcing unlike forms into one species to place the specimen
represented by Plate LXXXI, figures 2f, 2g, and 2h, with those represented by figures 47A
and 47B, page 567, but with our present information it appears to be necessary to do so.

All authors have classified the shells described as Lakhmina linguloides with Trimerella,
and Hall and Clarke [1892c, p. 29] state that in the present condition of knowledge it must
be regarded as the earliest representative of the trimerelloid Brachiopoda. The external form
is similar to that of Obolus and the interior characters might readily have been developed from
that genus, but the platform is posterior and not central as in the trimerelloids.

y NEOBOLUS WARTHI Waagen.

Text figures 47A—B, page 567; Plate I, figures 3, 4, 4a-b, 5, 5a; Plate LXX XI, figures 2, 2a-h.

Neobolus warthi WAAGEN, 1885, Mem. Geol. Survey India, Paleontologia Indica, 13th ser., Salt Range Fossils, vol. 1,
pt. 4, fas. 5, pp. 758-759, Pl. LXXXIV, figs. 3-8. (Described and discussed as a new species. The three
specimens represented by figs. 4, 5a-b, and 7 are redrawn in this monograph, Pl. I, figs. 4, 4a, and 3, respec-
tively.)

Neobolus wynnei WAAGEN, 1885, idem, pp. 759-761, Pl. LXXXV, figs. 1 and 2. (Described and discussed as a new
species. The two specimens represented by figs. la-c and 2a-c are redrawn in this monograph, Pl. I, figs. 5
and 5a, respectively.)

Davidsonella linguloides WAAGEN, 1885, idem, pp. 764-766, Pl. LXX XV, figs.3-6. (Described and discussed as a new
species. The four specimens represented by figs. 3a-b, 4a-b, 6, and 5 are redrawn in this monograph, Pl.
LXXX1, figs. 2, 2d, 2e, and 2fh, respectively.)

Davidsonella squama WAAGEN, 1885, idem, pp. 766-767, Pl. LXXXVI, fig. 1. (Described and discussed as a new
species. In 1891 [Pl. II, figs. 6a-b] Waagen figures the specimen represented by figs. la-b as Neobolus warthi.
The specimen represented by figs. la—b is redrawn in this monograph, Pl. LX XXT, fig. 2a.)

Neobolus warthi Waagen, OrHLERT, 1887, Manuel de conchyliologie, by Fischer, p. 1263, fig. 1012. (No text refer-
ence. The two figures are copied from Waagen, 1885, Pl. LX XXIV, figs. 6 and 7.)

Lakhmina linguloides (Waagen), OEHLERT, 1887, idem, p. 1265, fig. 1015. (No text reference. The two figures are
copied from Waagen, 1885, Pl. LX XXYV, figs. 5 and 6.)

Lakhmina linguloides Waacen, 1891, Mem. Geol. Survey India, Paleontologia Indica, 13th ser., Salt Range Fossils,
vol. 4, pt. 2, Pl. II, figs. 3a-cand4a-c. (No text reference. Figs. 3a-b and 4a-b are copied from Waagen, 1885,
Pl. LXXXYV, figs. 3a-b and 4a-h, respectively; figs. 3c and 4c are copied from Waagen, 1885, Pl. LXX XV,
figs. 6 and 5, respectively.)

Neobolus warthti WaaGEN, 1891, idem, Pl. II, figs. 5-9. (No text reference. Figs. 5, 6a-b, 8a-b, and 8c are copied
from Waagen, 1885, Pl. LX XXIV, fig. 4; Pl. LXX XVI, figs. la-b; Pl. LXX XIV, figs. 5a-b; and Pl. LXXXIV,
fig. 7; respectively. The specimen figured by Waagen, 1885, Pl. LXXXYVI, figs. la-b, as Davidsonella squama
is figured by him later, 1891, Pl. II, figs. 6a-b, as Neobolus warthi.)

OBOLIDE. 567

Neobolus wynneti WAAGEN, 1891, Mem. Geol. Survey India, Paleontologia Indica, 13th ser., Salt Range Fossils,
vol. 4, pt. 2, Pl. Il, figs. 10 and 11. (No text reference. Figs. 10 and 11 are copied from Waagen, 1885, Pl.
LXXXYV, figs. 2 and 1, respectively.)

Lakhmina linguloides (Waagen), Hatt and CrarKe, 1892, Eleventh Ann. Rept. State Geologist New York for 1891,
p. 234, figs. 243 and 244. (No text reference. Figs. 243 and 244 are copied from Waagen, 1885, Pl. LXXXV,
figs. 5 and 6, respectively.)

Neobolus wartht Waagen, Haut and CiarKke, 1892, idem, p. 245, figs. 250 and 251. (No text reference. Figs. 250
and 251 are copied from Waagen, 1885, Pl. LX XXIV, figs. 6 and 7, respectively.)

Lakhmina linguloides (Waagen), Hatt and CrarKe, 1892, Forty-fifth Ann. Rept. New York State Museum for 1891,
p- 590, figs. 243 and 244. (No text reference. Figs. 243 and 244 are copied from Hall and Clarke, 1892a, figs.
243 and 244, p. 234.)

Neobolus wartht Waagen, Hatt and CiarxKe, 1892, idem, p. 561, figs. 250 anf 251. (No text reference. Figs. 250
and 251 are copied from Hall and Clarke, 1892a, figs. 250 and 251, p. 245.)

Lakhmina linguloides (Waagen), Haut and CrarxKe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, p. 28, figs.
13 and 14. (No text reference. Figs. 13 and 14 are copied from Waagen, 1885, Pl. LXXXYV, figs. 5 and 6,
respectively.)

Neobolus warthi Waagen, Han and CrarKs, 1892, idem, p. 84, figs. 39 and 40. (No text reference. Figs. 39 and
40 are copied from Waagen, 1885, Pl. LX XXIV, figs. 6 and 7, respectively.)

Lakhmina linguloides (Waagen), Frecu, 1897, additional plates inserted in 1897, in Lethzea geognostica, pt. 1, Lethea
palzeozoica, atlas, 1876, Pl. 14, figs. 4a-b. (Figs. 4a and 4b are copied from Waagen, 1885, Pl. LXXXV, figs.
5 and 6, respectively.) —

Neobolus warthi Waagen, FrrcuH, 1897, idem, Pl. I a, figs. 5a-b. (Figs. 5a and 5b are copied from Waagen, 1885,
Pl. LXXXIV, figs. 7 and 4, respectively.)

The generic description embraces the characters of the species. By the courtesy of Dr.
T. H. Holland, director Geological Survey of India, I have had the opportunity of studying
the type material and thus of coming to an in-
dependent opinion as to the genus and species.

Waagen [1885, p. 758] states that the sur-
face of the shell is perfectly smooth. I find
that some of the specimens are worn nearly
smooth, while others preserve concentric lines
and striz of growth. The shells show the same
variation of surface as do shells of Obolus that FIGURE 47.— Neobolus warthi Waagen. A, Interior of dorsal valve
have lived on a sandy bottom and been more or showing area, median ridge, and thickening of the shell beneath

Brio the visceral area. On the right side the main vascular sinus is
less worn by the attrition of the sand. clearly shown. This drawing is from a cast of a dorsal valve in

A

The second species of the genus, “‘ Neobolus which the platform has not been developed. B, Outline of a

Os) . platform, median ridge, and vascular sinuses in a dorsal valve,
EEE differs from the types of Neobolus obtained by removing the outer shell by acid (X 3). (See p. 565.)
warthi, according to Waagen [1885, p- 760], only The specimens represented by figures 47A and 47B were collected

in having the surface striz more distinctly pre- in the Khussak group of the Middle Cambrian at Kiura (Khewra),

. 2 Salt Range, India. The specimen represented by figure 47A is shown
served. This character does not appear to be in Plate I, fig. 4b, also, the present figure being the correct and later

of specific value, as there is considerable vari- drawing from a cast made in a natural mold. The specimen from
a © : 6 which the cast was taken is in the collection of the Geological Survey

ation in this respect among the type specimens 4; India (Cat. No. 3/780).
of Neobolus warthi.

The relations of Neobolus warthi and Lakhmina linguloides have been mentioned under
observations on the genus Neobolus (page 565).

The shell described as “‘ Davidsonella squama” by Waagen [1885, p. 766] appears to be
a dorsal valve of “ Lakhmina linguloides.” He figures it [1891, Pl. II, figs. 6a—b] as Neobolus
wartht. I found some rock attached to the cardinal margin in such a manner as to give the
effect of a low pointed apex. On clearing the rock away the apex was found to be marginal
and the cardinal border the same as in the dorsal valves of ‘‘Lakhmina linguloides.” The
shell is the largest found at Juténa. It has a length of 13 mm.; width, 14.5 mm.

The specific name was given in honor of Dr. H. Warth.

FoRMATION AND LOcALITY.—Middle Cambrian: Lower portion of the ‘‘ Neobolus beds” of the Khussak group,
in purplish-colored, fine-grained, micaceous sandstones at the following localities [Waagen, 1885, p. 759]; (357c)
near the fresh-water springs in a gorge above the salt mines at Kiura (Khewra); (357a) at Jutdna; and (sei) at Chél
Hill; all in the Salt Range, India.

568 CAMBRIAN BRACHIOPODA.

¥
Subfamily BICIIN Walcott and Schuchert.
Genus BICIA Walcott.@

Bicia Waucort, 1901, Proc. U. 8. Nat. Mus., vol. 23, pp. 676-678. (Described and discussed as below as a new genus.)
Bicia Waucort, 1908, Smithsonian Misc. Coll., vol. 53, No. 4, Pl. XI, and pp. 142 and 144. (Classification of genus.)

Shell subequivalve, moderately convex, longitudinally ovate, with the ventral valve
sometimes subacuminate and the dorsal valve subcircular. Beak of both valves as now
known terminates at the posterior margin. Surface marked by concentric and radiating
striee.

Shell substance unknown in an unaltered condition. Shell structure formed of a thin
surface layer and numerous inner layers or lamelle more or less oblique to the outer layer.
Area of the ventral valve usually on the plane of the edges of the valve, but in some instances
it rises at a low angle; it is usually high and triangular in outline, but the apex may be rounded
and the base curved forward at the median line; divided midway by a narrow pedicle furrow
and again at each side by a narrow flexure line that extends forward and outward from the
apex. Area of dorsal valve short; it appears in both of the known species to rise from the
plane of the edges of the valve. Striz of growth subparallel to the base across the areas.

The main vascular sinuses of the ventral valve are narrow and extend forward from the
projecting center of the base of the area, gradually separating as they cross the visceral area
and extend forward beyond the transverse center of the shell. In the dorsal valve they appear
to separate more rapidly and to follow the outer margin of the central cavity, except in the
second species. A narrow median septum is indicated in the dorsal valve on the crest of a
strong median ridge.

One of the striking features in both of the known species of this genus is the oblong oval
boss (b) that is present in the ventral valve of most adult shells; it is situated each side of
the forward projecting central portion of the area, with the larger axis extending forward and
outward when the shell is subacuminate, and transverse when the shell is broadly rounded;
in the dorsal valve of Bicia gemma (Billings) it is not so well defined as in B. whiteavesi Wal-
cott; the boss (b) is bounded by the margin of the base of the area, the narrow elongate sulcus
containing the marginal muscle scars and the base of the main vascular sinuses. In B. whit-
eavesi it reaches its greatest development in both valves, resembling in position and surface
characters the posterior occlusor scars of Pholidops implicata von Huene [1899b, p. 278, Pl. X].
Somewhat similar bosses occur in the ventral valve of Obolella crassa (Hall) and Obolus apollinis
Hichwald, but they are not developed to the extent they are in Bicia. They appear to occur
only in those thick shells that have deposits of shell substance over the visceral area.

The outline of the parietal scar in the ventral valve is well shown by Plate L, figure 1g;
it incloses a heart-shaped visceral area in the ventral valve closely circumscribing the muscle
scars; its general course in the dorsal valve is suggested by the position of the muscle scars.

Five pairs of muscle scars have been observed. The rather large central scars (h) in the
dorsal valve are placed close to the broad median ridge, a little back of the center; the small
anterior laterals (j) are slightly in advance of the centrals on the median ridge, close to the
median line; the transmedian scars (i) are almost under the edge of the area and near the
outer margin; the outside (1) and middle (k) laterals are slightly in advance and farther out
than the transmedian scars. The centrals, middle laterals, and outside laterals of the ventral
valve are grouped in the narrow space on each side of the U-shaped forward-projecting portion
of the visceral area (c, fig. 2); traces of individual scars have been seen, but they can not be
separated so as to identify them; the transmedian (i) and anterior lateral (j) scars are close
to the outer margin of the ventral valve and just in advance of the oblong boss in front and
each side of the forward-projecting base of the area; umbonal and pedicle scars unknown,
except what may possibly be a small umbonal scar in the dorsal valve of B. whiteavesi Walcott
[PI. L, fig. 2e, at g].

a Prior to the definition of the genus Bicia the type species was described under the following genera:

Obolella Billings [1872a, p. 218; 1872b, p. 357]. Obolella Hall and Clarke [1892c, pp. 69 and 71).
Obolella Walcott [1886b, p. 116; 1891a, p. 612].

Pei Ao 7

OBOLIDA. 569

Type.—Obolella gemma Billings. Second species: Bicia whiteavesi Walcott.

Observations.—Bicia is a form that combines many of the characteristics of Obolella and
Obolus. Jt resembles Obolella in the arrangement of the muscle scars and main vascular sinuses
of the interior of the valves. It differs in having a high area with an open pedicle groove in
the ventral valve and an elevated ridge or boss in the back portion of the dorsal valve that
in one species, B. whiteavesi, is very prominent. The ensemble of the dorsal valve of Bicia
is unlike that of either Obolella or Obolus. Bircia with its thick shell, high area, deep central
cavity (heart-shaped cavity of Mickwitz [1896, p. 71]), arrangement of visceral cavity, muscle
scars, and vascular markings in the ventral valve, is a true Obolus of the O. apollinis Eichwald
type; but in its more elongate outline, strongly striated surface, and in nearly all details of
the dorsal valve it is quite distinct.

Of the two species now referred to the genus, B. gemma (Billings) has an unusually thick
shell and a very marked deposit of shell substance over the visceral area in the ventral valve,
the posterior portion of the same area in the dorsal valve, and along its median line. In the
second species there is a considerable deposit over the same area, with the exception of the
median line, where the strong median ridge is absent.

The generic name is derived from the town of Bic, Quebec, near which the type species
was found.

Bicta Gemma (Billings).

Plate L, figures 1, la—n.

Obolella gemma Briiines, 1872, Canadian Naturalist, 2d ser., vol. 6, No. 2, pp. 218-219; fig. 5, p. 217. (Described
and discussed as a new species.)

Obolella gemma Brutines, 1872, Am. Jour. Sci., 3d ser., vol. 3, p. 357, fig. 5, p. 355. (Described and discussed. Fig. 5
is copied from fig. 5 of the preceding reference.)

Obolella gemma Billings, Watcorr, 1886, Bull. U. 8. Geol. Survey No. 30, pp. 116-117, Pl. X, figs. 2, 2a-e. (Copies
the original description, Billings, 1872a, pp. 218-219, and discusses species. The specimens represented by

Pl. X, figs. 2b, 2c, 2d, and 2e, are redrawn in this monograph, Pl. L, figs. 1i, 1j, 1k, and lc, respectively.)
Obolella gemma Billings, Watcort, 1891, Tenth Ann. Rept. U. 8. Geol. Survey, p. 612, Pl. LX XT, figs. 5, 5a-c, Pl.

LXXII, figs. 2 and 2a. (No text reference. Figs. 5, 5a-c are copied from Walcott, 1886b, Pl. X, figs. 2, 2d, 2b,

and 2c, respectively; Pl. LXXII, figs. 2 and 2a, are copied from Walcott, 1886b, Pl. X, figs. 2a and 2e, respec-

tively.
Obolella sen Billings, Hann and CuarKe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, pp. 69 and 71;
fig. 30, p. 71; and Pl. II, figs. 42-44. (Discussed under the genus Obolella. Fig. 30, p. 71, is copied from Wal-

‘cott, 1886b, Pl. X, fig. 2d; Pl. II, fig. 42, is drawn from the specimen figured by Walcott, 1886b, Pl. X, fig. 2a.)
Bicia gemma (Billings), Waucorr, 1901, Proc. U. S. Nat. Mus., vol. 23, pp. 678-680. (Described and discussed as

below.)

General form ovate, with ventral valve subacumimate when the beak is extended, or
obtusely acuminate when the beak is rounded; dorsal valve oval to subcircular in outline;
the range of variation in the outlme of the valves is shown by the figures on Plate L. The
convexity of the valves is fairly strong and nearly the same in each where they are embedded
in the same matrix.

Surface of shell marked by numerous slightly irregular concentric strie and lines of growth,
by fine radiating striz between stronger radiating lines, and on some shells by strongly developed,
elevated, radiating striz; the radiating strize are often slightly irregular and interrupted, as
shown by figure la. When the outer surface is partly worn away it is smooth, or the shell
has a peculiar surface formed by traces of the radiating, interrupted, or undulating striz (fig.
1d). The concentric striz and limes of growth are shown on the outer surface of the inner
layers of the shell and on the interior surface where rather strong radiating strie are often
beautifully shown.

The shell is unusually thick and strong for one so small; those from St. Simon and Troy
appear to be calcareous and formed of one solid layer; this is probably owing to their condi-
tion of preservation, as ina weathered specimen lamelle oblique to the outersurface are clearly
shown, and indications of lamellze on the central and posterior portions point to the same
shell structure as in Obolus and Obolella.

570 CAMBRIAN BRACHIOPODA.

The ventral valves average about 5 mm. in length, the largest beng 7 mm.; average width
4 mm., largest 5 mm. The dorsal valve is about one-fifth shorter than the ventral.

The area f the ventral valve is usually on the plane of the margins of the valve, but in
many specimens it rises at angles varying from 1° to 10°; it is high and narrow, somewhat
as In Obolus (Schmidiia) acuminatus Mickwitz (Pl. XIV, figs. 2, 2a) and divided midway by
a strong, rounded, narrow pedicle furrow; the strie of growth are rather coarse and. arch
forward at the center and across the pedicle furrow, following the contour of the base of the
area; the position of the flexure line is sometimes clearly shown by a narrow depression. The
area of the dorsal valve is short and easily escapes observation except in well-preserved shells;
it sometimes has a shght central pedicle depression and often is only a short, almost smooth
surface extending well out on the cardinal slopes of the valve.

The muscle scars as far as determined are arranged as in Obolus. The umbonal and pedicle
scars have not been observed. The elongate, oval central scars (h) are rather large in the dorsal
valve and situated on each side of the strong median ridge about the middle of the valve; in
the ventral valve they are crowded in with the scars of the middle and outside laterals; the
anterior laterals (j) are barely discernible in one specimen of the dorsal valve as small oval dots
on the central ridge a short distance mm advance of the centrals; in the ventral valve they are
close to the base of the area and near the outer edge of the shell; the middle and outside
laterals in the ventral valve are situated in the trapezoidal area (c), but do not appear to be
separable on the specimens in the collection; in the dorsal valve they are well shown in
advance of the transmedian scar @). The latter @) im the ventral valve is merged with the
anterior laterals (j). ;

Of the vascular markings the main sinuses of the ventral valve are about all that is clearl
shown, although the position of the parietal scar is indicated in advance of the center of the
shell (fig. 1g). One of the most strongly marked characters of the dorsal valve is the median
ridge (mr); it varies in strength and outline in different shells, but is usually a prominent
feature; it extends to the frontal margin in most shells, but m some it narrows and is less
prominent anteriorly. A few specimens show a slight depression crossing it just in front of
the central scars, and one has two minute anterior lateral muscle scars directly on the ridge,
the parietal scar passing across just in front of them. The thickened shell beneath the visceral
cavity of the ventral valve is present in nearly all adult shells; it varies greatly in size, form,
and thickness; in some valves it covers the entire area within the parietal scar (Pl. L, figs.
1h and 1k), and in others only a portion (Pl. L, fig. 11). The thickenmg in the dorsal valve
is along the posterior border of the central cavity; this is best shown in the cast (PI. L, fig. 11).
The median ridge is also frequently more or less enlarged.

ForMATION AND LOCALITY.—Lower Cambrian: (20) Limestone bowlders in conglomerate on shore at east entrance
to harbor at Bic, Rimouski County; (2p) limestone on south side of the road a little west of Bic, and half mile (0.8
km.) west of the road leading to the wharf, Rimouski County; and (319b) limestone bowlders in conglomerate at
St. Simon, Rimouski (?) County; all in the Province of Quebec, Canada.

(392¢ [Billings, 1872a, p. 218]) At the Straits of Belleisle, Labrador.

(32a) Limestone 0.75 mile (1.2 km.) west of Riders Mills on the Harlem Extension Railroad, about 9 miles
(14.4 km.) north-northeast of Chatham, Kinderhook quadrangle (U. 8. Geol. Survey), Columbia County; (27) even-
bedded and conglomeratic limestones on the ridge in the eastern suburb of Troy, Rensselaer County; (29a) limestone
1 mile (1.6 km.) below the New York Central Railroad depot at Schodack, Rensselaer County; and (2b) limestone
just north of Beman Park, in the northeastern part of the city of Troy, Troy quadrangle (U. 8. Geol. Survey),
Rensselaer County; all in New York.

Bicta wHITEAvest Walcott.

Plate L, figures 2, 2a-e.

Bicia whiteavesi Waucorr, 1901, Proc. U. S. Nat. Mus., vol. 23, p. 680. (Characterized and discussed as below as a
new species.)
This species is associated with Bicia gemma (Billings) im a bedded limestone at Troy,
New York. It differs from the latter, in the dorsal valve, in the absence of the median
ridge; the presence of a broad area; in the presence in the interior of both valves of two large,

OBOLID. Eel

circular, scarlike spots, one on each side of the median line and just in front of the area, that
recall in appearance and position the posterior adductor scars of Crania. The ventral valve is
so much like that of B. gemma (Billings) that it is difficult to decide whether such shells as are
represented by Plate L, figures 2a and 2b, should not be referred to B. gemma. ‘There is a
gradual transition in pom and character of the interior of the ventral valve between the
extremes represented in B. gemma by figures 1h and li, through figures 1f, 1g, 1k, 2a, and
2b, to the extreme form of B. whiteavesi, figure 2c. If it had not been for the “Hass in figure
2c, and the dorsal valve, figure 2e, associated with it, I would have hesitated to refer it to a
distinct species.

The specific name is given in honor of Prof. J. F. Whiteaves, of the Geological Survey
of Canada.

ForMATION AND LOCALITY.—Lower Cambrian: (2b) Limestone just north of Beman Park, in the northeastern
part of the city of Troy, Troy quadrangle (U. S. Geol. Survey), Rensselaer County, New York.

Genus DICELLOMUS Hall.a

Dicellomus Hawu, 1873, Twenty-third Ann. Rept. New York State Cab. Nat. Hist., p. 246. (Characterized as a new
genus.

Schmidtia Tes (in part) [not VorBortu], 1880, Handbuch der Palzontologie, Bd. 1, Abth. 1, p. 665. (Doubtfully
places Dicellomus as a synonym of Schmidtia.)

Obolella Billings, Han and Crarxke (in part), 1892, Eleventh Ann. Rept. State Geologist New York for 1891, pp.

240-241. (Dicellomus is included with Obolella as a synonym.)

Obolella Billings, Haut and CrarKe (in part), 1892, Forty-fifth Ann. Rept. New York State Museum for 1891, pp.

556-557. (Copy of preceding reference.)

Obolella Billings, Hatt and CLARKE (in part), 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, pp. 66-73, espe-
cially pp. 72-73. (Dicellomus is discussed as a synonym of Obolella.)
Dicellomus Hall, Waucort, 1899, Mon. U.S. Geol. Survey, vol. 32, pt. 2, p. 446. (Discussed, part of the paragraph

being copied below, see p. 572.)

Dicellomus Hall, Waucott, 1905, Proc. U. 8. Nat. Mus., vol. 28, pp. 312-313. eae and discussed essentially
as below.

Dicellomus a GrRaBau and Sumer, 1907, North American Index Fossils, vol. 1, p. 189. (Described.)

Dicellomus Hall, Waucort, 1908, Smithsonian Misc. Coll., vol. 53, No. 4, Pl. XI, and pp. 142 and 144. (Classification
of genus.)

Shell small; general form ovate to subsemicircular, biconvex, with apices marginal. Sur-
face of outer shell finely punctate in all species where it is preserved uninjured. Interior or
middle lamellz marked by radiating strie and minute puncte; inner surface finely punctate.
The shell is thick in all the species now known, and is built up of a thin, outer, scabrous layer,
numerous inner layers or lamellz, and a thin inner layer. Shell substance apparently calcareo-
corneous.

Nhe interior of the ventral valve (Pl. LI, figs. 1c, 1d) shows a stent area with a median
pedicle groove; an elongate visceral area; well-marked main vascular sinuses; large, composite
sears (cl) where the posterior muscles, i. e., transmedian and outside and anterior laterals, were
attached; and a short shelf that extended into the valve from each side of the pedicle groove.
This extension appears to correspond to the dental plate in the articulate brachiopods, and
it has a slight thickening at the anterolateral margin that suggests a short tooth. In material
received from Prof. W. A. Finkelnburg from Hudson, Wisconsin, I worked out several interiors of
the ventral valve and found in all of them more or less of the remains of a lining of the pedicle

aThe synonymy for this genus does not give a complete record of the various genera under which the species now included in Dicellomus were
formerly placed; it gives only those references in which the genus is discussed or described. To complete the record the following mere generic
references are listed:

Obolus Owen [1852, p. 501]. Lingulepis Meek and Hayden [1865, p. 3].
Lingula Hall [1861, p. 24]. Obolella Meek and Hayden [1865, p. 4].
Obolella Billings [1861b, p. 7; 1861c, p. 946]. Obolelia ? Hall f 867, p. 112).

Lingula Hall [1862, p. 435]. Obolus Whitfield [1875, p. 103).

Obolelia Billings [1862c, p. 421; 1862d, p.67; 1862e, p. 218}. Obolus ? Whitfield [1880, p. 338].

Obolella Meek and Hayden [1862, p. 435]. Obolella Whitfield [1880, pp. 339 and 340].
Obolella Hayden [1862, p. 73]. Obolella Walcott [1886b, p. 111].

Lingula Whitfield [1862, p. 136]. : Obolella Schuchert [1897, p. 275].

Obolella ? Hall [1863, p. 133]. Dicellomus Walcott [1901, p. 673; 1908d, p. 77].

572 CAMBRIAN BRACHIOPODA.

tube that extended on each side above the plane of the cardinal area so as to form a concave
plate similar to the posterior portion of the spondyhum in Syntrophia (Pl. CII, fig. 6f). If
the sides of the plate were extended farther and united about the pedicle, a tube would result
similar to that of Obolella (Pl. LV, figs. 1f and 1h), and ultimately to that of Botsfordia (Pl.
LVI, figs. 4e and 4g). This “llavie 3 in Dicellomus, while suggesting a spondylium, is more nat-
urally interpreted as the beginning of a pedicle tube.

The interior of the dorsal valve has a well defined but very narrow area in one species,
D. politus (Hall), that is hollowed out so as to form a shallow groove on each side, apparently
for the reception of the short tooth of the ventral valve. No good posterior margins of the
valve could be found of the other species of the genus. The composite scar is large, and in
one shell it is subdivided into three small scars that were the poimts of attachment of the trans-
median and outside and middle laterals. The central and anterior lateral scars are arranged as
in Obolus; the centrals are large and located on the sides of the visceral area; the anterior
laterals are small and are located at the anterior end of the visceral area.

Type.—Lingula polita Hall.

Observations—When referring to Dicellomus in 1899 I said [1899, p. 446]:

When proposing that the genus Dicellomus include Obolella polita, Professor Hall [1873, p. 246] stated that the
grooving or emargination of the apices of both valves and the thickening of the edges of the shell on each side below
the apex, together with the form and character of the muscular impressions, would separate the species from Obolella.
Again, Messrs. Hall and Clarke [1892c, p. 72] gave a fuller description of Dicellomus politus, but owing to the poor
character of the material they did not feel confident that it should be recognized as generically distinct from Obolella
chromatica. Material now in the collections of the United States Geological Survey clearly shows that Professor Hall’s
provisional conclusion was correct, and that Dicellomus politus is generically distinct from Obolella chromatica.

The presence of the large, composite, cardinal muscle scars in each valve suggests that
a search be made for a foraminal opening, as in Obolella, Linnarssonella, and Acrotreta. No
trace has been found externally, and the interior of the ventral valve does not show evidence
of it, except in the pedicle plate. Dicellomus appears to include characteristics of Obolus and
Obolella, and the presence of incipient dental plates, teeth, and dental grooves suggests an
articulate shell. 7

DicELLOoMUS APPALACHIA Walcott.
a Plate LIII, figures 4, 4a-g.
Dicellomus appalachia Watcort, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 314. (Described and discussed as below as
a Dew species. )

This shell has been identified with D. politus (Hall) in the preliminary studies of the genus
Dicellomus. I find that while it has the same type of shell structure and general form, it
differs in being less elongate proportionally and in the details of the form and positions of the
muscle scars and vascular markings of the interior of the valve; it differs in the latter respect
from D. nanus (Meek and Hayden). The outer thin layer has a dull, finely roughened surface
that is minutely punctate. When the outer layer is exfoliated the surface of the layer beneath
is highly polished and marked by exceedingly fine radiating and concentric striz and lines
of growth. The interior of the dorsal valve shows the large central muscle scars with the
minute anterolateral scars almost in contact with them. A composite scar (cl, Pl. LIII,
fig. 4d) shows the separate points of attachment of the transmedian (i), outside lateral (1),
and middle lateral (k) scars. The variation in the length of the visceral cavity of the dorsal
valve, as shown in Plate LIII, figures 4d to 4g, is very great, and it may be that figures 4f and
do pelone to another species.

This species occurs in great abundance in both limestones and shales. It is the Appa-
lachian representative of the widely distributed D. politus of the mterior of the continent,
hence the specific name.

FORMATION AND LOCALITY.—Middle Cambrian: (2z) Nolichucky (?) shale [Campbell, 1899, p. 3], near Shipley
Ferry, 0.75 mile (1.2 km.) northwest of Bethany Chapel, northeastern corner of the Roan Mountain quadrangle (U. 8.

Geol. Survey); (2z’) shales in the Honaker limestone [Campbell, 1899, p. 3], at Wallace switch, about 5 miles (8 km.)
northeast of Bristol, Bristol quadrangle (U. S. Geol. Survey); and (874c) sandy shale (Nolichucky?) [Campbell, 1899,

ee

OBOLIDA. D713

p- 3], 8 miles (12.8 km.) northeast of Shipleys, near the line between the Roan Mountain and Bristol quadrangles (U. 8.
Geol. Survey); all in Sullivan County, Tennessee.

(103a) Upper part of the second shale south of the ridge of sandstone in the Rome formation (‘‘Town Knobs”), on
the road from Rogersville to Dodson Ford, near the line between the Morristown and Greeneville quadrangles (U. 8S.
Geol. Survey); (102) Rogersville shale just south of road, one-half mile (0.8 km.) southwest of Rogersville, on the
road to Melinda Ferry [Keith, 1896a, areal geology sheet]; (104) shale in railroad cut 0.5 mile (0.8 km.) from Rogers-
ville on the road to Holston River, near the line between the Morristown and Greeneville quadrangles (U. S. Geol.
Survey); (124a) shale (Nolichucky?) overlying the limestone which rests on the Rogersville shale, on Big Creek,
southeast of Harlan Knob, 4 miles (6.4 km.) northeast of Rogersville [see Keith, 1905, p. 4, and areal geology sheet];
and (374b) shale 1.25 miles (2 km.) from Rogersville, near the line between the Morristown and Greeneville
quadrangles (U. S. Geol. Survey); all in Hawkins County, Tennessee.

(107) Limestone in Bull Run; and (107b) shales in railroad cut in Bull Run; both northwest of Copper Ridge
[Keith, 1896b, areal geology sheet], 11 miles (17.6 km.) northwest of Knoxville, Knox County, Tennessee.

(11a) Sandstone between First and Armstrong creeks, in the southeast corner of the Maynardville quadrangle
(U. 8. Geol. Survey), Union County; (117c) shale at Buckingham Ford on Hollis Creek, 5 miles (8 km.) south-
east of Greeneville, Greene County; (874a) limestones 2 miles (3.2 km.) south of Coal Creek, Anderson County;
and (119) limestone in various localities in Jefferson and Hawkins counties; all in Tennessee.

(16) Conasauga limestone, Blountsvilte Valley, Blount County; (89) limestone in Murphrees Valley, Blount
County; (90a) shales at Cedar Bluff, Cherokee County; (90b) Conasauga limestone, in cut on Louisville and Nash-
ville Railroad, near Woodstock, Bibb County; (144c) limestone near the top of the beds exposed near N. K. Burns’s
barns, near Swansea (Viola), Blount County; and (91) Conasauga (‘‘ Coosa”) shale, at Cedar Bluff, Cherokee County;
all in Alabama.

(47h) Shales on Wolf Creek, 6 miles (9.6 km.) below Rocky Gap, Bland County, Virginia.

DiceLLomus nanus (Meek and Hayden).

Plate LIII, figures 1, la-I, 2, 2a, 3, 3a-d.

Obolella nana Merx and Haypen, 1862, Proc. Acad. Nat. Sci. Philadelphia for 1861, vol. 13, pp. 4835-436. (Described
and discussed as a new species.)

Obolella nana Meek and Hayden, Hayprn, 1862, Am. Jour. Sci., 2d ser., vol. 33, p. 73, figs. la-b and 2a-b. (Char-
acterized and discussed. The two specimens represented by figs. 2a and 2b are redrawn in this monograph,
Pl. LILI, figs. 2a and 2, respectively.)

Obolella nana Meek and Hayden, Bruines, 1862, Geol. Survey Canada, Paleozoic Fossils, vol. 1, pp. 67-68. (Original
reference, Meek and Hayden, 1862, pp. 435-436, copied.) é

Obolella nana Murx and Haypen, 1865, Smithsonian Contrib. Knowl., No. 172, Paleontology Upper Missouri, pt. 1,
p. 4, Pl. I, figs. 3a-d. (Described and discussed. Figs. 3a—b and 3c-d are copied from Hayden, 1862, p. 73,
figs. 2a and 2b, respectively.)

Obolella nana Meek and Hayden, Wurrriuxp, 1880, U. 8. Geog. and Geol. Survey Rocky Mtn. Region, Rept. Geology
and Resources Black Hills of Dakota, by Newton and Jenney, pp. 340-341, Pl. II, figs. 14-17. (Copies the
description given by Meek and Hayden, 1865, p. 4, and discusses species. Fig. 17 is copied from Meek and
Hayden, 1865, Pl. I, fig. 3d.)

Obolella nana Meek and Hayden, Watcort, 1886, Bull. U. S. Geol. Survey No. 30, p. 111. (Discussed.)

Obolella nana Meek and Hayden, Han and CLiarke, 1892, Nat. Hist. New York, Paleontolos gy, vol. 8, pt. 1, pp. 69-70.
(Discussed)

Dicellomus nanus (Meek and Hayden), Waucorr (in part), 1899, Mon. U.S. Geol. Survey, vol. 32, pt. 2, p. 447, Pl.
LX, figs. 3a-d (not fig.3). (Synonymy and new localities given. Figs. 3b and 3d are drawn from the specimens
figured by Hayden, 1862, p. 73, figs. 2a and 2b, and are redrawn in this monograph, Pl. LIII, figs. 2a and 2,
respectively. The specimens represented by figs. 3a and 3c are not figured in this monograph. The specimen
represented by fig. 3 is referred in this monograph to Lingulella desiderata.)

Dicellomus nanus (Meek and Hayden), Waxcorr, 1905, Proc. U. 8. Nat. Mus., vol. 28, pp. 314-315. (Described and
discussed essentially as below.)

The principal characters of this species are the same as Dicellomus politus (Hall). The
two forms differ exteriorly in D. nanus being more convex on the umbones and less elongate.
The interior of the ventral valve shows a less elongate visceral area, a relatively larger com-
posite muscle scar (cl); the interior of the dorsal valve of D. nanus has a much larger com-
posite muscle scar and a broader visceral area with the central muscle scar farther from the
median line.

One of the types of D. nanus is the interior of a ventral valve (Pl. LIII, fig. 2), on which
there is a subtriangular depression (c) that appears to have been the path of advance of the
areas, on each side of the median space, in which the central muscle, and the middle and outside

574 CAMBRIAN BRACHIOPODA.

lateral muscles, were attached. Another shell from the Bighorn Mountains shows something
of the same character (Pl. LIII, fig. 11).

The area of the ventral valve is short, and divided midway by a shallow pedicle furrow;
area of dorsal valve unknown.

The exterior of the shell appears to be smooth and slightly polished, except for fine con-
centric striz and lines of growth and what appear to be scattered puncte.

The average size of the adult shells is from 3 to 4 mm., the length and width usually being
nearly the same.

The exact horizon of the type specimen is unknown. It occurs in a somewhat friable,
purplish sandstone, unlike any beds in the Middle Cambrian Deadwood formation that I met
with. The specimens from the limestones of the Bighorn Mountains, etc., appeat to belong

to the Upper Cambrian.

ForMATION AND LOCALITY.—Ordovician: (302v) Sandstones 2 miles (3.2 km.) west of the main summit of Buffalo
Fork Peak [St. John, 1877, pp. 468 and 469 and map opposite p. 324 (ear station XLIX)], about 25 miles (40 km.)
east of Jackson Lake, Uinta County, Wyoming.

Upper Cambrian: (1522) West side of Dry Creek below Pass Creek; and (158a) limestone north of Hast Gallatin
River near Hillsdale; both in the Threeforks quadrangle (U. 8. Geol. Survey), Gallatin County, Montana.

(302u) Upper limestone of the Deadwood formation, north of Cheever’s ranch, on the summit of the Bighorn
Mountains, Wyoming.

Middle Cambrian: (170) Sandstone about 10 miles (16.1 km.) south-southeast of Bald Mountain, Bighorn Moun-
tains; (302m) middle of shale above lower sandstone on Billy Creek in the Bighorn Mountains; (302y) sandstone on
Johnson Creek, Bighorn Mountains; and (302b) limestones near Crowfoot Ridge, Gallatin quadrangle (U. 8S. Geol.
Survey), Yellowstone National Park; all in Wyoming.

(302z) Limestone on Mill Creek, near Landusky, Little Rocky Mountains, Chouteau County, Montana.

(355) Sandstones on Red Canyon Creek, southwest side of Black Hills; and (355d) sandstone im the Black Hills;
both in South Dakota. “

(11j) Basal part of Bonneterre limestone, Mine Lamotte, Madison County; and (11m) drill cores of limestone at
horizons 10 and 20 feet (3 and 6 m.) above the Lamotte sandstone, St. Francois County; both in Missouri.

DiceLtLtomus parvus Walcott.

Plate LX X XIX, figures 11, 1la-d.

Dicellomus parvus Watcort, 1905, Proc. U. S. Nat. Mus., vol. 28, pp. 315-316. (Described and discussed as below as a
new species.)

General form ovate, with the ventral valve subacuminate and dorsal valve broad oval
to subcircular. Valves moderately convex. Surface of outer shell dark and polished; it is
marked, when not abraded, by fine, clearly defined, concentric stri# and occasional lines of
erowth. The largest ventral valve has a length of 2.5 mm. and a width of 2mm. The shell
is strong but not thick. Shell substance apparently calcareocorneous.

Ventral valve uniformly convex, except that the slopes toward the cardinal margins are
more abrupt than elsewhere; apex appears to be marginal. The interior of the valve shows a
short, low, median ridge in the center of the visceral cavity; on each side, and a little in front of
the end of the median ridge are the trapezoidal areas for the attachment of muscle scars; rather
small, composite cardinal muscle scars occur close to the cardinal margins.

Dorsal valve somewhat less convex than the ventral; apex marginal. The interior of the
valve shows well-defined composite cardinal muscle scars, a narrow median septum, and a faintly
impressed main vascular sinus that curves outward and forward at about one-third the distance
from the outer margin to the median septum; the central muscle scars are small and situated
back of the center of the valve on each side of a low median swelling on which the median
septum occurs; the position of the anterior lateral muscle scars is indicated at the end of the
median septum a little in advance of the center of the valve.

Observations.—This minute shell has the generic characters of Dicellomus politus (Hall), but
it differs specifically in its minute size and the positions of the muscle scars'in the dorsal valve.

FORMATION AND LOCALITY.—Middle Cambrian: (C6) Thin slabby limestone in the wpper shale member of the Kiulung
group [Blackwelder, 1907a, pp. 37 and 41 (2d list of fossils), and fig. 10 (bed 12), p. 38], 2.5 miles (4 km.) southwest of

OBOLID”®. ND

Yenchuang, Sintai district, Shantung; and (C32) a fine-grained bluish-black limestone bowlder believed to have come
from the lower part of the Kisinling limestone [Blackwelder, 1907b, p. 272], collected in river drift 1 mile (1.6 km.)
south of Chonpinghien, on Nankiang River, southern Shensi; both in China.

DiIcELLOMUS PECTENOIDES (Whitfield).
Text figures 48A—B; Plate LII, figures 6, 6a-c.

Obolus pectenoides WHITFIELD, 1875, Rept. Reconnaissance Black Hills of Dakota, by Ludlow, p. 103, unnumbered
plate, figs. 1-3. (Described and discussed as a new species.)

Obolus ? pectenoides WuitrreLD, 1880, U.S. Geog. and Geol. Survey Rocky Mtn. Region, Rept. Geology and Resources
Black Hills of Dakota, by Newton and Jenney, pp. 338-339, Pl. II, figs. 18and 19. (Described. The specimens
represented by figs. 18 and 19 are redrawn in this monograph, Pl. LII, figs. 6 and 6a, respectively.)

Obolella pectenoides (Whitfield), ScuucuERT, 1897, Bull. U. 8. Geol. Survey No. 87, p. 275. (Merely changes generic
reference. ) ;

Dicellomus pectenoides (Whitfield), Waxcorr, 1901, Proc. U. S. Nat. Mus., vol. 23, p. 673. (Merely changes generic
reference.) é

Dicellomus pectenoides (Whitfield), Watcorr, 1905, idem, vol. 28, p. 316. (Characterized.)

This is the largest shell of the several species of the genus. A ventral valve 9 mm. long has
a width of 11 mm. All that is known of the structure of the shell indicates that it was like D.
politus (Hall) (Pl. LIL) and D. nanus (Meek and Hayden) (PI. LITT). This species differs from
all other described species by the anterior posi-
tion of the central muscle scars of the dorsal
valve, its larger size, and the thickening beneath
the visceral cavity of the ventral valve. Area of
ventral valve short and much like that of D. nanus
(Pl. LI, fig. 1c). Specimens from Eau Claire,
Wisconsin, show a thickening of the shell beneath

A

the visceral CRY of the veg al valve not unlike Figure 48.—Dicellomus pectenoides (Whitfield). A, Cast of in-
that of Elkania desiderata (Billings) Gir Till, fie. la). terior of ventral valve from Locality 78a, “‘St. Croix sand-
s s S * CRS nein 1 stone’’ at Bau Claire, Wisconsin (U.S. Nat. Mus. Cat. No.
The interior of the dorsal valve ae) quite dissimilar 51909). B, Cast of interior of dorsal valve from Locality 100,
in the two species. “St. Croix sandstone’? at Menomonie, Dunn County, Wis-
consin (U. 8. Nat. Mus. Cat. No. 51910). v, Visceral cavity;

FORMATION AND LOCALITY.—Upper Cambrian: (15la) Lime- vs, main vascular sinuses; h, central muscle sears.

stone In point overlooking Churn Canyon, on the west side of
the Bridger Range; and (158) limestone north of East Gallatin River near Hillsdale, Threeforks quadrangle (U.S.
Geol. Survey); both in Gallatin County, Montana.

(78a) “St. Croix sandstone” in the topmost quarry on Mount Washington, near Eau Claire, Eau Claire County;
and (100) ‘“‘St. Croix sandstone” near Menomonie, Dunn County; both in Wisconsin.

Middle Cambrian: (355b) Sandstone in the Deadwood formation on Castle Creek, on the west side of the Black
Hills; and (164) sandstone in the Deadwood formation in the cliffs on the east side of the valley near Deadwood, Black
Hills; both in South Dakota.

(355¢ [ Whitfield, 1875, p. 103]) Sandstone on French Creek, Black Hills, South Dakota.

Ss DickLLOMUs PoLiTus (Hall).

Text figures 16A—B, page 314; 49A—B, page 576;¢ Plate LII, figures 1, la~k, 2, 2a-i, 3, 4, 4a, 5, 5a-b.

Obolus appolinus? OwEN (not ErcHwaxp), 1852, Rept. Geol. Survey Wisconsin, Iowa, and Minnesota, Appendix,
p. 501, Pl. 1 B, figs. 9, 11, 15, and 20. (Occurrence mentioned.)

Lingula polita Haru, 1861, Rept. Supt. Geol. Survey Wisconsin, p. 24. (Described and discussed.)

Obolella sp. 3 Brnurnes, 1861, Geol. Survey Canada, Paleozoic Fossils, vol. 1, p. 7. (Characterized.)

Obolella sp. 3 Brtrnes, 1861, Report on the Geology of Vermont, vol. 2, p. 946. (Copy of preceding reference.)

Lingula? polita Hau, 1862, Rept. Geol. Survey Wisconsin, vol. 1, p. 435, fig. 1, p.21. (Generic reference discussed.)

Obolella polita (Hall), Bixuines, 1862, Am. Jour. Sci., 2d ser., vol. 33, p. 421. (Note on the dates of publication of the
references cited above, Hall, 1861, p. 24, and Billings, 1861, p. 7.)

Obolella sp. 3 Brxtrnes, 1862, Report on the Economic Geology of Vermont, by Hager, p. 218. (Copy of Billings,
1861b, p. 7.)

Lingula polita Hall, Warrrrexp, 1862, Am. Jour. Sci., 2d ser., vol. 34, p. 136. (Note on the date of the first reference to
Lingula polita.)

Obolella? polita Hau, 1863, Sixteenth Ann. Rept. New York State Cab. Nat. Hist., pp. 133-134, PI. VI, figs. 17-21.
(Described and discussed.)

aText figures 16A-B and 49A-B are the same.

57 6 CAMBRIAN BRACHIOPODA.

Lingulepis prima Merx and HaypeEn, 1865, Smithsonian Contrib. Knowl., No. 172, Paleontology Upper Missouri, pt. 1,
p. 3, Pl. I, figs. 2a-b. (Described and discussed as a new species. The specimen represented by figs. 2a and
2b is redrawn in this monograph, Pl. LII, fig. 2h.)

Obolella ? polita Hatx, 1867, Trans. Albany Inst., vol. 5, pp. 112-1138, Pl. I, figs. 17-21. (Text and figures copied from
Hall, 1863, pp. 133-134, Pl. VI, figs. 17-21.)

Dicellomus polita Hau, 1873, Twenty-third Ann. Rept. New York State Cab. Nat. Hist., p. 246. (Changes generic
reference.)

Obolella polita (Hall), WurtrreLp, 1880, U.S. Geog. and Geol. Survey Rocky Mtn. Region, Rept. Geology and Resources
Black Hills of Dakota, by Newton and Jenney, pp. 339-340, Pl. II, figs. 12 and 13. (Described and discussed.
The specimen represented by fig. 13 is redrawn in this monograph, Pl. LII, fig. 2g; fig. 12 is not.)

Obolella polita (Hall), Waxcotr, 1886, Bull. U. S. Geol. Survey No. 30, p. 111. (Discussed.)

Obolella polita (Hall), Harn and CLarxe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, pp. 72 and 73, Pl. II,
figs. 37-41. (Discussed as a species of Dicellomus, but the use of that term is held in abeyance until the species
shall have been proven generically distinct from Obolella. Figs. 40 and 41 are copied from Hall, 1863, Pl. VI,
figs. 20 and 21.) ;

Dicellomus politus (Hall), Watcorr, 1899, Mon. U.S. Geol. Survey, vol. 32, pt. 2, pp. 443 and 446, Pl. LX, figs. 4and 4a.
(Discussed, establishing the generic distinctness of Dicellomus. The specimens represented by figs. 4 and 4a
are redrawn in this monograph, Pl. LII, figs. 1j and 1c, respectively.)

Dicellomus politus (Hall), Waxcorr, 1905, Proc. U.S. Nat. Mus., vol. 28, p.313. (Copy of text referred to in preceding
reference.)

Dicellomus politus (Hall), Waxcort, 1905, idem, pp. 316-318. (Described and discussed as below, although some
changes and additions have been made.)

Dicellomus politus (Hall), Grasau and Sumer, 1907, North
American Index Fossils, vol. 1, pp. 189-190, fig. 224,
p- 190. (Described. The three figures in fie. 224 are
copied from Hall, 1863, Pl. VI, figs. 17, 20, and 21.)

General form ovate, with the ventral valve
subacuminate; biconvex, the ventral valve usually
more convex than the dorsal. Surface smooth as
the specimens usually occur, but a few examples
show that there is a thin outer layer covered with

FIGURE 49.—Dicellomus politus (Hall). A, Interior of ventral fjne papillee and puncte that appear to be placed
valve (fsp, pseudospondylium or pedicle plate; i, transmedian

scars; j, anterolateral scars; v, visceral cavity; vs, main yas- on very fine, more or less inosculating ridges. .

cular sinuses). B, Posterior portion of the interior of a Concentric lines of crowth of varying strength

ventral valve, showing a strongly developed area (fsp, pseudo- 5

spondylium or pedicle plate; a, inside section of area; f, show on the outer surface, also on the various

lesan Mats, 2), GUNISGO SEAMS BIRD). inner layers or lamelle. When the outer layer is
rocTuervemens eoseentel by Hewes 4 2 wetom exfoliated or wom off by attrition of the sand, the
son, Wisconsin (U. S. Nat. Mus. Cat. Nos. 51917a and 51917b, surface of the inner layer is marked by radiating
respectively). The same figures are reproduced on page 314. striz and concentric lines of growth that are a
marked feature of the species. The radiating striz may be uniform in size, or with 4 to 6 very
fine strie between two stronger elevated striz. Inner surface smooth to the eye, but a strong
lens shows that it is finely punctate, with exceedingly fine, irregular, raised Imes all over the
surface. The intermediate layer is more coarsely and irregularly punctate.

The shell is thick, and is built up of a thin, scabrous, outer layer, a middle layer made up
of several highly polished lamelle, and a thin mner layer. The numerous inner lamelle are
oblique to the outer surface over much of the shell, and thus give it thickness. Shell sub-
stance caleareocorneous. The usual length of the ventral valves from Wisconsin is about
6 mm., width 5 mm., with the same width and length for the dorsal valve. Specimens from
the Black Hills average a trifle larger than those from Wisconsin. ;

Ventral valve with a uniform convexity over the central portions, from which the surface
slopes gently to the margins. Apex nearly if not quite marginal. Casts of the interior indi-
cate a short cardinal area that extends out on the cardinal margins of the shell and appears
to merge into the margins. On each side of the pedicle furrow a thin plate or shelf (sh) extended
into the valve on the plane of the margins of the shell. Some of the casts indicate that these

OBOLID. a17

plates had a projecting boss or tooth that articulated in a rude manner with the depressions
on the posterior, flattened, inner margin of the dorsal valve. If this interpretation is correct
the teeth and plates correspond to the teeth and dental plates of the articulate brachiopods
and the plates may mark the beginning of a spondylium.

A number of interiors from Hudson, Wisconsin, show a concave plate in the pedicle furrow,
the edges of which rise above the plane of the cardinal area; this plate is evidently the begin-
ning in Dicellomus of the pedicle tube, as shown in Obolella (Pl. LV, figs. le, 1f, and 1h). In
some shells the plate appears to extend into the shell beyond the anterior margin of the car-
dinal area and it then has the appearance of a small spondylium. I think, however, that it is
only the secretion of shelly matter about the pedicle and not connected with the development
of a spondylium; the latter is indicated by the extension of the toothlike processes already
referred to.

The posterior lateral, transmedian, and anterior lateral muscles were undoubtedly
attached within the area of the composite scar (cl) (PI. LII). The visceral area and pos-
terior portions of the main vascular sinuses are well outlined, but no muscle scars or details of
the vascular system have been preserved in the material studied.

Dorsal valve most convex back of the center. Apex marginal. The interior of the valve
shows shallow depressions in the flattened posterior margin (a) that suggest dental cavities
for the reception of the dental projections of the ventral valve. The central muscle scars
(h) are shown a little back of the center of the valve, where a low median ridge bifurcates
(Pl. LI, fig. 11). In some shells a sharp median septum is shown, also narrow main vascular
sinuses.

Observations.—The reference to this species of the specimens from the siliceous shale at
Helena is rather doubtful, as the shells are compressed and distorted. (See Pl. LII, figs. 4
and 4a.) :

Shells agreeing with D. politus in all points available for comparison occur in the basal,
probably Middle Cambrian, sandstone beneath the great limestone series of Arizona. The
material is abundant and preserved very much in the same condition as that from the Deadwood
formation of the Black Hills of South Dakota.

In sandstones in the basal part of the Upper Cambrian Reagan sandstone in Oklahoma
a few shells were found that appear to be identical with D. politus. They have the elongate
form of that species, which is unknown in any other species of the genus.

In the collections made by the Fortieth Parallel Survey there are specimens so closely
resembling D. politus that they are identified as such, although the dorsal valve is rather
transverse.

Dicellomus politus differs from D. nanws (Meek and Hayden) and D. pectenoides (Whit-
field) in being more elongate, also in the details of the interior markings of the valves. From
D. appalachia Walcott it differs i interior markings, and, as specimens average, in being
more elongate.

FORMATION AND LOCALITY.—Upper Cambrian: (82b) ‘‘St. Croix sandstone” along the railroad track near Taylors
Falls, Chisago County; (97 and S97x) “‘St. Croix sandstone” at Reads Landing, foot of Lake Pepin, Wabasha County;
(339i) [Owen, 1852, desc. of Pl. IB) sandstones of F1b of Owen’s section, below Mountain Island, in Mississippi River, nearly
opposite the old mouth of Black River; and (98a) “St. Croix sandstone” at Marine Mills, on St. Croix River, Washington
County; all in Minnesota.

(78a) “St. Croix sandstone” in the topmost quarry on Mount Washington, near Eau Olaire, Hau Claire County;
and (98 and 98x) “St. Croix sandstone” near Eau Claire, Eau Claire County; (79s) ‘‘St. Croix sandstone” in bluff
near Hudson, St. Croix County; (328c) “St. Croix sandstone” at Alma, Buffalo County; (88) ‘St. Croix sandstoné”
near Trempealeau, Trempealeau County; (100a) ‘“‘St. Croix sandstone” at Ettrick, Trempealeau County; (80) “St.
Croix sandstone” 0.66 mile (1.1 km.) southwest of the railway depot, Menomonie, Dunn County; and (100) “‘St.
Croix sandstone” near Menomonie, Dunn County; all in Wisconsin.

(128a) Shales on the Louisville and Nashville Railroad, 1.5 miles (2.4 km.) southeast of Cog Hill, near the line
between Polk and McMinn counties, Tennessee.

62667°—vou 51, pr 1—12—37

578 CAMBRIAN BRACHIOPODA.

(9x) Sandstones lying between beds of quartzite underlying the 300 feet of limestone at the top of the Reagan ;
sandstone, SW. + sec. 17, T. 4 N., R. 12 W., about 11 miles (17.7 km.) northwest of Fort Sill, Comanche County,
Oklahoma.

Upper? Cambrian: (358a) Siliceous limestone on Ash Creek, in Pinal County, Arizona.

Middle Cambrian: (84 and 84f) ‘‘St. Croix sandstone” at Dresbach, opposite the mouth of Black River, Winona
County; (339e) ‘‘St. Croix sandstone” on Mountain Island, in Mississippi River, just above the mouth of Trem-
pealeau River; and (84s) “St. Croix sandstone” near Dakota, Winona County; all in Minnesota.

(79x) ‘‘St. Croix sandstone” near the flour mill on Beaver Creek, north of Galesville; and (828g) ‘‘St. Croix sand-
stone,’’ Wisconsin shore of Mississippi River, near Trempealeau; both in Trempealeau County, Wisconsin.

(167) Sandstone beneath limestone and resting on pre-Cambrian “‘slates, schists, and pegmatites” in bluff 9
miles (14.4 km.) west of Custer, Black Hills; (855e) sandstone in the central part of the Black Hills; and (855) sand-
stones in Red Canyon 4 Creek , southwest side of the Black Hills; all in South Dakota.

(11m) Drill cores of limestone in the Bonneterre limestone at horizons 10 and 20 feet (8 and 6 m.) above the
Lamotte sandstone, at Flat River, St. Francois County, Missouri.

(829b) Thin-bedded limestone collected by the Wheeler Survey in Utah.

(5k) Limestone in Meagher County, on the road to Wolsey, about 1 mile (1.6 km.) south of the divide at the
head of Sawmill Creek, and 8 miles (12.8 km.) south of Neihart, Little Belt Mountains quadrangle (U. 8. Geol. Sur-
vey), Cascade County; (302k) limestone near Gallatin, Threeforks quadrangle (U.S. Geol. Survey), Gallatin County;
(302s) © dark siliceous shale in a quarry in Last Chance Gulch, south slope of Mount Helena, 1.5 miles (2.4 km.)
south of Helena, Lewis and Clark County; and (340f) lowest beds exposed at the mouth of Bear Creek, Little Belt
Mountains; all in Montana.

DIcELLOMUs PROLIFICUS Walcott.
Plate LX X XIX, figures 10, 10a-b.

Dicellomus prolificus Watcorr, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, p. 77, Pl. VIII, figs. 3 and 3a. (Char-

acterized and discussed as below asa new species. Figs. 3 and 3a are copied in this monograph, Pl. LXX XIX,

‘ figs. 10 and 10b, respectively.)

This species differs from Dicellomus politus (Hall), to which it appears to be most nearly
related, by the greater convexity of the ventral valve, its higher umbo, and, in most shells,
a greater narrowing toward the apex. The dorsal valve differs from that of D. politus in
being more rounded on the cardinal margins. It is also to be noted that no traces of muscle
scars or vascular markings have been observed on many interiors and casts of the interior
of the valves, while in D. politus they are prominent on most casts and often on the interior
of the valves. The range of outline of the valves of D. politus might include those of D. pro-
lificus, but the convexity of the ventral valve and the smooth interior seem to distinguish the
latter species.

Great numbers of the separated valves occur im several thin layers of gray limestones near
the summit of the cliffs on the south side of Marjum Pass.

ForRMATION AND LOCALITY.—Middle Cambrian: (10z) About 2,900 feet (884 m.) above the Lower Cambrian
and 1,500 feet (457.2 m.) below the Upper Cambrian in the central part of the limestone forming la of the Marjum

limestone [Walcott, 1908f, p. 179], in the long cliff about 2 miles (3.2 km.) southeast of Marjum Pass [ Walcott, 19088,
Pls. XIII and XV], House Range, Millard County, Utah.

DIcELLoMUs sp. undt. Walcott.
Plate LII, figures 7, 7a.

Dicellomus sp. undt. Watcort, 1905, Proc. U.S. Nat. Mus., vol. 28, p. 319. (Mentioned as below as a possible new
species.)
A single specimen of a ventral valve very much like that of Dicellomus appalachia (Wal-
cott) occurs with material from the Paradoxides forchhammer zone at Andrarum. A series of
specimens would probably prove that it is the representative of an undescribed species.

ForMATION AND LOCALITY.—Middle Cambrian: (3101) Paradoxides forchhammeri zone at Andrarum, 20 miles
(32.2 km.) northwest of Simrishamn, Province of Christianstad, Sweden.

a Some of the specimens arelabeled asfrom Redwater Canyon and some as from Red Canyon Creek, the former locality being given by Whitfield
[1882, p. 340).
b The specimens from this locality are somewhat doubtfully referred to this species. (See Pl. LII, figs. 4 and 4a.)

KUTORGINID.. 579

Superfamily KUTORGINACEA Walcott and Schuchert.
Family KUTORGINIDA® Walcott and Schuchert.
Genus KUTORGINA Billings.

Kutorgina Brurines, 1861, Geol. Survey Canada, Paleozoic Fossils, vol. 1, p. 9, footnote. (Characterized and dis-
cussed as a possible new genus; see below for copy.)

Kutorgina Brines, 1861, Report on the Geology of Vermont, vol. 2, p. 948, footnote. (Copied from preceding refer-
ence.)

Kutorgina Br1nes, 1862, Report on the Economic Geology of Vermont, by Hager, p. 220, footnote. (Copied from
preceding reference.)

Kutorgina Billings, Davipson, 1868, Geol. Mag., vol. 5, p. 312. (Merely questions genus.)

Obolella (Kutorgina) (Billings), Dau, 1870, Am. Jour. Conchology, 2d ser., vol. 6, pt. 2, pp. 154 and 163. (Described.)

Kutorgina Billings, Davipson, 1871, British Fossil Brachiopoda, vol. 3, pt. 7, No. 4, p. 342. (Copy of Davidson,
1868, p. 312.)

Kutorgina Billings, Dax, 1877, Bull. U. 8. Nat. Mus., No. 8, pp. 40-41. (Discussed.) j

Kutorgina Billings, Zrrre, 1880, Handbuch der Palzontologie, Bd. 1, Abth. 1, p. 664. (Described in German.)

Kutorgina Billings, Waucorr (in part), 1886, Bull. U. 8S. Geol. Survey No. 30, pp. 101-102. (Original characteri-
zation, Billings, 1861b, p. 7, copied, and genus described and discussed. The generic description is based
on specimens now referred to Micromitra, Micromitra (Paterina), Micromitra (Iphidella), and Billingsella, as well
as upon those representing Kwtorgina.)

? Kutorgina Billings, OEHLERT, 1887, Manuel de conchyliologie, by Fischer, p. 1262. (Described in French, with
figures of ‘‘ Kutorgina cingulata Linnarsson.’’)

Kutorgina Billings, BencuEr, 1891, Am. Jour. Sci., 3d ser., vol. 41, footnote, pp. 345-346. (Generic relations dis-
cussed.)

Kutorgina Billings, Harz and CiarKe, 1892, Eleventh Ann. Rept. State Geologist New York for 1891, pp. 247-248.
(Described and discussed.)

Kutorgina Billings, Haun and CrarKe, 1892, Forty-fifth Ann. Rept. New York State Museum for 1891, pp. 563-564.
(Copy of preceding reference.)

Kutorgina Billings, Hat and CLARKE (in part), 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, pp. 90-94.
(Copies Walcott, 1886b, pp. 101-102, on pp. 91-92, and describes and discusses genus, including species now
referred to Micromatra, Micromitra (Iphidella), Micromitra (Paterina), Protorthis, and Billingsella, as well as
those referred to Kutorgina.)

Kutorgina Billings, Hari and CLarxke, 1892, idem, p. 183. (Discusses generic relations; see the seventh reference in
the synonymy of Botsfordia pulchra, p. 607.)

Kutorgina Billings, Waxcort, 1905, Proc. U.S. Nat. Mus., vol. 28, pp. 306-308. (Original characterization, Billings,
1861b, p. 7, copied and genus described and discussed essentially as below.)

Kutorgina Billings, GRaBAU and Summer, 1907, North American Index Fossils, vol. 1, p. 209. (Described.)

Kutorgina Billings, Watcorr, 1908, Smithsonian Misc. Coll., vol. 53, No. 4, Pl. XI, and pp. 142 and 145. (Classifi-
cation of genus.)

Billings [1861b, p. 9] proposed the genus Kutorgina in a footnote accompanying the
description of the type species K. cingulata. He says:

Since the above was written I have examined many casts of the interior of this species, and am inclined to the
opinion that it is generically distinct from Obolella chromatica. From the very considerable elevation of the beak
the dorsal valve must have an area and probably a foramen. In one specimen there are two large oval impressions
faintly impressed, but still distinctly visible. There is no trace of the lateral scars, and the form, notwithstanding

the characters of the surface, conveys the idea of an Orthisina. Should, upon further examination, my suspicions
turn out to be well founded, I shall call the genus Kutorgina, after the celebrated European naturalist, Kutorga.

From present information of the genus the following diagnosis is prepared:

Shells inequivalve, transverse or elongated. Ventral valve convex, with apex marginal or
incurved over the pseudo-area; cardinal area rudimentary, without any delthyrium or well-defined
pseudodeltidium; the latter usually extends one-half the distance from the apex to the plane
of the posterior margin of the valve; interior of ventral valve with well-defined main vas-
cular sinuses, with a visceral area between the sinuses. Dorsal valve flat or slightly convex,
rising to a small, elevated umbo; apex marginal and usually pointing upward; cardinal area

aThe synonymy for this genus does not give a complete record of the various genera under which the species now included in Kutorgina were
formerly placed; it gives only those references in which the genus is discussed or described. To complete the record the following mere generic
references are listed:

Lingula Bornemann [1891, p. 439]. Kutorgina von Toll [1899, p. 26].
Kutorgina Bornemann [1891, p. 440]. Kutorgina Matthew [1899a, p. 189; 1899d, p. 98].
Orthis ? Tate [1892, p. 185]. Kutorgina Walcott [1901, p. 695].

Kutorgina Frech [1897, Pl. I A, figs. 6a-b].

580 CAMBRIAN BRACHIOPODA.

short, rudimentary, and without well-defined pseudodeltidium. Interior of ventral valve with
median septum between the central and posterolateral muscle scars.

Observations.—The short cardinal areas of the valves leave a broad open space between
them for the passage of the pedicle. The areas are more than reflected posterior margins of
the valves, as they have transverse lines of growth and a suggestion of a pseudodeltidium.
These features are more rudimentary than in Micromitra. Kutorgina includes the larger cal-
careous shells, and Micromitra the somewhat more specialized, smaller, corneous shells. The
exterior form of the valves of Kutorgina suggest Msusia festinata (Billings), with which the
type species, K. cingulata (Billings), is associated in Vermont and at Bic Harbor.

The genus was named in honor of Kutorga.

KuToRGINA CINGULATA (Billings).

Text figures 3, page 299; 8, page 299; 50A—C, page 581; Plate V, figures 1, la-s.

Obolella (Kutorgina) cingulata Brutines (in part), 1861, Geol. Survey Canada, Paleozoic Fossils, vol. 1, pp. 8-9, figs. 8
and 10 (not fig. 9). (Described as a new species. Fig. 9 is that of a specimen now referred to Rustella edsons.)
Obolella (Kutorgina) cingulata Bruuines (in part), 1861, Report on the Geology of Vermont, vol. 2, p. 948, figs. 347 and
349 (not fig. 348). (Text and figures copied from Billings, 1861b, p. 9, figs. 8and 10, p. 8. Fig. 348 is that of a
specimen now referred to Rustella edsont.)

Obolella (Kutorgina) cingulata Bruuines (in part), 1862, Report on the Economic Geology of Vermont, by Hager, p. 220,
figs. 347 and 349 (not fig. 348). (Text and figures copied from preceding reference. Fig. 348 is that of a speci-
men now referred to Rustella edsont.)

Obolella cingulata Butines, 1863, Geol. Survey Canada, Fifteenth Rept. Progress, p. 284, figs. 287a and 287b (not fig.

Ki 287c). (No text reference. Figs. 287a and 287b are copied from Billings, 1861b, figs. 8 and 10, p. 8. Fig.
287c represents a specimen now referred to Rustella edsont.)

Kutorgina cingulata (Billings), Waucorr (in part), 1886, Bull. U. S. Geol. Survey No. 30, pp. 102-104, Pl. IX, figs. 1,
la-f (not figs. lg and 1h). (Original description, Billings, 1861b, p. 9, copied and species described and dis-
cussed. The specimens represented by figs. 1, la-f are redrawn in this monograph, PI. V, figs. 1c, 1b, 1d, 1a, 1,
li, and 1h, respectively. Specimens referred to Rustella edsoni are mentioned on p. 103 and are figured, Pl. IX,
figs. 1g and 1h.)

Kutorgina cingulata (Billings), Brrcuer, 1891, Am. Jour. Sci., 3d ser., vol. 41, footnote, pp. 345-346. (Discusses
generic relations. )

Kutorgina cingulata (Billings), Watcort, 1891, Tenth Ann. Rept. U. 8. Geol. Survey, p. 609, Pl. LXIX, figs. 1, la-f
(not figs. 1g and Ih). (Mentioned. Figs. 1, la-t are copied from Walcott, 1886b, Pl. IX, figs. 1, laf. Figs.
1g and 1h represent specimens now referred to Rustella edsont.)

Kutorgina cingulata (Billings), Hatt and CrarxKe, 1892, Eleventh Ann. Rept. State Geologist New York for 1891,
Pl. IV, figs. 11-18. (No text reference.)

Kutorgina cingulata (Billings), Harn and CrarxKe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, p. 92, figs.
47-49: Pl. IV, figs. 10-17. (Mentioned in discussing genus. Figs. 47-49 are copied from Walcott, 1886b,
Pl. IX, figs. 1b, la, and li, respectively. Figs. 13, 14, and 17 are copied from figs. 11-13 of the preceding
reference.)

Kutorgina cingulata (Billings), Frecu, 1897, Additional plates inserted in 1897 in Lethzea geognostica, pt. 1, Lethea
paleeozoica, atlas, 1876, Pl. I 4, figs. 6a-b. (No text reference. Figs. Ga—b are copied from Walcott, 1886b,
Pl. IX, figs. la and 1, respectively.)

Kutorgina cingulata (Billings), von Tout, 1899, Mém. Acad. imp. sci. St.-Pétersbourg, 8th ser., vol. 8, No. 10, pp.
26-27, Pl. I, fig. 28. (Described and discussed in German.) ;

Kutorgina cingulata Billings, Waucorr, 1905, Proc. U. 8. Nat. Mus., vol. 28, pp. 308-309. (Described and discussed
essentially as below, with the exception of the notes and figures on the shell structure.)

Kutorgina cingulata von Toll, Waxcorr, 1905, idem, p. 309. (Species and locality mentioned.)

Kutorgina cingulata (Billings), GraBau and Suimer, 1907, North American Index Fossils, vol. 1, p. 209, fig. 246.
(Described. The three figures of fig. 246 are copied from Walcott, 1886b, Pl. 1X, figs. 1, 1a, and 1b.)

General form transversely or longitudinally oval; biconvex, with the ventral much more
convex than the dorsal valve. Surface marked by concentric lines and ridges of growth and
the edges by imbricating lamellz of growth. Shell substance calcareous and fibrous. The shell
is formed of a thin, dark, compact outer layer and a thick, laminated, calcareous inner layer. It
is possible that the thin outer layer is chitinous, but it does not appear to be so.

The L’ Anse au Loup and Bic Harbor shells average about 15 mm. long by 17 mm. in width.
At the locality near Swanton, Vermont, ventral valves occur 24 mm. in length and 30 mm. in
width, and one large dorsal valve is 20 mm. in length with a width of 30 mm.

ot cee peat,

KUTORGINIDA. 581

Ventral valve in young shells moderately convex, becoming more and more convex with
increase in size and age; in young shells the slope from the front margin to the apex is nearly
straight, and the apex terminates at the posterior edge of the valve above the more or less ele-
vated pseudo-area; in old shells the curvature from the front to the apex is nearly a semicircle,
and the apex terminates in a pointed beak overhanging the pseudo-area; a mesial sinus, of vary-
ing strength, occurs on many shells, and in others it is entirely absent; the area is concave on
the outer parts; toward the center it becomes slightly flattened or convex and thus forms a
very rudimentary pseudodeltidium; it extends beneath the apex at an angle of about 45° to
the plane of the margins of the valve; the pseudo-area extends about one-half the distance from
the apex to the plane of the valve and arches gently from the lateral extremities to the center.

A partly exfoliated shell shows four dark lines radiating forward from the umbo and
two near the sides that may have something to do with the muscle scars or vascular sinuses.

FIGURE 50.—K utorgina cingulata (Billings). A, Enlargement of a portion of a transverse section of an old shell which shows its laminations and
the peculiar manner of growth (30). B, C, Vertical sections of an old shell, showing the imbricated manner of growth of the outer thin
dark layer (X30). This outer layer is not preserved in the specimen represented by A.

The specimens from which these sections were made came from Locality 25a, near Swanton, Vermont (U.S. Nat. Mus. Cat. Nos. 15337f,
15337¢, and 15337h, respectively).

I thought so in 1886 [1886b, p. 103] but am not sufficiently confident of it now to state it as a
settled conclusion. Fine punctz occur on the inner layer of the shell; also numerous radiating
lines about one-half millimeter apart.

Dorsal valve gently convex in young shells; with increase in size the umbo becomes more
elevated and the apex points upward or terminates at the union of the pseudo-area and the
upward slope of the shell on the umbo; in some shells there is a tendency for the valve to
become slightly concave in the space between the margins and the elevated umbo; the area
of the valve is narrow and with little character; on some shells it slopes beneath the apex,
and on others it slopes backward forming a low angle with the surface of the valve; the interior
of the dorsal valve shows a median septum with two central scars (h) and the anterolateral
scars (j) (Pl. V, fig. th); numerous-small vascular canals radiate from the central concave
area toward the flattened anterior and lateral half of the valve; a cast of the interior (Pl. V,

582 CAMBRIAN BRACHIOPODA.

fig. 1d) shows two vascular canals radiating forward from near the apex. Radiating lines
occur on the interior of the same character as those of the ventral valve.

Observations.—Since writing on this species in 1886 I have collected specimens showing
the character of the areas of the valves and also obtaimed further information relative to the
interior of the dorsal valve. The rudimentary areas are less advanced in development than
those of Micromitra, and the muscle scars of the dorsal valve are much like those of Obolella
and Obolus.

The presence of rudimentary teeth in Kutorgina cingulata is very difficult to demonstrate
by actual observation, owing to the character of the matrix in which the specimens occur.
That articulating processes are present, however, is indicated by the fact that in a relatively
small collection thirty of the valves are united, and the fact that the dorsal valve is rarely
in any other position than that in which it would be if teethin the ventral valve held it in its
normal position. In only a few of the specimens have the valves slid or turned either way,
as they frequently do in the inarticulates.

The specimens from Bic Harbor and east of Swanton, Vermont, are better than those
from the type locality at L’ Anse au Loup, so I have selected material from these localities for
illustration, with the exception of a dorsal and ventral valve. Many of the Vermont shells
are larger and more fully developed, but specimens of the same size as those from L’ Anse au
Loup and Bic Harbor are identical in the characters available for comparison.

FoRMATION AND LOCALITY.—Lower Cambrian: (392a) Limestones at L’ Anse au Loup, on the north shore of the Straits
of Belleisle; and (3921) arenaceous limestone at Point Amour, Straits of Belleisle; both in Labrador.
(20) Limestone bowlders in conglomerate, on shore at east entrance to harbor at Bic, Rimouski County, Quebec,

Canada.

(25a)® Limestone on the Hall (Donaldson’s) farm, 2 miles (3.2 km.) east of Swanton; and (819m) shales of No. 6
of the section at Parker’s quarry [Walcott, 1891b, p. 278], near Georgia; both in Franklin County, Vermont.

(1v) Shales of No. 3 of the Silver Peak Group, Barrel Spring section [ Walcott, 1908f, p. 189], 3 miles (4.8 km.)
north of Valcalda Spring and 4 miles (6.4 km.) west-northwest of the Drinkwater mine, Silver Peak quadrangle (U.S.
Geol. Survey), Esmeralda County, Nevada.

(35f) About 300 feet (91 m.) below the Middle Cambrian in the limestone forming 6 of the Mount Whyte forma-
tion [Walcott, 1908c, p. 242 (11)] just above the tunnel on the north shoulder of Mount Stephen, about 3 miles (4.8
km.) east of Field, British Columbia, Canada.

(347 [von Toll, 1899, p. 27]) Near Tschurskaja Station, on Lena River, Siberia.

KUTORGINA GRANULATA Matthew.

Plate V, figures 5, 5a-c.

Kutorgina granulata MartuEw, 1899, Bull. Nat. Hist. Soc. New Brunswick, vol. 4, pt. 3, No. 18, p. 189, Pl. I, figs.
2a-d. (Characterized and discussed as a new species. The specimens represented by figs. 2a, 2b, and 2c are
redrawn in this monograph, Pl. V, figs. 5 and 5a, 5c, and 5b, respectively.)

Kutorgina granulata MattHEw, 1899, Trans. Roy. Soc. Canada for 1899, 2d ser., vol. 5, sec. 4, No. 4, p. 98, Pl. V, figs.
2a-d. (Described and discussed. Figs. 2a-d are copied from figs. 2a—d of the preceding reference.)

The description by Matthew [1899e, p. 98] follows:

Shell substance calcareous. Hinge-line straight, somewhat shorter than the full width of the shell; lateral margin
straight near the hinge; front margin broadly rounded.

Ventral valve convex, the umbo considerably elevated, the posterior third of the shell somewhat more tumid
than the rest; lateral angles somewhat flattened. The area appears to have a deltidium, about one-fifth as wide as the
length of the hinge-line; this line, when viewed from behind, appears to be bent up in the middle. Interior: On
the posterior half there are a number of low vascular ridges; two of these inclose a median groove, which extends
to within a third of the front of the valve; there are about three other ridges on each side. These ridges are most
distinct near the umbo, and about three or four are found in the space of 1 millimeter.

The dorsal valve is flatter, and has the umbo depressed to the cardinal line, and the sides of the valve toward
the hinge much flattened. Interior: There is a median septum extending about one-third of the length of the valve,
and faintly indicated for another third to a point where there is a small pit on the inner surface of the valve; and
there are also radiating lines as in the ventral valve, but more numerous.

. The surface is minutely granulated. On the somewhat tumid posterior third of the valve concentric strive are
faintly visible, but they become distinct on the anterior part, and there are very fine radial lines, giving to the summit

a These specimens are in tbe collections of the Geological Survey of Canada. b The species also occurs in Locality 319e.

ne ee

ee

——— Ne

aye

te ee ee en eee

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KUTORGINID. 583

of the intervening ridgelets a beaded appearance; at certain intervals stronger concentric striz of growth show on the
surface of the shell; there are about five or six of these on its surface.

Length, 4mm.; width, 6 mm.; depth of the ventral valve, 1.0 mm.

This species is suneill than K. cingulata and differs in its ornamentation.

Observations —This little shell occurs in reddish limestone beneath a shaly band in which
I found fragments of Olenellus. Except for size it is much like Kutorgina cingulata (Billings)
in its general aspect. It differs in the details of surface ornamentation and interior radiating
lines.

The form owes its specific name to its granulated surface.

ForRMATION AND LOCALITY.—Lower Cambrian: (314b [Matthew, 1899e, p. 97]) Limestone of the ‘‘Htcheminian
series,’’ at Smith Sound, Trinity Bay, Newfoundland.

KuToRGINA PECULIARIS (Tate).

L : Plate V, figure 2.

Orthis (2) peculiaris Tatn, 1892, Trans. Roy. Soc. South Australia for 1892, vol. 15, pt. 2, pp. 185-186, Pl. II, fig. 5
(Described as a new species; see below for copy. The specimen represented by fig. 5 is redrawn in this mono-
graph, Pl. V, fig. 2.)

The original description by Tate follows:

Transversely subquadrilateral, equilateral; hinge-line in the longest anteroposterior [transverse] diameter,
straight.

Ventral (?) valve flatly convex, with an abruptly depressed and deeply bilobed ventral margin; the mesial
furrow decreases in depth as it ascends to near the umbo; the lateral margins are obliquely arched, nearly straight,

forming an angle of about 70° with the hinge-line.
Surface marked by depressed unequal folds of growth.

The author [1892, p. 185] referred to the valve as ventral (?). Its reference to Kutorgina
identifies the valve as the dorsal. I do not know of a closely related form.

The form owes its specific name to the fact that it seemed to be an unusual representative
of the genus to which it was first assigned.

ForRMATION AND LOCALITY.—Middle? Cambrian: (315a) Limestone at Parara, near Ardrossan; and (815) lime-
stone at Curramulka; both [Tate, 1892, p. 185] in Yorke Peninsula, South Australia.

KUTORGINA PERUGATA Walcott.

Ve
Plate V, figures 3, 3a-e.

Kutorgina perugata Watcort, 1905, Proc. U. 8. Nat. Mus., vol. 28, p. 310. (Described and discussed essentially as
below as a new species. )

General form ovate, biconvex. Surface marked by concentric lines of growth and more
or less strong concentric corrugations. The outer surface is ornamented by a fine network
of oblique depressed lines that leave minute rhomboidal elevations between them that look
like fine papille under a moderately strong magnifier, and the cast of the surface has much
the same appearance in a transverse light. Shell substance calcareous.

A large ventral valve has a length of 14 mm., width 16 mm. A dorsal valve 11 mm.
in length has a width of 14 mm.

The ventral valve is strongly convex in adult shells, with the highest point near the umbo
or at the apex; the apex terminates at or overhangs a rudimentary pseudo-area that slopes
beneath the shell at an angle of 45° to 60° to the plane of the margins of the valve; the pseudo-
area is concave and about half the length of the space between the apex and the plane of the
valve. Casts of the interior show well defined main vascular sinuses, with the outline of the
visceral area between them.

The dorsal valve is transverse, nearly flat in some examples and slightly convex in others.
The surface slopes gradually from the margins to near the umbo, where the slope increases
and extends to the upward-pointing apex; a rudimentary pseudo-area slopes backward from
the apex. In some examples the pseudo-area appears to be little more than a bending over

584 CAMBRIAN BRACHIOPODA.

of the posterior margins of the shell; in others it has the outline of a shghtly convex pseudo-
deltidium.

Observations.—This species in its reticulate surface ornamentation recalls Micromitra
(Iphidella) pannula (White) and Mickwitzia monilifera (Linnarsson). In form the young
shells are not unlike Kutorgina cingulata (Billings). A large, imperfect, ventral valve, 24 by
24 mm., of this genus, was collected by J. E. Clayton from the Cambrian limestone of the
Silver Peak district. It may belong to K. perugata, and it is so referred for the present. From
the shales of the Olenellus zone in Silver Canyon, White Mountain Range, a series of com-
pressed specimens was collected. Some of these show a concave pseudo-area on the ventral
valve, also strong main vascular sinuses. Some of the shells from the shales of Locality 175
have lost all traces of surface characters, only a faint, smooth impression remaining.

ForMATION AND LOCALITY.—Lower Cambrian: (313i) Limestone collected at long. 117° 20’ W., lat. 38° N., in
the western part of Esmeralda County, Nevada.

(lv) Shales of No. 3 of the Silver Peak growp, Barrel Spring section | Walcott, 1908f, p. 189], 3 miles (4.8 km.)
north of Valcalda Spring and 4 miles (6.4 km.) west-northwest of the Drinkwater mine; (175) ¢ shales carrying Olenellus
on the divide between Clayton and Fish Lake valleys, about 15 miles (24.2 km.) south-southwest of the town of
Silver Peak; and (184) shales at the summit of the Silver Peak Range, 10 miles (16.1 km.) southwest of the town of
Silver Peak; all in the Silver Peak quadrangle (U. S. Geol. Survey), Esmeralda County, Nevada.

(7) Shaly beds about 1,000 feet (305 m.) above the quartzitic beds, Silver Canyon, White Mountain Range,
Inyo County, California. ‘

KUTORGINA SARDINIAENSIS Walcott.
V Plate V, figures 4, 4a-c.

Kutorgina cingulata BoRNEMANN [not (Bruines)], 1891, Nova Acta Acad. Cxes. Leop.-Carol. Germanicée Nature Curio-
sorum, Bd. 56, No. 3, p. 440, Pl. XIX (XXXIV), figs. 22 and 23. (Described and discussed in German; see below
for translation. Figs. 22 and 23 are copied in this monograph, PI. V, figs. 4b and 4c, respectively.)

Lingula rouaulti BoRNEMANN [not Saurur], 1891, idem, p. 439, Pl. XIX (XXXIV), fig. 21. (Characterized and dis-
cussed in German. Fig. 21 is copied in this monograph, Pl. V, fig. 4.)

Kutorgina sardiniaensis Waxcorr, 1901, Proc. U. 8. Nat. Mus., vol. 23, p. 695. (Merely changes specific reference of
Bornemann’s Kutorgina cingulata.)

Kutorgina sardiniaensis Waucort, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 311. (Original description, Bornemann,
1891, p. 440, translated as below and species discussed as below as a new species.)

The original description by Bornemann follows:

Transversely oval, more or less arched, with a straight margin which is a little shorter than the greatest breadth
of the shell. Surface shows strong concentric lines of growth.

Found quite commonly in the slates with Olenopsis and Metadowides near Canal Grande, and rarely in sandstone
with Archxocyathus on Punta Pintau. The specimens in the argillaceous shale are always pressed very flat, and are
imperfect; in the sandstone, impressions of the outer surface are often found.

Here belongs, perhaps, also the shell designated above as Lingula rowaulti (?).

All that is known of the species is represented by the illustrations. It appears to be con-
generic with Kutorgina cingulata (Billings), but not specifically identical with it.
FORMATION AND LOCALITY.—Middle? Cambrian: (354) Yellowish-brown slates not far from the buildings of Canal

Grande; (354b) yellowish sandstone with Archeocyathus at Punta Pintau and elsewhere; and (354e) slate at Porto
Canal Grande; all [Bornemann, 1891, pp. 439 and 440] in the island of Sardinia, Italy.

Kuroreina sp. undt. Walcott.

Kutorgina sp. undt. Watcort, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 311. (Characterized and discussed as below

as an undetermined species.)

Ventral valve transverse, moderately convex; length, 6 mm.; width, 8 mm.; pseudo-area
short and sloping beneath the apex at an angle of about 45°.

A single cast from a coarse sandstone is all that is known of this species. It may be a young
shell of K. cingulata (Billings), but the means of comparison do not justify such a reference.

FoRMATION AND LOCALITY.—Lower Cambrian: (47a) Sandstone on the southwest side of Sallings Mountain, 2
miles (3.2 km.) east of Natural Bridge, Rockbridge County, Virginia.

a The species is somewhat doubtfully identified from this locality.
b Specimens from this locality are in the collections of the United States National Museum.

SCHUCHERTINID A. 585

Family SCHUCHERTINID® Walcott.
Genus SCHUCHERTINA Walcott.

Schuchertina Waxtcort, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 323. (Mentioned as below as a new genus.)
Schuchertina Waucort, 1908, Smithsonian Misc. Coll., vol. 53, No. 4, Pl. XI, and pp. 142 and 145. (Classification of
genus. )
The description of the type species includes that of the genus, as but one species is known.
Type.—Schuchertina cambria Walcott.
The generic name is given in recognition of the thorough work that Prof. Charles Schuchert
has done on the Brachiopoda.

\ SCHUCHERTINA CAMBRIA Walcott.
Plate LI, figures 6, 6a—m.

Schucnertina cambria Waxcotr, 1905, Proc. U. §. Nat. Mus., vol. 28, pp. 323-324. (Described and discussed as below
as a new species. )

Shell subovate, with valves obtusely acuminate, biconvex. Surface marked by concentric
lines and striz of growth and fine radiating striz. The inner and outer surface of the shells
have very fine puncte, but no traces of puncte penetrating through the shell have been
observed.

The largest ventral valveshas a length of 22 mm.; width, 23 mm.; dorsal valve, length,
17 mm.; width, 18 mm. Shell substance calcareous, rather thick on the umbonal region and
thin toward the margins.

Ventral valve subacuminate, moderately convex; on some of the larger shells a broad mesial
fold and arching of the frontal margins are present; apex terminates at the margin above a
triangular opening or delthyrium; area small and within the plane of the margins of the valve;
it is attached to the bottom of the valve and divided midway by a very slight pedicle groove; the
margins of the delthyrium-like opening sustain an angle of about 45° to the plane of the valve,
and the solid area within is at its center nearly on the plane of the valve; the anterior margins
of the area extend upward to meet the margins of the shell, thus forming a solid arched area.
The interior of the valve is marked by radiating, shallow, narrow furrows that vary in number
and strength im different shells; just in front of the area on each side of the median line oval
depressions occur, which correspond in position and shape to the diductor muscle scars of the
ventral valve of the Billingsellidz, and they are so interpreted on the figures; traces of the adduc-
tor scars are found on each side of the median line. Dorsal valve obtusely acuminate, about as
convex as the ventral valve; apex marginal on the broad, low, median arch of the posterior
margin; the only trace of an area that has been observed is shown on figure 6]; a broad,
shallow mesial smus and projecting front margin occur on adult shells; the position of the
anterior and posterior adductor muscle scars is indicated, also the umbonal thickening in
which the diductor muscles were probably attached, as there is no trace of a cardinal process;
radiating furrows like those in the ventral valve are strongly marked in adult shells.

Observations.—Schuchertina cambria is a shell that, as far as I know, is unique. In its
exterior form it suggests a biconvex orthoid genus, and this likeness is further increased by the
flabelliform scars of the ventral valve; the smooth surface and solid cardinal areas suggest
Elkamia. It may be that Schuchertina is a type derived from some early Cambrian form allied
to the Billingsellide. Its general aspects appear to affiliate it with the Orthide.

FoRMATION AND LOCALITY.—Middle Cambrian: (5k) Limestone in Meagher County on the road to Wolsey, about

1 mile (1.6 km.) south of the divide at the head of Sawmill Creek, and 8 miles (12.8 km.) south of Neihart, Little Belt
Mountains quadrangle (U.S. Geol. Survey), Cascade County, Montana.

586 CAMBRIAN BRACHIOPODA.

Order NEOTREMATA Beecher.

[péoc, young; and zpjua, perforation.]

Superfamily SIPHONOTRETACEA Walcott and Schuchert.
Family OBOLELLID4 Walcott and Schuchert.

Genus OBOLELLA Billings. 4
[Obolus.]

Obolella Brutrnes, 1861, Geol. Survey Canada, Paleozoic Fossils, vol. 1, p. 7. (Described and discussed as a new
genus. )

Obolella Bruinas, 1861, Report on the Geology of Vermont, vol. 2, p. 946. (Copy of preceding reference.)

Obolella Brxuines, 1862, Report on the Economic Geology of Vermont, by Hager, p. 218. (Copy of preceding refer-
ence.)

Obolella Brutines, 1862, Am. Jour. Sci., 2d ser., vol. 33, pp. 420-421. (Note on date of first publication.)

Obolella Billings, Haxn, 1863, Sixteenth Ann. Rept. New York State Cab. Nat. Hist., p. 131. (Original description,
Billings, 1861b, p. 7, copied.)

Obolella Billings, Meek and Haypen, 1865, Smithsonian Contrib. Knowl., No. 172, Paleontology Upper Missouri,
pt. 1, pp. 3-4. (Original description, Billings, 1861b, p. 7, copied.)

Obolella Billings, Davison, 1866, British Fossil Brachiopoda, vol. 3, pt. 7, No. 1, p. 60. (Original description,
Billings, 1861b, p. 7, copied and genus discussed.)

Obolella Billings, Hatx, 1867, Trans. Albany Inst., vol. 5, p. 108. (Original description, Billings, 1861b, p. 7, copied.)

Obolella Billings, Davipson, 1868, Geol. Mag., vol. 5, pp. 308-309. (Original description, Billings, 1861b, p. 7, copied
and genus discussed. )

Obolella Billings, Darn, 1870, Am. Jour. Conchology, 2d ser., vol. 6, pt. 2, pp. 154 and 163. (Described.)

Obolella Billings, Davison, 1871, British Fossil Brachiopoda, vol. 3, pt. 7, No. 4, pp. 338-339. (Copied from David-
son, 1868, pp. 308-309.)

Obolella Brutines, 1872, Canadian Naturalist, 2d ser., vol. 6, No. 2, pp. 217-218. (Described and discussed.)

Obolella Burnes, 1872, Am. Jour. Sci., 3d ser., vol. 3, pp. 355-357. (Described and discussed.)

Obolella Buuines, 1876, idem, vol. 11, pp. 176-178. (General description and discussion of genus and species referred
to it.)

Obolella Billings, Zrrrmu, 1880, Handbuch der Palzeontologie, Bd. I, Abth. 1, p. 664. (Described in German.)

Obolella Billings, Forp, 1881, Am. Jour. Sci., 3d ser., vol. 21, pp. 131-134. (General discussion of genus and species
referred to it.)

Obolella Billings?, Waucorr, 1884, Mon. U. S. Geol. Survey, vol. 8, pp. 67-68. (Genus discussed in description of
“ Obolella ambigua.’’) i

Obolella Billings, Waucorr, 1886, Bull. U. S. Geol. Survey No. 30, pp. 109-112. (Original description, Billings,
1861b, p. 7, and later description, Billings, 1876, p. 176, copied and species referred to the genus discussed. )

Obolella Billings, OEHLERT, 1887, Manuel de conchyliologie, by Fischer, p. 1262. (Described in French, with figures
of ‘‘O. desquamata Hall.’’)

Obolella Billings, Haru and Crarxs (in part), 1892, Eleventh Ann. Rept. State Geologist New York for 1891, pp. 240-
241. (Described and discussed, the genus Dicellomus being included as a synonym.)

Obolella Billings, Harn and Crarxe, 1892, Forty-fiith Ann. Rept. New York State Museum for 1891, pp. 956-507.
(Copy of preceding reference.)

Obolella Billings, Harn and Ciarxke (in part), 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, pp. 66-73.
(Genus described, with a general discussion of the genus and the species referred to it. The genus Dicellomus
is included as a synonym, and the reference also includes species now referred to Bicia, Obolus, etc.)

Obolella Billings, Harn and CrarKe, 1892, idem, pp. 164-165. (Generic relations discussed. )

Obolella Billings, MarrHew, 1892, Trans. Roy. Soc. Canada for 1891, vol. 9, sec. 4, No. 5, pp. 39-40. (Original
description, Billings, 1861b, p. 7, copied and literature on the genus discussed.)

a Many of the references to Obolella in the synonymy are based upon or include species now referred to other genera. The present reference
of all species formerly placed under Obolella will be found on pages 69-72. The synonymy for this genus does not give a complete record of the
various genera under which the species now included in Obolella were formerly placed; it gives only those references in which the genus is
discussed or described. To complete the record the following mere generic references are listed:

Orbicula ? Hall (1847, p. 290]. Protorhyncha ? Schuchert (1897, p. 334].
Avicula ? Hall [1847, p. 292]. Obolelia Matthew [1899d, p. 70].

Obolella ? (Orbicula ?) Ford [1871, p. 33]. Obolella Walcott [1899, p. 446].
Dicellomus Hall (1873, p. 246]. Obolella Burr [1900, p. 47].

Obolella Ford [1878, p. 128]. Obolella Grabau [1900, p. 620).

Obolella Walcott [1885a, pp. 115-117; 1885b, p. 21]. Obolella Walcott [1901, p. 674].

Obolella Ford [1886a, p. 466]. Obolella ? Matley [1902, pp. 137 and 139].
Obolella Shaler and Foerste (1888, p. 27]. Obolella Delgado [1904, p. 364].

Obolella Walcott [1890b, p. 36]. Obolelia Etheridge [1905, pp. 248 and 249].
Camerella Walcott [1890b, p. 36]. Obolella Gorham [1905, Pl. I].

Obolella Walcott [1891a, p. 611). Obolella Walcott [1905a, pp. 297 and 313].
Camarella Walcott [1891a, p. 614]. Obolelia Clark and Mathews [1906, p. 252].

Camarella Hall and Clarke [1894, p. 221].

:
:
f
4

OBOLELLID. 587

Obolella Billings, Micxwrrz, 1896, Mém. Acad. imp. sci. St.-Pétersbourg, 8th ser., vol. 4, No. 2, pp. 116, 121, and

123-126. (Copies the description of the genus as given by Hall and Clarke, 1892c, pp. 66-67, on pp. 123 and

124 and gives a general discussion of the generic relations of Obolella and Obolus, etc.)

Obolella Billings, GraBau and Sumer, 1907, North American Index Fossils, vol. 1, p. 188. (Described.)
Obolella Billings, Watcott, 1908, Smithsonian Misc. Coll., vol. 53, No. 4, Pl. XI, and pp. 142 and 145. (Classifica-
tion of genus.)

Generic characters.—Shell subequivalve, moderately convex; dorsal valve more elevated at
the umbo than the ventral; longitudinally ovate or oval in outline, with the dorsal valve some-
times transversely oval. Surface marked by concentric striz of growth and radiating striz,
except in the subgenus Glyptias, which has irregular transverse lines crossing the concentric
striz.

Shell substance unknown in an una.tered condition; it is now calcareous but it may have
been calcareocorneous as in Obolus. Shell structure formed of a thin outer layer with many
thin inner layers or lamellz more or less oblique to the outer layer; the short lamelle of the
anterior portion of the valves are more oblique than the longer lamellz of the central and
posterior portions and lie at the edges in the same plane as the margins of the valves.

Area of the ventral valve rises from the plane of the margins of the valve at angles vary-
ing from 10° to 70°; broadly subtriangular when the beak is projecting, otherwise rounded at
the posterior margin almost as much as the area of the dorsal valve; the latter is usually on
the plane of the margins of the valve and broadly rounded posteriorly; both areas are striated
parallel to the base; in the ventral valve a narrow, shallow furrow divides the area midway;
the area of the dorsal valve is divided by a narrow, raised, triangular space, bordered on
either side by a more or less deeply impressed groove formed by a narrow fold of the area
lamell; outside of this groove, and between it and the outer flexure fold of the area (f), a
depressed triangular space occurs that has led authors to consider it as the scar of the point
of attachment of cardinal muscles (Pl. LIV, figs. 1h, 11). It sometimes occurs that the inner
angle of the area of the ventral valve adjoming the pedicle opening projects forward so as to
form a toothlike knob that in the cast is shown by a deep indentation beside the cast of the
pedicle opening and between the latter and the projecting cast of the undercut beneath the
area (Pl. LV, figs. 1f, lg). Pedicle openimg or foramen of the ventral valve cylindroconical,
broad at the base and tapering to a minute apex; position of the external opening a little in
advance of the point of the beak; as indicated by casts of the tube in O. atlantica and a speci-
men of O. crassa. The opening varies in proportional size in different species; it is usually
marked by rather strong striz of growth. It extends upward and backward through the shell,
very much as does the foramen in Trematobolus and Botsfordia.

Splanchnoccele 7 of the ventral valve confined to the posterior half of the valve while in
the dorsal valve it extends forward to and in some instances beyond the center; in both valves
it extends back to the central part of the area which is bounded by the flexure lines (Pl. LIV,
figs. 11, 2g, 2m). Traces of a median septum are shown in the dorsal valve (PI. LIV, figs. 1h,
li, and Pl. LV, fig. 11), but no definite septum has been observed in the ventral valve. A
central median ridge of varying degrees of size and length often extends toward the central
portion of the dorsal valve; when it is large, a deep rounded groove usually occurs on each
side of it on the inner slope of which the central muscle scars may be situated (Pl. LIV, figs.
2k-m). Often the median ridge is practically absent (Pl. LV, figs. 11, 4a).

The grooves of the main vascular sinuses begin in each valve at the front margin of the
area near the median line, and in the ventral valve gradually extend forward and outward
toward the front half of the shell where they begin gently to curve inward, terminating toward
the front of the valve, the distance and curvature varying in different species (Pl. LIV, figs.
1f, 22, 2h, and Pl. LY, figs. 1f, 1h, 3c); in the dorsal valve the main vascular sinuses curve
out more rapidly (Pl. LIV, figs. 11, 2m) and are much less prominent; none of the secondary
radial canals or the peripheral vascular smuses have been observed. The course of the
parietal scar between the main vascular sinuses is in front of the splanchnocele in the ventral

@ Using nomenclature of Mieckwitz, 1896.

588 -CAMBRIAN BRACHIOPODA.

valves (Pl. LIV, figs. le, 22, 2h), also in the same valves it passes closely around the muscle
scars situated between the main sinuses and reaches the base of the area in line with the
flexure line of the area; in the dorsal valve it closely follows the outside limits of the muscle
scars, but it has not been traced across the main vascular sinuses.

The size and position of the pedicle and umbonal muscle scars is unknown, but they are
probably similar to those of Obolus. The central scars (h) (Pl. LIV, figs. 1h, 2k, 21) are placed
a little distance each side of the median line in the dorsal valve; in the ventral valve they are
not separable from the middle and outside laterals, which occur on each side of the front of
the visceral area at (ce) (Pl. LIV, fig. 2h). The middle and outside Jaterals of the dorsal valve
(1) are blended and lie obliquely outward before the transmedian scars (i). The transmedian
scars are close to the base of the area in both valves, and lie in the line of the prolongation of
the flexure line of the area. In number and relative position the muscle scars of Obolella as
far as known are essentially the same as in Obolus.

Observations.—The genus Obolella has been under discussion by authors for over fifty
years. In the original description Billings [1861b, p. 7] noted its resemblance to Obolus but
claimed that it was distmet on account of the difference in “‘the arrangement of the muscular
impressions.” Later [1872c, p. 356] he compared it again with Obolus, but having poor illus-
trations of both Obolus and Obolella he failed to discover the true position and relations of the
muscle scars in either. It was not until after Mickwitz’s memoir [1896] on Obolus appeared,
and the collections of Obolella made under my direction during the summer of 1899 were studied,
that any correct comparisons could be made. It then became evident that as far as known
there was practically no difference in the arrangement of the muscle scars of the two genera,
but that there were most essential differences in the cardinal area of the ventral valve. Before
working out the fact that the ventral valve was perforated by a pedicle tube or foramen, I was
at a loss to find generic difference of value, although I believed that the area of the dorsal
valve of Obolella indicated differences not readily explained.

_ The pedicle passage of Obolus varies greatly in size and form, but it is always an open
furrow. In Obolella, it is in the ventral valve a cylindroconical tube, the cardinal area rising
from the plane of the margin of the valve beneath the pedicle tube; in the dorsal valve a
slightly raised area occupies the place of the broad furrow in Obolus.

Obolella is confined to the Olénellus or Lower Cambrian fauna. Obolus, as now limited,
appears in the Lower Cambrian, and has its greatest development in the Middle and Upper
Cambrian fauna.

Bicia gemma is associated with Obolella crassa both at Bic and Troy, and the species was
teferred to Obolella by Billmgs [1872a, p. 218]. It differs so radically from Obolella in the
character of the areas of the valves and the interior markings that it is scarcely necessary to
institute comparisons between them. Lvingulella schucherti is found associated with Obolella
crassa at Troy, New York.

The interior markings of Obolella and Botsfordia are quite similar (Pls. LiV and LV, and
Pls. LVII and LIX). The same is true of Trematobolus (Pl. LX XXIII), but the pedicle open-
ing of Botsfordia is above the beak with almost no area beneath, while that of Obolella is above
a well-defined false area, and that of Trematobolus is more in advance of the beak.

OBOLELLA ASIATICA Walcott.

Plate LV, figures 6, 6a.

Obolella asiatica Waucort, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 297. (Described and discussed as below as a new
species. )

General form broad, ovai, with the ventral valve showing a tendency to become bluntly
acuminate. Valves gently convex. Surface of shell marked by concentric, raised lines of
growth that form the front edge of narrow lamelle of varying width; the raised lines are highest
in front, which gives an imbricated appearance to the surface; fine concentric striz occur on
the mterspaces between the raised lines. Shell strong, apparently calcareous.

OBOLELLIDA. 589

The specimens occur in a compact, bluish-gray oolitic limestone. None of them show the
area or interior of the valves. The reference to Obolella is based on the general form and calca-
reous shell. The shells vary in size from 3 to 5 mm.

Obolella asiatica may be compared with young shells of O. crassa. Its broadly elliptical
form and slight convexity distinguish it from other species of the genus.

It may be that if material is found showing the interior valves the generic reference will be
changed; but with the data now available, the reference is to Obolella.

The geological horizon is in some doubt, as the specimens were found in a block of river
drift limestone. The associated fragments of trilobites are too indefinite for determination.
Obolella is a Lower Cambrian genus as far as known, and other blocks of river drift limestone
at the same locality contained fragments of Redlichia, so the reference of the species is made to
the Lower Cambrian. By error O. asiatica was included in the list of the Middle Cambrian
fossils of China [Walcott, 1905b, p. 5].

FORMATION AND LOCALITY.—Lower Cambrian: (€32/) Limestone bowlder collected in river drift 1 mile (1.6 km.)
south of Chonpinghien, on Nankiang River, southern Shensi; and (€17) ferruginous limestone nodules in the brown
sandy shales at the top of the Manto shale [Blackwelder, 1907a, p. 27 (list of fossils at top of page) and fig. 6 (bed 15),
p. 25], at Changhia, Shantung; both in China.

OBOLELLA ATLANTICA Walcott.

v Text figure 51, page 590; Plate LV, figures 1, lai.

Obolella crassa SHALER and Forrsre [not (Haut)], 1888, Bull. Mus. Comp. Zool. Harvard Coll., whole ser. 16, No. 2

(geol. ser. 2), p. 27, Pl. I, figs. lat. (Described.)

Obolella sp. SHALER and Forrste, 1888, idem, pp. 27-28, Pl. I, figs. 2a-c. (Described.)
~ Obolella atlantica Waucorr, 1890, Proc. U. S. Nat. Mus. for 1889, vol. 12, p. 36. (Characterized.)
Obolella atlantica Watcort, 1891, Tenth Ann. Rept. U.S. Geol. Survey, p. 611, Pl. LX XT, figs. 1, la-c. (Copies Wal-
cott, 1890, p. 36. Figs. 1 and 1b are copied in this monograph, Pl. LV, figs. 1b and Ic, respectively. Figs. la
and Je were slightly altered before they were used in this monograph, Pl. LV, figs. li and 1h, respectively.)
Obolella atlantica Walcott, MarrHEw, 1899, Trans. Roy. Soc. Canada for 1899, 2d ser., vol. 5, sec. 4, No.3, p.70. (Copies
Walcott, 1890, p. 36, and discusses species.)
Obolella atlantica Walcott, Burr, 1900, American Geologist, vol. 25, p. 47. (Discussed.)
Obolella atlantica Walcott, GraBau, 1900, Occas. Papers, Boston Soc. Nat. Hist., No. 4, vol. 1, pt. 3, pp. 620-621, Pl.

XXXIV, figs. 3a-b. (Described.)

Obolella crassa Shaler and Foerste, GorHaAm [not (Hatt)], 1905, Bull. Roger Williams Park Museum, No. 9, Pl. I, figs.
laf. (No text reference. Figs. la-f are copied from Shaler and Foerste, 1888, Pl. I, figs. la-f.)

Obolella atlantica Walcott, GorHAM, 1905, idem, PI. I, figs. 2a-c. (Notextreference. Figs. 2a-c are copied from Shaler
and Foerste, 1888, Pl. I, figs. 2a-c, respectively.)

Obolella atlantica Walcott, GraBau and Sumer, 1907, North American Index Fossils, vol. 1, p. 188, figs. 222a-d.

(Described. Figs. 222a-d are copied from Walcott, 1891la, Pl. LXXI, figs. 1, la-c, respectively.)

General form ovate, with ventral valve obtusely acuminate im the uncompressed speci-
mens; dorsal valve nearly circular, with the transverse diameter the greatest in the best pre-
served shells (Pl. LV, figs. 1h and 1i). Valves moderately convex. Surface of the shell marked
by concentric strie and more or less imbricating lines of growth; fine radiating striz that are
sometimes raised lines strongly mark most shells, although in some instances the striz are absent,
probably from having been worn away by abrasion. When the imbricating lamelle of the shell
are broken the surface has the appearance shown by figure 1c.

The shells from the limestones of Manuels Brook appear to be relatively thick and formed
of several layers, the lamellz being arranged so as to terminate slightly oblique to the outer
surface, thus forming the foundation for the imbricating lmes of growth. The Smith Point .
material shows only casts of the outer and inner surfaces, as do most of the specimens from
North Attleboro. The thickening of the outer portions of the shell by the growth of the
oblique lamelle forms a strong interior margin which is usually flat (Pl. LV, figs. 1a and 1h),
but it is sometimes oblique to the plane of the edges of the valves (fig. la). The ventral valves
average about 5 mm. in length, the largest is 8 mm.; the dorsal valve is a little shorter than the
ventral.

590 CAMBRIAN BRACHIOPODA.

The area of the ventral valve is low and rises from the edge of the valve to meet the beak at
an angle of 30° to 45°; it extends well out on the cardinal slopes before merging into them; a
narrow furrow divides it midway.

The anterior margin of the area adjoining the false pedicle furrow forms a tooth or knob-
like projection (PI. LV, fig. le) that forms a deep recess next to the cast of the pedicle tube in
the casts of the interior of the ventral valve (fig. 1f). The surface of the area is marked by fine
transverse striz. On each side of the pedicle tube there is a strong undercut which in the cast
is replaced by a toothlike projection. The area of the dorsal valve extends nearly as far out
on the cardinal slopes as that of the ventral; it is marked midway in the cast by two ridges
that converge toward the median line at the posterior margin; these ridges represent furrows
such as occur on the areas of some species of Obolus and Lingulella at the side of the flexure
lines (Lingulella acutangula (Roemer), Pl. XVII, fig. 1h). They are also present in the dorsal
valve of Obolella chromatica Billings.

The pedicle tube or foramen is beautifully shown m numerous casts of the ventral valve.
When the shells are compressed the cast of the tube rests so nearly on the area that one is led
to doubt the existence of shell between the area and the tube. (See Pl. LV, figs. 1f, 1g, 3c.)
In uncompressed specimens the cast of the tube extends upward and backward as shown
by figure 1h. The cast shows a minute apex and trumpet-shaped base. None of the speci-
mens show the exterior foraminal opening, nor has it been seen in any species of the genus.

The strong pedicle furrow shown on the cardinal area in Plate
LV, figure 1e, does not exist on the specimen, except as indicated
by two faint lines. The true pedicle tube opening is shown beneath
the area, as represented in figure 51. This was drawn from the

same specimen as that represented in Plate LV, figure le.

FIGURE 51.—Obolella atlantica Walcott. ; 5
View of ventral valve, tipped back The muscle scars are not well preserved in the material avail-
to show pedicle opening beneath ble for study. The position of the transmedian scars () is indi-
thearea(X 4). (Thesamespecimen bs 2
isshown inadifierent position Pi. cated on each valve; also in the ventral valve the space occupied
LY, fig. le.) The specimen isfrom hy the central, middle lateral, and outside lateral muscle scars.
Locality 50, Lower Cambrian shales a A 2
at Smith Sound, Trinity Bay, New- Of the vascular markings the main sinuses of the ventral
Ce) an) co mpNelve ave tairky «welll shovwn, also the outlines of the parietal scar

o. 519482). : : ae Oukes
(Pl. LV, fig. 1g). The presence of a short median ridge is indicated

on a cast of the dorsal valve (fig. 13).

Observations.—This small but very interesting species is most nearly related to O. chro-
matica Billings. It is nearly the same size, has the same type of shell structure, and probably
the same surface characters. It differs in being less convex, in having a more transverse dorsal
valve, less elongate ventral valve, and the narrower marginal border on the inside of the shell,
as shown by comparing Plate LV, figure 1h, with Plate LIV, figure th.

The separated valves occur in immense numbers in the shales above the limestone on
Smith Point and they are also abundant in a ferruginous limestone at Manuels. The mode
of occurrence of the species is very much like that of O. chromatica, of which it appears to be
the Atlantic coast province representative; hence the specific name.

FORMATION AND LOCALITY.—Lower Cambrian: (50) Just below the Middle Cambrian in shales on Smith Point;
and (5n) shales about 275 feet (84 m.) below the horizon of Locality 50 on Smith Point; both in Smith Sound,
Trinity Bay, Newfoundland.

(5t) Shale and limestone nodules about 20 feet (6 m.) above the base of the Cambrian, on Redrock Point near

Chapple Cove, Hollywood Point; (41) sandstone [see Walcott, 1891b, p. 260, for position in section] on Manuels Brook;
(41a) limestone [Walcott, 1891b, p. 260] on the mainland beneath Topsail Head; and (5p) limestone 300 feet (91.4 m.)
southeast of the railway station, Manuels; all on Conception Bay, Newfoundland.

(9n and 326e) Dark-purplish siliceous shales on Pearl Street, North Weymouth, Norfolk County; (326f [Burr,
1900, p. 47]) 0.5 mile (0.8 km.) south of North Weymouth, Norfolk County; and (326d) station 2 of Grabau [1900,
p. 610], near North Attleboro, Bristol County; all in Massachusetts.

Specimens compared with this species occur at the following locality:

Lower Cambrian: (59m) Weisner quartzite in the Roan iron mine, Bartow County, Georgia.

;
;
%
:

Ne —————————

ae

a

/

OBOLELLID. I

OBOLELLA cHROMATICA Billings.
a Plate LIV, figures 1, la-i.

Obolella chromatica Brnutnas, 1861, Geo!. Survey Canada, Paleozoic Fossils, vol. 1, pp. 7-8, figs. 7a-d. (Described
and discussed as a new species.)

Obolella chromatica Bruuines, 1861, Report on the Geology of Vermont, vol. 2, p. 947, figs. 346a-d. (Text and figures
copied from preceding reference. )

Obolella chromatica Bitu1nes, 1862, Report on the Economic Geology of Vermont, by Hager, p. 219, figs. 346a-d. (Text
and figures copied from preceding reference. )

Obolella chromatica Brntines, 1863, Geol. Survey Canada, Fifteenth Rept. Progress, p. 284, figs. 288a-d. (No text
reference. Figs. 288a-d are copied from Billings, 1861b, p. 7, figs. 7a-d, respectively.)

Obolella chromatica Billings, Haut, 1863, Sixteenth Ann. Rept. New York State Cab. Nat. Hist., p. 132, text figure.
(Mentioned. The text figure is copied from Billings, 1861h, p. 7, fig. 7c.)

Obolella chromatica Billings, Hatx, 1867, Trans. Albany Inst., vol. 5, p.110. (Text and figure copied from Hall, 1863,
p. 132.) ,

Obolella chromatica Bintines, 1876, Am. Jour. Sci., 3d ser., vol. 11, pp. 176-178, figs. 1, 2, 3, p. 176; and figs. 4a-d,
p- 177. (Described and discussed. Figs. 4a-d are copied from Billings, 1861h, p. 7, figs. 7a-d, respectively. )

Obolella chromatica Billings, Forp, 1881, Am. Jour. Sci., 3d ser., vol. 21, p. 133, figs. 3 and 4. (Compared with
O. crassa. Figs. 3 and 4 are drawn from the figures given by Billings, 1876, figs. 1 and 3, p. 176.)

Obolella chromatica Billings, Waxcorr, 1886, Bull. U. S. Geol. Survey No. 30, figs. 9 and 10, p. 110 and p. 112, Pl.
XI, figs. 1, la-b. (Copies Billings, 1861b, p. 7, and 1876, pp. 176-177. Figs. 9 and 10 are copied from Billings,
1876, figs. 1 and 3, p.176. The specimen represented by fig. 1b is redrawn in this monograph, Pl. LIV, fig. 1h.)

~Obolella circe Billings, WAucorv (in part), 1886, idem, p. 118, Pl. X, fig. 3 (not fig. 3a). (Original description, Billings,

1872a, pp. 219-220, of Obolella circe copied. The specimen represented by fig. 3 is redrawn in this monograph,
Pl. LIV, fig. li. Fig. 3a represents a specimen of Quebecia circe.)

~ Obolella chromatica Billings, Waxcorr, 1891, Tenth Ann. Rept. U. S. Geol. Survey, p. 611, Pl. LX XI, figs. 2, 2a-b.

(Mentioned. Figs. 2, 2a-b are copied from Walcott, 1886b, Pl. XI, figs. 1, la-b, respectively.)

-Obolella circe Billings, Waucort, 1891, idem, p. 611, Pl. LX XI, fig. 3 (mot fig. 3a). (Mentioned. Fig. 3 is copied

from Walcott, 1886b, Pl. X, fig. 3. Fig. 3a represents a specimen of Quebecia circe.)

Obolella chromatica Billings, Hatt and CrarKe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, p. 67, figs.
28 and 29. (Mentioned in the text. Figs. 28 and 29 are copied from Billings, 1876, figs. 1 and 3, respectively,
p. 176.)

Obolella chromatica Billings, Waucorr, 1899, Mon. U. 8. Geol. Survey, vol. 32, pt. 2, p. 446. (Note on generic rela-
tions.)

Obolella chromatica Billings, Watcorr, 1905, Proc. U.S. Nat. Mus., vol. 28, p. 313. (Copied from Walcott, 1899, p. 446.)

General form ovate, with ventral valve obtusely acuminate; dorsal valve broadly rounded,
with a tendency to become subacuminate in most specimens. Valves rather strongly convex,
with the beak of the ventral valve raised above the plane of the posterior margin, but usually
below the greatest elevation of the valve. The beak is slightly incurved over the area of the
ventral valve, and that of the dorsal valve terminates at the posterior margin, or may be

_ very slightly curved over it.

Surface of the shell marked by concentric striz and lines of growth and fine radiating
strie. The latter are usually absent either from the exfoliation of the outer layer of the shell,
or from having been abraded before the shell was embedded in sediment. Shell rather thick
and formed of several layers or lamelle within a thin outer layer. The outer layer usually
adheres to the matrix, and the inner layers have been so replaced by calcareous matter that
the shell appears to be solid. In a few examples the individual layers are preserved, and the
oblique lamellz, encircling the anterior portions of the valves, form imbricating lines where
the outer layer has been removed. Billings [1861c, p. 947] described the shell as breaking
with a granular fracture, and when weathered as having a tendency to fibrous exfoliation,
which is true for the specimens in which the original structure is lost.

The area of the ventral valve is usually lower than the greatest elevation of the surface
(Pl. LIV, fig. 1a), but it may be as high as any portion of it (fig. 1e); it projects backward at an
angle varying from 45° to 70°. Billings states 45° to 60° from material he studied. The area
is divided midway by a narrow pseudo-pedicle furrow (p, fig. 1f). The area of the dorsal
valve is well defined in the cast (fig. 1g) and much like that of O. crassa (Hall) (fig. 2k) and O.
atlantica Walcott (P1.LV,fig. 11). The two ridges on the cast that converge toward the posterior
margin are broader than in any other species except O.? lindstrémi Walcott (PI. LV, fig. 4a).

592 CAMBRIAN BRACHIOPODA.

The position of the depressions (a) these ridges filled on the area is shown by figures 1h, 11;
they are triangular areas on each side of a raised, central, triangular space that corresponds
in position to the pedicle furrow in species like Lingulella (Lingulepis) acwminata (Conrad)
(Pl. XLII, fig. 2a). In Obolus apollinis this portion of the area is sometimes slightly elevated,
with a depressed furrow on either side (Pl. VII, figs. 6, 7). The cast of the cylindroconicat
pedicle tube or foramen has been observed in a cast of the interior of the ventral valve (fig. 1e).
This is best seen in Obolella atlantica (Pl. LV, figs. 1f, lg, 1h). The external foraminal opening
has not been observed.

The muscle scars are unfortunately not well preserved. The general position of the trans-
median and anterior laterals is shown in the ventral and dorsal valves (i, j, Pl. LV, figs. 1f, 1¢);
the centrals (h) and the anterior laterals (j) in the dorsal valve (fig. 1h). The position of the
central, middle, and outside lateral muscle scars is indicated in the ventral valve by the outline
of the visceral cavity (v) as shown on figures le, 1f, but no individual scars can be determined.
The outside and middle laterals of the dorsal valve are merged with the transmedian in all
the specimens showing them at all; this is undoubtedly owing to the poor preservation of the
specimens.

The main trunks of the vascular sinuses are fairly well shown in both valves; also the
outline of the parietal scar between the sinuses. A rather strong median ridge occurs in the
posterior half of the dorsal valve on which the small anterior lateral muscle scars are situated
(Pl. LIV, figs. 1g).

Observations.—When the validity of the genus Obolella was attacked [Hall, 1867, p. 110]
Billings restudied this, the type species, and gave [1876, p. 176] an elaborate description of all
the characters he could determine. Through the kindness of the director of the Geological
Survey of Canada and of Prof. J. F. Whiteaves, I have had the opportunity of studying the
material in the Canadian Survey collection. Prof. Alpheus Hyatt also sent me specimens he
collected at L’Anse au Loup and I found some very good specimens in a small collection in
the United States National Museum, that were not accessible when I illustrated the species
in 1886 [1886b, Pl. XI, figs. 1, la—b] and 1891 [1891a, Pl. LXXI, figs. 2, 2a—b]. Among the
new characters discovered are: (a) the narrow pseudo-pedicle groove; (b) the cast of the
cylindroconical pedicle tube or foramen; (c) the character of the area of the ventral valve;
(d) the vascular impressions of the interior of the ventral valve; these taken in connection
with the features shown by O. atlantvca Walcott establishes the genus Obolella as distinct from
Obolus and Dicellomus.

The species O. chromatica Billings is about the same size as O. atlantica, but it differs in
outline, convexity, and details of the areas of both valves. I know of no other species with
which it is necessary to compare its specific characters. It is in association with Olenellus
thompsom and other fossils characteristic of the upper portion of the Lower Cambrian fauna
in the Gulf of St. Lawrence and the Lake Champlain region. The bits of limestone brought
from Labrador show great numbers of the separated alltes, suelo that they occur in
large numbers in one or more layers.

Von Toll [1899, p. 27, Pl. I, fig. 27] illustrates a specimen from 3 miles (4.8 km.) beyond
Bestjachskaja station, on ben ever. Siberia, which he compares with Obolella chromatica
Billings. It is too imperfect to determine with any degree of certainty what it may be.

FoRMATION AND LOCALITY.—Lower Cambrian: (392a) Limestones at L’ Anse au Loup, on the north shore of the
Straits of Belleisle; (392c [Billings, 1872a, p. 218]) at the Straits of Belleisle; and (3921) arenaceous limestone at
Point Amour, Straits of Belleisle; all in Labrador.

(814f) Limestone of B7 of the section at Bonne Bay [Walcott, 1891b, p. 255], Newfoundland.

(338p) Sandy limestone one-fourth mile (0.4 km.) northwest of schoolhouse No. 7 in Greenwich, Cambridge
quadrangle (U.S. Geol. Survey), Washington County, New York.

OBOLELLA CRASSA (Hall).

Text figure 14, page 299; Plate LIV, figures 2, 2a-n.

Orbicula ? crassa Hat, 1847, Nat. Hist. New York, Paleontology, vol. 1, p. 290, Pl. LX XIX, fig. 8a. (Described.)
Avicula ? desyuamata Hatt, 1847, idem, p. 292, Pl. LX XX, figs. 3a and 3b. (Described.)

OBOLELLID. 593

Obolella (Orbicula?) crassa (Hall), Forp, 1871, Am. Jour. Sci., 3d ser., vol. 2, p. 33. (Merely changes generic refer-
ence.

Obolella a (Hall), Burnes, 1872, Canadian Naturalist, 2d ser., vol. 6, No. 2, p. 218. (New locality mentioned.)

Obolella desquamata (Hall), Brtres, 1872, idem, p. 218, fig. 6, p. 217. (New locality mentioned.)

Obolella crassa (Hall), Brtrnes, 1872, Am. Jour. Sci., 3d ser., vol. 3, p. 356. (Copy of Billings, 1872a, p. 218.)

Obolella desquamata (Hall), Brotines, 1872, idem, p. 356, fig. 6, p. 355. (Copy of Billings, 1872a, p. 218, and fig. 6,
p- 217.)

Dicellomus crassa Hat, 1873, Twenty-third Ann. Rept. New York State Cab. Nat. Hist., p. 246, Pl. XIII, figs. 6-9.
(Generic reference changed.)

Obolella crassa (Hall), Forp, 1878, Am. Jour. Sci., 3d ser., vol. 15, p. 128. (Described and discussed. )

Obolelia crassa (Hall), Forp, 1881, idem, vol. 21, pp. 131-183, figs. land 2. (Described and discussed.)

> Obolella chromatica (Hall), Waxcorr, 1885, idem, vol. 29, pp. 115 and 117; figs. 1 and 2, p. 116. (Mentioned in the
text. Figs. 1 and 2 are copied from Ford, 1881, figs. 1 and 2, respectively, p. 131. They represent Obolella
crassa and are wrongly referred to in the text, pp. 115 and 117, as Obolella chromatica.)

Obolella crassa (Hall), Waxcorr, 1885, idem, vol. 30, p. 21. (Correction of error on pp. 115 and 117 of preceding
reference. ) ;

Obolella crassa (Hall), Forp, 1886, idem, vol. 31, fig. 2, p. 466. (No ‘text reference. Fig. 2 is drawn from the speci-
men figured by Ford, 1881, fig. 1, p. 131.)

Obolella crassa (Hall), Watcort, 1886, Bull. U. S. Geol. Survey No. 30, p. 114, Pl. X, figs. 1, la-t. (Copies Hall,
1847, p. 290; Ford, 1878, p. 128; and Ford, 1881, pp. 131-133; and discusses species. Figs. 1d and lf are drawn
from the specimens figured by Ford, 1881, figs. 2 and 1, respectively, p. 131. The specimen represented by
fig. 1c is redrawn in this monograph, Pl. LIV, fig. 21.)

Obolella crassa (Hall), Waxcorr, 1891, Tenth Ann. Rept. U. S. Geol. Survey, p. 612, Pl. LXXT, figs. 4, 4a-f. (New
locality mentioned. Figs. 4, 4a-f are copied from Walcott, 1886b, Pl. X, figs. 1, laf, respectively.)

Obolella circe? Watcotr [not Burnes], 1891, idem, fig. 62, p. 611. (No text reference.)

Obolella crassa (Hall), Harn and CrarKe, 1892, Eleventh Ann. Rept. State Geologist New York for 1891, Pl. III, figs.
5-7. (No text reference.)

Obolella crassa (Hall), Harnand CrarKe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, p. 70, Pl. I, figs. 31-36.
(Discussed. Fig. 33 is drawn from the specimen figured by Hall, 1847, Pl. LXXX, figs. 3a-b. Figs. 32, 36,
and 34 are copied from figs. 5-7, respectively, of the preceding reference.)

Obolelia crassa (Hall)?, GraBav, 1900, Occas. Papers Boston Soc. Nat. Hist., No. 4, vol. 1, pt. 3, pp. 619-620, Pl. XX XT,
fig. 3. (Described.)

Obolella crassa (Hall), Watcorr, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 321. (Discussed.)

Obolella crassa (Hall), Grapau and Sumer, 1907, North American Index Fossils, vol. 1, pp. 188-189, figs. 222e-g,
p. 188. (Described. Figs. 222e-g are copied from Walcott, 1886b, Pl. X, figs. 1, le, and Ic, respectively.)

General form ovate to suborbicular, with the ventral valve bluntly acuminate in some
examples. Considerable variation in outline occurs, as is shown by Plate LIV, figures 2, 2a,
2b of the ventral valve, and 2k, 21 of the dorsal valve. Valves moderately convex, with the
beak of the ventral valve depressed below the greatest elevation of the surface and slightly
curved over the low area; the beak of the dorsal valve terminates at the posterior margin.

Surface of the shell marked by rather strong, concentric striz and lines of growth that
interrupt the continuity of fine radiating lines; it is rarely that the surface is well preserved;
usually the shells are smooth as though they had been abraded. Shell rather thick, and formed
of several layers or lamelle that are more or less oblique to a thin outer layer; the short oblique
lamelle encircling the anterior portion ofthe valves form imbricating lines when the outer
surface is removed (Pl. LIV, fig. 2b). Very few shells show the shell structure; usually the
calcareous matter has so far replaced the origmal shell that there is only a solid calcareous,
granular, or calcite shell, as shown by the broken section (fig. 2f). The weathered surface
often has a fibrous appearance similar to that of the shell of Obolella chromatica Billings.

The area of the ventral valve is usually short, but it varies considerably in this respect
(PL. LIV, figs. 2¢, 2h, 2j). It overhangs the posterior margin at an angle varying from 45° to 70°
and extends well out onto the cardinal slopes; fine strie of growth parallel to the margin cross
the area and pass into and across the central furrow; a narrow furrow divides the area midway
(Pl. LIV, figs. 22, 2h, and 2]). The specimen represented by figure 2h has a rounded cardinal
area and a very shallow median furrow; a small pedicle opening is outlined beneath the
rounded area, but it is not shown in the illustration. A tendency of the inner point of the
area next to the furrow to thicken and project forward into the cavity of the shell is found
in several specimens, but it is not as pronounced as in Obolella atlantica Walcott. The area

62667°—vot 51, ptr 1—12——38

594. CAMBRIAN BRACHIOPODA.

of the dorsal valve is flat and marked midway by a slightly raised triangular space with
depressed triangular spaces on each side; what appear to be flexure lines cross the area very
much as they do in the area of the dorsal valve of Obolus apollinis Eichwald. Pedicle tube
or foramen of ventral valve small, cylindroconical. It has been observed in a broken section
of the posterior portion of one shell (Pl. LIV, fig. 2n). The external forammal opening is a
little in advance of the extreme end of the beak.

The muscle scars are more clearly shown in O. crassa than in any other species of the
genus. The transmedians (i) in both valves are near the margin of the area and close to the
main vascular sinuses; the outside and middle laterals (1) of the dorsal valve can not be sep-
arated, but their position a little in advance and slightly outside of the transmedian is well
indicated on the casts of the interior (Pl. LIV, figs. 2k and 21); the anterior laterals of the ventral
valve are shown by figure 2h at j, a little m advance and outside of the transmedian, also in the
dorsal valve as small oval scars each side of the median line near the center of the shell; the
central scars (h) of the dorsal valve are elongate, oval, and situated on the mner edge of a
groove bounding the visceral cavity, about one-fourth of the distance between the anterior
lateral scars and the posterior margin of the shell; the central, middle lateral, and outside
lateral scars of the ventral valve have not been differentiated; the area (c) m which they should
occur (Pl. LIV, figs. 2g and 2h) is clearly outlimed in a number of specimens; the pedicle and
umbonal scars have not been observed.

The main vascular sinuses of the ventral valve are strongly marked and extend forward
well toward the front margin of the shell; they vary in form and position in different shells
largely on account of the thickness and manner of deposit of the shell substance. The figures
2¢-j illustrate better than any description I can give the character of the smuses and the prin-
cipal variations as far as known to me. In the dorsal valve the main sinuses extend farther
out from the median line than im the ventral, but they are small and inconspicuous when com-
pared with the latter or with the strongly impressed grooves on each side of the visceral cavity.
The latter grooves rise to give the peculiar ridges having the appearance of frog legs that are
so strongly marked in the cast of the dorsal valve of Obolus (Lingulobolus) spissus (Billings)
(Pl. XVI, fig. 2d).

Observations.—In a former paper [1886b, pp. 114-116] I have quoted the descriptions of
this species by Hall and Ford. With the material now available and our more detailed infor-
mation of the genus, it is unnecessary to repeat or to comment on those descriptions or on
the slight additions made by myself, except the reference made to Avicula? desquamata Hall.

Billings [1861b, p. 7] thought that Avicula? desquamata Hall might be referred to Obolella,
and Ford [1871, p. 33] referred Orbicula? crassa Hall to the same genus. Later [1878, p. 128]
the latter observer placed Avicula? desyuamata as a synonym of O. crassa, saying:

The species known as Obolella crassa of the Troy beds may also be briefly noticed in this connection. It includes
the species already widely known under the name of O. desquamata from the same locality, this latter, as may be shown,
having been founded upon the dorsal valve of the former. The ventral valve is always more acutely pointed at the
beak than the dorsal, but beyond this feature there is nothing, so far as I have been able to discover, by which they
may be distinguished from each other externally. The surface of each when perfect is both radiately and concen-
trically striated. Asa rule, however, the imbricating edges of the successive layers of growth are the only markings
visible.

Obolella crassa is one of the large species of the genus. There is no closely allied species on
the American Continent, but O. mobergi, of Sweden, may be considered as such in the Sean-
dinavian Cambrian faunas. Some examples of the outer surface of O. moberqi resemble O.
crassa, but a careful comparison of the form and also of the mterior of the valves shows striking
specific differences (Pls. LIV and LV). The presence of a well-marked median furrow on the
area of the ventral valve and a relatively small pedicle tube are noticeable features in O. crassa.

Obolella crassa is very abundant in some of the limestone layers interbedded im the siliceous
shales at Troy, New York. It also occurs im the limestone conglomerate of the same region.
It is associated with the Elliptocephala asaphoides fauna in the Hudson Valley, and a
similar fauna is found in the limestone bowlders of the Bic conglomerate in the St. Lawrence

.
:

OBOLELLID~. 595

Valley. I have found no traces of it in the Atlantic province Cambrian formations. Strati-
graphically, it is, I believe, the oldest representative of its genus in America.

FORMATION AND LOCALITY.—Lower Cambrian: (392c [Billings, 1872a, p. 218]) At the Straits of Belleisle,
Labrador.

(56b) Limestone bowlder in conglomerate, on the south shore of Orleans Island, below Quebec; (20) limestone
bowlders in conglomerate, on shore at east entrance to harbor at Bic, Rimouski County; and (319b) conglomeratic
limestones containing Olenellus ?, at St. Simon; all in Quebec, Canada.

(319k) Calcareous somdtione near the ibnse of the section west of Parker’s quarry, on cliff overlooking Lake
Champlain, east of Georgia, Franklin County, Vermont.

(2b) Limestone just north of Beman Park, in the northeastern part of the city of Troy, Troy quadrangle (U.S.
Geol. Survey); (27) even-bedded and conglomerate limestones on the ridge in the eastern suburb of Troy, Troy
quadrangle (U. S. Geol. Survey); (338q [ Hall, 1847, p. 290]) calcareous beds 2 miles (3.2 km.) northeast of Troy, Troy
quadrangle (U. S. Geol: Survey); (27a) reddish sandstone about 1 mile (1.6 km.) east of Lansingburg, north of Troy,
Cohoes quadrangle (U. S. Geol. Survey); and (29a) limestone 1 mile (1.6 km.) below the New sore Cisne Railroad
depot at Schodack; all in Rensselaer County, New York.

(3380) Shale on Moses Hill, 2 miles (3.2 km.) west of North Greenwich; and (35) limestones 1.5 miles (2.4 km.)
north of Bald Mountain; both in the Schuylerville quadrangle (U. S. Geol. Survey), Washington County,6 New
York.

(826d) “‘Station 2”’ of Grabau [1900, p. 610] near North Attleboro, Bristol County; and (326g [Grabau, 1900, p-
620]) limestones at East Point, Nahant, Essex County; both in Massachusetts.

Specimens that are somewhat doubtfully referred to this species occur at the following
localities: .

Lower Cambrian: (50a) Sandstone 2 miles (3.2 km.) northwest of York, York County; and (12v) sandstone
above the quartzite 1 mile (1.6 km.) west of Fruitville on Little Conestoga Creek, Manheim township, Lancaster

County; both in Pennsylvania.
(59m) Weisner quartzite in the Roan iron mine, Bartow County, Georgia.

OBOLELLA CRASSA ELONGATA N. Var.
Plate LV, figures 5, 5a.

In the collections from St. Simon there is an oval or elongate ovate form to which it
appears to be desirable to give a varietal name. Its surface is marked by stronger concentric
lines of growth than usually occur on the less elongate shells of O. crassa (Hall), and the valves,
especially the dorsal, are much more elongate than those of O. crassa. One ventral valve of
the latter species from Troy, New York, is nearly as elongate (Pl. LIV, fig. 2a), but it is broader
on the posterior half of the shell than those from St. Simon referred to the variety elongata.

ForMATION AND LocALiry.—Lower Cambrian: (319b) Conglomeratic limestones containing Olenellus?, St.
Simon, Province of Quebec, Canada.

OBOLELLA GROOMI Matley.
4 Text figure 52, page 596.

Obolelia(?) groom MattEy, 1902, Quart. Jour. Geol. Soc. London, vol. 58, pt. 1, pp. 187 and 189, figs. 1-2, p. 137.
(Described and discussed as a new species, see below for copy. Fig. 1 is copied on p. 596 as fig. 52.)

The original description by Matley follows:

Shell oval, moderately convex, about as long as wide, widest toward the front, which is moderately to well rounded.
Lateral margins straight or slightly convex, converging posteriorly to form a rounded beak. Hinge-area absent, or
not well defined. Sides usually somewhat deflected. Surface covered by about thirty small but well-marked, con-
centric, rugose ridges. No radial strize. Casts of the interior show nothing but very faint traces of markings.

About 4.5 mm. long by 5 mm. wide. Type in Professor Groom’s collection. Other specimens measure:

Length. Width.
mm mm.
Wo Veco Ses 5.5
ONOk neces 5
CDE areeaper 4.75

aThe species also occurs at igen 2d. b This species also occurs at Locality 20.

596 CAMBRIAN BRACHIOPODA.

,

Several specimens of this shell have been collected by Prof. Theodore Groom, in honor of whom the specific name
isgiven. With no knowledge of its internal characters, the generic reference is necessarily provisional, but the species
approaches in outline and external characters some American forms of the genus
Obolella, especially the type species of the genus, O. chromatica Billings, of the
Olenellus zone of Canada, from which, however, it appears to be separated by the
form of the beak and the shape of the umbonal region.

There is little to add to Matley’s description and observations,
except to call attention to the resemblance in general form and
surface of this species to the figure of Obolella crassa elongata on
Plate LV, figure 5. As described and illustrated the species appears

FIGURE 52.—Obolella groomi Matley.
A, A’, Top and side views of a ven- to be a true Obolella.

tralvalve. The figures are copied 4 .
from Matley, aoa 137, fir. ‘th FORMATION AND LOcALITy.—Lower Cambrian: (304c)¢:‘‘Malvern quartzite”

at Raggedstone Hill; and (304d)¢ ‘‘Malvern quartzite” at Midsummer Hill; both
[Groom, 1902, p. 94] in the Malvern Hills, between Herefordshire and Worcestershire, England.

OBOLELLA ? LINDSTROMI Walcott.

Plate LV, figures 4, 4a.

Obolella lindstrémi Waxcort, 1901, Proc. U. S. Nat. Mus., vol. 23, pp. 674-675. (Characterized and discussed essen-
tially as below as a new species.)

This species differs from Obolella mobergi Walcott in the more subacuminate outline of
the valves, the surface characters, and the interior of the dorsal valve. The last, is well
shown by comparing figures 3e and 4a (Pl. LY). Figures 3 and 4 clearly indicate the differ-
ence in surface of the two species. The surface of O.? lindstrémi is much like that of Bicia
gemma (Pl. L, figs. 1a and 1d).

The ventral valve (Pl. LV, fig. 4) occurs in a hard gray sandstone of the Mesonacis torelli
zone, and the cast of the dorsal valve (fig. 4a) is from one of the brown sandstone masses that
occur within the gray sandstone at Sularp. I am not sure that the dorsal valve illustrated
actually belongs to this species, as it is not associated with the typical ventral valve. It
differs from the typical dorsal valves of O. mobergi in being more acuminate, and there is no
corresponding ventral valve associated with it in the material studied.

I take pleasure in naming the species in honor of Dr. G. Lindstrém, to whom all paleon-
tologists are deeply indebted for his many fine contributions to the paleontology of the Silurian
formations of Scandinayia.

FORMATION AND LOCALITY.—Lower Cambrian: (321v) Gray sandstone of the Mesonacis torellt zone at Bjorkelunda,

south of Simrishamn, Province of Christianstad; and (321s) brown sandstone interbedded in gray-sandstone at Sularp,
near Lund, Province of Malméhus; both in Sweden.

OBOLELLA MINOR (Walcott).

Plate LIV, figures 3, 3a-d.

Camerella minor Waxcort, 1890, Proc. U. S. Nat. Mus. for 1889, vol. 12, pp. 36-37. (Described and discussed as a
new species. )

Camarella? minor Waxcorr, 1891, Tenth Ann. Rept. U. S. Geol. Survey, p. 614, Pl. LXXII, figs. 4, 4a-d. (Text
copied from preceding reference. Figs. 4, 4a-d are copied in this monograph, Pl. LIV, figs. 3b, 3, 3c, 3d, and
3a, respectively.)

Camarella minor Walcott, Haut and CrarKe, 1894, Nat. Hist. New York, Paleontology, vol. 8, pt. 2, p. 221. (Char-
acterized and discussed.)

Protorhyncha? minor (Walcott), ScHucHERT, 1897, Bull. U. S. Geol. Survey No. 87, p. 334. (Generic reference changed
and generic relations discussed.)

Obolella minor (Walcott), CLarK and Matuews, 1906, Maryland Geol. Survey, vol. 6, 1906, pt. 1, p. 252, Pl. XVI,
figs. 13 and 14. (No text reference. Figs. 13 and 14 are copied from Walcott, 1891a, Pl. LXXII, figs. 4a and
4c, respectively.)

General form ovate, biconvex. Surface smooth or marked by concentric lines and varices

of growth. Ventral valve subacuminate, moderately convex, with the most elevated portion
at the umbo, which curves downward toward the small apex; the posterior or umbonal third

@ Neither Groom [1902, p. 94] nor Matley [1902, p. 137] states which of these localities is the type locality.

OBOLELLID AL. 597

of the valve is usually more or less tumid, a ridge of growth separating it from the anterior
portion of the shell; area nearly on the plane of the margins of the valve and divided midway
by a narrow, deep, pedicle furrow; casts of the interior show that the area formed a shelf on
each side of the pedicle furrow. Dorsal valve transversely ovate; a narrow, short area and
a slight median ridge are indicated on a cast of the interior.

This shell is small. A large ventral valve measures, length, 7 mm.; width, 6 mm.; a dorsal
valve, length, 6 mm.; width, 6.5 mm.

Observations.—The characters of this little shell, as far as they are known, are those of
Obolella. In my original description I gave an erroneous interpretation to the cast of the
interior of the ventral valve. At that time I did not know much of the interior of Obdolella,
and also considered the cast of the space beneath the area beside the pedicle groove as indicating
the existence of plates as in Pentamerus. In the absence of the shell or fine casts it is impossi-
ble to determine conclusively whether a foraminal tube existed, as in Obolella atlantica Walcott,
or not; one cast indicates that such was the case. The form and long area distinguish this ,
from other species of the genus.

ForMATION AND LOCALITY.—Lower Cambrian: (16f) Sandstone at the mouth of Little Antietam Creek, near
Eakles Mills; (47d) sandstones 1 mile (1.6 km.) east-southeast of Smithsburg; (4’7e) sandstone on Observatory Hill,
2 miles (3.2 km.) south of Keedysville; and (47f) sandstone at Eakles Mills, 2 miles (3.2 km.) south of Keedysville;
all in Washington County, Maryland.

(82) Sandstone on the south slope of Stissing Mountain, Dutchess County, New York.

(49b) Sandstone 2 miles (3.2 km.) northwest of Emigsville, York County; (49c) sandstone in ridge just north of
the railway station in Emigsville, York County; (49d) sandstone 3 miles (4.8 km.) east of Waynesboro, Franklin
County; (49e) sandstone 1 mile (1.6 km.) south of Mount Zion Church, and 4 miles (6.4 km.) northeast of York, York
County; and (49f)@ sandstones of Mount Holly Gap, South Mountain, Cumberland County; all in Pennsylvania.

(47a) Sandstone on the southwest side of Sallings Mountain, 2 miles (3.2 km.) east of Natural Bridge, Rockbridge
County, Virginia. ‘

(47c) Sandstone 2 miles (3.2 km.) west of Harpers Ferry, Jefferson County, West Virginia.

OBOLELLA MOBERGI Walcott.

“<i Plate LV, figures 3, 3a-f.

? Obolus? sp. KsERuLF, 1873, Om Skuringsmerker, Glacialformationen, Terrasser, og Strandlinier, etc., 2: Sparagmit-
fjeldet, p. 83, figs. 10 and 11. (No text reference.)

Obolella mobergi Waucorr, 1901, Proc. U. S. Nat. Mus., vol. 23, pp. 673-674. (Described and discussed as below as a
new species.)

General form ovate, with the ventral valve subacuminate and the dorsal valve obtusely sub-
acuminate; valves moderately convex; beak of the ventral valve slightly elevated above the
plane of the shell; beak of the dorsal valve curved down to the plane of the margin. Surface
of the shell marked by concentric lines and striz of growth, and in some examples by rather
strong, radiating, broken, and slightly irregular raised lines of the same character as those of
Bicia gemma (Billings). The shell is formed of a thin outer layer, and numerous inner layers or
lamellze over the anterior half of the shell. These imbricating inner lamelle are oblique to the
outer layer, very much as in Obolella (Glyptias) favosa (Linnarsson).

A ventral valve 10 mm. in length has a width of 9mm. A dorsal valve 9 mm. long has the
same width.

The area of the ventral valve is of medium length and tipped back from the edge of the
valve to meet the beak; it extends well out onto the cardinal slopes, and is divided midway by
a narrow furrow. The surface of the area is marked by rather strong transverse striz crossing
the area. On each side of the base of the pedicle tube there is a rather strong undercut which
in the cast is replaced by a marked toothlike projection. The area of the dorsal valve is narrow.
The cast of the pedicle tube or foramen is large, cylindroconical, and encircled hy a number of
rather strong lines of growth (Pl. LV, fig. 3c).

The casts of the interior of the ventral valve show a central visceral area, very much like
that in O. crassa (Hall); also two strongly marked vascular sinuses that extend well into the

aDoubtfully identified from this locality.

598 CAMBRIAN BRACHIOPODA.

middle of the valve. No clearly defined muscle scars are shown on any of the specimens.
Casts of the interior of the dorsal valve give little satisfactory data in relation to the muscle
scars. The cast illustrated by Plate LV, figure 3e, shows a part of the outline of the visceral
area, also the impression of the transmedian muscle scar.

Observations-—This species has been considered as the European representative of O.
crassa (Hall), which occurs at the same relative stratigraphic horizon at Troy, New York.
The Swedish form differs specifically from the American in having a slightly more elongate
pedicle tube and in having the interior thickenings of the area more strongly developed. It
differs from O. atlantica Walcott and O. chromatica Billings in having a much more robust shell
and in many slight details.

Kjerulf [1873, p. 83, figs. 10 and 11] illustrates, without text reference, a form that appears
to be referable to this species. It is found in Locality 324, at Tomten, Norway, in association

with Holmia kjerulfi, Arionellus,
ES and Obolella (Glyptias) favosa.
B’ The specific name was given
in honor of Dr. J. C. Moberg.

FoRMATION AND LocALITy.—Lower
Cambrian: (321v) Gray sandstone of the
Mesonacis torelli zone at Bjorkelunda,
south of Simrishamn, Province of Chris-
tianstad; and (321s) brown sandstone in-
terbedded in gray sandstone at Sularp,
B Cc near Lund, Province of Malméhus; both
in Sweden.

(8v) Shales and dark, calcareous,
ferruginous rock in the upper portion
of the Holmia kjerulfi zone, Ringsaker;
and (324 [Kjerulf, 1873, pp. 73 and 83])
green shales with interbedded calcare-
ous sandstone at Tomten, in Ringsaker;
both in the Province of Hedemarken,
Norway.

D

FiGURE 53.—Obolella vermilionensis n. sp. A, Cast of the interior of a ventral valve, the type
specimen (X 2), from Locality 60b, Lower Cambrian sandstones in Vermilion Pass, Alberta,
Canada (U.S. Nat. Mus. Cat. No. 56606a). B,B’, Top and back views of a dorsal valve
associated with the specimen represented in figure 583A (X 2) (U.S. Nat. Mus. Cat. No.
56606b). C, Ventral valve preserving its shape but from which all traces of shell sub-
stance have been removed (X 2). It is associated with the specimens represented by & : :
figures 53A and 53B (U. S.'Nat. Mus. Cat. No. 56606c). D, Ventral valve from Locality This species 1S represented
14p, Lower Cambrian sandstones near Resting Springs, California (U.S. Nat. Mus. Cat. by numerous easts in a fine-
No. 51964a). E, Associated dorsal valve, Locality 14p (U. S. Nat. Mus. Cat. No. 51964).

OBOLELLA VERMILIONENSIS nN. sp.

Text figures 53A—E.

U

grainedsandstone. General form
suborbicular, slightly transverse. Shells fairly convex and uniformly larger than those of the
other species of the genus.

The beak of the ventral valve is somewhat lower than the greatest elevation of the shell,
and does not reach the posterior margin. Both the beak and the area are, as a rule, poorly pre-
served, but the incurving of the growth lines to form the area is well shown in several specimens.
Interior casts of the ventral valve show traces of vascular sinuses.

The beak of the dorsal valve terminates at the posterior margin, but is raised slightly
above the plane of the margin of the shell.

Shell substance not preserved, but the casts show indications of both radial and concentric
striation.

Observations.—The representatives of this species occur in such widely separated parts of
the Rocky Mountain province as California and British Columbia, but the forms are identical
and are associated in each district with Holmia and Orthotheca.

Obolella crassa approaches this species in the size of some of its specimens, but it is uni-
formly smaller and less convex. Obolella vermilionensis also differs from the former species in
its transverse outline. Further comparison is impossible because of the lack of knowledge as
to the interior of Obolella vermilionensis.

es

OBOLELLID. 599

FORMATION AND LOCALITY.—Lower Cambrian: (60b) About 2,300 feet (702 m.) below the Mount Whyte formation and
200 to 300 feet (61 t0 92m.) above the Lake Louise shale, in the St. Piran sandstone [Walcott, 1908a, p. 4], at Vermilion Pass,
on the Continental Divide between British Columbia and Alberta, west-southwest of Castle, on the Canadian Pacific Railway,
Alberta, Canada.

(53) Sandstones in the lower portion of 3d of the Waucoba Springs section [Walcott, 1908f, pp. 187 and 188], 1 mile
(1.6 km.) east of the Saline Valley road about 2.5 miles (4 km.) east-northeast of Waucoba Springs; (12a) sandstones
of 3b of the Waucoba Springs section [Walcott, 1908f, p. 187], east of the Saline Valley road east of Waucoba Springs;
(14p) sandstone near Resting (Freshwater) Springs, which is in the southwest corner of T. 21 N., R. 8 E., on Amar-
gosa River; (8b) limestone in Tollgate Canyon, about 15 miles (24.2 km.) east of White Pine, White Mountain Range;
and (176) shales and interbedded limestones, between massive limestones carrying Archexocyathus, at the south end
of Deep Spring Valley; all in Inyo County, California.

OBOLELLA WIRRIALPENSIS Etheridge.
Plate LV, figures 7, 7a—b.

Obolella wirrialpensis ErHermex, 1905, Trans. Roy. Soc. South Australia, vol. 29, p. 248, Pl. XXV, figs. 2 and 3.
(Described and discussed as a new species. The specimen represented by fig. 2 is redrawn in this monograph,
Pl. LV, fig. 7b.)

Obolella wirrialpensis calceoloides ETHERIDGE, 1905, idem, p. 249, Pl. X XV, figs. 4-6. (Characterized and discussed
asanew variety. The name placed at the head of the paragraph is ‘‘Obolella sp.,’’ the term calceoloides being
applied to it in the text.)

The original description by Etheridge follows:

Valve (? pedicle) ovate to subquadrate, gently convex, rising dorsally into a small umbo; rounded ventrally and
without emargination; lateral angles rounded. Internal muscle scars hardly at all curved, diverging from one another,
extending far forward, and tapering to a fine point. Surface characters very marked and distinctive, consisting of a
series of clean-cut, flat, concentric steps, the ‘‘tread” of each step practically at right angles to its ‘‘riser;” no concen-
tric or radial striz of any kind.

After a study of the type specimens of this species and several specimens that were worked
out of a block of the limestone received from Mr. Walter Howchin, of the University of Ade-
laide, I have concluded that the variety calceoloides is a narrow form of the species. There
are a number of intermediate forms which render it difficult to separate a distinct variety. The
species resembles Obolella crassa (Hall) in outline and convexity more than any other species
referred to the genus.

The specific name is derived from Wirrialpa, the type locality.

FoRMATION AND LocALITY.—Lower? Cambrian: (315d [Etheridge, 1905, p. 248]) Limestone near Wirrialpa,
Flinders Range, South Australia.

— OBOLELLA? sp. undt.

Obolella cf. atlantica DELGADO, 1904, Communicagdes Commissao Servico Geol. Portugal, tome 5, fase. 2, p. 364, Pl.

IV, fig. 35. (Described in French.)

This form, Delgado states [1904, p. 364], is represented by a single specimen, which he
compares with Obolella atlantuca Walcott. The material is too poor to base a specific deter-
mination upon. The photograph of the cast of the interior of a small ventral valve 4.5 mm.
long and 6 mm. wide indicates that the specimen may be referred to this genus, but it may
belong to Trematobolus, Botsfordia, or an allied genus.

The Obolella maculata referred to by Delgado [1904, p. 364] has in this monograph been
referred to Acrothele villaboimensis.

ForRMATION AND LOCALITY.—Lower Cambrian: (351 [Delgado, 1904, p. 364]) Shales at Monte de Valbom, to the
northeast of Villa Boim, Province of Alemtejo, Portugal.

GLYPTIAS Walcott,” subgenus of OBOLELLA.

Obolella (Glyptias) Waucort, 1901, Proc. U. S. Nat. Mus., vol. 23, p. 675. (Mentioned as below as a new subgenus.)
Obolella (Glyptias) Waucorr, 1908, Smithsonian Misc. Coll., vol. 53, No. 4, Pl. XI, and pp. 142 and 145. (Classifi-
cation of subgenus.)
The subgenus Glyptias is based on the peculiar surface sculpture and the very short area.
Type.—Lingula (2) favosa Linnarsson.

¢ Prior to the definition of this subgenus the type species was described under Lingula ? Linnarsson [1869a, p. 356; 1869b, p. 406].

600 CAMBRIAN BRACHIOPODA.

OBOLELLA (GLYPTIAS) FAVOSA (Linnarsson).
Plate LV, figures 2, 2a-d.

Lingula (2) favosa LinNARSSON, 1869, Ofversigt af K. svensk. Vet.-Akad. Forhandl. for 186), vol. 26, No. 3, pp.
356-357. (Described and discussed in Swedish as a new species.)

Lingula (2) favosa LiINNARSSON, 1869, Geol. Mag., vol. 6, p. 406. (Translation of the preceding reference.)

2? Discina? sp. KyERuLF, 1873, Om Skuringsmerker, Glacialformationen, Terrasser, og Strandlinier, etc., 2: Sparagmit-
fjeldet, p. $3, figs. 12 and 13. (No text reference.)

Obolella (Glyptias) favosa (Linnarsson), Watcort, 1901, Proc. U.S. Nat. Mus., vol. 23, pp. 675-676. (Described and
discussed essentially as below.)

General form ovate, with the ventral valve subacuminate and the dorsal valve obtusely
rounded; valves moderately convex. The dorsal valve is abruptly curved downward at the
beak to the plane of the edge of the shell, while the beak of the ventral valve is slightly above
the margin, the posterior edges of the shell curving up to meet it. Surface of the shell marked
by very fine concentric lines or striz of growth, crossed transversely by undulating, slightly
lamellose lines in almost identically the same manner as in Obolus ( Westonia) stoneanus (Whit-
field) of the Upper Cambrian of Wisconsin (Pl. XXVIII, fig. 2d). When the outer surface
of the shell is exfoliated or worn off by attrition, which is the usual condition, the surface
of the inner layers shows fine radiating and concentric striz. The shell is formed of a very
thin, highly ornamented outer layer and numerous inner layers or lamelle; the latter over the
anterior portions are oblique to the outer layer, and when the shell is partly exfoliated they
appear as imbricating layers very much as in Obolus matinalis Hall).

The largest ventral valve in the collection has a length of 7 mm. and a width of 6 mm.
An associated dorsal valve 6 mm. long has a width of 6.25 mm.

The area of the ventral valve is narrow and rises slightly to meet the beak, which is ele-
vated above the posterior margin. The pedicle tube or foramen is short and small, and, judgmg
from the appearance of the specimens where the beak of the valve is broken away, it opened
near the apex of the beak. On the dorsal valve there is no evidence of a true area except in
the presence of a narrow, thickened rim somewhat like that of the dorsal valve of Bacia gemma
(Billings). None of the muscle scars are shown in the ventral valve. The position of the
central and anterior lateral scars of the dorsal valve is indicated near the outline of the vis-
ceral cavity (Pl. LV, fig. 2c). Of the vascular markings, the main sinuses are clearly shown
in each valve, also the outline of the parietal scar. All that is known of them is well shown on
Plate LY.

Observations.—This beautiful little shell has remained without illustration since Linnarsson
[1869a, p. 356] gave it a name, based on the “‘singular sculpture” of the outer shell. In a
collection made for me by Mr. Schmalensee, a collector in the Geological Survey of Sweden,
there were several specimens showing casts of the interior more or less imperfectly. From
these I was able to ascertain that the shell has the generic characters of Obolella, although
differing from the typical species of that genus in the character of the surface ornamentation.
The outer surface has been seen only on the posterior umbonal portion of the valves in the
shells collected.

Kjerulf [1873, p. 83, figs. 12 and 13] illustrates, without text reference, a form that appears
to be referable to this species. It occurs in Locality 324 at Tomten, Norway, in association
with Obolella mobergi, Holmia kjerulft, and Arionellus.

FoRMATION AND LOCALITY.—Lower Cambrian: (309c) @ ‘‘Fucoid sandstone” at Billingen, east of Skara; and (309d)
“fucoid sandstone” at Lugnds, 8 miles (12.8 km.) south-southeast of Mariestad; both [Linnarsson, 1869a, p. 357] in the
Province of Skaraborg, Sweden.

(324 [Kjerulf, 1873, pp. 73 and 83]) Green shales with interbedded calcareous sandstone at Tomten, in Ringsaker,
near Lake Mjésen, Province of Hedemarken, Norway.

a Specimens from this locality are included in the collections of the United States National Museum.

OBOLELLID. 601

Genus BOTSFORDIA Matthew.

Obolus (Botsfordia) MatrHew, 1891, Trans. Roy. Soc. Canada for 1890, Ist ser., vol. 8, sec. 4, No. 6, p. 148. (Merely
uses the term ‘‘Obolus (Botsfordia) pulcher” in the text.)

Obolus (Botsfordia) MarrHnw, 1892, Trans. Roy. Soc. Canada for 1891, Ist ser., vol. 9, sec. 4, No. 5, p. 63. (Merely
proposed as a new subgenus.)

Lingulella Hatt and CLarkeE (in part), 1892, Eleventh Ann. Rept. State Geologist New York for 1891, pp. 232-233.

fs (The genus Lingulella is described, Lingulella davist being given as the type, but Botsfordia clata is figured
as tke generic illustration on Pl. III.)

Lingulella Haut and CuarKs (in part), 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, pp. 55-59. (The genus
Lingulella is described and discussed, but figures of Obolus (Westonia) ella accompany the text, and Botsfordia
cxlata is figured as the generic illustration on Pl. Il. Species belonging with other genera are also mentioned as
belonging to Lingulelia.)

Mobergia Repuicu, 1899, Mem. Geol. Survey India, Paleontologia Indica, new ser., vol. 1, No. 1, Cambrian Fauna
of the Hastern Salt Range, pp. 5-6. (The description of this new genus is incorporated with that of the new
species ‘‘ Mobergia granulata.’’)

Botsfordia Matthew, Watcort, 1908, Smithsonian Misc. Coll., vol. 53, No. 4, Pl. XI, and pp. 142 and 145. (Classifi-
cation of genus.) \

General form moderately convex, subcircular, with the ventral valve more or less obtusely
acuminate and the dorsal valve oval. Ventral valve with the beak (apex) close to the pos-
terior margin, perforated with a minute pedicle opening that is separated from the posterior
margin by a very short listrium; posterior margin arched above the plane of the side and
front margins of the valves. Dorsal valve with a minute beak at the margin.

Surface with concentric lines and ridges of growth and a more or less regular system of
tubercles resting upon concentric, rounded, regular or irregular, separate or inosculating
ridges; the tuberculated or granulated puriice may cover the entire shell or only a portion
of it; the tubercles may be arranged in regular order, as in Botsfordia pulchra (Matthew) (PI.
LXII), or irregularly, as in B. gremunlitin (Redlich) (Pl. LVII).

The shells are small, rarely exceeding a length of 12 mm. Substance corneous, or phos-
phate of lime and chitin.

Structure of shell lamellated, the mner lamelle being more or less oblique to the outer
layer.

Interior of ventral valve with a small visceral area not exceeding one-half the length of
the valve; the pedicle opening is at the posterior end of the visceral area, where the shell usually
has its greatest thickness. Vascular sinuses strong, and well within the body of the valve.
Muscle scars arranged essentially as in Obolus; the transmedian and anterior lateral are close
to the main vascular sinus and well back toward the posterolateral part of the valve. So
far as known, the centrals and the middle and outside laterals are grouped on each side of the
front of the visceral area.

Interior of dorsal valve much like that of Acrothele, except that the transmedian muscle
scars are separable from the outside and middle lateral scars in one species, Botsfordia gran-
ulata (Redlich); otherwise they appear to be grouped within the cardinal muscle scar. Median
ridge long and prominent; main vascular sinuses well developed and well within the sides
of the valve; visceral area in the adult usually not more than one-half the length of the valve;
central and anterior lateral muscle scars near the center of the valve.

Type.—Obolus pulcher Matthew.

a The synonymy for this genus does not give a complete record of the various genera under which the species now included in Botsfordia were
formerly placed; it gives only those references in which the genus is discussed or described. To complete the ewer! the following mere generic
references are listed:

Orbicula Hall [1847, p. 290]. Lingulella Walcott [1891a, p. 607].

Brachiopode, nouy. gen. [de Verneuiland Bar- Obolus? Hall and Clarke [1892c, pp. 81 and 183].
rande, 1860, p. 536]. Obolus (Botsfordia) Matthew [1894, p. 90; 1895a,

Obolella (Orbicula) Ford [1871, p. 33]. p. 115].

Obolella Billings [1872a, p. 218]. Lingulelia Matthew [1895a, p. 126].

Lingulella Walcott [1886b, p. 95; 1887, p. 199]. Acrothele Pompeckj [1896b, p. 603].

Lingulella? Matthew [1888, p. 28]. Obolus (Lingulella) Walcott [1901, p. 688].

Obolus Matthew [1889, p. 306; 1890, p. 151]. ; Obolus (Botsfordia) Matthew [1902ce, p. 95].

602 CAMBRIAN BRACHIOPODA.

Matthew [1895a, Pl. III] has given diagrammatic illustrations and elaborate descriptions
of a number of ‘‘embryonic” characters of Botsfordia pulchra. Prof. W. A. Parks, of the
University of Toronto, sent me (in July, 1906) all the material im the Matthew collection
representing this genus and species, but I was unable to recognize the originals from which
Matthew’s drawings were made. It does not seem probable that his figures 2a, 2b, and 2¢
represent a young shell of this genus, as it is represented with a high false area similar
to that of some species of Acrothele; the same is true of figure 2g. Of the other figures, 1k,
2k, and 2i appear to be the posterior portions of adult shells from which the anterior portions
have been broken away.

There are two slabs of rock in the Matthew collection upon which there are a number
of distorted and poorly preserved interiors of the valves, some of which may have been used
in constructing restorations of the interior characters.

Matthew [1891, p. 148] regarded Botsfordia as a subgenus of Obolus, as he did not dis-
cover that the ventral valve was perforated with a pedicle opening and that the dorsal valve
was much like that of Acrothele. Redlich [1899, pp. 5-6] proposed the genus Mobergia for a
generically similar species, therefore his name becomes a synonym of Botsfordia. Redlich
[1899, p. 6] compares Mobergia with Obolella, an observation that was based on keen appre-
ciation of the cleft or pedicle groove and the arrangement of the muscle scars in the ventral
valve; the dorsal valve he compared with that of Acrothele. He said [1899, p. 6]: “‘The agree-
ment goes so far that we may consider Obolella crassa [Walcott, 1886b, p. 114] and Acrothele
granulata [Linnarsson, 1876, p. 24] as the extreme forms of Mobergia.”” The difference between
the ventral valves of Obolella crassa (Hall) and Botsfordia is that in the latter the pedicle groove
‘and area have disappeared and a narrow listrium takes the place of the area, the pedicle open-
ing passing through the shell, while in Obolella the pedicle opening is above a clearly defined
area. The dorsal valve of Botsfordia is more like that of Acrothele. The young shells of
Obolella may have been provided with a pedicle opening in the young stages of growth, much
like that in the adult stages of Botsfordia. Botsfordia appears to be a primitive form of Acro-
tretide to the extent that the false area of the ventral valve is only a thin band between the
pedicle opening and the posterior margin, whereas in Acrotreta there is a well-developed false
area. Botsfordia appears to represent the first, or, at least, an early stage between the open
pedicle furrow of Obolus and the inclosed pedicle tube of Acrothele and Acrotreta. Botsfordia
differs from Acrothele by the form of its visceral area and position of the main vascular sinuses
in the ventral valve, also the position of the pedicle opening.

The cancellated surface of Botsfordia pulchra (Matthew) is similar to that of Micromitra
(Iphidella) pannula (White) (compare Pl. LXII, figs. 5, 5a-c, with Pl. IV, figs. 1s, 1t). The
forms of surface in B. granulata (Redlich) and B. cxlata (Hall) are often found in species of
Obolus (Westonia) and Lingulella (Lingulepis) (Pls. XLIV, XLVII). The surface of Acrothele
(Redlichella) granulata (Linnarsson) (Pl. LV1) is similar to that of Botsfordia granulata (Redlich)
(Pl. LVII). In Schizopholis rugosa Waagen the false cardinal area is more developed than in
Botsfordia, and the apex is elevated. Schizopholis appears to be a form intermediate between
Botsfordia and Acrotreta. At present the species of Botsfordia known to me are B. pulchra
(Matthew), B. cxlata (Hall), B. granulata (Redlich), and B.? barrandei Walcott.

BotsForpDIA ? BARRANDEI Walcott.

Plate LVII, figures 7, 7a-b.

Brachiopode nouv. gen. DE VERNEUT and BARRANDE, 1860, Bull. Soc. géol. France for 1859-1860, 2d ser., vol. 17,
pp. 536-537, Pl. VIII, figs.5, 5a-e. (Described and discussed in French as a new species. Figs. 5, 5a-b are
copied in this monograph, Pl. LVII, figs. 7, 7a-b, respectively.)

Acrothele Pomprcks (in part), 1896, Jahrb. K.-k. geol. Reichsanstalt for 1895, Bd. 45, Hft. 3, p. 603. (Discussed in
German, changing generic reference; see p. 603 for translation.)

Botsfordia ? barrandei Waxucort, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, pp. 77-78. (Discussion in the preced-
ing reference translated and species described and discussed as on p. 603 as a new species.)

OBOLELLID. 603

Of this species Pompeckj [1896b, p. 603] writes:

From Barrande’s description and figure it is not quite easy to interpret this species. I have before me several
specimens of a brachiopod from Coulouma, in the Department of Hérault, which Miquel [1893, p. 9] mentioned as
“la Discina.”’ I regard this south French form as belonging to the genus Acrothele, and believe that it is probably
identical with the species mentioned by de Verneuil, Barrande, and Barrois as occurring in Spain.

Having before me the specimens which Miquel collected, and which I have named Acrothele
bergeroni (Pl. LVIII), I do not think they can be considered the same as the form described
by de Verneuil and Barrande. (Compare Pl. LVII, figs. 7, 7a—b with Pl. LVIILI, figs. 6, 6a—-c.)

From Barrande’s description and illustration the following note is written: The shell is
about as wide as long, suboval, with pointed beaks; valves moderately convex, with the ventral
a little more so than the dorsal. There is a small area on each valve, but no trace of a
triangular false deltidium. Beak of ventral valve with a minute pedicle opening. Surface
with fine, distinct, concentric striz. Substance of shell calcareous.

A shell 13 mm. in length has the same width, and the thickness of the two valves united
is 5 mm.

Barrande thought that a new genus was indicated, but in the absence of interior characters
decided not to name the genus or species. The perforate ventral valve and area suggested
Siphonotreta to him, but the calcareous shell was opposed to it.

I have referred the shell to the genus Botsfordia provisionally and named it after Barrande,
whose memory all paleontologists take pleasure in recalling.

The reference to Botsfordia is made on account of: (a) the subacuminate ventral valve
with minute pedicle opening above a false cardinal area unmarked by a false deltidium; (b)
the convex ventral and dorsal valve; (c) the tendency of Botsfordia pulchra Matthew to have
the substance of its rather thick shell replaced by calcareous matter.

I have attempted to secure specimens of this shell, but unsuccessfully. Until further
information can be secured the present reference will serve to indicate the probable relation-
ship of the species.

FoRMATION AND LOCALITY.—Middle Cambrian: (350 [de Verneuil and Barrande, 1860, p. 538]) Red limestone
of the Paradoxides zone, near Adrados, north of Sabero and Bofiar, Cantabrian Mountains, Province of Leon, north-

western Spain.
BoTsFORDIA CHLATA (Hall).

Plate LIX, figures 1, la—q, 3, 3a-b.

Orbicula cxlata Hatt, 1847, Nat. Hist. New York, Paleontology, vol. 1, p. 290, Pl. LXXIX, figs. 9a-c. (Described
and discussed as a new species.)

Obolella (Orbicula) celata (Hall), Forp, 1871, Am. Jour. Sci., 3d ser., vol. 2, p.33. (Merely changes generic reference.)

Obolella cxlata (Hall), Bruines, 1872, Canadian Naturalist, 2d ser., vol. 6, No. 2, p. 218. (Merely changes generic
reference.)

Tnngulella cxlata (Hall), Forp, 1878, Am. Jour. Sci., 3d ser., vol. 15, pp. 127-128. (Described and discussed.)

Inngulella celata (Hall), Watcort, 1886, Bull. U. S. Geol. Survey No. 30, p. 95, Pl. VII, figs. 1, la-d. (Copies the
first paragraph of Hall, 1847, p. 290, copies Ford, 1878, pp. 127-128, and discusses species. The specimens
represented by figs. lb and 1d are redrawn in this monograph, Pl. LIX, figs. 1c and lo, respectively.)

~ Lnngulella celata (Hall), Waxcorr, 1887, Am. Jour. Sci., 3d ser., vol. 34, p. 199, Pl. I, fig. 16, opposite p. 240. (The
description of the plate is on p. 199.)

Inngulella cxlata (Hall), Waxcorr, 1891, Tenth Ann. Rept. U. S. Geol. Survey, p. 607, Pl. LXVII, figs. 1, la-e.
(Localities mentioned. Figs. 1, la-d are copied from Walcott, 1886b, Pl. VII, figs. 1, la-d, respectively. Fig.
le is copied from Walcott, 1887, Pl. I, fig. 16.)

Lnnguleila celata (Hall), Hatt and Crarxe, 1892, Eleventh Ann. Rept. State Geologist New York for 1891, Pl. III,
figs. 14. (No text reference.)

Lingulella celata (Hall), Harn and Crarxe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, pp. 57 and 58,
Pl. II, figs. 1-4. (Mentioned in the text. Figs. 1-4 are copied from figs. 1-4 of the preceding reference.)

Lingulella (?) celata (Hall), MarrHew, 1895, Trans. New York Acad. Sci. for 1894-95, vol. 14, p. 126. (Specimens
from a new locality characterized and discussed.)

Obolus (Lingulella) bicensis Watcort, 1901, Proc. U. S. Nat. Mus., vol. 23, p. 688. (Described and discussed as a
new species. )

General form elongate ovate and varying from broad oval to oval acuminate. Ventral
valve moderately convex with the longitudinal line nearly flat from a short distance in front of

604 CAMBRIAN BRACHIOPODA.

the apex nearly to the front margin in old shells; in young shells it rises with a gentle slope from
the front margin to the umbo; the posterior margin, including some distance along the cardinal
slopes, rises and arches gently above the plane of the edges of the front and sides of the valve,
which brings the apex or beak close to the posterior margim (Pl. LIX, fig. 1b); pedicle opening
small and at the point of the apex or beak.

Dorsal valve more broadly ovate in outline than the ventral, moderately convex, and rather
strongly arched toward the beak, which is marginal; the arching of the posterior portion of the
valve causes it to fit closely into the upward arching posterior margin of the ventral valve; a
shallow median sinus of varying streneth and width “setenv from the mie toward the front
margin, where it usually disappears.

Surface highly ornamented by narrow, closely arranged, concentric, elevated, irregular, and
often inosculating lines, on which small round pustules are lined in such a manner as to give a
beaded effect to the surface. The width of the ridges and size of the pustules vary on shells
from the same localities and from different localities. Often the shells have been worn by attri-
tion so as to be almost smooth, the coarser striw and lines of growth alone remaining; in addi-
tion some shells have more or less numerous, rounded, depressed, radiating ridges, which may
be quite regular (Pl. LIX, fig. 1h) or very irregular and discontinuous (Pl. LIX, fig. 1c); some
shells are without traces of the radiating ridges and others have only the faint outlines of them.
The inner layers are usually shiny and marked by concentric lines and striz, and numerous fine
radiating strie.

Shell substance corneous; shell maine thin when young, increasing to a rather strong shell
in large specimens; it is built up of a rather thin outer laser and several inner layers or lamelle.
The largest ventral valve has a length of 10 mm., width of 8 mm., toward the anterior margin;
as this shell has been broken near the beak and also at the anterior margin, it probably had a
length of 12 to 13 mm.

The interior of the ventral valve shows strong main vascular sinuses, which originate near
the pedicle opening, and gradually separate as they extend forward into the valve; beyond the
center they curve slightly inward and terminate about the anterior fifth of the length of the
valve. A small visceral area extends a short distance forward between the main vascular
sinuses; it has a narrow depressed space across the front (Pl. LIX, fig. 1g) that indicates the
position of the central, outside lateral, and middle lateral scars; the furrow that extends from
near the center of the visceral area to the pedicle opening near the posterior margin is clearly
indicated on figure le; as the pedicle opening was at the extreme end and with only a very
narrow listrium between it and the posterior margin, the cast of it, or any trace of it, is very
difficult to find; this is rendered doubly so by the thin posterior portion of the shell breaking off
both before being embedded in the sediment and when being worked out of the rock. There
-may have been a narrow area, but it has not been seen, and nothing definite is known of the
muscle scars.

The interior of the dorsal valve shows a short narrow area, from which a rather broad, low,
median ridge extends forward beyond the center of the valve; a narrow septum is indicated
along the posterior portion of the ridge; strong main vascular sinuses originate beside the
median ridge at the back and diverge gradually as they extend into the valve; the position of
the central and lateral muscle scars appears to have been the same as in Obolus (Pl. LIX, fig. 1]),
but they have not been clearly distinguished except one central scar (h); the cardinal muscle
scars are large and situated outside of the main vascular sinuses about their own length in
advance of the area.

Observations —This species, like Botsfordia granulata (Redlich), is characterized by having
the pedicle aperture close to the posterior margin; it also has the same Obolus-like arrangement
of the visceral area, vascular sinuses, and muscle scars in the ventral valve; it differs in outline,
surface, and interior markings from B. granulata.

When studying the genus Lingulella in 1898 I left Lingulella czlata (Hall) out of the list of
species of Lingulella [Walcott, 1898b, p. 393], as I was satisfied that it did not belong there, but

i it

OBOLELLIDA. 605

it was not until the study of Botsfordia Matthew was taken up that a satisfactory generic
reference was established.

The shell appears to have been easily broken, as it is very difficult to obtain good specimens,
especially of the ventral valve. It was 10 years or more after I began collecting it before a
ventral valve was found showing the pedicle opening. In 1901 I described a young shell of this
species as Obolus (Lingulella) bicensis [Walcott, 1901, p. 688]. By comparison with other small
shells from the type locality at Troy, New York, I am satisfied that the Bic specimen is a young
shell of B. celata.

Botsfordia cxlata is widely distributed in the Lower Cambrian rocks of the St. Lawrence
River, Lake Champlain, and Hudson River valleys, and it is one of the oldest of the Cambrian
brachiopods of the Atlantic province of eastern North America.

At Troy, and in Washington County, New York, it is associated with the trilobites Eilipto-
cephala asaphoides Emmons and Conocoryphe trilineata (Emmons) of the Lower Cambrian fauna,
and in the Georgia, Vermont, section it is 700 feet lower than Olenellus thompsoni (Hall).

FORMATION AND LOCALITY.—Middle Cambrian: (308e [Matthew, 1895a, p. 126]) Beds of Division Clb1 of Matthew’s
[1895a, p. 108] Protolenus zone, on Hanford Brook, St. John County, New Brunswick.

Lower Cambrian: (20) Limestone bowlders in conglomerate, on shore at east entrance to harbor at Bic; (2r)
limestone bowlders in a conglomerate in a cut on the Intercolonial Railway, 2 miles (3.2 km.) west of Bic railway
station; and (2p) limestone on south side of road a little west of Bic and half a mile (0.8 km.) west of the road leading
to the wharf; all in Rimouski County, Quebec, Canada.

(392c) At the Straits of Belleisle, Labrador.

(319j) Sandstone 50 feet (15 m.) above the base of the section west of Parker’s quarry and about a mile (1.6 km.)
from the shore of Lake Champlain, in the township of Georgia, Franklin County, Vermont.

(29a) Limestone 1 mile (1.6 km.) below the New York Central Railroad depot at Schodack; (2b) limestone just
north of Beman Park, in the northeastern part of the city of Troy, Troy quadrangle (U. S. Geol. Survey); (367i
[Hall, 1847, p. 290]) shales near Troy; and (27) even-bedded and conglomerate limestones on the ridge in the eastern
suburb of Troy, Troy quadrangle (U. 8. Geol. Survey); allin Rensselaer County, New York.

(33) Limestone on the roadside near Rock Hill schoolhouse near North Greenwich, about 5 miles (8 km.) north-
northeast of Greenwich; (38b) limestone on M. C. Tefft’s farm, 1.5 miles (2.4 km.) east-southeast of North Greenwich,
about 5 miles (8 km.) north-northeast of Greenwich; (36b) limestone near schoolhouse No. 12, near Greenwich;
(39a) limestone 0.25 mile (0.4 km.) north of Easton Station, 3 miles (4.8 km.) south of Greenwich; and (43a) limestone
1 mile (1.6 km.) east-northeast of Salem; all in the Cambridge quadrangle (U. S. Geol. Survey), Washington County,
New York. (

(34a) Limestone 1 mile (1.6 km.) west of North Hebron, 5 miles (8 km.) south-southwest of Granville; (88)
limestone 0.25 mile (0.4 km.) north of John Hulett’s farmhouse about 3 miles (4.8 km.) west of South Granville and
4.5 miles (7.2 km.) southwest of Granville; and (38a) limestone 2 miles (3.2 km.) south of North Granville, on the
road which turns south from the road running between that village and Truthville, 4 miles (6.4 km.) west-northwest
of Granville; all in the Fort Ann quadrangle (U. 8. Geol. Survey), Washington County, New York.

(88c) Shaleat the slate quarries on the west side of the valley 1 mile (1.6 km.) north of Middle Granville, Mettawee
quadrangle (U. S. Geol. Survey); (34) limestone on roadside a little west of the bridge over Poultney River at
Low Hampton, about 5 miles (8 km.) east-northeast of Whitehall, Whitehall quadrangle (U. S. Geol. Survey);
(85) Limestones 1.5 miles (2.4 km.) north of Bald Mountain and 3.5 miles (5.6 km.) north-northwest of Greenwich,
Schuylerville quadrangle (U. S. Geol. Survey); (85a) shaly limestone on the west slope of the summit of Bald Moun-
tain, 3 miles (4.8 km.) north-northwest of Greenwich, Schuyleryille quadrangle (U. S. Geol. Survey); (338h) lime-
stone on the summit of Bald Mountain, about 2 miles (3.2 km.) northwest of Greenwich, Schuylerville quadrangle
(U.S. Geol. Survey); and (39) limestone south of the Delaware and Hudson railroad track, on the road running south-
‘southwest from Low Hampton, about 5 miles (8 km.) east-northeast of Whitehall, Whitehall quadrangle (U.S. Geol.
Survey); all in Washington County, New York.

BorsFORDIA GRANULATA (Redlich).

Plate LVII, figures 4, 4a—r.

Mobergia granulata Repuicu, 1899, Mem. Geol. Survey India, Paleontologia Indica, new ser., vol. 1, No. 1: The
Cambrian fauna of the Eastern Salt Range, pp. 5-6, Pl. I, figs. 11-18. (The description and discussion of this
new species is incorporated with that of the new genus ‘‘ Mobergia.’’)

General form subcircular, with the ventral valve very obtusely acuminate, and the dorsal
valve transversely more or less broadly oval. Ventral valve moderately convex with the

606 CAMBRIAN BRACHIOPODA.

longitudinal line nearly flat from the apex to beyond the center of the valve, where it slopes
gently to the anterior margin; on some shells the slope to the apex rises more abruptly and
there is a gentle slope from the umbo to the front margin; the posterior margin arches gently
upward from the plane of the edges of the front and sides of the valve. Apex directed back-
ward and perforated by a minute pedicle opening; it extends a little beyond the posterior
margin, and is separated from it by a narrow false area or rim of shell; on some shells an
elongate, more or less crescentiform tubercle occurs on each side of the apex, and just back of
them at the end of the depression between them the minute pedicle opening occurs, or there
may be a thickening of the shell back of the opening which results in a tubercle, as shown in
Plate LVII, figure 4d; in other shells there is simply a thickened rim of shell about the front
and sides of the apex with the pedicle opening at the posterior section of it (Pl. LVII, fig. 4c).
Dorsal valve moderately convex; it slopes rather abruptly from the umbo to the minute mar-
ginal beak and gently to the front; a minute tubercle occurs on each side of the beak of perfect
specimens (Pl. LYVII, fig. 4b).

Surface marked by concentric lines of growth and low, rounded, more or less obscure
radiating ridges that occur on the anterolateral portions, or on the central part, or all across
in front of the umbo and sides, or only as faint traces; in addition there is a system of fine undu-
lating, irregular, more or less imosculating, concentric ridges, upon which there are minute
rounded tubercles or granules that have no extended systematic arrangement; on some shells
the granulated surface extends to the front margin and on others more or less of the front
portion of the valves is marked only by concentric lines and traces of the undulating ridges;
in some places the granules are arranged in diagonal lines that cross each other obliquely, and
then the effect is a modified form of the surface of Botsfordia pulchra (Matthew).

The following are measurements of the valves:

Dimensions of valves of Botsfordia granulata (Redlich).

Length. Width.
mm. mm.
Ventraleeeeeeeeee 6.5 7.9
Wentralleeassseas 6.5 6.5 °
Dorsal. se 4 5
IDG edsocasc 4.5 5

The specimens are embedded in a fine shale and are more or less flattened by compression.

The shells are built up of a thin outer layer and several inner layers or lamelle slightly
oblique to the outer surface. The shell substance is corneous or, according to the author,
‘phosphate of lime and chitine” [Redlich, 1899, p. 6].

The interior of the ventral valve is essentially the same as that of Botsfordia pulchra
(Matthew) and B. celata (Hall); strong main vascular sinuses rise beside the median line close
to the posterior margin and gradually diverging, extend forward into the body of the valve
nearer to the median line than to the outer margins; the visceral area is about three-eighths
the length of the valve and it has a narrow median groove that terminates in a club-shaped
anterior end (Pl. LVII, fig. 4¢) that suggests the heart-shaped cavity of Obolus (Pl. VII, figs.
1, 3, and 6). . The position of the transmedian and anterior lateral muscle scars is shown close
beside the main vascular sinus; the central scars and outside and middle laterals can not be
separated but the space they occupy is indicated at c, Plate LVII, figure 4p. The cast of
the pedicle passage through the shell is shown in figure 41.

The interior of the ventral valve is much like that of Acrothele corxacea Linnarsson. (Compare
Pl. LVII, fig. 4k, with Pl. LVI, fig. 1e.) There is a median ridge with the main vascular sinuses
starting out beside it near the posterior margin and gradually separating as they extend forward
into the valve about halfway between the margins of the valve and the median ridge; the
cardinal muscle scars are small and close to the- median ridge, posterior margin, and main
vascular sinuses; the central muscle scars occur on the slope of the median ridge a little back
of the center of the valve, and the small anterior laterals close to the median line a little in
advance; in young shells the transmedian and middle and outside laterals are combined in

OBOLELLID. 607

one scar (el, Pl. LVI, fig. 4k), but in a larger shell the transmedian scars are separated back ot
the middle and outside lateral scars, which can not be distinguished as separate scars.

Observations.—Redlich [1899, p. 5] proposed the genus ‘‘Mobergia’”’ for this species. This was
well done, but Matthew [1891, p. 148] had previously described Botsfordia. Botsfordia granu-
lata (Redlich) has the same type of interior in both valves as B. pulchra (Matthew), and the
granulated surface is of the same general type except that it is more completely developed in
B. pulchra. There is a strong generic relation to Botsfordia cxlata (Hall) but the specific differ-
ences are very decided.

Doctor Holland, director of the Geological Survey of India, kindly sent me the type speci-
mens of this species, and through the courtesy of Dr. Fritz Noetling, I obtained for the United
States National Museum a fine collection of this species from the Salt Range.

FORMATION AND LocALIry.—Middle Cambrian: (15r)? Dark argillaceous shales, at Khussak, Salt Range, India.

BoTsFrorRDIA PULCHRA (Matthew).
Plate LXII, figures 5, 5a-1.

Lingulella (2) cf. Lingula favosa Linnarsson, MarrHEw, 1888, Canadian Rec. Sci., vol. 3, No.1, pp. 28-29. (Mentioned.)

Obolus pulcher MarrHew, 1889, idem, vol. 3, pp. 306-307, figs. 1-8, p. 306. (Described and discussed as a new species.)

Obolus pulcher MartuEw, 1890, Trans. Roy. Soc. Canada for 1889, Ist ser., vol. 7, sec. 4, No. 12, pp. 151-155, Pl. VIII,
figs. la-m, 2a-l. (Description given by Matthew, 1889, pp. 306-307, copied, and species described and discussed
in great detail. Figs. la-c and 2a-c are copied from figs. 3-8, respectively, of the preceding reference.)

Obolus (Botsfordia) pulcher MarrHEw, 1891, idem for 1890, vol. 8, sec. 4, No. 6, p. 148. (Mentioned.)

Obolus (Botsfordia) pulcher Martunw, 1892, idem for 1891, vol. 9, sec. 4, No. 5, pp. 62-63. (Discussed, the new sub-
generic name being proposed on page 63.)

Obolus ? pulcher Matthew, Hatt and CuarKe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, p. $1, Pl. IV x;
fig. 22. (Characterized, questioning generic reference.)

Obolus? pulcher Matthew, Haut and CrarKe, 1892, idem, p. 183. (Characterized and discussed, copying Matthew’s
notes, 1890, p. 154, on the stages of growth and development. Calls attention to resemblance of this species, in
growth stages, to Kutorgina.) :

Obolus (Botsfordia) pulchra MartHEw, 1894, Trans. Roy. Soc. Canada for 1893, 1st ser., vol. 11, sec. 4, No. 8, pp. 90-91,
Pl. XVI, figs. 3 and 3b. (Described and discussed.)

Obolus (Botsfordia) pulchra MarrHew, 1895, Trans. New York Acad. Sci. for 1894-95, vol. 14, pp. 115-121, Pl. III,
figs. la, Ik, 2a-g, 2i, and 2k (the missing figures are lacking in the reference; they have not been referred
elsewhere in this monograph). (With the exception of the note on the horizon in the first paragraph, the text is
copied from Matthew, 1890, pp. 151-155. Figs. la-i, 2a-g, and 2i are copied from Matthew, 1890, Pl. VIII, figs.
laH, 2a-g, and 2i, respectively. Figs. 1k and 2k are copied from Matthew, 1894, Pl. XVI, figs. 3b and 3,
respectively.)

Obolus (Botsfordia) pulcher Martunw, 1902, Trans. Roy. Soc. Canada for 1902, 2d ser., vol. 8, sec. 4, No. 3, p. 95, Pl.
I, figs. 7a—b. (Characterized and discussed.)

General outline subcircular; the ventral valve being obtusely acuminate and the dorsal
a little wider than long. Ventral valve gently convex, most elevated at or a little in front
of the apex; apex close to the posterior margin and pointed backward; there is a minute
pedicle aperture at the end of the apex. The posterior margin of the valve is arched upward
so as to leave only a narrow rim between the margin and the pedicle aperture. Dorsal valve
moderately convex, more arched toward the front in old shells, and in all shells it arches upward
at the posterior margin so as to fit closely against the margin of the ventral valve.

Surface marked by concentric lines of growth that form imbricating ridges at irregular
intervals. In addition there is a reticulated surface formed by the presence on the rounded
concentric ridges of small tubercles that are rounded quadrilateral in outline and that
alternate on the adjacent ridges, so that each tubercle falls opposite the space between
the two tubercles in front; this results in rows of tubercles that are apparently arranged in
oblique rows extending from the posterolateral margin of the shell on each side obliquely
forward to the margin of the shell on the opposite side; the depressions between the tubercles
unite and serve to increase the appearance of an oblique reticulate, tuberculated surface; the
tubercles are low at the back and high in front. The finely cancellated surface is usually on
the posterior half of the shell, the tubercles becoming scattered and often entirely absent over

a Specimens from the type locality were given to the United States National Museum and this number was assigned to them.

608 CAMBRIAN BRACHIOPODA.

the anterior and lateral portion of the valves. The interior layers and interior surface show
numerous fine, radiating striz, and there are also a few radiating lines on the anterior portion
of the adult shells.

The shell is built up of a thin outer layer and numerous inner layers or lamellx that are
oblique to the outer surface; the oblique layers on the front portion and sides of adult shells
terminate at the growth lines, so as to give an imbricated appearance to the surface. Shell
substance apparently corneous.

A large ventral valve has a length and breadth of 11.5 mm. A dorsal valve 10 mm. long
has a width of 12 mm. These proportions vary slightly in different shells.

The interior of the adult ventral valve is much like that of Botsfordia czlata (Hall). It
has a short visceral area between distinctly marked main vascular sinuses that originate one
on each side of the median line at the posterior margin, and gradually separate as they extend
forward into the valve; no distinct muscle scars have been seen in this valve. The interior
of the dorsal valve has a long central ridge extending well toward the front of the valve; at
about the center it shows a tendency to bifureate; the main vascular sinuses originate at the
median line near the posterior margin and arch rapidly outward on each side and then obliquely
forward into the body of the valve; the muscle scars are represented by an elongate cardinal
scar on each side near the main vascular sinus, where it curves forward into the valve; also
one central muscle scar on each side of the median ridge a little back of the center of the valve.

Under the description of the genus Botsfordia I have referred (p. 602) to the description of
the interior of this species by Matthew. I have given above all I can observe on the specimens
in the Matthew collection now at the University of Toronto, also on the specimens in the col-
‘lection of the United States National Museum.

Observations.—This species is so clearly distinct from Botsfordia celata (Hall) and B. gran-
ulata (Redlich) that comparison is unnecessary. It agrees with both of the latter species in
having the perforated apex of the ventral valve separated from the posterior margin by a
narrow rim of shell, also in having a short visceral area and strong main vascular sinuses. The
dorsal valves are of the same general type.

ForMATION AND LOCALITY.—Middle Cambrian: (2y) Sandstone about 25 feet (7.6 m.) above the Lower Cambrian,

on the southeast side of Catons Island; and (308d [ Matthew, 1894, p. 121]) sandstones of Division C1b2-4 of Matthew's
section on Oatons Island; both in Long Reach, St. John River, Kings County, New Brunswick.

Genus SCHIZOPHOLIS Waagen.
[exzttw, I divide; and ¢odic, a scale.]

Schizopholis WAAGEN, 1885, Mem. Geol. Survey India, Paleontologia Indica, 18th ser., Salt Range Fossils, vol. 1,
pt. 1, p. 752. (Described as a new genus.)

Schizopholis Waagen, OEHLERT, 1887, Manuel de conchyliologie, by Fischer, p. 1267. (Described in French, with
figures of S. rugosa.)

Schizopholis Waagen, Hat and Crarke, 1892, Eleventh Ann. Rept. State Geologist New York for 1891, p. 248. (De-
scribed.)

Schizopholis Waagen, Haut and CLarxKe, 1892, Porty-fifth Ann. Rept. New York State Museum for 1891, p. 564. (Copy
of preceding reference.)

Schizopholis Waagen, Haut and CrarKe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, p.94. (Copies original
description and discusses genus.)

Schizopholis Waagen, Watcort, 1908, Smithsonian Misc. Coll., vol. 53, No. 4, Pl. XI, and pp. 142 and 145. (Classi-
fication of genus.)

Revised generic description.—Ventral valve slightly conical with eccentric apex perforated
on the posterior side by a minute foramen. On the posterior slope beneath the apex there
is a slightly flattened false area across which the strie of growth of the shell appear. The
strie arch upward near the center and form a narrow false deltidium, very much as in the
genera Acrothele and Acrotreta. The pedicle opening occurs at the apex of the false deltidium
and penetrates the apex of the shell. Dorsal valve nearly flat, umbo slightly elevated, beak
marginal.

Surface of shell marked by fine concentric lines and strie of growth, and irregular, inter-
rupted, slightly elevated, radiating ridges which give a rugose appearance to the surface. Shell
substance caleareocorneous. Shell built up of several layers or lamelle.

OBOLELLIDZ. 609

Type.—Schizopholis rugosa Waagen.

Observations.—The generic relations of this shell, as far as can now be determined, are
with <Acrothele. With our present information it differs only in its more marked false del-
tidium.

The interior of a dorsal valve from the same bed of sandstone is tentatively referred to
this species (Pl. I, fig. 4c). The area of the valve is narrow and not clearly defined; it appears
to be merged into a small projecting platform that extends in front into a strong median ridge;
at each side of the ridge the platform-like area overhangs a little so as to form a slight hollow
beneath; the median ridge extends nearly to the front margin of the shell, very much as in
‘the dorsal valve of Acrotreta sagitialis (Salter) (PI. LXXI, fig. 3g).

My interpretation of this shell differs somewhat from that of Waagen [1885, p. 752].
This arises from his thinking that the false deltidium was an open fissure. On cleaning away
the dirt I find that there is a depressed triangular space and that the lines and striz of growth
cross the false area and the false deltidium; also that the foraminal opening is a simple cir-
cular aperture as in Acrothele.

SCHIZOPHOLIS RUGOSA Waagen.
Plate I, figure 4c; Plate LX XX], figures 1, la=c.

ly

Schizopholis rugosa WAAGEN, 1885, Mem. Geol. Survey India, Paleontologia Indica, 13th ser., Salt Range Fossils, vol.
1, pt. 1, pp. 753-754, Pl. LXXXVI, figs. 2-4. (Described and discussed as a new species. The specimens rep- :
resented by figs. 3 and 4 are redrawn in this monograph, Pl. LX X XI, figs. 1c and 1, la-b, respectively.)

Schizopholis rugosa WAAGEN, 1891, idem, vol. 4, pt. 2, Pl. II, figs. 12-14. (No text reference. With the exception of
fig. 4c, which is not copied in 1891, figs. 13, 14, and 12 are copied from figs. 24, respectively, of the preceding
reference. )

Schizopholis rugosa Waagen, Hatt and CiarKe, 1892, Eleventh Ann. Rept. State Geologist New York for 1891, p. 248,
figs. 259 and 260. (No text reference. Figs. 259 and 260 are copied from Waagen, 1885, Pl. LX X XVI, figs.
4d and 4b, respectively.)

Schizopholis rugosa Waagen, Hai and CiaRKE, 1892, Forty-fifth Ann. Rept. New York State Museum for 1891, p. 564,
figs. 259 and 260. (Copy of preceding reference.)

Schizopholis rugosa Waagen, Hatt and CrarKe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, p. 95, figs. 50
and 51. (Mentioned in discussion of genus Schizopholis. Figs. 50 and 51 are copied from Waagen, 1885,
Pl. LXXXVI, figs. 4d and 4b, respectively.)

General form ovate. Ventral valve slightly convex, greatest elevation at the apex, which
is nearly above the posterior margin; apex minute and perforated by a circular opening. The
posterior side of the shell beneath the apex is slightly flattened so as to form a false area, divided
midway by a false deltidium formed by the arching of the lines and striz of growth; an angle
is formed at the point where the lines and striz arch upward, which gives form to the slight
depression, or the false deltidium. Dorsal valve nearly flat, except near the umbo, which is
slightly elevated, apex marginal, minute.

Surface marked by numerous concentric lines and striz of growth, and irregular, inter-
rupted, slightly elevated, radiating ridges that vary in size and direction on different shells.
The shell is thin on the edges, becoming thicker toward the umbonal portions by the addition
of thin layers or lamelle. The type specimen of the ventral valve has a length and width of
6 mm.

Observations —This species is allied to Botsfordia celata (Hall). It differs in surface charac-
ters, general outline, and the presence of a false deltidium and area.

FoRMATION AND LOCALITY.—Middle Cambrian: (357¢ [Waagen, 1885, p. 754]) Lower portion of the ‘‘Neobolus

beds” of the Khussak group, in purplish-colored, fine-grained, micaceous sandstone, near the fresh-water springs in a
gorge above the salt mines at Kiura (Khewra), Salt Range, India.

Genus QUEBECIA Walcott.¢

Quebecia Waxcorr, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 320. (Mentioned as on p. 610 as a new genus.)
Quebecia Waxcort, 1908, Smithsonian Misc. Coll., vol. 53, No. 4, Pl. XI, and pp. 142and 145. (Classification of genus.)

a The synonymy for this genus does not give acomplete record of the various genera under which the species now includedin Quebecia were
formerly placed; it gives only those references in which the genus is discussed or described. To complete the record the following generic
references are listed: 5
Obolella Billings [1872a, p. 219; 1872c, p. 357}. Obolella Walcott [1886b, p. 118; 1891a, p. 611].

62667°—vot 51, pr 1—12—— 39

610 CAMBRIAN BRACHIOPODA.

The description of the species includes that of the genus, as there is only one species now
known.

Type.—Obolella circe Billings.

The generic name is derived from the city of Quebec, near which the type species occurs.

QUEBECIA CIRCE (Billings).
Plate CIV, figures 7, 7a-2.

Obolella circe Brnt1nes, 1872, Canadian Naturalist, 2d ser., vol. 6, No. 2, pp. 219-220. (Described and discussed as a
new species. )

Obolella circe BrruinGs, 1872, Am. Jour. Sci., 3d ser., vol. 3, pp. 357-3858. (Copy of preceding reference.)

Obolella circe Billings, Watcorr (in part), 1886, Bull. U. S. Geol. Survey No. 30, p. 118, Pl. X, fig. 3a (not fig. 3).
(Original description, Billings, 1872a, pp. 219-220, copied. The specimen represented by fig. 3a is redrawn in
this monograph, Pl. CIV, fig. 7e. Fig. 3 represents a specimen of Obolella chromatica.)

Obolella circe Billings, WaLcorr (in part), 1891, Tenth Ann. Rept. U. S. Geol. Survey, p. 611, Pl. LX XT, fig. 3a (not
fic. 3). (Mentioned. Fig. 3a is copied from Walcott, 1886b, Pl. X, fig. 3a. Fig. 3 represents a specimen of
Obolella chromatica.)

Billingsella circe (Billings), Waucorr, 1901, Proc. U. 8. Nat. Mus., vol. 23, p.673. (Merely changes generic reference.)

Quebecia circe (Billings), Watcott, 1905, Proc. U.S. Nat. Mus., vol. 28, pp. 320-321. (Described and discussed essen-
tially as below.)

General form broad ovate, with front and sides uniformly rounded, planoconvex. Surface
marked by fine concentric striz of growth. A ventral valve 3.5 mm. in length has a width of
4.5mm. A dorsal valve 4.5 mm. in length has the same width; a larger dorsal valve, 11 mm.
in length, has a width of 10.5 mm. Shell rather thick, and composed of calcite in its present
condition.

The ventral valve has an elevated umbo terminating in a sharp upward-pointing apex
that may be perforate; from the umbo the surface, in young shells, slopes so rapidly that the
central and outer portions of the shell are nearly flat, but in older shells moderately convex;
area short and divided midway by a relatively broad delthyrium that is nearly covered by a
convex deltidium; the inner surface is marked by fine, elevated, rather widely separated, radi-
ating strie and very fine puncte; the very broad main vascular sinuses arch forward from a
point beneath the umbo and inclose a small, slightly elevated visceral area; a strong cardinal
tubercle occurs on each side of the pseudo-area (cl, Pl. CIV, figs. 7a and 7b) which was probably
the point of attachment of the cardinal muscle, 1. e., transmedian and anterior laterals.

Dorsal valve gently convex in young shells, becoming strongly convex in old shells; no
traces of an area have been observed—if present it must have been short and very low, as the
beak is nearly at the plane of the margins of the shell; casts of the interior show that the valve
was thickened beneath the umbo by a ridge that separated what may be called the umbonal
cavity from the main cavity of the valve. On the cast of an old shell a rounded, narrow, longi-
tudinal, median ridge divides the umbonal cavity; on each side of the cavity and beyond it
there is the strongly marked path of advance of the transmedian muscle scars; in front of the
transverse ridge two strong ridges that extend toward the center of the valve occupy the position
of the main vascular trunks; in one specimen a narrow groove extends from the central muscle
scar along the inside margin of the ridge (Pl. CIV, fig. 7).

The muscle scars now known are the transmedians and centrals; the former are situated
close to the margin of the valve, and the space assigned them may also include the posterior
laterals; the central scars are well indicated in several specimens, but no trace has been found
of the anterolaterals. The cardinal tubercle (cl) cludes the space that was occupied by
the several points of attachment of the posterior muscle, i. e., transmedian, outside lateral,
and middle laterals; the cast of the tubercle is an elongate depression just inside the margin
of the shell.

Observations.—By incorrect interpretation, both Mr. Billings [1872a, p. 220] and myself
[1886b, p. 118] identified the dorsal valve of the species as the ventral, and I illustrated [1886b,
Pl. X, fig. 3] a dorsal valve of Obolella chromatica as the dorsal valve of “O. circe.” When

SIPHONOTRETIDA. 611

studying some material representing the species in the collections of the United States National
Museum I noticed the edge of a shell that, on working it free from the matrix, proved to be
a ventral valve; two dorsal valves occur on the same bit of rock. Subsequently Dr. J. F.
Whiteaves sent me a tablet from the collections of the Geological Survey of Canada, on which
six specimens were labeled ‘‘Obolella circe.” No.1 is a cast of the interior of the dorsal valve
of Obolella crassa (Hall), and No. 2 the exterior of the same species. Nos. 3 and 6 are ventral
valves of Quebecia circe, and Nos. 4 and 5 dorsal valves.

With the ventral valve identified, it appeared that the shell was not an Obolella, but the
type of an undescribed genus in which the ventral valve is elevated at the apex, with strong
cardinal tubercles for the attachment of the posterior muscle scars, very much as in Acro-
treta, and Quebecia was proposed. The cardinal tubercles and the presence of what appears to
be the base of the cast of a foraminal tube suggest that the ventral valve was perforate.
Obolella, Quebecia, and Yorkia are all strong, calcareous, perforate shells of the older Cambrian
fauna, and are evidently closely related.

FoRMATION AND LOCALITY.—Lower Cambrian: (3191 [Billings, 1872a, p. 220|)% Limestone bowlders in conglom-

erate at Trois Pistoles, on St. Lawrence River, below Quebec, Canada.
(892c [Billings, 1872a, p. 218]) at the Straits of Belleisle, Labrador.

Family SIPHONOTRETIDZ Kutorga.

Genus YORKIA Walcott.

Yorkia Waxcort, 1897, Proc. U. S. Nat. Mus., vol. 19, p. 714. (Described and discussed as below as a new genus.)
Yorkia Waxcorr, 1908, Smithsonian Mise. Coll., vol. 53, No.4, Pl. XI, and pp. 142 and 146. (Classification of genus.)

Shell inarticulate, subcircular to suborbicular in outline. Apex of ventral valve perforate,
marginal, with a false area and a pseudodeltidium. The cast of the interior of the valve shows
a foramen which penetrated obliquely upward and backward through the thick umbonal por-
tion of the shell. Two narrow furrows converge from the side of the pedicle opening toward
the longitudinal mesial depression and then diverge toward the anterolateral portions of the
shell.

The dorsal valve has a well-defined area and an obscure pseudodeltidium. The interior
of this valve has a pair of broad, diverging, shear-shaped furrows passing directly forward
from the beak for a short distance and then diverging to the outer margin, but not sufficiently
to affect the outward curve of the mner margin.

Shell substance probably calcareous. External surface marked with more or less promi-
nent concentric striz and lines of growth.

Type.— Y orkia wannert Walcott.

Observations—The area and pseudodeltidium of the ventral valve resemble the same
parts in Trematobolus insignis Matthew, but the pedicle opening is quite different, and gen-
-erally the interior of the dorsal valves also serves to distinguish the forms. To Discinopsis
Matthew there is a resemblance in the markings of the interior of the dorsal valve. Disci-
nopsis, however, is founded upon a small, apparently corneous shell, which, so far as known,
has no area or pseudodeltidium, and it is closely related to Acrothele. Yorkia differs from
Acrothele in its pronounced area, substance of shell, and place of origin of vascular trunks.
I do not know of any other genus of the Siphonotretid# with which it can be compared.

The generic name is derived from York, Pennsylvania, near which the type species occurs.

YORKIA? MIQUELI 0. sp.
=; Plate LX XXII, figure 4.

This species is represented by specimens of the ventral valve, that are compressed in
arenaceous shale, and distorted dorsal valves. The ventral valve is small, 2 to 4 mm. in
diameter; subcircular to transversely oval in outline, with the highest point at the apex,

a Specimens from this locality are included in the collections of the United States National Museum.

612 CAMBRIAN BRACHIOPODA.

which is truncated by a circular opening; posterior slope unknown. Surface, as preserved
in the arenaceous shale, marked by concentric striz and lines of growth and obscure, very
fine, radiating strie. The substance of the shell appears to be cormedss and to make up sev-
eral very thin lamelle that combined make a thin shell.

The generic reference is doubtful, owing to the. corneous, shiny character of the shell.
This species and Yorkia? washingtonensis Walcott may belong to a new genus or a subgenus
of Yorkia.

The specific name is given in honor of Mr. J. Miquel, of Barroubio, France.

FoRMATION AND LOCALITY.—Passage beds between Cambrian and Ordovician, or Lower Ordovician: (342a)
Barren quartzitic beds, Coulouma, Department of Hérault, France.

YorxKIA? ORIENTALIS Walcott.
Plate LX XXII, figures 3, 3a.

Yorkia? orientalis Watcorr, 1906, Proc. U. S. Nat. Mus., vol. 30, pp. 569-570. (Described and discussed as below
as a Dew species.)

This species is represented by a single small ventral valve, which has the external char-
acteristics of Yorkia wanneri Walcott, of the Lower Cambrian. The outline of the valve is
transversely and broadly oval in outline exclusive of the apex rising above the posterior mar-
gin; the apex gives a subtriangular outline to the valve when looking down upon it; the apex
is moderately elevated and projects over the posterior margin; it is perforated by a rather
large aperture just above a small false area.

The surface of the valve is marked by low, rather broad, concentric undulations, a few
fine, concentric strie, and a very fine reticulate ornamentation formed by the crossing of
oblique, elevated, curved lines, which form slightly elongate diamond-shaped pits between
them. Shell substance apparently calcareous. Width of ventral pele 2.5 mm.; length, 2
mm. at aperture, 2.25 at apex; elevation, 0.5 to 0.75 mm.

Observations—As far as may be determined by the exterior of ine valve, this species is
properly referred to Yorkia. The generic reference, however, will remain in doubt until
information is available as to the characters of the interior of the valve.

ForMATION AND LOCALITY.—Middle Cambrian: (C71) Massive clifi-lorming limestone in the central portion of

Kichou formation [Willis and Blackwelder, 1907, pp. 139 and 145 (2d list of fossils)], 4 miles (6.4 km.) south-southwest
of Tungyu, Shansi, China.

YORKIA WANNERI Walcott.
Plate LX XXII, figures 1, la-i.

Yorkia wanneri Watcort, 1897, Proc. U. S. Nat. Mus., vol. 19, p. 715, Pl. LX, figs. 1, la-e. (Described and dis-
cussed as below as a new species. The specimens represented by figs. 1, la~e are redrawn in this monograph,

Pl. LXXXII, figs. 1a, le, 1g, lh, and 1i, respectively; figs. 1b and 1c of the original reference (PI. LX) being

both drawn from the specimen represented in fig. 1g of Pl. LX XXII of this monograph.)

Shell subcirecular to suborbicular in outline, moderately convex, with the apices of the
valves marginal. Ventral valve highest at the beak, which is truncated by a circular foraminal
opening ; candi slope angular and slightly incurved, so as to form a narrow false area on
each side of the slightly convex, rather broad pseudodeltidium. Numerous casts show the
pseudodeltidium, false area, and a large filling or cast of the foramen which extended obliquely
backward through the thickened umbonal portion of the shell to the apex. On a cast of the
interior of the valve there are two elongated muscular or vascular (probably the latter) im-
pressions that extend from the anterolateral base of the foraminal opening inward nearly to
the median line, and then diagonally outward toward the anterior lateral margin of the shell.
There is also a slight median longitudinal ridge that corresponds to a depression in the inte-
rior of the shell (Pl. LX XXII, figs. 1b and 1c). In other casts striz or lines only are shown

7

SIPHONOTRETID. 613

radiating outward from the base of the foramen. Fine transverse striz cross the narrow area
and then imcurve and cross the pseudodeltidium.

The dorsal valve has a well-defined area, with an obscure pseudodeltidium parting it mid-
way. The cast of the interior of the valve shows two broad, shear-shaped diverging ridges
that extend from near the apex to the center of the shell. Numerous vascular markings extend
outward from the ridges. These ridges may indicate the muscular scars or merely the main
trunks of the vascular depressions. The surface of the area is marked by fine transverse strix
that abruptly incurve toward the front of the area, so as to follow along its anterior margin
to the pseudodeltidium.

The surfaces of both valves, as shown in the casts, are smooth, except where marked by
concentric lines of growth.

Shell substance unknown, but probably calcareous. It is dissolved away in all the speci-
mens in the collection, only the impression of the shell remaining in the decomposed arenaceous
limestone.

This species occurs in abundance, associated with Nisusia festinata, Hyolithes americanus,
and fragments of Olenellus.

The specific name was given in honor of Mr. Atreus Wanner.

ForMATION AND LOcALIty.—Lower Cambrian: (49) Sandstone on Codorus Creek 0.125 mile (0.2 km.) below Meyer’s
mill, near Emigsville; and (49a) sandstone on the Liverpool road, south of the schoolhouse, 3 miles (4.8 km.) northwest
of York; both in York County, Pennsylvania.

Specimens that are somewhat doubtfully referred to this species occur at the following
localities:

Lower Cambrian: (20) Limestone bowlders in conglomerate, on shore at east entrance to harbor at Bic, Rimouski

County, Quebec.
(7) Shaly beds about 1,000 feet (305 m.) above the quartzitic beds, Silver Canyon, White Mountain Range, Inyo

County, California.
YORKIA? WASHINGTONENSIS Walcott.
=f Plate LX XXII, figures 2, 2a.

Yorkia? washingtonensis Watcort, 1897, Proc. U. 8. Nat. Mus., vol. 19, pp. 715-716, Pl. LX, fic.3. (Described and
discussed as below as a new species. The specimen represented by fig. 3 is redrawn in this monograph, Pl.
LXXXII, fig. 2.)

Ventral valve longitudinally ovate, depressed, convex. Area and pseudodeltidium invisi-
ble, but, from the character of the foramen and its resemblance to the foramen of Y. wanneri,
it is probable that the area was somewhat similar to the area of that species. The cast of
the interior of the ventral valve shows a rather long, large foramen, in advance of which two
ridges (vascular trunks) diverge somewhat as in the ventral valve of Y. wanneri Walcott
(p. 612). There is also present a short longitudinal depression in the cast, which indicates
a corresponding mesial ridge just in advance of the foramen. The surface of the interior of the
shell is marked by fine concentric lines and very fine interior ridges. Shell substance appar-
ently corneous. .

This species is founded upon two partial casts of the ventral valve, preserved in com-
pact gray limestone. The shell appears to be very thin over the outer portions and thick
over the umbonal region.

The generic reference is somewhat doubtful. Obolella is suggested by the cast of the
pedicle tube, also Trematobolus. The pedicle tube and form of the vascular trunks suggest
Yorkia, while the shell substance is more like that of Botsfordia.

The specific name is derived from Washington County, New York.

FORMATION AND LOcCALITY.—Lower Cambrian: (37b) Limestone 0.25 mile (0.4 km.) east of Salem, Cambridge
quadrangle (U. S. Geol. Survey), Washington County; (838n) western belt of conglomeratic limestone, Rensselaer
County; and (88a) limestone 2 miles (3.2 km.) south of North Granville, on the road which turns south from the road
running between that village and Truthville, 4 miles (6.4 km.) west-northwest of Granville, Fort Ann quadrangle
(U.S. Geol. Survey), Washington County; all in New York.

614 CAMBRIAN BRACHIOPODA.

Genus DEARBORNIA Walcott.

Dearbornia Waucorr, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, p.78. (Mentioned as below as a new genus.)
Dearbornia Waucort, 1908, idem, vol. 53, No. 4, Pl. XI, and pp. 142 and 146. (Classification of genus.)

This genus is based on one species, which is well represented by fourteen specimens. The
generic description is incorporated with the description of the type species.

Type.—Dearbornia clarki Walcott.

The generic name is taken from Mount Dearborn, named after Gen. Henry Dearborn,
near which the type specimens were collected.

DEARBORNIA CLARKI Walcott. |

Plate LX XXII, figures 7, 7a-d.

Dearbornia clarki Waucort, 1908, Smithsonian Misc. Coll., vol. 538, No. 3, pp. 78-80, Pl. VIII, fig. 7. (Described and
discussed as below as a new species. Fig. 7 is copied in this monograph, Pl. LX XXII, fig. 7.)

}

Shell subequivalve, subcircular in outline, slightly convex. Ventral valve most elevated
at the pedicle aperture, which is circular, rather large, and situated from one-fifth to one-sixth
the length of the valve from the posterior margin; the slope back of the foramen is gently
rounded and without a trace of false area or pedicle groove; the position of the beak is not clearly
defined, as the margin isrounded and the uniform slope of the outer surface is unbroken. Dorsal
valve uniformly and slightly convex; the position of the beak is indicated by a slight projection
of the outline of the valve.

Surface marked by fine concentric lines. The substance of the shell is calcareous in an
oolitic limestone in which semiphosphatic shells of Obolus are preserved. The shell is thick and
apparently formed of one layer, but this is probably, as in the case of the shells of Obolella
crassa (Hall), a condition of preservation, the original layers or lamellz having been replaced or
else cemented together. The average size of the valves is from 3 to 5 mm.

The interior of the ventral valve does not show a true area; there is a space between the
margin and the end of the median furrow, into which the foramen opens. The median furrow
is rather broad and deepest at the foramen; it extends forward beyond the center of the valve;
the furrow into which the foramen opens is broadest at the posterior end, and runs out to a
point a little in advance of the opening; from each side of the furrow and opposite the opening a
furrow extends obliquely outward and then forward subparallel to the median furrow. Two
large, oval muscle scars occur in the space between the outer furrow and the posterolateral
margin of the shell; these scars correspond in position to the transmedian and anterior lateral
muscle scars of Obolus and Trematobolus. Nothing is clearly shown of the position of the main
vascular canals unless the grooves outside of the median depression indicate their position, or
it may be that they were on the narrow ridges outside of the side furrows and inside of the
lateral muscle scars.

The interior of the dorsal valve shows a rudimentary area much like that of Rustella edsont
Walcott (PI. I, fig. 1c); the area is a smooth space, with a slightly defined central depression
from which a narrow, low median septum extends forward to about the center of the valve; a
narrow ridge extends forward from the posterior central depression on each side at about the
inner third of the distance between the median septum and the outer margin; these ridges
probably marked the position of the main vascular sinuses. The central muscle scars (h)
occur in the shallow depression on each side of the median septum, a little back of the trans-
verse center of the valve, and the transmedian scars and outside laterals are just outside of
the narrow ridges on each side of the valve; these scars, like those m the ventral valve, are
large for so small a shell.

Observations.—Dearbornia clarki is one of the simple or rudimentary forms of Siphono-
tretide. It differs from Siphonotreta in the absence of an area and a siphonal or pedicle tube,
in having the pedicle opening on the umbo in advance of the beak, and in its calcareous shell.
The circular pedicle aperture without an exterior furrow, the absence of a well-defined area on
the ventral valve, and its calcareous shell distinguish it from Trematobolus and Schizambon.
The form and position of the pedicle opening suggest Discinopsis, but the interiors of the valves

1

SIPHONOTRETID. 615

are very dissimilar in the two genera. It may be that with the discovery of good exteriors of
the ventral valve of Trematobolus excelsis Walcott that species will be found to have a circular
pedicle opening of the same character as that of Dearbornia clarki, but from the similarity of
the cast of the imterior of the ventral valve of the former species to that of Trematobolus kem-
panum (Matthew) it is referred to Trematobolus.
The specific name is given in recognition of Dr. William B. Clark’s work on the paleontology
of Maryland.
FoRMATION AND LOCALITY.—Middle Cambrian: (9k) Limestone forming 1c of the Dearborn River section [Wal-

cott, 1908f, p. 201], on North Fork of Dearborn River, in the eastern part of the Lewis and Clark National Forest,
Lewis and Clark County, Montana.

Genus TREMATOBOLUS Matthew.a
[cenua, perforation; and Obolus.]
Trematobolus MattHEw, 1893, Canadian Rec. Sci., vol. 5, pp. 276-279. (The species Trematobolus insignis is described
and discussed, the description of the new genus and notes on its position being incorporated.)
Trematobolus Matthew, Hatt and CiarKe, 1892, Hleventh Ann. Rept. State Geologist New York for 1891, p. 252.
Described.
Pe as ee Hatt and Crarke, 1892,> Forty-fifth Ann. Rept. New York State Museum for 1891, p. 568.

(Copy of preceding reference.)

Trematobolus Marramw, 1894, Trans. Roy. Soc. Canada for 1893, Ist ser., vol. 11, sec. 4, No. 8, pp. 88-90. (Except

for the last paragraph, this is a copy of Matthew, 1893a, pp. 276-279.)
aaa ola. 1895, Trans. New York Acad. Sci. for 1894-95, vol. 14, pp. 122-125. (A copy of the preceding

reference.

Protosiphon MarrHEw, 1897, Geol. Mag., new ser., dec. 4, vol. 4, pp. 68-69. (Described and discussed as a new genus.)

Protosiphon Matrunw, 1898, Trans. Roy. Soc. Canada for 1898, 2d ser., vol. 4, sec. 4, No. 2, pp. 129-130. (Described
and discussed.)

Trematobolus Matthew, Waucorr, 1908, Smithsonian Misc. Coll., vol. 53, No. 4, Pl. XI, and pp. 142 and 146. (Classi-
fication of genus.)

Shell rather thick, subcireular or oval in outline, biconvex; valves inarticulate. Ventral
valve with the beak at or very near the posterior margin. Pedicle opening in front of the
beak, at the anterior end of an elongate external groove that begins at the beak and broadens
out to the foramen, which is a simple opening through the thick shell; the elongate depression
and the opening through the shell are marked by strong lines of shell growth. Dorsal valve
usually more convex than the ventral; beak marginal.

Shell built up of several layers or lamelle that appear to be calcareocorneous, as the
result of the replacement in part of the original shell. Cardinal area of the ventral valve short;
it rises from the plane of the margins of the valves at angles varying from 25° to 85°; it
varies in width and outline with the configuration of the valve. Area of dorsal valve nearly
on the plane of the margins of the valves or rising at angles as high as 15°. The area
of the ventral valve is divided midway by a distinct furrow that varies greatly mm width
and depth; in some specimens it is little more than a faintly impressed line (Pl. LX XXIII,
fig. 1g) and in others it is an elongate triangular furrow (Pl. LX XXIII, fig. 11); in some speci-
mens the inner angle of the area next to the median furrow projects forward so as to form a
toothlike knob, which, in the cast, is shown by a deep, sharp indentation on each side of the
cast of the median furrow. These knobs are the teeth described by Matthew [1893a, p. 277].
They correspond to similar projections in Obolella (Pl. LV, figs. le, 1f, 3c), and Bicia gemma
(Pl. L, figs. li-k). The area of the dorsal valve is narrow and divided by a central, slightly
depressed triangular space; the areas of both valves are crossed by strong, sharp, transverse
striez of growth that pass uninterruptedly across the median furrow.

There are no traces of the foraminal groove on the interior of the ventral valve; it is
entirely within the substance of the shell and did not form a ridge on the inside of the shell.
A cast of the groove is shown in Plate LX XXIII, figure 1o.

The splanchnoceele of the ventral valve is back of the center, while in the dorsal valve
it extends to the center; a median depression extends nearly to the front of the splanchnoceele
of the ventral valve into which the foramen opens at about the posterior two-fifths of the

a The synonymy for this genus includes only those references in which the genus is discussed or described. To complete the record Obolus
Matthew [1895a, p. 121; 1902c, p. 96] should be listed.

> This date (1892) is taken from the title-page and is used throughout this monograph, but the work is clearly antedated, the correct date being
1893 or 1894.

616 CAMBRIAN BRACHIOPODA.

length of the depression; traces of a median septum occur in the dorsal valve. The grooves
of the main vascular canals begin in each valve at the front margin of the area and arch out-
ward and forward, and then, after passing the center of the valve, curve gently inward, termi-
nating’ toward the front of the valve; only traces of the secondary radial canals have been
observed. The course of the parietal scar in each valve is probably much like that of Obolus.
The muscle scars, as far as known, are essentially the same as those of Obolus. In the ventral
valve the transmedian (i) and anterior laterals (j) occur just outside of the line of the main
vascular canals. The position of the outside (1) and middle (k) laterals and central (h) scars
is within the areas (c) on each side of the anterior termination of the median depression. In
the dorsal valve the centrals (h) and anterior laterals (j) are clearly defined, and the position
of the transmedian () and outside laterals (1) is indicated. The umbonal scars are small and
are situated in the ventral valve close to the sides of the anterior end of the furrow in the
area; they have not been recognized in the dorsal valve. Pedicle muscle scars unknown.

Type.—Trematobolus insignis Matthew.

Observations—The above description is quite unlike that given of this genus by Matthew
[1893a, p. 276]. It is drawn up from specimens of Trematobolus insignis, lent to me, first by
Dr. Matthew, and later by Prof. W. A. Parks of the University of Toronto, and a fine series of
specimens collected by Mr.S. Ward Loper for the United States National Museum at the type
locality. J find that the specimen illustrated and described by Matthew [1893a, p. 276, fig. 1a]
as the interior of the ventral valve is a natural cast of the exterror of a ventral valve, presery-
ing the cast of the area and the elongate depression formed by the advance of the pedicle
opening, and that his dorsal valve (1b) is the cast of the interior of a ventral valve. The type
specimen of Matthew’s ventral valve [1893a, p. 276, fig. 1a] is illustrated by Plate LX XXIV,
figure 5b, and the cast of it by figure 5c. The muscle scars illustrated by Matthew are slight
irregularities that existed on the outer surface of the shell, along the stronger lines of growth.
The type specimen of Matthew’s dorsal valve [1893a, p. 276, fig. 1b] is illustrated by Plate
LXXXIV, figure 5; it should be compared with the casts of the interior of the ventral valve
of Trematobolus kempanum (Matthew) as shown by Plate LX XXIII, figures le and 1d.

The generic relations of Trematobolus insignis Matthew and T. kempanum, the type of
the genus Protosiphon Matthew [1897a, p. 68], may be seen by comparimg Plate LX XXIII,
figure 1, with Plate LX XXIV, figure 5c, and Plate LX XXIV, figures 5 and 5a, with Plate
LXXXIII, figures 1d and 1j. They appear to be generically the same. The specimens of
Trematobolus insignis Matthew and Protosiphon pristinus (see Trematobolus pristinus (Matthew))
came from the same stratum of rock and the same locality, and, with the correct understanding
of the valves of the type specimens of T. insignis, they may be closely compared, as is done
under the description of T. insignis.

Trematobolus is closely related to Schizambon. The ventral valve in both genera has an
oval pedicle opening in front of the beak at the anterior end of an external groove, tapering
toward the beak; it is the progressive track of the pedicle aperture, and strong, arched lines
indicate its successive positions in different stages of growth. (See Pl. LX XXIII, fig. lo,
which is a cast of the groove and opening in a thick shell.)

In Siphonotreta the pedicle opening is in front of the beak, but it does not advance with
the growth of the shell as in Schizambon and Trematobolus. The surface of Schizambon is
spinose while that of Trematobolus is nearly smooth. The shells of the latter are thick and
the former relatively thin. The muscle scars, as far as known, are essentially the same in
the two genera.

It is interesting to note that, with the exception of the pedicle groove and opening, 7’rema-
tobolus and Obolella are closely related.

The species now referred to the genus Trematobolus are: T. insignis Matthew, T. pristinus
(Matthew), 7. kempanum (Matthew), and T. excelsis Walcott.

T. excelsis occurs in the Lower Cambrian of eastern central California. It is one of the
oldest of the Cambrian brachiopods. The three species from New Brunswick are from near
the base of the Middle Cambrian.

SIPHONOTRETIDA. 617

.. TREMATOBOLUS EXCELSIS Walcott.

Plate LX XXII, figures 8, 8a—b.
Trematobolus excelsis WaLcott, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, pp. 80-81, Pl. VIII, fig. 8. (Described

and discussed as below as a new species. Fig. 8 is copied in this monograph, Pl. LX XXII, fig. 8.)

Shell transversely oval in outline, with both valves obtusely acuminate. . Ventral valve
strongly convex, with the minute beak at the posterior margin above a low area; the slope
from the highest poimt of the valve, a little back of the center, is greatest toward the beak
and nearly uniform to the front and sides of the valve. Pedicle opening unknown, as no
exterior or cast of the exterior of the valve occurs in the material collected; two casts of the
interior show the cast of the foramen at about the same position as in JT. insignis Matthew and
other species of the genus. Dorsal valve slightly more transverse than the ventral and about
two-thirds as convex; a very slight median flattening occurs at the anterior margin that extends
back on the valve, nearly to the beak in some specimens; otherwise the convexity is distributed
as in the ventral valve.

Surface marked by a few concentric lines of growth. The shell is rather thin, except
over the umbonal and posterior portions of the ventral valve, where it is moderately thick.
Its substance is now calcareous, and appears like that of 7. insignis; the original shell may
have been caleareocorneous. A ventral valve 18 mm. in length has the same width; a large
dorsal valve 22 mm. long has a width of 27 mm.

The area of the ventral valve is short and divided midway by a depressed subtriangular
false pedicle furrow; the presence of pits on each side of the anterolateral margins of the
false pedicle furrow indicates that the area at these places projected in the same manner as
that of 7. insignis Matthew and T. kempanwm (Matthew). (Compare Pl. LX XXII, fig. 8,
with Pl. LX XXIII, fig. 1c, and with Pl. LXXXIV, fig. 5.) The cast of the interior of the
ventral valve shows a median ridge with the cast of the pedicle opening at about the posterior
sixth of the length of the valve; only the imperfect outlines of the splanchnocele are known;
the main vascular sinuses are outlined for a short distance back of the transverse center suffi-
ciently to indicate that their position was about the same as in 7. kempanum. The position

- of the anterior lateral (j) muscle scar is clearly shown just outside of the main vascular sinuses;
it is elongate oval m outline and a little in advance of the transmedian scar (i); the umbonal
muscle scars are close to the median furrow, asin T. kempanum.

Interior of dorsal valve unknown.

Observations.—This fine species differs from all other known species of the genus in having
the ventral valve more convex than the dorsal and in its greater size. It is the oldest species
of the genus, occurring as it does well down in the section of the Lower Cambrian strata, in
association with Olenellus. There are a large number of specimens of the exterior of the
dorsal valve, but only two interior casts of the ventral valve. The dorsal valve of 7. pristinus
(Matthew) and 7. kempanuwm (Matthew) also greatly outnumbers the ventral valve in the
collections. This circumstance may be owing to the presence of the foraminal furrow and
interior median furrows; these would cause the shell of the ventral valve to break more readily
than that of the dorsal.

FORMATION AND LOCALITY.—Lower Cambrian: (58) Sandstones in the lower portion of 3d of the Waucoba Springs
section; (312) sandstones of 3d of the Waucoba Springs section; and (312a) shales of 3b of the Waucoba Springs section;
all east of the Saline Valley road, east of Waucoba Springs [see Walcott, 1908f, p. 187, for position in section], Inyo
County, California.

(176 and 178a) Shales and interbedded limestones between massive limestones containing Archxocyathus at
the south end of Deep Spring Valley; and (176a) sandstone on ridge east: of the head of Mazouka Canyon, Inyo Range;
both in Inyo County, California.

TREMATOBOLUS INSIGNIS Matthew.

Plate LX XXIV, figures 5, 5a-c.

Trematobolus insignis MatrHEw, 1893, Canadian Rec. Sci., vol. 5, pp. 276-279, figs. la-d, p. 276. (Described and
discussed as a new species. The specimens represented by figs. la and 1b are redrawn in this monograph, Pl.
LXXXIV, figs. 5b and 5, respectively. Figs. 5¢ and 5a of this monograph are drawn from casts of the typical
specimens, Matthew, 1893a, figs. la and 1b, respectively.)

618 CAMBRIAN BRACHIOPODA.

Trematobolus insignis Matthew, Haut and CrarKeE, 1892,¢ Eleventh Ann. Rept. State Geologist New York for 1891,

p. 252, fig. 268. (No text reference. Figs. 263 (la—d) are copied from Matthew, 1898a, figs. la-d, respectively,

. 276. ;
cm Matthew, Haut and Crarxks, 1892,¢ Forty-fifth Ann. Rept. New York State Museum for 1891,

p. 568, fig. 263. (Copy of preceding reference.)

Trematobolus insignis MattHEw, 1894, Trans. Roy. Soc. Canada for 1893, Ist ser., vol. 11, sec. 4, No. 8, pp. 88-90,
Pl. XVI, figs. 4a-d. (Except for the last paragraph, this is a copy of Matthew, 1893a, pp. 276-279. Figs. 4a—d

are copied from Matthew, 1893a, figs. la—d, respectively, p. 276.)

Trematobolus insignis MATTHEW, 1895, Trans. New York Acad. Sci. for 1894-95, vol.14, pp. 122-125, Pl. IV, figs. 2a-d.

(Text and figures copied from preceding reference.)

Trematobolus insignis MATTHEW, 1895, Bull. Nat. Hist. Soc. New Brunswick, vol. 3, No. 13, p. 95, figs. la-d. (No
text reference. Figs. la—d are copied from Matthew, 1895a, Pl. IV, figs. 2a—-d, respectively.)
Trematobolus insignis MatrHEW, 1898, Bull. Nat. Hist. Soc. New Brunswick, vol. 4, pt. 1, No. 16, p. 35, figs. la-d.

(No text reference. Figs. la—d are copied from Matthew, 1895a, Pl. IV, figs. 2a-d, respectively.)

Shell subcircular in outline, biconvex, valves inarticulate. Ventral valve gently convex,
with the minute beak at the posterior margin, and above a low area. Pedicle opening a rather
large, simple, oval opening at the anterior end of a furrow that gradually narrows toward the
beak, where it terminates; from the lines of growth in the furrow indicating progressive stages
of the advance of the foramen it is evident that the foramen began at or just in advance of the
beak, and advanced with the growth of the shell in the same manner as the foramen of Schizam-
bon (Pl. LX XXIV, fig. 1); the length of the foraminal furrow varies from one-third to two-
fifths of the length of the valve.

The substance of the original shell appears to have been entirely removed by solution and
replaced by the limestone. The closely related species T. kempanwm (Matthew) has a calcareo-
corneous shell. That the shell was strong is indicated by the depth of the vascular markings
and muscle scars. The outer surface is marked by a few concentric lines of growth. The type
specimen is 9 mm. in diameter.

The area of the valve is short and divided midway by a depressed, narrow, subtriangular
space, bounded by narrow, slightly elevated ridges that originate just beneath the ‘bani and
diverge a little toward the margin of the area, wines they unite with the margin and extend
aed so as to form two short projections, one on each side of the pseudopedicle furrow on the
area; the area slopes forward from the beak at an angle of about 15°; it is marked by rather
strong transverse lines of growth.

There are no traces of the posterior portion of the foraminal furrow on the interior of the
valve; it is entirely within the substance of the shell. The splanchnoceele extends to about
the center of the valve; in front of the area a low, broad swelling begins that extends forward
beyond the foraminal opening, where it divides so as to leave a short depressed space, and
within, a narrow median ridge; on each side and in front of the line of the pedicle opening there
are the obscure outlines of the spaces occupied by the scars of the points of attachment of the
central, middle lateral, and outside lateral muscles, very much as in Obolus (Pl. VII); these
muscle-bearing spaces are finely shown in T. kempanwm (Matthew) and T. pristinus (Matthew)
(Pl. LX XXIII, figs. 1d, 1j, 2c). The sinuses of the main vascular canals are broad and strong;
they start near the front margin of the area near the median line and extend outward and forward
subparallel to the outer margin of the valve to about the transverse median line, beyond which,
owing to the broken specimen, they have not been traced. The umbonal muscle scars occur
on each side of the median line just beneath the projections of the area beside the false pedicle
furrow; they are small and located on a low ridge. The transmedian and anterior lateral mus-
cle scars are elongate oval in outline, close to the outer margin of the main vascular sinus, and
placed on a rounded, low ridge; the transmedian scar extends a little outside of the anterior
lateral scar at its anterior end; as already stated, the central scars and the middle and out-
side lateral scars probably occurred in the spaces on each side of the anterior end of the low
median ridge.

a This date (1892) is taken from the title-page and is used throughout this monograph, but the work is clearly antedated, the correct
date being 1893 or 1894.

SIPHONOTRETID. 619

The opening of the foramen in the interior of the valve is on the low median ridge at a point
three-fifths of the distance from the area to the anterior end of the median line of the splanch-
noceele (visceral area). ‘

Dorsal valve unknown.

Observations—This species is known only by the type specimens of Matthew. These
include a matrix of the ventral valve, represented by Plate LX XXIV, figure 5b, a cast of the
interior of a broken ventral valve, figure 5, a fragment of the exterior of a ventral valve showing
the foraminal furrow, and a fragment of the cast of the outer surface. As stated under the
description of the genus, Matthew [1893a, p. 276] mistook the matrix of the ventral valve for
the interior of a ventral valve, and the cast of the interior of a ventral valve for a dorsal
valve. The true relations of the specimens are readily seen by comparing them with the speci-
mens of closely allied species on Plate LX XXIII.¢

The type material was collected from a layer of rock that is identical with, or is nearly at
the same horizon as, a layer at the same locality carrying numerous specimens of Trematobolus
pristinus (=Protosiphon pristinus Matthew). I would consider the latter a synonym were it
not for the position and size of the vascular sinuses in the ventral valve, which are located well
out toward the outer margin (compare Pl. LX XXIV, fig. 5, with Pl. LX XXIII, fig. 2c), while
in T. pristinus they are much nearer the median line of the valve. The interior of the ventral
valve of T. insignis is more like that of T. kempanwm (Matthew). (Compare Pl. LXXXIV,
fig. 5, with Pl. LX XXIII, figs. 1c, i.) Until a larger series of specimens representing T. insignis
is collected the diagnosis of the genus must depend largely upon the material representing T.
kempanum.

FoRMATION AND LOCALITY.—Middle Cambrian: (301 [Matthew, 1895a, p. 123]) Sandstones of Division 1b2 of
Matthew, on Hanford Brook, St. John County, New Brunswick, Canada.

TREMATOBOLUS KEMPANUM (Matthew).
Plate LX-X XIII, figures 1, la-o.

Protosiphon kempanum MattHEw, 1897, Geol. Mag., new ser., dec. 4, vol. 4, pp. 70-71, figs. 14, p. 70. (Described
and discussed as a new species.)

Protosiphon kempanum MartHEw, 1898, Trans. Roy. Soc. Canada for 1898, 2d ser., vol. 4, sec. 4, No. 2, p. 131, Pl. I,
figs. laf. (Text is almost an exact copy of the preceding reference. Figs. Ja—d are copied from figs. 2, 1, 3,
and 4, respectively, of the preceding reference.)

General form subcircular to rounded ovate, biconvex, with the dorsal valve about one-
third more convex than the ventral; outline of ventral valve obtusely acuminate and dorsal
valve broadly rounded posteriorly. Beak of ventral valve marginal above a well-defined area;
just in front of the beak a narrow furrow starts that marks the path of advance of the pedicle
opening; this furrow is usually from one-fourth to one-third the length of the shell and grad-
ually widens and deepens up to the oval pedicle opening; strong lines of growth, with the
curvature of the posterior side of the opening, mark the stages of growth and advance of the
opening; these are beautifully shown by the cast of the furrow and opening illustrated by
Plate LX XXIII, figure lo. The furrow and pedicle opening are entirely in the layers of the
shell and do not cause a projection on the interior of the valve; the opening is compressed
im some specimens, but it is usually of good size, as is shown by a cast of it that extended from
the outer to the inner surface; this is represented by figure le. The opening is of the same
character as that of Schizambon, except that it is through a thick shell.

Dorsal valve proportionally a little shorter than the ventral; beak marginal.

Surface marked by a few concentric lines of growth; the inner surface appears to have
been smooth. The specimens are preserved in a fine-grained sandstone, and usually in the
form of casts; a few show portions of the shell, and these indicate that it was of a calcareo-
corneous nature and built up of several rather strong layers or lamelle. This is also indicated
by the cast of the pedicle furrow and opening (fig. lo).

a {sincerely regret being obliged to differ so greatly with my friend Doctor Matthew on the interpretation of the types of this species and of
the genus T'rematobolus. i :

620 - CAMBRIAN BRACHIOPODA.

The largest ventral valve in the collection has a length of 14 mm. and a width of 13.5 mm.
A dorsal valve 13 mm. long has the same width.

The area of the ventral valve slopes backward and rises from the plane of the margins
of the valve at an angle of about 45°. It is divided midway by a false pedicle area that
varies in width; it is subtriangular in outline, slightly depressed, and has a narrow median
furrow of varying depth that is marked by strong lmes of growth; on each side of the inner
end of this furrow the area is extended forward as a toothlike projection, very much as in
Bicia (Pl. L) and Obolella (Pl. LV). The area is marked by transverse lines of growth sub-
parallel to its anterior margin. The cast of the area (Pl. LX XXIII, figs. le, 1d, 1g, li, and
1k) shows the pits made by the projections of the area next to the false pedicle furrow; it
was these pits in the cast of the ventral valve of T. insignis (Pl. LX XXIV, fig. 5) that Matthew
[1893a, p. 276] mistook for the dental sockets of the dorsal valve.

The splanchnoceele of the ventral valve is large and clearly shown; the low, broad, rounded

median ridge is about one-half the length of the valve; it broadens out near the pedicle opening |

and again toward the front; it is marked by a narrow median depression back of the pedicle
opening, and, in front of the pedicle opening, by a central, elongate swell surrounded by a
narrow furrow. The pedicle opening is clearly defined on nearly all casts of the valve; it is
situated about two-fifths the distance from the area to the front end of the ridge on which
it occurs. On each side, a short distance back of the front end, an area is outlined that extends
obliquely backward to the main vascular sinus; this area may be depressed below the general
surface or raised above it; it corresponds to the area in the ventral valve of Obolus, in which
the central muscle scars and the middle and outside lateral scars occur. (Compare Pl. LX XXIII,
figs. 1c, Id, with Pl. VII, figs. 5 and 13; also with Pl. XIV, figs. la and 4a.) The transmedian
and anterior lateral muscle scars occur on a rounded ridge just outside of the main vascular
sinuses (Pl. LX XXIII, fig. 1d). The umbonal muscle scars are oval in outline and situated
close to the posterior end of the central median ridge, and between the ridge and the trans-
median muscle scars. The impressions made by the main vascular canals are broad, strong,
and continued to the anterior third of the valve; they originate beside the median ridge close
to the area, and curve outward and then inward beyond the center of the valve.

The area of the dorsal valve is narrow and divided by a central, slightly depressed, tri-
angular space; it is marked by transverse lines of growth and appears to be on the same plane
as the margins of the valves. The splanchnoccele of the dorsal valve extends forward beyond
the center of the valve; it is divided by a narrow, median septum, and has an oval depression
in it a little back of the anterior lateral muscle scars; the central muscle scars are large, oval
in outline, and situated on the outer slope of the rounded ridge about the central depression;
the anterior lateral scars are small and placed on the rounded ridge in front of the central
depression and close to the median septum. A low, rounded ridge extends obliquely forward
into the valve from each side of the median septum; these probably mark the position of
vascular canals extending forward from the visceral area; they are shown in Plate LX XXIII,
figures 11 and 1n. The transmedian and anterior lateral muscle scars are located close to
the outer edge of the main vascular sinus, well back on the posterolateral part of the valve.
The main vascular sinuses start back of the visceral area near the median septum and curve
outward and then forward about halfway between the central muscle scars and the margin
at the center of the valve, and then a little inward before terminating near the front margin.

Observations.—This fine shell was the type of Matthew’s genus Protosiphon [1897a, p. 68].
I find it to be congeneric with Trematobolus insignis Matthew, and rather closely related to
that species. This may be seen by comparing Plate LX XXIII, figures Ic, 1d, with Plate
LXXXIV, figure 5. The pedicle furrow and aperture is much like that of Schizambon typicalis
Walcott (Pl. LXXXIV, figs. 1, 1a) except that it is in a thick shell, while that of the latter
species is in a relatively thin shell. In 1898 Mrs. Walcott and I collected a large series of
specimens at the typical locality, as I wished to illustrate fully this the oldest of the Siphono-
tretidz of the Schizambon type. The shell occurs above the Olenellus zone, at about the same
general horizon as T. insignis and T. pristinus.

re

SIPHONOTRETID. 621

The specific name was given in honor of Prof. J. F. Kemp, of Columbia University, New
York City.
FORMATION AND LOCALITY.—Middle Cambrian: (2u) Lowest beds exposed on the south side of Long Island; and
(308g) shales of Division 163 or 1b4 [ Matthew, 1897, p. 71] of Matthew’s section on Long Island; both in Kennebecasis
Bay [see Matthew, 1898a, pp. 124 and 127], St. John County, New Brunswick, Canada.

TREMATOBOLUS PRISTINUS (Matthew).

Plate LX XXIII, figures 2, 2a—h; Plate LX XXIV, figure 6.

Obolus pristinus MattHew, 1895, Trans. New York Acad. Sci. for 1894-95, vol. 14, pp. 121-122, Pl. IV, figs. la-d.
‘Described as a new species. The specimen represented by figure 1c is redrawn in this monograph, PI.
LXXXIII, fig. 2f.)

Obolus pristinus MatTHEW, 1902, Trans. Roy. Soc. Canada, 2d ser., vol. 8, sec. 4, No. 3, p. 96, Pl. I, figs. 8a-d. (Char-
acterized. Figs. 8a—d are copied from figs. la-d, respectively, of the preceding reference.)

General form biconvex, subcircular to short ovate. Ventral valve rounded acuminate,
sometimes a little broader than long; beak marginal above a low area. Pedicle opening at
the anterior end of a furrow th’&t gradually narrows to the beak; the foraminal furrow varies
in length from about one-third to two-fifths the length of the valve; it is situated in the thick-
ened part of the shell and does not produce a ridge on the interior of the valve. Dorsal valve
proportionally a little shorter than the ventral; beak marginal; area, if present, unknown.

Surface marked by fine concentric striz and lines of growth that show as the front margins
of imbricated lamelle of the shell; very fine radiating strize (also a few radiating, slightly
elevated lines) occur on some specimens, but whether they belong on the epidermal layer or
one of the inner lamellz is unknown; the inner surface is slightly roughened. The substance
of the shell has been replaced by the calcareous matter of the matrix, but from the calcareo-
corneous nature of the shell of 7. kempanum (Matthew) it is probable that the original shell
of this species was of the same nature. The shells vary in size from 5 to 13 mm. in length; the
average is about 9 mm.

The area of the ventral valve is short; otherwise, nothing is known of it. The splanch-
noceele extends nearly to the center of the valve; a low ridge starts near the area, and, gradu-
ally widening, passes beyond the pedicle opening into an oval depression forming the anterior
portion of the visceral cavity; the ridge back of the pedicle opening is marked by a slightly
raised median line; the space on each side, between the median ridge and the main vascular
sinuses, has a narrow band across the front that extends from each side of the central depressed
area diagonally backward to the main sinuses; these bands correspond in position to the spaces
occupied by the central muscle scars and the transmedian and outside lateral scars (compare
Pl. LX XXIII, fig. 2b, with Pl. VII, fig. 13, of Obolus); the anterior lateral muscle scar is close
to the main vascular sinus, nearly opposite the pedicle opening. The main vascular sinuses
start near the area on each side of the low median ridge, and, with a gentle outward curve,
pass the center, and then, with a slight inward curve, reach nearly to the front margin; they
do not extend laterally beyond a vertical line drawn midway between the center and lateral
margins of the valve. Fine, irregular, secondary radial canals extend outward from the main
canal toward the margins.

The splanchnoceele of the dorsal valve extends beyond the center; a very narrow median
septum is shown, or else a broad, low, rounded ridge. The main vascular sinuses start near
the median line, close to the posterior margin, and curve forward, subparallel to the lateral
margins of the valve, gradually getting farther away from the margins as they pass the trans-
verse center of the valve. The central muscle scars are elongate oval in outline and situated
back of the center of the valve; the anterior laterals are small and close to the median line.

Nothing is clearly shown of the details of the area of the dorsal valve; it was probably
similar to that of 7, kempanum (Matthew). (Compare figs. 2f and 2¢ with figs. 11 and 1m, PI.
LXXXTII.)

Observations.—This species is closely related to T. insignis Matthew, reference to which
is made under that species; it differs in the position of the main vascular sinuses of the ventral

622 CAMBRIAN BRACHIOPODA.

valve, and in the size of the splanchnocele. TZ. kempanum is a larger shell with different vas-
cular and other scars in the interior of the ventral valve. Figures 2, 2a—d represent specimens
collected by S. Ward Loper for the United States National Museum, and figures 2e—h represent
the specimens in Matthew’s collection, now at the University of Toronto.

FORMATION AND LOCALITY.—Middle Cambrian: (301 [ Matthew, 1895a, p. 122]) Sandstones of Division 162; (2h)

sandstones of Division 1b2; and (2i and 2k) sandstones of Division 1b3; all in Matthew’s [1895a, p. 108] Protolenus
zone, on Hanford Brook, St. John County, New Brunswick, Canada.

Genus SCHIZAMBON Walcott.
[czt6w, I divide; and dufwv, a raised edge.]

Schizambon Waxcort, 1884, Mon. U. S. Geol. Survey, vol. 8, pp. 69-70. (Described and discussed as a new genus.)

Schizambonia OEHLERT, 1887, Manuel de conchyliologie, by Fischer, p. 1266. (Described in French.)

Schizambon Walcott, Haut and CrarKz, 1892, Eleventh Ann. Rept. State Geologist New York for 1891, pp. 253-254.
(Described and discussed.)

Schizambon Walcott, Harn and CrarKe, 1892, Forty-fifth Ann. Rept. New York State Museum for 1891, pp. 569-570.
(Copy of preceding reference.)

Schizambon Walcott, Hart and CrarxKs, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, pp. 113-117. (Copies
the original description, Walcott, 1884b, p. 69, and discusses genus and species referred to it.)

Schizambon Walcott, WINCHELL and ScHucHERT, 1895, Nat. Hist. Minnesota, Geology, vol. 3, pt. 1, Paleontology,
p- 360. (Copies the original description, Walcott, 1884b, p. 69, and discusses genus.)

Schizambon Waucorr, 1908, Smithsonian Mise. Coll., vol. 53, No. 4, Pl. XI, and pp. 142 and 146. (Classification of
genus. )

This genus is described in Monograph VIII of the United States Geological Survey [Walcott,
1884b, p. 69] and very fully in Hall and Clarke’s monograph [1892¢e, p. 113].

The type species is illustrated in this memoir on Plate LXXXIV. The other species
now referred to the genus are S.? esthonia Walcott, 8. manitouensis Walcott, and S. priscus
Matthew. As stated in the original description [Walcott, 1884b, p. 69] Siphonotreta fissa
Kutorga appears to belong to the genus, and Hall and Clarke [1892b, pp. 115-116] include
Schizambon? canadensis (Ami);* Messrs. Winchell and Schuchert [1895, pp. 361 and 362] ten-
tatively include S.? dodge and S.? locket, and Mr. George H. Hudson [1904, p. 284] describes
a new species, Schizambon duplicimuratus, from the Chazy limestone on Valcour Island, Lake
Champlain, New York.

Type.—Schizambon typicalis Walcott.

SCHIZAMBON ? ESTHONIA 0. sp.
Plate LXXXIV, figure 4.

This species is represented by a single specimen of the ventral valve. It is nearly circular
in outline and moderately convex. Apex a little in advance of the posterior margin; a slight
flattening back of the apex outlines a faint false area. A wedge-shaped depression extends
from the sharp apex forward a short distance to its larger end where the large oval foramen
occurs; this depression is similar to that in Schizambon typicalis Walcott and S. fissa (Kutorga) ;
itis marked by fine lines of growth back of the foramen. Surface marked by fine concentric lines
of growth and three narrow, low, concentric ridges or varices of growth; the entire surface is
finely granulated, the spactiles "heninee formed apparently by the crossing of “Gin, curving, oblique
furrows that start on the sastanelstenl margin and curve forward slollignne i> across Une shell,
crossing so as to form rhomboidal spaces in which the granules occur. This type of surface is
unlike the spinose surface of S. typrcalis. It suggests the surface of Micromitra and some forms
of Obolus (Westonia). From some points of view the crossing of the depressed lines gives a
punctate appearance to the surface.

It may be that this shell belongs to some other genus, but with the present information ws
is referred to Schizambon.

The specific name is derived from Esthonia.

FORMATION AND LOCALITY.—Upper Cambrian: (336h) Ungulite grit, at Baltischport, Esthonia, Russia.

@ Siphonotreta scotica canadensis Ami, 1887, Ottawa Naturalist, vol. 1, No. 9, p. 124,

SIPHONOTRETID. 623

= SCHIZAMBON MANITOUENSIS 0. sp.
Plate LX XXIV, figures 3, 3a-e.

General form and convexity much like those of Schizambon typicalis Walcott, also surface
characters if the influence of the different matrix is allowed for. The differences between the
two species are in the larger foramen in S. manitouensis; in a shorter depression before the beak;
in the interior markings of the dorsal valve and the strong area of the dorsal valve (Pl. LX XXIV,
fig. 3c). There may be a similar area in S. typicalis, but owing to the condition of preservation
it has not been observed.

The finely spinose surface is rarely seen, as it adheres to the matrix. The usual appearance
of the shell is like that shown by figure 3. The average shell has a length of 4.5 mm., width
about the same. Substance corneous.

The specific name is derived from Manitou, Colorado. :

ForMATION AND LOCALITY.—Lower Ordovician: (186 and 186a)@ Near line of contact between the red and gray
Ordovician limestone, in siliceous red limestone about 30 feet (9.1 m.) above the pre-Cambrian rocks, Williams Canyon,
Manitou; and (360) red siliceous limestone near Colorado Springs; both in El Paso County, Colorado.

SCHIZAMBON PRiIscUS Matthew.

se Plate LXXXIV, figures 2, 2a-e.

Schizambon priscus MarruEw, 1901, Bull. Nat. Hist. Soc. New Brunswick, vol. 4, pt. 4, No. 19, pp. 277-278, Pl. V,
figs. da-d. (Described and discussed as a new species. None of the specimens figured are reproduced in this
monograph. )

Schizambon priscus MartHEw, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, pp. 187-189, Pl. XI,
figs. 6a-d.. (Description and figures copied from preceding reference.)

Shell small and subcircular to transversely ovate, moderately convex. Ventral valve
slightly acuminate, with the apex above a short false area, and lower than the umbo. Foramen
small, oval, and opening externally into an elongate groove tapering toward the beak; back of
the foraminal opening a tapering ridge extends to the beak, leaving a narrower groove on each
side. In the interior of the shell the edges of the tapering groove are slightly elevated and the
foraminal opening appears to be of about the same size as the external opening. On some
specimens of the ventral valve, on each side of the foramen on the outer surface, a narrow depres-
sion extends forward and slightly outward nearly to the front margin; this character corresponds
to the low ridges in the ventral valve of Schizambon typicalis Walcott (Pl. LX XXIV, fig. 1a).

The dorsal valve is less convex than the ventral, and its beak is marginal. The interior
of the valve shows a median ridge of varying strength, and the same is true of the ridges indi-
cating the narrow main vascular canals. In figure 2¢ the anterior portion of the median
ridge is shown, also the oval, widely separated central muscle scars (h) and the small anterior
lateral sears (j); mm figure 2d the main vascular canals and the central portion of the median
sinuses are shown. In figure 2e there is only a trace of vascular markings.

Surface as preserved, marked by very fine radiating and concentric ridges that form on some
shells a cancellated pattern; the fact that many shells adhere by the outer surface to the matrix
leads me to suspect that the outer surface is roughened and probably spinose as in other species
of the genus. The average size of the shells is about 4 mm. in length and width. Shell substance
corneous.

FORMATION AND LOCALITY.—Upper Cambrian: (10f and 10g) Shales on the east branch of Barachois River, 0.75
mile (1.2 km.) north of the crossroad from Boisdale to Upper Leitches Creek; (10h) at same locality as Locality 10f,
but in shales of a slightly different horizon; (10e) shales on the east branch of Barachois River, 0.5 mile (0.8 km.)
north of the crossroad from Boisdale to Upper Leitches Creek; (101) shale on east bank of Barachois River, 6 miles
(9.6 km.) from Little Bras d’Or Lake; (13h) shale on the east bank of Barachois River, 1.5 miles (2.4 km.) north of
Boisdale; (10k) shale on west bank of Barachois River, about 0.25 mile (0.4 km.) north of the Boisdale road; (10d)
shale on the west side of Barachois River, 0.125 mile (0.2 km.) north of the Boisdale road, opposite McMullin’s place;

(10i) shale in high bank on the west side of Barachois River, just north of the Boisdale road; (307 [ Matthew, 1903, p.
188]) shales of Division C3c¢ of Matthew on McLeod Brook (=Barachois River); (8q) shale in Barachois Glen, 4 miles

@186a is the type locality.

624 CAMBRIAN BRACHIOPODA.

(6.4 km.) south of Little Bras d’Or Lake; (8h) shale and shaly limestone on McNeil Brook, 1.5 miles (2.4 km.) east
of Marion Bridge; and (372e [Matthew, 1903, p. 50]) shales on McMullins Brook, near McLeod Brook (=Barachois
River); all in eastern Cape Breton, Nova Scotia, Canada.

(308 [Matthew, 1901a, p. 278]) Shales of Division C3c of Matthew at Navy Island, St. John Harbor, St. John County,
New Brunswick, Canada.

Specimens somewhat doubtfully referred to this species occur at the following locality:

Upper Cambrian: (10c) Shales ina horizon 50 feet below that of Locality 10k, on the west side of Barachois
River, eastern Cape Breton, Nova Scotia, Canada.

ScH1zaMBON TYPICALIS Walcott.
Plate LXXXIV, figures 1, la~d.

Schizambon typicalis Waucort, 1884, Mon. U. 8. Geol. Survey, vol. 8, pp. 70-71, Pl. I, figs. 3, 3a-d. (Described and
discussed as a new species. Figs. 3, 3a-d are copied in this monograph, Pl. LX XXIV, figs. 1a, 1, lc, 1b, and
1d, respectively.)

Schizambon typicalis Walcott, Hatt and Crarxs, 1892, Eleventh Ann. Rept. State Geologist New York for 1891, p.
253, Pl. IV, figs. 18-20. (Mentioned under genus Schizambon. Fig. 18 is copied from Walcott, 1884b, Pl. I,
fig. 3a.)

Schizambon typicalis Walcott, Hatt and CrarxKe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, pp. 114, 116,
and 117; fig. 65, p. 114; and Pl. IV, figs. 27-30. (Mentioned in discussion of genus Schizambon. Fig. 65 is
copied from Walcott, 1884b, Pl. I, fig. 3a. Figs. 27 and 29 are copied from figs. 19 and 20, respectively, of the
preceding reference.)

This species is fully described in Monograph VIII of the United States Geological Survey
[Walcott, 1884b, pp. 70-71]. There is little to add to the description. For comparison with
the other species the original figures are reproduced.

Among the fossils occurring in limestone bowlders from, Locality 30w there is a single
specimen of a ventral valve of a shell that appears to be identical with Schizambon typicalis.
The points of identity are: (a) general form; (b) shape of foraminal opening; (c) fine, ele-
vated, concentric striz. The only difference is the greater convexity, which is owing, I think,
to the character of the matrix, the Nevada specimen being in a shaly limestone and somewhat
compressed.

FoRMATION AND LOCALITY.—Lower Ordovician: (201a) Pogonip limestone, east slope of the ridge east of Hamburg —

Ridge, Eureka district [ Hague, 1892, Atlas], Eureka County, Nevada.

Upper Cambrian: (30w) Drift bowlder of limestone supposed to have come from 1a of the Notch Peak limestone
on Notch Peak [Walcott, 1908f, p. 175], found about 2 miles (3.2 km.) south of Marjum Pass, House Range [Walcott,
1908f, Pl. XIII], Millard County; (83d) thin-bedded blue limestone at the base of the first high point southwest of
the J. J. Thomas ranch, on the east side of the Fish Spring Range, Juab County; and (54c) about 1,100 feet (335.3 m.)
above the Middle Cambrian and 120 feet (36.6 m.) below the top of the Upper Cambrian in the central portion of the
limestone forming 1 of the St. Charles formation [Walcott, 1908f, p. 192], in Blacksmith Fork Canyon, about 10 miles
(16.1 km.) east of Hyrum, Cache County; all in Utah.

Genus SIPHONOTRETA de Verneuil.}
|eidwv, a siphon or tube; rpyzoc, perforated.]

Crania EicHwaLp (in part) [not Rerzrus], 1829, Zoologia specialis, vol. 1, p. 273. (Described in Latin. The genus
includes species other than those belonging with Siphonotreta.)

Terebratula ErcHWA.p (in part) [not LHwyn], 1840, Jour. Natur- und Heilkunde Medizinischen Akad. St. Petersburg,
pts. land 2, p. 138 (p. 24 in secord part of one edition). (Merely places ‘‘ Crania unguiculata and C’. verrucosa”
in this genus.)

. Terebratula KicHwaup, 1842, Die Urwelt Russlands, Hit. 2, p. 145. (Merely mentions ‘‘ Terebratula unguiculata.’’)

Re ieneie DE VERNEUIL, 1845, Géologie de la Russie d’Europe, by Murchison, de Verneuil, and de Keyserling,
vol. 2, pt. 3, p. 286. (Described in French as a new genus.)

Siphonotreta de Vereuil, Kurtorea (in part), 1848, Verhandl. Russ.-kais. min. Gesell. St. Pacanus for 1847, No:
12, pp. 261-263. (Described and discussed in German. Notes on the genus occur at various places on pp.
250-260.)

Siphonotreta de Verneuil, Morris, 1849, Annals and Mag. Nat. Hist., 2d ser., vol. 4, pp. 315-320. (Notes on the genus
and its generic relations.)

a This species is somewhat doubtfully identified from this locality.
b The synonymy for this genus is not complete; it includes only those references dealing with the species taken up in this monograph.

SIPHONOTRETIDZ. 625

Siphonotreta de Verneuil, Morrts, 1850, Rept. British Assoc. Ady. Sci. for 1849, Notices and Abstracts, pp. 57-58.
(Notes on the genus.)

Siphonotreta de Verneuil, Davipson, 1853, British Fossil Brachiopoda, vol. 1, Introduction, No. 3, pp. 131-133.
(Described and discussed.)

Siphonotreta de Verneuil, E1cHwaup, 1860, Lethzea rossica, ancienne période, vol. 1, sec. 2, p. 915. (Described in
French.

Stphonotreta = Verneuil, SEEBAcH, 1865, Zeitschr. Deutsch. geol. Gesell. for 1865, Bd. 17, Heft. 2, p. 341. (Discussed
in German.)

Siphonotreta de Verneuil, Davrpson, 1866, British Fossil Brachiopoda, vol. 3, pt. 7, No.1, p. 75. (Mentioned.)

Siphonotreta de Verneuil, QUENSTEDT (in part), 1871, Petrefactenkunde Deutschlands, Abth. 1, Bd. 2, Brachiopoden,
pp. 673-674. (Described and discussed in German.)

Siphonotreta de Verneuil, Davipson, 1877, Geol. Mag., new ser., dec. 2, vol. 4, pp. 18-16. (Notes on the genus and
its generic relations.)

Siphonotreta de Verneuil, Zrrrex, 1880, Handbuch der Palontologie, Bd. 1, Abth. 1, pp. 665-666. (Described in

German.

Siphonotreta eee Davipson, 1883, British Fossil Brachiopoda, vol. 5, pt. 2, pp. 217-219. (Discussed.)

Siphonotreta de Verneuil, OEHLERT, 1887, Manuel de conchyliologie, by Fischer, p. 1265. (Described in French,
with figures of S. unguiculata and S. verrucosa.) :

Siphonotreta de Verneuil, Haut and CiarxKe, 1892, Eleventh Ann. Rept. State Geologist New York for 1891, pp.

252-253. (Described.)

Siphonotreta de Verneuil, Haut and Crarke, 1892, Forty-fifth Ann. Rept. New York State Museum for 1891, pp. 568-569.

(Text copied from preceding reference.)

Siphonotreta de Verneuil, Haun and CuarKe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, pp. 110-113.

(Described and discussed.)

Siphonotreta de Verneuil, WincHELL and ScHucHERT, 1895, Nat. Hist. Minnesota, Geology, vol. 3, pt. 1, Paleontology,

p. 358. (Copies the description given by Hall and Clarke, 1892c, pp. 110-111.)

Siphonotreta de Verneuil, Waucotr, 1908, Smithsonian Misc. Coll., vol. 53, No. 4, Pl. XI, and pp. 142 and 146. (Clas-
sification of genus.)

For the diagnosis of the genus, see Hall and Clarke [1892c, pp. 110-113].

The following notes are the result of the study of casts of a natural mold of the interior
of the two valves united that I worked out from a specimen of S. ungwiculata (Pl. LUX XX,
figs. 6, 6a—b) received from Dr. Fr. Schmidt, m which the transverse diameter is 18 mm.

The cast of the interior of the ventral valve shows that the visceral area was elevated
on a thickening of the shell, and that the muscle scars were attached in depressions in front
of and beside the elevated visceral area; the main vascular canal was also on a ridge where it
passed from the anterolateral edge of the visceral area. The poimts of attachment of the
central, outside lateral, and middle lateral scars are not clearly defined as distinct scars in the
specimens at hand, but the space occupied by them is very distinctly marked. It is very much
like that of Obolus apollinis Kichwald (Pl. VII). The points of attachment of the transmedian
and anterior lateral muscles are close to the elevated visceral area, just outside of the ridge
beneath the main vascular sinuses. The opening of the pedicle tube is not well preserved;
this feature is illustrated by Davidson [1877, Pl. Il, figs. 8 and 9].

The interior of the dorsal valve shows a thickening of the shell in front of the antero-
lateral muscle scars so as to form a transverse ridge that unites with the median ridge and a
ridge on each side that appears to have been beneath the main vascular canals; within the
subtriangular space thus formed the rather large anterolateral muscle scars occur as pits,
-and a little back of them, and of about the same size, the elongate oval central muscle scars;
outside of the lateral ridge occur three large oval scars that correspond in position to the trans-
median, outside lateral, and middle lateral scars of the dorsal valve of Obolus.

The specimens studied by Davidson illustrate the interior of the ventral valve somewhat
better than those before me, but the imterior of the dorsal valve does not appear to have been
so good.

Type.—Crama unguiculata Hichwald.

SIPHONOTRETA ? DUBIA N. sp.
Plate LXXXI, figures 7, 7a—b.
Shell small, subcircular in outline. Ventral vaive subconical, with the apex a short dis-

tance in front of the posterior margin and directed backward; it is truncated by a small, round
62667°—vo1 51, pr 1—12——40

626 CAMBRIAN BRACHIOPODA.

opening that penetrates through the shell, but whether the opening is contmued as a tube is
unknown; a false area is slightly indicated on the slope between the pedicle aperture and the
gently upward-arching posterior margin. Dorsal valve depressed in some examples so as to be
slightly concave between the minute beak at the posterior margin and the front; in other
examples it is flat and in some slightly convex. ;

Surface of both valves marked by concentric lines of growth and low ridges from which
spine bases extend across to the front edge of the next ridge, very much as in Siphonotreta
unguiculata (Eichwald) (Pl. LX:XX); the spine bases are short and scattered on the posterior
parts, numerous and elongated toward the front and lateral margins in the adult shells.

The average diameter of the valves is from 3 to 4 mm. Substance of shell probably
caleareocorneous; it is‘calcareous in the specimens, but this appears to have been the result
of replacement of the original shell by impure calcite, which has also replaced the substance
of associated trilobite tests. E

The generic reference is doubtful, as nothing is known of the interior of either valve. The
circular pedicle opening distinguishes the species from Schizambon typrcalis Walcott, which has
a similar spinose surface (Pl. LX XXIV, fig. 1d), and relates it to Siphonotreta. I thmk that
with full knowledge of this species it will be found to belong to an undefined genus, as it is not
probable that Siphonotreta was developed so early in Cambrian time.

This form owes its specific name to the doubtfulness of the generic reference.

ForMaTION AND LOcALITY.—Lower Cambrian: (1v) Shales of No. 3 of the Silver Peak group, Barrel Spring

section [Walcott, 1908f, p. 189], 3 miles (4.8 km.) north of Valcalda Spring and 4 miles (6.4 km.) west-northwest of
the Drinkwater mine, Silver Peak quadranele (U. S. Geol. Survey), Esmeralda County, Nevada.

SIPHONOTRETA UNGUICULATA (Hichwald).

Plate LX XXI, figures 6, 6a-e.

Crania unguiculata Ercawaup, 1829, Zoologia specialis, vol. 1, p. 274, Pl. IV, fig. 3. (Described in Latin as a new
species.) :

Crania sulcata Ercawatp, 1829, idem, p. 274, Pl. IV, fig. 4. (Described in Latin as a new species.)

Terebratula unguiculata Ercawawp, 1840, Jour. Natur- und Heilkunde Medizinischen Akad. St. Petersburg, pts. 1 and
2, pp. 138-140 (pp. 24-26 in second part of one edition). (Described in German.)

Terebratula unguiculata Ercuwatp, 1842, Die Urwelt Russlands, Hit. 2, p. 145, Pl. IV, figs. 2a-b. (Mentioned in
German.)

Siphonotreta unguiculata (Hichwald), p—E VERNEUIL, 1845, Géologie de la Russie d’ Europe, by Murchison, de Verneuil,
and de Keyserling, vol. 2, pt. 3, pp. 286-287, Pl. I, fig. 13. (Described in French.)

Siphonotreta unguiculata (Hichwald), Kurorea, 1848, Verhandl. Russ.-kais. min. Gesell. St. Petersburg for 1847, No.
12, pp. 264 and 284, Pl. VI, figs. la-d, 2a-c, 3a-c. (Described in German on p. 264.) ;
Siphonotreta unguiculata var. « Kurorca, 1848, idem, p. 284, Pl. VI, figs. da-e. (The description of this variety
may be incorporated with that of the species on p. 264; it is only mentioned, however, in the description of

Pl. VI, which is on p. 284.)

Siphonotreta wnguiculata var. 8 Kurorea, 1848, idem, pp. 264-265, Pl. VI, figs. 5a-d. (Characterized in German.)

Siphonotreta unguiculata var. 7 elongata Kurorea, 1848, idem, p. 265, Pl. VI, figs. Ga-b. (Characterized in German

- as a new variety.)

Siphonotreta unguiculata (Eichwald), Davmpson, 1853, British Fossil Brachiopoda, vol. 1, Introduction, No. 3, Pl.
IX, figs. 261-265, 269 and 270. (Mentioned on p. 133. Fig. 269 is copied from Kutorga, 1848, Pl. VI, fig. 1a.)

Siphonotreta unguiculata Ercawaxp, 1860, Lethzea rossica, ancienne période, vol. 1, sec. 2, pp. 915-916. (Described
and discussed in French.)

Siphonotreta wnguiculata (Eichwald), Scumipr, 1861, Archiv fir Naturkunde Liv-, Ehst-, und Kurlands, 1st ser., Bd.
2, p. 218. (Localities mentioned.)

Siphonotreta unguiculata (Eichwald), QuENsTEpT, 1871, Petrefactenkunde Deutschlands, Abth. 1, Bd. 2, Brachio-
poden, p. 674, Pl. LXI, figs. 23-27. (Discussed.)

Stphonotreta unguiculata (Eichwald), Davipson, 1877, Geol. Mag. new ser., dec. 2, vol. 4, footnote and figs. A and B,
p- 14; p. 15, Pl. II, figs. 7-11. (Described and discussed. Fig. 9 is copied in this monograph, Pl. LXX XI,
fig. 6c.)

Siphonotreta unguwiculata (Hichwald), Zrrren, 1880, Handbuch der Palzontologie, Bd. 1, Abth. 1, p. 666, figs. 489a—d.
(No text reference. Figs. 489a-d are copied from Davidson, 1853, Pl. IX, figs. 265, 264, 262, and 261, respec-
tively.)

Siphonotreta wnguiculata (Bichwald), Watcorr, 1884, Mon. U.S. Geol. Survey, vol. 8, p. 16, Pl. I, fig. 8. (Discussed.
Fig. 8 is copied from Davidson, 1877, Pl. II, fig. 9.)

SIPHONOTRETIDA. 627

Siphonotreta unguiculata (Bichwald), QuENsTEDT, 1885, Handbuch der Petrefactenkunde, Auflage 3, p. 755, Pl. LVIII,
fig. 53. (Discussed in German.)

Siphonotreta unguiculata (Hichwald), Gacen, 1890, Beitr. zur Naturkunde Preussens, yon Physikal.-oekonom. Gesell.
Konigsberg, 6, p. 23, Pl. I, fig. 3. (Characterized in German.)

Siphonotreta unguiculata (Hichwald), Hatn and OnarKe, 1892, Eleventh Ann. Rept. State Geologist New York for
1891, p. 253, Pl. IV, figs. 22-26. (Mentioned. Figs. 22 and 23 are copied from Davidson, 1877, Pl. Il, figs. 9
and 11, respectively. Figs. 24-26 are copied from Kutorga, 1848, Pl. VI, figs. 2c, 3b, al 3a, vagpead vel )

Siphonotreta unguiculata (Hichwald), Hann and CrarKe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, p. 111,
Pl. IV, figs. 22-26. (Mentioned. Figs. 22-26 are copied from those in the preceding reference, which see.)

The characters of this species are included in the generic description given by Messrs.
Hall and Clarke [1892c, p. 110]. It differs from S. verrucosa (Eichwald) in its broader outline
and more finely granulated and spinose surface. Figs. 6, 6a, and 6b are of a specimen received
from, Dr. Fr. Schmidt; fig. 6c is copied from Davidson [1877, PI. II, fig. 9].

FoRMATION AND LOCALITY. 2—Ordovician: (336g) Limestone in the vicinity of Zarskoe Selo; (836w) near Paw-
lowsk; and (336x) in the Archangel quarry on the Volkhof (Wolchow); all near St. Petersburg, Russia.

(886v) Echinospherites limestone at Reval; (337d) ‘“‘Brandschiefer” at Salla, near Erras, 85 miles (137 km.) east
of Reval; and (337e) ‘“‘Jewesche Schicht” at Altenhof, near Péddrus, 55 miles (88.6 km.) east of Reval; all in the
Government of Esthonia, Russia.

Drift bowlders of Echinosphexrites limestone at the following localities: (886i) Near Wehlau, 30 miles (48.3 km.)
east of Konigsberg, East Prussia; (386j) at Belschwitz, East Prussia; (886k) near Wormditt, East Prussia; and (3861)
near Marienwerder, West Prussia; all in Germany.

Passage beds between the Upper Cambrian and the Ordovician: (336e) Orthoceratite limestone at Pulkowa; (337m)
Orthoceratite limestone at Popowka; (887k) Orthoceratite limestone on the banks of Wolchow (Volkhof) River, near
Lake Ladoga; and (836y) glauconitic limestone at Popowka; all near St. Petersburg, Russia.

Orthoceratite limestone (‘‘Vaginatenkalk”) at the following localities: (886z) At Narwa; (337) at Erras, 85 miles
(187 km.) east of Reval; (837a) at Kusal, 25 miles (40 km.) east of Reval; (837b) © at Reval; (337¢c) on Odensholm Island,
55 miles (88.6 km.) west of Reval; and (3371) at Baltischport, west of Reval; all in the Government of Esthonia,
Russia.

SIPHONOTRETA VERRUCOSA (Hichwald).

Plate LX X XJ, figures 5, 5a-b.

Terebratula verrucosa HicHWALD, 1840, Jour. Natur- und Heilkunde Medizinischen Akad. St. Petersburg, pts. 1 and 2
pp. 140-141 (pp. 26-27 in second part of one edition). (Described in German.)

Siphonotreta verrucosa (Eichwald), bp VERNEUIL, 1845, Géologie de la Russie d’ Europe, by Murchison, de Verneuil, and
de Keyserling, vol. 2, pt. 3, p. 287, Pl. I, figs. 14a-d. (Described in French.)

Siphonotreta verrucosa pen Kutorea, 1848, Verhand]. Russ.-kais. min. Gesell. St. Petersburg for 1847, No. 12,
pp. 266-267, Pl. VII, fig.1. (Described in German.)

Siphonotreta verrucosa (Bichwald), Morais, 1849, Annals and Mag. Nat. Hist., 2d ser., vol. 4, Pl. VII, figs. 2a-d. (No
text reference. Description of plate on p. 321.)

Siphonotreta verrucosa (Kichwald), Davipson, 1853, British Fossil Brachiopoda, vol. 1, Introduction, No. 3, Pl. IX,
figs. 267 and 268. (Mentioned on p. 183.)

Siphonotreta verrucosa HicHwaup, 1860, Lethzea rossica, ancienne période, vol. 1, sec. 2, pp. 916-917. (Described
and discussed in French.)

Siuphonotreta verrucosa (Kichwald), Scamrpr, 1861, Archiv. fiir Naturkunde Liv-, Ehst-, und Kurlands, Ist ser., Bd. 2,
p. 218. (Localities mentioned.)

Siphonotreta verrucosa (Hichwald), QuENSTEDT, 1871, Petrefactenkunde Deutschlands, Abth. 1, Bd. 2, p. 674, Pl.
LX1I, figs. 28-30. (Discussed.)

Siphonotreta verrucosa (Hichwald), QuENSTEDT, 1885, Handbuch der Petrefactenkunde, Auflage 3, p. 755, Pl. LVIII,
figs. 52 and 54. (Discussed in German.)

Siuphonotreta verrucosa (Hichwald), Gace, 1890, Beitr. zur Naturkunde Preussens, von Physikal-oekonom. Gesell.
Kénigsberg, 6, p. 22, Pl. I, figs. 2a-b. (Characterized in German.)

This beautiful and instructive species is described by de Verneuil [1845, p. 287]. Figures
5, 5a, and 5b are drawn from a specimen received from Dr. Fr.Schmidt. The outer opening of
the pedicle tube is a little longer than wide, and slightly pointed toward the minute beak, which

is at its posterior margin. There is no trace of a groove or pseudodeltidium on the false area
of this species or Suphonotreta unguiculata.

@ Localities 386y and 337m are represented in the United States National Museum collections; the other localities are taken from the
references in thesynonymy. Tne authority for each reference cited will be found in the list of localities, pp. 161-291.
b May be the type locality. Eichwald [1829, p. 274] gives it as “limestone at Reval.’’

628 CAMBRIAN BRACHIOPODA.

ForRMATION AND LOCALITY.°—Ordovician: (336w) Near Pawlowsk, near St. Petersburg, Russia.

Drift bowlders of Echinosphexrites limestone at the following localities: (386i) Near Wehlau, 30 miles (48.3 km.)
east of Konigsberg, East Prussia; (386k) near Wormditt, East Prussia; and (386 1) near Marienwerder, West Prussia;
all in Germany.

Passage beds between the Upper Cambrian and the Ordovician: (836e) Orthoceratite limestone at Pulkowa;
(337m) Orthoceratite limestone at Popowka; and (336y) glauconitic limestone at Popowka; all near St. Petersburg, Russia.

(887f) ‘‘ Vaginatenkalk”’ at Tiirsel, 15 miles (24.2 km.) west of Narwa; and (387g) “‘ Vaginatenkalk’’o at Chudleigh,
25 miles (40 km.) west of Narwa; both in the Government of Esthonia, Russia.

Genus KEYSERLINGIA Pander.¢

Orbicula pr VERNEUIL (in part) [not Lamarck], 1845, Géologie de la Russie d’Europe, by Murchison, de Verneuil,
and de Keyserling, vol. 2, pt. 3, p. 288. (Described and discussed in French. Of the species included in the
genus only “‘Orbicula buchii” is treated in this monograph.)

Not Orbicella Dana, 1846; see Scudder’s Nomenclator Zoologicus, p. 236. (Proposed for a genus of the Polypi.)

Orbicella D’ ORBIGNY (in part) [not Dana], 1850, Prodrome de Paléontologie, vol. 1, p. 20. (Characterized in French.
“Orbicella bucht” is the only one of the many species placed under the genus which is treated in this monograph.)

Keyserlingia PANDER, 1861, Bull. Acad. imp. sci. St.-Pétersbourg, tome 3, columns 46-48. (Described and discussed
in German.) .

Keyserlingia Pander, Datt, 1877, Bull. U. 8. Nat. Mus. No. 8, p. 39. (Merely listed, but gives “‘Orbicula reversa” as
the type.)

Orbicella d’ Orbigny, Dawn (in part), 1877, idem, p.50. (Cites Orbicella buchi as the type and gives synonymy of genus.)

Keyserlingia Pander, OrHLERT, 1887, Manuel de conchyliologie, by Fischer, p. 1268. (Described in French, with
figures of Keyserlingia bucht.)

Not Keyserlingia Karpinsky, 1887, Bull. Acad. imp. sci. St.-Pétersbourg, tome 31, p. 476, footnote. (The use of the
name Keyserlingia in this reference is clearly a typographical error, ‘‘ Helmersenia” being the proper term.)

Orbicella d’Orbigny, Hatt and CiarKkeE, 1892, Eleventh Ann. Rept. State Geologist New York for 1891, p. 254. (Pan-
der’s original description, 1861, p. 46, translated.)

Orbicella d’ Orbigny, Hatt and CuarKe, 1892, Forty-fifth Ann. Rept. New York State Museum for 1891, p.570. (Copy
of preceding reference.)

Keyserlingia Pander, Hatt and CLarke, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, pp. 117-119. (Copies
the translation of Pander’s original description given by Hall and Clarke, 1892a, p. 254, and discusses the genus
and the priority of the generic names proposed for it.)

Keyserlingia Pander, Watcort, 1908, Smithsonian Misc. Coll., vol. 58, No. 4, Pl. XI, and pp. 142 and 146. (Classifica-
tion of genus.)

The description of the type species, Keyserlingia buchi, gives all that is known of this genus.
My description and remarks are based on the study of a considerable number of specimens
collected for me by Mr. Schmalensee at Jaggowal, Hsthonia, and a few received from Dr. Fr.
Schmidt, collected at Kunitz, Government of Pskow.

From the means of comparison with other related generic forms it appears that Keyser-
lingia has an interior pedicle tube somewhat like that of Siphonotreta wnguiculata (Hichwald),
but that the pedicle cleft is back of the apex as in Schizotreta elliptica Kutorga. A young shell

. has a very clear opening in the pedicle cleft, but in nearly all adult shells the opening is closed.
In the interior of the ventral valve of many shells the pedicle tube extends forward into the
valve (Pl. LXXXI, fig. 4a), but in adult shells it is often closed by a vesicular growth of shell
(fig. 4b).

Keyserlingia, as exemplified by K. buchi, is a form having an external pedicle cleft back
of the apex much like that of Schizotreta, and an interior pedicle tube extending forward a
varying distance but not usually beyond the center.

Type.—Orbicula buchi de Verneuil.

The generic name was given in honor of A. de Keyserling.

YY, KEYSERLINGIA BUCHI (de Verneuil).
Plate LX XXI, figures 4, 4a-e.
Orbicula buchii DE VERNEUIL, 1845, Géologie de la Russie d’Europe, by Murchison, de Verneuil, and de Keyserling,
vol. 2, pt. 3, pp. 288-289, Pl. XIX, figs. la-c. (Described and discussed in French as a new species.)

a Localities 386y and 337m are represented in the United States National Museum collections; the other localities are taken from the
references in the synonymy. The authority for each of the localities cited will be found in the list of localities, pp. 161-291. I have been
unable to determine which js the type locality.

b The Vaginoceras limestone is the equivalent of the Orthoceratite limestone.

ce The synonomy for this genus is not complete; it includes only those references dealing with the species taken up in this monograph.

SIPHONOTRETIDA. 629

Orbicella buchi D’ORBIGNY (in part), 1850, Prodrome de Paléontologie, vol. 1, p. 20. (Changes generic reference, but

includes ‘‘Orbicula reversa” also as a synonym of ‘‘Orbicella buchi.’’) F
Discina buchit (de Verneuil), ErcHwaxp (in part), 1860, Lethzea rossica, ancienne période, vol. 1, sec. 2, p. 914.

(Described and discussed in French. Eichwald includes Jeremejew’s Siphonotreta ladogensis as a synonym.)
Keyserlingia buchi (de Verneuil), Panpmr, 1861, Bull. Acad. imp. sci. St.-Pétersbourg, tome 3, columns 46-48, Pl. IT,

figs. la-h. (Described and discussed in German.)

Orbicella buchi (de Verneuil), Hatt and Cuarxe, 1892, Eleventh Ann. Rept. State Geologist New York for 1891, p. 254,

Pl. IV, figs. 8-10. (Mentioned as the type species. Figs. 8, 9, and 10 are copied from Pander, 1861, Pl. II,

figs. la, 1h, and 1c, respectively.) k
Keyserlingia buchi (de Verneuil), Hart and CiarKe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, p.118,

Pl. IV, figs. 1-3. (Note fixing “‘K. buchi” as the type species. Figs. 1-3 are copied from Hall and Clarke,

1892a, Pl. IV, figs. 9, 10, and 8, respectively.)

Shell inequivalve, circular, or slightly oval longitudinally or transversely. Ventral valve
depressed conical with the apex from just in front of the posterior margin to one-fifth of the
length of the valve toward the front margin; a roughly outlined false area is formed by the
incurving of the posterior slope from each side beneath the apex, to a narrow cleft that extends
downward from the apex a varying distance toward the posterior margin; the narrow cleft is
usually closed at the bottom, but in some examples it has a small elongate opening midway and
in others a minute rounded opening toward the lower or posterior part. The exterior of the
dorsal valve is slightly convex with the apex marginal. Surface marked by fine, concentric
strie and a few stronger lines of growth that pass beneath the apex across the false area except
where interrupted by the pedicle cleft; when the latter is closed the striz do not cross the shell
substance at the bottom of the cleft. In addition there are faint traces of fine radiating striz
and on some ventral valves a few obscure, low, radiating ridges.

The area of the ventral valve rises from the plane of the margins of the valve at an angle
of about 45°; it is slightly arched inward at the center, and is marked by strong strie of growth
parallel to the outer margin. Within the valve a median ridge of varying strength and length
extends forward from the front margin of the area. In fifteen examples it is less than one-half
the distance to the front margin, and in only one it extends forward beyond the center. On all
unbroken specimens a strong projection extends upward from the median ridge just in advance
of the area; it is narrow at the base, widening sideways and backward; it has a large variously
shaped anterior opening that narrows toward the base of the projection; the size of the projec-
tion and opening depends upon the amount of shelly matter that has been deposited on and in it.
The opening is the inner end of the pedicle tube; in some examples it is entirely filled with
-shelly deposit (Pl. LX XXI, fig. 4b), and in others it is still open; in several examples with an
open interior aperture the pedicle cleft is closed at the exterior end. The median ridge, in front
of the pedicle tube, has a vesicular interior that gives it a hollow appearance when the top is
broken away. In several examples the pedicle muscle scar is clearly preserved, on the projec-
tion from the median ridge, just in front of the opening of the pedicle tube. On each side of
the median ridge close to the area the cardinal muscle scars are either in a depressed pit or on a
more or less elevated projecting growth of shell rising from the bottom of the valve; sometimes
the projections extend beyond the plane of the margins of the valve (Pl. LX XXI, fig. 4c), and
often the central projection about the pedicle tube extends above the plane of the margin. On
some shells the area indicated as the cardinal scar shows the points of attachment of three
muscles, probably the umbonal, transmedian, and anterior laterals; the only indication of the
points of attachment of the muscles corresponding to the central, outside, and middle laterals
of Obolus is on the sides and beside the elevated pedicle tube.

The area of the dorsal valve has a broad, triangular, slightly concave space at the center
that is bounded by narrow flexure lines; on each outer side of the flexure line the area narrows
and slopes upward at an angle of about 30° to 45°; it is marked by distinct lines of growth that
cross the central depressed space subparallel to the margin of the area. Within the valve a
strong median septum extends from the area to the front part of the valve; this septum when
broken shows an interior vesicular structure that gives the appearance of its having been hollow.
Well toward the front an oval muscle scar (central) occurs on each side of the septum; the car-

_dinal muscle sears are oval in outline close to the area and surrounded by a more or less thickened

630 CAMBRIAN BRACHIOPODA. ~

shell growth in old shells. Between the large cardinal scars and the outer margin there is a
narrow, elongate, depressed area in which the outside and middle lateral muscles may have been
attached. : .

Shell substance corneous. The shell is built up of numerous thin layers or lamellae, and
the thick growth of the old shells is by irregular accretions. The average size of the shells is
5 to 7 mm. in diameter.

Observations.—This interesting form was evidently in its younger stages a siphonate shell
that had its pedicle tube closed by shell growth in the adult stage. I have broken several
ventral valves on the line of the pedicle cleft and found that the shell within the cleft has a
vesicular structure and that the opening could not be traced through the shell. The filling
up of the pedicle tube and the deposition of shelly matter about the interior opening of the
tube appear to have been a phase of adult growth and old age. The filling of the tube must
have cut off the pedicle and left the shell to drift about very much as in the case of Leptena
rhomboidalis and Rhynchotrema capazx [Hall and Clarke, 1894, p. 184].

This species differs from Orbicula reversa de Verneuil [1845, p. 289] in having the apex of
the ventral valve much nearer the posterior margin.

FORMATION AND LOCALITY.—Upper Cambrian : (395) Obolus sandstone at Joa, near Jegelecht, 12 miles(19.3 km.)
east of Reval, Government of Esthonia; (395b) Obolus sandstone at Ilgast, Government of Esthonia; (9d) Obolus
sandstone at Jacgowal, about 20 miles (32.2 km.) east-southeast of Reval, Government of Esthonia; (336n [de Verneuil,
1845, p. 289]) on Tjora (Ischora) River, Government of St. Petersburg; (3360) Ungulite grit, Koporje, Government of St.

Petersburg; (336a [Eichwald, 1860, p. 914]) Obolus sandstone at Podolova (Putalova?) on Ijora (Ischora) River,
Government of St. Petersburg; and (336p) Ungulite grit, Kunitz, Government of Pskow; all in Russia.

Superfamily ACROTRETACHA Schuchert.

Family ACROTRETID Schuchert.
Subfamily ACROTHELIN® Walcott and Schuchert.

Genus ACROTHELE Linnarsson. 2
[dxpoc, at the top; and 4A, nipple.)

Acrothele LinNarsson, 1876, Bihang till K. svensk. Vet.-Akad. Handl., Bd. 3, No. 12, pp. 20-21. (Described and
discussed in English as a new genus.)
Acrothele Linnarsson, Zirren, 1880, Handbuch der Palzontologie, Bd. 1, Abth. 1, p. 665. (Described in German.)

aThe synonymy for this genus does not give a complete record of the various genera under which the species now included in Acrothele were
formerly placed; it gives only those references in which the genus is discussed or described. To complete the record the following mere generic
references are listed:

Discina (Orbicula) de Verneuil and Barrande [1860.
p. 532).

Obolella Billings [1862d, p. 68; 1863, p. 230}.

Obolella Chapman [1863, p. 191; 1864, p. 163).

Obolella Salter [1866, p. 285].

Obolclia Davidson [1868, p. 311].

Lingula Hartt [1868, p. 644].

Obolella Davidson [1871, p. 341].

Obolella Ford [1873, p. 213).

Acrotreta ? White [1874, p. 6; 1877, p. 34].

Acrothele Brogger [1878, p. 76].

Lingula Hartt [1878, p. 644].

Acrothele 1.innarsson [1879, p. 25].

Obolus ? Barrande [1879b, Pl. CII: vu).

Acrothele White [1880, p. 41].

Discina (Acrotreta?) Brogger [1882, p. 47).

Acrothele ? Walcott [1884b, p. 14].

Acrothele Walcott [1884b, p. 15).

Billingsia Ford [1886a, p. 467).

Elkania Yord [1886b, p. 325).

Acrothele Matthew [1886, pp. 39 and 43).

Acrotreta Walcott [1886b, pp. 107, 108, and 109).

Obolella ? Walcott [1886b, p. 111).

Obolella Walcott [1886b, p. 118}.

Acrothele Beecher [1891, Pl. XVII, fig. 12}.

Lingula Hartt [1891, p. 644].

Acrothele Walcott [1891a, pp. 608 and 609).

Obolella Walcott [1891a, p. 612).

Obolella Hall and Clarke [1892c, p. 70].

Acrotreta Hall and Clarke [1892c, pp. 100 and 103).

Acrothele Moberg [1892b, p. 114].

Discina Miquel [1893, p. 9; 1894a, p. 106; 1894b, p.
10; 1895, p. 10).

Acrothele Matthew [1895a, p. 128, Pl. V, figs. 7a-b,
and Pl. V, figs. 8a-b].

Acrothele Pompeckj [1896b, pp. 509-511 and 603).

Acrothele Matthew [1897, p. 168). _

Linnarssonia Schuchert [1897, p. 262].

Acrothele Walcott [1897b, p. 716; 1898b, p. 402].

Obolella Hobbs [1899, p. 114].

Acrothele Matthew [1899b, p. 202].

Acrothele Grabau [1900, p. 615).

Linnarssonia ? Walcott [1901, p. 673).

Acrothele Grénwall [1902, pp. 39 and 40).

Acrothele Matthew [1902b, pp. 396, 397, 398, 400, and
402; 1902c, p. 110).

Acrothele Walcott [1902, p. 598}.

Obolella Delgado |1904, p. 364).

Acrothele Delgado [1904, p. 365).

Acrothele ? Walcott [1905a, p. 303].

Acrothele Walcott [1905b, p. 11).

Acrothele Moberg and Segerberg [1906, p. 67].

Acrothcle Shimer [1907, pp. 176 and 177).

Obolellia Grabau and Shimer [1907, p. 189].

Acrothele Walcott |1908d, pp. 82-88].

a

ACROTRETIDZ. 631

Acrothele Linnarsson, Davipson, 1883, British Fossil Brachiopoda, vol. 5, pt. 2, pp. 213-214. (Copies description

given by Linnarsson, 1876, p. 20.)

Acrothele Linnarsson, WaucorTtT, 1886, Bull. U. 8. Geol. Survey No. 30, pp. 107-108. (Copies original description
[Linnarsson, 1876, p. 20] and discusses genus.)

Acrothele Linnarsson, OEHLERT, 1887, Manuel de conchyliologie, by Fischer, pp. 1269-1270. (Described in French.)

Acrothele Linnarsson, Hatt and CLarKeE, 1892, Eleventh Ann. Rept. State Geologist New York for 1891, pp. 249-250.
Described.

Tie eee Hatt and CrarKe, 1892, Forty-fiith Ann. Rept. New York State Museum for 1891, pp. 565-566.

(Copy of preceding reference.)

Acrothele Linnarsson, Haut and CLARKE, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt.1, pp. 98-101. (Copies
original description, Linnarsson, 1876, p. 20, and discusses genus.)

Acrothele Linnarsson, MatrHEw, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, pp. 103-105. (Dis-
tribution discussed and tabulated.)

Acrothele Linnarsson, GRABAU and SuimER, 1907, North American Index Fossils, vol. 1, p. 200. (Described.)

Linnarssonia GRABAU and SHIMER?, 1907, idem, p. 200. (Described, but the only species referred to the genus (Lin-
narssonia pretiosa) is not figured, and it is impossible to tell whether the authors are discussing the L. pretiosa
that is now referred to the genus Acrotreta (Acrotreta sagittalis), or to the genus Acrothele (Acrothele pretiosa).)

Acrothele Linnarsson, Watcott, 1908, Smithsonian Misc. Coll., vol. 53, No. 4, Pl. XI, and pp. 142 and 146. (Classi-
fication of genus.) :

General form subcircular to transversely broad oval in outline. Ventral valve moderately
convex to subconical; a false area is usually more or less distinctly outlined on the ventral
‘valve between the apex (beak) and the posterior margin; pedicle opening on the posterior
slope of the apex (or beneath the beak). The only suggestion of a true cardinal area is in
Acrothele bellula Walcott (Pl. LVIII, fig. 5c); and this appears to be a broadening and slight
flattening of the posterior under edge of the shell. Dorsal valve gently convex, and some-
times nearly flat; beak minute, marginal; area known only in A. bellula Walcott (Pl. LVIII,
figs. 5{-h), where it is short and divided midway by a small, triangular false deltidium, very
much as in Acrotreta definita Walcott (Pl. LXIV, fig. 2d.)

Surface marked by concentric lines and striz of growth which cross the false area of the
ventral valve; on some species there are low, rounded, radiating ridges that are usually con-
fined to the ventral valve; in addition, on some species, there is a series of more or less inoscu-
lating, irregular, fine ridges with tubercles on them, which gives a highly ornamented surface
such as occurs on some forms of Micromitra and Westonia.

The shells of Acrothele rarely exceed 13 mm. in diameter, and the average size of adult
shells is from 6 to 8 mm. Substance of shell corneous. ‘The shell is built up of several layers
or lamellz that are usually more or less obliquely inclined to the outer surface, over the central
and outer portions.

The interior of the ventral valve has a small visceral area about the pedicle opening and
extending a short distance in front of it; in several species an elongate depression occurs on
each side and a little in advance of the pedicle opening that corresponds to the tubercle on
each side of the apex of the outer surface; frequently the shell is thickened beneath the visceral
cavity and a short ridge of varying width and length results; the edge of the pedicle opening
may be slightly thickened, which forms a callosity or apical swelling, but not to the same
extent as in the ventral valve of Acrotreta. Nothing has been seen of an area in front of the
visceral area corresponding to the trapezoidal areas of Obolus, Acrotreta, and Trematobolus, in
which the central, outside lateral, and middle lateral muscles were attached; in fact, it is only very
rarely that the impression of the visceral area is shown. The main vascular sinuses start
from just back of the pedicle opening, and curve, one on each side, out and then forward into
the body of the valve, usually within a line drawn halfway between the center and the outer
margin of the valve; many branches from the main sinus occur in some species. The trans-
median and anterior lateral muscle scars appear to be merged in the cardinal muscle scar, situ-
ated on the outer posterolateral slope, outside of the main vascular sinuses; on one shell what
appear to be the umbonal muscle scars are preserved (Pl. LXI, fig. 1c).

The interior of the dorsal valve has a median ridge of varying length and size, and main
vascular sinuses that start near the posterior margin and extend directly outward for a short
distance, and then obliquely forward in almost a direct line (Pl. LVI, figs. 1d and le; Pl. LX,
figs. 1kand11). The cardinal muscle scars are usually small and close to the posterolateral

632 CAMBRIAN BRACHIOPODA.

margin (Pl. LX, fig. 1k), but larger scars occur and extend farther forward into the valve (PI.
LXII, fig. 1f; Pl. LVII, figs. 3c, 3d, and 5h). The central and anterior lateral scars are
situated essentially as in Obolus; the former on the slopes of the median ridge and the latter
at the anterior end of the ridge.

Type.—Acrothele corvacea Linnarsson.

Observations.—The generic description is drawn up from the material studied in connec-
tion with the various species now referred to the genus. One of Linnarsson’s species, Acrothele
granulata [1876, p. 24] I have taken as the type of the subgenus Redlichella on account of the
differences in the interiors of the valves.

Surface characters—The surface characters of the various species of Acrothele vary nearly
as much as those of Micromitra. The species may be grouped by the surface features under
three headings: (1) Striato-granulose; (2) concentrically ridged, striated, or nearly smooth;
(8) pseudopunctate.

The first group, striato-granulose or radulo-granulose, includes, as now known, sixteen
species and seven varieties. The surface of the type species of the genus, Acrothele coriacea
Linnarsson, is representative of this form of surface. It has concentric lines of growth, and
a series of concentric, irregular, more or less inosculating, rounded, fine ridges upon which
minute nodes or granules occur; these granules, on some species, are more or less regularly
arranged on the ridges and appear over nearly the entire surface (Pl. LVI, fig. 1g), while in
others they are scattered irregularly (Pl. LXI, fig. 4d). On Acrothele matthewi (Hartt) (Pl.
LXI) and some other species the younger shells are granulated, while on the older shells the
ridges are fairly regular and only an occasional granule occurs on them. On most adult shells
with this form of surface the ridges near the margin are more regular and rarely inosculate.
This type of surface occurs also on Acrothele (Redlichella) granulata (Linnarsson) (Pl. LVI,
fig. 2g) and Botsfordia granulata (Redlich) (Pl. LVII, fig. 4r) and Botsfordia czlata (Hall)
(Pl. LIX, figs. 1h and 1o).

The species upon which I have seen the ridges and granules are:

Acrothele avia Matthew. Acrothele panderi Walcott.
avia puteis Matthew. pretiosa (Billings).
bergeroni Walcott. prima (Matthew).
colleni Walcott. prima costata (Matthew).
coriacea Linnarsson. proles Matthew.
decipiens Walcott. quadrilineata Pompeckj.
gamagei (Hobbs). spurri Walcott.
intermedia Linnarsson. : subsidua (White).
matthewi (Hartt). subsidua hera Walcott.
matthewi eryx Walcott. subsidua levis Walcott.

- matthewi lata Matthew. ; yorkensis Walcott.

matthewi multicostata Matthew.

Acrothele bellula Walcott has this type of surface, but the ridges and granules are so minute
that they are only to be seen with a very strong lens.

The second group is concentrically ridged, striated, or smooth, as far as known. I think,
however, that with better-preserved specimens some of the species now included under it would
be found to have the striato-granulose surface.

The species referred to it are:

Acrothele bohemica (Barrande). Acrothele? minuta Walcott.
borgholmensis Walcott. Acrothele nitida (Ford).
ceratopygarum (Brégger). / turneri Walcott.
levisensis Walcott. woodworthi Walcott.

maculata (Salter).
On the pseudopunctate surface the union of the inosculating ridges is very regular

and the hollows or pits between the ridges are arranged in oblique lines that appear to start
on the posterolateral margins of the valves and curve obliquely forward to the opposite

Se

ACROTRETID”®. 633

side (PI. LVII, fig. 3b). Itis the same type of surface as that of Botsfordia pulchra (Matthew)
(PI. LXII, figs. 5, 5a-c) and Micromitra ([phidella) pannula (White) (Pl. IV, figs. 1t and 1s).
This form of surface is represented by only one species: Acrothele bellapunctata Walcott
(Pl. LVII, figs. 3, 3a—b).

The surface of the following species has not been definitely determined owing to the condi-
tion of preservation. I think most of them will be found to belong to the group represented
by A. corvacea Linnarsson (p. 642):

Acrothele dichotoma Walcott.
pr.imeeva (de Verneuil and Barrande).
rara Walcoit.
villaboimensis Delgado.
sp. undt. a Walcott.
sp. undt. Moberg.

The group of forms described by G. F. Matthew [1903, pp. 98-103] from the ‘‘Etcheminian”
of Nova Scotia, and A. prima (Matthew) [1886, p. 41] from New Brunswick, and A. prima
costata (Matthew) [1895a, p. 128], are all closely related by their general form, usually strong shells,
and surface characters; the latter are variable but the range of variation is usually to be found
on any large, old shell, an exception being found in radiating ridges, which vary greatly and to a
certain extent depend upon conditions that affected the shell after the animal died, such as
maceration and distortion by compression and movement in the embedding sediment. The
shells above the horizon of the Paradoxides zone, represented by Acrothele matthewi (Hartt),
appear to have been affected also DY, the same conditions: although the sediment is usually
finer and more compact.

Pompeckj [1896b, p. 603] toners that the shell described - de Verneuil and Barrande
[1860, pp. 536-537] was probably a species of Acrothele, and probably the same as the shell
collected by Miquel. My study of Miquel’s material shows that a true Acrothele is repre-
sented: A. bergeront Walcott (Pl. LVIII, figs. 6, 6a-c). The other form is biconvex, calcareous,
and not a typical Acrothele. I have referred to it provisionally (p. 602) as Botsfordia? barrandet.

Comparisons with other genera.—The relations between Acrothele and Acrotreta were recog- °
nized by Linnarsson [1876, p. 20] and by all subsequent authors who have had occasion to
discuss the genus. Both genera have (a) a more or less elevated ventral valve with a pedicle
opening at the summit of a more or less distinctly defined false area; (b) a moderately convex
dorsal valve with somewhat similar interior markings; (c) small visceral areas in the ventral
valve; (d) corneous shells built up of thin layers.

Acrothele differs from Acrotreta (a) in having a depressed ventral valve; (b) a faintly defined
false area in the ventral valve; (c) larger size; (d) greater variety and more highly ornamented
surface; (e) apparently more complex vascular markings; and (f) a difference in the position
of the main vascular sinuses; for the dorsal valve this is best seen by comparing Plate LX, figures
1k and 11, Acrothele subsidua (White), with Plate LXV, figures 1f and 1g. I have examined
many hundred specimens of the interior of dorsal valves of Acrotreta without finding any traces of
the main vascular sinus, whereas in Acrothele they are usually present. In the ventral valve the
differences are also marked, as the vascular sinuses are proportionally much larger in Acrotreta.

There are exceptions to the marked difference in elevation of the ventral valve, as that
of Acrothele subsidua (White) (Pl. LX, figs. 1a, 1c, and 1d) is nearly as elevated as that of
Acrotreta saguttalis taconica (Walcott) (Pl. LXXI, figs. 1, la-e).

Acrotreta appears to be a somewhat more highly delevoped form than Acrothele, although
a smaller shell.

Geographic distribution.—Species of the Acrothele coriacea type occur in Sweden, Denmark,
Bohemia, southern France, and Portugal in Europe; in eastern North America, in Nova Scotia
and New Brunswick; in western North America in Utah, Nevada, Idaho, and Montana. This
indicates the wide distribution of one specific type, and other forms extend the distribution

634 CAMBRIAN BRACHIOPODA.

far to the south in the Appalachian province, A. bellula Walcott; and to the north in Pennsyl-
vania, A. yorkensis Walcott. The general distribution of species is given in the table (p. 105)
and the details of each species under the specific description.

Stratigraphic range.—Acrothele is represented by eight species and one variety in the
upper portion of the Lower Cambrian in association with Olenellus or allied forms of trilobites,
but in no instance has it been found low down in the Lower Cambrian. In the Middle Cambrian
twenty-one species and six varieties occur, and there the genus attained its widest distribution
and greatest development. One species, A. borgholmensis Walcott, occurs in strata of the
Ceratopyge zone, and three species in Lower Ordovician formations. Of the latter, A. ceratopy-
garum is not a typical form of Acrothele. (See p. 640.)

ACROTHELE ARTEMIS Walcott.
Text figure 54. +

Acrothele artemis Waxcott, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, p. 82, Pl. VIII, fig. 10. (Described and
discussed as below as a new species. Fig. 10 is copied in this monograph as fig. 54.)

General form of ventral valve moderately convex; subcircular and somewhat obtusely
acuminate in outline; apex near the posterior margin; pedicle opening unknown, but from the
occurrence of a small boss on the inside of the shell beneath the
apex it was probably of the same character as in closely related
species.

Surface marked by concentric lines and small ridges of growth,
and an irregular system of fine granules on the concentric ridges;
in the lower interspaces there is an irregular distribution of very
minute inosculating ridges that, with the tubercles, form a surface
independent of the concentric growth lines. The shell is built up
Figure 54.—Acrothele artemis Walcott. of numerous lamelle beneath the outer surface layer and appears

A, A’, Ventral valve with the apex 4
proken. Thespecimen isfrom Lo. to have been corneous, or composed of phosphate of lime and

cality 5b, Middle Cambrian lime- @hjtin.

stones in Twomile Canyon, south- E
cost OF Meinda, Onis Canitiy, The largest shell has a length and width of 10 mm.; the apex

Idaho. (U.S. Nat. Mus. Cat. No. js about 2 mm. from the posterior margin; dorsal valve unknown.
51969.) The figure is copied from a gel . . 1 2 =

Walcott, 19084, Pl. VIII, fig. 10. Observations.—This species resembles in form Acrothele prima

costata (Matthew) (Pl. LXI, figs. 4 and 4a), and both species have

a granular surface. The latter species, however, has a thinner shell, and its surface is marked

by much larger granules. I know of no other closely related species.

ForMATION AND LOCALITY.—Middle Cambrian: (5b) Dark blue-gray Langston limestone [Walcott, 1908f, p. 198],
just above the Cambrian quartzitic sandstones, north side of Twomile Canyon, near its mouth, 2 miles (3.2 km.) south-
east of Malade, Oneida County, Idaho.

; ACROTHELE AvIA Matthew.

Plate LXI, figures 7, 7a—b; Plate LXII, figures 1, la—k.

Acrothele avia MartHEw, 1899, Bull. Nat. Hist. Soc. New Brunswick, vol. 4, pt. 3, No. 18, pp. 202-203, Pl. III, figs.
ja-h. (Described as a new species. The specimens represented by figs. 1c and 1f are redrawn in this mono-
graph, Pl. LXI, figs. 7a and 7b, respectively.)

Acrothele avia Marturw, 1902, idem, pt. 5, No. 20, pp. 396-398, Pl. XVI, figs. 7a—b; Pl. XVII, figs. la-f and 2a-b.
(Described and discussed. Pl. XVII, figs. laf, and Pl. XVI, figs. 7a—b, are copied from Matthew, 1899b, PI.
III, figs. lah. The specimens represented by figs. 2a and 2b are redrawn in this monograph, Pl. LXI, fig. 7,
and Pl. LXII, fig. li, respectively.) :

Acrothele abavia MarruEw, 1902, idem, pp. 398-400, Pl. XVI, figs. 3a-d and 4a-b. (Described and discussed as a new
species.)

Acrothele avia MartHEw, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, p. 55. (Notes on orienta-
tion of valves.)

ACROTRETIDZ. 635

Acrothele avia MattHEW, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, pp. 98-99, Pl. V, figs.
la-f and 2a—b. (Described and discussed essentially as in Matthew, 1902a, pp. 396-398. Figs. la-f are copied
from Matthew, 1899b, Pl. III, figs. la-f; figs. 2a and 2b are copied from Matthew, 1902a, Pl. XVII, figs. 2a and
2b, respectively.)

Acrothele abavia MattHEw, 1903, idem, pp. 100-101, Pl. IV, figs. 3a-d and 4a—b. (Described and discussed as in
Matthew, 1902a, pp. 398-400. Figs. 3a-d and 4a-b are copied from Matthew, 1902a, Pl. XVI, figs. 3a-d and
4a—-b, respectively.)

This is a strong shell of the Acrothele matthewt (Hartt) type. The adult shells are some-
what thicker, the surface is a little different, being coarser, and the callosity in front of the
pedicle opening is longer and larger than in A. matthewi or its varieties. Matthew [1902a,
p- 396] gives as one of the most marked distinctions of this species the presence on the sides
of the dorsal valve of ‘‘about a dozen radiating, branching, crenulated ridges that extend
to the margin.” With all of Matthew’s types before me, I find one bit of rock with two ventral
valves, one partly overlapping the other; on these the radiating ridges not only occur on the
sides, but also over the middle of the shell, and where a bit of the shell is broken off the ridges
are clearly impressed on the cast of the interior; this specimen is labeled as one of the original
types of the species; a second ventral valve preserving a part of the exterior surface also shows
traces of radiating ridges. Another type specimen shows part of the exterior surface and
the cast of the interior, but there is no trace of a radiating ridge on the outer surface or cast;
seven specimens of the dorsal valve on which the outer layer is exfoliated show no traces of
the radiating ridges. I find further that the dorsal valves on which the radiating ridges occur
are very thin and hence liable to be flexed by lateral pressure, developing surface ridges on
the lines of radiating strie that occur on the inner layers of nearly all shells of Acrothele. On
the ventral valve a few radiating ridges occur on one of the specimens (Pl. LXJ, fig. 7); another
specimen, laterally compressed, shows many such ridges (Pl. LXI, fig. 7a). Other specimens
are without exterior traces of ridges, but when the shell is exfoliated, numerous fine, radiating
strie with stronger and deeper striz at wider intervals are to be seen. I have taken up this
matter of the radiating ridges at length, as I do not consider the side ridges on the dorsal valve
of Acrothele avia sufficient to separate it from other species to which it is closely related.

The surface is formed of fine, irregular, concentric, rounded ridges that frequently inoscu-
late; these ridges are crenulated by fine depressions which cross them and thus outline tubercles
or rounded points of varying height and size, depending upon the depth of the radiating cross
depressions; this type of surface gives great variety to different parts of the shell and to dif-
ferent shells. As far as I can determine by the use of a strong lens (three-quarter inch) it
is essentially the same type of surface as that occurring on Acrothele matthewi (Hartt) and
related species, one of which is shown by Plate LXI, figure 4d.

At the apex of one of the specimens of the ventral valve in Matthew’s collection there
are two minute elongate tubercles with a narrow depression between them, and on the pos-
terior slope there is an oval pedicle opening with the narrow end nearest the apex; a low,
narrow ridge, that divides the obscure false area midway, extends from the opening to the
posterior margin.

“*Acrothele abavia” Matthew does not appear to vary specifically from the forms of
Acrothele avia in which the radiating ridges are absent. The specimens occur in a little coarser
sediment, and on this account are not well preserved. Matthew [1902a, p. 399] speaks of a
small tubercle in front of the pedicle opening and “‘the visceral callus that extends half of
the length of the shell” of the ventral valve; such a tubercle occurs on the only two specimens
of A. avia well enough preserved to show the interior of the ventral valve. I do not find the
elongate visceral callus on any specimens of the ventral valve in Matthew’s collection; some
specimens do show a short callosity similar to that in A. avia. After a very careful study
of all the specimens, also of a large collection from the same locality and strata belonging to
the United States National Museum, I am led to think that Matthew mistook the median
ridge of some dorsal valve in which the posterior portion was broken away as the visceral
callosity of the interior of a ventral valve; this belief is further strengthened by his statement
[1902a, p. 399]: ‘‘On each side of the callus a groove runs out toward the front margin. Some

636 CAMBRIAN BRACHIOPODA.

examples show a median and two lateral septa in front of the callus.” (See interior of dorsal
valve as shown by Pl. LXII, fig. ig.) In the United States National Museum collection, from
Matthew’s horizon E3a, I find 13 interiors of the ventral valve with short ‘‘callus” and 10
typical exteriors, also 22 dorsal valves. There are also fair specimens from horizons 3d and
3e. The shells of horizon 3a have the oblate form of Acrothele avia found at horizons 3d and 3e.

Acrothele avia differs from Acrothele proles Matthew in having the apex of the ventral
valve a little nearer the posterior margin, but not so near as that of Acrothele prima (Matthew).

ForMATION AND LOCALITY.—Middle Cambrian: (13d/’) Sandstones 10 feet (3 m.) below Division H2a; (18d and
13d’) sandstones opposite the third waterfall in Dugald Brook, between Divisions H2a and 2b; (10p) sandstone just
below the waterfall in Division E2b; (131 and 131’) sandstones of Division H3a; (844 [Matthew, 1903, p. 81]) sandy
shales of Division E3b; (44a [Matthew, 1903, p. 26]) sandy shales of Division E3c; (344b [Matthew, 1903, p. 81])
sandy shales of Division H3d; (18n’)¢ sandstones of Division He; and (18n) sandstones of Division W3t; all in Mat-
thew’s [1903, p. 21] Etcheminian, on Dugald Brook, Indian River, eastern Cape Breton, Nova Scotia.

(18m) Sandstones of Division H3f of Matthew’s [1903, p. 76] Etcheminian, on Gillis Brook, Indian River, and
(10p’”) sandstone on the small brook on the hill between the bridge over Indian River and McPhees Brook; both in
eastern Cape Breton, Nova Scotia.

ACROTHELE AVIA PUTEIS Matthew.

Acrothele avia-puteis MarrHew, 1902, Bull. Nat. Hist. Soc. New Brunswick, vol. 4, pt. 5, No. 20, p. 398, Pl. XVI,
figs. 5a-b. (Characterized as a new variety.)

Acrothele avia-puteis MartHEew, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, p. 100, Pl. IV, figs.
5a-b. (Characterization and figures copied from preceding reference.)

This seems to be a variety of Acrothele avia Matthew. It differs in the possession of a pair
of pits, one of which lies on each side of the space between the foramen and the visceral callus,
partly overlapping each. The visceral callus is quite short in this form and has but little promi-
nence. The ridges on the surface of the shell are more regularly concentric than in the type,
and more sharply cut; about ten are found in the space of 1 millimeter. The cardinal area is
curved forward toward the top, and finely striated. The foramen is about a fifth of the length
of the valve from the cardinal line, and the front of the callus about a third. Vascular trunks
and branches are visible on the surface of the ventral valve as in A. avia. The dorsal valve
does not sensibly differ from that of A. ama.

The largest valve seen was 8 mm. long and about the same width.

The typical specimens of the ventral valve of Acrothele ama puteis are slightly different from
those of Acrothele avia, but not sufficiently so to show clearly in an illustration. The pits
beside the median line, between the pedicle aperture and the visceral callosity, do not appear
in the specimens of the species, and indeed the condition of the material is such that probably
they could not be distinguished if originally present. The visceral callosity is shorter and
much like that of Acrothele matthewi (Hartt).

FoRMATION AND LOCALITY.—Middle Cambrian: (13m) Sandstones of Division E3f of Matthew’s [1903, p. 76]

Etcheminian, on Gillis Brook; and (344¢ [ Matthew, 1903, p. 100]) sandy shales of Division E3d of Matthew's Htche-
minian, on Gregwa Brook, both in the Indian River valley, eastern Cape Breton, Nova Scotia.

AOROTHELE BELLAPUNCTATA Walcott.
Plate LVII, figures 3, 3a-b.

Acrothele bellapunctata Waxcort, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, pp. 82-83, Pl. VIII, figs. 9 and 97.
(Described and discussed as below as a new species. Figs. 9 and 9/ are copied in this monograph, Pl. LVII,
figs. 3 and 3b, respectively.)

General form a broad transverse oval with the posterior side slightly flattened and arched
upward for a short distance below the apex. Ventral valve convex near the umbo and nearly
flat over the anterior portion of the valve; apex near the posterior margin. Foraminal aper-
ture apparently at the apex above a short, not distinctly marked, false area. Ventral valve
nearly flat and with the posterior margin curved downward so as to fill the space caused by

a18n’ is the type locality, though the specimens in the United States National Museum collections to which that number is assigned were
collected later than the type specimens.

EEE eee

ACROTRETIDA. 637

the upward arching of the margin of the ventral valve. Surface of shell beautifully ornamented
by elevated sharp oblique lines with deep interspaces that give a strongly punctate appear-
ance to the shell; concentric undulations and ridges of growth also occur in a more or less
irregular manner. The inner layers or lamelle are marked by fine, concentric, and rather
strong radiating lines. The shell is built up of numerous thin layers or lamellz of a corneous
appearance.

A slightly compressed ventral valve has a length of 5 mm. with a width of 6.5 mm. A
ventral valve is 4 mm. in length with a width of 5 mm.

Observations.—This is one of the most beautifully ornamented species of the genus. Its
surface is not unlike that of some varieties of Micromitra ([phidella) pannula (White). In
form it suggests Acrothele (Redlichella) granulata (Linnarsson). Nothing is known of the
interior character of the valves.

FORMATION AND LOCALITY.—Lower Cambrian: (8v) Shales in upper portion of Holmia kyjerulfi zone, Ringsaker,
Province of Hedemarken, Norway.

ACROTHELE BELLULA Walcott.

J

Plate LVIII, figures 5, 5a—h.

Acrothele bellula Watcort, 1897, Proc. U. S. Nat. Mus., vol. 19, pp. 716-717, Pl. LX, figs. 4, 4a-e. (Described and
discussed as a new species. Figs. 4, 4a—e are reproduced (with slight changes) in this monograph, Pl. LVIII,
figs. 5, 5a, 5c, 5fh, respectively.)

General form transversely broad oval, with the posterior margin slightly transverse.
Ventral valve slightly conical with the apex between the posterior seventh and eighth of the
length of the valve; the slope from the apex to the posterior margin is about 45° and to the
front at a low angle after passing from the steeper slope adjoining the apex. On each side
of the apex there is an elongate, sharp tubercle, and just back, a minute pedicle opening. A
shghtly outlined triangular false area begins at the pedicle opening and extends to the posterior
margin; it is divided by a faint, narrow, rounded ridge. Dorsal valve moderately convex, with
the umbo broad, and beak at the posterior margin.

The exterior surface is marked by concentric lines of growth that cross the area of the
ventral valve. The ventral valve has numerous low, narrow, obscure radiating ridges, and
an extremely minute series of irregular, concentric, inosculating elevated lines that give the
surface a roughened appearance under a strong lens.

Substance of the shell in appearance corneous. The largest shell in the collection is repre-
sented by a dorsal valve; this has a length of 6 mm.; width, 7 mm.

The casts of the interior of the ventral valve are very good; they show that the shell was
thick over the umbo, that the cast of the pedicle opening was cone-shaped (PI. LVIII, fig.
5b), and that on each side just in front of the base of the opening there was a short, narrow
depression corresponding in position to the tubercles on the outer surface. Back of the cast of
the opening the false area is rather strongly defined, also the cast of the hollows occupied by the
cardinal muscles; the main vascular sinuses originate just back of the pedicle opening and arch
forward toward the anterolateral margins of the shell (Pl. LVIII, fig. 5e); usually they have
left no impression on the shell in advance of the visceral area; the visceral area is short and
fairly well defined on some specimens (fig. 5d). Nothing is known of the muscle scars of the
ventral valve except the position of the cardinal scars.

The cast of the interior of the dorsal valve is most interesting, as a true area similar to that
of Acrotreta definita Walcott (Pl. LXIV, fig. 2d) and Acrotreta kutorgai Walcott (Pl. LXV, fig. 3j)
is clearly shown; the area is short and divided midway by a triangular space, the lateral,
slightly elevated sides of which project a little into the valve beyond the front margin, very
much as in Obolella atlantica Walcott (Pl. LV, fig. le) and O. crassa (Hall) (Pl. LIV, fig. 2¢).
A median ridge extends from in front of the area to the anterior third of the valve; it has a
narrow, low, median septum on its posterior half, and two central muscle scars (h) on its outer
slopes a little back of the center of the valve; the anterior lateral muscle scars (j) are a little in

638 CAMBRIAN BRACHIOPODA.

advance of the centrals, close to the median ridge and smaller than the centrals; the main:

vascular sinuses are very faint beyond where they come forward into the body of the valve;
back toward the posterolateral margin of the valve small cardinal scars occur at about the same
distance from the center of the area as the central scars are in front of it.

Observations.—This species is so strongly marked in its ventral valve by the pointed tuber-
cles beside the apex, the cone-shaped pedicle passage through the shell, and distinet visceral
area, and in the dorsal valve by a well-defined area and small cardial muscle scars far out
on the cardinal slope, that it can not readily be confused with any known species.

FoRMATION AND LOCALITY.—Middle Cambrian: (94x) Shales 0.06 mile (0.1 km.) south of Givens Mill, Cowan

Creek, about 8 miles (12.8 km.) southeast of Center; and (90x) im and attached to the outer surface of siliceous nodules
in the Conasauga (‘‘ Coosa”) shale, Coosa Valley, east of Center; both in Cherokee County, Alabama.

ACROTHELE BERGERONI Walcott.

Plate LVIII, figures 6, 6a-c.

La Discina MiquEt, 1893, Note sur la Géologie des Terrains Primaires du Département de l’Hérault, St. Chinian a.

Coulouma, p.9. (Mentioned in French.)
‘La Discina Miquet, 1894, Bull. Soc. d’Etude Sci. Nat. Béziers for 1898, Mém. Compt. Rend. des Séances, vol. 16,
1894, p. 106. (This article is a copy of the preceding reference which was published as a separate.)

La Discina Miquet, 1894, Note sur la Géologie des Terrains Primaires du Département de 1’Hérault, le Cambrien et.

V’Arenig, p. 10. (Mentioned in French.)

La Discina Mrquet, 1895, Bull. Soc. d’Etude Sci. Nat. Béziers for 1894, Mém. Compt. Rend. des Séances, vol. 17,
1895, p. 10. (This article is a copy of the preceding reference which was published as a separate.)

Acrothele PompxEcxs (in part), 1896, Jahrb. K.-k. geol. Reichsanstalt for 1895, Bd. 45, Hit. 3, p. 603. (Discussed in
German, changing generic reference; see under Botsfordia? barrandei, p. 603, for copy.)

Acrothele bergeroni Waxtcort, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, pp. 83-84, Pl. VIII, fig. 11. (Described
and discussed as below as a new species. Fig. 11 is copied in this monograph, Pl. LVIII, fig. 6c.)

All the specimens representing this species are flattened by compression in the argillaceous
shale, also more or less distorted. The outline of figure 6 (Pl. LVIII) is probably the nearest
the original outline of the ventral valve, and figure 6c of the dorsal. A ventral valve 6 mm.
in length has the apex 1.5 mm. from the posterior margin. A cast of the interior of a ventral
valve (Pl. LVIII, fig. 6b) indicates a relatively large interior opening for the pedicle tube;
a short, small visceral cavity with the shell thickened so as to form a short ridge; and an obscure
false area; also that the posterior margin is arched slightly above the plane of the margin of
the valve. An exterior cast shows the impression of a minute elongate tubercle on each side
of the apex, and a small pedicle opening just back of them. A cast of the interior of a dorsal
valve shows a short median ridge, and the posterior portion of the main vascular sinuses.

The exterior cast shows that the surface was marked by small concentric ridges and lines
of growth, a few low, obscure, rounded, radiating ridges, and fine granulations or tubercles
on very minute, irregular, more or less inosculating concentric ridges, or the same type of
surface as that of Acrothele coriacea Linnarsson. If these shells were found at the same horizon
in Sweden as A. coriacea I think they would be referred to that species except that the apex
of the ventral valve of the French species is much nearer the ia see margin; more perfect
specimens would probably show other differences.

This species appears to differ from <Acrothele Pie ee TBennaysel and A. bohemica
(Barrande) by the more anterior position of the apex of the ventral valve.

In response to a request for permission to study the Cambrian brachiopods that he had
collected from Montagne Noire, Mr. Miquel very courteously sent me a number, and among
them I found this species, and, with his permission, have described it.

It gives me pleasure to give the specific name in recognition of the discovery by Prof. J.
Bergeron of the Middle Cambrian fauna of Hérault, and his fine work on the fauna.

FoRMATION AND LOCALITY.—Middle Cambrian: (342 [Miquel, 1893, p. 9]) Shales in Montagne Noire, Coulouma,
Department of Hérault, France.

ACROTRETID. 639

ACROTHELE BOHEMICA (Barrande).
Plate LVII, figures 1, la-d.

Obolus? bohemicus BARRANDE, 1879, Systéme silurien du centre de la Bohéme, vol. 5, pt. 1, Pl. CII, figs. vm: 1-3.
(Not described, but figured as a new species. Figs. vm: 1-2 are reproduced in this monograph, Pl. LVI, figs.
1 and la, respectively.)

Acrothele bohemica (Barrande), Watcort, 1886, Bull. U. 8. Geol. Survey No. 30, p. 107. (Merely changes generic
reference.

Acrothele eee (Barrande), Hau and CraRrKE, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, p. 101.
(Suggests reference to Acrothele.)

Acrothele bohemica (Barrande), Pomprcxs, 1896, Jahrb. K.-k. geol. Reichsanstalt for 1895, Bd. 45, Hft. 3, pp. 509-511,
Pl. XIV, figs. 7-15. (Described and discussed in German. Figs. 8b, 11b, and 10b are reproduced in this
monograph, Pl. LVII, figs. 1b, 1c, and 1d, respectively.)

Barrande did not publish a description of this species, but Pompeckj [1896b, p. 509] gives
an extended description based on a large number of specimens. From this and the accom-
panying illustrations it appears that the general form is much like that of Acrothele coriacea
Linnarsson. It differs from the latter in having the apex nearer the posterior margin and
in having a concentrically striated surface and undulating lines instead of granulose surface;
these characters also distinguish A. bohemica from A. (Redlichella) granulata (Linnarsson).
The student should carefully examine the series of figures accompanying Pompeckj’s descrip-
tion as well as those of Barrande. Copies of the latter are inserted on Plate LVII, figures 1
and 1a, and copies of Pompeckj’s figures on Plate LiVII, figures 1b, 1c, and 1d.

The posterior position of the apex of the ventral valve suggests in this respect Acrothele
prima (Matthew) (Pl. LXI, fig. 6) and Acrothele prima costata’ (Matthew) (Pl. LXI, figs. 4
and 4a), but in surface characters and outline of the valves the species differ, as indeed they do
in the apex of A. prima being nearer the margin than that of A. bohemica. Comparison should
be made with A. quadrilineata Pompeckj, which is closely allied to this species.

The specific name is derived from Bohemia.

FORMATION AND LOCALITY.—Middle Cambrian: (345 [Pompeckj, 1896b, p.509]) Greenish shale in the Paradoxides
zone, on the Dlowh4 Hora, above the brook of Sbirov, near Skrej; (345a [Pompeckj, 1896b, p. 511]) shales in the Para-
doxides zone, on the right bank of the brook of Kardsek, near Tejfovik; (345b [Pompeckj, 1896b, p. 511]) in the
“Bande de Jinec,”’ at Felbabka and Jinec; and (845¢) in Etage CO [Barrande, 1879b, Pl. CII], at Mleschitz; all in Bohe-
mia, Austria-Hungary.

Nenowsmide BORGHOLMENSIS Walcott.
Plate LXIII, figures 2, 2a-b.

Acrothele borgholmensis Watcort, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, pp. 84-85, Pl. VIII, fig. 12. (De-
scribed and discussed as below as a new species. Figs. 12 and 12’ are copied in this monograph, Pl. LXIII,
figs. 2 and 2a, respectively.)

General form subcircular to broad oval. Ventral valve subconical, with the apex a short
distance back of the center. A clearly defined false area extends from the apex to the margin;
it is defined by a slight depression and a low ridge at the outer edges; two or three longitudinal
lines extend to the margin, and the concentric lines of growth of the shell cross it without inter-
ruption. An elongate, small foraminal aperture occurs just back of and beneath the apex.

The outer surface of the shell is of a dull, dark color, and marked by slightly undulating,
clearly defined, concentric striz; the inner layers are marked by fine radiating and concentric
lines. The shell is built up of thin lamellz arranged in concentric layers that are slightly
oblique to the surface layer. Shell substance corneous. Nothing is known of the interior
of the valves except the sharp median ridge of the dorsal valve.

The largest specimen has a diameter of 4 mm.; the average size is about 3 mm.

Observations.—The convexity, position of the apex, and clearness of the false area depend
upon the degree of compression and distortion the shells have received. I have described
what appears to be the uninjured shell.

640 CAMBRIAN BRACHIOPODA.

The subcentral position of the apex seems to distinguish this species. It is associated
with Obolus (Bréggeria) salteri (Holl) and Lingulella lepis (Salter).
The specific name is derived from Borgholm, the type locality.

ForMATION AND LOCALITY.—Upper Cambrian: (310d) Ceratopyge slate at Borgholm, Oeland Island, Sweden.

ACROTHELE CERATOPYGARUM (Brégger).
Plate LXIII, figures 1, la-c.

Discina (Acrotreta?) ceratopygarum BROaGER, 1882, Die silurischen Htagen 2 und 3, p. 47, Pl. X, figs. 1, la-b. (De-
scribed in German. Figs. la and 1b are reproduced in this monograph, Pl. LXIII, figs. 1 and la, respectively.)

Acrothele ceratopygonum Waxcott, 1902, Proc. U. 8. Nat. Mus., vol. 25, p. 598. (Mentioned in discussion of Acrotreta
seebacht.

Acrothele ees (Brégger), Mopere and SrcerBere, 1906, Medd. fran Lunds Geol. Faltklubb, Ser. B, No. 2

(Aftryck ur K. Fysiografiska Sallskapets Handl., N. F., Bd. 17), p. 67. (Mentioned in Swedish.) .
Acrothele barbata Moprre and SEGERBERG, 1906, idem, pp. 67-68, Pl. III, figs. 7-10. (Described and discussed in

Swedish as a new species.)

Ventral valve conical, with eccentric apex. False area well defined and marked midway
by a narrow, slightly elevated ridge that does not extend quite to the margin of the shell; on
the interior of the shell a narrow furrow extends nearly to the margin where it is cut off by
a transverse ridge just within the margin. Foraminal aperture minute, situated at the top
of the false area just below the apex; in the exfoliated shell it appears to be elongate. The
outer surface of the shell appears in a cast to be nearly smooth; the inner layers or lamelle
are marked by fine concentric and radiating lines. A cast of the interior shows a very small
visceral area just in front of the apex, and a cardinal muscle scar on each side of the median
line back of the cast of the foraminal opening. The two ventral valves measure 5 mm. in
diameter; height, about 2 mm.

From Moberg and Segerberg’s description [1906, p. 67] of the dorsal valve of Acrothele
barbata the following is taken: ‘‘The dorsal valve is nearly flat, or with the posterior and cen-
tral parts slightly arched; beak marginal.’ The interior shows a few traces of muscle scars.
The interior of the ventral valve shows the main vascular sinuses and branches very much as
in Acrothele coriacea Linnarsson (Pl. LVI, figs. 1a, 1d). These authors give the dimensions
of one of the larger shells as, length, 5.25 mm.; width, 6 mm.; elevation, 1.5 mm.

Observations.—Through the courtesy of Doctor Brégger I have had the opportunity of
studying the type specimens of this species. One of them is illustrated (Pl. LXIII, fig. 1c),
and I have also copied two of Brégger’s figures. The species is related to Acrothele borghol
mensis Walcott from the Ceratopyge slate, but differs in the character of the false area and
median ridge of the latter. It is also a larger and more convex form.

Specimens from Vestfossen, Norway, one of which is illustrated on Plate LXIII, figure 1b,
have the same form as the shells described by Moberg and Segerberg under the name of Acro-
thele barbata [1906, p. 67], and I find bits of the outer shell showing the ‘‘coarse, irregular,
anastomosing, concentric ridges”’ characteristic of Acrothele barbata; a little trace of the marginal
fringe is also shown on one specimen. The fact that the two species occur at the same strati-
graphic horizon in Sweden and Norway, and the fact that they have the same specific characters,
lead me to place A. barbata as a synonym of Brégger’s A. ceratopygarum.

This species derives its specific name from its occurrence in the Ceratopyge limestone.

ForRMATION AND LOCALITY.—Passage beds between the Upper Cambrian and the Ordovician: (828h [Brégger,

1882, p. 17]) blue Ceratopyge limestone, at Vestfossen, 10 miles (16.1 km.) west-southwest of Christiania, Norway.
(310 [Moberg and Segerberg, 1906, p. 67]) Ceratopyge limestone (zone 4), at Ottenby, on Oeland Island, Sweden.

L ACROTHELE COLLENI N. sp.
Text figures 55A-E, page 641; Plate LXIII, figures 6, 6a—b.

This species is represented by numerous specimens of both valves, but only the exterior
of the valves is known. ‘The ventral valve is subconical, with the apex a little in front of the

ACROTRETIDE. 641

posterior third; the slope from the apex to the posterior margin is about 45° and that to the
anterior margin 20°. The posterior slope is marked by a rather clearly defined false area,
which is slightly flattened, and marked midway by a very slight depression; the apical opening
is small, oval in outline, and situated on the posterior side of the apex. On finely preserved
specimens the front and sides of the apical opening have a narrow, slightly elevated ridge,
and a trace of a small tubercle on each side at the anterior end of the opening; the posterior
margin arches very slightly beneath the false area. The dorsal valve is moderately convex,
and most prominent on the umbo, with the apex at the posterior margin.

One of the largest ventral valves has a length of 9 mm.; width, 10 mm. The dorsal valve
has a length of 7 mm.; width, 8 mm. These proportions vary somewhat as the shells are
more or less distorted by compression in the shale. Shell substance corneous.

The exterior surface is marked by very fine, concentric ridges of growth, with depressed
and elevated lines between them; there are also numerous low, rounded, narrow, radiating
ridges that vary in strength and number on different specimens; on some shells there is hardly
a trace of the radiating ridges, and on others they are numerous, especially on the sides; one
dorsal valve shows nine on each side, with a few scattered through the central portion in addi-
tion to the concentric and radiat-
ing lines; there is also a system of
exceedingly minute and irregular,
more or less inosculating, but, as
a whole, concentric ridges, upon.
which very minute tubercles oc-
eur. These are most perfect over
the posterior half of the shell, but
extend in many examples to the
front margin.

A cast of the apical portion
of the dorsal valve shows that the
pedicle aperture enlarged as it
passed through the shell, and

that the visceral area was short. FicuRE 55.—Acrothele colleni n.sp. A, Slab showing a ventral and a dorsal valve (U. S.
. : : . Nat. Mus. Cat. No. 51410a). B, Broken ventral valve showing false area (U.S. Nat.
Observations.—This specs 1s Mus. Cat. No. 51410b) (X about 4). C, A much larger ventral valve than that represented
of the Acrothele corvacea Linnars- by B (U.S. Nat. Mus. Cat. No. 51410c). D, Cast of a ventral valve showing the incurv-
ing of the flexure lines across the false area (U.S. Nat. Mus. Cat. No. 51410d) (Xx about 4).

son. type. It has the See sur E, Dorsal valve (U. S. Nat. Mus. Cat. No. 51410e).
face, except that the irregular, The specimens represented are from Locality 35c, a drift block of Lower Cambrian

concentric ridges and tubercles shales, on the slopes of Mount Bosworth, on the Continental Divide, 1 mile (1.6 kam.) east
‘) of Hector, British Columbia.

are finer.

The Lower Cambrian specimens from British Columbia appear to be identical with those
from Montana and they are associated with the same subfauna, of which Albertella helena
Walcott is considered to be typical. The shells from the Middle Cambrian, which occur 2,450
feet higher in the section on Mount Stephen, have the same form and surface markings and
appear to be identical in all respects. It is interesting to note that Micromitra (Iphidella)
pannula (White) has a similar vertical range.

The specific name is given for Mr. M. Collen, of White Sulphur Springs, Montana, who
collected the finest specimens at the locality on Scapegoat Mountain, Montana.

FoRMATION AND LOCALITY.—Middle Cambrian: (14s) About 2,300 feet (701 m.) above the Lower Cambrian and
2,700 feet (823 m.) below the Upper Cambrian, in the Ogygopsis zone of the Stephen formation [Walcott, 1908f, p. 210],
on the northwest slope of Mount Stephen, above Field on the Canadian Pacific Railway, British Columbia, Canada.

(4q) About 315 feet (96 m.) above the unconformable base of the Cambrian and 190 feet (57.9 m.) above the top of the
quartzitic sandstones, in a shale which corresponds in position to the wpper part of shale No. 6 (Lower Cambrian) of the

Dearborn River section [ Walcott, 1908f, p. 202] on the ridge between Gordon and Youngs creeks, about halfway between
Gordon Mountain and Cardinal Peak, Ovando quadrangle (U.S. Geol. Survey), Powell County, Montana.

62667°—vo1 51, pr 1—12——41

642 CAMBRIAN BRACHIOPODA.

Lower Cambrian: (57e) About 115 feet (35 m.) below the Middle Cambrian, in limestone correlated with the top
of le of the Mount Whyte formation on Mount Bosworth [Walcott, 1908f, p. 213], just above the tunnel on the north
shoulder of Mount Stephen, about 3 miles (4.8 km.) east of Field, British Columbia; (35¢) drift blocks supposed to
have come from the Mount Whyte formation [Walcott, 1908f, p. 214], found on the south slope of Mount Bosworth, a
short distance northwest of the Canadian Pacific Railway track between Stephen and Hector, eastern British Columbia;
and (35e) about 270 feet (82.3 m.) below the Middle Cambrian, in a greenish siliceous shale correlated with No. 3 of
the Mount Whyte formation on Mount Bosworth [Walcott, 1908f, p. 214], in the amphitheater between Popes Peak and
Mount Whyte, about 3 miles (4.8 km.) northwest of Lake Louise, southwest of Laggan on the Canadian Pacific Railway,
Alberta, Canada.

(4v) About 200 feet (61 m.) above the unconformable base of the Cambrian and 75 feet (22.9 m.) above the top of
the quartzitic sandstones, in a shale which corresponds in stratigraphic position to shale No. 6 of the Dearborn River
section [Walcott, 1908f, p. 202], on Gordon Creek, 6 miles (9.6 km.) from South Fork of Flathead River, Ovando quad-
rangle (U. S. Geol. Survey), Powell County, Montana.

ACROTHELE CORIACEA Linnarsson.

Plate LVI, figures 1, la-i-

Acrothele coriacea LINNARSSON, 1876, Bihang till K. svensk Vet.-Akad. Handl., Bd. 3, No. 12, pp. 21-23, Pl. IV, figs,
44-48. (Described and discussed in Hnglish as a new species.) .

Acrothele coriace Linnarsson, BroGGER, 1878, Nyt Magazin for Naturvidenskaberne, Bd. 24, Hit. 1, p. 76, Pl. IV,
fig. 11. (Mentioned.) f

Acrothele coriacea Linnarsson, GRONWALL, 1902, Danmarks geol. Undersggelse, Reekke 2, No. 13, p. 40. (Localities
mentioned in Norwegian.)

General form subcircular to transversely broad oval in outline, with the posterior margin
slightly transverse. Ventral valve slightly conical with the apex usually within the posterior
fourth of the distance from the front to-the back margin. The apex, as usually seen, is formed
of two minute, elongated tubercles with a narrow, elongate depression between them; at the
posterior end of this depression a minute pedicle aperture occurs; on some shells the two
minute tubercles unite in front so as to form a ring with a break at the back side just behind
which the pedicle aperture opens. The size of the tubercles and median depression varies in
different shells, and also with the amount of exfoliation of the outer shell. In some examples
when the shell is nearly all exfoliated at the apex and umbo the two tubercles are prominent
and a third tubercle occurs back of them which is the cast of the inner portion of the foraminal
tube. A narrow false area is faintly defined on some shells and more distinctly on others. A
median line often extends from the foraminal aperture to the margin. Casts of the interior show
a much more distinctly defined false area, also that it 1s impressed in the shell. The strie of
growth cross the area without interruption except as they curve slightly upward at the center
on some shells. Linnarsson [1876, p. 21] states that there is no trace of a longitudinal groove
as in Acrotreta subconica Kutorga; this is true of most specimens, but on others from the Para-
doxides forchhammeri zone, | find a narrow line and on others a curving upward of the concentric
striz at the median line. The dorsal valve is slightly convex near the umbo, from which it
curves rather abruptly down to the posterior margin and in some shells the lateral and anterior
margins curve up a little, leaving a slightly concave surface between the margins and the umbo.
The apex is near the posterior margin; it is divided midway by a narrow furrow so as to form
a narrow elongate tubercle on each side. On some shells a slight depression or flattening
extends to about the middle of the valve.

The exterior surface is marked by concentric lines and strie of growth and slight undula-
tions or ridges on the older shells; a few rather faintly indicated, radiating costz occur on some
examples of the ventral valve. Linnarsson [1876, p. 21] describes the outer surface as being
rough, somewhat like leather. With a strong magnifier I find this to be caused by a minute
granulation on fine, irregular, slightly elevated striz. The shiny inner layers of the shell
are marked by concentric lines and very fine radiating lines.

The shell is corneous and built up of numerous thin layers or lamelle so as to form a
shell that is strong at the umbo and thin toward the margins. The largest ventral valve in

ACROTRETIDZ. 643

the material available has a length of 8 mm. and a width of 10 mm. The average size is
from 5 to 6 mm. in length, with a greater width.

The interior of the ventral valve shows a rounded, slightly depressed visceral area, which
forms a semicircular area about the well-defined apical callosity and pedicle opening; back of
the latter the false area is usually clearly defined. From each side and a little back of the
pedicle opening in the ventral valve a rather strong main vascular sinus arches outward and
then forward to the anterior half of the valve, where it divides into two or more branches;
numerous lateral sinuses branch off and extend nearly to the margin, and a few shorter branches.
extend toward the central section. In the dorsal valve the vascular markings include the
main vascular sinuses, which extend obliquely forward and outward, and an elaborate series.
of canals that originate in advance of the visceral area (Pl. LVI, figs. 1d and 1f).

Our salomane sion as to the muscle scars of the ventral valve is limited to a suggestion of
small cardinal scars on each side of the false area a little back of the main soseullan sinuses.
Tn the dorsal valve small cardinal scars (cl) occur on each side of the median ridge back of
the base of the main vascular sinuses; small centrals (h) also occur on each side near the
anterior end of the median ridge.

Observations—The above ‘description i is made from the study of a large number of speci-
mens from several localities in Sweden, and a fine locality on Boenbolr Island, Denmark.
It differs somewhat from Linnarsson’s [1876, p. 21], chiefly as the result of my pana more
and somewhat better preserved material for study. He describes an umbonal muscle scar
in the dorsal valve, but from his illustration [1876, Pl. IV, fig. 48b] I am inclined to think that
the scar is only a bit of the false area, the inner shell having been exfoliated.

The relations of the species are with Acrothele (Redlichella) granulata (Linnarsson), from
which it differs in smaller average size, more finely granulated surface, and, what is of more
value, in the form of the muscle scars of the dorsal valve.

This type of Acrothele is widely distributed. It is represented in Bohemia by A. bohemica
(Barrande) and A. quadrilineata Pompeckj; in France by A. bergeront Walcott; in North Amer-
ica by A. matiheur (Hartt) and its varieties; and in China by A. matthewi eryx “Walcott.

ForMATION AND LOCALITY.—Passage beds between the Upper Cambrian and the Ordovician: (8x) Limestone
at Slemmestad, about 3 miles (4.8 km.) southwest of Christiania, Norway.

Upper-Middie Cambrian: (310i) Passage beds between the Middle Cambrian Paradowides forchhammeri zone
and the Upper Cambrian Olenus truncatus zone at Borgholm, Oeland Island, Sweden.

Middle Cambrian: @ (16h and 334h) Limestones of Paradowides forchhammeri zone at Borregaard; (16 1) limestones
of Paradoxides davidis zone at Borregaard ; (334b) 6 Andrarum limestone at Borregaard; (384c) > in the Baagaraoesieos tessim
zone at Borregaard; (334d) 6 in the zone with Agnostus parvifrons at Borregaard; (3348) limestone on Bornholm Island;
(16j) limestone of Paradoxides forchhammeri zone at Laesaa; (16k) limestones of Paradoxides davidis zone at Laesaa;
(334e) Andrarum limestone at Laesaa; all on Bornholm Island, Denmark.

(8w) Limestones of the Paradoxides forchhammert zone, at Andrarum, 20 miles (32 km.) northwest of Simris-
hamn, Province of Christianstad; (3200) ¢ limestone band between the Holmia kjerulfi zone and the Paradoxides tessini
zone at Andrarum, 20 miles (32 km.) northwest of Simrishamn, Province of Christianstad; (320f) limestone at Andrarum,
20 miles (32 km.) northwest of Simrishamn, Province of Christianstad; (3201) drift blocks from the Paradomides wlandicus
zone at Lillviken, near Oestersund, Jemtland; (320m) ¢ limestones of the Paradoxides forchhammeri zone at Kinnekulle,
northeast of Lidképing, Province of Skaraborg; (320n) limestones of the Paradoxides forchhammeri zone at Lovened,
Djupadal, 19 miles (30.6 km.) south-southeast of Skara, Province of Skaraborg; (821q) limestones of the Paradoxides
JSorchhammert zone at Munkesten, north of Hunneberg, Province of Skaraborg; (320r) limestones of the Agnostus lxvi-
gatus zone, at Hunneberg, western boundary of the Province of Skaraborg; (820y) limestones of the Paradozxides forch-
hammeri zone at Gudhem, 12.5 miles (20.1 km.) south-southeast of Skara, Province of Skaraborg; (320b) limestone
forming 2d of the Paradoxides zone, the Agnostus levigatus horizon, at Gudhem, 12.5 miles (20.1 km.) south-southeast
of Skara, Province of Skaraborg; (320v)¢ in the Paradozxides forchhammeri zone at Lanna, Hjulsta, Vinala, and Vrana,
all four in Nerike; (320p) ¢ limestones of the Paradoxides forchhammeri zone at Sédra Méckleby, southern part of Oeland
Island; (320g) limestones of the Paradoxides forchhammeri zone at Borgholm, Oeland Island; and (320q) limestone form-
ing 2c of the Paradoxides forchhammeri zone, at Alunbruk (alum works), southern part of Oeland Island; all in Sweden.

(324b) Shales of Etage 1c [Brégger] at Krekling, in Sandsvar; (324c) shales of Etage 1d at Krekling, in Sandsvar;
and (324a) shale of Htage 1c [Brégger] at Skrena, Skiensdalen; all [Christiania Univ. Min. Inst. Coll.] in Norway.

a This species also occurs in Locality 320k. b Gronwall, 1902, p. 40. ce Linnarsson, 1876, p. 23.

644 CAMBRIAN BRACHIOPODA.

ACROTHELE DECIPIENS Walcott.

Y

Plate LVIII, figures 3, 3a-d.

Acrothele decipiens Watcort, 1897, Proc. U. S. Nat. Mus., vol. 19, p. 716, Pl. LX, fig. 2. (Described and discussed
as a new species. The specimen represented by fig. 2 is redrawn in this monograph, Pl. LVIII, fig. 3a.)
General form of the ventral valve subcircular, usually a little longer than wide; moderately

convex; apex at the posterior one-sixth to one-eighth of the valve. Pedicle aperture of medium
size, situated on the posterior slope of the summit of the apex; the slope from the apex to
the posterior margin is rather abrupt; and very gentle to the front margin. The obscure
false area, with a faintly defined groove down its center, is shown on some specimens. Dorsal
valve oval, moderately convex, and marked by a shallow depression extending from the back
to the front; apex marginal.

Surface marked by fine, concentric lines of growth, and very fine, somewhat irregular,
and sometimes inosculating ridges upon which occur exceedingly minute tubercles which give
a very finely tuberculated surface; some specimens show depressed, narrow, rounded ridges
extending from near the apex to the margins; these ridges vary in size and number. Shell
substance corneous.

Nothing is known of the interior of the ventral valve except a cast of the apical callosity
(Pl. LVIII, fig. 3a). The interior of the dorsal valve has a strong median ridge that extends
forward beyond the center, and strong cardinal scars.

Observations.—This species is of the Acrothele matthewi (Hartt) type. It has a similar
surface, and the apex of the ventral valve is well toward the posterior margin. The interior
of the dorsal valve suggests that of Acrotreta more than do most interiors of the dorsal valves
of Acrothele. It has an unusually long and strong median ridge and cardinal muscle scars.

Acrothele decipiens was found associated with fragments of Olenellus in the fine gray lime-
stone in the Lower Cambrian shale.

FoRMATION AND LOCALITY.—Lower Cambrian: (50) Shaly limestones, 1.125 miles (1.8 km.) north of Stoner, 10
miles (16.1 km.) east-northeast of York; and (846) limestone and shale a little south of Emigsville; both in York County,
Pennsylvania.
ACROTHELE DicHoToMA Walcott.

Plate LX, figure 2.

Acrothele? dichotoma Waucortt, 1884, Mon. U. S. Geol. Survey, vol. 8, pp. 14-15, Pl. IX, fig. 11. (Described and

discussed as a new species. The specimen represented by fig. 11 is redrawn in this monograph, Pl. LX, fig. 2.)
Acrotreta dichotoma Waxcort, 1886, Bull. U. S. Geol. Survey No. 30, p. 107. (Suggests reference to Acrotreta.)
Acrotreta dichotoma (Walcott), Hatt and CrarKe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, pp. 100 and

103. (Mentioned.)

Shell of medium size, thin, corneous, nearly circular in outline, the transverse diameter
being a little greater than the longitudinal. Ventral valve depressed, discoid, with the apex
but slightly elevated above the general plane of the surface and situated about one-third the
distance from the posterior to the anterior margin. The apex is exfoliated, but the inner layers
show that it was perforate and that in the interior the shell was thickened about the pedicle
opening. The slightly depressed area is triangular in form, and extends to the posterior
margin, gradually expanding to a width of a little less than its length; it appears to have
been quite minute at first, just beneath the apex, and to have been filled in by successive addi-
tions of the shell, so that the generally circular outline of the shell has scarcely been broken
by the very slight truncation of the posterior margin. The additions to the posterior margin
of the false area are crowded together as little transverse ridges with fine strie between.

The outer portion of the shell is largely exfoliated, but traces of radiating striz and con-
centric lines of growth are shown. The latter on the outer portion appear to have been con-
tinuous with those crossing the pseudodeltidium. From each side of the apex a narrow, main
vascular sinus gently diverges, extending toward the central portion of the shell. Transverse
diameter, 7.5 mm.; longitudinal diameter, 6.75 mm.; elevation or convexity, about 0.75 mm.

ACROTRETIDA. 645

When describing this species in 1884 I was not aware that a false area was present on
some ventral valves of the type species of the genus, and that the supposed muscle scars were
the main vascular sinuses. This caused me to question the generic reference.

The ventral valve of Acrothele dichotoma has the same general form as A. subsidua (White),
but it has a thicker shell, and, so far as known, a concentrically striated surface.

ForMATION AND LOCALITY.—Middle Cambrian: (58) Shaly limestone in upper beds of the Secret Canyon shale,
east side of New York and Secret canyons, Eureka district [Hague, 1892, Atlas], Hureka County, Nevada.

ACROTHELE GAMAGEI (Hobbs).

Plate LX, figures 5, 5a—c.

Obolella gamagei Hosss, 1899, Am. Geologist, vol. 23, No. 2, pp. 114-115, figured. (Described, figured, and discussed
as a new species.)

Acrothele gamagei (Hobbs), GraBaAv, 1900, Occas. Papers Boston Soc. Nat. Hist., No. 4, vol. 1, pt. 3, pp. 615-617; fig.
48, p. 617; Pl. XX XI, figs. la-d. (Described and discussed. Fig. 48is copied from the figure accompanying
the preceding reference.)

Acrothele gamagei (Hobbs), Saimer, 1907, Am. Jour. Sci., 4th ser., vol. 24, pp. 176 and 177. (New locality mentioned.)

Acrothele gamagei (Hobbs), GRaBAU and Saimer, 1907, North American Index Fossils, vol. 1, p. 200. (Character-
ized.)

General form subcircular to transversely broad oval in outline, with the posterior margin
slightly transverse. Ventral valve slightly conical with the apex at about the posterior fifth
of the length of the valve; the apex is formed of two elongate tubercles with a slight depression
between them; at the posterior end of the depression a small pedicle opening occurs; back of
the pedicle opening a more or less indistinctly defined false area extends to the posterior margin;
the posterior margin of the valve arches slightly upward.

The dorsal valve is gently convex with posterior portion curving slightly downward so as
to fit closely into the upward-curving margin of the ventral valve; beak marginal.

The surface is marked by narrow, concentric undulations of growth, a few obscurely defined,
radiating ribs and fine, concentric, irregular, undulating, elevated lines; the latter have numerous
minute tubercles on them over the central portions of the shell, and sometimes on the outer
lines of the old shells; this results im a finely granulated surface that may be seen with the aid
of a strong lens. The concentric lines cross the false area with only slight irregularity. The
shell appears to be corneous and built up of several thin layers or lamelle.

The interior of the ventral valve shows an elongate depression on each side of the apex, a
small visceral area, and not very strongly defined main vascular sinuses that originate back of
the pedicle opening and curve forward into the body of the valve. The interior of the dorsal
valve has a low, rounded, median ridge that extends forward of the center where it bifurcates;
a narrow, sharp, median septum occurs on the posterior portion of the ridge; the main vascular
sinuses originate near the posterior margin beneath the beak and extend obliquely forward
into the valve.

The only muscle scars seen are the elongate, oval central scars of the dorsal valve, which
are situated on the slopes of the median ridge back of the transverse center of the valve.

Observations.—As stated by Grabau [1900, p. 615] this is the Massachusetts representative
of Acrothele matthewi (Hartt) of the St. John formation of New Brunswick. With the additional
information, afforded by a collection made by William P. Rust for the United States National
Museum, the similarity between the two forms is still more striking; they have the same general
form, surface, and convexity; but A. gamagei attains a larger size and differs in the position of
its main vascular sinuses; the latter may be seen by comparing Plate LX, figures 5b and 5c,
with Plate XLI, figures 1c and 1d.

The specific name was given in honor of Miss A. O. Gamage, of South Bristol, Maine.

FoRMATION AND LOCALITY.—Middle Cambrian: (326b [Grabau, 1900, p. 617]) Braintree slate, below high tide about

100 feet (30.5 m.) east of the quarry at East Braintree, Abington quadrangle ( U.S. Geol. Survey); and (5) siliceous shale on
Hayward Creek, Braintree, Dedham quadrangle (U. 8. Geol. Survey); both in Norfolk County, Massachusetts.

646 CAMBRIAN BRACHIOPODA.

ACROTHELE INTERMEDIA Linnarsson.
Plate LVI, figures 3, 3a-d.

Acrothele intermedia LINNARSSON, 1879, Sveriges Geol. Unders6kning, Afhandl. och Uppsatser, Ser. C, No. 35, pp.
25-27, Pl. III, figs. 40-44. (Described in Latin, and described and discussed in Swedish, as a new species.
Figs. 40-44 are reproduced in this monograph, Pl. LVI, figs. 3, 3a-d, respectively.)
Acrothele intermedia Linnarsson, GRONWALL, 1902, Danmarks geol. Undersggelse, Reekke 2, No. 13, p. 39. (Localities
~ mentioned in Norwegian. )
A comparison of the figures of Acrothele intermedia on Plate LVI, with those representing
A. coriacea Linnarsson and A. (Redlichella) granulata (Linnarsson) on the same plate, shows
very clearly that A. intermedia is related in form to both, but that it differs in narrowing pro-
portionately more toward the posterior margin. Linnarsson [1879, p. 26] states that in surface
characters it agrees more nearly with A. coriacea. The outer surface is described as having
numerous fine concentric strie without granules. He gives [1879, p. 26] the dimensions of two
ventral valves as “‘length 8 and 6 mm., width 9.5 and 7 mm., respectively.” A dorsal valve
9 mm. in length has a width of 11 mm. ; 5
I have not seen the type of this species, or found specimens of it in the collections received
from Sweden. Five of Linnarsson’s figures are reproduced on Plate LVI. Two of these show
a somewhat different position and arrangement of the main vascular canals and branches of
the ventral valve than in A. coriacea Linnarsson.

FoRMATION AND LOCALITY.—Middle Cambrian: (16h) Limestones of the Paradowides forchhammeri zone at Borre-
gaard; and (334a [Grénwall, 1902, p. 39]) limestones of the Conocoryphe exsulans zone at Borregaard; both on Born-
holm Island, Denmark.

(320h) Shales in the Paradoxides tessini zone at Lovened, Province of Skarabore; (320i) limestones of the Coronatus
zone, at Andrarum, 20 miles (32 km.) northwest of Simrishamn, Province of Christianstad; (820j) limestones of the Coro-
natus zone, at Gisléf, Province of Malméhus; and (320k) limestones of the Coronatus zone, at Kiviks Hsperéd, Province of
Malméhus; all [Gronwall, 1902, p. 39] in Sweden.

(320q) Limestone forming 2c of the Paradoxides forchhammeri zone at Alunbruk (alum works), southern part of
Oeland Island, Sweden.

Specimens that are rather doubtfully compared with Acrothele intermedia occur at the fol-
lowing locality:

Upper Cambrian: (304j [Mason College Coll.]) Lower Stockingford shales, Puxley Park Lane, halfway up the
path to the quarry, Atherstone, Warwickshire, England.

ACROTHELE LEVISENSIS Walcott.
hee Plate LXXXI, figures 12, 12a-b.
Acrothele levisensis Waucortt, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, p. 85, Pl. VIII, fig. 13. (Described and
discussed as below as a new species. Fig. 13 is copied in this monograph, Pl. LX XXI, fig. 12.) }

Outline transversely broad ovate, ventral valve moderately convex at the apex, which
is about the posterior fifth of the length of the valve; pedicle aperture small and situated on
the slope back of and near the apex. Dorsal valve depressed convex, with a very gentle slope
from the umbo to the front margin and a greater slope to the marginal beak.

Surface marked by fine concentric lines and striz that cross the space back of the apex
without apparent interruption. A compressed ventral valve 8 mm. in length has a width
of 10 mm. A dorsal valve has a length of 7 mm.; width, 8 mm.

The cast of the interior of a compressed dorsal valve shows a median ridge that expands
near the center of the valve, and a main vascular sinus on each side that has the same general
course as in Acrothele coriacea Linnarsson.

Observations.—In general form this species is much like Acrothele coriacea and related
species. It differs from them in having a smooth surface except for the concentric lines and
strie.

The four specimens representing this species were attached to a block in the collections
of the Geological Survey of Canada, with specimens of Hlkania desiderata (Billings).

The specific name is derived from Point Levis, the type locality.

FoRMATION AND LOCALITY.—Lower Ordovician: (319a [Geol. Survey Canada]) Levis shale, Point Levis, Province
of Quebec, Canada.

ee

ACROTRETIDA. 647

vy ACROTHELE MACULATA (Salter).

Plate LVIL, figures 2, 2a-b; Plate LVIII, figure 2.

Obolella maculata (Hicks MS.) Saurer, 1866, Rept. British Assoc. Adv. Sci. for 1865, p. 285. (Name merely listed.)

Obolella maculata Salter, Davipson, 1868, Geol. Mag., vol. 5, p. 311, Pl. XVI, figs. 1-8. (Described as below, and
discussed. Figs. 1-3 are reproduced in this monograph, Pl. LVII, figs. 2, 2a-b, respectively.)

Obolella maculata Salter, Daviwson, 1871, British Fossil Brachiopoda, vol. 3, pt. 7, No. 4, p. 341, Pl. L, figs. 18-21.
(Copy of preceding reference. Figs. 18, 19, and 21 are copied from Davidson, 1868, Pl. XVI, figs. 1, 2, and 3,
respectively.)

Not Obolella maculata DELGADO, 1904, Communicagdes Commissao Servico Geol. Portugal, tome V, fase. 2, p. 364,
Pl. IV, fig. 24. (Described in French. This species is referred in this monograph to Acrothele villaboimensis.)

The description by Davidson [1868, p. 311] follows:

Shell small, transversely oval, valves moderately convex; 4 lines in length, by 5in breadth. Beak very obtusely
acuminated; front broadly rounded; greatest breadth at about the middle of the shell; surface smooth, marked only
by fine concentric lines of growth. Interior incompletely known.

From the above description it is not possible to refer this species to Acrothele, but the
figure given of the interior of the dorsal valve clearly indicates that genus. All of the figures
given by Davidson appear to be of dorsal valves. It would be interesting to know if the
specimens illustrated by Davidson [1871, Pl. LIX, figs. 41a, 42a] as ‘‘Discina pileolus Hicks”’
are associated with the specimens illustrated as “Obolella maculata Hicks” [Davidson, 1871,
Pl. L, figs. 18-21].

With our present information it is difficult to make comparisons with other species of
Acrothele further than to call attention to the similarity of the interior of the dorsal valve to
that of Acrothele subsidua (White) (Pl. LX, fig. 1k).

FORMATION AND LOCALITY.2—Middle Cambrian: (318d [Davidson, 1871, p. 341]) Sandstone in the middle portion
of the Menevian at Porth-y-rhaw, St. Davids; and (318h) shales in the Menevian at St. Davids; both in South Wales.

(318e) Lower portion of the Menevian, at Camlan; and (318f) lower portion of the Menevian at Gwynfynydd;
both [Davidson, 1871, p. 341] in North Wales.

ACROTHELE MATTHEW! (Hartt).

Plate LX1I, figures 1, la-g.

Lnngula matthewi Hartt, 1868, Acadian Geology, by Dawson, 2d ed., p. 644, fig. 221. (Described as a new species.
The specimen represented by fig. 221 is redrawn in this monograph, Pl. LXI, fig. 1a.)

Lingula matthewt Harr, 1878, idem, 3d ed., p. 644, fig. 221. (Copy of Hartt, 1868, p. 644.)

Acrothele matthewi (Hartt), Waucorr, 1884, Bull. U. 8. Geol. Survey No. 10, p. 15, Pl. I, figs. 4 and 4a. (Original
description copied and species discussed. The specimen represented by fig. 4a was labeled by Hartt as “‘Obolus
(Diseina) nitidus,” n. sp., and is redrawn in this monograph, Pl. LXI, fig. 1. Fig. 4 is drawn from the speci-
men figured by Hartt, 1868, p. 644, fig. 221, and is redrawn in this monograph, Pl. LX1, fig. 1a.)

Acrothele matthew (Hartt), Waxcotr, 1886, Bull. U. 8. Geol. Survey No. 30, p. 109. (Mentioned as similar to Acro-
thele subsidua.)

Acrothele matthewi (Hartt), MatrHEw, 1886, Trans. Roy. Soc. Canada for 1885, Ist ser., vol. 3, sec. 4, No. 4, pp. 39-41,
Pl. V, figs. 15 and 15a. (Original description copied and species redescribed and discussed.)

Acrothele matthewi (Hartt), Watcorr, 1891, Tenth Ann. Rept. U. S. Geol. Survey, p. 609. (Mentioned as closely
allied to Acrothele subsidua (White).)

Lingula matthewi Hart, 1891, Acadian Geology, by Dawson, 4th ed., p. 644, fig. 221. (Copy of Hartt, 1868, p. 644.)

Acrothele matthewi (Hartt), Haut and CuarKs, 1892, Eleventh Ann. Rept. State Geologist New York for 1891, Pl. III,
fig. 24. (Fig. 24 is drawn from the specimen figured by Matthew, 1886, Pl. V, figs. 15 and 15a.)

Acrothele matthewi (Hartt), Haut and CuarKe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, pp. 99 and 100,
Pl. IU, fig. 29. (Discussed. Fig. 29 is copied from fig. 24 of the preceding reference.)

Acrothele matthewi (Hartt), MarrHEew, 1895, Trans. New York Acad. Sci. for 1894-95, vol. 14, p. 128, Pl. V, figs. 6a—b.
(No text reference. Figs. 6a—b are copied from Matthew, 1886, Pl. V, figs. 15 and 15a, respectively.)

Acrothele matthewt (Hartt), MarrHew, 1902, Bull. Nat. Hist. Soc. New Brunswick, vol. 14, pt. 5, No. 20, pp. 397 and
402, Pl. XVII, figs. 5a-b. (Mentioned. Figs. 5a-b are copied from Matthew, 1886, Pl. V, figs. 15 and 15a,
respectively.)

Acrothele matthewi (Hartt), MarrHEw, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, p. 104, Pl. V,
figs. 5a-b. (Mentioned. Figs. 5a-b are copied from Matthew, 1902a, Pl. XVII, figs. 5a—b, respectively.)

aThe type locality is unknown. Dayidson’s figure 3 (1863, Pl. XVI] has been designated as the type, but its locality is unknown.

648 CAMBRIAN BRACHIOPODA.

Acrothele matihewi (Hartt), GRABAU and SHimer (in part), 1907, North American Index Fossils, vol. 1, p. 200, fig. 234
(not 234¢). (Described. Fig. 234f is copied from Matthew, 1886, Pl. V, fig. 15; fig. 234 from Matthew’s figure,
1895a, Pl. V, figs. 7a-b, of Acrothele matthewi prima, now referred to Acrothele prima.)

General form subcircular to transversely broad ovate in outline, with the posterior margin
slightly transverse. Ventral valve subconical in young shells, becoming depressed, with an
elevated apex in the adult stages of growth. The apex is within the posterior fourth of the
valve, usually about one-sixth the distance from the posterior to the front margins; it is
formed of two minute, more or less elongated tubercles, with a depression between them at
the posterior end of which a minute pedicle opening occurs; a specimen of the variety Acro-
thele matthewi multicosta Matthew shows a minute tubercle just back of the pedicle opening
that looks as though it were part of a ring that formerly extended about the apex, the two
side tubercles being other portions of the ring. A narrow false area is indicated on some shells;
on others it is absent.

Dorsal valve slightly convex on the umbo, and nearly flat over the anterior portions;
apex marginal as far as can be determined from the compressed shells. The exterior surface
is marked by concentric lines and strize of growth and a few laminated ridges near the outer
margins; on some specimens of the ventral valve one or two low, obscure ridges extend forward
from the apex to the front margin. The epidermal layer is also marked by fine granulations
or papille that are thickly placed over the surface; on the outer portions the granules are
closely spaced on the top of low, irregular, narrow ridges in the same manner as on Acrothele
coriacea Linnarsson; the inner layers of the shell are shiny and marked by concentric lines
and very fine radiating striz.

The shell is corneous and built up of several thin layers or lamelle. A large ventral
valve has a length of 7 mm. with a width of 8 mm.

The interior of the ventral valve shows an apical callosity penetrated by the pedicle open-
ing, and back of it the base of the main vascular sinuses; the latter extend outward and forward
to about the transverse center of the valve, and then forward, curving inward more or less;
rather strong lateral branches extend outward at varying points; one specimen shows three
branches and another seven branches; back of the base of the sinuses a narrow, depressed
space extends to the margin of a very narrow area; these features are shown in a cast of the
interior (Pl. LXI, fig. 1c); the median depressed space corresponds to the false pedicle furrow
in some species of Acrotreta (Pl. LXV, figs. 3g, 3h). The interior of the dorsal valve has a
very characteristic median septum that extends forward from one-fourth to one-half the
length of the valve; also the posterior portions of the main vascular sinuses that originate
in front of the beak and extend outward and then obliquely forward.

Of the muscle scars only the minute umbonal scars of the ventral valve have been observed;
these are minute and close to the anterior end of the false pedicle furrow.

Observations.—In general form and size Acrothele matthewi is allied to A. coriacea Lin-
narsson. The interiors of the valves are also much alike, as may be seen by comparing Plate
LVI, figures 1a-c, with Plate LXI, figures 1c and 1d (ventral valves), and Plate LVI, figure
le, with Plate LXI, figure 1g (dorsal valves). The main vascular sinuses of the ventral valve
of A. matthewi are stronger than those of A. coriacea, and the outer, granular surface of the
epidermal layer is also much coarser. Acrothele matthewr differs from Acrothele (Redlichella)
granulata (Linnarsson) in its smaller size and in the markings on the interior of the ventral
valve; the granulated outer surface of the two species is similar, the differences between them
not being greater than the variations on different portions of the same shell. From A. ava
Matthew and A. proles Matthew this species is separated by the surface characters. It is
difficult to institute detailed comparisons of outline and form of A. matthewi and other species,
as both it and its varieties are represented by compressed and more or less distorted shells.

Acrothele matthewi is a variable species, and Matthew has proposed subspecific names for
the most marked of the varieties. One variety (A. matthewi eryx) is recognized and named
from China. A large form in Matthew’s collection labeled ‘“‘ Acrothele cf. granulata”’ appears

Ee

ACROTRETID. 649

to comprise large shells of A. matthewi. In the larger shells the granules become coarser toward
the outer margins and are more irregularly distributed over the surface.

Of the varieties named by Matthew, “A. matthewi prima” appears to be of specific value
on account of the position of the apex of the ventral valve. ‘‘Acrothele matthewi costata’’ is a
variety of A. prima, and A. matthewi multicostata and A. matthewi lata appear to be the only
varieties remaining that are sufficiently persistent and definite to be recognized, and even
these merge by many gradations into the typical forms of the species.

The specific name was given in honor of Dr. G. F. Matthew.

FORMATION AND LOCALITY.—Upper Cambrian: (3) Shaly limestones 300 feet (91.4 m.) above the Paradozxides zone,
Manuels Brook, Conception Bay, Newfoundland.

Middle Cambrian: (1a, 6n, and 61) Shales near the top of No. 6; (1) shales of zone A of No. 7; and (2) shales of
zone B of No. 7; all in the Manuels Brook section [Walcott, 1891b, p. 261] on Manuels Brook, Conception Bay, New-
foundland.

(6g) Limestone near the base of the Middle Cambrian, the lowest horizon carrying Paradoxides, northwest side of
Chapple Arm Harbor, about 1 mile (1.6 km.) from its head, Trinity Bay, Newfoundland.

(21 and 2m) Limestones and shales at the base of the Paradoxides zone [Matthew, 1895a, p. 108] on Hanford Brook;
(301h [Matthew, 1886, p. 41])shales of Division 1c of Matthew, on Hanford Brook; (301i) beds of Division 1b1 of Matthew,
on Hanford Brook; (3011 [Matthew, 1886, p. 41]) shales of Division 1d of Matthew, on Porters Brook, St. Martins; (301g
[Matthew, 1886, p.41])¢ sandstones of Division 1c of Matthew, at Portland (now part of the city of St. John); (2s)
limestone in upper part of Paradowides zone, at Hastings Cove [see Matthew, 1898b, p. 38], on Kennebecasis Bay, 0.5
mile (0.8 km.) northeast of Torryburn, on the Intercolonial Railway, northeast of St. John; (3b) shale at the base of
the Paradoxides zone, at the head of Seeley Street, St. John; (301k [Walcott, 1884a, p.16]) shales of the St. John forma-
tion at St. John; and (801j [Walcott, 1884a, p. 16]) shales of the St. John formation at Ratcliffs Millstream; all in
St. John County, New Brunswick.

y, ACROTHELE MATTHEWI ERYX Walcott.
Plate LXI, figure 2.
Acrothele matthewi eryx Waxcott, 1905, Proc. U. S. Nat. Mus., vol. 29, p. 11. (Described and discussed as below asa
new variety.)

In form, convexity, and size the ventral valve of the only specimen representing this
variety is very similar to the typical forms of Acrothele matthewi (Hartt). The shell is partly
exfoliated and shows a small oval pit about the pedicle opening and two narrow vascular
sinuses that extend from a point nearly back of the pit about the pedicle opening, forward, and
a little outward, about one-third the length of the valve.

The shell is built up of several layers or lamellz that are smooth and shiny on the interior,
except where shghtly roughened by faint vascular markings and obscure radiating striz; the
outer surface is dull and spanked! by concentric striz and lines of growth, and numerous ‘fine,
irregular, often anastomosing, elevated lines that give the surface a rough appearance.

The ventral valve is neeally circular, with a diameter of 6mm. If this shell were associated
with Acrothele matthewi in the Middle Cambrian rocks of New Brunswick, I should not hestitate
to identify it with that species. In the absence of a series of specimens, and of representatives
of the dorsal valve, it is not certain that it is identical with Acrothele matthew.

FoRMATION AND LOCALITY.—Middle Cambrian: (C4) Limestone nodules at the base of the lower shale member of

the Kiulung group [Blackwelder, 1907a, pp. 37 and 40 (2d list of fossils), and fig. 10 (bed 4), p. 38], 3 miles (4.8 km.)
southwest of Yenchuang, Sintai district, Shantung, China.

ACROTHELE MATTHEWI LATA Matthew.

Plate LXI, figure 3.

Acrothele matthewi lata MatrHEw, 1886, Trans. Roy. Soc. Canada for 1885, Ist ser., vol. 3, sec. 4, No. 4, p. 41, Pl. V,
figs. 17 and 17a. (Described asa new variety. The specimen represented by figs. 17 and 17a is redrawn in this
monograph, Pl. LXI, fig. 3.)

Acrothele matthewi lata Matthew, Hai and CrarKe, 1892, Eleventh Ann. Rept. State Geologist New York for 1891,
Pl. III, figs. 25and 26. (Fig. 26 is drawn from the specimen figured by Matthew, 1886, Pl. V, figs. 17 and 17a.)

a This species also occurs in Locality 308h.

650. CAMBRIAN BRACHIOPODA.

Acrothele matthewi lata Matthew, Hatt and CrarKeE, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, Pl. III,
figs. 26-28. (Notextreference. Figs. 27 and 28 are drawn from the specimen figured by Matthew, 1886, Pl. V,
figs. 17and 17a. Figs. 26and 27 are copied from figs. 25 and 26, respectively, of the preceding reference.)

Acrothele matthewi lata MattHEWw, 1895, Trans. New York Acad. Sci. for 1894-95, vol. 14, Pl. V, figs. 8a-b. (No text
reference. Figs. 8a—b are copied from Matthew, 1886, Pl. V, figs. 17 and 17a, respectively.)

Acrothele matthewi lata MattHEWw, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, p. 104, Pl. V,
fies. Ga-b. (Mentioned. Figs. 6a—b are copied from Matthew, 1902a, Pl. XVII, figs. 6a—b, respectively.)

This variety is characterized by having a flatter rim that gives the valves a depressed
appearance around the border. There are many variations that tend to unite it with typical
examples of the species, but there is no difficulty in recognizing the typical forms of the variety.

FoRMATION AND LOCALITY.—Middle Cambrian: (301 [Matthew, 1886, p. 42]) Sandstones of Division 1b2 of Mat-
thew, on Hanford Brook; (301a[ Matthew, 1895a, Pl. V, fig. 8]) fine-grained sandstones below the Protolenus-bearing shales
and sandstones in Division 163 of Matthew, on Hanford Brook; and (301g {[Matthew, 1886, p. 41]) sandstones of Division
1c of Matthew, at Portland (now a part of the city of St. John); all in St. John County, New Brunswick.

ACROTHELE MATTHEWL MULTICOSTATA Matthew.

Plate LXI, figures 5, 5a-c.

Acrothele matthew multicostata MattHEW, 1897, Trans. Roy. Soc. Canada for 1897, 2d ser., vol. 3, sec. 4, No. 7, p. 168.
(Characterized as a new variety.)

This variety is distinguished from the typical forms of the species by the presence of
numerous narrow, more or less obscure, radiating ribs. There is a gradation in this respect
to typical forms of A. matthewi, where an occasional trace of ribs occur. The more anterior
position of the apex of the ventral valve serves to distinguish this variety from A. prima costata,
which occurs at a slightly lower horizon at the same locality.

This form owes its varietal name to the numerous radiating ribs upon its shell surface.

FoRMATION AND LOCALITY.—Middle Cambrian: (2s and 2t) ¢ Shales and interbedded limestone im the upper part
of the Paradoxides zone, Hastings Cove | Matthew, 1898b, p. 38], on Kennebecasis Bay, 0.5 mile (0.8 km.) northeast of

Torryburn, on the Intercolonial Railway, northeast of St. John; and (21) limestone at the base of the Paradowides zone
[Matthew, 1895a, p. 108], on Hanford Brook; both in St. John County, New Brunswick.

ACROTHELE? minuTA Walcott.

Plate LXIII, figure 3.
Acrothele? minuta Watcott, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 303. (Described as below as a new species.)

Shell mmute, 1.5 mm. in diameter, subcircular in outline, gently convex, with a slight
median depression from the umbo to the anterior margin; back of the umbo there is a sharp
median depression between minute ridges on each of which there are two points or nipples.
Surface marked by fine concentric striz. Substance of shell apparently phosphatic.

This interesting little species is represented by a single specimen. ‘The generic reference
is somewhat doubtful.

FoRMATION AND LocALITy.—Middle Cambrian: (C6) Thin slabby limestone in the upper shale member of the

Kiulung group [Blackwelder, 1907a, pp. 37 and 41 (2d list of fossils), and fig. 10 (bed 12), p. 38], 2.5 miles (4 km.)
southwest of Yenchuang, Sintai district, Shantung, China.

ACROTHELE NITIDA (Ford).

Plate LVIII, figures 4, 4a.

Obolella nitida Ford, 1873, Am. Jour. Sci., 3d ser., vol. 5, p. 213. (Described as on p. 651 as a new species.)

Obolella nitida Ford, Watcorrt, 1886, Bull. U. 8. Geol. Survey No. 30, pp. 118-119, Pl. XI, fig. 2. (Original descrip-
tion copied. The specimen represented by fig. 2 is redrawn in this monograph, Pl. LVIII, fig. 4.)

Obolella nitida Ford, Waucorr, 1891, Tenth Ann. Rept. U. S. Geol. Survey, p. 612, Pl. LXXII, fig. 1. (New localities
mentioned. Figure copied from preceding reference.)

Obolella nitida Ford, Hatt and CuarKe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, p. 70. (Mentioned.)

@2t is the type locality, though the specimens in the United States National Museum collections to which that number is assigned were
collected later than Matthew’s type specimens.

ACROTRETID”. ; 651

Linnarssonia? nitida (Ford), Waucorrt, 1901, Proc. U. S. Nat. Mus., vol. 23, p. 673. (Merely changes generic.reference.)
Obolella nitida Ford, GRaBAv and Sumer, 1907, North American Index Fossils, vol. 1, p. 189, fig. 223c. (Described.
Fig. 223c is copied from Walcott, 1886, Pl. XI, fig. 2.) :

The original description by Ford follows:

Shell transversely suboval, small. Dorsal vaive gently but irregularly convex, the greatest elevation occurring
at a point about one-fifth the length of the valve from the apex. From this point the beak curves sharply down to
the hinge line, which it almost touches. The hinge line itself is slightly curved and apparently equal to about one-
third the width of the shell. At the most elevated point of the valve commences a well-defined median depression,

-which extends forward for a distance of about one-half the length of the valve, gradually widening and becoming
more shallow until it disappears. A portion of the dorsal valve close to the margin is sometimes nearly flat all around.
The internal markings are not well enough shown in any of the specimens that I have seen to admit of description.
The surface is ornamented with very fine concentric strize and numerous close set radiating striz, the whole just visible
to the unassisted eye.

The ventral valve is not certainly known. The width of the largest dorsal valve that I have seen is 0.14 of an
inch and the length 0.1 of an inch.

Through the courtesy of Prof. J. M. Clarke I have had the opportunity of studying the
type material of this species, now in the New York State Museum collections. There are
four specimens of the dorsal valve and one representing the ventral valve. The reference
to Obolella (Ford, 1873, p. 213] and Linnarssonia [Walcott, 1901, p. 673] is incorrect. The
shell is lke that of Acrothele and the matrix representing the ventral valve shows all the
characters of Acrothele as far as any characters are shown at all. The slope of the valve toward
an eccentric apex is indicated im the same manner as in Acrothele matthewi (Hartt).

The only difference detected between this shell and young shells of Botsfordia celata
(Hall) is the absence of the characteristic pustulose surface of the latter. Five of Mr. Ford’s
specimens appear to have come from the same piece of limestone, and nothing that can be
identified as the same species has been found in the large collection Tinale at the same locality.

The largest shell has a diameter of 3mm. The surface is marked by fine concentric striz,
and sharp, interrupted, radiating lines.

FORMATION AND LOCALITY.—Lower Cambrian: (27) Even-bedded and conglomerate limestones on the ridge in the

eastern suburb of Troy, Rensselaer County; and (22) limestone 1.5 miles (2.4 km.) north of North Granville, Fort Ann
quadrangle (U. 8. Geol. Survey), Washington County; both in New York.

ACROTHELE PANDERI n. Sp.

“

Plate LiX, figures 5, 5a-c.

This species is of the same general type as Acrothele colleni n. sp. It differs in having
a less elevated and more posterior apex on the ventral valve, and the finer granulation of the
exterior of the shell; also in the presence of a median depression or sinus on the dorsal valve.

The surface is more like that of Acrothele (Redlichella) granulata (Linnarsson) as the granu-
lation, although of the same type as that on A. coriacea Linnarsson and A. colleni, has more
the appearance of an epidermal granulated layer.

The description of A. collent applies to this shell with the exceptions mentioned, and a
few other details. It also reaches a somewhat larger size. One specimen of the seminal valve
has a transverse diameter of 11 mm., with a length of 9 mm. Another example of the same
valve has an equal length and breadth; usually the dorsal valve is a little broader than long,
and it is marked by a clearly defined median depression that extends from the beak forward,
gradually widening to the front margin. The apex of the ventral valve has a minute tubercle
on each side, with a small pedicle opening on the slope just back of the tubercles, in this respect
closely resembling the apex of A. coriacea.

The interior of the ventral valve shows a thickening of the shell under the short visceral
area in front of the pedicle opening; the main vascular sinuses appear to originate beside or a
little in advance of the pedicle opening and extend forward, gradually separating, but occupy-
ing a position about halfway between the margins and the median line.

652 CAMBRIAN BRACHIOPODA.

The specific name is given in honor of Dr. C. H. Pander.

FoRMATION AND LOCALITY.—Lower Cambrian: (4v) About 200 feet (61 m.) above the unconformable base of the
Cambrian and 75 feet (22.9 m.) above the top of the quartzitic sandstones in a shale which corresponds in stratigraphic
position to shale No. 6 of the Dearborn River section [ Walcott, 1908f, p. 202], Gordon Creek, 6 miles (9.6 km.) from South
Fork of Flathead River, Ovando quadrangle (U. S. Geol. Survey); and (5j) the same stratigraphic horizon as 4v, about
6 miles (9.6 km.) west-northwest of Scapegoat Mountain, on the Continental Divide between Bar Creek and the
headwaters of the south fork of North Fork of Sun River, Coopers Lake quadrangle (U. 8. Geol. Survey); both in
Powell County, Montana.

ACROTHELE PRETIOSA (Billings).

Plate LVIII, figures 1, la-g.

Obolella pretiosa Brtines, 1862, Geol. Survey Canada, Paleozoic Fossils, vol. 1, pp. 68-69, figs. 6la—b. (Described
and discussed as a new species. )

Obolella pretiosa Buurnes, 1863, Geol. Survey Canada, Fifteenth Rept. Progress, p. 230, figs. 239a—b. (No text refer-
ence. Figures are copied from preceding reference.)

Obolella pretiosa Billings, CHarmaN, 1863, Canadian Jour. Industry, Sci., and Art, new ser., vol. 8, p. 191, fig. 160b.

Obolella pretiosa Billings, CoapmMan, 1864, Minerals and Geology of Canada, p. 163, fig. 160b. (Copy of preceding
reference.) :

Obolella? pretiosa Billings, Waucorr, 1886, Bull. U. S. Geol. Survey No. 30, p. 111. (Generic relations mentioned.)

Billingsia pretiosa (Billings), Forp, 1886, Am. Jour. Sci., 3d ser., vol. 31, p. 467. (Merely changes generic reference.)

Elkania pretiosa (Billings), Forp, 1886, idem, vol. 32, p. 325. (Merely changes generic reference.)

Not Obolella (Linnarssonia) pretiosa Dawson, 1890, Trans. Roy. Soc. Canada for 1889, Ist ser., vol. 7, sec. 4, No. 3,
pp. 53-54, figs. 26a-c. (Referred in this monograph to Acrotreta sagittalis.)

Not Linnarssonia pretiosa Haut and CLARKE, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, p. 70, Pl. III,
figs. 43-44. (Referred in this monograph to Acrotreta sagittalis.)

Linnarssonia pretiosa ScHucHERT (in part), 1897, Bull. U.S. Geol. Survey No. 87, p. 262. (Mere reference, but includes
specimens referred to both Acrotreta sagittalis and Acrothele pretiosa.)

Acrothele pretiosa (Billings), Waxcort, 1898, Proc. U. S. Nat. Mus., vol. 21, p. 402. (Merely changes generic reference.)

Linnarssonia pretiosa (Billings), Waxcorr, 1901, Proc. U. S. Nat. Mus., vol. 23, p. 673. (Merely changes generic
reference. )

2Linnarssonia pretiosa GRABAU and SuimeER, 1907, North American Index Fossils, vol. 1, p. 200. (Described, but not
figured, and it is impossible to tell whether the authors are discussing the Linnarssonia pretiosa that is now
referred to Acrotreta sagittalis or the true Acrothele pretiosa.) ;

General form transversely oval; convexity unknown, as all specimens are more or less
flattened in the shale. Ventral valve with the apex near the posterior margin; pedicle aperture
small, and at the apex, but whether on its posterior slope or summit can not be determined.
Dorsal valve with the beak marginal, and greatest elevation on the umbo on the posterior third
of the valve. :

Surface marked by numerous concentric lines and strize of growth and a varying number
of irregular, low, narrow, more or less interrupted, radiating ribs; in addition there is a minutely
roughened surface formed by very fine, irregular, elevated lines that have minute granules upon
them; this results in a surface much like that of Acrothele matthewr (Hartt).

The average diameter of the larger specimens is 5 mm., though there are many less than
2 mm. across.

The cast of the interior of a ventral valve shows the cast of a small oval apical callosity;
the interior of the dorsal valve has a narrow median ridge that extends forward to the anterior
fifth of the length of the valve; the main vascular sinuses are narrow and have the usual direc-
tion from the median line near the posterior margin outward and then obliquely forward. The
only muscle scars observed are the cardinal scars on each side of the median ridge between the
main vascular sinuses and the posterior margin, and the elongate oval central scars in advance
of the transverse center of the valve.

Observations—Owing to the compressed and more or less distorted condition of the speci-
mens representing this species, it is difficult to give an accurate description of it. The posterior
position of the apex of the ventral valve, concentrically striated surface, long median ridge in
dorsal valve, and position of central scars, give the species an assemblage of detailed characters
unknown in other species of the genus.

FORMATION AND LOCALITY.—Ordovician: (220a) Shales of the ‘‘Upper Sillery’’ (Lawzon of Logan), on Chaudiere
River at the Grand Trunk railroad bridge; and (319¢ [Billings, 1862b, p. 69]) shales at Cape Rouge, above Quebec;
both in the Province of Quebec, Canada.

ACROTRETIDZ. 653

(48) Shales on the summit of Moses Hill, 2 miles (3.2 km.) west of North Greenwich; and (338i) shales 1 mile (1.6
km.) west-northwest of South Argyle; both near the line between the Schuylerville and Cambridge quadrangles (U. 8.
Geol. Survey), Washington County, New York.

(838z) Limestone on the north side of Bald Mountain, about 2 miles (3.2 km.) northwest of Greenwich, Schuyler-
ville quadrangle (U. S. Geol. Survey), Washington County, New York.

ACROTHELE PRIMA (Matthew).

Plate LXI, figures 6, 6a-b; Plate LXII, figure 2.

Acrothele matthewi prima MartHEw, 1886, Trans. Roy. Soc. Canada for 1885, Ist ser., vol. 3, sec. 4, No. 4, p. 41, Pl. V,
figs. 16 and 16a. (Characterized. The specimen represented by figs. 16 and 16a is redrawn in this monograph,
Pl. LXI, fig. 6.)

Acrothele matthewi prima Matthew, Hatt and CrarKe, 1892, Eleventh Ann. Rept. State Geologist New York for 1891,
Pl. III, fig. 27. (Fig. 27 is drawn from the specimen represented in Matthew, 1886, Pl. V, figs. 16 and 16a.)

Acrothele matthew prima Matthew, Hatt and CrarKe, 1892, Nat. Hist. New York, Paleontology, voi. 8, pt. 1, Pl. III,
fig. 25. (No text reference. Fig. 25 is copied from fig. 27 of the preceding reference.)

Acrothele matthewi prima MartaEw, 1895, Trans. New York Acad. Sci. for 1894-95, vol. 14, Pl. V, figs. 7a-b. (No text
reference. The figures are drawn from the specimen represented in Matthew, 1886, Pl. V, figs. 16 and 16a.)

Acrothele matthewi prima MartHew, 1902, Bull. Nat. Hist. Soc. New Brunswick, vol. 4, pt. 5, No. 20, pp. 397 and 402,
Pl. XVII, figs. 4a-b. (Mentioned. The figures are copied from figs. 7a-b, respectively, of the preceding
reference. )

Acrothele matthewi prima MatrHEw, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, p. 104, Pl. V,
figs. 4a-b. (Mentioned. Figs. 4a—b are copied from Matthew, 1902a, Pl. XVII, figs. 4a—b, respectively.)
Acrothele matthewi GRABAU and SuHimer (in part), 1907, North American Index Fossils, vol. 1, p. 200, fig. 234g (not
234f). (Described. Fig. 234g is copied from Matthew’s figure, 1895a, Pl. V, figs. 7a—b, of Acrothele matthewi

prima. The specimen represented by fig. 234f belongs with Acrothele matthew, which see, p. 648.)

This species is distinguished from Acrothele matthew: (Hartt) by the apex of the ventral
valve being almost directly over the posterior margin instead of from one-fifth to one-sixth the
length of the valve from it. It has a finely granulated surface of the same type as that of
A. matthewi and the valves are similar in outlme except near the apex of the ventral valve.
The average size of this species is a little less than that of A. matthew.

The variety costata was separated by Matthew [1895a, p. 128] on account of the presence of
six or more ribs; this character is an exceedingly variable one and of little value, as the ribs
vary from a faint trace to twenty or more ribs, but as it has been used the varietal name is
retained.

FORMATION AND LOCALITY.—Middle Cambrian: (2g)¢@ Sandstones of Division 1b1; (2f) sandstones 3 feet below
2g in Division 1b1; (2h) sandstones of Division 1b2; and (2i) sandstones of Division 1b3; all in Matthew’s [1895a, p.
108] Protolenus zone, Hanford Brook, St. John County, New Brunswick.

(13t) Sandstones at the base of Division Elb; and (13d’’) sandstones 10 feet (3 m.) below Division E2a; both in
Matthew’s [1903, p. 21] Etcheminian, Dugald Brook, Indian River, eastern Cape Breton, Nova Scotia.

ACROTHELE PRIMA CosTATA (Matthew).

Plate LXI, figures 4, 4a—d.

Acrothele matthew costata MatrHmw, 1895, Trans. New York Acad. Sci. for 1894-5, vol. 14, p. 128, Pl. V, fig. 9.

(Characterized as a new variety.)

Acrothele matthewi costata MattHEw, 1902, Bull. Nat. Hist. Soc. New Brunswick, vol. 4, pt. 5, No. 20, p. 397, Pl. XVI,
fig. 6. (Mentioned. Fig. 6 is copied from fig. 9 of the preceding reference.)
Acrothele matthewi costata MattHEw, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, p. 104, Pl. IV,

fig. 6. (Mentioned. Fig. 6 is copied from Matthew, 1902a, Pl. XVI, fig. 6.)

Matthew [1895a, p. 128] separated this variety on account of the presence of six or more
broad, radiating ribs that are not contimuous, but that are interrupted by some of the strong
lines of growth; the ribs do not occur on very young shells or near the umbo of the old shells.
The surface of the epidermal layer is granulated in the same manner as the typical forms of
A. matthewi (Hartt).

a 2e is the type locality, though the specimens in the United States National Museum collections to which that number is assigned were
collected later than the type specimens.

654. CAMBRIAN BRACHIOPODA.

The variation in the strength and number of ribs is from a slight trace of one or two short
ribs near the front margin to twenty or more ribs. One extreme is represented (Pl. LXI) by
figure 4a, and the other by figure 4. The specimens illustrated are from the same layer of
rock. A. matthewi multicostata Matthew is similar to A. prima costata in surface characters
and the presence of radiating ribs, bu. it differs in the more anterior position of the apex on
the ventral valve.

The variety costata occurs in association with A. prima and is distinguished from it by
the presence of more or less distinctly indicated ribs.

FoRMATION AND LOCALITY.—Middle Cambrian: (2h) Sandstones of Dwision 162; (801d [Matthew, 1895a, p. 128])
sandstones of Division 1b5;¢ (2i) sandstones of Division 1b3; and (2k) just above 2i, in the sandstones of Division
1b3; all in Matthew’s [1895a, p. 108] Protolenus zone, Hanford Brook, St. John County, New Brunswick.

(3011 [Matthew, 1895a, p. 128]) Sandstones of Division 1d at Porters Brook, St. John County; and (801i [Matthew,
1895a, p. 128]) sandstones of Division 1b5 of Matthew’s Protolenus zone, at Catons Island, Long Reach, St. John
River, Kings County; all in New Brunswick.

(6n) Shales near the top of No. 6 of the Manuels Brook section [ Walcott, 1891b, p. 261], Manuels Brook, Concep-
tion Bay, Newfoundland.

ACROTHELE PRIM@VA (de Verneuil and Barrande).

Plate LVII, figure 6.

Discina (Orbicula) primeva DE VERNEUIL and Barranpe, 1860, Bull. Soc. géol. France for 1859-60, 2d ser., vol. 17,
p. 532, Pl. VIII, figs. 2 and 2a. (Described and discussed in French as a new species. Figs. 2 and 2a are
reproduced in this monograph, Pl. LVII, figs. 6 and 6’, respectively.)

Acrothele primeva (de Verneuil and Barrande), Pomprcxs, 1896, Jahrb. K.-k. geol. Reichsanstalt for 1895, Bd. 45,
Hit. 3, p. 6038. (Discussed in German.)

This species appears to have been represented by only the ventral valve; this, the authors
state, is corneous, slightly convex, and ornamented by very fine concentric strie, and three
fine lines that radiate from the apex to the front margin. On the figure the apex is about one-
third the distance from the posterior to the anterior margin, and a faint false area is indicated
by lines that diverge from the apex to the posterior margin.

As far as can be determined from the illustrations and descriptions of the two species,
this form is most nearly related to Acrothele quadrilineata Pompecky.

FoRMATION AND LOCALITY.—Middle Cambrian: (350 [de Verneuil and Barrande, 1860, p. 588]) Red limestone ~

of the Paradoxides zone, near Adrados, north of Sabero and Bofar, Cantabrian Mountains, Province of Leon. north-
western Spain.

ACROTHELE PROLES Matthew.

Plate LXII, figures 3, 3a-e, 4, 4a.

Acrothele proles MattHEw, 1902, Bull. Nat. Hist. Soc. New Brunswick, vol. 4, pt. 5, No. 20, pp. 400-401, Pl. XVII,
figs. 3a-e. (Described and discussed as a new species. The specimen represented by fig. 3a is redrawn in
this monograph, Pl. LXII, fig. 4. Fig. 4a is drawn from one of Matthew’s (unfigured?) specimens.)

Acrothele proles MattHEw, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, p. 60. (Notes on
orientation.)

Acrothele proles MattHEW, 1903, idem, pp. 102-103, Pl. V, figs. 3a-e. (Description and figures copied from Matthew,
1902a, pp. 400-401, Pl. XVII, figs. 3a-e.)

The most essential difference between this species and Acrothele avia Matthew is in the
position of the apex of the ventral valve. There are certain minor differences in the visceral
callosity, but these are variable and depend more or less upon the state of preservation of
the shell. Nearly all the shells of Acrothele from the shales and arenaceous beds of the Nova
Scotia localities have been distorted by flattening or lateral movement; on this account when
one has but a few specimens it is difficult to place confidence on characters subject to change
by very slight distortion of the shell. ©

a On the description of Plate V [Matthew, 1895a} Matthew says that the type specimen is from divisions 1b2 and 1b5; there is hut one type
specimen and it can not be ascertained to which of the two divisions it should be assigned. The specimens in the United States National
Museum collections from Locality 2h were collected later than the time at which Matthew made his collections.

<_<

ACROTRETIDA. 655

Acrothele proles has the same type of surface as A. avia, also a strong shell that is often
thickened in the vicinity of the apex; the number and strength of the radiating ridges vary
with the thickness of the shell and the manner in which it has been compressed laterally.

The position -of the apex of the ventral valve varies a little, but on the average it is nearer
the posterior margin than in A. avia and not so near as in A. prima (Matthew).

FoRMATION AND LocaLity.—Middle Cambrian: (18m) Sandstones of Division E3f in Matthew’s [1903, p. 76]
Eicheminian, on Gillis Brook, Indian River; and (131) shaly sandstones of Division E3a; and (13n) sandstones of
Division E3f; both in Matthew’s [1903, p. 21] Etcheminian, on Dugald Brook, Indian River; all in eastern Cape
Breton, Nova Scotia.

ACROTHELE QUADRILINEATA Pompeckj.

Plate LVII, figure 5.

Acrothele quadrilineata Pomprcxs, 1896, Jahrb. K.-k. geol. Reichsanstalt for 1895, Bd. 45, Hft. 3, p. 511, Pl. XIV,
figs. 6a-c. (Described and discussed in German as a new species; see below for liberal translation. Figs. 6b
and 6c are reproduced in this monograph, Pl. LVII, figs. 5 and 5’, respectively.)

The original description by Pompeckj follows:

Ventral valve subcircular in outline; length, 7 mm.; width, 7.8 mm.; posterior margin slightly transverse.
Apex low and about 2 mm. from the posterior margin; details of apex unknown; false area narrow and indefinitely
defined from the apex to the posterior margin. ‘our flat ridges radiate from the apex toward the front margin. Surface
marked by strong, closely arranged, concentric lines that under the microscope show very indistinct granulations.

Dorsal valve unknown. !

Pompeckj states [1896b, p. 511] that the ventral valve of this species is more arched than
that of Acrothele coriacea Linnarsson. It is evidently a form closely allied to the latter and
also to Acrothele bohemica (Barrande), which occurs at the same stratigraphic horizon in the
**Paradouides green slate.”

ForMATION AND LOCALITY.—Middle Cambrian: (345d [Pompeckj, 1896b, p. 511]) Shales of Paradoxides zone,
Forester house of Slapy (Buchava quarry), Skrej, Bohemia.

ACROTHELE RARA Walcott.

Plate LXIII, figures 4, 4a.

Acrothele rarus Watcott, 1905, Proc. U. S. Nat. Mus., vol. 28, pp. 303-304. (Described and discussed as below as a
new species.)

Of this shell only the interiors of the valves are known. Shells of average size are about
3.5 mm. in diameter. The outline of the valves is subcircular, the transverse diameter being
slightly more than the length of the valve.

The interior of the ventral valve shows that the valve was moderately convex, with a
perforated apex about half a millimeter from the posterior margin. A short, broad median
ridge extends for a short distance in front of the foraminal opening, and short, narrow ridges
extend obliquely forward from each side of the opening. What may be lateral muscle scars
occur close to the posterolateral margins. In the dorsal valve a strong median ridge extends
from the posterior margin to the center of the valve; this ridge is angular at the summit and
broadest toward its anterior end. A vascular sinus starts on each side of the base of the
median ridge and extends obliquely forward.

The dark interior surface of the valves is marked by concentric lines that give a somewhat
laminated appearance to the surface. From the manner in which the shell adheres to the
limestone matrix it is probable that its outer surface is roughened by raised lines, somewhat
as on Acrothele subsidua (White).

The data for comparison of this species with described species from America and Europe
are too limited to be of value. A comparison with Acrothele (Redlichella) granulata (Linnarsson),
of the Salt Range, India, shows a strong similarity in the interiors of the valves, but I do not

213m is the type locality, though the specimens in the United States National Museum collections to which that number is assigned were
collected later than the type specimens.

656 CAMBRIAN BRACHIOPODA.

think that it is probable that the two forms are specifically identical, as the interiors of the
valves of several species of Acrothele appear very much alike.

ForRMATION AND LOCALITY.—Middle Cambrian: (€57) Limestone nodules in the lower shale member of the
Kiulung group [Blackwelder, 1907a, pp. 37 and 40 (first list of fossils)], 3 miles (4.8 km.) south of Kaokiapu and
about 4 miles (6.4 km.) north of Sintaihien, Sintai district; and (€23) upper part of thin-bedded gray oolitic lime-
stone at the base of the Changhia formation [Blackwelder, 1907a, p. 32 (list of fossils), and fig. 6 (bed 20), p. 25], 50
feet below the base of the cliffs 1 mile (1.6 km.) east-southeast of Changhia; both in Shantung, China.

ACROTHELE SPURRI Walcott.

Plate LX, figures 3, 3a-c.

Acrothele subsidua Watcort (in part) [not Warre], 1886, Bull. U.S. Geol. Survey No. 30, p. 109, Pl. IX, fig. 4 (mot figs.
4a-c). (Locality mentioned in discussion of A. swbsidua. The specimen represented by fig. 4 is redrawn in
this monograph, Pl. LX, fig. 3. Figs. 4a-c belong with Acrothele subsidua.)

Acrothele subsidua Waucort (in part) [not WxrTE], 1891, Tenth Ann. Rept. U.S. Geol. Survey, p. 608, Pl. LXX, fig. 1
(not figs. la-c). (Mentioned. Fig. 1 is copied from fig. 4 of preceding reference. Figs. la-c belong with
Acrothele subsidua.)

Acrothele subsidua Walcott, MatrHEw, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, p. 103. (Dis-
cussed as possible new species.)

Acrothele spurri Waxcorr, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, pp. 86-87, Pl. VIII, fig. 14. (Described and
discussed as below as a new species. Fig. 14 is a revised drawing of the specimen represented by fig. 4 of the
preceding reference. Fig. 14 is copied in this monograph, Pl. LX, figs. 3, 3a-b.)

General form transversely ovate. Ventral valve depressed with an elevated apex a little
in front of the posterior margin; from the apex the surface slopes rapidly and then gradually
to the front margin, and quite rapidly to the posterior margin; the posterior margin arches
up from the plane of the sides of the valves about one-half the height of the apex and gives to the
valve the appearance of being pushed up so as to throw the apex toward the front; a minute
pedicle opening truncates the apex at its posterior side; a small, subtriangular, convex false
area extends from just back of the apex to the posterior margin.

Surface of the epidermal layer marked by fine, concentric strie of growth and a very
minute granulation; the imner laminations of the shell are shy and marked by numerous
radiating strize and a few concentric les. Shell corneous and built up of numerous layers or
lamelle more or less oblique to the outer layer.

Dorsal valve and interior of valves unknown. The largest ventral valve has a length of
6 mm.; width, 7 mm.

Observations.—This very striking species is associated with Acrotreta primeva Walcott and
Olenellus gilberti Meek, in the upper portion of the Olenellus zone of central Nevada. Some
fragmentary specimens of this species were referred by me [1886b, p. 109] to Acrothele subsidua
(White), but with better material and more thorough study, the Lower Cambrian specimens are
referred to A. spurrt. A. spurri differs from A. subsidua in the more posterior position of its
apex, in its convex, distinctly marked false area; in its strongly arched posterior margin; and
in its more finely granulated surface. The convex false area and arched posterior margin are
features also seen in A. woodworthi of the Lower Cambrian (Pl. LX, fig. 6).

The specific name is given in honor of Mr. J. E. Spurr.

FoRMATION AND LOCALITY.—Lower Cambrian: (31a) Limestone and interbedded siliceous shales of the Pioche formation

[ Walcott, 1908a, p. 11], just above the quartzite on the east side of the anticline, near Pioche, Lincoln County, Nevada.

Specimens that are somewhat doubtfully referred to Acrothele spurri Walcott occur at the
following locality:

Lower Cambrian: (11) Shales of No.3 of the Silver Peak group [Walcott, 1908f, p. 189], 2.5 miles (4 km.) south of
Barrel Spring and 0.5 mile (0.8 km.) east of the road, in the extreme southeastern corner of the Silver Peak quadrangle
(U. S. Geol. Survey), Esmeralda County, Nevada.

ACROTHELE SuBSIDUA (White).

Plate LX, figures 1, la-o, 8.

Acrotreta? subsidua Wurre, 1874, U. S. Geog. Surveys W. 100th Mer., Prelim. Rept. Invertebrate Fossils, p. 6.
; (Described as a new species.)

ACROTRETIDZ. 657

Acrotreta ? subsidua Waite, 1877, U.S. Geog. Surveys W. 100th Mer., vol. 4, pt. 1, pp. 34-36, PI. I, figs. 3a-d. (Described
essentially as in preceding reference and discussed. The specimens represented by figs. 3a and 3d are redrawn
in this monograph, Pl. LX, figs. 1 and In, respectively.)

Acrothele subsidua Waite, 1880, Proc. U. S. Nat. Mus., vol. 3, p. 47. (Merely changes generic reference.)

Acrothele subsidua (White), WaAxcorr (in part), 1886, Bull. U. S. Geol. Survey No. 30, pp. 108-109, Pl. IX, figs. 4a-c
(not fig. 4). (Original description copied, but the paragraph added on p. 109 includes reference to specimens
now referred to Acrothele spurri. Figs. 4a-c are drawn from the specimens figured by White, 1877, Pl. I, figs.
3a-d. Fig. 4 is now referred to Acrothele spurri.)

Acrothele subsidua (White), Waxcorr (in part), 1891, Tenth Ann. Rept. U. 8. Geol. Survey, pp. 608-609, Pl. LXX,
figs. la—c (not fig. 1). (The text reference mentions this species together with specimens which are now referred
to Acrothele spurri. Figs. la-c are copied from Walcott, 1886b, Pl. IX, figs. 4a-c, respectively. Fig. 1 is now
referred to Acrothele spurt.)

Acrothele subsidua (White), BrEcHER, 1891, Am. Jour. Sci., 3d ser., vol. 41, Pl. XVII, fig. 12. (No text reference.)

Acrothele subsidua (White), Hart and Ciarxe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, pp. 100 and
103, Pl. III, figs. 30 and 31. (Mentioned.)

Acrothele subsidua (White), Marrarw, 1902, Trans. Roy. Soc. Canada for 1902, 2d ser., vol. 8, sec. 4, No. 3, p. 110.
(Specimens from new locality characterized.) :

Acrothele subsidua (White), GRABAU and Sumer, 1907, North American Index Fossils, vol. 1, p. 200, figs. 234d-e,
p. 199. (Described. Figs. 234d—e are copied from Walcott, 1886b, Pl. IX, figs. 4a—b, respectively.)

General form subcircular to transversely broad oval in outline with the posterior margin
broadly rounded to slightly transverse in the dorsal valve. Ventral valve slightly convex
toward the apex, with the apex between the posterior one-fifth to one-third the distance from
the front to the back margin. The apex when perfect is formed of two minute elongate tuber-
eles with a narrow elongate depression between them; the size and form of the tubercles and
depression between them varies; in some specimens the tubercles are united in front, and in
others there is a third minute tubercle just back of the apical depression. A pedicle opening
varying from a minute circular to a small elongate-ovate aperture, narrow in front, occurs at
the posterior end of the apical depression; it may have its narrow end well between the elongate
tubercles or back of them. A triangular false area is well defined on some shells, and very
obscure on others; it is often divided midway by an elevated line which in some examples is
a narrow rounded ridge extending from just back of the pedicle opening to the posterior margin;
the concentric striz of growth cross the area and its median ridge or line without interruption;
casts of the interior show the outline of the false area more or less distinctly. The posterior
margin is usually slightly arched beneath the false area.

The dorsal valve is depressed convex, with the greatest elevation in front of the posterior
margin; the beak is minute, marginal, and divided at the center by an elongate depression
that leaves a very minute, slightly elevated, elongate tubercle on each side.

The exterior surface is marked by concentric lines of growth that vary in prominence
and strength, and some ventral valves have a few low, rounded, radiating cost; the cost
differ greatly in length and size, and are entirely absent on many shells. The epidermal layer
is ornamented with a minute granulation formed of very minute granules distributed more
or less irregularly on irregular raised lines distinct from the concentric striz of growth, or
apparently at times superimposed on the latter. The shiny inner layers of the shell are marked
by fine, radiating striz and concentric lines and narrow radiating depressions corresponding
to the external costze. The shell is corneous and built up of thin layers or lamelle that give it
some thickness over the visceral portions; the inner lamellz are slightly oblique to the outer
surface. The average size of the shells at the typical locality at Antelope Springs is from
5 to 6 mm. in length by 6 to 7 mm. in width; a few miles distant and a little higher in the
strata, shells occur 8 to 10 mm. in diameter. Near Montpelier, Idaho, shells from 13 mm. in
diameter to young shells 3 mm. in diameter occur in the same bed of shale.

In the interior of the ventral valve a narrow main vascular sinus arches outward from each
side a little back of the pedicle opening, and then forward into the anterior half of the valve.
The pedicle opening is elongate oval in outline, and has a shghtly elevated rim about it and
on each side a depression corresponding to the elongate tubercles on the exterior of the shell;

62667°—vou 51, pr 1—12—42

658 CAMBRIAN BRACHIOPODA.

the visceral cavity in front of the opening is short, and in some shells very minute pits along
the front indicate muscle scars that are too imperfectly preserved to be identified.

In the posterior half of the interior of the dorsal valve there is a strong median ridge that
bifureates near the center; this ridge enlarges where the central muscle scars (h) occur on its
outer slopes and contracts before bifurcating just in advance of the anterior lateral muscle sca1s
(j) (Pl. LX, fig. 11). The main vascular sinuses originate near the posterior margin at the end
of the median ridge and extend first outward and then obliquely forward as narrow, nearly
straight sinuses that are most deeply impressed in the shell at the inner and outer margins.
The muscle scars have left very faint impressions on the shell. The cardinal scars (cl) are
small and situated at the sharp angle formed by the main vascular sinuses and the posterior
margin of the shell (PI. LX, fig. 1k). The size and position of the central scars (h) and anterior
lateral scars are indicated on Plate LX, figure 11.

I have been able to discover no trace of a true area in either valve; the posterior margins
of the valves show concentric strie and often the under side is striated, the surface apparently
not having been rubbed against the edge of the opposite valve.

Observations.—There are some noticeable variations in this species, one of which I have
separated as the variety Jzvis. In addition there is a variation in the position of the apex
of the ventral valve that is often very marked; part of this variation is explained by the com-
pression and consequent distortion of the shells, but there is also a range in the distance of
the apex from the posterior margin of about one-fifth to one-third the length of the valve.

Acrothele subsidua levis is separated on account of the smoother surface of a large group
of shells occurring in the Middle Cambrian limestone near Ophir, Utah.

The specimens from the Lower Cambrian of Pioche, Nevada, which I [1886b, p. 109]
referred to Acrothele subsidua are now referred to A. spurri, as more perfect specimens show
that although they have the same type of surface the apex of the ventral valve is nearer the
posterior margin and the posterior margin is strongly arched below the false area.

A. subsidua is the Cordilleran representative of the Swedish Acrothele coriacea Linnarsson
and the American Atlantic coast A. matthewi (Hartt). It differs from A. coriacea in its more
finely granulated surface, in the average more anterior position of the apex, in the average
more circular outline of the ventral valve, and in the main vascular sinuses and their branches
in the ventral valve. From A. matthewi it differs in surface characters and interior vascular
markings. A. subsidua is much like Acrothele (Redlichella) granulata (Linnarsson) in form
and size, but it differs in not having the strong granulations of the latter species upon its
outer surface, also in having different interior vascular markings.

The vertical range of this species in the House Range section is from the lower portion
of the Wheeler formation up into the top of the Marjum limestone, a vertical distance of about
1,200 feet. In the shales of the Wheeler formation it is associated with Asaphiscus wheelert
Meek, Ptychoparia kingi (Meek), and Agnostus interstrictus White. In the Marjum limestone
this fauna disappears and a new subfauna of the Middle Cambrian fauna appears in which
Obolus mcconnelli (Walcott) and Micromitra ([phidella) pannula ophirensis (Walcott) occur.
At Ophir, in the Oquirrh Range, Acrothele subsidua levis is abundant at about the same
horizon as the lower portion of the Marjum limestone. On the west front of the Wasatch
Range, in Utah, it is associated with Obolus mcconnella (Walcott) and Acrotreta ophirensis
Walcott.

ForRMATION AND LOCALITY.—Middle Cambrian: (55t) * About 350 feet (106.7 m.) above the Brigham quartzite,
in the limestone of the Ute limestone [Walcott, 1908a, p. 7], on the west side of the road, 0.5 mile (0.8 km.) above
the forks, Paradise Dry Canyon (locally known as East Fork), east of Paradise, Cache County, Utah.

(32p and 55e) Spence shale member of the Ute limestone, about 100 feet (30.5 m.) above the Brigham quartzite
[Walcott, 1908f, p. 197], at the mouth of the first small canyon south of Wasatch Canyon; and (54q) a drift block sup-
posed to have come from about 1,700 feet (518.2 m.) above the Brigham quartzite, a horizon correlated with the shales

forming 2d of the Bloomington formation in Blacksmith Fork Canyon [Walcott, 1908f, p. 195], in Wasatch Canyon;
both east of Lakeview ranch, about 5 miles (8 km.) north of Brigham, Boxelder County, Utah.

a The species is somewhat doubtfully identified from this locality.

ACROTRETID. 659

(15b) About 1,700 feet (518.2 m.) above the Lower Cambrian and 2,700 feet (823 m.) below the Upper Cambrian,
in the shaly limestones and calcareous shales of the Wheeler formation [Walcott, 1908f, p. 181], near Swasey Spring;
(8s and 8g) same horizon as 15b, in the eastern part of Wheeler Amphitheater, east of Antelope Springs; (11u) lower
portion of the shales forming the Wheeler formation in Rainbow Valley; (4) drift pieces believed to have come from the
horizon of 15b, collected near Antelope Springs; (8x) about 2,200 feet (670.6 m.) above the Lower Cambrian and 2,200
feet (670.6 m.) below the Upper Cambrian in the limestones forming 1d of the Marjum limestone [Walcott, 1908f, p.
180], 2.5 miles (4 km.) east of Antelope Springs, in ridge east of Wheeler Amphitheater; (11q, 1ly, and 30g) about
2,350 feet (716.3 m.) above the Lower Cambrian and 2,050 feet (624.8 m.) below the Upper Cambrian, in the limestone
forming 1c of the Marjum limestone [Walcott, 1908f, p. 180], 2.5 miles (4 km.) east of Antelope Springs, in ridge east
of Wheeler Amphitheater; and (10y) about 2,900 feet (884 m.) above the Lower Cambrian and 1,500 feet (457.2 m.)
below the Upper Cambrian in the central part of la of the Marjum limestone [Walcott, 1908f, p. 179], about 1 mile
(1.6 km.) south-southwest of Marjum Pass; all in the House Range [Walcott, 1908f, Pls. XIII and XV], Millard County,
Utah.

(5b and 54s) Dark blue-gray Langston limestone [Walcott, 1908f, p. 198], just above the Cambrian quartzitic
sandstones, north side of Twomile Canyon, near its mouth, 2 miles (3.2 km.) southeast of Malade, Oneida County,
Idaho.

(55e and 163) Spence shale member of the Ute limestone [Walcott, 1908a, p. 8], about 50 feet (15.2 m.) above
the Brigham quartzite and 2,755 feet (839.7 m.) below the Upper Cambrian, in a ravine running’up into Danish Flat
from Mill Canyon; and (59g) limestones immediately overlying the Spence shale member of the Ute limestone [Wal-
cott, 1908a, p. 8], in a saddle north of the creek which flows into Mill Canyon from the west; both about 5 miles (8
km.) west-southwest of Liberty and 15 miles (24.2 km.) west of Montpelier, Bear Lake County, Idaho.

(58j) About 1,900 feet (579 m.) above the Lower Cambrian, and 3,100 feet (945 m.) below the Upper Cambrian
near the base of the limestone forming 2 of the Stephen formation [Walcott, 1908c, p. 238 (7)], on the east side of Mount
Stephen, about 3,000 feet (914 m.) above the Canadian Pacific Railway track east of Field; and (14s) about 2,300 feet
(701 m.) above the Lower Cambrian and 2,700 feet (823 m.) below the Upper Gamaipdem, in the Orwiaansis zone of
the Stephen formation [Walcott, 1908f, p. 210], on the northwest slope of Mount Stephen, above Field on the Cana-
dian Pacific Railway; both in British Columbia, Canada.

ACROTHELE SUBSIDUA HERA Walcott.

cc

Plate LX, figure 9.

Acrothele subsidua hera Waucorr, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, p. 87, Pl. VIII, fig. 15. (Described

and discussed as below as a new species. Fig. 15 is copied in this monograph, Pl. LX, fig. 9.)

This variety is separated from Acrothele subsidua (White) by the more elongate outline
of the ventral valve and more posterior position of the apex, the relative position of the latter
being between the posterior position of the apex of Acrothele spurri and the more anterior
position of the apex of A. subsidua. An obscurely defined false area begins at the apical open-
ing and diverges toward the margin. It is marked by a slight median ridge. The exterior
layers of the shell are exfoliated, carrying with them the outer portion of the apical opening.
The inner portion is rather large, and from the presence of an elongate tubercle on each side
it is apparent that there was a similar tubercle on the interior surface on each side of the apex
a little in advance of the opening.

The surface of an interior layer is marked by fine concentric lines, numerous very fine
radiating lines, and four sharp ridges that radiate from the apex to the front margin.

Observations.—This species is represented by a single specimen that occurs in the buff-
weathering gray limestone interbedded in the shale carrying fragments of Olenellus. It is
quite distinct from A. spurri, with which it is associated, and appears to be a progenitor of
A. subsidua, which occurs so abundantly in the Middle Cambrian strata much higher up in
the section.

FORMATION AND LOCALITY.—Lower Cambrian: (31a) Limestone and interbedded siliceous shales of the Pioche
formation [Walcott, 1908a, p. 11], just above the quartzite on east side of anticline, near Pioche, Lincoln County,

Nevada.
ACROTHELE SUBSIDUA LAVIS Nn. Var,

LL

This variety is distinguished by the partial or complete absence of the fine granulation
on the epidermal layer characteristic of Acrothele subsidua (White). The shells of the variety
have the same general outline and form as the species, and vary in size from 3 to 7 mm. in
diameter.

660 CAMBRIAN BRACHIOPODA.

I do not regard this variety as having much value, as there are numerous gradations from
the smooth surface to the granulated surface typical of the species.

The associated fossils indicate the central portion of the Middle Cambrian section at,
about the horizon of the lower portion of the Marjum limestone of the House Range section
of Utah.

FoRMATION AND LOCALITY.—Middle Cambrian: (3e) Thin-bedded limestone less than 400 feet (121.9 m.) above the
quartzitic sandstones of the Cambrian, at Ophir, Oquirrh Range, Tooele County; and (8x) about 2,200 feet (670.6 m.)
above the Lower Cambrian and 2,200 feet (670.6 m.) below the Upper Cambrian, in the limestones forming 1d of the

Marjum limestone [Walcott, 1908f, p. 180], 2.5 miles (4 km.) east of Antelope Springs, in ridge east of Wheeler Amphi-
theater, House Range [Walcott, 1908f, Pls. XIII and XV], Millard County; both in Utah.

ACROTHELE TURNERI Walcott.

Plate LX, figures 7, 7a.

Acrothele turneri WaucorTt, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, pp. 87-88, Pl. IX, fig. 12. (Described and

discussed as below as a new species. Fig. 12 is copied in this monograph, Pl. LX, fig. 7.)

General outline broad oval, ventral valve slightly conical, with the apex at about the
posterior third of the length of the valve; apex short and perforated on the back side of its
point by a minute pedicle opening; false area indicated by a slight flattening between the
apex and posterior margin. Dorsal valve gently convex; beak marginal.

Surface marked by fine concentric lines and striz of growth. Shell corneous and made
up of a few very thin lamelle.

The largest shell has a length of 2.5 mm.; width, 2.75 mm.

Observations.—This neat little shell differs from Acrothele subsidua (White) in the absence
of the surface characters of that species and from A. spurrt by the more anterior position of
its beak and smooth surface. It belongs to the group of Acrothele represented by A. borgholm-
ensis. (Compare Pl. LX, fig. 7, with Pl. LXIII, fig. 2.)

The specific name was given in honor of Mr. H. W. Turner.

FoRMATION AND LOCALITY.—Middle Cambrian: (7r) Calcareous shales 4 miles (6.4 km.) south-southeast of Emi-
grant Peak, Silver Peak quadrangle (U.S. Geol. Survey), Esmeralda County, Nevada.

Specimens that are somewhat doubtfully referred to Acrothele turnert Walcott occur at the
following locality:

Middle Cambrian: (54a) About 750 feet (228.6 m.) above the Brigham quartzite and 3,440 feet (1,048.5 m.)

below the Upper Cambrian, in the shales forming 2a of the Ute limestone [Walcott, 1908f, p. 196], in Blacksmith Fork
Canyon, about 10 miles (16.1 km.) east of Hyrum, Cache County, Utah.

ACROTHELE VILLABOIMENSIS Delgado.

Acrothele villaboimensis DELGADO, 1904, Communicagdes Commissio Servico Geol. Portugal, tome 5, fasc. 2, p. 365,
Pl. IV, fig. 28. (Described and discussed in French as a new species.)
Obolella maculata DELGADO [not SatTeR], 1904, idem, p. 364, Pl. IV, fig. 24. (Discussed in French.)

Delgado [1904, p. 365] states that this species is characterized by the longitudinally oval -

outline of the ventral valve. The photograph of the type specimen shows that the apex is a
short distance from the posterior margin, and that distinct concentric lines of growth occur,
also that there are three or more fine plications near the front margin. The presence of the
plications appears to indicate that the specimen has been laterally compressed, and thus given
a longitudinally oval outline. If this view is correct the outline of the ventral valve was prob-
ably nearly circular. It may be that Plate IV, figure 24, of ‘‘ Obolella maculata” (Delgado, 1904,
p- 364] represents the dorsal valve of this species.

The only form with which we can compare this species is Acrothele maculata (Salter)
of the Middle Cambrian of Wales. Both species have the apex of the ventral valve far back
toward the posterior margin. Distorted specimens of the ventral valve of Acrothele maculata
have the same outline as the ventral valve of A. villaboimensis. It is not probable that they

ACROTRETIDA. 661

are identical species; they are associated with quite different faunas and little is known of
the specific details of either species.
This species derives its specific name from its occurrence near Villa Boim.

FORMATION AND LOCALITY.—Lower Cambrian: (351 [Delgado, 1904, p. 365]) Shales at Monte de Valbom, north-
east of Villa Boim, Province of Alemtejo, Portugal.

ACROTHELE WooDworRTHI Walcott.

Plate LX, figure 6.

Acrothele woodwortht Watcott, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, p. 88, Pl. IX, fig. 11. (Described and

discussed as below as a new species. Fig. 11 is copied in this monograph, Pl. LX, fig. 6.)

Ventral valve transversely and irregularly oval in outline, convex, with the apex a little
back of the center of the valve; pedicle opening, as indicated by the matrix of the exterior,
just back of the apex; a subtriangular, gently convex false area is obscurely outlined by lines
radiating from the apex to the posterior margin; the posterior margin is arched upward one-
third or more of the distance from the plane of the margin of the valve to the apex.

Surface marked by concentric growth lines with fine strize between, and a number of low,
rounded, more or less obscure, radiating ribs. The shell is relatively thick and replaced by
the calcareous matter of the matrix.

Observations.—This species is based on two specimens of the ventral valve collected by
Prof. J. B. Woodworth. The generic reference is not entirely satisfactory as the pedicle open-
ing has not been clearly seen and the convex false area suggests the area of Micromitra (Pl. II,
fig. 1) more than that of any Acrothele except A. spurri Walcott.

The specific name is given in honor of Prof. J. B. Woodworth.

ForMATION AND LOCALITY.—Lower Cambrian: (326c) “‘Nahant limestone,’’ Pulpit rock, Nahant, Essex County,
Massachusetts.
ACROTHELE YORKENSIS Walcott.
\

\

Plate LIX, figures 4, 4a-b.

Acrothele yorkensis Waucort, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, pp. 88-89, Pl. IX, fig. 10. (Described

and discussed as below as a new species. Fig. 10 is copied in this monograph, Pl. LIX, fig. 4.)

Thisspecies is represented by the casts, in the fine clay shales, of the extericrs of the valves,
and a few imperfect casts of the interior. The shell is large for a species of this genus. Ventral
valve moderately convex, with the apex in a specimen 9 mm. long 1.5 mm. from the posterior
margin. The general outline is subcircular, with the length and width approximately the
same. Dorsal valve with the apex marginal. The original convexity of the valves is unknown,
as all of the specimens are flattened in the shale.

Surface marked by concentric ridges and strie of growth, and a few obscure, rounded,
radiating ridges. In addition there is a fine granulation of the type of that of A. coriacea,
the irregular, more or less inosculating, minute, rounded ridges having fine tubercles upon
them.

A large ventral valve has a length and width of 11 mm. Other specimens of the same
size occur, although the average size is about 8 mm. Substance of the shell is unknown.

One or two poor interiors of the ventral valve show a small visceral cavity, and rather
slender main vascular sinuses that appear to originate beside the pedicle opening. The latter
opens on the back slope of the apex and enlarges as it passes through the shell. The interior
of the dorsal valve shows a rather strong central ridge that extends beyond the center of the
shell, also a rather small cardinal scar on each side of the median ridge close to the posterior
margin.

Observations. —This shell is of the general type of Acrothele matthewi (Hartt). It differs
in its larger size, and it is not probable that a species would occur in the inner Appalachian
trough which is present in the sediments near the margin of the Atlantic Basin. The fauna

662 CAMBRIAN BRACHIOPODA.

associated with <A. yorkensis is of the Middle Cambrian type of the interior trough and
quite unlike that of the Paradowides fauna of the Atlantic Coast Province. In size this species
approaches A. (Redlichella) granulata (Linnarsson), but it differs from that species in its minutely
eranulated surface.

This species derives its specific name from its occurrence near York, Pennsylvania.

ForRMATION AND LOCALITY.—Middle Cambrian: (48d) Argillaceous shales in | railroad cut alongside of gas house,
eity of York, York County, Pennsylvania.

ACROTHELE sp. undt. a.
Plate LXIII, figure 5

This species is represented by a single specimen of a cast of the interior. This cast shows
the base of the apical opening, which is rather large, a short visceral cavity, the central
portion of which was somewhat elevated, and clearly defined main vascular sinuses that originate
at the sides of the base of the pedicle opening, and extend forward well toward the front of the
valve, gradually diverging at the center, so as to be about one-third the distance from the
median ridge to the margin; rather strong muscle scars occur beside the main vascular sinuses,
where the latter curve forward into the body of the valve. Two scars, the transmedian and
anterior lateral, are clearly shown. A fragment of the shell is preserved back of the cast of
the pedicle opening that indicates that the shell was rather thick over the umbonal portions.

The specimen has a length of 7 mm., with the breadth the same. Nothing is known of
the exterior surface. The interior shows a few obscure lines of growth and fine radiating striz.

This species suggests the ventral valve of Acrothele yorkensis Walcott in form, but in the
absence of an exterior or other characters for comparison, no specific designation is given to it.

FORMATION AND LOCALITY.—Lower Cambrian: re) Conglomeratic limestones containing Olenellus?, St. Simon,
Province of Quebec, Canada.

—~ ACROTHELE sp. undt. Moberg.

Acrothele MopErRG, 1892, Geol. Féren. i Stockholm Férhandl. for 1902, Bd. 14, Hit. 2, pp. 114-115, Pl. III, fig. 9.
(Described in Swedish; see below for translation.)

Moberg describes the species as follows:

Of this genus, none but exfoliated specimens have been met with. They do not appear to show characters sufficient
for specific determination. The shell hasan almost circular circumference, with the back edge, along a distance
constituting about one-fifth of the whole circumference, somewhat truncated. From the apex, which is situated
near the posterior margin, the shell slopes pretty evenly both toward the anterior and the posterior margins, so that
these two parts form approximately a right angle with each other at the apex. ‘Traces of concentric lines of growth
are visible.

In the position of the apex and the convexity of the ventral valve the cast of this shell
is much like that of the forms from the Lower Cambrian of Bic, Canada (Pl. LXIII, fig. 5).
ForRMATION AND LOCALITY.—Lower Cambrian: (310e) Sandstone bowlder on the beach between Ekerum and Stora

Rr; (310£) sandstone bowlders west of Ekerum; and (310g) sandstone bowlders south of Stora Ror; all [Moberg, 1892b,
p. 115] on Oeland Island, Sweden.

REDLICHELLA Walcott,* subgenus of ACROTHELE.

Acrothele (Redlichella) Waucort, 1908, Smithsonian Misc. Coll., vol. 58, No. 3, pp. 89-90. (Described and discussed
as below as a new subgenus.)

Acrothele (Redlichella) Waxcort, 1908, idem, vol. 53, No. 4, pp. 142 and 146, and Pl. XI. (Classification of subgenus.)
This subgenus of Acrothele has all the external characters of the type species of Acrothele,

A. coriacea Linnarsson. It differs in the interior markings of the valves. The visceral area

a The synonymy for this subgenus does not give acomplete record of the various genera under which the species now included in Iedlichella
were formerly placed. It gives only those references in which the genus is discussed or described. To complete the record the following mere
generic references are listed:

Acrothele Linnarsson [1876, p. 24]. Acrothele Walcott [1886b, p. 109].
Acrothele Swanston [1877, Pl. VII, figs. 20a-c]. Acrothele Swanston [1886, Pl. VII, figs. 20a-c].
Acrothele Linnarsson [1877, p. 373]. Acrothele Hall and Clarke [1892c, p. 100].

Acrothele Davidson [1883, p. 214].

ACROTRETIDL. 663

of the ventral valve is large and clearly defined, as in Botsfordia granulata (Redlich), and the
main vascular sinuses are very strong and close to the pedicle aperture, as in the latter species.
In the interior of the dorsal valve the cardinal scars are very large and extend forward nearly
one-third the length of the valve.

Type.—Acrothele granulata Linnarsson.

J was at first inclined to place this form under Botsfordia, but the advanced position of the
apex and pedicle opening of the ventral valve indicates a closer affiliation with Acrothele. The
short listrium of Botsfordia has developed in Redlichella to the strong false area of Acrothele,
but the visceral area and main vascular sinuses of Botsfordia remain practically unchanged.
IT regard Redlichella as a form intermediate in development between Botsfordia and Acrothele.

The subgeneric name is given for Dr. Karl A. Redlich, of the Geological Survey of India.

ACROTHELE (REDLICHELLA) GRANULATA (Linnarsson).
v Plate LVI, figures 2, 2a—n.

Acrothele granulata LinNarsson, 1876, Bihang till K. svensk. Vet.-Akad. Handl., Bd. 3, No. 12, p. 24, Pl. IV, figs.
5la-c (and 52?). (Described and discussed in English as a new species.)

Acrothele sp., A. granulata Linnarsson, SwANSTOoN, 1877, Proc. Belfast Naturalists’ Field Club, Appendix 4, for 1876-77,
Pl. VII, figs. 20a-c. (No text reference.)

Acrothele granulata Linnarsson, 1877, Geol. Féren. i Stockholm Férhandl., No. 40, Bd. 3, No. 12, pp. 373-374, Pl.
XV, figs. 12, 12a-b. (Described in Swedish.)

Acrothele granulata Linnarsson, Davipson, 1883, British Fossil Brachiopoda, vol. 5, pt. 2, p. 214, Pl. XVI, figs. 29,
29a, 30, 30a-b. (Original description copied and species discussed.)

Acrothele granulata Linnarsson, Watcort, 1886, Bull. U. 8. Geol. Survey No. 30, p. 109. (Mentioned as closely related
to Acrothele subsidua.)

Acrothele sp., A. granulata Linnarsson, Swanston, 1886, Systematic Lists, Flora, Fauna, Paleontology, and Arche-
ology, North of Ireland, vol. 1, Pl. VII, figs. 20a-c. (Reprint of Swanston, 1877, Pl. VII, figs. 20a-c.)

Acrothele granulata Linnarsson, Haut and CuarxKeE, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, pp. 100-
101. (Discussed.)

The shell of Acrothele (Redlichella) granulata resembles so closely that of Acrothele coriacea
Linnarsson (p. 642) that I will only call attention to the points of difference between them.

On the average, A. (2.) granulata is a longer, stronger shell; its surface is more coarsely
granular, the pedicle aperture is much larger, and the tubercles in front of it much smaller.
The false area is usually less distinct, but it is sometimes distinct and has a longitudinal median
line; the posterior margin arches up at the false area, and the dorsal valve arches up so as to
fit closely against the curved margin; the interior of the ventral valve of A. (f.) granulata
has a visceral area that is obtusely pointed in front and on each side extends out to the main
vascular sinuses, which originate nearer the pedicle opening than in A. coriacea. The main
vascular sinuses of A. (&.) granulata are much nearer the median line than those of A. coriacea.
The difference in the visceral area and vascular sinuses was found in specimens from the Para-
doxides forchhammeri beds of Gudhem, and also the P. elandicus zone of Bornholm.

In the dorsal valve of A. (R.) granulata the cardinal scars are longer and nearer the median
ridge.

A large ventral valve has a length of 9 mm.; width, 10.5 mm. A large dorsal valve has
a length of 10 mm.; width, 12 mm.

Acrothele (Redlichella) granulata is a form intermediate between the typical <Acrothele
coriacea Linnarsson and Botsfordia granulata (Redlich). It has the exterior appearance of
Acrothele coriacea, and the apex of the ventral valve is well in advance of the posterior margin,
but the interior of the ventral valve has the strongly marked visceral area of Botsfordia gran-
ulata, and strong vascular sinuses that are close to the pedicle opening.

ForMATION AND LOCALITY.—Middle Cambrian: (8z) Limestones of Paradoxides elandicus zone at Borgholm,
Oeland Island; (309f) shale at Borgholm, Oeland Island; (3100) limestone of the Paradosides tessini zone at Borgholm,
Oeland Island; (320s [Linnarsson, 1877, p. 374]) at St. Fré, Oeland Island; (320b) limestones forming 2d of the Para-
doxides zone, the Agnostus levigatus horizon, at Gudhem, 12.5 miles (20.1 km.) south-southeast of Skara, Province
of Skaraborg; (3201 [Linnarsson, 1876, p. 24]) drift blocks supposed to have come from the Paradoxides elandicus zone

[Linnarsson, 1876, p. 6], at Lillviken, near Oestersund, Province of Jemtland; and (320t [Linnarsson, 1876, p. 24]) on
Billstaan River, parish of Hackas, Province of Jemtland; all in Sweden.

664. CAMBRIAN BRACHIOPODA.

Genus DISCINOLEPIS Waagen.
[décxoc, quoit; and Jezéc, scale.)

Discinolepis WAAGEN, 1885, Mem. Geol. Survey India, Paleontologia Indica, 13th ser., Salt Range Fossils, vol. 1,
pt. 4, fas. 5, pp. 749-750. (Described and discussed as a new genus, part of the next to the last paragraph being
copied below.)

Discinolepis Waagen, Hatt and CrarKn, 1892, Eleventh Ann. Rept. State Geologist New York for 1891, p. 247.
(Described.)

Discinolepis Waagen, Hatt and CrarKe, 1892, Forty-fifth Ann. Rept. New York State Museum for 1891, p. 563. (Copy
of preceding reference.)

Discinolepis Waagen, Hatt and CuarKe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, p. 90. (Original
description, Waagen, 1885, p. 749, copied.)

Discinolepis Waagen, Waucorr, 1908, Smithsonian Misc. Coll., vol. 53, No. 4, Pl. XI, and pp. 142 and 146. (Classi-
fication of genus.)

As this genus is based on one species, the description of the latter will give all that is
known of the genus. Waagen [1885, p. 749] states that this genus differs from all described
genera of the Discinide:

From Discina, Discinisca, and Orbiculoides it differs in having an incision and not a slitlike foramen in its lower
valve for the passage of a peduncle. In Trematis a similar incision or emargination seems sometimes to occur, but

the sculpture of the valves is quite different from that appearing in Discinolepis. Schizocrania has an incision, but
it is much larger than in the Indian form.

Type.—Discinolepis granulata Waagen.

DIscINOLEPIS GRANULATA Waagen.

Plate LX XX1I, figures 3, 3a—b.

Discinolepis granulata WAAGEN, 1885, Mem. Geol. Survey India, Paleontologia Indica, 13th ser., Salt Range Fossils,
vol. 1, pt. 4, fas. 5, pp. 750-751, Pl. LX X XVI, figs. 5, 6, and 7. (Described and discussed as a new species.
The specimen represented by fig. 6 is redrawn in this monograph, Pl. LX XX1, fig. 3; the specimen represented
by fig. 5 is redrawn (in different positions) in this monograph, Pl. LX XX1I, figs. 3a and 3b.)

Discinolepis granulata WAAGEN, 1891, idem, vol. 4, pt. 2, Pl. II, figs. 15 and 16. (No text reference. Figs. 15 and 16
are drawn from the specimens represented in the preceding reference, Pl. LX X XVI, figs. 5 and 6, respectively.)

Discinolepis granulata Waagen, Haut and CrarKe, 1892, Eleventh Ann. Rept. State Geologist New York for 1891,
p. 247, figs. 256 and 257. (No text reference. Figs. 256 and 257 are copied from Waagen, 1885, Pl. LXX XVI,
figs. 5b and 7, respectively.)

Discinolepis granulata Waagen, Hatt and CLARKE, 1892, Forty-fifth Ann. Rept. New York State Museum for 1891,
p. 563, figs. 256 and 257. (Copy of preceding aeltmvemee. )

Discinolepis granulata Waagen, Hatt and CrarKe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, p. 90, figs.
45 and 46. (No text reference. Figs. 45 and 46 are copied from Waagen, 1885, Pl. LX: X XVI, figs. 5b and 7,

respectively.)

Shell transversely broad oval. Ventral valve nearly flat except at the umbo and apex.
Apex a little in front of the posterior margin and about three-fourths of a millimeter high; it
is divided by a median depressed line which gives a slightly elevated semicircular node on each
side. From the depressed median line a narrow, elongate, triangular opening extends to the
margin of the valve; this opening has the position and form of the false deltidium of some
species of Acrotreta, but there is no outline of an area. The lines and striz of ease arch
around and terminate at the edges of the opening.

Surface of the shell marked by fine concentric lines of erowth and fine papillze which are out-
lined by oblique lines curving from each side of the shell forward and then outward to the
opposite side from which they originate. It is the same type of surface as that on Micromitra
(Iphidella) pannula (White) (PI. ITV). Where the surface is slightly worn the papillz appear like
fine granules.

The substance of the shell appears to be caleareocorneous and the shell to be made up of
several thin lamelle. The two ventral valves are 5 mm. in width and 4 and 5 mm. in length,
respectively.

These measurements differ from Waagen’s, but as the shells are imperfectly preserved at
margins the size assumed is a matter of personal judgment.

ACROTRETIDA. . 665

Waagen [1885, p. 750] describes the dorsal valve from specimens on a slab of sandy shale
that are more or less crushed. The surface of these shells is marked only by very fine concentric
strize and two show an opening beneath the apex similar to that of the ventral valve of Dis-
cinolepis granulata. I do not find in the material any clearly defined dorsal valve with the papil-
lose surface. The material representing the concentrically striated species is too poorly pre-
served to warrant the description of a second species. I do not know of any related species.

I am indebted to the director of the Geological Survey of India, Dr. T. H. Holland, for the
opportunity to study and illustrate the type material of this genus and species.

FORMATION AND LOCALITY.—Middle Cambrian: Lower portion of the ‘‘ Neobolus beds” of the Khussak group, in
purplish-colored, fine-grained, micaceous sandstone at the following localities [Waagen, 1885, p. 751]; (857%a) at Jutdna;
and (857c) near the fresh-water springs in the gorge above the salt mines at Kiura (Khewra); both in the Salt Range,
India.

Subfamily ACROTRETIN4® Walcott and Schuchert.
Genus LINNARSSONELLA Walcott.

LInnnarssonella Waxucotr, 1902, Proc. U. S. Nat. Mus., vol. 25, pp. 601-602. (Described and discussed as below as a
new genus.)

Linnarssonella Waxcorr, 1908, Smithsonian Mise. Coll., vol. 53, No. 4, Pl. XI, and pp. 142 and 146. (Classification of
genus.)

Ventral valve convex with a slightly incurved beak projecting over a low false area.
Pedicle opening at the apex of the beak. A very slight trace of a pseudodeltidium occurs
beneath the beak, dividing the false area midway, as in the genus Micromitra; the false area
arches slightly upward and backward in some specimens, while in others of the same species
its edge is nearly coincident with the plane of the edge of the shell. The true cardinal area is
well defined and strongly marked by a shallow pedicle furrow (Pl. LX XVIII, figs. 8e and 9b).
The dorsal valve is slightly convex, with a minute beak at the posterior margin. Surface
marked by very fine concentric striz and undulations of growth. Shell strong, thick, and
built up of a thin outer layer and numerous inner layers or lamelle that are arranged more or
less obliquely to the outer layer. All the known species are small, not exceeding 2.5 mm. in
diameter.

The cast of the interior of the ventral valve shows the presence of two well-marked car-
dinal scars, one on each side of the main vascular canals well toward the posterior border of
the valves. The main vascular canals of the ventral valve were large, extending nearly to the
frontal margin, and including between them back of the center of the valve a small visceral
area. ‘The cast of the pedicle opening occurs just in front of the union of the main vascular
sinuses. The cast of the interior of the dorsal valve (Pl. LX XIX, fig. 11) shows two large
cardinal scars; two central scars (h); and traces of a minute anterolateral scar (j); strong
vascular canals; a well-defined area and pedicle furrow; and a narrow median ridge extending
in some shells to the anterior third of the valve.

Type.—Linnarssonella girtyi Walcott; second species, L. minuta (Hall and Whitfield);
third species, L. tennesseensis Walcott.

This is a most interesting type, combining characters of Micromitra and Acrotreta. Bicia,
of the Olenellus fauna, has a strikingly similar dorsal valve, and the ventral valve is not unlike
if the narrow pedicle furrow of Bicia is closed so as to provide a pedicle aperture.

Linnarssonella girtyz occurs in great abundance in a single layer in the Middle Cambrian
of the Black Hills, North Dakota; also at two localities at the same relative stratigraphic
horizon in Oklahoma and at several localities in the Middle Cambrian limestones of Missouri.

@ The synonymy for this genus does not give a complete record of the various genera under which the species now included in Linnarssonella
wereformerly placed; it gives only those references in which the genus is discussed or described. To complete the record the following mere generic
references are listed:

Lingulepis? Hall and Whitfield [1877, p. 206]. Oboleila Walcott [1899, p. 443).
Lingulepis ? Walcott [1884b, p. 13). Acrotreta Walcott [1901, p. 673).
Obolella? Walcott [1897a, p. 404]. Meekina Walcott [1905a, p. 313).

Linguleila Schuchert [1897, p. 257).

666 CAMBRIAN BRACHIOPODA.

The Missouri specimens were at first thought to be a distinct species, to which the name
L. broadheadi was given, but the description was not published. By oversight the name
L. broadheadi was published [Walcott, 1902, p. 601] in the preliminary notes on the genus.
The valves of LZ. minuta almost cover a fragment of sandy shale from the Kureka district,
Nevada. Linnarssonella tennesseensis is fairly abundant in sandy shales and thin-bedded sand-
stones, also in argillaceous shales above the sandstone of the Rome formation. Three
species occur in the Upper Cambrian of the House Range section of western Utah. The lowest
in the section is L. transversa; about 200 feet higher in the section, L. modesta; and a short
distance above, L.- nitens. These species occur in abundance in the bluish-gray limestones.
Linnarssonella wrania is moderately abundant m the Middle Cambrian, compact, dove-colored
limestones of the Wasatch Range.

Failing to establish a satisfactory genus in honor of Linnarsson in the first instance,? I
make another attempt with this rare and interesting form.

es LINNARSSONELLA GirRTYI Walcott.

Plate LX XVIII, figures 5, 5a; Plate LX XIX, figures 1, la—.

Linnarssonella broadheadi Watcorr, 1902, Proc. U. S. Nat. Mus., vol. 25, p. 601. (Name referred to but not defined
or described.)
Linnarssonella girtyi Waucott, 1902, idem, pp. 602-603. (Described and discussed as below as a new species.)

Shell minute. General form broad ovate to subcircular. Ventral valve convex; beak
small and slightly mcurved over the false area; false area short and varying from vertical to
a backward inclination of 45° to 50° with the plane of the edge of the valve; im some examples
the margin of the false area arches (Pl. LX XIX, fig. 1a’) but im others it appears to be straight
(fig. 1b). A very slightly indicated pseudodeltidium occurs beneath the beak that gradually
widens to the margin, very much as in Micromitra pealer. Pedicle openmg minute exteriorly,
but the tube increases in size toward the inner surface of the shell. In one very perfect shell
the aperture appears to open into a narrow elongate depression just in front of the beak, but
it usually is seen as a minute, circular perforation at the apex of the beak. Dorsal valve
gently convex, with a minute beak at the posterior margin. Surface of the shell glossy and
smooth to the unaided eye, but a strong magnifier shows very fine concentric strize and lines
of growth; the inner surface is marked outside of the visceral area by very fine radiating strie.
The shell is formed of several layers or lamelle, and, judging from the depth of the impressions
of the muscle scars and vascular markings, rather thick over the central and posterior por-
tions. The average length of the ventral valve is 1.5 to 1.75 mm.; the dorsal valve is slightly
shorter.

The cast of the interior of the ventral valve shows the presence of a large cardinal scar
on each side of the visceral area, and outside of the very strong vascular canal; they are oval
in outline and probably the point of attachment of a strong muscle or muscles; their variation
in size and position is shown by Plate LX XIX, figures 1k and 1m—p. The visceral area is
small, but is well defined in Plate LXXIX, figures 1n, lo, and 1p. Of the vascular canals only the
main trunks are shown by strong ridges in the casts, their form and extension being finely exhibited
by figures 1m to 1p; in figure 1k they extend almost in a direct line from the beak to the
anterolateral margins of the valve. The cast of the interior of the pedicle tube is usually
broken off; its position is shown in Plate LX XIX, figure In. The interior of the dorsal valve
is beautifully shown by figure 11; thestrong cardinal area with its well-defined pseudodeltidium,
the large oval cardinal scars immediately in front of the area, and the strong vascular canals
are as clearly defined as in the large shells of Obolus. The cardinal scars are divided into three
parts by two transverse lines crossing the outer slope more or less obliquely, but the divisions
on the two sides are unequal; the inner slopes of the scars are finely polished and afford no
evidence of the attachment of muscles. Traces of the central scars occur on the outer slope

a Linnarssonia [Walcott, 1885, p. 115], now referred to A crotreta.
b Under the impression that the forms were distinct this name was given to them, and the name was overlooked when the description of the
genus was published [Walcott, 1902, p. 601).

ACROTRETIDA. 667

of the cast of a rather strong median ridge; they are elongate oval in outline, the major axis
inclining posteriorly toward the median ridge. What may be the impression of an antero-
lateral sear occurs on the median ridge a little in advance of the central scars.

Observations.—Linnarssonella girtyt differs from L. minuta (Hall and Whitfield) in the
greater convexity of the ventral valve and the median ridge of the dorsal valve. The Oklahoma
specimens show a longer false area (Pl. LX XIX, fig. 1q’’) on some shells but on others it is
much like that of L. girtyi from the Black Hills.

The specific name is given in recognition of the paleontologic work of Dr. George H. Girty.

FORMATION AND LOCALITY.—Upper Cambrian: (369) Sandstone in the Elvins formation in the eastern limits of the
town of Flat River, St. Francois County, Missouri.

(9q) About 10 feet (3 m.) above the porphyry contact and 90 feet (27.4 m.) below the Arbuckle limestone, in
limestone of the Reagan sandstone, in middle of W. 4 sec. 2, T. 4 N., R. 13 W.; (9r) about 45 feet (14 m.) above the
porphyry contact in the limestone of the Reagan sandstone, in SE. NE. }sec. 2, T. 4 N., R. 13 W.; and (9p) about
160 feet (48.8 m.) above the porphyry contact in the limestone of the Reagan sandstone, in SE. } NE. } sec. 2, T. 4
N., R. 13 W.; all about 15 miles (24.2 km.) northwest of Fort Sill, Comanche County, Oklahoma.

(9v) Limestone of the Reagan sandstone, about 250 feet (76 m.) below the Arbuckle limestone, SW. } sec. 17, T.
4N., R. 12 W., about 11 miles (17.7 km.) northwest of Fort Sill, Comanche County, Oklahoma.

(12p) About 225 feet (69 m.) above the igneous rocks in the limestone of the Reagan sandstone at the northwest
extremity of the Arbuckle Mountains, about 4 miles (6.4 km.) east of Homer, Carter County, Oklahoma.

(14i) Limestone 1 mile (1.6 km.) west of Cherokee, San Saba County, Texas.

(32t) Limestone about 3,650 feet (1,112.5 m.) above the Cambrian quartzitic sandstones, in Fandango Spring
canyon on the east side of the Dugway Range, about 5 miles (8 km.) north of where the stage road between Vernon
and Deep Creek crosses the divide, Tooele County, Utah.

Middle Cambrian: (88a) Limestone about 100 feet (30.5 m.) above the quartzitic sandstone at the base of the Cambrian,
im the northern suburbs of Deadwood; (165) limestone on the east side of the valley in railroad cut about 1 mile (1.6
km.) below the main part of Deadwood; and (17k) limestone thrown out on the dump of the Great Northern shaft,
southeast of Twobit; all in the Black Hills, South Dakota.

(11k) Limestones of the ‘“‘Edgewise beds,’’ beneath the Elvins formation, St. Francois County; and (11e) thin-
bedded limestone south-southwest of Potosi, Washington County; both in Missouri.

(318e) Limestone 2 miles (3.2 km.) west of Green’s ranch, White Pine County, Nevada.

A shell that is somewhat doubtfully referred to this species occurs at the following locality:

Upper Cambrian: (9q) About 10 feet (3 m.) above the porphyry contact and 90 feet (27.4 m.) below the Arbuckle
limestone, in limestone of the Reagan sandstone, in middle of W. } sec. 2, T.4N., R. 13 W., about 15 miles (24.2
km.) northwest of Fort Sill, Comanche County, Oklahoma.

LINNARSSONELLA MINUTA (Hall and Whitfield).

Plate LX XIX, figures 2, 2a-b.

Lingulepis? minuta Haut and WurrrietD, 1877, U. 8S. Geol. Expl. 40th Par., vol. 4, pt. 2, pp. 206-207, Pl. I, figs. 3
and 4. (Described and discussed as a new species. The specimens represented by Pl. LX XIX, figs. 2, 2a-b,
occur on the same hand specimen of sandy shale as the specimens figured by Hall and Whitfield, but they are
not the same specimens.)

Lingulepis? minuta Hall and Whitfield, Watcorr (in part), 1884, Mon. U. 8. Geol. Survey, vol. 8, p. 138. (Localities
and range mentioned, see p. 668.) ~

Obolella? minuta (Hall and Whitfield), Waxcorr, 1897, Am. Jour. Sci., 4th ser., vol. 3, p. 404. (Merely changes
generic reference.)

Lingulella minuta (Hall and Whitfield), ScaucnErT, 1897, Bull. U. 8. Geol. Survey No. 87, p. 257. (Merely changes
generic reference.) ;

Obolella minuta (Hall and Whitfield), Waxcorr, 1899, Mon. U.S. Geol. Survey, vol. 32, pt. 2, p. 443. (Merely changes
generic reference.)

Acrotreta minuta (Hall and Whitfield), Waucorr, 1901, Proc. U.S. Nat. Mus., vol. 23, p. 673. (Merely changes generic
reference.)

FEinnarssonella minuta (Hall and Whitfield), Watcorr, 1902, idem, vol. 25, pp. 603-604. (Described and discussed
as below.) '

Shell small; general form broad ovate, with the ventral valve slightly subacuminate.
The convexity of the two valves is nearly the same and in each the minute beak appears to
be at the posterior margin. The false area of the ventral valve is small and divided midway
by a faint, narrow pseudodeltidium; it is on the plane of the margin of the valve. Pedicle

668 CAMBRIAN BRACHIOPODA.

opening minute, elongate, and situated on the slope just in front of the beak. Dorsal valve
a trifle less convex than the ventral.

The outer surface of the shell is marked by fine concentric striz and lines of growth, and
the inner lamellz and imner surface are marked by fine radiating strie. The shell is formed
of several thin layers or lamellz, those of the anterior and lateral portions being more or less
cblique to the outer surface layer; the shell is also thickened in the visceral region by irregular
additions on the inside. The average length of the ventral valve is 2 to 2.5 mm.; the dorsal is
a little shorter. The interior of the ventral valve shows a cardinal scar on each side well out
toward the lateral margin, which corresponds to the position of the transmedian and antero-
lateral scars in Obolus apollinis. The visceral area is small and compressed between the sinuses
occupied by the large, main vascular canals. The inner opening of the pedicle tube is oval
and situated at the posterior portion of the visceral depression at the margin of the area. The
main vascular canals start near the beak and gradually diverge toward the anterolateral
margins of the valve. The interiors of the dorsal valve associated with the two ventral valves
illustrated are all so imperfect that only a median ridge like that in Acrotreta can be clearly
determined; this ridge varies greatly in size and length in different specimens.

Observations.—In a hasty examination of this species [1884b, p. 13] I confused the dorsal
valve with that of Acrotreta and considered the ventral valve as the type, placing it under
Lingulepis, stating that it had nearly the same vertical range and geographic distribution as
Obolus mera. As now known it is confined to the following localities, one of the two being the
locality discovered by the geologists of the Fortieth Parallel Survey.

The generic reference is somewhat doubtful on account of our limited knowledge of the
interior of the dorsal valve and the position of the area of the ventral valve.

ForMATION AND LOCALITY.—Ordovician: (318k) Limestone in the White Pine district, Nye County, Nevada.
Upper Cambrian: (318h) Sandy shale on Hamburg Ridge, Eureka district [Hague, 1892, Atlas], Eureka County,
Nevada.

LINNARSSONELLA MODESTA Walcott.

Plate LXX VIII, figures 8, 8a-f.

Linnarssonella modesta Watcort, 1908, Smithsonian Misc. Coll., vol. 538, No. 3, pp. 90-91, Pl. IX, figs. 8 and 8a. (De-
scribed and discussed as below as a new species. Jigs. 8 and 8a are copied in this monograph, Pl. LX XVIII,
figs. 8 and 8e, respectively.)

Shell minute; general form subcircular. Ventral valve moderately convex; beak small
and slightly incurved over a very low false area; pedicle opening minute exteriorly, with a
slightly elevated, sharp ridge on each side a little in advance of the point of the beak; seen
from the back, the minute aperture points backward from the bottom of a pit between the
two short, sharp ridges; in a specimen from a layer of limestone a short distance above in
the section, the aperture is at the point of a small nipple-like projection, apparently formed
by the union of the ends of the ridges already described on each side of the aperture. Dorsal
valve slightly convex, with a minute beak at the posterior margin.

Surface dull when the outer layer of the shell is preserved; it is marked by a few very
fine, concentric lines of growth. The imner surface is marked by concentric lines and a few
fine radiating lines. The shell is formed of several layers or lamellz and is relatively thin.

The average diameter of the adult shell is from 1.75 to 2.25 mm.; the dorsal valve slightly
shorter than the ventral.

The cast of the interior of the ventral valve shows a slight, longitudinal, median elevation
and two short, not very strongly marked main vascular sinuses; several specimens indicate
a slight cavity just beneath the aperture, which probably represents the inner side of, the
pedicle tube. The interior of a dorsal valve shows main vascular sinuses quite close to the
outer margin; also two small, rounded median depressions a short distance in front of the
posterior margin.

Observations —This shell occurs in great abundance on the surface of shaly, gray lime-
stone, about midway of the strata referred to the Upper Cambrian in the House Range

eee

ACROTRETIDZ. 669

section. It differs from L. nitens, which occurs a short distance above it in the section, and
with which it is also associated, in having a less elevated ventral valve and a less convex dorsal
valve; and from L. transversa in being more rounded in outline and less convex. It appears
to be more nearly related in form to L. minuta (Hall and Whitfield); it differs, however,
materially in the character of the interior markings of the ventral valve, features which also
separate it from L. girtyi Walcott and L. tennesseensis Walcott.

FoRMATION AND LOCALITY.—Upper Cambrian: (30k) 1,150 feet (350.5 m.) above the Middle Cambrian and 2,175
feet (662.9 m.) below the top of the Upper Cambrian, at the top of the arenaceous shales and limestones forming te of the
Orr formation [ Walcott, 1908f, p. 176]; and (31t) about 1,175 feet (358.1 m.) above the Middle Cambrian and 2,150
feet (655.3 m.) below the top of the Upper Cambrian, in the limestone forming 1d of the Orr formation [Walcott, 1908f,

p. 176]; both on Orr Ridge, about 5 miles (8 km.) south of Marjum Pass, House Range [Walcott, 1908f, Pl. XIII],
Millard County, Utah.

LINNARSSONELLA NITENS Walcott.

Plate LX XVIII, figures 7, 7a.

Linnarssonella nitens Watcott, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, p. 91, Pl. IX, fic. 7. (Discussed as
below as a new species. Fig. 7 is copied in this monograph, Pl. LX XVIII, fig. 7.)

The outline of the valves and the exterior appearance of this shell are much like those of
L. modesta. It differs in having on the ventral valve a low, distinct area, with the perforated
apex directed backward on nearly the same plane as the umbo, or most elevated portion of
the valve. The dorsal valve is more convex and its interior has a strong median ridge extend-
ing forward from the posterior margin about two-thirds of the distance to the front margin,
a feature but little developed in L. modesta. From L. minuta (Mall and Whitfield) it differs
in the higher apex of the ventral valve, and from L. transversa in the latter character and in
the more circular outline of the aperture of the valves.

A single specimen of L. modesta was found associated with this species.

In size L. nitens varies from 1.5 to 2 mm. in diameter.

FORMATION AND LocALITy.—Upper Cambrian: (31t) About 1,175 feet (858.1 m.) above the Middle Cambrian and
2,150 feet (655.3 m.) below the top of the Upper Cambrian, in the limestone forming 1d of the Orr formation [ Walcott, 1908f,
p. 176], on Orr Ridge, about 5 miles (8 km.) south of Marjum Pass, House Range [ Walcott, 1908f, Pl. XIII}, Millard
County; and (32g) about 2,575 feet (784.9 m.) above the Cambrian quartzitic sandstones, in a blue limestone about

2 miles (3.2 km.) southeast of Muskrat Spring, on the northwest face of Grantsville Peak, Stansbury Range, Tooele
County; both in Utah.

LINNARSSONELLA TENNESSEENSIS Walcott.
Va Plate LXXIX, figures 3, 3a-k.

Linnarssonella tennesseensis Watcotr, 1902, Proc. U. S. Nat. Mus., vol. 25, pp. 604-605. (Described and discussed
as below as a new species.)
Meekina prima Watcort, 1905, idem, vol. 28, p. 313. (Name referred to, but it was not defined or used elsewhere. 2)

General form of yentral valve rounded subtriangular, moderately convex, with the beak
curving gently over a very low false area nearly to the posterior margin. Pedicle opening
minute and situated a little in front of the beak.

Surface of shell marked by fine concentric striz and lines of growth. The interior surface
shows a few fine, radiating striz. Shell rather thick and built up of several thin layers or
lamellze.

The cast of the interior of the ventral valve shows small cardinal scars and a minute pedicle
tube directed backward, very much as in Obolella atlantica Walcott (Pl. LV, figs. 1f-h). The
area is short, narrow, and divided by a deep, narrow pedicle furrow; on each side of the latter
the area projects into the valve so as to form a shelf, with a thickening at the interior angle
next to the pedicle furrow; the central visceral area is confined mainly to the deep median
groove; an elevated area about the anterior end of the groove probably served as the point
of attachment of the central muscle; the main vascular sinuses are very strong and project
well toward the front part of- the valve; the composite cardinal muscle scars, which served

aA shell is referred to as Meekina prima, but before the generic or specific description was published I found that the specimens were casts
of the interior of Linnarssonella tennesseensis.

670 CAMBRIAN BRACHIOPODA.

as the point of attachment of the transmedian and anterior laterals, are situated close to the
posterior lateral margin of the valve.

The dorsal valve has a very short and narrow area, with a small but distinct slightly con-
cave shelf-like projection in front of it; on each side near the posterior lateral margins a strongly
defined cardinal posterior muscle scar occurs that served as the point of attachment of the
transmedian, outside lateral, and middle lateral muscles. The central scars are a little in
advance of the center of the valve. None of the specimens show the main vascular canals
except at their base. The shells average about 3 mm. in diameter.

Observations.—The material representing this species occurs as casts of the interior and
exterior surfaces, in a fine argillaceous shale. It is owing to the removal of the shell substance
by solution that the cast of the area and area-like shelf of the dorsal valve is so clearly shown,
also the posterior muscle scars, visceral area, etc., of the ventral valve.

The shell has the general outline of Linnarssonella girtyz Walcott; but it differs in having
the ventral valve more acuminate, less convex, and in the apex curving over nearly to the
posterior margin. It has the outline of L. minuta (Hall and Whitfield), but not the strong
vascular sinuses and small cardinal sears of the ventral valve of that species.

The perforate ventral valve and large cardinal muscle scars relate this species to Linnars-
sonella. The composite cardinal muscle scars, area, and projection of the inner angles of the
area into the area of the ventral valve, and also the interior of the dorsal valve, suggest Dicel-
lomus. The spondylium-lke shelf of the dorsal valve, indicated in the cast, may be only the
cast of the area projecting out into the valve (Pl. LX XIX, fig. 1r, of Linnarssonella girtyi).
The cardinal scars and shelf-like areas of the valve separate this species from Obolella.

FORMATION AND LOCALITY.—Upper Cambrian: (31t) About 1,175 feet (358.1 m.) above the Middle Cambrian and
2,150 feet (655.3 m.) below the top of the Upper Cambrian, in the limestone forming 1d of the Orr formation [ Walcott,
1908f, p. 176], on Orr Ridge, about 5 miles (8 km.) south of Marjum Pass, House Range [Walcott, 1908f, Pl. XIII],
Millard County, Utah. ‘

Middle Cambrian: (13) Sandstones of the Rome formation, 1.5 miles (2.4 km.) east of Post Oak Springs | Hayes,
1894, areal geology sheet], Roane County; (107b) shales in railroad cut in Bull Run, northwest of Copper Ridge [Keith,
1896b, areal geology sheet], 11 miles (17.6 km.) northwest of Knoxville, Knox County; and (12) sandy shale on Webbs
Ridge in gap west of Simpson’s farm, 6 miles (9.6 km.) northeast of Knoxville, Knox County; allin Tennessee.

LINNARSSONELLA TRANSVERSA Walcott.
Plate LX XVIII, figures 6, 6a-c.
Linnarssonella transversa WAucott, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, p. 92, Pl. IX, fig. 6. (Discussed as

below as a new species. Fig. 6 is copied in this monograph, Pl. LX XVIII, fig. 6.)

This is a small shell that at first sight suggests L. modesta; it differs from that species in
the valves being more convex, transverse instead of circular, and in having stronger concentric
strie, and, in some instances, radiating strie. A few fragments of the interior of the dorsal
valve indicate that the main vascular sinuses are well out toward the outer margin, and that
small circular depressions occur on each side of the median line, very much as in the dorsal
valve of L. girtyi Walcott (Pl. LX-XIX, fig. 1r), and that two small central muscle scars are
midway between the posterior and anterior margins of the valve. ‘The average shell has a
width of 2 mm., with a length of from 1.5 to 1.75 mm.

L. transversa differs by its transverse outline from all other known species of the genus.

ForMATION AND LOCALITY.—Upper Cambrian: (30j) About 950 feet (289.6 m.) above the Middle Cambrian and
2,450 feet (746.8 m.) below the top of the Upper Cambrian, near the base of the arenaceous shales and limestone forming
le of the Orr formation [Walcott, 1908f, p. 176], on Orr Ridge, about 5 miles (8 km.) south of Marjum Pass, House
Range [Walcott, 1908f, Pl. XIII], Millard County, Utah.

LINNARSSONELLA URANIA Walcott.
Plate LX XVIII, figures 9, 9a-c.

Linnarssonella wrania Waucort, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, pp. 92-93, Pl. IX, figs. 9 and 9a. (De-
scribed and discussed as below as a new species. Figs. 9 and 9a are copied in this monograph, Pl. LXXVIII,
figs. 9a and 9c, respectively.)

Shell minute, general form elongate oval. Ventral valve convex; apex minute and curved
down nearly to the plane of the margin of the valve; false area, if present, must be very narrow.

ACROTRETIDA. 671

Pedicle opening situated on the umbo a short distance above the point of the beak; on some
shells it opens on the plane of the surface of the valve, and on others it has a rounded, slightly
elevated margin. Dorsal valve slightly convex, with a minute beak at the posterior margin.
Surface of the shell glossy, with very fine concentric striz and lines of growth. A ventral valve
2.5 mm. in length has a width of 1.75 mm. The dorsal valves are somewhat shorter in propor-
tion to the width.

A partial cast of the interior of the ventral valve shows a small visceral area in front of the
pedicle opening. The interior of the dorsal valve is marked by a strong central ridge that
extends from the beak four-fifths of the distance to the front margin; on each side of the median
ridge, near the posterior margin, there is a rather large, clearly defined cardinal muscle scar.

Observations.—This species differs from ZL. girty2 Walcott in not having a false area in the
ventral valve, and also in the position of the pedicle opening. The incurved apex is more like
L. modesta, but the form of the ventral valve and the position of the pedicle aperture are quite
different.

ForMATION, AND LOCALITY.—Middle Cambrian: (55u) Limestones about 200 feet (61 m.) above the Lower Cam-

brian [see Walcott, 1908f, p. 171], 0.25 mile (0.4 km.) below the Maxfield mine, in Big Cottonwood Canyon, on the
west front of the Wasatch Mountains, southeast of Salt Lake City, Salt Lake County, Utah.

Genus ACROTRETA Kutorga.¢
[axpoc, at the top; and zpnzéc, bored through.)

Acrotreta Kutorea, 1848, Verhand]. Russ.-kais. min. Gesell. St. Petersburg for 1847, No. 12, pp. 259 and 260 (notes
"on genus), and p. 275 (described in German as a new genus; see p. 672 for translation).
Acrotreta Kutorga, Morris, 1849, Annals and Mag. Nat. Hist., 2d ser., vol. 4, pp. 316 and 318. (Characterized and
discussed.)
Acrotreta Kutorga, Davison, 1853, British Fossil Brachiopoda, vol. 1, Introduction, No. 3, p. 133. (Described and
discussed as a possible subgenus. )

a The synonymy for this genus does not give a complete record of the various genera under which the species now included in Acrotreta were
formerly placed; it gives only those references in which the genus is discussed or described. To complete the record the following mere generic
references are listed:

Discina Shumard [1861, p. 221).
Acrotreta Billings [1865a, p. 216].
Obolella Salter [1866, p. 285].
Discina Salter [1866, p. 285].
Obolelia Hartt [1868, p. 644].

Lingula Barrande [1868a, p. 102; 1868b, p. 692).

Obolella Davidson [1868, pp. 309 and 310].
Acrotreta ? Davidson [1868, p. 314].
Obolella Davidson [1871, pp. 339 and 340).
Obolelia ? Billings [1872b, p. 470].
Acrotreta Meek [1873, p. 463].

Obolelia ? Billings [1874, p. 69].
Metoptoma Callaway [1874, p. 196].
Acrotreta White [1874, p. 9].

Acrotreta Linnarsson [1876, p. 16].
Obolella Linnarsson [1876, p. 19].
Acrotreta Linnarsson [1877, p. 374].
Acrotreta White [1877, p. 53].

Obolella Callaway [1877, p. 669].

Acrotreta Swanston [1877, Pl. VII figs. 21a-c).
Obolella Hartt [1878, p. 644].

Oboleila Linnarsson [1879, p. 27].

Obolus ? Barrande [1879b, Pl. XCV: ul].
Acrotreta Barrande [1879b, Pl. XCV: vm].
Acrotreta Brogger [1882, pp. 45 and 46].
Obolella Davidson [1883, p. 211).

Acrotreta Davidson [1883, p. 213}.

Obolella Walcott [1884a, p. 16].

Obolella ? Walcott [1884b, Pl. I, fig. 1c].
Acrotreta Walcott [1886b, p. 98].
Lingulella ? Matthew [1886, p. 33).
Acroatreta Matthew [1886, p. 36].

Acrotreta Swanston [1886, Pl. VII, figs. 21a-c].
Linnarssonia Walcott [1887, p. 189].
Linnarssonia Gehlert [1889, p. 1138).
Linnarssonia Walcott [1889b, p. 36].
Obolelia Dawson [1888a, p. 55; 1888b, p. 55).
Acro! Waleott [1889c, p. 441).

Linnarssonia Walcott [1889c, p. 442].

Obolella (Linnarssonia) Dawson [1890, p. 53].

Linnarssonia Hall [1890, p. 55].

Obolella Hartt [1891, p. 644].

Acrotreta Walcott [1891a, p. 608).

Linnarssonia Walcott [1891a, p. 616 and Pl.
LXVIII, figs. 2a-d].

Obolelia Hall and Clarke [1892c, p. 103].

Acrotreta Matthew [1892, p. 43; 1894, p. 87].

Linnarssonia Matthew [1895a, p. 125].

Acrotreta Matthew [1895a, p. 126].

Lingulella ? Matthew [1895a, p. 127].

Obolella Wallerius [1895, p. 65].

‘Acrotreta Wallerius [1895, p. 66].

Linnarssonia Matthew [1897, p. 169].

Linnarssonia Schuchert [1897, p. 262].

Linnarssonia Frech [1897; Pl. 1A, figs. 3a and 3b).

Linguletla ? Matthew [1898a, p. 128].

Acrotreta Walcott [1899, p. 449].

Acrotreta Matthew [1901a, p. 275].

Acrothyra ? Matthew [1901b, p. 304].

Acrotreta Matley [1902, p. 142].

Acrotreta? Matley [1902, p. 143].

Acrotreta Matley [1902, p. 144].

Linnarssonia Matley [1902, p. 145].

Lingulella (Acrothyra ?) Matthew [1902b, p. 390).

Acrothele Matthew [1902b, p. 404].

Acrotreta Matthew [1902c, p. 109].

Acrotreta Walcott [1902, pp. 580-600).

Acrotreta Wiman [1902, pp. 54 and 55).

Obolella Wiman [1902, p. 66].

Acrothele Matthew [1903, p. 103].

Acrotreta Walcott [1905a, pp. 298-303].

Acrotreta Moberg and Segerberg [1906, pp. 64, 65,
and 66].

Acrotreta Walcott [1908c, p. 245; 1908d, pp. 93, 94, 95,
and 96].

672 CAMBRIAN BRACHIOPODA. ’

Acrotreta Kutorga, voN SEEBACH, 1865, Zeitschr. Deutsch. geol. Gesell. for 1865, Bd. 17, Hft. 2, p.341. (Discussed
in German.)

Acrotreta Kutorga, Davison, 1871, British Fossil Brachiopoda, vol. 3, pt. 7, No. 4, p. 343. (Mentioned in discussion
of Acrotreta nicholsoni.)

Acrotreta Kutorga, Dawu, 1877, Bull. U.S. Nat. Mus. No. 8, p. 12. (Mentioned.)

Acrotreta. Kutorga, ZitrEL, 1880, Handbuch der Pal:eontologie, Bd. 1, Abth. 1, p. 666. (Described in German.)

Acrotreta Kutorga, Waucorr, 1884, Mon. U.S. Geol. Survey, vol. 8, pp. 16-17. (Discussed.) k

Linnarssonia WaLcott, 1885, Am. Jour. Sci., 3d ser., vol. 29, p. 115. (Wescribed and discussed as a new genus.)

Linnarssonia Walcott, MartHEw, 1886, Trans. Roy. Soc. Canada for 1885, Ist ser., vol. 3, sec. 4, No. 4, p. 35.
(Discussed.)

Acrotreta Kutorga, OEHLERT, 1887, Manuel de conchyliologie, by Fischer, p. 1266. (Described in French, with
figures of ‘‘ A. subconica.’’)

Linnarssonia Walcott, Dawson, 1890, Trans. Roy. Soc. Canada for 1889, Ist ser., vol. 7, sec. 4, No. 3, pp. 53-54.
(Mentioned in discussion of Acrothele pretiosa.)

Acrotreta Kutorga, Hatt and CrarKkn, 1892, Eleventh Ann. Rept. State Geologist New York for 1891, p. 250.
(Described.) i

Linnarssonia Walcott, Hatt and CLARKE, 1892, idem, p. 251. (Described.)

Acrotreta Kutorga, Haun and CuarKe#, 1892, Forty-fifth Ann. Rept. New York State Museum for 1891, p. 566. (Copied
from Hall and Clarke, 1892a, p. 250.)

Linnarssonia Walcott, Hatt and CuarKe, 1892, idem, p. 567. (Copied from Hall and Clarke, 1892a, p. 251.)

Acrotreta Kutorga, Hatt and CiarKe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, pp. 101-104.
(Described and discussed.)

Linnarssonia Walcott, Hatt and CLARKE, 1892, idem, pp. 107-109. (Described and discussed.)

Linnarssonia Walcott, MatrHEw, 1892, Trans. Roy. Soc. Canada for 1891, Ist ser., vol. 9, sec. 4, No. 5, p. 42. (Species
referred to the genus mentioned.)

Acrotreta Kutorga, MartHew, 1902, Bull. Nat. Hist. Soc. New Brunswick, vol. 4, pt. 5, No. 20, p. 390. (Stratigraphic
range in Cape Breton discussed.)

Acrotreta Kutorga, Matraew, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, p. 94. (A copy ot
the preceding reference.)

Acrotreta Kutorga, MartHew, 1903, idem, pp. 96-97. (Notes on development of the genus.)

Acrotreta Kutorga, GRABAU and Sumer, 1907, North American Index Fossils, vol. 1, p. 199. (Described.)

2 Linnarssonia GRABAU and SHER, 1907, idem, p.200. (Described, but the only species referred to the genus (“‘L.
pretiosa”’) is not figured and it is impossible to tell whether the authors are discussing the Limnarssonia pretiosa
that has been referred to the genus Acrotreta (Acrotreta sagittalis), or to the genus Acrothele (Acrothele pretiosa).)

Acrotreta Kutorga, Watcort, 1908, Smithsonian Misc. Coll., vol. 538, No. 4, Pl. XI, and pp. 142 and 146. (Classifica-
tion of genus.)

The original description by Kutorga follows:

Dorsal valve highly conical; the hinge surface of the cone flat, in the form of a high triangle, similar to an area,
with a shallow gutter-shaped depression running from the tip as far as the middle point, which (depression) here
appears as an indication of a deltidium. At the upper end of this furrow, turned consequently to the hinge side, is
found the obtusely oval external siphonal opening.

Ventral valve flat, with a distinct marginal apex. On the surface of the shell are seen only delicate growth wrinkles
concentric to the apex of the cone, which curve crescentially into the longitudinal furrow of the surface of the shell;
no tubercles and no spines; hinge border rectilinear.

The revised description of the genus is as follows: Ventral valve strongly convex to conical,
with the posterior face more or less flattened to form a false area that is usually marked by a
shallow median groove. Pedicle opening at the apex of the cone and directed more or less
backward. Apex usually anterior to the posterior margin, but occasionally overhanging it.
Dorsal valve slightly convex, with very small beak; area short and divided by a small false
deltidium.

Surface marked by fine concentric striz and limes of growth which cross the posterior face
and the median groove; in addition there are on five species very fine, concentric, undulating,
often inosculating, rounded ridges that form a surface like that of Obolus ( Westonia) ella (Hall
and Whitfield) (Pl. XLVII, fig. 10). <Acrotreta primeva Walcott (Pl. LXIX) has this type
of surface. A. claytoni Walcott (Pl. LX XIV) has fine, undulating striz, A. spinosa Walcott
(Pl. LX XIX) fine short spines, and A.? cancellata Walcott (Pl. LX XIX) a cancellated surface.
The shell in all species where it is preserved is calcareocorneous and built up of several thin
layers or lamelle that are arranged more or less obliquely to the outer surface toward the outer
margin of the valves.

———

a

ACROTRETIDA. 673

The cast of the ventral valve shows that the interior of the shell has a rather strong cal-
losity or apical swelling penetrated by the foraminal tube, and on each side of and back of the
callosity near the posterior margin the cardinal muscle scars, which usually take the form
of a projecting boss or tubercle corresponding to a depression in the shell in which the trans-
median and middle lateral muscles were probably attached. In front of the apical callosity in
A. argenta Walcott there are two trapezoidal areas corresponding to similar areas in Obolella
and Obolus, 1 which the central, outside, and middle lateral muscles were attached. The
position and size of the areas are shown by Plate LXVII, figures 5a and 5b. The grooves of
the main vascular sinuses pass around the apical swellmg and extend forward, diverging toward
the anterolateral margins of the shell.

The interior of the dorsal valve is almost invariably marked by a long, well-defined median
ridge and a pair of strong cardinal tubercles near the margin of the area corresponding in
position to the cardinal tubercles of the ventral valve. Smaller tubercles occur in advance
of the posterior tubercles, one on each side of the median ridge; they are often replaced by elon-
gate oval scars that correspond to the central scars of the dorsal valve of Obolus; the anterior
lateral muscle scars are too minute to be clearly located, but they were undoubtedly close to
the median line a little in advance of the central scars. The cardinal tubercles of both valves
often have scars on them indicating the attachment of muscles.

Type.—Acrotreta subconica Kutorga.

_ Observations —Of the type of the genus, A. subconica Kutorga, only the external shell is
known. In 1884 [1884b, Pl. I, figs. 1b and 1d] I illustrated the interior of both valves of ‘A.
gemma”’ (see pp. 80-31), showing the area, median ridge, ‘‘cardinal tubercles,” and central muscle
tubercles of the dorsal valve, and the apical swelling and cast of the main vascular canals in the
ventral valve. Matthew [1886, Pl. V, figs. 13 and 13c] illustrated the interior of A. baileyi,
showing the cast of a small tubercle on each side of the apical swelling. Hall and Clarke [1892c,
p- 102] stated that they could not see the cast of these tubercles on the original specimen, and I
have not been able to find them on any of the type specimens of A. baileyi received from Mat-
thew. It frequently occurs that the casts of the short deep channel of the main vascular
sinuses give rise to tubercles a little in advance of and close to the apical callosity (Pl. LXX, fig.
1f), or it may be that the cast of the visceral cavity will take the form of tubercles in front of
the cast of the apical callosity (Pl. LXIV, fig. 2c).

The intimate relations existing between Acrotreta and Linnarssonia became more and more
apparent with the collection of better material representing the two species referred to the two
genera. Girty, when selecting specimens for illustration, called my attention to the strong
resemblance between them and suggested that Linnarssonia was a synonym of Acrotreta. In
all essential characters this is true, and Linnarssonia, if retained at all, must be as a subgenus to
include the depressed forms of Acrotreta, intermediate between the typical elevated species A.
subconica Kutorga and A. gemma Billings and the nearly flattened shells of Acrothele. In view,
however, of the close similarity of the interiors of the valves of Acrotreta schmalenseei Walcott,
A. curvata Walcott, and A. kutorgai Walcott to “Linnarssonia transversa”’ (see Acrotreta sagitta-
lis transversa (Hartt)), ““L.” sagittalis (Salter), and “L.”’ misera (Billings) there remains only
the external form of the pedicle valve to distinguish the two genera; this latter character is
not of generic importance in the presence of the gradation in elevation and outline between
A. subconica Kutorga and A. sagittalis transversa (Hartt), shown by A. idahoensis Walcott, A.
schmalenseer Walcott, A. microscopica (Shumard), A. pyxidicula White, and A. sagittalis (Salter).

When studying the specimens of Acrotreta at hand in 1884 I believed that A. gemma
Billings, of Newfoundland, included the western forms described by Meek [1873, p. 463] and
White [1877, p. 53]. This conclusion was retained until the study of a large series from each of
the typical localities convinced me that there were a number of species and varieties grouped
under A. gemma. ‘The correct reference of these species and varieties is indicated in the table,
pages 30-31, and taken up in detail in the synonymy of each of the different species.

62667°—vot 51, pr 1—12—43

674 CAMBRIAN BRACHIOPODA.

“ Acrotreta? costata’’ Davidson [1883, p. 213] from the Llandeilo of Scotland does not appear
to be an Acrotreta. The description and figures suggest a genus allied to Cyrtia Hall and Clarke
[1894, p. 40] of the Silurian.

The surface characters of Acrotreta have been considered to be very simple and confined
to concentric lines and striz of growth and obscure radiating striz. This study of the species
has resulted in the discovery that five species, A. bisecta Matthew, A. gemmula Matthew, A.
inflata (Matthew), A. promeva Walcott, and A. sabrine (Callaway), have a surface much like
that of Obolus (Westonia) ella (Hall and Whitfield) (Pl. XLVII). Mention has been made of
the cancellated and spinose species, and those with undulating concentric strie. It is evident
that Acrotreta, like Acrothele and Micromitra, has varied surface characters that are of specific
but not generic value.

The false area, with or without its vertical median groove, is a variable character. The
area and median groove are well developed in the type A. subconica Kutorga (Pl. LXXIII,
figs. 2¢, 2h) and in the species A. socialis v. Seebach (Pl. LX XIII, figs. 4’, 4a’). On A. attenuata
Meek a narrow sharp furrow is present, but the false area is scarcely defined (Pl. LXIV, figs.
1b’’, 1¢e’’, 1d’’). On A. idahoensis Walcott the false area is clearly defined but there is scarcely
a trace of the median furrow (Pl. LXV, figs. 1’’, la’’-c’’). On A. microscopica (Shumard) (Pl.
LXVII, figs. 1a’—c’) there is only a faint false area and no median groove.

The vascular markings, muscle scars, and apical callosity of the ventral valve vary in
relative size, position, and appearance, but they all have a common general character and
position. Usually the markings on the interiors of the valves are very faint, and often nothing
can be seen but the apical callosity and.the base of the main vascular sinuses in the ventral
valve, and the median ridge in the dorsal valve. It would require many pages on which to
record the variations, and.as they are illustrated by the figures on the plates I will not attempt it.

Geographic distribution.—The little shell of Acrotreta occurs in every country where any

considerable development of the Cambrian fauna is known. The exceptions are northern .

India, Australia, and where the Lower Cambrian fauna predominates. The general distribu-
tion is giyen on pages 105-106.

Stratigraphic. distribution.—Three species and one variety are known from the Lower
Cambrian, one of which, A. primzva Walcott (Pl. LXIX, figs. 1, 1a-f), is one of the largest
species of the genus. From the Middle Cambrian thirty-three species and ten varieties are
known; they range from the base of the terrane to its summit, and two, A. zdahoensis Walcott
and its variety alta and A. pyzidicula White, pass up into the Upper Cambrian, and the first
species and its variety alta continue on up into the base of the Ordovician in Nevada. In the
Upper Cambrian twenty-one species and three varieties are known and in the passage beds above
seven species. In the Lower Ordovician seven species and one variety occur, of which one
species and one variety also occur in the Cambrian. The stratigraphic range of the species is
given on pages 105-106.

ACROTRETA ARGENTA Walcott.

Plate LXVII, figures 5, 5a-g.
Acrotreta argenta Waucott, 1902, Proc. U. 8. Nat. Mus., vol. 25, pp. 580-581. (Described as below as a new species.)

The material representing this species is more or less crushed and broken, but a few speci-
mens show the general form and characters. It belongs to the Acrotreta idahoensis Walcott
group in having a wide false area, strongly marked apical callosity, and pedicle opening. The
thickening in the posterior portion of the dorsal valve is also characteristic of the two species.

The cast of the interior of a ventral valve (Pl. LX VII, fig. 5b) reveals what I have searched
for unsuccessfully in hundreds if not thousands of specimens of this genus. I refer to the
visceral area with the position of the point of attachment of the central and lateral muscles on
each side of it, essentially as in Obolella and Obolus (Pl. VII).

FoRMATION AND LOCALITY.—Upper Cambrian: (7x and 7y) Limestone of the Emigrant formation [Turner, 1902,
p. 265], about 2.5 miles (4 km.) southeast of Emigrant Pass; (8b’) shales of the Emigrant formation [ Turner, 1902, p. 265],

|

ACROTRETIDA. 675

in a ravine on the east side of the road about 1 mile (1.6 km.) southwest of Emigrant Pass; and (7v) shales of the Emigrant
formation [Turner, 1902, p. 265], 4.25 miles (6.8 km.) south-southeast of Emigrant Peak; all in the Silver Peak quad-
rangle (U. 8. Geol. Survey), Esmeralda County, Nevada.

ACROTRETA ATTENUATA Meek.

Plate LXIV, figures 1, la-o; Plate LX XIX, figures 6, 6a.

Acrotreta attenuata MEEK (in part), 1873, Sixth Ann. Rept. U.S. Geol. and Geog. Survey Terr. for 1872, p. 463, footnote.
(Listed as A. subconica Kutorga, and described in footnote as a possible new species. Specimens now referred
to A. attenuata var.? and A. idahoensis were also included in this reference.) ;

Acrotreta gemma Waxcorr (in part) [not Brntinas], 1884, Mon. U. 8. Geol. Survey, vol. 8, pp. 17-18. (Specimens
representing Acrotreta pyxidicula, A. curvata, and A. idahoensis alta were included with the specimens repre-
senting A. attenwata when this description of A. gemma was written, but only the last two are known to have
been figured: A. curvata, Pl. I, figs. 1d and le; and A. idahoensis alta, Pl. I, figs. la and 1b. The specimens
represented by Pl. IX, figs. 9 and 9a, can not be found at this time, but it is probable that they should be
referred to A. idahoensis alta. Fig. le represented a specimen of Acrotreta sabrine, and the specimen repre-
sented by fig. 1f is missing.) ;

Acrotreta gemma Watcort (in part) [not Brztrves], 1886, Bull. U. S. Geol. Survey No. 30, pp. 98-99. (Specimens
now referred to Acrotreta pyxidicula and A. primxva were included with the specimens representing A. attenuata
when this description of A. gemma was written, A. primxva being figured, Pl. VIII, figs. 1, la-b.)

Acrotreta gemma Watcort (in part) [not Bruxines], 1891, Tenth Ann. Rept. U. S. Geol. Survey, p. 608. (Specimens
now referred to Acrotreta pyxidicula, A. curvata, A. idahoensis alta, and A. primxva were included with the
specimens representing A. attenuata in this reference to A. gemma, the last three being figured: A. curvata,
Pl. LXVII, fig. 5b; A. idahoensis alta, Pl. UXVII, figs. 5 and 5a; and A. primezva, Pl. LX VII, figs. 5c, 5d, and 5e.)

Acrotreta gemma Waxcorr (in part) [not Brxxtnes], 1899, Mon. U. S. Geol. Survey, vol. 32, pt. 2, p. 449. (Specimens
now referred to Acrotreta pyxidicula, A. curvata, A. idahoensis alta, and A. primxva were included with the
specimens representing A. attenuata when this description of A. gemma was written, the last three being figured:
A. curvata, Pl. LXII, fig. 2e; A. idahoensis alta, Pl. LXII, figs. 2a and 2c; and A. primeva, Pl. LXII, figs. 2,
2b, and 2d.) '

Acrotreta attenuata Meek, Waxcort, 1905, Proc. U.S. Nat. Mus., vol. 28, p. 298. (Characterized.)

The variations in the exterior form of the ventral valve of this species are so fully shown
by the illustrations that it is unnecessary to enter into*detailed description. The species is
characterized by its elevated ventral valve and narrow, incurved false area. The specimens
illustrated by Plate LXIV, figures 1, 1a, 1b, and 1h, are from the material labeled by Meek as
Acrotreta attenuata, and all the others are from the same geological area. Some of the forms of
A. idahoensis alta (Pl. LXV, fig. 4) look like A. attenuata, but the false area is different. Acro-
treta kutorgai has a somewhat similar false area and elevation, but it is a less robust shell and
the apex of the ventral valve is nearer the posterior margin. The former reference to A. gemma
is explamed under the description of the genus (p. 673). Shells with a distinctly marked false
pedicle groove in the ventral valve occur in the shales of the Wheeler formation of the Middle
Cambrian of the House Range, Utah. The shells of this locality show fine mteriors of both
valves (Pl. LXIV, figs. li-n, and Pl. LX XIX, figs. 6, 6a). The interiors of the ventral valve
are much like those of A. kutorgai Walcott (Pl. LXV, figs. 3b, 3c).

FORMATION AND LOCALITY.—Upper Cambrian: (61) Limestone in the Dunderberg shale [Walcott, 1908f, p. 184],
a little south of the Hamburg mine, Eureka district [Hague, 1892, Atlas], Eureka County, Nevada.

Middle Cambrian: (59) Limestone at the base of the western slope of Combs Peak, near the plain of Antelope
Valley, Eureka district [Hague, 1892, Atlas], Eureka County, Nevada.

(3s) About 1,700 feet (518.2 m.) above the Lower Cambrian and 2,700 feet ($23 m.) below the Upper Cambrian in
the shaly limestones and calcareous shales of the Wheeler formation [Walcott, 1908f, p. 181] in the eastern part of
Wheeler Amphitheater, east of Antelope Springs, House Range [Walcott, 1908f, Pls. XIII and XV]; (10y) about 2,900
feet (884 m.) above the Lower Cambrian and 1,500 feet (457.2 m.) below the Upper Cambrian im the central part
of the limestone forming 1a of the Marjum limestone [Walcott, 1908f, p. 179], about 1 mile (1.6 km.) south-southwest of
Marjum Pass, House Range [Walcott, 1908f, Pl. XII1]; and (8x) about 2,200 feet (670.6 m.) above the Lower Cambrian
and 2,200 feet (670.6 m.) below the Upper Cambrian in the shaly limestones forming 1d of the Marjum limestone
[Walcott, 1908f, p. 180], 2.5 miles (4 km.) east of Antelope Springs, in ridge east of Wheeler Amphitheater, House
Range [Walcott, 1908f, Pls. XIII and XV]; all in Millard County, Utah.

(9h) At the base of the limestone above the Wolsey shale [Walcott, 1908f, p. 202] on Beaver Creek, 5 miles (8 km.)
north of York, and about 8 miles (12.8 km.) north of Canyon Ferry, Big Belt Mountains, Fort Logan quadrangle (U.S.
Geol. Survey), Meagher County; (159) limestones north of West Gallatin (Gallatin) River, Gallatin County; (302)

676 CAMBRIAN BRACHIOPODA.

limestones on the east side of West Gallatin (Gallatin) River, above Gallatin, Gallatin County; and (156a) limestones
of the Flathead formation of Peale, north of East Gallatin River, near Hillsdale, Gallatin County; all im Montana.

(4n) Limestone about 325 feet (99.1 m.) above the unconformable base of the Cambrian in divide at the head of
Jackson Creek (locally known as Sheep Creek), a creek flowing into Jackson Lake about 0.5 mile (0.8 km.) south of its
northwest corner, Teton Mountains, Grand Teton quadrangle (U. 8. Geol. Survey), Uinta County; and (840d) lime-
stone near the head of Bear River Canyon; both in Wyoming.

ACROTRETA ATTENUATA var.? Walcott.

Plate LXV, figure 2.

Acrotreta attenuata MrrEx (in part), 1873, Sixth Ann. Rept. U.S. Geol. and Geog. Survey Terr. for 1872, p. 463, footnote.
(These specimens were included by Meek with the specimens which he listed as Acrotreta subconica and described
in a footnote as A. attenuata. See also A. attenuata and A. idahoensis.)

Acrotreta attenuata Meek, var.?, Watcort, 1905, Proc. U. 8. Nat. Mus., vol. 28, p. 298. (Reason given for separation as
variety.)

A shell with a distinctly marked false area is separated as a variety of Acrotreta attenuata.
It is associated with the type specimen of A. attenuata.

ForMATION AND LOCALITY.—Middle Cambrian: (302) Limestone east of West Gallatin (Gallatin) River, above

Gallatin, Gallatin County, Montana.

ACROTRETA BABEL Barrande.
aa Plate LX XVII, figures 6, 6a—b.

Acrotreta babel BARRANDE, 1879, Systéme silurien du centre de la Bohéme, vol. 5, pt. 1, Pl. XOCV, figs. vu: 1-2. (Not
described, but figured as a new species. Figs. 2A, 2B, and 2C are reproduced in this monograph, Pl. LX XVII,
figs. 6, 6a—b, respectively.)

This minute species is the only form of this genus that has been identified from Bohemia
by Barrande. It has the characters of the genus, and with the figures for comparison with
other species it appears to be distinct from all others. Barrande [1879b, Pl. XCV, fig. vir: 1]
illustrates a more conical shell from Trubin than that represented by figures 6 and 6a, which
may belong to another species and genus.

ForMATION AND LOCALITY.—Lower Ordovician: (303) Etage d3, Kénigshof; and (308a) Etage d3, Trubin; both
[Barrande, 1879b, Pl. XCV] in Bohemia, Austria-Hungary.

ACROTRETA BAILEYI Matthew.

ly,
x Plate LX XVII, figures 2, 2a-d.

Acrotreta baileyi MatrHEw, 1886, Trans. Roy. Soc. Canada for 1885, Ist ser., vol. 3, sec. 4, No. 4, pp. 36-37, Pl. V,
figs. 13, 13b-d. (Described and discussed as a new species. The specimens represented by figs. 13, 13c, and
13d are redrawn in this monograph, Pl. LX XVII, figs. 2a, 2, and 2’, respectively.)

Acrotreta baileyi Matthew, Haut and Ciarxe, 1892, Eleventh Ann. Rept. State Geologist New York for 1891, Pl. III,
figs. 28-30. (Figs. 28 and 30 are drawn irom the specimens figured by Matthew, 1886, Pl. V, figs. 18c and 13,
respectively.)

Acrotreta baileyi Matthew, Hai and Crarxe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, p. 102, Pl. III,
figs. 32-34. (Discussed. Figs. 32-34 are copied from figs. 28, 30, and 29 of the preceding reference.)

Not Acrotreta baileyi? MatrHew, 1892, Trans. Roy. Soc. Canada for 1891, Ist ser., vol. 9, sec. 4, No. 5, p. 43, Pl. XII,
fig. 7d (referred to A. bisecta).

Acrotreta baileyi MartHEw, 1902, Bull. Nat. Hist. Soc. New Brunswick, vol. 4, pt. 5, No. 20, p. 395, Pl. XVI, figs.
la-d. (Mentioned and dimensions given. Figs. copied from Matthew, 1886, Pl. V, figs. 13, 13b-d.)
Acrotreta baileyi Matthew, Waxtcort, 1902, Proc. U. S. Nat. Mus., vol. 25, pp. 581-582. (Described and discussed

as below.)

Acrotreta baileyi MatrHEw, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, p.97, Pl. III, figs. lad.
(Mentioned. Figures are copied from Matthew, 1886, Pl. V, figs. 18, 13b-d.)

General outline transversely oval, with the posterior margin more or less straight for less
than one-half the transverse diameter of the shell. On the ventral valve the posterior margin
is rounded in at the median furrow of the false area, and on the dorsal valve it curves gently
from the cardinal slopes to the beak. ;

The ventral valve is strongly convex with the apex about one-fourth the length of the
valve from the posterior margin. The crushed condition of the shells does not permit

ACROTRETID. 1 ONT

decision as to whether the umbo or the apex is the most elevated part of the valve. False
area defined by the incurving of the cardinal slopes so as to form a somewhat flattened, trian-
gular space that is divided midway by a rather strong vertical furrow. Pedicle aperture
rather large and opening obliquely backward. The dorsal valve is gently convex, with a
minute marginal beak.

Surface of shell marked by fine concentric striz and lines of growth, and possibly by fine
radiating striz. I fail to find any traces of the radiating striz on specimens that have not
been distorted by pressure, and it looks as though all radiating striz and lines are the result
of lateral compression of the shell. The average length is about 3.5 mm.; width,4mm. (Dis-
torted shells have a length of 4 mm.; width, 3 mm.)

The cast of the interior of the ventral valve shows a strong apical callosity, a fair-sized
pedicle opening, large cardinal scars, and a small visceral area in front of the apical callosity.
Matthew [1886, p. 36, Pl. V, fig. 13c] describes and shows on his illustration two ‘‘minute
muscle scars” close to the “‘umbonal tubercle’? and on each side of the parallel striz. On
one specimen I find what may have led Matthew to consider there were such scars, but on
many others quite as well preserved there are no such indications, and they are not known
in any other species of the genus. Hall and Clarke examimed Matthew’s type material, and
stated [1892e, p. 102] that with the original material before them they were unable ‘‘to dis-
tinguish anything more than the central callosity.”. The cast of the imterior of the dorsal
valve shows a strong median ridge of variable length and size, large cardinal scars, and well-
defined central scars.

Observations.—This species belongs with the series represented by A. sagittalis (Salter)
and its varieties, and if uncompressed, nondistorted, well-preserved specimens could be obtained,
it is quite possible that it would prove to be identical with A. sagittalis transversa (Hartt).
Matthew [1886, p. 37] thinks it has a thinner shell, but that is not probable, as the apical
callosity and cardinal sears of the ventral valve and the median ridge, cardinal and central
sears of the dorsal valve all indicate a shell quite as thick as that of A. sagittalis and its varieties.

Doctor Matthew kindly sent me the type and study material of this species from his private
collection.

FORMATION AND LOCALITY.—Middle Cambrian: (300) Shaly sandstones, possibly of Division 1d of Matthew, on

Long Reach, Kings County; and (301) doubtfully in sandstones of Division 1b2 of the ‘‘Protolenus zone” [Matthew,
1895a, p. 108] Hanford Brook, St. John County; both [Matthew, 1886, p. 37] in New Brunswick, Canada.

ACROTRETA BELLATULA Walcott.

Plate LX XVIII, figures 4, 4a-d.

Acrotreta bellatula Watcort, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, pp. 93-94, Pl. IX, figs. 4, 4a-b. (Described
and discussed as below as a new species. Figs. 4, 4a—b are copied in this monograph, Pl. LX XVIII, figs. 4,
4b, and 4d, respectively.)

General outline subcircular to transversely broad oval, with the posterior margin of the
ventral valve nearly straight beneath the false area. The ventral valve is: moderately convex,
with the apex a little in front of the posterior margin. False area defined by the incurving
of the cardinal slopes so as to form a somewhat flattened triangular space that is divided mid-
way by a narrow and rather shallow, vertical furrow; pedicle aperture of medium size and
opening slightly backward. Dorsal valve nearly as convex as the ventral, except that it curves
down in the posterior portion to a minute marginal beak.

Surface of the shell marked by fine, concentric striz and lines of growth that show marked
variations in their sharpness on different specimens, the older shells having a dark, dull sur-
face giving the effect of a thin film over the striz; a few traces of radiating striz are shown on
some shells.

The average length of the larger shells is about 1.75 mm.; width, 2 mm.

The interior of the ventral valve shows a small apical callosity, minute pedicle tube, and
vascular sinuses originating a little back of the apical callosity; a cast shows that there were

678 ! CAMBRIAN BRACHIOPODA.

medium-sized, elevated cardinal muscle scars. An interior cast of the dorsal valve indicates
a median ridge that extended about four-fifths of the distance from the area to the front mar-
gin. It also indicates medium-sized, elevated cardinal muscle scars. A second specimen
shows a shorter median ridge, with small, elevated central muscle scars about halfway between
the posterior and front margins of the shell.

Observations.—This species belongs to the Acrotreta sagittalis (Salter) group. The low
convexity of the ventral valve, posterior position of the apex, the strong cardinal muscle
scars, and the strong median ridge, and the cardinal and central scars of the dorsal valve, are
all features common to Acrotreta bellatula and A. sagittalis. It differs from A. sagittalis in
the more posterior position of the apex and less convexity of the ventral valve, and from
A, definita Walcott in its much smaller size and less elevated ventral valve.

ForMATION AND LOCALITY.—Middle Cambrian: (10z) About 2,900 feet (884 m.) above the Lower Cambrian and
1,500 feet (457.2 m.) below the Upper Cambrian in ta of the Marjum limestone [Walcott, 1908i, p. 179]; (11m) a horizon
about 100 feet (30.5 m.) above (10z); and (8w) about 2,350 feet (716.3 m.) above the Lower Cambrian and 2,050 feet
(624.8 m.) below the Upper Cambrian in the central portion of 1c of the Marjum limestone [ Walcott, 1908f, p. 180],
in the long cliff about 2 miles (3.2 km.) southeast of Marjum Pass; both in the House Range [Walcott, 1908f, Pls. XIII
and XV], Millard County, Utah.

ACROTRETA BELTI (Davidson).

Mic a Plate LX XVII, figures 8, 8a.

Obolella belti Davipson, 1868, Geol. Mag., vol. 5, pp. 310-311, Pl. XV, figs. 25-27. (Described as below as a new
species. The specimens represented by figs. 25-27 are redrawn by Davidson, 1871, Pl. L, figs. 15, 17, and 16,
respectively, and the last two figures are copied in this monograph; see note accompanying the following reference.)

Obolella belti Davipson, 1871, British Fossil Brachiopoda, vol. 3, pt. 7, No. 4, pp. 340-341, Pl. L, figs. 15-17. (Copy
of preceding reference; figs. 15-17 are copied (with slight changes) from figs. 25, 27, and 26, respectively, of
the preceding reference. Figs. 16a and 17a are reproduced in this monograph, Pl. LX XVII, figs. 8 and 8a,
respectively.) ;

Obolella sagittalis belti Daviwson, 1871, idem, description of figures, opposite Pl. L. (Species placed as a variety
without explanation.)

Not Linnarssonia belti? MarrnEw, 1892, Trans. Roy. Soc. Canada for 1891, 1st ser., vol. 9, sec. 4, No. 5, pp. 42-48,
Pl. XII, figs. 7a-c. (This species is not specifically referred in this monograph.)

Linnarssonia belti (Davidson), Matnry, 1902, Quart. Jour. Geol. Soc. London, vol. 58, pt. 1, p. 145, figs. 17-18. (Char-
acterized.)

Not Linnarssonia cf. belti MatrHEw, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, pp. 209-210,
Pl. XVI, figs. 3a-c. (Copies Matthew, 1892, pp. 42-43, Pl. XII, figs. 7a-c. The species is not specifically
referred in this monograph.)

The original description by Davidson follows:

Shell small, less than a line in length by about 1 line in breadth; transversely oval; beak acuminated; front
broadly rounded. Valves moderately convex and marked by concentric lines of growth. The internal characters
agree pretty closely with those described in O. sagittalis.

Observations.—It is possible that with a good series of specimens of this species its relations
to other species might be more accurately determined than Doctor Davidson was able to do.
It is not probable that Acrotreta sagittalis (Salter) persisted into Lower Tremadoc time, but with
a genus where the specific characters are so limited and the variations within the same species
considerable it is exceedingly difficult to determine the specific relations of a form represented
by only a few not very good specimens. Acrotreta belti appears to belong to the A. sagittalis
group of forms, but for the present I think it is quite as well to leave it as a species.

FoRMATION AND LOCALITY.—Upper Cambrian: (305 [Davidson, 1871, p. 341]) Lower Tremadoc shales, Craig-y-dinas,
North Wales.

(804 [Matley, 1902, p. 145]) ‘‘Bronsil” shales at White Leaved Oak, Malvern Hills; and (804a [Groom, 1902,
p. 110]) ‘‘Bronsil” shales in the Malvern Hills; both between Herefordshire and Worcestershire, England.

ACROTRETA BISECTA Matthew.

Plate LXVI, figures 7, 7a-e.

Acrotreta baileyi ? Marrnmw, 1892, Trans. Roy. Soc. Canada for 1891, 1st ser., vol. 9, sec. 4, No. 5, p. 43, Pl. XII, fig. 7d.
(Characterized and discussed.)

Acrotreta bisecta MartHEw, 1901, Bull. Nat. Hist. Soc. New Brunswick, vol. 4, pt. 4, No. 19, pp. 275-276, Pl. V, figs.

5 5a-g. (Described and discussed as a new species.)

ACROTRETID. 679

Acrotreta bisecta MatrHew, 1902, Bull. Nat. Hist. Soc. New Brunswick, vol. 4, pt. 5, No. 20, p. 394, Pl. XVI, figs.
2a-g. (Mentioned and figures of preceding reference copied.)

Acrotreta sipo MatrHEw, 1902, idem, pp. 406-407, Pl. XVIII, figs. land 2. (Described and discussed as a new species.)

Acrotreta bisecta Matthew, Watcort, 1902, Proc. U. 8S. Nat. Mus., vol. 25, p. 582. (Described and discussed. )

Acrotreta sipo MarrnEw, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, pp. 185-186, Pl. XVIII,

figs. land 2. (Copy of Matthew, 1902a, pp. 406-407, Pl. XVIII, figs. 1 and 2.) F

Acrotreta bisecta MarruEw, 1903, idem, pp. 186-187, Pl. XI, figs. 5a-g. (Copy of Matthew, 1901, pp. 275-276, Pl. V,
figs. 5a-g. .

Auwatvain Bisoaie te Watcorr, 1905, Proc. U. 8. Nat. Mus., vol. 28, pp. 298-299. (Described and discussed as
below.)

Nearly all the ventral valves of this species are more or less compressed in the shale, thus
decreasing the true elevation. Matthew [1903, Pl. XI, fig. 5] illustrates a pointed, high, ventral
valve, but does not state whether or not the figure is diagrammatic. Some of the casts in the
shale indicate a sharply conical ventral valve. When the apex is broken off the cast of a
median apical callosity is seen, with the base of the cast of a medium-sized pedicle tube; the
cardinal scars are small and nearly concealed by the cast of the stron® main vascular sinuses.
There is considerable range of variation in the size and length of the median ridge of the dorsal
valve. One specimen (fig. 7d) shows a strong median ridge, cardinal and central scars, and
deeply excavated false deltidium. Surface marked by fine concentric strize and lines of growth
and very fine undulating striz that give the concentric striz a fretted appearance when examined
by a strong lens.

The most nearly related species appears to be A. sabrine (Callaway) of the Shineton
shales. Matthew [1902a, p. 406] has described a shell as ‘‘ Acrotreta sipo”’ that occurs with his
“Asaphellus fauna.” I am unable to detect any specitic differences between it and A. bisecta,
from the same area.

The specific name is due to the presence of a strong median ridge bisecting the dorsal valve.

FORMATION AND LOCALITY.—Upper Cambrian: (3q) Shale in Barachois Glen, 4 miles (6.4 km.) south of Little
Bras d’Or Lake; (101) shale on east bank of Barachois River, 6 miles (9.6 km.) from Little Bras d’Or Lake; (10c and
10d) shales on west side of Barachois River, 0.125 mile (0.2 km.) north of Boisdale Road, opposite McMullin’s place;
(10e, 10f, and 10g) shales on the east branch of Barachois River, 0.5 and 0.75 miles (0.8 and 1.2 km.), respectively,
north of the crossroad from Boisdale to Upper Leitches Creek; (10n) shale in ravine on east side of Barachois Glen,
3 miles (4.8 km.) from Barachois; (10h) shale on small east branch of Barachois River, 0.75 mile (1.2 km.) north of the
crossroad from Boisdale to Upper Leitches Creek; (13h) shale on east bank of Barachois River, 1.5 miles (2.4 km.)
north of Boisdale; (807a [Matthew, 1903, p. 186]) shales of Division C3c2 of Matthew, on McLeod Brook=Barachois
River; and (807 [ Matthew, 1903, p. 187]) shales of Division C3c of Matthew, on McLeod Brook=Barachois River; all in
eastern Cape Breton, Nova Scotia.

(308 [Matthew, 1892, p. 43]) Shales of Division C3c of Matthew at Navy Island, St. John Harbor, New Brunswick,
Canada.

ACROTRETA ?? CANCELLATA Walcott.
Plate LX XIX, figures 5, 5a.

Acrotreta ?? cancellata Waucorr, 1905, Proc. U.S. Nat. Mus., vol. 28, p. 299. (Characterized as below as anew species.)

V

The only specimen of this species in the collection has more the form of Micromitra than
Acrotreta. In its overhanging false area it suggests Acrothyra. Whatever the genus to which
it belongs may be, its cancellated surface serves to distinguish it from forms with which it
might otherwise be compared. The surface is formed by very fine, raised, concentric lines or
ridges of growth, crossed by sharp radiating lines, which are seen only between the concentric
lines.

FORMATION AND LOCALITY.—Passage beds between the Upper Cambrian and the Ordovician: (205) Siliceous
limestone on Roundtop Mountain, Hureka district [Hague, 1892, Atlas], Eureka County, Nevada.

_ ACROTRETA CARINATA (Segerberg MS.) Moberg and Segerberg.
Text figures 56A—D, page 680.

Acrotreta cf. socialis: BréacErR (in part), 1882, Die silurischen Etagen 2 und 8, pp. 46-47, Pl. X, figs. 2, 2a-b (not figs.
3-4, which are not referred in this monograph). (Described in German.)

Acrotreta carinata (SEGERBERG MS.) Moprre and SxGErBeERG, 1906, Medd. fran Lunds Geol. Faltklubb, Ser. B, No. 2
(Aftryck ur K. ‘Fysiografiska Sallskapets Handl., N. F., Bd. 17), p. 66, Pl. III, figs. 5a-c and 6. (Described
in Swedish as a new species; see p. 680 for translation. The figures are reproduced in this monograph a8
figs. 56A—D, p. 680.)

680 CAMBRIAN BRACHIOPODA.

The original description by Moberg and Segerberg follows:

The species differs from Acrotreta circularis, to which in other respects it is closely related, by its more even area,
sharply bounded on the sides. At the rectilinear posterior edge the area occupies about one-fourth of the cireumfer-
ence; that is to say, more than in the case of A. circularis. The apex is
also placed somewhat nearer the posterior edge than in the last-named
species. The smaller shell is only feebly arched, with marginal, some-
what overlapping umbo.

By its large well-marked keeled area our species resembles A.
socialis, from the Ceratopyge limestone of Norway.

Observations—This species has about the same size
and general appearance as Acrotreta seebachi. It differs
from it in the more anterior position of the apex and the
strongly defined false area with a median ridge.

FORMATION AND LOCALITY.—Passage beds between the Cambrian
and the Ordovician: (310) Ceratopyge limestone (zone 4), at Ottenby, on
Oeland Island; and (309) Ceratopyge limestone (zone 4), at Fogelsdng, 5
miles (8 km.) east of Lund, Province of Malméhus; both [Moberg and
Segerberg, 1906, p. 66] in Sweden.

Cc

ACROTRETA CIRCULARIS Moberg and Segerberg.
FIGURE 56.—A crotreta carinata Moberg and Segerberg- :
A, Top view of ventral valve. B, Back view of Text figures 57A-C.
ventral valve. ©, Side view of ventral valve. D,

Dorsal-valve. AllX 8. @he ventralis the type Acrotreta circularis MopErG and SrcERBERG, 1906, Medd. fran Lunds

Geol. Faltklubb, Ser. B, No. 2 (Aftryck ur K. Fysiografiska Sall-

The specimens represented are from Locality 309,

the Ceratopyge limestone at Fogelsing, Province of skapets Handl., N. F., Bd. 17), pp. 65-66, Pl. III, figs. 4a-c. (De-
MalmGéhus, Sweden. The figures are copied from scribed in Swedish as a new species; see below for translation.
Moberg and Segerberg [1906, Pl. THI, figs. sa-e and 6}. The figures are reproduced in this monograph as figs. 57A-C.)

The original description by Moberg and Segerberg follows:

The apex of the larger shell (ventral valve) is situated midway between the posterior edge and the center, or possi-
bly (the apex itself is not preserved) somewhat closer to the center. On the posterior edge there is a slightly defined
triangular area which has a median rounded ridge extending out from the apex. The area as a whole is also somewhat
arched, not quite level; at the posterior edge it occupies about one-fifth of the entire circumference of the shell. The
height (from the apex to the level of the edge of the shell) is about two-thirds of the breadth. Shell smooth, shiny,
with fine concentric growth lines visible even on the area, where, however, they are feebler. On both sides of the
apex where the shell, as above mentioned, has been removed,
there is found a furrow which on the area is parallel with
its nearest side edge, and in the opposite direction runs

- obliquely toward the side. In the direction from the apex
down toward the anterior edge the shell is quite arched. The
species differs from Acrotreta socialis von Secebach, as known
from examples from the forchhammeri zone, by its greater size,

B

its distinct keeled area, and the more subcentral position of F!GURE 57.—Acrotreta cirewlaris Moberg and Segerberg. A, Top

view. B, Posterior view. C, Side view. Ali xX 8.
The specimen represented is from Locality 309, the Ceratopyge
Observations.—This shell is nearest to Acro- limestone at Fogelsing, Province of Malmohus, Sweden. The fig-

: a A ures are copied from Moberg and Segerberg[1906, Pl. III, figs. 4a-c].
treta seebachi (Pl. LX XVII, figs. 3,3a). It differs
in having the apex farther back from the posterior margin and in the strong median ridge on
the false area. Itis very close to Acrotreta carinata Moberg and Segerberg.

the apex, which again causes the arch to be less raised.

TFoRMATION AND LOCALITY.—Passage beds between the Cambrian and the Ordovician: (310) Ceratopyge lime-
stone (zone 4), at Ottenby, on Oeland Island; and (809) Ceratopyge limestone (zone 4), at Fogelsdéng, 5 miles (8 km.)
east of Lund, Province of Malméhus,; both [Moberg and Segerberg, 1906, p. 66] in Sweden. ‘

ACROTRETA CLAYTONI Walcott.

Plate LX XIV, figures 3, 3a-b.
Acrotreta claytoni Waucott, 1902, Proc. U. S. Nat. Mus., vol. 25, p. 583. (Described as below as a new species.)

The material representing this species does not give sufficient data for the preparation of a
detailed description. The only ventral valve is depressed by compression in the shale; it is
transversely broad oval in outline, with the posterior margin nearly straight for a distance of

ACROTRETIDA. 681

two-fifths of the diameter of the valve; the false area is fairly well defined by the abrupt incurv-
ing of the cardinal slopes; its median furrow is distinctly outlined, and it slopes forward to the
apex, which is situated about two-fifths the distance from the posterior margin to the front
margin. Pedicle aperture minute and directed upward from the extreme apex of the valve.
Dorsal valve gently convex. Surface of shell marked by fine concentric striz and lines of
growth, and very fine irregular, undulating striz that can be seen only by the aid of a strong lens.

A partial cast of a dorsal valve from the same faunal horizon about 30 miles distant shows
a well-defined median ridge and cardinal scars.

Observations.—This species is most nearly related to Acrotreta primeva Walcott of the
upper Olenellus fauna, at Pioche, Nevada. It differs in having a less elevated ventral valve
and in the more advanced position of the apex and foraminal aperture. All the specimens
known are also smaller than the average of A. primzva, the largest bemg 3 mm. in width and
2.5 mom. in length.

The specific name is derived from Clayton Valley, near the type locality.

FORMATION AND LOCALITY.—Lower Cambrian: (41) Limestone in the Pioche formation [Walcott, 1908a, p. 11]
on a ridge 2.5 miles (4 km.) northwest of the town of Cherry Creek, White Pine County, Nevada.

(175) Shales carrying Olenellus on the divide between Clayton and Fish Lake valleys, about 15 miles (24.2 km.) south-
southwest of Silver Peak; (184) shales at the summit of the Silver Peak Range, 10 miles (16.1 km.) southwest of the town
of Silver Peak; and (11) shales of No. 3 of the Silver Peak group, Barrel Spring section [Walcott, 1908f, p. 1894], 2.5

miles (4 km.) south of Barrel Spring and 0.5 mile (0.8 km.) east of the road, in the extreme southeastern corner of
the Silver Peak quadrangle; all in the Silver Peak quadrangle (U.S. Geol. Survey), Esmeralda County, Nevada.

ACROTRETA CONCENTRICA Walcott.
Plate LX XVII, figures 1, la—b.

Ca

Acrotreta concentrica Waucort, 1902, Proc. U. 8. Nat. Mus., vol. 25, p. 583. (Described as below as a new species.)

Shell small, outline subcircular to transversely broad oval; apex of ventral valve nearly
central; false area indicated by a slight flattening of the valve on the posterior side, and a
distinctly marked, but very narrow, median furrow. The elevation of the valve is about one-
half its diameter. The dorsal valve is slightly convex and its cast is marked by small cardinal
scars and a narrow median ridge that extends to the anterior third of the shell. A ventral
valve is 1.25 mm. in diameter, and one dorsal valve is 2 mm. in length.

Observations.—This species occurs at about the horizon of Acrotreta kutorgar Walcott but
is distinguished from that species and all others by the central position of the apex of the
ventral valve.

This form owes its specific name to the nearly central position of the apex of the ventral
valve.

FoRMATION AND LOCALITY.—Middle Cambrian: (96x) Limestone 1 mile (1.6 km.) north of Adairsville, 15 miles
(24.2 km.) northwest of Cartersville, Cartersville quadrangle (U. S. Geol. Survey), Bartow County, Georgia.

ACROTRETA CONULA Walcott.
Plate LX XV, figures 2, 2a—b.
Acrotreta conula Watcort, 1902, Proc. U. S. Nat. Mus., vol. 25, p. 584. (Described as below as a new species.)

Shell small. Ventral valve eccentrically cone-shaped, with a broadly oval transverse
aperture. The apex is situated at the posterior third of the distance between the front margin
and the posterior edge of the slightly indicated false area. A minute pedicle aperture occurs
at the summit of the apex. Dorsal valve convex, with the minute beak at the posterior margin.
The cast shows a well-defined median ridge with the central muscle scars well back on the
valve.

Surface marked by fine concentric striz and lines of growth.

This form owes its specific name to the fact that the ventral valve is markedly cone-shaped.

FORMATION AND LOCALITY.—Upper Cambrian: (310a) Shales of Olenus truncatus zone, Oeland Island, Sweden.

a The species mentioned occur at two slightly different localities (11 and 1v), none of the species being common to both localities.

682 CAMBRIAN BRACHIOPODA.

ACROTRETA CONVEXA Walcott.
Plate LXVI, figures 6, 6a-c.

Acrotreta convera WaAucott, 1902, Proc. U. S. Nat. Mus., vol. 25, p. 584. (Described essentially as below as a new
species. )

Shell small, subcircular, valves convex. Ventral valve most elevated at the low apex,
which is above the slightly transverse posterior margin. Dorsal valve somewhat less convex
than the ventral valve, with its greatest elevation at the posterior third; beak minute, mar-
ginal. Length and width of shell 1 mm. Shell substance very thin, but not proportionally
thinner hoa other large forms. Surface marked by fine concentric strize and lines of growth.

Casts of the interior of the ventral valve show a minute apical callosity and oardltnell scars.
The cast of the dorsal valve has a long median furrow and minute cardinal scars.

Observations.—This minute shell occurs in the shales and in a fine-grained interbedded
sandstone of the Upper Cambrian. It is characterized mainly by the convexity of the dorsal
valve and the relatively low ventral valve, characters that point to its descent from a form
like Acrotreta sagittalis.

The cast of a dorsal valve represented by Plate LXVI, figure 6c, shows a great develop-
ment of the cardinal muscle scars; this is abnormal or else the valve belongs to another species.

FORMATION AND LOCALITY.—Upper Cambrian: (8n) Thin-bedded sandstone on Salmon River, Gillis Hill, 13 miles
(20.9km.) south of Marion Bridge; (10e) shales on east branch of Barachois River, 0.5 mile (0.8 km.) north of the cross-
road from Boisdale to Upper Leitches Creek; (101) shale on east bank of Barachois River, 6 miles (9.6 km.) from Little
Bras d’Or Lake; and (10i) shale in high bank on west side of Barachois River, just north of the Boisdale road; all in
eastern Cape Breton, Nova Scotia, Canada.

ACROTRETA CURYATA Walcott.

Plate LX VIII, figures 1, la—n.

Acrotreta gemma Watcort (in part) [not Bruxines], 1884, Mon. U. 8. Geol. Survey, vol. 8, pp. 17-18, Pl. I, figs. 1d
and le (not figs. la, 1b, 1c, and 1f; see below). (Specimens now referred to Acrotreta attenuata, A. pywidicula,
and A. idahoensis alta were included with the specimens representing A. curvata when this description of
A. gemma was written, A. idahoensis alta being figured (Pl. I, figs. la and 1b). The specimens represented
by Pl. IX, figs. 9 and 9a, can not be positively located at this time, but it is probable that they should be
referred to A. idahoensis alta. The specimens represented by Pl. I, figs. 1d and le, are redrawn in this mono-
graph, Pl. LXVIII, figs. 1g and 11, respectively. Fig. 1c sepneveniadl a specimen of Acrotreta sabrine, and
the specimen represented by fig. 1f is missing.)

Acrotreta gemma Waucort (in part) [not Bruutnes], 1891, Tenth Ann. Rept. U. 8S. Geol: os p. 608, Pl. LX VII,
fig. 5b (not figs. 5, 5a, 5c, 5d, and 5e; see below). (Fig. 5b isa copy of Fig. 1d of preceding reference. Speci-
mens now referred to Acrotreta attenuata, A. pyxidicula, A. idahoensis alta, and A. primxva were included with
the specimens representing A. curvata in this reference to A. gemma, but only the last two were figured;
AN idahoensis alta, Pl. LX VII, figs. 5 and 5a, and A. primxva, Pl. LX VII, figs. 5c, 5d, and 5e.) .

Acrotreta gemma Hau ann CLARKE (@ part) [not Bizxines], 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1,
p. 102, fig. 55 (not figs. 56 and 57; see below). (Mentioned in the text and fig. 55 copied from Walcott, 1884b,
Pl. I, fig. ld. The specimens represented by figs. 56 and 57 are referred in this monograph to Acrotreta idaho-
ensis alta.)

Acrotreta gemma Waucort (in part) [not Brtmyes], 1899, Mon. U. S. Geol. Survey, vol. 32, pt. 2, p. 449, Pl. LXII,
fig. 2e (not figs. 2, 2a-d; see below). (Fig. 2e is a copy of Walcott, 1884b, Pl. I, fig. ld. Specimens now
referred to Acrotreta attenuata, A. pyxidicula, A. idahoensis alta, and A. primexva were included with the speci-
mens representing A. curvata when this description of A. gemma was written, but only the last two were figured:
A. idahoensis alta, Pl. LXII, figs. 2a and 2c, and A. primxva, Pl. LXII, figs. 2, 2b, and 2d.)

Acrotreta curvata Waxtcort, 1902, Proc. U. 8. Nat. Mus., vol. 25, p. 584. (Characterized essentially as below as a
new species.)

This is a clearly defined species and all that is known of it, with the exception of the very
fine concentric surface striz, can be illustrated. It belongs with Acrotreta idahoensis Walcott
and other species with a broad false area. It differs from described species in the incurved
apex of the ventral valve, the strong sinus of the dorsal valve, and the general aspect of the
two valves.

ACROTRETID. 683

This form owes its specific name to the fact that the apex of the-ventral valve is strongly
incurved.

FoRMATION AND LOCALITY.—Passage beds between the Upper Cambrian and the Ordovician: (203a) Lime-
stones at base of Pogonip limestone, in the spur on Hamburg Ridge extending out southwest from Wood Cone, Eureka dis-
trict [Hague, 1892, Atlas], Eureka County, Nevada.

Upper Cambrian: (12p) About 225 feet (69 m.) above the igneous rocks in the limestones of the Reagan sand-
stone, at the northwest extremity of the Arbuckle Mountains, about 4 miles (6.4 km.) east of Homer, Carter County,
Oklahoma.

AcCROTRETA pEFinirA Walcott.

Plate LXIV, figures 2, 2a-g, 3, 3a-b.

Acrotreta definita Waucort, 1902, Proc. U. S. Nat. Mus., vol. 25, pp. 584-585. (Described essentially as below as a
new species.) :

For exterior outline, form, and convexity of the valve, the student is referred to the
illustrations (Pl. LXIV). It is to be noted that the false pedicle groove is very distinct and
also broader than that of Acrotreta attenuata Meek. ‘The interior of the ventral valve is beau-
tifully shown by casts. One of these (fig. 2c) shows the strong vascular sinuses, cardinal scars,
cast of apical callosity, and, just in front of the latter, two slight tubercles, which may be the
cast of depressions corresponding to the foraminal pits of Acrothele. The cast of the dorsal
valve is also very instructive in showing the area, cardinal scars, median ridge, and central
sears.

Observations —This large fine species differs from its nearest ally, Acrotreta idahoensis
Walcott, in the false area and the details of the arrangement of the vascular markings and
muscle scars of the interior of the valves. The Idaho shells occur in a dark argillaceous shale
and were collected by R.S. Spence, of Evanston, Wyoming. The Eureka (Nevada) specimens
(Pl. LXIV, figs. 3, 3a—b) are from a shaly limestone.

Acrotreta depressa (Pl. LXVI, figs. 8, 8a—c) occurs at about the same stratigraphic horizon,
but it has, when uncompressed, a more elevated and sharper apex.

ForRMATION AND LOCALITY.—Middle Cambrian: (55) Shaly limestone at the top of the Eldorado limestone [Wal-
cott, 1908f, p. 184], east slope of Prospect Mountain, in New York Canyon, Eureka district [Hague, 1892, Atlas]; and
(57) shaly limestone of the Eldorado limestone [Walcott, 1908f, p. 184], at the 700-foot (213.4 m.) level of the Rich-
mond mine, Ruby Hill [Hague, 1892, p. 43, and Pl. I, opposite p. 116]; both in Eureka County, Nevada.

(55¢ and 163) Spence shale member of the Ute limestone [ Walcott, 1908a, p. 8], about 50 feet (15.2 m.) above the
Brigham quartzite and 2,755 feet (839.7 m.) below the Upper Cambrian, in a ravine running up into Danish Flat from Mill
Canyon, about 6 miles (9.6 km.) west-southwest of Liberty, and 15 miles (24.2 km.) west of Montpelier, Bear Lake County,
Idaho.

(40) Shale about 375 feet (115 m.) above the unconformable base of the Cambrian, in divide at the head of

Jackson Creek (locally known as Sheep Creek), a creek flowing into Jackson Lake about 0.5 mile (0.8 km.) south of
its northwestern corner, Teton Mountains, Grand Teton quadrangle (U. S. Geol. Survey), Uinta County, Wyoming.

ACROTRETA DEPRESSA (Walcott).
Plate LXVI, figures 8, Sa-c.

Acrotreta gemma depressa Waucort, 1889, Proc. U. 8. Nat. Mus. for 1888, vol. 11, pp. 441-442. (Reason given for
separation as a new variety.)

Linnarssonia sagittalis Waucorr, 1889, idem, p. 442. (Mentioned.)

Acrotreta gemma depressa Walcott, MartHew, 1902, Trans. Roy. Soc. Canada for 1902, 2d ser., vol. 8, sec. 4, No. 3,
p. 109. (Copies Walcott, 1889c, p. 441, and proposes the species A. depressa.)

Acrotreta depressa Waxcott, 1908, Canadian Alpine Journal, vol. 1, No. 2, p. 245, Pl. I, figs. 3, 3a-c. (No text refer-
ence. Figs. 3, 3a-c are copied in this monograph, Pl. LXVI, figs. 8c, 8c’, 8a, and 8, respectively.)

A group of depressed ventral valves in an arenaceous argillaceous shale led me [1889c,
p- 441] to distinguish the shell as a variety of Acrotreta gemma Billings. Material received
since 1889, from a black and finer shale, shows an elevated ventral valve much like that
of A. idahoensis alta Walcott, but at present I am unable to decide that the typical form of

@163 is the type locality.

684 CAMBRIAN BRACHIOPODA.

A. depressa (figs. 8 and 8’) is the same as the elevated ventral valve represented by figure 8c, or
that the latter is A. idahoensis alta; neither form should be referred to A. gemma. A. definita
(Pl. LXIV, figs. 2, 2a-g) occurs at the same relative stratigraphic horizon as this species and
it is about the same size. It differs in having a lower, less elevated, and less pointed apex
on the ventral valve.

This form owes its specific name to the fact that its ventral valve is depressed.

ForMATION AND LOCALITY.—Middle Cambrian: (14s) About 2,300 feet (701 m.) above the Lower Cambrian and
2,700 feet (823 m.) below the Upper Cambrian in the Ogygopsis zone of the Stephen formation [ Walcott, 1908f, p. 210], at
the great ‘‘fossil bed,’’ on the northwest slope of Mount Stephen, (574) about 2,200 feet (670.6 m.) above the Lower Cam-
brian and 2,800 feet (853.4 m.) below the Upper Cambrian in the limestone forming 1 of the Stephen formation
[Walcott, 1908f, p. 209], about 0.5 mile (0.8 km.) east of the great ‘‘fossil bed” on Mount Stephen; (58j) about 1,900 feet
(579 m.) above the Lower Cambrian and 3,100 feet (945 m.) below the Upper Cambrian, near the base of the lime-.
stone forming 2 of the Stephen formation [Walcott, 1908c, p. 238(7)], on the east side of Mount Stephen about 3,000
feet (914 m.) above the Canadian Pacific Railway track; and (58r) about 1,800 feet (548.6 m.) above the Lower Cambrian.
and 3,200 feet (975.4 m.) below the Upper Cambrian, in the limestones forming 2 of the Stephen formation [Walcott,
1908f, p. 211], in the amphitheater between Mounts Stephen and Dennis; all near Field on the Canadian Pacific
Railway, British Columbia, Canada.

ACROTRETA EGGEGRUNDENSIS Wiman.
Plate LXX, figures 2a-d.

Acrotreta eggegrundensis WimaAN, 1902, Bull. Geol. Inst. Univ. Upsala, vol. 6, pt. 1, No. 11, p. 55, Pl. II, figs. 23-29.
(Described in German as a new species. The two specimens represented by figs. 29, 27, and 26, and fig. 24 are
redrawn in this monograph, Pl. LX X, figs. 2a-c and 2d, respectively.)

Acrotreta eggegrundensis Wiman, Watcott, 1905, Proc. U. S. Nat. Mus., vol. 28, pp. 299-300. (Characterized as
below.)

This species is of a characteristic Middle Cambrian type of Acrotreta represented in America
by A. idahoensis Walcott and A. kutorgat Walcott. The surface is marked by unusually strong
lines and ridges of growth and the false area is well defined. It is quite distinct from other
species of the genus in Huropean formations.

Carl Wiman [1902, p. 51] refers this species to the Olenellus sandstone series. The bowlder
containing it also carried Aparchites? andersson, Hipponicharion matthewi, Obolus ( Westonia)
bottnicus, Kutorgina?, Torellella levigata, and fragments referred to Olenellus. his fauna is
essentially Middle Cambrian in its facies, and unless the fragments referred to Olenellus are
indisputably of that genus, I am inclined to refer the bowlder and its contained fossils to the
Middle Cambrian. The fact that Obolus ( Westonia) bottnicus is nearly identical with O. ( W.)
jinlandensis of the Middle Cambrian of Finland also points to the Middle Cambrian age of
the fauna.

The specific name is derived from Eggegrund Island, the type locality.

ForMATION AND LOCALITY.—Middle? Cambrian: (311) Drift bowlder of coarse-grained, somewhat friable, glauconitic
sandstone, No. 3 |Wiman, 1902, p. 57], on Eggegrund Island, about 25 miles (40 km.) northeast of Gefle, Province of
Gefleborg; and (811a) drift bowlder of glauconitic sandstone [Wiman, 1902, p. 57], at Norrskedika, a little northwest
of Osthammar, Province of Stockholm; both in Sweden. h

(311d) Drift bowlder of glauconitic sandstone [Wiman, 1902, p. 57], south of Lumparstroémmen, Aland Island,
Finland, Russia.

ACROTRETA EMMONSI Walcott.
Plate LXV, figure 6.

Acrotreta emmonst WaxcotT, 1905, Proc. U. 8. Nat. Mus., vol. 28, p. 300. (Characterized as below as a new species.)

Only the interiors of the two valves of this species are known. The one illustrated shows
the distinct character of the vascular markings and muscle scars. The only shell with which
it can be compared is the dorsal valve of Acrotreta idahoensis Walcott (Pl. LXV, figs. 1f, 1g).
This shell resembles Obolella, but its corneous test, cardinal muscle scars, and absence of area
of the Obolella type prevent a reference to that genus. Fragments of Olenellus occur in the
layer of limestone from which the specimens were obtained.

ACROTRETID. 685

The specific name is given in memory of Dr. Ebenezer Emmons, who studied and wrote
of the Bald Mountain section.

FoRMATION AND LOcALITY.—Lower Cambrian: (35a) Shaly limestone on the west slope of the summit of Bald Moun-
tain, 3 miles (4.8 km.) north-northwest of Greenwich, Schuylerville quadrangle (U. S. Geol. Survey); and (38a) limestone
2 miles (3.2 km.) south of North Granville, on the road which turns south from the road running between that village
and Truthville, 4 miles (6.4 km.) west-northwest of Granville, Fort Ann quadrangle (U. S. Geol. Survey); both in
Washington County, New York.

ACROTRETA GEMMA Billings.

Plate LXVI, figures 1, la—b.

Acrotreta gemma Bitines, 1865, Geol. Survey Canada, Paleozoic Fossils, vol. 1, pp. 216-217, figs. 20la-f. (Described
as below as.a new species. The specimens represented by figs. 201b, d, e, and f are redrawn in this monograph,
Pl. LXVI, figs. 1, la—b, respectively.)

Not Acrotreta gemma Waxcort [1884b, p. 17; 1886b, p. 98; 1891a, p. 608; or 1899, p. 449]. (The specimens referred to
Acrotreta gemma Billings in the references mentioned have been referred in this monograph to Acrotreta attenuata,
A. curvata, A. idahoensis alia, A. primxva, and A. pyxidicula, which see.)

The original description by Billings follows:

Shell very small, about 1 line in diameter; one valve nearly flat and the other acutely conical. Dorsal valve
very gently convex, nearly circular; sides and front margin uniformly rounded; posterior margin very obtusely angu-
lated at the beak, on each side of which a portion of the cardinal edge, equal to one-fourth of the whole width of the
shell, is nearly straight; umbo very small; beak apparently depressed to the hinge line and not projecting beyond it;
cardinal angles compressed, broadly rounded; a wide, shallow, mesial sinus extends from the front margin about half-
way to the beak; elsewhere the valve is gently convex or nearly flat.

Ventral valve acutely conical, with a flat triangular area which is perpendicular to the plane of the lateral margin,
its base half the width of the whole shell. In the apex of this valve there is a minute circular aperture, and in one
specimen a dark line extends from it down the middle of the area, which appears to represent the foraminal groove
of this genus; but in two other specimens of the ventral valve, with the area well preserved, there is no indication of
a groove. Surface with very fine concentric striz.

Width of dorsal valve about 1 line; length about eight-ninths ofa line. The height of the ventral valve is about
1 line.

The form of this species is very like that of A. swbconica Kutorga, but that species is twice the size of this and has
the area distinctly grooved.

Observations.—By the courtesy of Prof. J. F. Whiteaves, of thé Geological Survey of
Canada, I have had the opportunity of studying the type material of this species. Nine speci-
mens of the ventral valve were received, but none of the dorsal valve, as they could not be
found. One specimen in a dove-colored limestone appears to belong to a distinct species,
which I have named Acrotreta ovalis. The remaining specimens show some variation in the
angle of slope of the sides of the ventral valve, but four of them are similar to the form illus-
trated by Billings [1865a, p. 216].

The broad false area, with a scarcely perceptible impression of the path of advance of
the pseudodeltidium, is clearly shown in one of the specimens, and faintly in others. Two
shells have the apex broken off so as to expose the cast of a minute apical callosity and a small
portion of the side of the cast of the main vascular sinus (Pl. LXVI, fig. 1b).

Acrotreta gemma belongs to the A. subconica Kutorga group of the genus, having a high
ventral valve and a distinct and broad false area. It differs from A. subconica in having a less
elevated ventral valve and in the apex being in front of the posterior margin instead of extending
over it. <Acrotreta gemma has no strong specific relations with the forms from the Rocky
Mountains that I identified with it. A. attenuata Meek has a high ventral valve, but the false
area is practically absent, a narrow, deep sulcus taking its place. A. idahoensis alta Walcott
has the elevation and false area, but differs in the details of the area and the outline of the cross
section of the ventral valve. It was this form that led mé [1884b, p. 17] to consider that A. gemma
occurred in Nevada, and with the slight knowledge that I then had of the genus and species a
wide variation of form was given to A. gemma. As far as now known to me, the species is
restricted to the type locality.

FORMATION AND LOCALITY.—Lower Ordovician: (314d [Billings, 1865a, p. 217]) Limestone of Division P of the
“‘Quebec group,’”’ 4 miles (6.4 km.) northeast of Portland Creek, Newfoundland.

686 CAMBRIAN BRACHIOPODA.

ACROTRETA GEMMULA Matthew.
Plate LXYVI, figures 3, 3a-c; Plate LX XVII, figures 5, 5a-f.

Acrotreta gemmula MarraEw, 1894, Trans. Roy. Soc. Canada for 1893, Ist ser., vol. 11, sec. 4, No. 8, pp. 87-88, Pl. XVI,
figs. 2a-d. (Described as a new species. The specimens represented by figs. 2a and 2b are redrawn in this
monograph, Pl. LXVI, figs. 3a and 3b-c, respectively.)

Acrotreta gemmula Marrusw, 1895, Trans. New York Acad. Sci. for 1894-5, vol. 14, p. 126, Pl. V, figs. da-d. (Changes
stratigraphic range. Copies figures from preceding reference. )

Acrotreta gemmula Marrunw, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, p. 97, Pl. III, figs.
4a-d. (Mentioned. Figures copied from Matthew, 1894, Pl. XVI, figs. 2c, 2d, 2a, and 2b, respectively.)
Shell small, nearly circular in outline, with the posterior margin slightly straightened.

Height of ventral valve above the posterior margin about one-half the length of the valve.

Apex slightly incurved over the false area, which varies from nearly vertical to an appreciable

forward slope from the margin. False area with rounded lateral margins and a rather strong

median groove that terminates in a sulcus at the margin and begins at a minute foraminal
aperture just beneath the apex. The position of the pedicle aperture causes it to open almost
directly backward. The dorsal valve is moderately and rather uniformly convex. Surface
of shell marked by fine, concentric strie and lines of growth, and toward the outer margin
by very fine, undulating, concentric strie that give the surface, when examined by a strong
lens, the fretted appearance shown on a larger. scale on Obolus ( Westonia) ella (Hall and Whit-
field) and a few species of Acrotreta. The size of the shell is about that of Acrotreta convexa

Walcott, 1.5 to 2mm. in diameter. The shell appears to have been rather thin, as it is indented

by the pressure of the fine grains of sand of the matrix, and often bends rather than breaks when

compressed. It is built up of very thin layers or lamelle that in the dorsal valve form a

thickened rim.

The cast of the interior of the ventral valve indicates a small but distinctly marked apical
callosity penetrated by a rather strong pedicle tube that is directed backward at an angle of
about 45°. A trace of the main vascular sinuses is shown at the anterolateral edges of the
apical callosity; the casts of the cardinal scars are rather large for so small a shell. The interior
of the dorsal valve is marked by a rather strong median ridge, large cardinal scars, and small
central scars. One of the strongly marked characters is the strong outer rim.

This is a very clearly defined species and the oldest of the Acadian representatives of the
genus, occurring, as it does, just below the “ Protolenus fauna.”” The position of the pedicle
aperture is similar to that of many species of Acrothele and is unusual for the genus, and may
be of generic or subgeneric importance.

In the collections made by Loper on Dugald Brook this species occurs with Obolus (Palzobolus)
bretonensis (Matthew) in beds beneath Acrothyra proavia (Matthew). He collected a fine series of
this species at the same horizon from which Matthew obtained the types of his “‘Acrotreta paptllata”’
(see Acrothyra sera (Matthew), p. 718). I find that when the outer surface of the shell is well
preserved it has a slightly fretted or pitted appearance on specimens from Hanford Brook and
also Dugald Brook. Those from Dugald Brook show radiating lines when the thin outer layer
of the shell is exfoliated. In some layers of rock all the shells are finely pitted, evidently by
the fine grains of quartz sand in the matrix being pressed against the shell; in other layers the
shells are identical in surface markings and form with those of A. gemmula from Hanford
Brook.

The interiors of the dorsal valve are not sufficiently well preserved for comparison, but in
the ventral valve they are essentially the same. In each locality there is considerable variation
in the form and size of the apical callosity.

FORMATION AND LOCALITY.—Middle Cambrian: (301a [ Matthew, 1894, p. 88]) Fine-grained sandstones below the
Protolenus-bearing shales and sandstones in Division 163 of Matthew on Hanford Brook; and (301 [Matthew, 1895a,
p. 126]) sandstones of Division 1b2 of the “‘Protolenus zone” of Matthew on Hanford Brook; both in St. John County,
New Brunswick.

(10p) Sandstone just below the waterfall in Division E2b of Matthew’s [1903, p. 21] Etcheminian, Dugald

Brook, Indian River; and (10p’”) sandstone on the small brook on the hill between the bridge over Indian River and
McPhees Brook; both in eastern Cape Breton, Nova Scotia, Canada.

ACROTRETID. 687

ACROTRETA GRACIA Walcott
Plate LX VI, figures 5, 5a—-d.

Acrotreta gracia Watcort, 1902, Proc. U. S. Nat. Mus., vol. 25, pp. 586-587. (Described and discussed essentially
as below as a new species.)

Shell small, slightly transverse; apex of ventral valve about one-third the length of the
shell from the posterior margin; height about two-thirds the leneth of the shell; false area
defined by the sharp rounding of the cardinal slopes and the transverse posterior margin, which
is indented by the strong, broad, median groove extending from the margin to the apex, where
it almost comes in contact with the minute apical pedicle opening. Dorsal valve moderately
convex with a nearly straight or gently curved posterior margin; beak minute, marginal. Sur-
face of shell marked by fine concentric striz and lines of growth. Shell strong and built up
of thin layers or lamellz that over the central and anterior portions are more or less oblique
to the outer surface layer.

The cast of the ventral valve indicates a small but very clearly marked apical callosity;
rather small cardinal scars and main vascular smuses. The false area is narrow and broken
midway by a rather wide, slightly arching false deltidium. The cast of the interior of the
dorsal valve shows a broad, low, median ridge extending to about the anterior third of the
length of the valve, large cardinal muscle scars, and small main vascular sinuses that arch
inward after passing the central scars, and then outward.

Observations.—This species is distinguished by the strong shell, broad median ridge of
the dorsal valve, and deep median groove of the false area of the ventral valve. The light
color of the shell may be owing to the character of the limestone in which it is preserved, or
it may be that it is a little more calcareous than other species of the genus.

The Acrotreta which Matthew [1897b, p. 169] describes and illustrates from the Hastings
Cove locality (“Linnarssonia belti magna’) is characterized by a narrow median ridge in the
dorsal valve and other characters not present in A. gracia. In the Paradozides zone on Han-
ford Brook I found numerous examples of a species of Acrotreta that appears to be identical
with the form described by Matthew [1897b, p. 169] and have referred it as a variety (magna)
of Acrotreta sagittalis (Salter) (p. 706).

ForRMATION AND LOCALITY.—Middle Cambrian: (2s) Limestone in upper part of Paradoxides zone, Hastings

Cove [Matthew, 1898b, p. 38], on Kennebecasis Bay, 0.5 mile (0.8 km.) northeast of Torryburn, on the Intercolonial
Railway, northeast of St. John, St. John County, New Brunswick.

ACROTRETA IDAHOENSIS Walcott.
Me

Plate LXV, figures 1, lai; Plate LX VIII, figures 2, 2a-c.

Acrotreta attenuata MrEx (in part), 1873, Sixth Ann. Rept. U. S. Geol. and Geog. Survey Terr. for 1872, p. 463, foot-
note. (Among the specimens which Meek listed as A. subconica and for which he proposed the name A. attenuata
in a footnote are specimens which are now referred to A. idahoensis. See also A. attenuata and A. attenuata var.)

Not Acrotreta subconica Kutore@a, 1848, Verhandl. Russ.-kais. min. Gesell. St. Petersburg for 1847, No. 12, p. 275.
(Referred in this monograph to Acrotreta subconica.)

Acrotreta idahoensis Waucortt, 1902, Proc. U. S. Nat. Mus., vol. 25, p. 587. (Described essentially as below as a new
species. )

The general outline, form, and convexity of the two valves are so fully shown by the illus-
trations that detailed descriptions will not be given. The material for illustrating the interior
of the ventral valve is limited, but one cast shows the position of the base of the cast of the
foraminal tube, and the large, main vascular sinuses (Pl. LXV, fig. 1d). An interior of a dorsal
valve and the accompanying cast (Pl. LXV, figs. 1f, 1g) present characters rarely seen in this
genus. The vascular canals arch out beyond the central muscle scars, and then bend in toward
the median ridge, and again obliquely outward to form the outer limit of a smooth, polished,
lanceolate-shaped surface that extends obliquely outward from the median ridge. The line
that extends from in front of the cardinal scars forward, subparallel to the margin of the shell,
and then bends abruptly in and forward is apparently the outer boundary of a very broad,

688 CAMBRIAN BRACHIOPODA.

shallow, vascular sinus. Something of this same character occurs in the dorsal valve of
Obolus (Lingulobolus) spissus (Billings) (Pl. XVI, figs. 2, 2d). The cardinal scars are small
and situated close to the narrow area. Another cast of the mterior (fig. le) shows the central -
sears distinctly; also the presence of a thickening of the shell in the vicinity of the cardinal
scars. The median ridge is smaller and shorter than in Plate LXV, figure 1g.
Observations.—The external characters of this species suggest Acrotreta curvata Walcott,
but the elevation and curvature of the ventral valve are not the same and the interior of the
dorsal valve is very distinct in its specific characters. There are no interiors of the form from
the Black Hills, but the external characters appear to be the same. These include the broad
false area, with its slightly marked groove, the position of the apex, and the curvature of the

false area.

Acrotreta idahoensis has been found in the Dunderberg shale of the Eureka district, Nevada,
and it extends up also to the base of the Pogonip limestone. The horizon is higher than that
of the type specimen, but the shells from the higher and lower horizons appear to be identical.

ForMATION AND LOCALITY.—Lower Ordovician: (201a) Pogonip limestone, east slope of the ridge east of Ham-
burg Ridge; and (202) Pogonip limestone on the summit of the ridge directly southeast of the Jackson mine, north-
west of Shadow Canyon; both in the Eureka district [Hague, 1892, Atlas], Eureka County, Nevada.

Upper Cambrian: (61) Limestone in the Dunderberg shale [Walcott, 1908f, p. 184], a little south of the Hamburg
mine, Eureka district [Hague, 1892, Atlas], Eureka County; and (318) limestone 0.75 mile (1.2 km.) east-northeast of
McGill post office, White Pine County; both in Nevada.

(15d) Thin-bedded blue limestone near Cave Spring, on the east side of the Fish Spring Range, about 4 miles
' (6.4 km.) south of the J. J. Thomas ranch, Juab County; and (30h) about 350 feet (106.7 m.) above the Middle Cam-
brian and 2,950 feet (899.2 m.) below the top of the Upper Cambrian, near the base of the arenaceous limestones form-
ing 2a of the Orr formation [Walcott, 1908f, p. 177], on Orr Ridge, about 5 miles (8 km.) south of Marjum Pass, House
Range [Walcott, 1908, Pl. XIII], Millard County; both in Utah.

(5c and 54t) Limestones of the St.Charles formation | Walcott, 1908a, p. 6], about 250 feet (76 m.) above the Middle
Cambrian; and (54u) limestones of the St. Charles formation about 100 feet (30.2 m.) above the Middle Cambrian;
both on the north side of Twomile Canyon near its mouth, 2 miles (3.2 km.) southeast of Malade, Oneida County,
Idaho.

(56g) Limestone of the St. Charles formation [Walcott, 1908a, p. 6], in the valley of the stream which flows into
Mill Canyon from the west, about 6 miles (9.6 km.) west-southwest of Liberty and 15 miles (24.2 km.) west of Mont-
pelier, Bear Lake County, Idaho.

Middle Cambrian: (88a) Limestone about 100 feet (30.5 m.) above the quartzitic sandstone at the base of the
Cambrian, in the northern suburbs of Deadwood; and (165) limestone on the east side of the valley, in railroad cut
about 1 mile (1.6 km.) below the main part of Deadwood; both in the Black Hills, South Dakota.

(302a) Limestones at several places on the south side of the Gallatin Valley, Gallatin County, Montana. _

(302b) Limestones near Crowfoot Ridge, Gallatin quadrangle (U. S. Geol. Survey), Yellowstone National Park,
Wyoming. :

_ (59g) Limestones immediately overlying the Spence shale member of the Ute limestone [Walcott, 1908a, p. 8],
in a saddle north of the creek which flows into Mill Canyon from the west, about 5 miles (8 km.) west-southwest of
Liberty and 15 miles (24.2 km.) west of Liberty, Bear Lake County, Idaho. :

(110) About 2,750 feet (838.2 m.) above the Lower Cambrian and 1,650 feet (502.9 m.) below the Upper Cam-
brian, at the base of la of the Marjum limestone [Walcott, 1908f, p. 179], about 4 miles (6.4 km.) southeast of Antelope
Springs, in the spurat the junction of the Deseret and Swasey Spring roads [Walcott, 1908f, Pl. XIII], House
Range, Millard County, Utah.

ACROTRETA cf. IDAHOENSIS.

This species is represented by a single specimen of a somewhat imperfect ventral valve.
It is larger than the average shells of Acrotreta idahoensis Walcott, and appears to have had a
more incurved apex. The exterior layer is also duller and less distinctly striated than most
specimens of the latter species. The shell is built up of numerous thin layers or lamellz, more
or less oblique to the outer surface; the lamelle are marked by numerous fine radiating striz
and a few concentric strie. The general impression given by the shell is that it is an old shell
which has thickened by growth and become more robust and incurved than is usual in the
species with which it is compared.

FORMATION AND LOCALITY.—Middle Cambrian: (7j) Limestones at the north end of the Quinn Canyun Range, 1
mile (1.6 km.) northwest of the Italian Ranch foothills, Nye County, Nevada.

ACROTRETID.®. 689
ACROTRETA IDAHOENSIS ALTA Walcott.

Plate LXV, figures 4, 4a—b.

/ Aacrotreta gemma Waxcort (in part) [not Brzrnas], 1884, Mon. U. S. Geol. Survey, vol. 8, pp. 17-18, Pl. I, figs. la
and 1b (not figs. lef; see below), and (?) Pl. IX, figs. 9 and 9a (see also below). (Specimens now referred
to Acrotreta attenuata, A. pyxidicula, and A. curvata were included with the specimens representing A. idahoensis
alta when this description of A. gemma was written, A. curvata being figured, Pl. I, figs. 1d and le. The
specimen represented by Pl. I, fig. la, is redrawn in this monograph, Pl. LXV, fig. 4a. Fig. le represented
a specimen of Acrotreta sabrinz; the specimens represented by figs. 1f and 9 and 9a are missing.)

/ Acrotreta gemma Waxcortt (in part) [not Brnumes], 1891, Tenth Ann. Rept. U. S. Geol. Survey, p. 608, Pl. LX VII,
figs. 5 and 5a (not figs. 5b-e; see below). (Figs. 5 and 5a are copied from figs. la and 1b of preceding reference.
Specimens now referred to Acrotreta attenuata, A. pyxidicula, A. curvata, and A. primxva were included with
the specimens representing A. idahoensis alta in this reference to A. gemma, but only the last two were figured:

: A. curvata, Pl. LXVII, fig. 5b, and A. primxva, Pl. LXVII, figs. 5c, 5d, and 5e.)

\/ Acrotreta gemma Walcott, Hat and Crarxe (in part) [not Bmies], 1892, Nat. Hist. New York, Paleontology, vol.
8, pt. 1, p. 102, figs. 56 and 57 (not fig. 55). (Mentioned in the text, and figures copied from Walcott, 1884b,
Pl. I, Ags. la and 1b. The specimen represented by fig. 55 is referred in this monograph to Acrotreta curvata.)

Acrotreta gemma Watcort (in part) [not Brutres], 1899, Mon. U. S. Geol. Survey, vol. 32, pt. 2, p. 449, Pl. LXII,
figs. 2a and 2c (not figs. 2, 2b, 2d, and 2e; see below). (Figs. 2a and 2c are copied from Walcott, 1884b, Pl. I,
figs. la and 1b, asraeainivaliy. Specimens now referred to Acrotreta attenuata, A. pyxidicula, A. curvata, and A.
primezva were included with the specimens representing A. idahoensis alia when this description of A. gemma
was written, but only the last two were figured: A. curvata, Pl. LXII, figs. 2e, and A. primxva, Pl. LXII, figs.
2, 2b, and 2d.)

Acrotreta idahoensis alta Waucort, 1902, Proc. U. S. Nat. Mus., vol. 25, p. 588. (Cremoienincd essentially as below
‘as a new variety.)

This is one of the forms that I included with Acrotreta gemma Billings in the report on
the Paleontology of the Eureka district, Nevada [1884b, p. 17].- It has the broad false area
of A. idahoensis Walcott, but the ventral valve is more elevated\and the apex does not over-
hang the false area. From A. attenuata Meek it differs in having a broad false area.

A form indistinguishable from Acrotreta idahoensis alta occurs in the Dunderberg shale of
the Eureka district section of Nevada. The horizon is higher than that of the type specimen,
but there appears to be no way of distinguishing between the type and the Dunderberg shale
specimens.

A similar but smaller form extends up through from the Dunderberg shale into the
arenaceous and calcareous shales at the base of the Pogonip limestone, where fossils of the
Ordovician fauna occur. ‘

This form owes its varietal name to its high ventral valve.

FORMATION AND LOCALITY.—Lower Ordovician: (63) At base of Pogonip limestone, northeast of Adams Hill,
Eureka district [Hague, 1892, Atlas], Eureka County, Nevada.

Passage beds between the Upper Cambrian and the Ordovician: (201) Arenaceous Pogonip limestone on east
slope of ridge east of Hamburg Ridge; and (206a) sandy limestone on Hoosac Mountain; both in the Eureka district
[Hague, 1892, Atlas], Eureka County, Nevada.

Upper Cambrian: (61) Limestone in the Dunderberg shale [Walcott, 1908f, p. 184], a little south of the Hamburg
mine; and (65) limestone on the east side of Sierra Canyon, opposite Pinnacle Peak; both in the Hureka district [Hague,
1892, Oiee Eureka County, Nevada.

(54£) 150 feet (45.7 m.) above the Middle Cambrian and 1,075 feet (327.7 m.) below the top of the Upper Cambrian
in light-gray sandstone forming No. 4 of the St. Charles formation [Walcott, 1908f, p. 193], in Blacksmith Fork Canyon
about 10 miles (16.1 km.) east of Hyrum, Cache County; (84q) shales ahout 3,800 feet (1,158.2 m.) above the Brigham
quartzite [Walcott, 1908a, p. 8], in Wasatch Canyon, east of Lakeview ranch, about 5 miles (8 km.) north of Brigham,
Boxelder County; and (15d) thim-bedded blue limestone near Cave Spring on the east side of the Fish Spring nope

‘about 4 miles (6.4 km.) south of the J. J. Thomas ranch, Juab County; all in Utah.

Middle? Cambrian: (33n) Limestone pebbles, west front of the Payant Mountains, at the mouth of Crow Gree
about 4 miles (6.4 km.) east of Fillmore, Millard County, Utah. @

Middle Cambrian: (58) Shaly limestone in upper beds of Secret Canyon shale; east side of New York and Secret can-
yons, Eureka district [Hague, 1892, Atlas], Hureka County, Nevada.

(7i) Limestone just west of the summit on the road east of Schellbourne; and (313) limestones 3 miles (4.8 km.)
north-northeast of Schellbourne; both in the Schell Creek Range, White pine County, Nevada.

(302w) Limestone at Madison Mountain, Montana. &.

62667°—vou 51, pr 1—12——44 f

690 CAMBRIAN BRACHIOPODA.

ACROTRETA IDAHOENSIS SULCATA Walcott.
Plate LXV, figure 5.

Acrotreta idahoensis sulcata Waucortr, 1902, Proc. U. S. Nat. Mus., vol. 25, p. 588. (Characterized as below as a new
variety.)

This strongly marked ventral valve is associated with the variety alta, but in its rounded
posterior side and strong median groove it is quite distinct. The apex is broken off so as to
show the cast of a small apical callosity and the base of a minute foraminal tube.

This. form owes its varietal name to the fact that it possesses a suleate ventral valve.

FORMATION AND LOCALITY.—Upper Cambrian: (30h) About 350 feet (106.7 m.) above the Middle Cambrian and
2,950 (899.2 m.) below the top of the Upper Cambrian, near the base of the arenaceous limestones forming 2a of the
Orr formation [Walcott, 1908f, p. 177], on Orr Ridge, about 5 miles (8 km.) south of Marjum Pass, House Range [Wal-
cott, 1908f, Pl. XIII], Millard County, Utah.

(54t) Limestone of the St. Charles formation [Walcott, 1908a, p. 6], about 250 feet (76 m.) above the Middle Cam-
brian, on the north side of Twomile Canyon, near its mouth, 2 miles (3.2 km.) southeast of Malade, Oneida County,
Idaho.

Middle Cambrian: (54s) Dark blue-gray Langston limestone [Walcott, 1908f, p. 198], just above the Cambrian
quartzitic sandstones, north side of Twomile Canyon, near its mouth, 2 miles (3.2 km.) southeast of Malade, Oneida
County; (55¢) Spence shale member of the Ute limestone [Walcott, 1908a, p. 8], about 50 feet (15.2 m.) above the Brigham
quartzite and 2,755 feet (839.7 m.) below the Upper Cambrian, in a ravine running up into Danish Flat from Mill
Canyon, about 6 miles (9.6 km.) west-southwest of Liberty and 15 miles (24.2 km.) west of Montpelier, Bear Lake
County; and (322a) Langston limestone near Paris, Bear Lake County; all in Idaho.

ACROTRETA INCHOANS (Barrande).
Plate XV, figures 7, 7a.

Lingula inchoans BARRANDE, 1868, Faune silurienne des environs de Hof, en Baviére, p. 102, figs. 74 and 75. (De-
scribed in French as a new species; see below for translation. Figs.74 and 75 are reproduced in this mono-
graph, Pl. XV, figs. 7 and 7a, respectively.)

Lingula inchoans BARRANDE, 1868, Neues Jahrb. fiir Mineralogie for 1868, p. 692, unnumbered plate, figs. 74 and 75.
(Copy of preceding reference.)

Acrothele inchoans (Barrande), Pomprcxs, 1896, Tremadoc Fossilien bei Hof, p. 3. (Discussed in German.)

Acrothele inchoans (Barrande), Marruw, 1902, Bull. Nat. Hist. Soc. New Brunswick, vol. 4, pt. 5, No. 20, p. 404.
(Mentioned.)

Acrothele inchoans (Barrande), MartHEw, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, p. 103.
(Copy of preceding reference.)

The original description by Barrande follows:

Under this name we unite several very small shells, rounded in appearance, but more or less elongated, which,
however, might represent merely the youthful form of another species. These very flat shells show one or two con-
centric grooves at the external contour. The one which is represented in figure 74 [Pl]. XV, fig. 7, of this work]
has, moreover, in the middle a faint longitudinal groove which extends nearly throughout its length.

Dimensions: Length, 2mm.; breadth, 3.2 mm. on the specimen in figure 74 [Pl. XV, fig. 7, of this work].

Observations.—Pompeckj wrote me that he had concluded that this species was an Acrotreta
and not a Lingula. The illustrations and descriptions of Barrande suggest that the eae
represent the compressed dorsal valves of Acrotreta.

Matthew [1902a, p. 404] places this species under Acrothele, but with only the figure given
by Barrande I prefer to accept Pompeckj’s provisional wearenes to Acrotreta.

ForRMATION AND LOCALITY.—Passage beds between the Upper Cambrian and the Ordovician: (308¢ [Barrande,

1868a, p. 102]) Dark argillaceous shale in the suburbs of Hof; and (303i [Pompeckj, 1896a, pp. 7 and 8]) railway cut near
Schellenberg, a little distance back of the railway station at Neuhof, near Hof; both in Bavaria, Germany.

ne ACROTRETA INFLATA (Matthew).

Plate LX XVI, figures 1, la—k, 2, 2a.

Lingulella? inflata MattHEw, 1886, Trans. Roy. Soc. Canada for 1885, Ist ser., vol. 3, sec. 4, No. 4, p. 33, Pl. V, figs.
7 and 7a. (Discussed as a new species. The specimen represented by figs. 7 and 7a is redrawn in this mono-
graph, Pl. LX XVI, fig. 2.)

Lingulella? inflata MattHEew, 1895, Trans. New York Acad. Sci. for 1894-95, vol. 14, p. 127, Pl. V, figs. 3a—b. (Men-
tioned. Figures copied from preceding reference.)

ACROTRETIDE. | 691

DLingulella? inflata ovalis MarrHEw, 1895, Trans. New York Acad. Sci. for 1894-95, vol. 14, p. 127, Pl. V, figs. 4a—c.
(Described and discussed as a new variety. The specimen represented by figs. 4a—c is redrawn in this mono-
graph, Pl. LX XVI, fig. 2a.)

Lingulella? inflata MattHEW, 1898, Trans. Roy. Soc. Canada for 1898, 2d ser., vol. 4, sec. 4, No. 2, p. 128. (Mentioned.)

Acrothyra? inflata MartHEw, 1901, Bull. Nat. Hist. Soc. New Brunswick, vol. 4, pt. 4, No. 19, p. 304. (Merely suggests
change in generic reference.)

Lingulella (Acrothyra?) inflata MatrHEw, 1902, idem, vol. 4, pt. 5, No. 20, p. 390. (Mentioned.)

Acrotreta inflata (Matthew), Waucorr, 1902, Proc. U. 8. Nat. Mus., vol. 25, pp. 588-589. (Described essentially as
below. ) ;

Shell subcircular to transversely broad oval. Ventral valve subconical, with the apex
directed backward and usually on a line with the posterior margin, or extending beyond it
(Pl. LX XVI, figs. 1’ and 1a’), but it may be anterior to it (Pl. LX XVI, figs. 1b’ and 1d’);
false area slightly defined by the abrupt curvature of the cardinal slopes, median line depressed,
narrow, the two sides of the false area incurving to form it (Pl. LXXVI, fig. 1g); pedicle
aperture longitudinally oval and slightly truncating the apex. Dorsal valve gently convex,
with a minute marginal beak. Surface of shell marked by concentric strie and growth lines,
and fine, irregular, wavy strize that inosculate more or less, giving the surface a fretted appear-
ance under a strong lens. The inner surface is marked by concentric lines and rather strong
radiating lines. The shell is built up of a thin outer ornamented surface and several thin
inner layers or lamellz. The average length of the ventral valve is 4 mm. and the width 3 to
3.5mm. The dorsal valves are usually wider than long. Casts of the interior of the ventral
valve show strong cardinal scars, a strong apical callosity, and rather weakly developed main
vascular sinuses. The apical callosity varies in size and in form from elongate oval (Pl. LX XVI,
fie. 1b) to subcircular (fig. 1f). The cast of the interior of the dorsal valve shows large cardinal
muscle scars, and a broad, short median ridge posteriorly that extends beyond the center of
the valve. ;

Observations.—This species appears to be a true Acrotreta with the apical callosity elon-
gated by the elongation of the ventral valve. The dorsal valve is more convex than in most
species of Acrotreta, which gives a stronger relief to the ridges on the cast between the cardinal
sears and the median ridge. The posterior view (Pl. LX XVI, fig. 1k’) should be compared
with the same view of the dorsal valve of Acrotreta sagittalis (Salter) and its varieties (Pl.
LXXI, figs. 11’, 1m’, and 3¢’’; and Pl. LXXII, figs. le’ and 1f’). The fretted surface is of
the same type as that of several other species of the genus.

Matthew had very little material when he described the species [1886, p. 33]; subsequently
[1895a, p. 127] he created the variety ovalis from a more elongated ventral valve. In the col-
lection made for the United States National Museum by Loper, there are a number of ventral
and dorsal valves. The range of variation in outline appears to cover the variety ovalis.
Some are more transverse than the original type of the species and others nearly as elongate
as the variety ovalis. I have therefore considered the variety as within the original species.
Some of the shells show elongation and others are broadened by distortion.

Matthew [1895a, p. 127] called attention to the resemblance of this species to Linnarssonia
and Acrotreta, and when describing the genus Acrothyra suggested [1901b, p. 304] that it might
belong to that genus. It appears, however, to be a true Acrotreta. A series of specimens, sup-
plemented by the types and a number of ventral valves received from Doctor Matthew which
he had [1895a, p. 126] provisionally identified as ‘‘Acrotreta gemma Billings?” show a rather
remarkable variation in outline and position of the apex of the ventral valve. This is illus-
trated by the figures on Plate LX XVI, also by a number of specimens not illustrated. The
narrow forms, var. ovalis Matthew, have the apex extended beyond the posterior margin,
and in the broad forms the apex is above or in advance of the posterior margin, but if the
shells are compressed vertically the apex may be pushed out over the false area whether the
shell be narrow or broad. I think that in the normal form the false area is vertical or slightly
inclined backward.

ForMATION AND LOCALITY.—Middle Cambrian: (2f and 2g)¢ Sandstones of Division 1bl of Matthew’s [1895a,
p. 108] Protolenus zone, Hanford Brook, St. John County, New Brunswick, Canada.

aThe specimens in the United States National Museum collections to which these numbers are assigned were collected at the type locality
but later than the type specimens.

692 CAMBRIAN BRACHIOPODA.

V, ACROTRETA KUTORGAL Walcott.
Text figure 58; Plate LXV, figures 3, 3a-e, 3e—-k.

Acrotreta kutorgai Watcorr (in part), 1902, Proc. U. S. Nat. Mus., vol. 25, pp. 589-590. (Described as a new species,
but owing to a different interpretation of the structural characters of the ventral valve the description differs
from the one given below. Specimens now referred to Acrotreta rudis were included with true representatives
of A. kutorgai in this description.)

The external characters of the ventral valve are clearly exhibited (Pl. LXV) by figures
3, 3a, and 3d, and what is known of the interior by figures 3b and 3c. Figure 3g is that of a
most interesting specimen, as it clearly shows the cast of the cardinal area of the dorsal valve
adjusted against the false area and pseudodeltidium of the ventral valve. In 1902 (p. 589)
I considered this cast of the cardinal area of the dorsal valve to be the true area and pseudo-
deltidium of the ventral valve, and figure 3g was drawn to bring out this interpretation.

Figure 58 represents a view into the interior of the cast, showing the cast of the false area
and pseudodeltidium of the ventral valve, as well as the cast of the cardinal area of. the dorsal
valve. The cardinal area of the dorsal valve is well
defined in the casts represented by Plate LXV, figures
3h-j. The median ridge of the dorsal valve is as long
proportionally as that of A. bisecta, and like it varies in
length and size in different shells.

The outer surface is marked by fine concentric striz
and lines of growth.

Observations.—This pretty species occurs attached

: to the surface of siliceous nodules in association with

Figure 58—-Acrotreta kuforgai Walcott. View into Qlenoides curticei, Crepicephalus texanus, Acrothele bellula

interior, the specimen being tipped, as shown in the é
side outline. A vertical view of thesamespecimen Walcott, and casts of Medusz. The outline of the con-
1S SO eV eure oe _ vexity of the valves and the posterior view of the ventral

Chess ielee, Meten GS NeiMus Gal Noamrmy, valve is most like that of A. Gitenuata) Meeks) baueuhe

= interior markings are quite unlike.

The specific name was given in honor of Kutorga.

FoRMATION AND LOCALITy.—Upper Cambrian: (361) Shaly limestone in suburb of Attalla, Etowah County,
Alabama.

(1070 and 107u) Limestones and shales at the base of the Knox dolomite, west of the topof Copper Ridge, near
the Southern Railway cut, about 10 miles (16.1 km.) northwest of Knoxville [Keith, 1896b, areal geology sheet],
Knox County, Tennessee.

Middle Cambrian: (90b) Conasauga limestone in cut on Louisville and Nashville Railroad, near Woodstock,
Bibb County; (90) Conasauga (“Coosa”) shale on Edwards farm, near Craigs Mountain, about 10 miles (16.1 km.)
southeast of Center, Cherokee County; (140) limestone interbedded in shales near Chepultepec, Blount County;
(90x) in and attached to the outer surface of siliceous nodules in the Conasauga (‘‘ Coosa”) shale, Coosa Valley, Cherokee
County; (187) shales on the southeast side of the northeast end of the Cane Creek Mountains, 3 miles (4.8 km.) south
of Gadsden, Etowah County; and (139a) limestones on road near Wades Gap, near Chepultepec, Blount County; all
in Alabama.

Specimens that are somewhat doubtfully referred to this species occur at the following
localities:
Middle Cambrian: (142) Shales just above the Olenellus zone, near the railroad, 4.5 miles (7.2 km.) north of
Montevallo, Shelby County, Alabama.
(18) Limestone 1 mile (1.6 km.) east of Gap Creek, 13 miles (20.8 km.) S. 75° E. of Knoxville, Knox County,
Tennessee,
ACROTRETA LISANI Walcott.

Plate LX VIII, figures 3, 3a-c.

Acrotreta liani Waxcorr, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 300. (Described and discussed as below as a new
species. Li San’s name was at that time believed to be correctly written as Lian, hence the form of the
specific name. )

Shell small, about 1.5 mm. in diameter; outline of aperture subcircular, the posterior
side being slightly transverse. Ventral valve conical, with the apex a little in advance of

ACROTRETID. 693

the posterior margin; false area indefinite, except for a rather strong ng, shallow furrow that
extends from the apex to the margin. The elevation of the valve is about two-thirds its
diameter at its aperture. Dorsal valve slightly convex, apex margimal. Surface of shell
marked by fine, concentric striz and lmes of growth that on the dowel valve tend ‘to form
low ridges toward the outer margins.

Observations.—This species is the representative of the American Acrotreta idahoensis
sulcata Walcott. It has the same type of false area, and the ventral valve is of average height.

The specific name is given in recognition of Li San, Mr. Willis’s faithful Chinese interpreter.

ForMATION AND LOCALITY.—Middle Cambrian: (€22) Changhia limestone in upper oolitic portion [ Blackwelder,
1907a, pp. 22 and 33 (part of last list of fossils)], at Changhia, Shantung, China.

ACROTRETA MARJUMENSIS Walcott.
Plate LX XVIII, figures 2, 2a—d.

Acrotreta marjumensis WaucoTT, 1908, Smithsonian Misc. Coll., vol. 538, No. 3, pp. 94-95, Pl. IX, figs. 2 and 2a. (De-
scribed and discussed as below as a new species. Figs. 2 and 2a are copied in this monograph, Pl. LX XVIII,
figs. 2 and 2c, respectively.)

The general form of this species ig much like that of Acrotreta idahoensis Walcott. The
ventral valve differs in having a more strongly marked and broader false area and in the
greater curvature of the apex over the false area. It is also less elevated, or convex, in pro-
portion to the size of the shell. It may also be compared with A. neboensis Walcott, from
which it differs in being less elevated and in not having a well-indicated false pedicle furrow.
The dorsal valve is moderately convex and differs little from the dorsal valve of A. 1dahoensis
and A. neboensis.

The intericr of the dorsal valve shows a narrow median ridge that, at the center and
toward the front of the shell, rises as a sharp, rather high, and very narrow ridge. This ridge
starts posteriorly from a subtriangular, somewhat elevated area which has a longitudinal
furrow erossing it. The cardinal and aemirel muscle scars are very clearly defined; in some
cases the central scars are slightly depressed, and in other shells elevated above the general
surface of the interior of the shell.

The specific name is derived from Marjum Pass, near the type locality.

FORMATION AND LOCALITY.—Upper Cambrian: (33d) Thin-bedded blue limestone at the base of the first high
point southwest of the J. J. Thomas ranch, on the east side of the Fish Spring Range, Juab County, Utah.

Middle Cambrian: (lin) Abowt 3,000 feet (914.4 m.) above the Lower Cambrian and 1,400 feet (426.7 m.) below
the Upper Cambrian, in the wpper part of the limestone forming 1a of the Marjwm limestone [ Walcott, 1908f, p. 179], in
the long cliff 2 mites (3.2 km.) southeast of Marjwm Pass, House Range | Walcott, 1908f, Pls. XIII and XV], Millard
County, Utah.

ACROTRETA MICROSCOPICA (Shumard).

L Plate LX VII, figures 1, la—h, lo, 2, 2a-d.
Discina microscopica SHUMARD, 1861, Am. Jour. Sci., 2d ser., vol. 32, p. 221. (Described as a new species.)

The external outline, form, and convexity of the two valves are so fully illustrated by the
figures that I will only call attention to the variation im the outline of the elevation of the
ventral valve. In Plate LXVII, figure 1d’’, the false area slopes backward imstead of forward
as in other specimens. The lines of growth show that the growth of the anterior portion of the
shell was much more rapid than on the posterior face, thus causing the apex to tip back toward
the area, a feature not observed in the other specimens illustrated. The concentric surface
striz are sharp, but very fine. The only interior of a ventral valve found is represented by

_ figures lo, 1o’, and 10’’

The typical forms from Texas are represented by Plate LX VII, figures 1, la—h, and 1o, and
what appears to be an identical form from Nevada by figures 2, 2a-d. The latter form shows
about the same range of variation in outline and position of the apex of the ventral valve as the
typical forms from Texas. This species belongs to the group of forms with a wide false area.
Tt differs from A. idahoensis Walcott and A. curvata Walcott in the form of the ventral valve.

694 CAMBRIAN BRACHIOPODA.

Acrotreta microscopica has remained without illustration for many years. J made a large
collection in Burnet County, Texas, in 1884, which was increased by Cooper Curtice in 1890.
We found the little shell in great numbers associated with characteristic Upper Cambrian
fossils. In the Eureka district, Nevada, there is a small species of Acrotreta, which, so far as
can be determined from the material available for study, is identical with the A. microscopica as it
occurs in the Upper Cambrian limestones of Texas. It has essentially the same range of varia-
tion in the form of the ventral valve, and the dorsal valves also appear to be identical. (Com-
pare figs. 1 and 2a (the latter has been broadened by pressure); figs. 1d’ and 2’; and the side
outlines 1a and 2c; and 1b’’ and 2b.) The ventral valves have the same outline and convexity.
The outlines of the convexity of figures le-g should be more nearly as in figures 1h and 2d and
not concayo-convex as shown on the plate.

FoRMATION AND LOCALITY.—Upper Cambrian: (67) Sandstone on Tatur Hill, 7 miles (11.2 km.) northwest of
Burnet, Burnet County; and (70e) limestone near Morgans Creek, Burnet County; (69) limestone near Honey Creek,
Burnet County; (71) limestone in Cold Creek Canyon, Burnet County; (68 and 68e) limestone in Packsaddle Mountain,
Llano County; (14b) limestone on Cold Creek at north end of gorge opposite the north end of Sponge Mountain, 2 miles
(3.2km.) south of the San Saba County line, in Llano County; (14g) limestone 1 mile (1.6 km.) west of Cherokee, San
Saba County; and (14e) limestone in Bartlett Hollow, 2 miles (3.2 km.) southeast of the mouth of Falls Creek, Burnet
quadrangle (U. 8. Geol. Survey), Lampasas County; all in Texas.

(12p) About 225 feet (69 m.) above the igneous rocks, in the limestones of the Reagan sandstone, at the northwest
extremity of the Arbuckle Mountains, about 4 miles (6.4 km.) east of Homer, Carter County; (12n) limestones of the
Reagan sandstone (in the section 7 miles (11.2 km.) north of Springer this horizon is about 240 feet (73m.) above the
porphyry contact and 40 feet (12 m.) below the Arbuckle limestone), NW. } sec. 1, T. 28., R. 1 E., Ardmore quad-
rangle, Carter County; (12k) limestones of the Reagan sandstone (in the section 7 miles (11.2 km.) north of Springer
this horizon is about 225 feet (69 m.) above the porphyry contact and 55 feet (17 m.) below the Arbuckle limestone),
on the west side of Honey Creek, near the southeast corner of sec. 35, T. 1 8., R. 1 E., Ardmore quadrangle (U.S.
Geol. Survey), Carter County; and (9r and 9t) about 45 feet (14 m.) and 170 feet (52 m.), respectively, above the por-
phyry contact in the limestones of the Reagan sandstone, SE. + NE. } sec. 2, T. 4 N., R. 13 W., 15 miles (24.2 km.)
northwest of Fort Sill, Comanche County; all in Oklahoma.

Upper? Cambrian: (80) Limestone on the slope of the ridge where the range swings around to the northwest, 2
miles (3.2 km.) north of Aurum, Schell Creek Range, White Pine County, Nevada.

Middle Cambrian: (58) Shaly limestones in upper beds of Secret Canyon shale, east side of New York and
Secret canyons, Eureka district [Hague, 1892, Atlas], Bureka County, Nevada.

L ACROTRETA MICROSCOPICA MISSOURIENSIS Walcott.
Plate LX VII, figures 4, 4a—b.

Acrotreta microscopica missouriensis Waucorr, 1902, Proc. U. S. Nat. Mus., vol. 25, p. 590. (Described as below as a
new variety.)

The shell is uniformly larger and the vertical median line of the false area more depressed, ~
incurved, and distinct than those of Acrotreta microscopica (Shumard) and the variety teton-
ensis Walcott. Some of the specimens of the ventral valves beautifully illustrate the effects
of compression. One shell (Pl. LX VII, figs. 4’ and 4’’) is like that of Acrotreta attenuata Meek
and the other (PI. LX VII, figs. 4a and 4a’) resembles the low form of A. ophirensis Walcott with
the apex overhanging the false area. The surface of the shells embedded in the fine-grained
sandstone has a papillose surface resulting from the indenting of the shell by the grains of sand,
whereas those from limestone are marked only by fine concentric striz.

FoRMATION AND LOCALITY.—Middle Cambrian: (11k) Sandstones of the “‘Hdgewise beds,” beneath the Elvins forma-
tion, St. Francois County; and (lie) thin-bedded limestones south-southwest of Potosi, Washington county; both in
Missouri.

ACROTRETA MICROSCOPICA TETONENSIS Walcott.

\/ ‘Plate LXVII, figures 3, 3a-d.

Acrotreta microscopica tetonensis Watcotr, 1902, Proc. U. S. Nat. Mus., vol. 25, p. 590. (Characterized as below as
a new variety.)
This neat little shell possesses the characters of Acrotreta microscopica (Shumard) and
A. idahoensis Walcott, but differs from both by the projection of the apex of the ventral valve

ACROTRETIDA. 695

over the false area. All that is known of it is represented by the illustrations (Pl. LXVII,
figs. 3, 3a—d).
The varietal name is derived from the Teton Mountains, Wyoming.
FoRMATION AND LOCALITY.—Middle Cambrian: (4e) Limestones about 950 feet (289.6 m.) above the uncon-
formable base of the Cambrian in the divide at the head of Jackson Creek (locally known as Sheep Creek), a creek

flowing into Jackson Lake about 0.5 mile (0.8 km.) south of its northwestern corner, Teton Mountains, Grand Teton
quadrangle (U. S. Geol. Survey), Uinta County, Wyoming.

ACROTRETA? MINIMA (Barrande).
Plate LX XVII, figures 7, 7a.

Obolus? minimus BARRANDE, 1879, Systéme silurien du centre de la Bohéme, vol. 5, pt. 1, Pl. XCY, figs. m: 1-5.
(Not described, but figured as a new species. Figs. 3A and 1A are reproduced in this monograph, Pl. LX XVII,
figs. 7 and 7a, respectively.)

This minute shell may possibly belong with <Acrothele, but with the data furnished by
the illustrations of Barrande [1879b, Pl. XCV, figs. 11:1-5] a provisional reference is made
to Acrotreta. It certainly is not an Obolus. The figures illustrate all the characters known.

ForRMATION AND LOCALITY.—Lower Ordovician: (303d [Barrande, 1879b, Pl. XOV]) Etage dl, Swarow, Bohemia,

Austria-Hungary.
ACROTRETA MISERA (Billings).

v Plate LX XII, figures 2, 2a-1.

Obolella ? miser Brttines, 1872, Canadian Naturalist, 2d ser., vol. 6, No.4, pp. 470-471. (Described and discussed.)

Obolella? miser Brutines, 1874, Geol. Survey Canada, Paleozoic Fossils, vol. 2, pt. 1, p. 69. (Copy of preceding refer-
ence.)

Lnnnarssonia misera (Billings), MatrHew, 1886, Trans. Roy. Soc. Canada for 1885, Ist ser., vol. 3, sec. 4, No. 4,
pp. 35-36, Pl. V, figs. 12, 12a-e. (Described and discussed.)

Linnarssonia misera (Billings), Harn and CrarKe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, pp. 108-109,
Pl. III, figs. 35-37. (Mentioned. Figs. 35 and 36 are drawn from the specimens figured by Matthew, 1886,
Pl. V, figs. 12c and 12, respectively.)

Acrotreta miser (Billings), Waucort, 1902, Proc. U. S. Nat. Mus., vol. 25, pp. 590-591. (Described essentially as
below.)

The abundant material representing this species that I collected in Newfoundland gives
illustrations that present its characters with such fullness and detail that minute description
is unnecessary. Plate LX XII, figures 2, 2a-e of the ventral valve, show variation in outline,
also of the cast of the apical callosity, cardinal scars, and base of main vascular sinuses. Figures
2h-—1 illustrate the interior of the dorsal valve.

The outer surface is marked by fine concentric striae and growth lines, and the inner
layers or lamellze by very fine radiating strie. The minute pedicle aperture is on the back
side of the apex, opening almost posteriorly in some examples.

. This is a small species, averaging from 1.5 to 2.5 mm. in length.

ForMATION AND LOCALITY.—Middle Cambrian: (1 and 2) Shales of zones A and B, respectively, of No. 7 of the
Manuels Brook section [Walcott, 1891b, p. 261], Manuels Brook, Conception Bay; (314 [Billings, 1872b, p. 470])
Paradoxides zone on Chapple Arm, Trinity Bay; (314h) shale on Manuels Brook, Conception Bay; (6g) limestone near
the base of the Middle Cambrian, northwest side of Chapple Arm Harbor, about 1 mile (1.6 km.) from its head, Trinity
Bay; (6h) limestone in the southwest cove of Chapple Arm, Trinity Bay; and (6r) limestone on the west side of
Manuels Brook, Conception Bay; all in Newfoundland.

(2s and 2t) Shales and interbedded limestones in the upper part of the Paradoxides zone, Hastings Cove [Matthew,
1898b, p. 38], on Kennebecasis Bay, 0.5 mile (0.8 km.) northeast of Torryburn, on the Intercolonial Railway, north-

east of St. John; and (3011 [Matthew, 1886, p. 36]) shale of Division 1d of Matthew, on Porters Brook, St. Martins;
both in St. John County, New Brunswick, Canada.

ACROTRETA NEBOENSIS Walcott.
Plate LX XVII, figures 9, 9a-b.
Acrotreta neboensis Waucort, 1905, Proc. U. S. Nat. Mus., vol. 28, pp. 300-301. (Described as below as a new species.)

Ventral valve moderately elevated, the apex projecting slightly over the nearly vertical false
area. The latter is marked midway by a very narrow false pedicle furrow. The transverse

696 CAMBRIAN BRACHIOPODA.

dorsal valve has a strong median depression which starts on the umbo and widens out rapidly
toward the front.

The surface of the shell is marked by concentric ridges and lines of growth and very fine
concentric striz.

Observations.—This is one of the Acrotreta idahoensis forms of the genus. It differs from
other described forms in the strong median depression of the dorsal valve.

The specific name is derived from Mount Nebo Canyon, the type locality.

ForMATION AND LOCALITY.—Middle Cambrian: (14t) Limestone lying on slope between the Cambrian quartzite
and the massive blue limestone 100 feet (30.5 m.) above, in Mount Nebo Canyon, 3 miles (4.8 km.) southeast of Mona,
Juab County, Utah.

ACROTRETA NICHOLSONI Dayidson.

Plate LX XIII, figures 1,ta=k, 6, 6a-b.

Acrotreta? nicholsoni Davipson, 1868, Geol. Mag., vol. 5, pp. 3138-314, Pl. XVI, figs. 14-16. (Described and discussed
as a new species; see below for copy of description. Figs. 14, 15, and 16 are reproduced in this monograph,
Pl. LX XIII, figs. 1, 1c, and 1d, respectively.)

Acrotreta? nicholsoni Davison, 1871, British Fossil Brachiopoda, vol. 3, pt. 7, No. 4, pp. 3438-344, Pl. XLIX, figs. 36-40.
(Described and discussed. Figs. 36, 37, and 40 are copied from figs. 15, 14, and 16, respectively, of the preceding
reference. Figs. 38 and 39 are reproduced in this monograph, Pl. LX XIII, figs. la and 1b, respectively.)

Acrotreta nicholsoni Davidson, SwANSTON, 1877, Proc. Belfast Naturalists’ Field Club, Appendix 4 for 1876-77, Pl. VII,
figs. 2la-c. (Not described. Figs. 21b and 21c are copied from Davidson, 1868, Pl. XVI, figs. 14a and 14b.)

Acrotreta nicholsoni Davipson, 1883, British Fossil Brachiopoda, vol. 5, pt. 2, p. 213, Pl. XVI, figs. 21-23. (New
localities mentioned and new figures given. Figs. 2la, 21c, 21b, 22a, 22b, 21d, and 22c are reproduced in this
monograph, Pl. LX XIII, figs. le-1k, respectively.) .

Acrotreta nicholsoni Davidson, SwANSTON, 1886, Systematic Lists, Flora, Fauna, Paleontology, and Archeology, North
of Ireland, vol. 1, Pl. VII, figs. 21a-c. (Reprint of Swanston, 1877, Pl. VII, figs. 21a-c.)

Acrotreta nicholsoni Davidson, Haut and CusrKe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, p. 103, fig. 59.

(Mentioned in the text and fig. 59 copied from Davidson, 1868, Pl. XVI, fig. 16a.)

The original description by Davidson follows:

Shell small, about 2 lines in length by about the same in breadth, almost circular; rather wider and broadly rounded
anteriorly; nearly straight posteriorly; dorsal valve very slightly convex; ventral valve conical; apex subcentral
and truncated by a minute circular foramen, situated at a little more than one-third of the length of the valve. From
the center of the posterior margin a narrow groove or channel extends to the base of the foramen, while on either side
a small, flattened triangular space or false area (?) is limited by an indented line. Surface of both valves marked
with numerous concentric lines of growth. :

Subsequently Davidson obtained some less-compressed specimens and reillustrated [1883,
Pl. XVI, figs. 21-23] the species. In order to bring before the student all available information
I have reproduced most of Davidson’s figures.

Observations.—A. nicholsoni is one of the largest species of the genus and one of the latest
in point of time. Davidson [1883, Pl. XVI, figs. 21-23] illustrates specimens 5 to 6 mm. in
leneth, and it ranges up into the Llandeilo.

The strongly marked false area and the high ventral valve serve to distinguish this species.

The specific name was given in honor of Nicholson.

FORMATION AND LOCALITY.—Lower Ordovician: (316 [Davidson, 1871, p. 343]) Upper Llandeilo (?) black shales, at
Dobbs Linn, near Moffat, Dumfriesshire; and (316a [Davidson, 1883, p. 213]) Llandeilo at Craighead, Ardmillan Brae,
and Balcletchie, all in the Girvan district of Ayrshire; both in Scotland.

(317 [Davidson, 1883, p. 213]) Coalpit Bay, County Down, Ireland.

Upper Cambrian: (304h) Shineton shales at Mary Dingle, South Shropshire; and (304a [Groom, 1902, p. 110])
“Bronsil’’ shales, Malvern Hills; both in England.

ACROTRETA NOX Walcott.

Vay

- Plate LX XVII, figure 10.
Acrotreta nox Waxcort, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 301. (Characterized as below as a new species.)
This minute shell, 1 mm. in length, is characterized by its low ventral valve, nipple-like
apex, and apparently smooth surface.

FORMATION AND LOCALITY.—Upper Cambrian: (10v) Shales in “‘St. Croix sandstone,’’at Fox Glen, 8 miles (12.8 km.)
east of Baraboo, Sauk County, Wisconsin.

—

ACROTRETID. 697

ACROTRETA @LANDICA Westergard.

Acrotreta oelandica WESTERGARD, 1909, Medd. fran Lunds Geol. Faltklubb, Ser. B, No. 4 (Aftryck ur K. Fysiografiska
Sallskapets Handl., N. F., Bd. 20), p. 76, Pl. V, figs. 24a-b. (Described in Swedish as a new species; see below
for translation. ) :

The original description by Westergard follows:

Apex situated near the posterior border. Along the latter there is a faintly defined triangular area which occupies
one-fourth of the periphery of the shell. The shell is about half as high as broad. Surface smooth, with fine distinct
growth lines, which, although more faintly, are also to be seen on the area. The slope from the apex to the anterior
border is slightly concave, though this is likely a secondary phenomenon due to pressure. The apex itself has not
been preserved.

FORMATION AND LOCALITY.—Upper Cambrian: (310r) Zone v of the Ceratopyge slate at Ottenby, Oeland Island; and
(810s) uppermost part of the alum slate in beds equivalent to the Ceratopyge slate, northern part of Oeland Island;
both [Westergard, 1909, p. 76] in Sweden.

ACROTRETA OPHIRENSIS Walcott.
Plate LX XIV, figures 1, la—p.

Acrotreta ophirensis Waucort, 1902, Proc. U.S. Nat. Mus., vol. 25, pp. 591-592. (Described as below as a new species. )

General outline transversely broad oval, sometimes nearly circular, with the posterior
margin slightly indented midway on the ventral valve by incurving to the false pedicle furrow.
The ventral valve is convex and moderately elevated, the highest point being in front of the
pedicle aperture at about one-third the diameter of the shell. Pedicle aperture large for the
size of the shell and opening either directly or obliquely backward; one specimen shows an
obscure, short, narrow, triangular false area, with a vertical furrow crossing it (Pl. LX XIV,
fig. 1a’’); false area scarcely defined ‘by the cardinal slopes, which incurve very gently; median
furrow well defined, rather strong, and nearly flat on the bottom, the margins being sharply
outlined in many specimens. Some of the shells curve over the false area so that the depressed
apex extends slightly beyond the posterior margin, but generally it is directly on the line of,
or a little in front of, the posterior margin.

Longitudinal diameter of average size ventral valve 3 mm., Svith! a length of 2 to 2.5 mm.
elevation, 1.5 mm. A few shells have nearly the same [omen and width. The convexity of
the dorsal valve averages 0.75 mm. The minute beak of the dorsal valve curves down to the
posterior margin from the somewhat swollen posterior third of the valve.

Surface marked by fine concentric strize and lines. of growth, some of which form con-
centric ridges. The shell is built up of a thin outer layer and numerous thin inner layers or
lamelle that are oblique to the outer layer over the central and outer portions, the obliquity
increasing toward the outer anterior and lateral margins.

The interior of the ventral valve shows a siihen strong apical callosity that ‘extended
nearly to the posterior inner margin of the shell; distinct, but relatively small cardinal scars,
and narrow main vascular sinuses that may be traced nearly to the anterolateral margins of
the valve. The outlines of the visceral cavity are indicated on one well-preserved cast of the
interior of the valve (Pl. LX XIV, fig. le). The interior of the dorsal valve shows great varia-
tion in the size and length of the median ridge and cardinal and central scars; these characters
are fully shown in the numerous illustrations of the interior and casts of the imterior of the
dorsal valve.

Observations.—This species is most closely related to Acrotreta curvata Walcott. It differs
in the ventral valve being larger, in the apex being less extended over the false area, and the
form of the median furrow, which is like that of A. attenuata Meek. Although the shells occur
in a compact unaltered limestone, there is more or less distortion in the outline of both valves;
this, taken in connection with the variation in form and size of the vascular markings, muscle
sears, and median ridge of the dorsal valve, might serve to discriminate several so-called varie-
ties, but I have given names to only two of the more pronounced varieties.

698 CAMBRIAN BRACHIOPODA.

Similar forms occur in a compact, dark, bluish-gray limestone more than 200 miles to
the north in the Wasatch Mountains, east of Cache Valley, on the line of the Ute Peak section
of the Fortieth Parallel Survey.

The specific name is derived from Opie the type locality.

FoRMATION AND LOCALITY.—Middle Cambrian: (3e) Limestone less than 400 feet (121.9 ™.) above the quartzitic
sandstones of the Cambrian, at Ophir, Oquirrh Range, Tooele County, Utah.

(30n) About 3,750 feet (1,143 m.) above the Lower Cambrian and 650 feet (198 m.) below the Upper Cambrian,
in the shaly limestones forming 1c of the Weeks limestone [Walcott, 1908f, p. 175], on the north side of Weeks Canyon,
about 4 miles (6.4 km.) south of Marjum Pass; (30g) about 2,350 feet (716.3 m.) above the Lower Cambrian and 2,050
feet (624.8 m.) below the Upper Cambrian in the limestone forming 1c of the Marjum limestone; and (8x and 3y) about
2,200 feet (670.6 m.) above the Lower Cambrian and 2,200 feet (670.6 m.) below the Upper Gamage f in the shaly lime-
stones forming 1d of the Marjum limestone [Walcott, 1908f, p. 180]; in the ridge east of Wheeler Amphitheater; all
in the House Range [Walcott, 1908f, Pl. XIII], Millard County, Utah.

(31z and 55t) About 350 feet (106.7 m.) above the Brigham quartzite in limestone of the Ute limestone [Walcott,
1908f, p. 7], on west side of road, 0.5 mile (0.8 km.) above the forks, Paradise Dry Canyon (locally known as East
Fork), east of Paradise, Cache County, Utah.

ACROTRETA cf. OPHIRENSIS Walcott.

Numerous compressed specimens of shells about the size of Acrotreta ophirensis Walcott
occur in strata of Middle Cambrian age at various localities in Utah. They resemble the latter
species in size, occasional strong lines of growth, position of the apex of the ventral valve, and
strong cardinal muscle scars in the dorsal valve; they differ in being much less convex, and in
having only a trace of shell substance; the removal of the shell by solution and the compression
in the shale accounts very largely for the differences. The stratigraphic position of the two
forms is about the same and they both lived in the eastern portion of the Cordilleran Middle
Cambrian Sea.

FoRMATION AND LOCALITY.—Middle Cambrian: (32j) 625 feet (190.5 m.) above the top of the Cambrian quartzitic
sandstone in pinkish-colored very fine grained arenaceous shale, 2 miles (3.2 km.) southeast of Muskrat Spring, on
the northwest face of Grantsville Peak, Stansbury, Range, Tooele County, Utah.

(31v) 650 feet (198.1 m.) above the Lower Cambrian and 3,750 feet (1,143 m.) below the Upper Cambrian, in shales
at the top of the limestone forming la of the Howell formation [ Walcott, 1908f, p. 182], northeast side of Dome Canyon,
about 4 miles (6.4 m.) west-southwest of Antelope Springs; (1ly and 30g) about 2,350 feet (716.3 m.) above the Lower
Cambrian and 2,050 feet (624.8 m.) below the Upper Cambrian in 1c of the Marjum limestone [ Walcott, 1908f, p. 180],
ridge east of Wheeler Amphitheater; and (81s) 490 feet (149.4 m.) above the Lower Cambrian and 3,925 feet (1,196.3 m.)
below the Upper Cambrian, in the pinkish argillaceous shale forming 1d of the Howell formation [Walcott, 1908f, p.
182], south side of Dome Canyon about 1 mile (1.6 km.) below the divide, and 3 miles (4.8 km.) west-southwest of
Antelope Springs; all in the House Range [Walcott, 1908f, Pls. XIII and XVI], Millard County, Utah.

(31c) About 900 feet (274.3 m.) above the Brigham quartzite and 3,300 feet (1,005.8 m.) below the Upper Cam-
brian, in the limestone forming 1b of the Ute limestone [Walcott, 1908f, p. 196], in Blacksmith Fork Canyon, about 10
miles (16.1 km.) east of Hyrum, Cache County; (32c) about 60 feet (18.3 m.) above the Brigham quartzite [Walcott,
1908a, p. 8], in green shale, 1 mile (1.6 km.) northwest of Geneva (Copenhagen), east of Brigham, Boxelder County;
and (80u) about 250 feet (76.2 m.) above the Cambrian quartzitic sandstones in sandy shales, 4 miles (6.4 km.) northwest
of Promontory Point (on the ‘‘Lucin cut-off’? of the Union Pacific Railway), about halfway up west end of ridge,
north of Great Salt Lake, Boxelder County; all in Utah.

ACROTRETA OPHIRENSIS DESCENDENS Walcott.
Plate LX XVIII, figures 1, la=c.

Acrotreta ophirensis descendens Waucort, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, p. 95, Pl. IX, figs. 1 and la.
(Discussed as below as a new variety. Figs. 1 and 1a are copied in this monograph, Pl. LX XVIII, figs. 1 and 1c,
respectively.)

In the Cambrian section of the House Range, Utah, the typical forms of Acrotreta ophir-
ensis occur in the Marjum limestone; 1 ,070 feet higher in the section, in the Weeks limestone,
there are great numbers of a shell identical in many respects. This latter shell differs from the
typical form in being less convex in both the ventral and dorsal valves, and im haying a more
pointed, less curved apex on the ventral valve.

ACROTRETID. 699

This form owes its varietal name to the fact that it occurs higher in the section than the
species, and is probably descendant from it.

FORMATION AND LOCALITY.—Middle Cambrian: (30n) About 3,750 feet (1,143 m.) above the Lower Cambrian and
650 feet (198 m.) below the Upper Cambrian in shaly limestones forming 1c of the Weeks limestone [Walcott, 1908f,
p- 175], on the north side of Weeks Canyon, about 4 miles (6.4 km.) south of Marjum Pass, House Range [Walcott, 1908f,
Pl. XIII], Millard County, Utah.

ACROTRETA OPHIRENSIS RUGOSA Walcott.
Plate LXXIV, figures 2, 2a-e.
Acrotreta ophirensis rugosus Waucorr, 1902, Proc. U.S. Nat. Mus., vol. 25, p. 592. (Characterized as below as a new
variety. )
This form is associated with Acrotreta ophirensis Walcott in considerable numbers. It is

characterized by strong, rugose growth lines and thicker shell.

FORMATION AND LOCALITY.—Middle Cambrian: (8e) Thin-bedded limestone, less than 400 feet (121.9 m.) above
the quartzitic sandstones of the Cambrian, at Ophir, Oquirrh Range, Tooele County, Utah. —

; ACROTRETA OVALIS Walcott.

ve
Plate LX VI, figures 2, 2a-b.

Acrotreta ovalis Waxcort, 1902, Proc. U. 8. Nat. Mus., vol. 25, p. 592. (Characterized as below as a new species.)

In material received from the Geological Survey of Canada in answer to a request for the
specimens representing Acrotreta gemma Billings, there was one ventral valve embedded in a
smooth, dove-colored limestone from Poimt Levis. This specimen differs materially from A.
gemma in the oval outline of the rim of the shell, less elevated apex, and less well-defined false
area. It is more of the type of A. schmalenseer Walcott, and of A. microscopica (Shumard) of
the interior continental species than any of the Atlantic Province forms.

FORMATION AND LOCALITY.—Lower Ordovician: (319 [Geol. Survey, Canada]) Limestone No. 1 of Billings’s Point
Levis Section, Point Levis, Province of Quebec, Canada.

ACROTRETA PACIFICA Walcott.
a Plate LXIX;, figures 6, 6a-e.

Acrotreta pacifica Waucorr, 1905, Proc. U.S. Nat. Mus., vol. 28, p. 301. (Described below as a new species.)

Ventral valve a high cone, with the apex a little in advance of the posterior margin; base
circular, with the exception of a slight flattening on the posterior side; apex acute and pointing
upward; false area only a slight flattening of the shell from the apex to the margin. The
Jargest ventral valve has a diameter and height of about 1.5 mm. Surface marked by fine
concentric striz that continue without noticeable deflection across the false area.

Observations.—Only two specimens of the ventral valve of this species occur in the collec-
tion. One of these has a slightly transverse, broadly oval base, and a more definite false area.
‘The species is closely related to Acrotreta idahoensis alta Walcott except that the ventral valve
is not quite as elevated.

FORMATION AND LOCALITY.—Middle Cambrian: (C1 and C2) Lower shale member of the Kiulung group [Black-
welder, 1907a, pp. 37 and 40 (part of the 3d list of fossils) and fig. 10 (beds 4 and 5), p. 38], 2 miles (3.2 km.) south of
‘Yenchuang; (C12) gray limestone near the top of the middle limestone member of the Kiulung group [ Blackwelder,
1907a, pp. 37 and 41 (part of the first list of fossils) and fig. 10 (bed 7), p. 38], 3.25 miles (5.2 km.) southwest of Yen-
chuang; (€5) lower limestone member of the Kiulung group | Blackwelder, 1907a, pp. 37 and 39 (first list of fossils), and
Sig. 8a (bed 30), p. 29], 3.2 miles (5.1 km.) southwest of Yenchuang,; and (C4) limestone nodules at the base of the lower
shale member of the Kiulung group [Blackwelder, 1907a, pp. 37 and 40 (2d list of fossils), and fig. 10 (bed 4), p. 38],
3 miles (4.8 km.) southwest of Yenchuang; all in the Sintai district, Shantung, China.

ACROTRETA PARVULA (Wallerius).
Plate LX XVII, figures 4, 4a.

-Obolella parvula WatLERIUS, 1895, Undersdkningar 6fver Zonen med Agnostus levigatus i Vestergétland, pp. 65-66,
figs. $a-d. (Described in Latin, and discussed in Swedish.)
_Acrotreta parvula (Wallerius), Waucort, 1902, Proc. U.S. Nat. Mus., vol. 25, p. 592. (Described as on p. 700.)

700 CAMBRIAN BRACHIOPODA.

Shell minute, subcircular. Ventral valve relatively depressed, the highest point being at
the umbo, from which there is a slight downward curvature to the apex. False area low and
about vertical, the apex being on a line with the posterior margin. Dorsal valve slightly convex;
beak marginal. Surface marked by fine concentric striz.

Observations—This minute species occurs with Agnostus levigatus in the upper portion of
the Middle Cambrian. It is of the Acrotreta sagittalis (Salter) type, but does not appear to be
identical with the young of that species.

FoRMATION AND LOCALITY.—Middle-Upper Cambrian: (310i) Passage beds between the Middle Cambrian Para-
doxides forchhammeri zone and the Upper Cambrian Olenus truncatus zone, limestone at Borgholm, Oeland Island,
Sweden.

Middle Cambrian: (320) Gudhem, 12.5 miles (20.1 km.) south-southeast of Skara; and (320a) Djwpadal, 19 miles
(30.6 km.) south-southeast of Skara; both [Wallerius, 1895, p. 66] in the Province of Skaraborg, Sweden.

|

AcROTRETA PRIMZVA Walcott.
Plate LXIX, figures 1, la-t.

Acrotreta gemma Waxcorr (in part) [not Buzines], 1886, Bull. U. S. Geol. Survey No. 30, pp. 98-99, Pl. VIII, figs.
1, la-b. (Specimens now referred to Acrotreta pyxidicula and A. attenuata were included with the specimens
representing A. primzva when this description of A. gemma was written, but they were not figured. The two
specimens represented by figs. 1b and 1, la are redrawn in this monograph, Pl. LXIX, figs. 1c and 1, respectively.)

Acrotreta gemma Waxcorr (in part) [not Brries], 1891, Tenth Ann- Rept. U. 8. Geol. Survey, p. 608, Pl. LX VII,
figs. 5c, 5d, and 5e (not figs. 5, 5a-b, see below). (Figs. 5c, 5d, and 5e are copied from figs. la, 1, and 1b, respec-
tively, of preceding reference. Specimens now referred to Acrotreta attenuata, A. idahoensis alta, and A. curvata
were included with the specimens representing A. primzva in this reference to A. gemma, but only the last two
were figured: A. idahoensis alta, Pl. LX VII, figs. 5 and 5a, and A. curvata, Pl. LX VII, fig. 5b.)

Acrotreta gemma Watcort (in part) [not Brxres], 1899, Mon. U. 8. Geol. Survey, vol. 32, pt. 2, p. 449, Pl. LXII,
figs. 2, 2b, and 2d (not figs. 2a, 2c, and 2e, see below). (Figs. 2, 2b, and 2d are copied from Walcott, 1886b, Pl.
VIII, figs. 1, la, and 1b, respectively. Specimens now referred to Acrotreta pywidicula, A. attenuata, A. idahoensis
alta, and A. curvata were included with the specimens representing A. primexva when this description of A.
gemma was written, but only the last two were figured; A. idahoensis alta, Pl. LXII, figs. 2a and 2c, and A.
curvata, Pl. LXII, fig. 2e.)

Acrotreta primaxa Waxcort, 1902, Proc. U. S. Nat. Mus., vol. 25, p. 593. (Described essentially as below as a new
species. )

Acrotreta gemma Walcott, Grapau and Sumer [not Brzines], 1907, North American Index Fossils, vol. 1, p. 199,
figs. 234a-c. (Described, and figures copied from Walcott [1886b, Pl. VIII] figs. 1a, 1, and 1b, respectively.)

Outline of valves transversely oval to subcircular. Ventral valve subconical, with the
apex at the summit of the false area near or just above the posterior margin. The elevation
varies from one-half to two-thirds the diameter of the shell. The false area is quite clearly
defined in most specimens; it varies in width at the posterior margin from one-third to nearly
one-half of the diameter of the shell; the path of advance of the pseudodeltidium is marked
usually by a narrow incised line similar to that of Acrotreta attenuata Meek. Foraminal aper-
ture minute and situated at the apex of the cone. Dorsal valve slightly convex, with a minute
beak slightly incurved over the posterior margin. <A broad, slightly defined median sinus
flattens the front and central portion of the valve, but it is not perceptible toward the umbo
and beak. Surface of the shell marked by fine concentric striz and occasional ridges of growth;
on some shells there is a very fine, almost microscopic, irregular, concentric striation that gives a
fretted surface somewhat similar to that of Obolus (Westonia) ella (Hall and Whitfield). The
inner lamelle of the shell and the interior surface have traces of fine radiating striz that, with
the irregular concentric strix, give a broken, subimbricated, fretted effect to the surface. The
shell is formed of a thin outer layer and several thin inner layers or lamellz, the outer ones
of which are slightly oblique to the outer surface layer. The largest shells have a transverse
diameter of 5.5 mm., longitudinal diameter 5 mm., height of ventral valve 3 mm.; dorsal valve
1mm. The interior of a slightly crushed ventral valve, figure le, shows the cast of an apical
callosity, strong vascular canals, and faint outlines of the visceral cavity. The cast of an
interior of a dorsal valve has a long, well-defined median ridge, cardinal scars, and faintly
defined central scars, as illustrated by figures 1d and 1f. Interiors of the ventral valve from near

ACROTRETIDA. 701

Cherry Creek show two relatively small cardinal scars near the posterior margin, and a small
subtriangular apical callosity.

CQiaemnaniions —This, the oldest species ‘of the genus known to me, has all the essential
characters of the type species as far as the available information permits of comparison. It
is one of the largest shells of the genus, and is a striking feature of the fauna of the higher
portion of the Olenellus zone of central Nevada. The most nearly related species appears to
be A. attenuata Meek (Pl. LXIV, fig. 1).

ForMATION AND LOCALITY.—Middle Cambrian: (7j) Limestones at the north end of the Quinn Canyon Range,
1 mile (1.6 km.) northwest of the Italian Ranch foothills, Nye County, Nevada.

Lower Cambrian: (41) Limestone in the Pioche formation [Walcott, 1908a, p. 11] on a ridge 2.5 miles (4 km.)
northwest of the town of Cherry Creek, White Pine County; and (81a) limestone and interbedded siliceous shales of the
Pioche formation [ Walcott, 1908a, p. 11], just above the quartzite on the east side of the anticline, near Pioche, Lincoln
County; both in Nevada.

ACROTRETA PyxXIDICULA White.

Plate LXIX, figures 2, 2a-f, 3, 3a-f.

Acrotreta pyxidicula Wurtz, 1874, U. S. Geog. Surveys W. 100th Mer., Prelim. Rept. Invertebrate Fossils, p. 9.
(Described as a new species.)

Acrotreta pyxidicula Wurtz, 1877, U. S. Geog. Surveys W. 100th Mer., vol. 4, pt. 1, pp. 538-54, Pl. III, figs. 3a-d.
(Described essentially as in preceding reference. The specimens represented by figs. 3a-b and 3c-d are
redrawn in this monograph, Pl. LXIX, figs. 2 and 2f, respectively.)

Acrotreta gemma Waxcorr (in part) [not Brotmyes], 1884, Mon. U. 8. Geol. Survey, vol. 8, pp. 17-18. (Specimens
representing Acrotreta attenuata, A. curvata, and A. idahoensis alta were included with the specimens representing
A. pyxidicula when this description of A. gemma was written, but only the last two are known to have been
figured: A. curvata, Pl. I, figs. ld and le, and A. idahoensis alta, Pl. I, figs. la and 1b. The specimens repre-
sented on Pl. IX, figs. 9 and 9a, can not be positively located at this time, but it is probable that they should
be referred to A. idahoensis alta.) f

Acrotreta gemma Watcorr (in part) [not Briines], 1886, Bull. U. 8. Geol. Survey No. 30, pp. 98-99. (Specimens
now referred to Acrotreta attenuata and A. primxva were included with the specimens representing .4. pyxidicula
when this description of A. gemma was written, A. primexva being figured, Pl. VIII, figs. 1, la-b.)

Acrotreta gemma Waucorr (in part) [not Brtives], 1891, Tenth Ann. Rept. U. 8. Geol. Survey, p. 608. (Specimens
now referred to Acrotreta attenuata, A. curvata, A. idahoensis alta, and A. primxva were included with the speci-
mens representing A. pyxidicula in this reference to A. gemma, the last three being figured: A. cwrvata, Pl.
LXVII, fig. 5b; A. idahoensis alta, Pl. LX VII, figs. 5 and 5a; and A. primexva, Pl. LXVII, figs. 5c, 5d, and 5e.)

Acrotreta gemma Watcort (in part) [not Bites], 1899, Mon. U. S. Geol. Survey, vol. 32, pt. 2, p. 449. (Specimens
now referred to Acrcireta attenuata, A. curvata, A. idahoensis alta, and A. primxva were included with the speci-
mens representing A. pyxidicula when this description of A. gemma was written, the last three being figured: A.
curvata, Pl. LXII, fig. 2e; A. idahoensis alta, Pl. LXII, figs. 2a and 2c; and A. primeva, Rl. LXII, figs. 2, 2b,
and 2d.)

This is a small and very pretty species in which the interiors of the two valves are fairly
well shown by casts. A marked feature of the ventral valve is the very strong vascular sinus
(fig. 3f), and of the dorsal valve the thickening of the shell in the posterior portion (fig. 3e).
The surface of the shell is marked by fine concentric striz and occasional lines of growth. It is
one of the small species of the genus,.the average size being from 1.5to2 mm. Of the known
species it may be compared with A. idahoensis Walcott (Pl. LXV) from which it differs in the
slighter elevation of its ventral valve and the incised median line on the false area.

FoRMATION AND LOCALITY.—Upper Cambrian: (818f) Limestone at Schellbourne, Schell Creek Range, White Pine
County, Nevada.

(329d) Limestone near Fish Springs, Fish Spring Range, Juab County, Utah.

Middle Cambrian: (7j) Limestone at the north end of the Quinn Canyon Range, 1 mile (1.6 km.) northwest of the
Italian Ranch foothills, Nye County; and (60) limestone in upper beds of Secret Canyon shale, across the canyon from
the dump of the old Richmond mine shaft, Eureka district [Hague, 1892, Atlas], Eureka County; all in Nevada.

(30z) About 2,450 feet (746.8 m.) above the Lower Cambrian and 1,950 feet (594.4 m.) below the Upper Cambrian, in
the upper part of the limestone forming 1c of the Marjum limestone [Walcott, 1908f, p. 180], in the long cliff about
2 miles (3.2 km.) southeast of Marjum Pass, House Range [Walcott, 1908f, pls. XIII and XV], Millard County, Utah.

(5b and 54s) Dark blue-gray Langston limestone [Walcott, 1908f, p. 198], just above the Cambrian quartzitic sand-
stones, north side of Twomile Canyon, near its mouth, 2 miles (3.2 km.) southeast of Malade, Oneida County; (59f)
limestones immediately underlying the Spence shale member of the Ute limestone [Walcott, 1908a, p. 8], in a saddle

702 CAMBRIAN BRACHIOPODA.

north of the creek which flows into Mill Canyon from the west, about 5 miles (8 km.) west-southwest of Liberty and 15
miles (24.2 km.) west of Montpelier, Bear Lake County; and (322) limestone (stratigraphic position unknown) about
6 miles (9.6 km.) west-southwest of Liberty and 15 miles (24.2 km.) west of Montpelier, Bear Lake County; allin Idaho.

(4h) About 375 feet (114.3 m.) above the base of the Cambrian in the limestone interbedded in the Flathead
shales of Peale [1893, p. 21], 1 mile (1.6 km.) north of the junction of East Gallatin and West Gallatin (Gallatin) rivers,
4 miles (6.4 km.) east-northeast of Logan, Threeforks quadrangle (U. 8. Geol. Survey), Gallatin County, Montana.

ACROTRETA RUDIS Walcott.
Plate LXV figure 3f; Plate LXXV, figure 1.

Acrotreta kutorgai Waucorrt (in part), 1902, Proc. U. S. Nat. Mus., vol. 25, pp. 589-590. (Described as a new species,
but the description included specimens belonging to both Acrotreta kutorgat and A. rudis.)
Acrotreta rudis Waucotr, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, pp. 95-96, Pl. IX, fig. 5. (Described and dis-

cussed as below as a new species. Fig. 5 is copied in this monograph, Pl. LXV, fig. 31.)

The specimens illustrating this species are all more or less crushed and flattened on the
surface of the fine argillaceous shale in which they are embedded in large numbers, and they
are often in the condition of casts of the interior of the valves. This is well shown by the
enlargement of a fragment of the shale on which three ventral and three dorsal valves occur
(Pl. LXXYV, fig. 1).

The ventral valve, as far as can now be determined, was elevated, conical, and with the
apex overhanging the false area, so that when the shells were crushed down the posterior side
disappeared beneath. A few fragmentary specimens show the false area to have been distinctly
defined, of medium height, and marked by a narrow, shallow median furrow extending from
the apex to the margin of the valve. Dorsal valve subcircular, slightly transverse, gently
convex, and with a minute beak at the posterior margin. The pedicle opening appears to
have been of medium size and situated at the apex of the valve.

Surface marked by lines of growth and very fine concentzic strie that continue across
the false area and furrow.

The cast of the interior of the ventral valve shows a small but well-defined visceral area
in advance of the apex and a short strong main vascular sinus on each side of the area; one
cast shows traces of the sinuses nearly to the front margin. The interior of the dorsal valve is
marked by a strong median septum or ridge that extends from the front of a small cardinal
area forward nearly to the anterior margin in some examples. A large, oval cardinal muscle
scar occurs on each side of the median ridge near the posterior border of the valve; the central
muscle scars are small, elongate oval and situated on the sides of the median ridge at about
the posterior third of the longitudinal axis of the shell; the two anterolateral muscle scars
are on the sides of the median ridge a little in advance of the central scars.

This is one of the large species of the genus. A dorsal valve 4 mm. in length has a width
of 4.5mm. The ventral valves average from 4 to 4.5 mm. from the apex to the front margin.

In size and outline this species may be compared with Acrotreta depressa (Pl. LXVI, figs.
8, Sa-c) and A. definita (Pl. LXIV, figs. 2, 2a-g). It differs from both in its ventral valve
being more elongate. All the specimens of A. rudis are so flattened in the shale that com-
parison with uncompressed specimens is very difficult.

FORMATION AND LOCALITY.—Middle Cambrian: (101a) Rogersville shale, just above the road in the hill west of the
schoolhouse, 3.5 miles (5.6 km.) southwest of Rogersville on the road to Melinda Ferry | Keith, 1896a, areal geology sheet];
(102c) first shale south of the Estillville pike, 3.5 miles (5.6 km.) east of Rogersville, Greeneville quadrangle (U. S.

Geol. Survey); and (121) Rogersville shale, road just east of Harlan Knob, 4 miles (6.4 km.) northeast of Rogersville
[Keith, 1905, areal geology sheet]; all in Hawkins County, Tennessee.

ACROTRETA SABRIN# (Callaway).
Plate LX XIII, figures 5, 5a-d.

Metoptoma sabrine Cauuaway, 1874, Quart. Jour. Geol. Soc. London, vol. 30, pt. 1, p. 196. (Name proposed, not
described.)

Obolella sabrinee Canuaway, 1877, idem, vol. 33, pt. 1, p. 669, Pl. XXIV, fig. 12. (Described as a new species. The
specimen represented by fig. 12 is redrawn in this monograph, Pl. LX XIII, fig. 5b.)

ACROTRETIDZ. 703

Obolella sabrine (Callaway), Davipson, 1883, British Fossil Brachiopoda, vol. 5, pt. 2, p. 211, Pl. XVI, figs. 27, 27a,
27d, 28, and 28a. (Described and discussed.) ?

Obolella? scabrine (Callaway), Waxcorr, 1884, Mon. U. 8. Geol. Survey, vol. 8, Pl. I, fig. 1c. (Not described, and
figure copied from Davidson, 1883, Pl. XVI, fig. 27d.)

Obolella sabrine (Callaway), Haru and CuarKe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, p. 103, fig.
58. (Mentioned in the text and figure copied from Davidson, 1883, Pl. XVI, fig. 27d.)

Acrotreta sp. cf. nicholsoni Davidson, MatiEy, 1902, Quart. Jour. Geol. Soc. London, vol. 58, pt. 1, p. 142, fig. 10.
(Discussed in text as Acrotreta sp., and figured as A. sp. ci. nicholsoni.)

Acrotreta (?) sabrine (Callaway), Marty, 1902, idem, p. 143. ,(Discussed.)

Acrotreta (?) sabrine malvernensis MatiEy, 1902, idem, pp. 143-144, figs. 11-14. (Described and discussed as a new
variety.)

Acrotreta sp. ci. A. socialis von Seebach, Mariey, 1902, idem, pp. 144-145, figs. 15 and 16. (Characterized and dis-
cussed.)

As in the case of most species of Acrotreta preserved in shales, the ventral valves of this
-form are so compressed as to prevent our getting the true elevation. With several fairly well-
preserved specimens to judge from I think the height was about two-thirds of the greatest diam-
eter of the shell. A’ partial cast of the interior shows a small apical callosity and the base
of the cast of a small pedicle tube. The interior of the dorsal valve is almost bisected by a
strong median ridge; the cardinal scars are also prominent.

A fragment of the outer shell shows fine, concentric strie and lines of growth that are
fretted by very fine undulating strie.

Through the courtesy of Dr. Charles Lapworth I have had the opportunity of studying and
illustrating the type specimen of Callaway’s ‘“‘Obolella sabrine”’ (Pl. LX XIII, fig. 5b). It is
a cast of the dorsal valve preserving little more than the impression of the strong median ridge
and a trace of the area. Dr. Lapworth also sent me several other specimens of this species;
these are illustrated on Plate UX XIII, figures 5, 5a, 5c, and 5d. Davidson [1883, Pl. XVI,
fig. 27d] illustrates an interior of a dorsal valve in which the median ridge and the cardinal
and central scars are clearly defined. He also gives [1883, Pl. XVI, figs. 27, 27a] the exterior
of a compressed ventral valve and a side view of the two valves united.

Of described species, Acrotreta bisecta Matthew approaches this most closely. It is quite
probable that with a good series of specimens of each species for comparison the two forms
would be referred to the one species of Callaway.

Matley [1902, p. 148, figs. 11-14] illustrates amd describes some crushed specimens from
the lowest black shales of the Malvern Hills, which he tentatively gives the value of a variety
of this species under the name malvernensis. With examples from the typical locality before
me for comparison with the proposed variety, 1 am inclined to consider the latter of such
doubtful value as to leave it out of this work.

He also [Matley, 1902, p. 144] mentions an Acrotreta as sp. cf. A. socialis yon Seebach
from a higher stratigraphic horizon. Acrotreta socialis as now restricted is confined to the
Middle Cambrian. I do not think that the material as illustrated and described by Matley
clearly indicates a form distinct from Acrotreta sabrine, if allowance is made for the crushed
condition of most specimens of the latter species. The shell mentioned as Acrotreta sp. cf.
nicholsoni [Matley, 1902, p. 142] may also be a large specimen of this species.

The shells figured by Matley [1902, p. 141, figs. 7 and 8] as Lingulella (?) sp. and [1902,
p. 142, fig. 10] as Lingula (?) sp. I think are either Acrotreta or Acrothyra, probably the latter.

FoRMATION AND LOCALITY.2—Upper Cambrian: (304h and 304i [ Callaway, 1877, p. 669]) Shineton shale, at Shineton,
Mary Dingle, Dryton, Cressage, 1 mile (1.6 km.) west of Cressage, west of Harley, and under Cownd- Moor quarry, all in
South Shropshire, England.

(304p) Shineton shales at the following localities of the Geological Survey of Great Britain: 2495, 2536, 2543,
2545, 2558, and 2580, all of which are on Shineton Brook, South Shropshire, England.

(304j) Lower Stockingford shales, Puxley Park lane, halfway up the path to the quarry, Atherstone, Warwick-
shire; (304a [Groom, 1902, p. 110]) ““Bronsil” shales, Malvern Hills; and (304b [Groom, 1902, p. 109]) lower part of
the ‘‘White Leaved Oak” shales (the zone of Polyphyma), Malvern Hills; all in England.

a Localities 304h and 304j are the only localities represented in the United States National Museum collections. 304h is the type locality.

704 CAMBRIAN BRACHIOPODA.

ACROTRETA SAGITTALIS (Salter).
Plate LX XI, figures 2, 2a—h, 3, 3a-j.

Vbolella sagittalis Saurmr, 1866, Rept. British Assoc. Ady. Sci. for 1865, p. 285. (Name proposed.)

Discina labiosa SautER, 1866, idem, p. 285. (Name proposed.)

Obolella sagittalis Salter, Davipson, 1868, Geol. Mag., vol. 5, pp. 309-310, Pl. XV, figs. 17-24. (Described and dis-
cussed. )

Obolella sagittalis Salter, Davison, 1871, British Fossil Brachiopoda, vol. 3, pt. 7, No. 4, pp. 339-340, Pl. L, figs.
1-14. (Copy of preceding reference. Figs. la, 3a, 4 and 4a, 5 and da, 9, 10 and 10a, and 12 and 12a appeared,
Davidson, 1868, Pl. XV, as figs. 17a, 21a, 23 and 23a, 19 and 19a, 22a, 20 and 20a, an 24 and 24a, respectively.)

Obolella saeinialio Salter, LINNARSSON, 1876, Byles till K. svensk. Vet. eNiek Handl., Bd. 3, No. 12, pp. 19-20, Pl.
III, figs. 36-41. (Described sad dscreved in English.)

Obolella sagittalis Salter, LriyNARSSON, 1879, Sveriges Geol. Undersdkning, Afhandl. och Uppsatser, Ser. C, No. 35,
pp. 27-28, Pl. III, figs. 45-49. (Described in Swedish. )

Obolella sagittalis Salter, BréccER, 1882, Die silurischen Etagen 2 und 3, p. 45, Pl. X, figs. 6-8. (Described and
discussed in German.)

Obolella sagittalis Salter, Davipson, 1883, British Fossil Brachiopoda, vol. 5, pt. 2, p. 211, Pl. XVI, figs. 25-26. (Gives
new localities and new figures.)

Linnarssonia sagittalis (Salter), Waucort, 1885, Am. Jour. Sci., 3d ser., vol. 29, p. 115, figs. 5 and 8. (Merely refers
the species to Linnarssonia. Figs. 5 and 8 are copied from Davidson, 1868, Pl. XV, figs. 22a and 23a, respec-
tively.)

Obolella ida ? Dawson, 1888, Canadian Ree, Sci., vol. 3, p. 55. (Possible occurrence discussed.)

Obolella ida ? Dawson, 1888, Peter Redpath Museum, Montreal, Canada; Notes on Specimens, April, 1888, p. 55.

Obolella (Linnarssonia) pretiosa Dawson, 1890, Trans. Roy. Soc. Canada for 1889, Ist ser., vol. 7, sec. 4, No. 3, pp.
53-54, figs. 26a-c. (Discussed.)

Linnarssomia cf. pretiosa Dawson, Hat, 1890, idem, p. 55. (Description of the specimens discussed in preceding
reference.)

Linnarssonia sagittalis (Salter), Waucorr, 1891, Tenth Ann. Rept. U.S. Geol. Sina, Pl. LXVIII, oo 2a-d. (Not
described.)

Linnarssonia pretiosa (Dawson), Hann and Cxiarke, 1892, Nat. Hist., New York, Paleontology, vol. 8, pt. 1, p. 70,
Pi. III, figs. 48-44. (Discussed. Figs. 43-44 are copied from Dawson, 1890, figs. 26a—c, p. 53.)

Linnarssonia sagittalis (Salter), Hart and CLarKe, 1892, idem, p. 108, figs. 60-61. (Discussed. The figures are copied
from Davidson, 1868, Pl. XV, figs. 22a and 23a, respectively.)

Linnarssonia pretiosa (Dawson), ScHucHERT (in part), 1897, Bull. U. 8. Geol. Survey No. 87,-p. 262. (Mere reference,
but includes specimens now referred to both Acrothele pretiosa and Acrotreta sagittalis.)

Linnarssonia sagittalis (Salter), Frrcu, 1897, additional plates inserted in 1897 in Lethzea geognostica, pt. 1, Lethza
paleeozoica, Atlas, 1876, Pl. IA, fig. 3a. (No text reference. Fig. 3ais copied from Walcott, 189la, Pl. LX VIII,
fig. 2.) :

Obolella cf. sagittalis Salter, Wman, 1902, Bull. Geol. Inst. Univ. Upsala, vol. 6, pt. 1, No. 11, p. 66. (New localities
mentioned.)

Obolella (Acrotreta?) sagittalis (Salter), MoBrere and SrcrrBera, 1906, Medd. fran Lunds Geol. Faltklubb, Ser. B,

2 (Aftryck ur K. Fysiografiska Siallskapets Handl., N. F., Bd. 17), p. 64, PI. I, figs. 25 and 26. (Charac-
terized in Swedish.)

?Linnarssonia pretiosa GRaABAU and Sumer, 1907, North American Index Fossils, vol. 1, p. 200. (Described, but
not figured, and it is impossible to tell whether the authors are discussing the L. pretiosa that is now referred
to Acrotreta sagittalis, or the true Acrothele pretiosa.)

Although I have examined a large collection of this species, both Pion Wales and Sweden,
good exteriors of the valves have not been observed. The apex of the ventral valve ellen
invariably remains in the matrix, or the shell has been removed by solution. The convexity
of the two valves is approximately the same (figs. 3c and 3d, Pl. LX-X1) except that the ventral
valve is more elevated near the apex. The apex is situated a little in front of the posterior
margin at the edge of the slightly defined false area which slopes forward at an angle of 70°
to 80°. The surface of the shell is marked by rather strong concentric strize and often
strong ridges of growth and very fine radiating striz on the interior layers. The shell is built
up of thin layers or lamellz of a calcareocorneous nature. The average diameter of specimens
from St. Davids, Wales, is 2.5mm. The representatives of the species from Andrarum, Sweden,
are usually sneillen thorn the St. Davids shells but otherwise appear to be identical.

The interior of the ventral valve is shown by numerous casts. The apical callosity and
the cardinal scars are usually large. The visceral cavity is sometimes outlined in front of the
callosity and between the clearly marked main vascular sinuses. Casts of the interior of the

ACROTRETID. 705

dorsal valve show a remarkable range of variation in the length and size of the median ridge
(Pl. LXXI, figs. 3e, 3e-j). Withim the extremes of variation specific characters could be
established. ,

This species has had a varied experience at the hands of paleontologists. Davidson [1871,
Pl. L, figs. 1-14] elaborately illustrated the casts of the interiors of the valves, and I [1885,
p. 116] copied some of his figures when preparing the description of the genus Linnarssonia.
When in Wales in 1888, I collected a quantity of material at St. Davids, and recently Schmalensee
collected a good series at Andrarum for the United States National Museum. From these col-
lections figures have been drawn that illustrate the appearance of the shells as they occur both
in shale and limestone.

The varieties taconica and transversa are strongly marked, but I think are not entitled to
full Specific valuation. A direct comparison of specimens from the black shales of Little Metis
with those from the black shales of the type locality of A. sagittalis at St. Davids fails to disclose
any specific differences between them, so far as the material at hand permits of comparison.
The Little Metis shell was published as Linnarssoma cf. pretiosa by Hall [1890, p. 55], and this
identification was accepted by Sir William Dawson [1890, p. 53]. “‘Obolella pretiosa” Billings
[1862d, p. 68] is a true Acrothele, and no species of Acrotreta is known to occur at the type
locality on the Chaudiere River. The stratigraphic horizon of the Little Metis beds has not
been definitely determined. Dawson [1890, p. 32] says: “‘At Metis the evidence of the pebbles
in the conglomerates indicates that they are newer than the Lower Cambrian, and the few
fossils found in the sandstones and shales would tend to place them at or on the horizon of
the Chazy.” I personally examined the section at Little Metis in 1899, and am not at all
certain of the horizon of the shales carrying Acrotreta sagittalis and the beautiful fossil sponges
described by Dawson [1890, pp. 37-55]. It is a region of strong folding and thrust faults.
The Acrothele is a Middle Cambrian type, and nothing similar to it is known from the Upper
Cambrian. As far as this shell can locate the horizon, it is Cambrian, and probably low down
in the Upper Cambrian, if not in the Middle Cambrian.

FORMATION AND LOCALITY.—Passage beds between the Upper Cambrian and the Ordovician: (309 [Moberg and
Segerberg, 1906, desc. of Pl. I]) Ceratopyge limestone (Zone 4) at Fogelsang, 5 miles (8 km.) east of Lund, Province
of Malmoéhus, Sweden.

(323 [Wiman, 1902, p. 66]) Phyllograptus slate and Ceratopyge limestone in the Christiania region of Norway; and
(828h [Brogger, 1882, p. 17]) blue Ceratopyge limestone at Vestfossen, 10 miles (16.1 km.) west-southwest of Christiania,
Norway.

Upper Cambrian: (321e-321m [Wiman, 1902, p. 68]) Drift bowlders of Ceratopyge slate, Nos. 1-4, 6-8, 9, 12, 14,
17,,23, and 27, on Biludden, about 20 miles (32.2 km.) east of Gefle, Province of Gefleborg; and (321n [Wiman, 1902,
p. 68]) drift bowlder of limestone (Ceratopyge slate horizon), at Trédje, in Gistrikland; both in Sweden.

(823a [Wiman, 1902, p. 66]) Ceratopyge slate in the Christiania region of Norway.

(818g [Davidson, 1868, p. 310]) Lower Lingula flags at Porth-y-rhaw, Pen-y-pleidiau, and several other localities near
St. Davids, South Wales.

(318¢ [Davidson, 1868, p. 310]) Lower Lingula flags at the Rheider Waterfall Valley and at Gwynfynydd and
other places near Dolgelly, all in North Wales.

Middle? Cambrian (Probably between Middle and Upper Cambrian): (892g [Dawson, 1888a, p. 55]) Black shales
at Little Metis, Province of Quebec, Canada.

Middle Cambrian: (2g) Sandstone of Division Ibl of Matthew’s [1895a, p. 108] Protolenus zone on Hanford
Brook, St. John County; and (2s) limestone in upper part of Paradowides zone, Hastings Cove [Matthew, 1898b, p. 38],
on Kennebecasis Bay, 0.5 mile (0.8 km.) northeast of Torryburn, on the Intercolonial Railway northeast of St. John,
St. John County; both in New Brunswick.

(6g) Limestone near the base of the Middle Cambrian, the lowest horizon carrying Paradoxides, northwest side
of Chapple Arm Harbor, about 1 mile (1.6 km.) from its head, Trinity Bay; (6w) limestone at Seal Point Cove, near
Long Point, Trinity Bay; and (6i) limestone about 300 feet (91.4 m.) below the base of the Upper Cambrian on shore
north of Fosters Point, Random Island, Random Sound; all three in Newfoundland.

(318h) Shales in the Menevian at St. Davids, South Wales.

(316b [ Davidson, 1883, p. 211]) Cairn Burn and Druidhill Burn, both in Dumfriesshire, Scotland.

(8w) Limestones of the Paradoxides forchhammeri zone, at Andrarum, 20 miles (32.2 km.) northwest of Simrisbhamn,
Province of Christianstad; (821y) shale at Andrarum, 20 miles (32.2 km.) northwest of Simrishamn, Christianstad;
and (321z) shales at Fogelsing, 5 miles (8 km.) east of Lund, Province of Malméhus; all in Sweden.

62667°—vou d1, pr 1—12——45

706 CAMBRIAN BRACHIOPODA.

(161) Limestones of the Paradowides davidis zone at Borregaard; (16i) limestones of the Conocoryphe exsulans zone
at Borregaard; (16j) limestones of the Paradoxides forchhammert zone at Laesai; (16h and 334h) limestones of the
Paradoxides forchhammeri zone at Borregaard; and (16k) limestones of the Paradoxides davidis zone at Laesaa; all on
Bornholm Island, Denmark.

Specimens somewhat doubtfully compared with Acrotreta sagittalis occur at the following
locality:

Middle Cambrian: (317a [Davidson, 1871, p. 340]) at Bellewstown, County Meath; and at Balbriggan, County
Dublin; both in Ireland. 4

ACROTRETA cf. SAGITTALIS.

High up in the Middle Cambrian of the House Range, Utah, there is a small, depressed
species of Acrotreta that appears to be identical with A. sagittalis as the latter occurs in Sweden
and Newfoundland. Some of the ventral valves are very low, but sipecuibee of a similar char-
acter occur in the limestones of Sweden and Newfoundland.

ForRMATION AND LOCALITY.—Middle Cambrian: (11n) About 3,000 feet (914.4 m.) above the Lower Cambrian
and 1,400 feet (426.7 m.) below the Upper Cambrian, in the upper part of the limestone forming la of the Marjum
limestone [Walcott, 1908f, p. 179], in the long cliff southeast of Marjum Pass [Walcott, 1908{, Pls. XIII and XV],
House Range, Millard County, Utah.

A somewhat similar shell that also strongly suggests Acrotreta sagitialis occurs in the
Middle Cambrian limestones near Antelope Springs, in the House Range, Millard County,
Utah. As the material is not very good or abundant, nothing more will be done at present
toward identifying it.

" ACROTRETA SAGITTALIS MAGNA (Matthew).

A. Plate LXVI, figures 4, 4a-f.

Linnarssonia belti magna Matrurw, 1897, Trans. Roy. Soc. Canada for 1897, 2d ser., vol. 3, sec. 4, No. 7,pp. 169-170,
Pl. I, figs. la-b. (Described and discussed as a new variety. The specimens represented by figs. la and 1b
are redrawn in this monograph, Pl. LX VI, figs. 4b and 44a, respectively.)

Acrotreta sagittalis magna (Matthew), Waxtcott, 1902, Proc. U. S. Nat. Mus., vol. 25, pp. 595-596. (Discussed as
below.)

In addition to the material collected by Matthew, I have a number of specimens collected
by me at the typical locality at Hastings Cove. A comparison with a series of specimens of
Acrotreta sagittalis (Salter) from St. Davids, Wales, and of A. sagittalis transversa (Hartt)
shows at once that the form Matthew named is very closely related to both. The length and
size of the median ridge, and the position of the central scars of the dorsal valve, and the size
and position of the cardinal scars of the ventral valve are the internal characters that Matthew
depends upon to distinguish the variety magna. All of the characters are fully covered, by
the variations in the same characters in A. sagittalis and its variety transversa. The nearly
circular form of the variety magna is about the only character that can be considered of value, and
that is very closely approached by some specimens of A. sagittalis (Pl. LXXI, figs. 3b, 3e, 3h).

It is not probable that the New Brunswick shell is a variety of Acrotreta beltt (Davidson)
(Pl. LXXVII). In order to have all the data possible for the student I have illustrated
Matthew’s types, which he kindly sent me for the purpose, also specimens I found in the lime-
stone at the base of the beds carrymg Paradoxides at Hanford Brook.

ForMATION AND LOCALITY.—Middle Cambrian: (2s)% Limestones in upper part of Paradoxides zone, Hastings
Cove [ Matthew, 1898b, p. 38], on Kennebecasis Bay, 0.5 mile (0.8 km.) northeast of Torryburn, on the Intercolonial Rail-
way, northeast of St. John; (2i) sandstones of Division 1b3 of Matthew’s [1895a, p. 108] Protolenus zone, Hanford
Brook; and (21) limestones at base of Paradoxides zone, Hanford Brook; all in St. John County, New Brunswick,
Canada.

a 2s is the type locality, though the specimens in the United States National Museum collections to which that number is assigned were
collected later than the type specimens.

> 7
a ee

ACROTRETIDA. 107

ay ACROTRETA SAGITTALIS TACONICA (Walcott).
Plate LX XI, figures 1, la-o.

Finnarssonia taconica Waucotr, 1887, Am. Jour. Sci., 3d ser., vol. 34, pp. 189-190, Pl. I, figs. 18, 18a-d. (Described
and discussed as a new species. The specimens represented by figs. 18a—c are redrawn in this monograph,
Pl. LXXI, figs. lo, le, and 1h, respectively.)

Tnnnarssonia taconica Walcott, Qa 1889, Annuaire aeolesoe universel for 1888, tome 5, p. 1138. (Described
in French in a review of the preceding reference.)

Linnarssonia sagittalis taconica Waucorr, 1889, Am. Jour. Sci., 3d ser., vol. 38, p. 36. (Stratigraphic position
mentioned.)

Linnarssonia sagittalis taconica Watcorr, 1891, Tenth Ann. Rept. U.S. Geol. Survey, pp. 610-611, Pl. LX VIII, figs.
1, la-d. (This description and the figures are copied from Walcott, 1887, p. 189, Pl. I, figs. 18, 18a—d.)

Acrotreta sagittalis taconica WAtcott, 1902, Proc. U. 8. Nat. Mus., vol. 25, pp. 596-597. (Characterized and discussed
as below.) ;

This variety is characterized by the uniformly shorter median ridge of the dorsal valve.
The ventral valve appears to be identical with those of Acrotreta sagittalis (Salter) from Andra-
rum, which are embedded in the same character of matrix as the variety taconica.

This is the second representative of the genus found in association with the Olenellus fauna.
Acrotreta primzva Walcott occurs in the upper zone of the Olenellus fauna in Nevada, and thisis in
the upper portion of the same fauna in the Appalachian region. Its association with Microdiseus
connexus, a representative of Microdiscus punctatus of the Paradoxides zone of New Brunswick,
also serves to connect it with Acrotreta sagittalis. It appears to be one of the few forms that
connect the Atlantic Province Cambrian fauna with that of the Appalachian Province. It has
been found in abundance in the Lower Cambrian of the Canadian Rocky Mountains, thus
extending its range to the Cordilleran Province.

-FORMATION AND LOCALITY.—Lower Cambrian: (36b) Limestone near schoolhouse No. 12, near Greenwich; (338)
limestone in the town of Greenwich; (33 and 338c) limestone at and near Rock Hill schoolhouse, near North Green-
wich; (838e) limestone a little west of North Greenwich; (838f) limestone near Argyle, 8 miles (12.8 km.) north of
Greenwich; (36 and 338d) limestone 1 mile (1.6 km.) south of Shushan; (88x) limestone 0.5 mile (0.8 km.) south of
Coila, just east of Cambridge; (43a) limestone 1 mile (1.6 km.) east-northeast of Salem; (45a) limestone at McNaughton
Corner, 1 mile (1.6 km.) east of Salem; and (37b) limestone 0.25 mile (0.4 km.) east of Salem; all in the Cambridge
quadrangle (U. S. Geol. Survey), Washington County, New York.

(85) Limestones 1.5 miles (2.4 km.) north of Bald Mountain, 3.5 miles (5.6 km.) north-northwest of Greenwich:
and (338h) limestone on the summit of Bald Mountain, about 2 miles (3.2 km.) northwest of Greenwich; both in the
Schuylerville quadrangle (U. S. Geol. Survey), Washington County, New York.

(34) Limestone on roadside a little west of the bridge over Poultney River at Low Hampton, about 5 miles
(8 kim.) east-northeast of Whitehall; (39) limestone south of the Delaware and Hudson Railroad track on the road
running south-southwest from Low Hampton, about 5 miles (8 km.) east-northeast of Whitehall; (45b) limestone
near the roadside about 1,200 feet (366 m.) east of Bristol’s house, near Low Hampton, about 5 miles (8 km.) east-
northeast of Whitehall; and (338a) limestone in the northeast section of Whitehall township; all in the Whitehall
quadrangle (U. S. Geol. Survey), Washington County, New York.

(20a) Gray limestone, interbedded with shaly slates, in a lane west of Lafayette Stevens’s house, about 100 yards
(91.4 m.) from the main road, in the southern part of Whitehall township; (22) limestone 1.5 miles (2.4 km.) north of
North Granville; and (38a) limestone 2 miles (3.2 km.) south of North Granville, on the road which turns south from the
road running between that village and Truthville, 4 miles (6.4 km.) west-northwest of Granville; all in the Fort Ann
quadrangle (U. 8. Geol. Survey), Washington County, New York.

_ (22a) Limestone in Penrhyn quarries, Middle Granville, Mettawee quadrangle (U. S. Geol. Survey), Washington
County, New York.

(838b) Limestone on Kinderhook Creek near Stockport Paper Mill; (29) limestone just above the bridge at the
Stockport Paper Mill, on Kinderhook Creek; (44b) limestone near North Chatham; and (82a) limestone 0.75 mile
(1.2 km.) west of Riders Mills on the Harlem Extension Railroad, about 9 miles (14.4 km.) north-northeast of Chatham;
all in the Kinderhook quadrangle (U. 8. Geol. Survey), Columbia County, New York.

(44a) Limestone on Valatie Kill, near the line between Nassau and Schodack townships, near the line between
the Troy and Kinderhook quadrangles (U. S. Geol. Survey); (838y) limestone north of Eagle Mills; (338) limestone
at Schodack, northeast corner of the Coxsackie quadrangle (U.S. Geol. Survey); and (29a) limestone 1 mile (1.6 km.)
below the New York Central Railroad depot at Schodack; all in Rensselaer County, New York.

708 CAMBRIAN BRACHIOPODA.

(58k) Just below the Middle Cambrian in limestones forming 1 of the Mount Whyte formation [Walcott, 1908c,
p. 240 (9)]; (57m) about 50 feet (15 m.) below the Middle Cambrian in a siliceous shale correlated with 1b of the Mount
Whyte formation on Mount Bosworth [Walcott, 1908f, p. 213]; (57e) about 115 feet (35 m.) below the Middle Cambrian,
in limestone correlated with the top of 1c of the Mount Whyte formation on Mount Bosworth [Walcott, 1908f, p. 213];
(57r and 58s) about 150 feet (46 m.) below the Middle Cambrian, near the base of thelimestones forming 3 of the Mount
Whyte formation [Walcott, 1908¢, p. 241 (10)]; and (35f) about 300 feet (91 m.) below the Middle Cambrian, in the
limestone forming 6 of the Mount Whyte formation [Walcott, 1908c, p. 242 (11)]; all on Mount Stephen, just above
the tunnel on the north shoulder, 3 miles (4.8 km.) east of Field, British Columbia.

(57s) About 160 feet (49 m.) below the Middle Cambrian, near the base of the gray oolitic limestone forming 1b
of the Mount Whyte formation [Waleott, 1908f, p. 212], on Mount Bosworth, north of the Canadian Pacific Railway
between Hector and Stephen, on the Continental Divide between British Columbia and Alberta, Canada.

ACROTRETA SAGITTALIS TRANSVERSA (Hartt).
Plate LX XII, figures 1, la—k.

Obolella transversa Hartt, 1868, Acadian Geology, by Dawson, 2d ed., p. 644. (Characterized.)

Obolella transversa Hartt, 1878, idem, 3d ed., p. 644. (Copy of preceding reference.)

Obolella transversa Hartt, Wancorr, 1884, Bull. U.S. Geol. Survey No. 10, p. 16, Pl. I, figs. 5and5a. (Original descrip-
tion copied and species discussed. ‘The specimens represented by figs. 5 and 5a are not redrawn in this mono-
graph, but better figures of them are given by Walcott, 1891a, Pl. LX VIII, figs. 2a and 2c, respectively.)

- Linnarssonia transversa (Hartt), Watcorr, 1885, Am. Jour. Sci., 3d ser., vol. 29, p. 115, figs. 3, 4,6, and 7, p. 116. (Dis-
cussed as the type of the new genus Linnarssonia. Figs. 3. and 7 are drawn from the specimens figured by Wal-
cott, 1884a, Pl. I, figs. 5 and 5a, respectively.)

Linnarssonia transversa (Hartt), Maram. 1886, Trans. Roy. Soc. Canada for 1885, ‘Ist ser., vol. 3, sec. 4, No. 4, p. 35,
Pl. V, figs. 11, 1la-e. (Discussed. Casts of the two specimens represented by fice. 11, lla-e are Aone iby)
Walcott, 1891la, Pl. LX VIII, figs. 2d and 2a.)

Obolzlla transversa Harr, 1891, Acadian Geology, by Dawson, 4th ed., p. 644. (Copy of Hartt, 1868, p. 644.)

~Linnarssonia sagittalis transversa (Hartt), Waucorr, 1891, Tenth Ann. Rept. U. 8. Geol. Survey, Description of Pl.
LXVIII, figs. 2a, 2c, and 2d. (No text reference. Figs. 2a and 2c are drawn from the specimens figured by
Walcott, 1884a, Pl. I, figs. 5 and 5a, respectively. Fig. 2d is drawn from the specimen figured by Walcott,
1885a, fig. 6, p.116. Figs. 2d and 2a are drawn from casts of the two specimens figured by Matthew, 1886, Pl. V,
figs. 11, 1la-e.)

Linnarssonia transversa (Hartt), Hatt and CrarKe, 1892, Eleventh Ann. Rept. State Geologist New York for 1891,
Pl. Ill, figs. 22 and 23. (Fig. 22 is drawn from the specimen figured by Matthew, 1886, Pl. V, fig. 11.)

Linnarssonia transversa (Hartt), Hatt and CrarxKe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, p. 108, Pl.
III, figs. 38-42. (Mentioned in the text. Figs. 38-39 and 40-42 are drawn from the specimens figured by
Matthew, 1886, Pl. V, figs. 1le and 11, respectively. Figs. 42 and 39 are copied from figs. 22 and 23, respectively,
of the preceding reference.)

Linnarssonia transversa (Hartt), Martaew, 1895, Trans. New York Acad. Sci. for 1894-95, vol. 14, p. 125, Pl. V, figs.
la—c and 2a-c. (Locality menticned. The figures are copied from Matthew, 1886, Pl. V, figs. 11, 1la-e.)

Linnarssonia sagittalis transversa (Hartt), Frc, 1897, Additional plates inserted in 1897 in Lethzea geognostica, pt. 1,
Lethzea palzeozoica, Atlas, 1876, Pl. 1A, fig. 3b. (No text reference. Fig. 3b is copied from Walcott, 1891a, Pl.
LXVIII, fig. 2d.)

This is the representative of Acrotreta sagittalis (Salter) in the Paradoxides zone of New
Brunswick. Many shells are more transverse in outline than the average of A. sagitialis, but
examples of the latter (Pl. LX-XI, figs. 3, 3a, 3g, 3j) are nearly as much so and the interior
casts show a striking similarity in the Welsh and Acadian forms. The range of variation in
each form is nearly as great as the variation between the two. In view of this, I think it is
best to characterize transversa as a variety of A. sagittalis.

The shells from the ‘‘Protolenus beds’”’ of Hanford Brook also vary in form from the nearly
circular variety magna to the transverse forms included under transversa.

ForMATION AND LOCALITY.—Upper Cambrian: (3) Shales 300 feet (91.4 m.) above the Paradoxides zone, Manuels
Brook, Conception Bay, Newfoundland.

Middle Cambrian: (2f and 2g) Sandstones of Division 1b]: (2h) overlying 2¢ in the sandstones of Division 1b2;
(2) sandstones of Division 1b2; (2i) sandstones of Division 1b3; (2k) overlying 2i in the sandstones of Division 1b3;
and (301b) sandstones of Division 1b5 and higher; all in Matthew’s [1895a, p. 108] Protolenus zone, Hanford Brook,
St. John County, New Brunswick.

(301c) Sandstones of the St. John formation, at Coldbrook; and (301k) St. John formation, in the city of St. John;
both in St. John County, New Brunswick.

ACROTRETIDAL. 709

ACROTRETA SCHMALENSEEL Walcott.

Plate LXX, figures 1, la-s.

Not Acrotreta socialis voN SnEBacn, 1865, Zeitschr. Deutsch. geol. Gesell. for 1865, Bd. 17, p. 341, Pl. VIIIa, figs.
14. (This species is referred in this monograph to Acrotreta socialis.)
Acrotreta socialis LINNARSSON [not von SEEBACH], 1876, Bihang till K. svensk. Vet.-Akad. Handl., Bd. 3, No. 12,
pp. 16-18, Pl. III, figs. 32-35. (Described and discussed in English.)
2Acrotreta socialis LINNARSSON, 1877, Geol. Foren. i Stockholm Forhandl., No. 40, Bd. 3, No. 12, p.374. (Not figured,
and may belong with either Acrotreta schmalenseei or A. socialis.)
Acrotreta socialis Linnarsson, WALLERIUS, 1895, Undersékningar 6fver Zonen med Agnostus levigatus i Vestergétland,
p. 66. (Discussed in Swedish.) .
Acrotreta schmalensei Waucott, 1902, Proc. U.S. Nat. Mus., vol. 25, pp. 597-598. (Described as below as a new species.)
As in the case of many other species of this genus, the student is referred to the series
of figures illustrating it for information as to the external outline, form, and convexity of the
two valves and the range of known variation. The collections of the United States National
Museum contain a large series of specimens from which the shells illustrated were selected.

The broad false area has a shallow, famt median groove on some specimens, and on others
no traces of it have been seen. The pedicle aperture, which is exceedingly minute, is situated
at the extreme apex of the ventral valve; the cast of the base of the pedicle tube is clearly
shown in interior casts of the valve (Pl. LXX, figs. 1f and 1h). One of the distinguishing
characters, is the cast of the large maim vascular smuses on each side of the visceral area, a
feature which varies (Pl. LXX, figs. le, 11, and is). The casts of the interior of the dorsal
valve (figs. 1j-1p) are interesting and instructive m showing the considerable variation in
the size and length of the median ridge, and the size of the cardinal and central scars.

The shell is small and built up of a thin outer layer and several inner layers or lamellee
more or less oblique to the outer layer. The outer surface is marked by fine concentric striz
and lines of growth, and the inner surfaces of the lamellz by concentric striz and fine radiating
strie. The average length of the opening of the valves is 1.5 to 2 mm., and the width is usually
a little more.

Observations.—All of the specimens illustrated are from the Paradozides forchhammeri
zone. They appear to be identical with the figures of Acrotreta socialis given by Linnarsson
[1876, Pl. IU, figs. 32-35], but are not like those given by von Seebach [1865, Pl. VIIa, figs.
1-4]. Those of the latter represent a shell with strong concentric strize and median groove
on the false area, characters that Linnarsson states that he did not find on his specimens.
Among the collections made for me by Mr. G. Schmalensee, a collector in the Geological Sur-
vey of Sweden, I find a larger Acrotreta than the one described by Linnarsson [1876, p. 16],
which agrees with the description of A. socialis given by von Seebach [1865, p. 341] and with
his figures. Linnarsson writes that he thinks that von Seebach had representatives of several
species before him when he wrote his notes on A. socialis. With this I fully agree, hut with
the collections now before me from Bornholm and Oeland, I think the specific name A. socialis
should be given to the larger shell, illustrated by von Seebach [1865, Pl. VIIIa, figs. 1-4], and
a new name given to the smaller and very distinct shell illustrated by Linnarsson [1876, Pl.
III, figs. 32-35]. In recognition of the faithful and intelligent work of Mr. G. Schmalensee, I
take pleasure in naming the species in his honor.

Acrotreta schmalenseei is of the type of A. subconica Kutorga, but is much less elevated.
It may be compared with A. microscopica (Shumard) and A. gemma Billings among Amzrican
species.

FORMATION AND LOCALITY.—Middle Cambrian: (8238b) Limestone of the Paradowides wlandicus zone, at Wind-
juelandet, Ringsaker, Province of Hedemerken, Norway.

(320n) Limestones of the Paradoxides forchhammeri zone at Loyened, Djupadal, 19 miles (30.6 km.) south-southeast
of Skara; (320e) limestone at Munkesten, north of Hunneberg; (321q) limestones of the Paradowides JSorchhammeri zone
at Munkesten, north of Hunneberg; and (320m [Linnarsson, 1876, p. 18]) limestone of the Paradoxides forchhammeri
zone at Kinnekulle, northeast of Lidképing; all in the Province of Skarabore, Sweden.

(8w) Limestones of the Paradoxides forchhammeri zone at Andrarum; and (320c [Wallerius, 1895, p. 66]) Andrarum
limestone, at Andrarum,; both 20 miles (32 km.) northwest of Simrishamn, Province of Christianstad, Sweden.

TO CAMBRIAN BRACHIOPODA.

(320d) Hxsulans limestone in the lower part of the Paradoxides tessini zone, at Fogelsang, 5 sores (8 km.) east of
Lund, Province of Malméhus, Sweden.

(310¢ [Wallerius, 1895, p. 66]) Limestone of the Paradowides wlandicus zone, on Oeland Island; (310p [Linnarsson,
1876, p. 18]) limestone of the Paradowxides elandicus zone at Borgholm; and (310b) dark-brown limestone at Borgholm,
on Oeland Island; all in Sweden.

(16j) ibnestoie of the Paradoxides forchhammeri zone at Laesaa; (16h) limestone of the same zone at Borregaard;
and (334 [Wallerius, 1895, p. 66]) limestone of the Paradoxides forchhammeri zone; all on Bornholm Island, Denmark.

ACROTRETA SEEBACHI Walcott.

Plate LX XVII, figures 3, 3a.

Acrotreta seebachi Waucort, 1902, Proc. U. S. Nat. Mus., vol. 25, pp. 598-599. (Described and discussed as below
as a new species. )

Acrotreta seebachi Walcott, MoBERG and SEGERBERG, 1906, Medd. fran Lunds Geol. Faltklubb, Ser. B, No. 2 (Aftryck
ur K. Fysiografiska Sallskapets Handl., N. F., Bd. 17), pp. 66-67. (Characterized and discussed in Swedish.)

Among the fragments of trilobites in the Ceratopyge limestone collected by Schmalensee
there are a few specimens of a species of Acrotreta distinct from A. schmalenseer Walcott and
A. socialis von Seebach. The ventral valve is relatively low, with the false area nearly vertical.
A cast of this valve shows the cardinal scars on each side high up toward the apex; small main
vascular sinuses and apical callosity. False area rather large and marked by a slight indica-
tion of a median depression that is recognized by a slight undulation in the transverse striz.
Surface marked by fine threadlike concentric striz and lines of growth. A broken dorsal
valve has a broad median sulcus and a small distinct beak at the posterior margin. The
valves are slightly transverse. A large ventral valve measures 3 mm. in width by 2.5 mm.
in length.

The surface strize and the cardinal scars serve to distinguish this species from others known
to me. Acrothele? ceratopygarum (Brégger) is from the Ceratopyge shales, but it has a low
ventral valve with the false area sloping forward.

After deciding that a new species was represented in the material received from Schmalen-
see, I studied a fine series of specimens that Dr. W. C. Brégger kindly sent me. In material
collected by Schmalensee from the Ceratopyge shale at Borgholm, Oeland Island, Sweden,
some imperfect specimens suggest Acrotreta seebachi; they might equally well be referred to
A. carinata Moberg and Segerberg, or A. circularis Moberg and Segerberg.

The specific name was given in honor of Dr. K. von Seebach.

FoRMATION AND LOCALITY.2—Passage beds between the Upper Cambrian and the Ordovician: (8x) Ceratopyge,
limestone at Slemmestad, about 3 miles (4.8 km.) southwest of Christiania; (328d) Ceratopyge limestone (Ktage 3a7 of
Brégger) at Christiania; (323f) lower part of the Ceratopyge limestone [Brégger, 1882, pp. 16 and 17] at Vestfossen, 10
miles (16.1 km.) west-southwest of Christiania; (23h) blue Ceratopyge limestone [Brogger, 1882, p. 17] at Vestfossen,
10 miles (16.1 km.) west-southwest of Christiania; and (828e) Ceratopyge limestone at Engervik, near Christiania; all
in Norway.

Upper Cambrian: (310d) Ceratopyge slate at Borgholm, Oeland Island, Sweden.

Specimens somewhat doubtfully referred to this species occur at the following locality:

Passage beds between the Upper Cambrian and the Ordovician: (323g) Ceratopyge limestone (Htage 3ay of
Brégger), at Vaekkerd, in the Christiania region, Norway.

ACROTRETA SHANTUNGENSIS Walcott.
Plate LXIX, figures 5, 5a-e. -

Acrotreta shantungensis WAucorr, 1905, Proc. U. S. Nat. Mus., vol. 28, pp. 301-302. (Described and discussed as below
as a new species.)

Shell small. Ventral valve a low cone with the apex a little forward of the posterior

margin, which is slightly flattened; apex minute, directed backward and projecting slightly .

over the faintly defined false area. The cast of the interior shows that the apical callosity was
rather large and that the main vascular sinuses were well defined on each side of it; the cardinal
scars are coal and not prominent.

a Localities 8x and 310d are represented in the collections of the United States National Museum; the others are in the collection of the
University of Christiania.

— ee ee eT ey Te

—_—

ee a

ACROTRETID. Kall

Dorsal valve slightly convex; apex marginal; surface marked by a rather broad, shallow
median depression that begins on the umbo and gradually widens toward the front margin.
The interior of the dorsal valve has a strong median ridge extending from the posterior margin
two-thirds the distance toward the front. A small, elevated Cardinal scar occurs on each
side of the median ridge a little in advance of the posterior margin. Main vascular sinuses
rather strong; they start beneath the apex and extend forward a short distance from the outer
lateral margin of the shell.

Surface marked by fine concentric striz and lines of growth.

Observations.—This shell in size and general form is closely related to Acrotreta microscopica
(Shumard) (Pl. LX VII) of the Middle Cambrian fauna of the United States.

The specific name is derived from Shantung, China.

FORMATION AND LOCALITY.—Middle Cambrian: (€37) Upper part of the Kichou limestone@ in dense black lime-
stone nodules in green-gray shales 10 feet (3 m.) below the base of the cliff limestone, 8 miles (12.8 km.) south of Ting-
hianghien; and (€71) massive cliff-making limestone in the central portion of the Kichou formation [Willis and
Blackwelder, 1907, pp. 189 and 145 (2d list of fossils)], 4 miles (6.4 km.) southwest of Tungyu, Shansi, China.

(€1) Lower shale member of the Kiulung group [Blackwelder, 1907a, pp. 37 and 40 (part of the 3d list of fossils),
and fig. 10 (bed 4), p. 38], 2 miles (3.2 km.) south of Yenchuang; and (€62) earthy layer in the middle limestone member
of the Kiulung group | Blackwelder, 1907a, pp. 37 and 40 (last list of fossils), and fig. 10 (base of bed 7), p. 38], 2.5 miles
(4 km.) south of Yenchuang, on the north-northeast spur of Hulushan; both in the Sintai district, Shantung, China.

A shell apparently identical with Acrotreta shantungensis was collected at the following
locality:

Middle Cambrian: (C32) A fine-grained, bluish-black limestone bowlder believed to have come from the lower

part of the Kisinling limestone [Blackwelder, 1907b, p. 272], collected in river drift 1 mile (1.6 km.) south of Chon-
pinghien, on Nankiang River, southern Shensi, China.

ACROTRETA SIGNALIS Walcott.
Plate LXIX, figure 4.

Acrotreta signalis Waucotr, 1902, Proc. U. S. Nat. Mus., vol. 25, p. 599. (Described and discussed as below as a new
species.)

‘Ventral valve transverse, broadly ovate; height about one-third the length; apex directed
backward on a line with the posterior margin, which is transverse and slightly undulated at the
center by the median furrow of the false area; apex with a minute apical foramen which is
directed backward. Surface marked by fine concentric striz and lines of growth that at the
median furrow of the false area curve toward the posterior margin.

Shell small, 1.5 mm. long by about 1.75 mm. in width. Shell built up of several very
thin layers or lamelle.

Observations.—In all of the extensive collections made from the Cambrian sandstones of
the upper Mississippi Valley, only two ventral valves of any species of Acrotreta have been
found, as far as known tome. These occur in association with Lingulella (Lingulepis) acuminata
(Conrad) and the shells have the color and appearance of those of that species, shiny light gray
to white, the original coloring matter having been leached out. Only the exterior of the ventral
valve is known. This compared with A. microscopica (Shumard) (Pl. LXVII) shows a less
elevated ventral valve and aless distinct false area. It also has a marked median groove on the
false area. It recalls A. idahoensis Walcott, but differs in being more depressed and in having
a stronger groove on a narrower false area.

FORMATION AND LOCALITY.—Middle Cambrian: (328e) “St. Croix sandstone” at St. Croix Falls, Polk County,
Wisconsin.
ACROTRETA SOCIALIS von Seebach.
Lv
Plate LX XIII, figures 3, 3a-c, 4, 4a-e. .
Acrotreta socialis von SuEpacs [not Linnarsson], 1865, Zeitschr. Deutsch. geol. Gesell. for 1865, Bd. 17, p. 341, Pl.
VIIa, figs. 1-4. (Described and discussed in German, as a new species. Figs. 14 are reproduced in this mono-
graph, Pl. LX XIII, figs. 3, 3a-c, respectively.)

a The fossils from this locality are not listed, but the presence of Cambrian strata at the locality is mentioned by Willis and Blackwelder
[1907, p. 146).

712 CAMBRIAN BRACHIOPODA.

Not Acrotreta socialis LINNARSSON, 1876, Bihang till K. svensk. Vet.-Akad. Handl., Bd. 3, No. 12, pp. 16-18, Pl. II],
figs. 32-35. (Described and discussed in English. This species is referred in this monograph to Acrotreta
schmalenseet.)

2? Acrotreta socialis LINNARSSON, 1877, Geol. Féren. i Stockholm Férhandl., No. 40, Bd. 3, No. 12, p. 374. (Not figured,
and may belong with either Acrotreta socialis or Acrotreta schmalenseet.)

Acrotreta socialis von Seebach, WaucorTT, 1902, Proc. U. S. Nat. Mus., vol. 25, pp. 599-600. (Described and discussed
essentially as below.)

Not Acrotreta cf. socialis MatrHEw, 1902, Bull. Nat. Hist. Soc. New Brunswick, vol. 4, pt. 5, No. 20, pp. 392-394, Pl.
XV, figs. 5a-k. (Described and discussed. This species is referred in this monograph to Acrotreta.sp. undt.)

Not Acrotreta cf. socialis MarrHEw, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, pp. 183-185,
Pl. III, figs. 5a-k. (Copy of preceding reference. This species is referred in this monograph to Acrotreta sp.
undt.) E
The species described and illustrated by von Seebach [1865, p. 341, Pl. VIIa, figs. 1-4] as

Acrotreta socialis is characterized by a well-marked, concentrically striated surface and a strong

median groove in the false area. In the collections made for me by Mr. Schmalensee at Borg-

holm, Oeland Island, I find associated with Paradoxides wlandicus an Acrotreta that has these
characters. All the specimens from the Paradoxdes forchhammeri zone in the large collection
before me, with the exception of one ventral valve, belong to a distinct species which I have

named A. schmalenseei. Von Seebach evidently had specimens of the latter species, also of a

species of Acrotreta from the Ceratopyge limestone, as he mentions the occurrence of A. socialis

at both horizons.

The external form, as far as known to me, is shown by the figures. There is some variation
in the height of the ventral valve and in the outline of the margins of the valves. The false
area is clearly defined and marked by a strong, rather broad median groove. The pedicle
aperture is at the apex of the ventral valve and quite readily seen in several specimens, a char-
acter in strong contrast with the minute aperture at the apex of A. schmalenseer, Walcott.
Shell formed of several thin layers or lamellee that show very plainly where the thin outer layer
is exfoliated. Surface marked by striz and lines of growth that are very distinct on some
shells and less so on others; the concentric strize occur on all the lamellz of the shell and on
the inner surface; fine radiating striz are to be found on the inner surface. The cast of the
interior of the ventral valve shows the presence of a large apical callosity and unusually large
pedicle tube and main vascular sinuses on each side of the visceral cavity. The cardinal scars
are well defined in both the ventral and dorsal valves. Casts of the interior of the dorsal valve

show a strong median ridge, central scars, and fairly well-defined main vascular sinuses. Von >

Seebach [1865, p. 341] describes the surface as having minute warts on it. . I find numerous
fragments of the shell of Acrothele (Redlichella) granulata (Linnarsson) associated with Acrotreta
socialis, and it may be that von Seebach mistook the surface of this shell for that of the species
he was describing. No known species of Acrotreta has such a surface.

A large ventral valve has a diameter of 5 mm. and a height of 2.5 mm. The average size
is about 3 mm. in diameter.

A single ventral valve found by Schmalensee at Andrarum appears to belong to this species.
It is a cast of the interior of the shell, and shows concentric ridges or undulations of growth,
well-defined cardinal scars, large apical callosity, and short but strong main vascular sinuses
(Pl. LXXIII, fig. 4b).

This species belongs to the A. subconica Kutorga group of species with a broad false area
and well-defined median groove. Its surface is more strongly marked by concentric striz than
any other species of the genus, and the shell is also thicker.

Grénwall [1902, p. 39] and Linnarsson [1877, p. 374] refer specimens to Acrotreta socials,
but do not accompany the references by descriptions or figures, and Il therefore can not decide
whether to include the forms with Acrotreta socialis or Acrotreta schmalenseev.

Matthew [1902b, p. 392] has compared some imperfect specimens of a species of Acrotreta
from McNeil Brook, Cape Breton, with Acrotreta socialis von Seebach. The shells, as far as
can be determined, do not belong to this species. They are about the same size, but the ventral
valve is depressed and more like that of Acrotreta sagittalis magna (Matthew). I can not identify

ACROTRETID. 713

the species with the material available for study, and I have entered it in this monograph as
Acrotreta sp. undt. (see p. 715).

ForRMATION AND LOCALITY.—Middle Cambrian: (8z) Limestones of Paradowides elandicus zone, Borgholm, Oeland
Island; (820n) limestones of the Paradoxides forchhammert zone at Lovened, Djupadal, 19 miles (30.6 km.) south-south-
east of Skara, Province of Skaraborg; and (8w) limestones of Paradoxides forchhammeri zone at Andrarum, 20 miles
(32.2 km.) northwest of Simrishamn, Province of Christianstad; all in Sweden. ; :

(884g [Seebach, 1865, pp. 340 and 341]) Limestones on Bornholm Island, Denmark.

ACROTRETA SPINOSA Walcott.
Plate LX XIX, figures 4, 4a-¢.

Acrotreta spinosa Watcort, 1905, Proc. U. 8. Nat. Mus., vol. 28, p. 302. (Characterized as below, as a new species.)

The general form of this shell is much like that of Acrotreta idahoensis Walcott (Pl. LX VIII,
fies. 2, 2a-g). It differs in having a straighter posterior margin. The distinguishing character
of the species is the spinose outer surface. The surface is marked by fine concentric lines of
growth at irregular intervals, with numerous, very fine, threadlike strize between. On some
shells occur radiating, more or less irregular, fine, rounded ridges that are formed by the
elevated elongate spine bases. When these elongate bases are irregularly arranged the radiat-
ing ridges are not present. Owing to their minute size, the spinules are rarely seen.

FoRMATION AND LOCALITY.—Upper Cambrian: (65) Limestone on east side of Sierra Canyon, opposite Pinnacle
Peak; (62a) limestone on east side of Sierra Canyon, opposite the Jackson mine; (62) limestone in the Dunderbere
shale [Walcott, 1908f, p. 184], in canyon immediately north of Adams Hill; and (61) limestone in the Dunderberg shale
[Walcott, 1908f, p. 184], a little south of the Hamburg mine; allin the Eureka district [Hague, 1892, Atlas], Eureka County,
Nevada.

ACROTRETA SUBCONICA Kutorga.
Plate LX XIII, figures 2, 2a-i.

Acrotreta subconica Kurorca [not MEEK], 1848, Verhandl. Russ.-kais. min. Gesell. St. Petersburg for 1847, No. 12,
p. 275, Pl. VII, figs. 7a-c. (Described in German as a new species; see below for translation. Figs. 7a, 7b, 7c,
7b’, and 7c’ are reproduced in this monograph, Pl. LXXIII, figs. 2, 2a-d, respectively. The specimens repre-

_ sented by figs. 7a, 7b’, and 7c’ are redrawn in this monograph, Pl. LX XIII, figs. 2e, 2h, and 2i, respectively.
Figs. 2f and 2g on Pl. LX XIII of this monograph represent one of Kutorga’s type specimens, but he figured
only the dorsal valve, 1848, Pl. VII, fig. 7c’.)

Acrotreta Morris, 1849, Annals and Mag. Nat. Hist., 2d ser., vol. 4, Pl. VII, figs. 4a-b. (No text reference. Figs.
4a and 4b are copied from Kutorga’s figures, 1848, Pl. VII, figs. 7b’ and 7c’, respectively, of Acrotreta subconica.)

Acrotreta subconica Kutorga, Davipson, 1853, British Fossil Brachiopoda, vol. 1, Introduction, No. 3, Pl. IX, figs.
271-275. (Notext reference. Figs. 271-275 are copied from Kutorga, 1848, Pl. VII, figs. 7c, 7a, 7b, 7b’, and 7c’,
respectively.)

_ Acrotreta subconica Kutorga, voN SEEBACH, 1865, Zeitschr. Deutsch. geol. Gesell. for 1865, Bd. 17, p. 341. (Men-
tioned in discussion of A. socialis.)

Not Acrotreta subconica MEEK, 1873, Sixth Ann. Rept. U. 8. Geol. Survey Territories for 1872, p. 463. (This species
“is referred in this monograph to Acrotreta idahoensis.)

Acrotreta subconica Kutorga, QUENSTEDT, 1885, Handbuch der Petrefactenkunde, Aufl. 3, p. 755, Pl. LVIII, fig. 51.
(Mentioned. Fig. 51 is roughly copied from Kutorga, 1848, Pl. VII, fig. 7b.)

Acrotreta subconica Kutorga, Waucorr, 1902, Proc. U. S. Nat. Mus., vol. 25, pp. 600-601. (Original description
translated and type specimens discussed as below.)

The original description by Kutorga follows:

Strongly conical; the deltidium-like furrow narrow and plainly impressed. Innumerable srowth wrinkles run
on the whole surface of the shell horizontally, and make deflections only in the furrow, the convexity of which is
turned toward the base of the cone.

Height of the cone, 0.014; length of the base of the ventral valve, 0.012; breadth of the same, 0.015.

Four specimens, of which one is complete and three are without ventral valve. From the collection of Herr
von Volborth.

On one specimen with the apex broken off I investigated the surface of the fracture under the microscope, with
a magnification of forty-five times, and found on it two cruriform, shallow impressions similar to those on the casts
of the Siphonotretes. Their surface was polished and with impressions of growth folds, and between the extremities
of the crura, in the neighborhood of the area-like hinge surface, a columniform fragment of the mold of the siphon.
From this it follows that the broken-off tip, just as the beak of the Siphonotretes, was solid and contained a cylin-
drical siphon.

714 CAMBRIAN BRACHIOPODA.

Observations.—Through the courtesy and permission of Dr. Fr. Schmidt, Dr. Fr. von Huene
kindly sent me the types of this species, which he had been studying. One of them preserves
the outer shell at the apex. It shows a minute foraminal aperture on the back side of the apex
and a strong median groove on the false area. The outlines of the pedicle valve vary from
the somewhat diagrammatic drawings of Kutorga [1848, Pl. VII, figs. 7a-c], and there is
some variation among the five specimens representing the types. ‘The characters of the shell
are shown by the figures on Plate LX XIII.

FoRMATION AND LOCALITY.—Ordovician: (336) Echinosphxrites limestone, horizon Cla [Fr. Schmidt, personal
communication, 1906], Popowka, near St. Petersburg, Russia.

ACROTRETA ULRICHI Walcott.

Plate LX XVIII, figure 3. fe

Acrotreta ulrichi Waucort, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, pp. 96-97, Pl. IX, fig. 3. (Described and

discussed as below as a new species. Fig. 3 is copied in this monograph, Pl. LX XVIII, fig. 3.)

This species is founded on a single specimen of a finely preserved ventral valve. The
outline of the aperture is nearly circular, except for a short transverse portion beneath the
false area; surface moderately convex, with the apex curving and ending beyond the posterior
margin so that the minute foraminal aperture opens backward; a small false area is indicated
by a slight incurving at the cardinal angles; the area is without traces of a median furrow.

Surface of shell marked by very fine, concentric striz and lines of growth. Length and
width of aperture 2 mm.; convexity of ventral valve 1 mm.

Observations.—This species is characterized by its curved umbo and apex, and overhang-
ing false area. It most nearly resembles A. curvata Walcott, from which it differs in being
less convex, and in the form of its umbo and curved apex.

The specific name was given in honor of Mr. E. O. Ulrich.

FoRMATION AND LOCALITY.—Upper Cambrian: (12p) About 225 feet (69 m.) above the igneous rocks, in the

limestones of the Reagan sandstone, at the northwestern extremity of the Arbuckle Mountains, about 4 miles (6.4
km.) east of Homer, Carter County, Oklahoma.

ACROTRETA UPLANDICA Wiman.
V
Plate LXX, figures 3, 3a-c.
Acrotreta uplandica WmaAN, 1902, Bull. Geol. Inst. Univ. Upsala, vol. 6, pt. 1, No. 11, p. 54, Pl. II, figs. 15-18. (De-
scribed in German as a new species. The specimens represented by figs. 15-18 are redrawn in this monograph,
Pl. LXX, figs. 3, 3a-c, respectively.)
Acrotreta uplandensis (Wiman), Waucort, 1905, Proc. U. 8. Nat. Mus., vol. 28, p. 302. (Characterized as below.)

This species recalls at once Acrotreta idahoensis sulcata Walcott. It differs from it in
having a broader false area. The surface is marked by fine, threadlike striz that cross the
false area and false pedicle groove.

ForRMATION AND LOCALITY.—Middle? Cambrian: (311b) Drift bowlder of gray bituminous sandstone, No. 2 [Wiman,
1902, p. 57], on Biludden, about 20 miles (82.2 km.) east of Gefle, Province of Gefleborg; and (811p) drift bowlder of

glauconitic sandstone, No. 1 [Wiman, 1902, p. 57], at Hoganiis, parish of Borstil, east of Osthammar, Province
of Stockholm; both in Sweden. .

ACROTRETA UPLANDICA LIMOENSIS (Wiman).
Plate LXX, figures 4, 4a-c.

Acrotreta liméensis WiMAN, 1902, Bull. Geol. Inst. Univ. Upsala, vol. 6, pt. 1, No. 11, p. 54, Pl. II, figs. 19-22. (Char-
acterized in German as a new species. The specimens represented by figs. 19-22 are redrawn in this mono-
graph, Pl. LXX, figs. 4, 4a—-c, respectively.)

Acrotreta wplandica limonensis (Wiman), Watcort, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 303. (Characterized) as
on p. 715.) 7 é

|
!

7

ACROTRETIDA. 715

Wiman states [1902, p. 54] that this form is quite like Acrotreta wplandica, but lower, as
the height is only one-third of the diameter. It is so close in all other respects that I do not
think that more than a varietal value should be given to the differences mentioned.

The specific name is derived from Limén Island, Sweden.

FORMATION AND LOCALITY.—Middle? Cambrian: (311n) Drift bowlder of bluish calcareous sandstone, No. 6
[Wiman, 1902, p. 57], on Limon Island, about 12 miles (19.3 km.) east-northeast of Gefle, Provinee of Gefleborg, Sweden.

ACROTRETA sp. undt.

Acrotreta cf. socialis MattHEw [not LINNARSSON or VON SEEBACH], 1902, Bull. Nat. Hist. Soc. New Brunswick, vol. 4,
pt. 5, No. 20, pp. 392-394, Pl. XV, figs. 5a-k. (Described and discussed.)

Acrotreta ci. socialis MatrHEw, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, pp. 183-185, Pl. III,
figs. 5a-k. (Copy of preceding reference.)

Matthew describes and illustrates this form and compares it with Acrotreta socialis von
Seebach. A comparison of his specimens with A. socialis shows the two forms to be distinct.
Matthew’s specimens are more suggestive of A. sagittalis magna (Matthew) (Pl. LXVI, figs.
4, 4a-f) except that the ventral valve is higher.

With the original specimens for study it appears best to indicate this form as an unde-
termined species.

FORMATION AND LOCALITY.—Middle Cambrian: (325a [Matthew, 1903, p. 184]) Shales of Division 02c of Matthew’s
Bretonian, on the eastern slope of the valley of McNeil Brook, on the road to Trout Brook, Cape Breton, Nova Scotia.

ACROTRETA sp. undt. Westergard.

Acrotreta sp. WESTERGARD, 1909, Medd. fran Lunds Geol. Filtklubb, Ser. B, No. 4 (Aftryck ur K. Fysiografiska
Sallskapets Handl., N. F., Bd. 20), pp. 57 and 77, Pl. II, figs. 25a-b. (Locality mentioned in Swedish.)
This species is not described by Westergard, and I have not seen the specimen. It is of
medium height and appears to be a true Acrotreta.
ForMATION AND LOCALITY.—Upper Cambrian: (310t) Subzone ¢ of the Dictyograptus slate at Fogelséng; (310u)

subzone ¢ of the Dictyograptus slate at Jerrestad; and (310v) subzone 6 of the Dictyograptus slate at Tosterup; all
Westergard, 1909, pp. 57 and 77] in the Province of Malméhus, Sweden.

Genus ACROTHYRA Matthew.¢
[akeoc, at the top; and @vpa, a door.]

Acrothyra MATTHEW, 1901, Bull. Nat. Hist. Soc. New Brunswick, vol. 4, pt. 4, No. 19, pp. 303-304. (Described and
discussed as a new genus.)

. Acrothyra MartHEW, 1902, Trans. Roy. Soc. Canada for 1902, 2d sér., vol. 8, sec. 4, No. 3, p. 104. (Notes on variation

in size, etc., of the different species and varieties of Acrothyra.)

Acrothyra MattHEw, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, pp. 85-86. (Copied from Mat-
thew, 1901b, pp. 303-304.)

Acrothyra MattHEw, 1903, idem, pp. 88-89. (Copied from Matthew, 1901b, p. 304.)

Acrothyra Matthew, Waxcort, 1908, Smithsonian Misc. Coll., vol. 53, No. 4, Pl. XI, and pp. 142 and 146. (Classifica-
tion of genus.)

Ventral valve elongate conical, with the posterior face more or less flattened to form a
false area marked on the median line by a shallow groove. Area unknown. The slope of
the false area is usually backward so as to throw the apex back of the posterior margin, but
in some instances it is directly on a line with the margin. Pedicle opening minute, slightly
truncating the apex. Dorsal valve strongly convex with the beak marginal. Area unknown.

Surface marked by fine, concentric striz and lines of growth and very fine, irregular, con-
centric strize that inosculate so as to give a granulose or pitted surface when seen by a strong
lens. The mner surface of the ventral valve shows fine radiating lines in some specimens. -
The shell is built up of several thin layers or lamelle of a calcareocorneous character. The

a The synonymy for this genus does not give a complete record of the various genera under which the species now included in Acrothyra were
formerly placed; it gives only those references in which the genus is discussed or described. To complete the record the following mere generic
references are listed: Acrotreta Matthew [1899b, p. 203; 1902b, pp. 390 and 391; 1903, pp. 73 and 95].

716 CAMBRIAN BRACHIOPODA.

dorsal valve is usually thicker than the ventral valve, and its mner lamelle are arranged
more oblique to the outer layer.

The cast of the ventral valve indicates a small apical callosity seneimniad by a slender
pedicle tube. The main vascular sinuses are almost straight from the apex far out toward the
anterolateral portion of the valve; im the short valves they diverge quite rapidly, but m the
elongated valves they leave but a narrow space for the visceral area. From the anterior margin
of the apical callosity two narrow ridges extend well forward and then curve outward and inward
to meet about a central depression or pit that occupies the same relative position as the central
depression of the visceral cavity in Obolus and its subgenera. The cardinal scars have not been
observed. The interior of the dorsal valve is strongly concave. A slight median ridge is seen
in some specimens and in others it is very difficult to determine its presence except in the pos-
terior third of the shell, where it is often very strong. On each side of the median ridge there
is usually a rather deep groove in which, at about one-third the distance from the posterior to
the front margins of the valve, the central muscle scars occur; the cardinal scars are clearly
defined on each side of the median ridge near the posterior margin.

Type.—Acrotreta proavia Matthew.

Observations.—This genus is intimately related to Acrotreta and except for the presence in
some species of a well-marked visceral area of a type not known in Acrotreta there would be
difficulty in assigning more than a subgeneric value to it. Matthew [1901b, p. 303] considers
that the mode of occurrence of the ventral valve indicates a difference from Acrotreta, but in the
large collection made by Loper the ventral valve of Acrothyra lies on the long side of the cone,
the aperture being up; this is the position the shell would take in settling down on the bottom
when the animal was out of the shell and the dorsal valve detached. I have found hundreds of
specimens of the ventral valve of Acrotreta idahoensis Walcott and A. attenuata Meek lying on
the upper surface of layers of limestone in situ, in just the same positions as those taken by
Acrothyra proavia (Matthew).

Four species of the genus are known to me: Acrothyra proavia (Matthew), A. signata
Matthew, A. sera (Matthew), and A. minor Walcott. Matthew [1902a, pp. 381-390] has described
a number of varieties of the two Acadian species. -In the case of the varieties of A. proavia I
find that there is such a gradation of form and character between the varieties that they are of
little value. In A. signata the varieties prima and orta are apparently distinctive.

After a thorough comparison of Matthew’s types of Acrothyra signata sera, Acrothyra signata
tarda, Acrotreta papillata and varieties prima and lata, and a large series of specimens from the
same locality and stratigraphic horizon, I have identified the four forms as Acrothyra sera.
There is such a gradation in size and shape of the visceral area and exterior of the ventral valve
that it does not appear practicable to draw lines establishing varieties and species. The gradation
of characters between Matthew’s Acrothyra signata sera and his Acrotreta papillata also practically
brings together Acrothyra and Acrotreta. An attempt is made on Plate LX XX to show some of
the gradations in the form of the visceral area (figs. 6d, 6e, 5a, 6f, 6g, 6h, and 6a).

Matthew [1902a, p. 381] assigns importance to the stratigraphic position of the specimens
he has referred to species and varieties. This does not appear to hold good in the large collec-
tions made by Loper. Most of the varieties in form and robustness occur at the horizon of
Acrothyra sera and those assigned to A. proavia at its horizon. This makes it difficult to give
the same importance to the variations that Matthew [1902a, pp. 381-390] does in his descriptions.
The latter are presented in great detail and should be consulted by those interested in this genus
or in the Acrotretide.

Matthew [1901c, pp. 93-107] has made some most interesting and suggestive observations
on the resemblance of the more elongated forms of Acrothyra to some species of Hyolithes, sugges-
tions to which the student of the Brachiopoda should give careful consideration.

eee

ACROTRETID. el)

AcROTHYRA MINOR Walcott.
Text figure 59; Plate LX XVI, figures 4, 4a-b.
Acrothyra minor Waucott, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 303. (Characterized as below as a new species.)

This species differs from others referred to the genus by its broad form and very strong
vascular smuses. ‘The elevated callus between the simuses is high and oval in outline, some-
what like that of Acrotreta inflata (Matthew). It may be that this species
belongs to a different genus, but with the material available for study it

is referred to Acrothyra on account of its low overhanging false area and
elongate visceral area.

FoRMATION AND LOCALITY.—Middle Cambrian: (5b and 54s) ¢ Dark blue-gray Langston
limestone [Walcott, 1908f, p. 198], just above the Cambrian quartzitic sandstones, north side F

5 e F F FIGURE 59.—Acrothyra minor

of Twomile Canyon, nearits mouth, 2 miles (3.2 km.) southeast of Malade, Oneida County, Walcott. A.A” Exterior

Idaho. and side views of a ven-

“tral valve from Locality
54s, about 2 miles (3.2
km.) southeast of Malade,

s Idak We Ss . Mus.
Plate LXXV, figure 3; Plate LKXVI, figures 3, 3a-u. cee tee nA

ee ACROTHYRA PROAVIA (Matthew).

Acrotreta proavia MarruEw, 1899, Bull. Nat. Hist. Soc. New Brunswick, vol. 4, pt. 3, No. 19, p. 203, Pl. III, figs. 2a-f.
(Described and discussed as a new species.)

Acrothyra proavia prima MatrHEew, 1901, idem, vol. 4, pt. 4, No. 19, figs. 1-6, p. 303. (No mention of this species is
made in the text, which is a description of the genus Acrothyra, but the variety is figured for the first time. The
specimen represented by fig. 1 is redrawn in this monograph, Pl. LX XVI, fig. 3.)

Acrothyra proavia MattHEw, 1902, idem, vol. 4, pt. 5, No. 20, pp. 386-388, Pl. XIV, figs. 2a-¢ and 3a-f. (Described
and discussed. Figs. 2a-f are copied from Matthew, 1899, Pl. III, figs. 2a-f.)

Acrothyra proavia prima MatruEw, 1902, idem, p. 389, Pl. XIV, figs. 4a-f. (Described. Figs. 4a-f are copied from

Matthew, 1901b, figs. 1-6, p. 303.)

Acrothyra proavia crassa MATTHEW, 1902, idem, pp. 389-390, Pl. XIV, figs. 5a-c. (Described and discussed as a new
variety.)

Acrothyra proavia MatruEw, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, pp. 53-55, 57, and 59.
(Notes on orientation of shells.)

Acrothyra proavia prima Marruew, 1903, idem, p. 58. (Notes on orientation of shells. )

Acrothyra proavia prima Martuew, 1993, idem, figs. 1-6, p. 86. (Figs. 1-6 are copied from Matthew, 1901b, figs. 1-6,
p. 303.)

Acrothyra proavia prima MartuEw, 1903, idem, p. 93, Pl. IT, figs. 4a-f. (Text and figures copied from Matthew, 1902a,

p. 389, Pl. XIV, figs. 4a-f.)

Acrothyra proavia crassa MattHEW, 1903, idem, p. 94, Pl. II, figs. 5a-c. (Text and figures copied from Matthew, 1902a,
pp. 389-390, Pl. XIV, figs. 5a-c.)

The generic description is founded on this species and gives all of its principal characters.
Matthew refers to several varieties of this species and [1901b, p. 303, and 1902a, p. 389] names
two of them, prima and crassa. Loper’s collection shows a great variation in the form and out-
line of the valves, particularly the ventral, that appears to include the varieties described by
Matthew. The typical form of A. proavia is illustrated by Plate LX-XVI, figures 3a, 3b, and
3c; the variety prima by figure 3, and the variety crassa by figures 3e and 3f. The gradations
in form between the typical form and its varieties may be traced by the figures on the plate,
and by a study of the large series of specimens in the collections.

The height of the posterior side or false area has been found one-third, one-half, and about
three-fifths of the length of the anterior slope from the apex to the margin. The wide variation
appears to be due very largely to compression and distortion in the sediment.

Acrotreta gemmula Matthew occurs in association with this species, and this leads to confu-
sion of the dorsal valves of the two species unless care be taken to distinguish them. The A.
gemmula shells are rare, and the shell is thinner, which gives less strongly marked interiors, and
less convexity to the outer surface. The dorsal valve of Acrothyra proavia is convex, strong,
and deeply marked by the grooves made by the main vascular sinuses.

25b is the type locality.

718 CAMBRIAN BRACHIOPODA.

Acrothyra proavia differs from A. signata Matthew, which occurs about 200 feet lower in
the strata of the same section, in having usually a narrower, more elongate visceral cavity, and
stronger callosity. These features, however, vary in specimens of A. proavia associated in the
same hand specimen of shale.

FoRMATION AND LOCALITY.—Middle Cambrian: (3i) Compact, fine-grained, thin-bedded gray sandstone of the
Paradoxides zone, on McLean Brook, 1 mile (1.6 km.) east of McCodrum Brook and 1.5 miles (2.4 km.) west of Marion
Bridge; (13m) sandstones of Division H3f of Matthew’s [1903, p. 76] Etcheminian, on Gillis Brook, Indian River;
and (344j [Matthew, 1903, p. 91]) Division Ee of Matthew’s Etcheminian, on the highway at V. McPhees; all in
eastern Cape Breton, Nova Scotia.

(10p) Sandstone just below the waterfall in Dugald Brook, Division E2b; (10q) sandstones a little above 10p in
Division E2b; (18e) sandstones of Division H2c; (181 and 344i [Matthew, 1903, p. 80]) sandy shales of Division E3a;
(18n” and 344b [Matthew, 1903, p. 91]) sandstones of Division E3d; (18n’) sandstones of Division He; (344a | Matthew,
1902b, p. 422]) sandy shales of Division E3c; and (344d [Matthew, 1903, p. 82]) sandy shales of Division H3f; all in Mat-
thew’s [1903, p. 21] Etcheminian, on Dugald Brook, Indian River, eastern Cape Breton, Nova Scotia.

/ ACROTHYRA SERA (Matthew).

Plate LXXX, figures 4, 4a—c, 5, 5a-d, 6, 6a4, 7, 7a-b, 8?.

Acrothyra (signata) sera MatrHEew, 1902, Bull. Nat. Hist. Soc. New Brunswick, vol. 4, pt. 5, No. 20, pp. 383-384, Pl.
XIII, figs. 3a-f. (Described and discussed as a new variety. The specimen represented by fig. 3c is redrawn
in this monograph, Pl. LX XX, fig. 4c.)

Acrothyra signata-tarda MartHEew, 1902, idem, pp. 384-385, Pl. XIV, figs. la-d. (Described and discussed as a new
variety.)

Acrotreta papillata MatTHEW, 1902, idem, pp. 390-391, Pl. XV, figs. 2a-f. (Described asa new species. Inthe descrip-
tion of Pl. XV the legend for figs. la-c appears as the legend for figs. 2a-c, and the legend for figs. 2a-f as the
legend for figs. la-f; the specimens represented by figs. la-c (on the plate) are referred to Acrotreta papillata
prima; and the specimens represented by figs. 2a-f (on the plate) are referred-to Acrotreta papillata. The
description of plate is in error, the correct reference being as given inthissynonymy. The specimen represented
by figs. 2a and 2b is redrawn in this monograph, Pl. LX XX, figs. 6 and 67.

Acrotreta papiliata var. MatrHEw, 1902, idem, p. 391, Pl. XV, figs. 3a-c. (Described. The varietal name lata is
given to this form in the description of Pl. XV.)

Acrotreta papellata-prima MatrHEw, 1902, idem, pp. 391-392, Pl. XV, figs. la-c. (Described and discussed as a new
variety. The third reference explains error in description of plate.)

Acrothyra signata sera MatrHEw, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, p. 56. (Notes on
the orientation of the shells.)

Acrotreta papillata-prima MattHEWw, 1903, idem, pp. 73-74, Pl. III, figs. la-c. (Mentioned as a new variety, but
copies the original text and figures, Matthew, 1902a, pp. 391-392, Pl. XV, figs. la-c. The same error occurs in
the description of Pl. III as occurred in the description of Pl. XV; see the third reference.)

Acrothyra signata sera MattHEw, 1903, idem, pp. 87-88, Pl. I, figs. 3a-f. (Text and figures copied from Matthew, 1902a,
pp. 383-384, Pl. XIII, figs. 3a-f.)

Acrothyra signata-tarda MattHew, 1903, idem, p. 89, Pl. II, figs. la-d. (Textand figures copied from Matthew, 1902a,
pp. 384-385, Pl. XIV, figs. la—d.)

Acrotreta papillata MattHEw, 1903, idem, p. 95, Pl. III, figs. 2a-f. (Text and figures copied from Matthew, 1902a, pp.
390-391, Pl. XV, figs. 2a-f. The same error occurs in the description of Pl. III as occurred in the description
of Pl. XV; see the third reference.)

Acrotreta papillata lata MartHEw, 1903, idem, pp. 95-96, Pl. III, figs. 3a-c. (Text and figures copied from Matthew,
1902a, p. 391, Pl. XV, figs. 3a-c.)

Acrothyra sera differs from A. signata in the form of the visceral area and callosity, straighter
and nearly vertical posterior side. It is usually more elongate. Matthew [1902a, p. 383] placed.
it as a variety of A. signata, but its characters appear to justify giving it the rank of a species.

A gradation in length, breadth, depth, and outline of the ventral valve and its visceral

area is found in specimens from the same bed of rock, that bring together Acrothyra signata sera

and tarda and Acrotreta papillata and its varieties lata and prima. Matthew [1902a, pp. 383-385,
390-392] based the above-mentioned species and varieties on differences in form of the ventral
valve and its visceral cavity and callosity. With his type specimens before me, and the large
series of specimens collected by Loper from Matthew’s Division 1, assise d, and from Division 2,
between assise a and b, it is impossible for me to consider that more than one variable species
is represented. As the name sera is first in order in the original publication, it is retamed for
the species. Also see notes under genus Acrothyra, pages,715-716.

a

ACROTRETIDA. 719

FoRMATION AND LOCALITY.—Middle Cambrian: (10p’) Sandstone 0.25 mile (0.4 km.) from the lower bridge on
Gregwa Brook, Indian River; (10p’”) sandstone on the small brook on the hill between the bridge over Indian River
and McPhees Brook; (18k) shales of Matthew’s [1903, p. 15] Coldbrook, above the great fall in Dugald Brook, Indian
River; and (344e [Matthew, 1903, p. 78]) shales of Division Eld of Matthew’s [1903, pp. 28 and 29] Etcheminian, on
Boundary Brook, eastern side of the Escasonie Indian Reservation; all in eastern Cape Breton.

(344g [ Matthew, 1903, p. 77|) Shales of Division Hic; (18t/’) sandstones of Divisions Ele and E1d; (13£) sandstones
20 feet (6 m.) above Division 2a; (13d’) sandstones opposite the third waterfall in Dugald Brook, between Divisions
E2a and E2b; (10p) sandstones just below the waterfall in Division E2b; and (18e) sandstones of Division E2c; all in
Matthew’s [1903, p. 21] Etcheminian, on Dugald Brook, Indian River, eastern Cape Breton, Nova Scotia.

Shells somewhat doubtfully referred to Acrothyra sera occur at the following localities:

Middle Cambrian: (13p) Sandstones 40 feet (12.2 m.) above Division H2a; and (13p’) sandstones 45 feet (13.6 m.)
above Division E2a; both in Matthew’s [1903, p. 21] Etcheminian, on Dugald Brook, Indian River, eastern Cape
Breton, Nova Scotia.

ACROTHYRA SIGNATA Matthew.
Plate LX XX, figures 1, la-d.

Acrothyra signata MatruEw, 1902, Bull. Nat. Hist. Soc. New Brunswick, vol. 4, pt. 5, No. 20, pp. 381-382, Pl. XIII,
figs. 2a-e. (Described and discussed as a new species, see below for copy of the greater part. The specimens
represented by figs. 2b and 2c are redrawn in this monograph, Pl. LX XX, figs. 1 and 1d, respectively.)

Acrothyra signata MartHEw, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, p. 87, Pl. I, figs. 2a-e.
(Text and figures copied from preceding reference.)

Matthew’s description [1902a, p. 381] of the interior of the two valves is as follows:

There is a strong narrow callus, one-third of the length of the valve, bounded by a raised ridge at the sides and in
front; at the front of this callus is an oval pit, from which a groove runs backward nearly to the apex of the shell, where
it is supposed to connect with the foramen. Outside the callus, on each side, near the margin of the valve, are len-
ticular marks of the lateral muscles. About the middle of the valve the position of the anterior adductors is indicated
by a faint impression of the lozenge or ‘‘heart-shaped” depression. * * *

* * * This shows a sharp, thin, median septum for half of the length of the valve. This ridge is broader and
more distinct at the front; at each side are lateral obscure ridges, diverging from the umbo. Outside of these ridges
are the lenticular imprints of the lateral muscles.

The only modification to be made is in leaving out the word “narrow” before “callus”
in the description of the ventral valve. The callosity is strong and relatively broad.

Among the type specimens received from Doctor Matthew one ventral valve is elongate,
like the type figured by him. Two other ventral valves are shorter, like our figures 1, la-b.
The dorsal valves are similar in the material received from Doctor Matthew and that illustrated
by him, and in the collection made by Mr. 8. Ward Loper.

A. signata differs from A. proavia (Matthew) in the less elongate, narrow visceral cavity
and apical callosity of the ventral valve. It occurs at about 200 feet lower in the strata, accord-
ing to Matthew, who [1903, pp. 23-27] gives a detailed section of the beds and lists of fossils
occurring at each faunal zone.

Matthew [1902a, p. 382] found this species in his Division E1b. Loper collected it from
Matthew’s Division E1d; also in abundance between Divisions E2a and E2b on Dugald Brook.

FoRMATION AND LOCALITY.—Middle Cambrian: (18t) Sandstones at the base of Division Elb; (344k [ Matthew,
1908, p. 77]) sandstones of Division E1b; (13t/’) sandstones of Divisions Ele and Eld; (13d’) sandstones opposite the
third waterfall in Dugald Brook, between Divisions E2a and E2b; (10p) sandstones just below the waterfall in Divi-
sion E2b; all in Matthew’s [1903, p. 21] Etcheminian, Dugald Brook, Indian River, eastern Cape Breton, Nova Scotia.

_~ ACROTHYRA SIGNATA ORTA Matthew.
Plate LX XX, figures 3, 3a-b.

Acrothyra signata orta MatrHEw, 1902, Bull. Nat. Hist. Soc. New Brunswick, vol. 4, pt. 5, No. 20, pp. 385-386, Pl.
XIII, figs. 4a-f. (Described and discussed as a new variety. The specimens represented by figs. 4a and 4c
are redrawn in this monograph, Pl. LX XX, figs. 3a and 3b, respectively.)

Acrothyra signata orta MatrHew, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, pp. 89-90, PI. I,
figs. 4a-f. (Text and figures copied from the preceding reference.) ;

A. signata orta differs from A. signata Matthew im its more elongate form and narrow
visceral area, characters that place the variety near A. proavia (Matthew). Its shorter visceral
area distinguishes it from A. proavia. In the absence of specimens showing the interior of
the ventral valve there is no way of distinguishing A. proavia from A. signata orta.

720 CAMBRIAN BRACHIOPODA.

ForMATION AND LOCALITY.—Middle Cambrian: (13d’’) Sandstones 10 feet (3 m.) below Division E2a; (10p)
sandstones just below the waterfall in Division E2b; and (3441 [ Matthew, 1903, p. 90]) sandstones of Division H2c; all
in Matthew’s [1903, p. 21] Etcheminian, Dugald Brook, Indian River, eastern Cape Breton, Nova Scotia.

\ ACROTHYRA SIGNATA PRIMA Matthew.

Plate LX XX, figures 2, 2a—b.

Acrothyra signata prima MattHEw, 1902, Bull. Nat. Hist. Soc. New Brunswick, vol. 4, pt. 5, No. 20, pp. 382-383, Pl.
XIII, figs. la-g. (Described and discussed as a new variety. The specimens represented by figs. 1b and 1c
are redrawn in this monograph, Pl. LX XX, figs. 2 and 2b, respectively.)

Acrothyra signata prima MartHew, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, p. 73, Pl. I,
figs. la-g. (Text and figures copied from the preceding reference.)

The material representing this shell is in poor condition, but sufficient evidence of the
form and interior characters of the ventral valve is preserved to show that it differs from
A. signata Matthew in its subconical form, and in the shorter and proportionally broader visceral
area. It is very difficult to find any clearly defined distinction between some specimens of
Acrothyra sera Matthew and A. signata prima, as the latter shows ventral valves quite as regu-
larly conical as the former. One of Matthew’s type specimens shows a much higher apex on
the ventral valve than his figure 3c [1903, Pl. I]; another with the apex broken off shows a
cast of the visceral cavity much like that m Plate LX XX, figure la (A. signata Matthew).

Matthew [1902a, p. 383] found the types of this species in a fine gray shale interbedded
in the volcanic beds. The associated fossils clearly indicate that the fauna is essentially the
same as that which follows higher in the strata.

FoRMATION AND LOCALITY.—Middle Cambrian: (13k) 4 Shales of Matthew’s [1903, p. 15] Coldbrook, above the
great waterfall in Dugald Brook, Indian River, Cape Breton, Nova Scotia.

Genus DISCINOPSIS Matthew.)
[Bécxoc, quoit; and dy, face.]

Discinopsis (MattHEw MS.) Hatt and CrarKe, 1892, Eleventh Ann. Rept. State Geologist New York for 1891, pp.
250-251. (Described.)

Discinopsis Matthew, Haut and CrarKe, 1892, Forty-fifth Ann. Rept. New York State Museum for 1891, pp. 566-567-
(Copy of preceding reference.)

_Discinopsis Matthew, Hatt and CrarKe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, pp. 105-106. (De-
scribed and discussed as a new genus.)

Discinopsis Matthew, Watcort, 1908, Smithsonian Misc. Coll., vol. 53, No. 4, Pl. XI, and pp. 142 and 146. (Classifi-
cation of genus.)

All that is known of this genus is incorporated under the description of the type species.
Type.—Acrotreta? gulielmi Matthew.

Lv DIScINOPSIS GULIELMI (Matthew). c

Plate LX XXII, figures 5, 5a-c.

Acrotreta? gulielmi MattHEw, 1886, Trans. Roy. Soc. Canada for 1885, Ist ser., vol. 3, sec. 4, No. 4, pp. 37-39, Pl. V,
figs. 14, l4a-e. (Described and discussed as a new species; see below for copy. The specimen represented by
figs. 14c and 14d is redrawn in this monograph, Pl. LX XXII, fig. 5. Figs. 5a-c of this monograph are drawn
from specimens in the type material, but none of them can be identified with Matthew’s figures.)

Discinopsis gulielmi (Matthew), Hatt and Crarxke, 1892, Eleventh Ann. Rept. State Geologist New York for 1891,
Pl. III, figs. 20 and 21. (Fig. 20 is drawn from the specimen figured by Matthew, 1886, Pl. V, figs. 14c and
14d. Fig. 21 is drawn from one of Matthew’s type specimens, and the same specimen is redrawn in this mono-
graph, Pl. LX XXII, fig. 5a, but the specimen can not be identified with any of Matthew’s figures.)

Discinopsis guhielmi (Matthew), Hatt and CxiarKe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, p. 105,
Pl. III, figs. 20-24. (Discussed. Figs. 20 and 21 are copied from figs. 20 and 21 of the preceding reference.
The remaining figures are drawn from specimens in Matthew’s type material. Figs. 21, 22, and 23 represent

specimens which are redrawn in this monograph, Pl. LX XXII, figs. 5a (= 21 and 22) and 5c (= 28), but it is

impossible to identify the specimens with Matthew’s figures. )
The original description by Matthew follows:

Shell subcircular in outline. Surface depressed-conical, apices eccentric, not marginal. Pedicle valve with
the apex truncated by a circular foraminal aperture (?). The interior of this valve is characterized by a pair of deep,

13k is the type locality, though the specimens represented by that number in the United States National Museum collections were collected
later than the type specimens.
> Prior to the definition of the genus Discinopsis the type species was referred to Acrotreta? [Matthew, 1886, p. 37].

Ee a a

<r TY

ACROTRETID. C21

diverging furrows, passing forward from the beak or internal foraminal opening, in broad curves which converge toward
the anterior margin but without meeting. These furrows inclose a thickened and somewhat elevated central area,
which, in the subumbonal region, is apparently free, projecting for a short distance, like a narrow, triangular shelf,
beneath which the foramen probably opened. The interior opening of the foramen is, however, not apparent on
any of the specimens examined, for, as usually preserved, the matrix has adhered to this subapical cavity, and in
a single example only is the shelf-like character of the median area distinctly demonstrated. A faint longitudinal
ridge passes from the apex of the shelf to the anterior margin, but no other markings are discernible on the interior-
except faint radiating or slightly undulating, probably vascular lines.

The interior of the brachial valve, as far as known, shows no other characters than the radiating lines, which
appear to belong to the ornamentation of the outer surface.

Shell substance tenuous, apparently corneous. External surface covered with more or less prominent, some-
times lamellose concentric growth lines, crossed by fine, gently curved, radiating strizee which are usually more promi-
nent when the concentric lines are exfoliated.

Observations.—The interior of the ventral valve of this species is not unlike that of Acro-
thele. (Compare Pl. LX XXII, fig. 5a, with Pl. LX, figs. 1f and 2.) It is not like that of
_ Acrotreta sagittalis taconica (Pl. LX XI). I have not been able to find an apical shelf in the
type specimens or other specimens. The material representing D. gulielmi is compressed in
the shale, so that the apical callosity is more or less compressed and distorted. The dorsal
valve, with its eccentric apex, is unlike Acrothele or any other of the genera of the Acrotretide.

With our present information, Discinopsis is referred to the Acrotretide and nearest to
Acrothyra.

I have not discussed the description and conclusions of Matthew [1886, p. 37], as neither
Hall and Clarke nor I could find the muscle scars described and illustrated by him. The
student should carefully read Matthew’s description and observations, as there is much oppor-
tunity for difference of opinion of minute shells compressed in shale.

FORMATION AND LOCALITY.—Middle Cambrian: (301g [ Matthew, 1886, p. 39]) Sandstones of Division 1c of Mat-
thew; (308h) shales of Division 1cl; and (801w) shales of Division’ 1c2; all at Portland (now part of the city of St.
John), St. John County, New Brunswick.

Discrnorsis? sutcatus Walcott.
Plate LXX XII, figure 6.

Craniella 2? sp., Watcortt, 1905, Proc. U. 8. Nat. Mus., vol. 29, pp. 4.and 6. (Listed.)

Discinopsis sulcatus Watcort, 1906, idem, vol. 30, pp. 568-569. (Described and discussed as below as a new species.)
This species is based upon the cast of the interior of a small ventral valve that in its

interior markings closely approaches the interior of the ventral valve of Discinopsis gulielmi

(Matthew).

The interior cast shows that the ventral valve was subcircular in outline, moderately
convex, and with the apex probably perforated by a small, circular, foraminal aperture. In
front of the cast of the base of the foraminal aperture there is a broad depression that extends
to the front margin; on each side of the central depression an elongate, slightly depressed
area extends forward and outward from near the base of the cast of the foraminal aperture,
along the ridge on each side of the median depression; back of the base of the foramina) aper-
ture there is a narrow, short, arched furrow that indicates the presence of a corresponding
ridge on the interior of the shell. No other markings are shown on the cast, except the faint
outline of what may have been the visceral area, on the median line in front of the base of
the foraminal aperture and between the broad vascular sinuses.

Observations.—This species is referred to the genus Discinopsis as the result of comparison
with specimens of the interior of a ventral valve of D. gulielmi (Matthew). One interior of
the latter species has scars much like those shown in D.? sulcatus.

This form has a sulcate ventral valve, hence the specific name.

FoRMATION AND LOCALITY.—Upper Cambrian: (C56) Lower part of the Chaumitien limestone, 25 feet below

the top of Pagoda Hill [Blackwelder, 1907a, p. 42 (part of last list of fossils)], 1 mile (1.6 km.) west of Tsinan,
Shantung, China.

62667°—vo1 51, pr 1—12—_46

(22 CAMBRIAN BRACHIOPODA.

Superfamily DISCINACEA Waagen.
Family DISCINID Gray. -
Genus ORBICULOIDEA d’Orbigny.

For synonymy, description, and discussion of this genus the student is referred to the
memoir of Hall and Clarke [1892c, pp. 120-237]. The genus has been recently classified [Wal-
cott, 1908e, Pl. XI, and pp. 142 and 147].

Two Upper Cambrian species are tentatively referred to the genus: O. varzans (Barrande)
and QO. contraria (Barrande), and one Middle Cambrian species, O. pileolus (Salter).

ORBICULOIDEA CONTRARIA (Barrande).
Plate LXXX1I, figure 9.
Discina contraria BARRANDE, 1868, Faune silurienne des environs de Hof, en Baviére, p. 104, fig. 72. (Described
in French as a new species; see below for translation. Fig. 72 is copied in this monograph, Pl. LX X XI, fig. 9.)
Genre? sp. nebulosa BARRANDE, 1868, idem, pp. 105-106, fig. 69. (Described and discussed in French as a new
species. )
Discina contraria BARRANDE, 1868, Neues Jahrb. fiir Mineralogie for 1868, pp. 692-693, unnumbered plate, fig. 72.
(Copied from Beside, 1868a, p. 104, fig. 72.)
Genre? sp. nebulosa BARRANDE, 1868, idem, pp. 693-694, unnumbered plate, fig. 69. (Copied from Barrande, 1868a,
pp. 105-106, fig. 69.)
Discina contraria Barrande, PomprcKs, 1896, Tremadoc Fossilien bei Hof, p. 4. (Occurrence mentioned in German.)

The original description by Barrande follows:

This form, decidedly transverse, contrasts with the preceding, which is elongated. It also forms an ellipse, which,
however, is truncated on the larger side. The shell presents only a slight bulge. The summit is placed somewhat
beyond the center, going toward the truncated edge. Starting from the summit, the surface forms an inclined plane
up to the contour. The perforation is linear and very short. The shell, partly preserved, presents very marked con-
centric striz, at unequal intervals.

Longitudinal diameter, 6 mm.; transverse diameter, 9 mm.

Observations.—Pompeckj [1896a, p. 4] states that this species was found much more
frequently than O. varians (Barrande), and that rather convex shells, 10 mm. long and 12 mm.
broad, were not rare.

The generic relation of this species is doubtful. It is not Discina, nor from the evidence
available can it be referred without question to Orbiculoidea.

Pompeckj, in reply to my inquiry as to whether he had identified ‘ ‘Genre! nebulosa”’ of

Barrande, wrote as follows under date of August 7, 1906:

As to the nebulosa by Barrande (Faune silurienne des Environs de Hof, fig. 69) I find in notes made on the Barrande
originals (in the collection of the Oberbergamt-Munich) that “nebulosa” is to be identified with Barrande’s Discina
contraria, 1. c., figure 72. Both are pedicle valves of Discina with the characteristic perforation of that family below
the apex. Both figures are incorrectly given. The two sharp lines radiating from the apex in figure 69 are only caused
by pressure of the somewhat high shell, and in figure 72 the concentric strize are indeed much more delicate than in
the figures which represent an interior cast only, with bits of the shell in the upper part, i. e., near the hinge line.

Exact determination of these shells is very difficult; most of them (I saw more than a hundred) are compressed,
crumpled, deformed, very seldom the apical region is clearly to be seen; shell rarely preserved; but there is indeed no
doubt that they must belong to the Discinidz on account of the ‘‘Schlitz” below the apex. There is no sharp differ-
ence between the rounded form, named Discina varians by Barrande, and between the larger and wider form, D.
contraria, or nebulosa.

FoRMATION AND LOCALITY.—Passage beds between the Upper Cambrian and the Ordovician: (303e [Barrande,
1868a, p. 104]) suburbs of Hof; and (303% [Pompeckj, 1896a, pp. 7 and 8]) railway cut near Schellenberg, a little distance
back of the railway station at Neuhof, near Hof; both in Bavaria, Germany.

ORBICULOIDEA PILEOLUS (Hicks MS.) (Salter).

Plate LXXX1, figures 11, lla.

Discina pileolus (Hicks MS.) Saurmr, 1866, Rept. British Assoc. Adv. Sci. for 1865, p. 285. (Mentioned.)

Discina pileolus Salter, Davipson, 1868, Geol. Mag., vol. 5, pp. 312-313, Pl. XVI, figs. 11-12. (Described and dis-
cussed; see p. 723 for copy of description. Figs. lla and 12a are copied in this monograph, Pl. LXXXI,
figs. 11 and 11a, respectively.)

—

DISCINIDA. (233

Discina pileolus Salter, Davipson, 1871, British Fossil Brachiopoda, vol. 3, pt. 7, No. 4, p. 344, Pl. XLIX, figs. 41-42.
(Original dascaveon, Darien, 1868, pp. 312-3138, copied. Figs. 41 and 42 are aenredl a Davidson, Pl. XVI,
figs. 12 and 11, respectively.)

Not Discina pileolus? Hicks, 1871, Quart. Jour. Geol: Soc. London, vol. 27, pt. 1, Pl. XV, figs. 12 and 12a. (Referred
in this monograph to Stenotheca.)

Orbiculoidea pileolus (Salter), Hatuand CLarKe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, p. 137. (Changes
generic reference.) ss ‘

The original description by Davidson [1868, p. 312], follows:

Shell very small, circular or slightly longitudinal oval, rather broader anteriorly; about two and a half lines in
length and a little less in breadth. Dorsal valve conical. Ventral valve slightly convex, depressed near the margin;
vertex in both valves at a short distance from the center, as also the foramen (?) in the ventral valve. Surface marked
with concentric lines, which are more strongly marked in the ventral valve. Interior not known.

I have not been able to secure specimens of this interesting shell, so can not add any per-
sonal observations upon it. Hall and Clarke [1892c, p. 137] suggest its reference to Orbiculoidea
and in this, from our present information, I concur. As they have pointed out, it is the oldest
representative of the genus.

Hicks [1871, Pl. XV, fig. 12] illustrates a depressed conical shell from the ‘‘Red”’ beds at the
base of the “‘ Purple” rocks, about 3,000 feet below the base of the Middle Cambrian ‘‘ Menevian
group” as ““Discina pileolus.” Later [1881, p. 297] he calls the species ‘“Discina cerfaiensis.”’
To me the shell is more suggestive of the gastropod genus Stenotheca than of a brachiopod
and until I can obtain better material it will be so referred.

FoRMATION AND LOCALITY.—Middle Cambrian: (318e) Lower portion of the Menevian at Camlan, North Wales;
(318d) sandstones im the middle portion of the Menevian at Porth-y-rhaw, St. Davids, South Wales; (318p) sandstones
in the middle portion of the Menevian at Ninewells, near St. Davids, South Wales; (318q) yellowish-gray beds in the
Harlech group, on the road between Solva and Whitechurch, St. Davids, South Wales; and (318r) sandstones in the
middle portion of the Menevian at Solva Harbor, St. Davids, South Wales; all [Davidson, 1871, pp. 344 and 345] in
Wales.

ORBICULOIDEA VARIANS (Barrande).
Plate LXXXI, figure 8.

Discina varians BARRANDE, 1868, Faune silurienne des environs de Hof, en Baviére, pp. 103-104, fig. 71. (De.
scribed in French as a new species. Fig. 71 is copied in this monograph, Pl. LXXX1, fig. 8.)

Discina varians BARRANDE, 1868, Neues Jahrb. fiir Mineralogie for 1868, p. 692, unnumbered plate, fig. 71. (Copy
of preceding reference.)

Discina varians Barrande, Pomprcxs, 1896, Tremadoc Fossilien bei Hof, p. 4. (Occurrence mentioned in German.)

The original description by Barrande follows:

The form of this species is always elongated, but in proportions varying somewhat with the individuals. The
- surface is slightly arched. The summit is somewhat beyond the center of the figure, which is an ellipse, slightly
truncated at the small end near the perforation. The perforation is linear and less than 1 mm. in length. The frag-
ments of the shell that remain present traces of fine concentric strie. The imperforate valve has not been observed.
Length, 6 mm.; breadth, 5 mm.

Observations.—I am not able to add to the above description. It is evident that the species
is not a Discina, as that genus is now understood, but with only a single figure and the above
description it is not practicable to make a satisfactory generic reference. The subcentral apex
with the elongate slit back of it, is more suggestive of Orbiculoidea than any other genus of the
lower Paleozoic fauna.

FORMATION AND LOCALITY.—Passage beds between the Upper Cambrian and the Ordovician: (308¢ [Barrande,

1868a, p. 103]) suburbs of Hof; and (303f [Pompeckj, 1896a, pp. 7 and 8]) railway cut near Schellenberg, a little distance
back of the railway station at Neuhof, near Hof; both in Bavaria, Germany.

724 CAMBRIAN BRACHIOPODA.
Superfamily CRANIACEHA Waagen.

Family CRANIID4 King.
Genus PHILHEDRA Koken.¢

Philhedra KoxEn, 1889, Neues Jahrb. fiir Mineralogie, Beilage-Band 6, Hit. 3, p. 465. (Discussed in German as a
new genus.)

Phithedra Koken, von HuENg, 1899, Neues Jahrb. fiir Mineralogie, Bd. 1, pp. 146-147. (Described and discussed in
German. See below for translation of diagnosis.)

Philhedra Koken, von HuEne, 1899, Verhandl. Russ.-kais. min. Gesell. St. Petersburg, 2d ser., Bd. 36, Lief. 2, pp.
216-218 (list of species referred to Philhedra), and pp. 297-298. (Described and discussed in German.)

Philhedra Koken, Waucort, 1908, Smithsonian Misc. Coll., vol. 53, No. 4, Pl. XI, and pp. 142 and 147. (Classification

of genus.)
The emended diagnosis of the species by von Huene follows:

Inequivalve, with the flat ventral shell attached. Dorsal shell subconical to bowl-shaped, frequently irregularly
bent; the concentric growth lines are mostly crossed by radial ribs or rows of prickles; without limbus. Anterior
occlusors larger than posterior occlusors.

Type.—Patella rwulosa Kutorga.

Von Huene, in his memoir on the Silurian Crantide [1899b, pp. 181-359], redefines the genus
Phithedra of Koken, and considers P. columbiana (Walcott) as its oldest representative. The
student who wishes to pursue the study further should read von Huene’s memoir on the Silurian
Craniide [1899b, pp. 181-359] and his “‘Systematik der Craniaden”’ [1899a, pp. 138-151].

PHILHEDRA COLUMBIANA (Walcott).
Plate LXXX1I, figure 10.

Crania? columbiana Waucortt, 1889, Proc. U. S. Nat. Mus. for 1888, vol. 11, p. 441. (Described and discussed as a
new species.)

Crania? columbiana Walcott, von Hurene, 1899, Neues Jahrb. fiir Mineralogie, Bd. 1, p. 141, footnote. (Mentioned.)

Philhedra? columbiana (Walcott), von Hurne, 1899, Verhandl. Russ.-kais. min. Gesell. St. Petersburg, 2d ser., Bd. 36,

Lief. 2, pp. 216 and 298. (Mentioned.)

Crania columbiana Walcott, MatrHEW, 1902, Trans. Roy. Soc. Canada for 1902, 2d ser., vol. 8, sec. 4, No. 3, pp. 108-109.

(Copies the original description, Walcott, 1889c, p. 441.)

Philhedra columbiana Waxcort, 1908, Canadian Alpine Journ., vol. 1, No. 2, Pl. I, figs.5 and 5a. (No text reference.

Figs. 5 and 5a are copied in this monograph, Pl. LX X XI, figs. 10 and 10’, respectively.)

Shell small, subcircular, or a little longer than wide, subconical with the apex slightly
eccentric. Outer surface exfoliated; the mner layer of the shell appears to have been com-
posed of a calcareocorneous substance; it is marked by from 40 to 45 fine ribs that radiate
from the apex to the margin. Diameter about 2 mm. When preparing this monograph I
carefully examined the original specimen, removed a little of the attached matrix from the
outer margins and discovered traces of what appear to be minute spines radiating from the
margin.

Many collections from the type locality of this species have passed through my hands
from 1888 to 1906, but it was not until the summer of 1907 that another specimen was seen,
and then only two were found in the Ogygopsis zone of Mount Stephen. These are both crushed
and broken specimens of the inner side of the conical valve. There is a striking similarity
in appearance between this shell and Crama lelia Hall and Clarke [1892c, Pl. IV u, fig. 1] and
other similar forms.

The specific name is derived from British Columbia.

ForMATION AND LOCALITY.—Middle Cambrian: (14s) About 2,300 feet (701 ™m.) above the Lower Cambrian and

2,700 feet (823 m.) below the Upper Cambrian, in the Ogygopsis zone of the Stephen formation [Walcott, 1908f, p. 210],
on the northwest slope of Mount Stephen, above Field on the Canadian Pacific Railway, British Columbia, Canada.

a The synonymy for this genus is not complete and does not even give a record of all the genera under which the Cambrian species of Philhedra
has been placed; it gives only those references in which the genus is discussed or described. To complete the record for the species taken up in
this monograph the following mere references are listed:

Crania? Walcott [1889c, p. 441]. Crania Matthew [1902c, p. 108].
Crania? yon Tuene [1899a, p. 141].

ey Oe

a

te

BILLINGSELLIDA. 725

Order PROTREMATA Beecher.

[zed, early; and tonya, perforation.]

Superfamily ORTHACEA Walcott and Schuchert.
Family BILLINGSELLID Schuchert.
Subfamily NISUSIIN4 Walcott and Schuchert.

Genus NISUSIA Walcott.

Billingsella Hawn and Crarke (in part), 1892, Nat. Hist. New York, Paleontology, vol.8, pp. 230-231. (Described
and discussed as a new genus. As described the genus includes species that are now referred to Nisusia.)

Nisusia Waucort, 1905, Proc. U. 8. Nat. Mus., vol. 28, pp. 247-248. (Described essentially as below as a new genus.)

Nisusia Walcott, GRaABAU and Sumer, 1907, North American Index Fossils, vol. 1, p. 210. (Characterized.)

Nisusia Watcort, 1908, Smithsonian Misc. Coll., vol. 53, No. 4, Pl. XI, and pp. 142 and 147. (Classification of genus.)

Form subquadrate to transversely semioval. Shell structure dense with a minutely
granular groundmass with minute pores penetrating some of the lamelle forming the shell.
The pores vary greatly in number and arrangement. Surface with narrow, radiating ribs
that support irregularly distributed spines on their crests.

Ventral valve elevated and usually much more convex than the dorsal, and in most species
a mesial sinus appears on it. Area high, vertical or inclined backward; delthyrium large and
partly closed with a convex deltidium; teeth strong and supported by dental plates that
extend outward, also inward, forming on the inside a shallow spondylium. Dorsal valve
moderately convex with only a trace of a median elevation; usually the surface is convex, but
it may be slightly concave from the umbo to the margins; crura well developed, with the crural
plates extended so as to form a shallow cruralium. No traces of a cardinal process have been
observed in the dorsal valve.

Type.—Orthisina festinata Billings.

Observations.—A. comparison of the area of the ventral valve of Misusia with that of the

‘same valve in Billingsella shows in each a convex deltidium partly covering a large trian-
gular delthyrium. In Billingsella the upper extremity of the deltidium is perforate and it
is probably so in Msusia, but on this point there is an uncertainty, as no specimen has been
found clearly showing the pedicle opening. It may be that the deltidium of Misusia was per-
forate in the younger stages of growth and subsequently filled by shell growth. The strong
vascular sinuses of the ventral valve of Billingsella are absent in Nisusia, as well as the tripartite
division of the umbonal cavity. The interiors of the dorsal valves of the two genera show
marked differences. The cardinal process is well developed in Billingsella but not in Misusia.
There is a small, shallow cruralium in Msusia but none in Billingsella. The dorsal valve of
Nisusia has a clearly developed cruralium, but not any trace of a cardinal process. The ventral
valve of Billingsella shows a tendency to form a spondylium resting on the interior of the
valve, a character unknown in Misusia.

The general form of Nisusia is not unlike that of Billingsella except that its ventral valve
has a more erect beak and cardinal area. These comparisons include such species of Billingsella
as B. coloradoensis, B. plicatella, and B. exporrecta, but not B. dice (Pl. Cl, figs. 8, Sa-c). Of
Nisusia, they include N. festinata and some of the subgenus Jamesella, such as NV. (J.) perpasta,
erecta, and ami.

Billingsella and Nisusia both occur in Lower Cambrian strata, but Billingsella has its
greatest development in the Middle Cambrian and Nisusia in the Lower Cambrian. It is not

a The synonymy for this genus does not give a complete record of the various genera under which the species now included in Nisusia were
formerly placed; it gives only those references in which the genus is discussed or described. To complete the record the following mere generic

references are listed:

Orthisina de Verneuil and Barrande [1860, p. 533]. Orthisina Walcott [1886b, pp. 120 and 121; 1889c,
Orthisina Billings [1861b, p. 10; 1861c, p. 949; 1862b, p. 442; 1891a, p. 613].

p. 105; 1862e, p. 221; 1863, p. 284]. Orthisina Tate [1892, p. 185].
Orthisina Mallada [1875, p. 32]. Billingsella Schuchert (1897, p. 158].

Orthisina Matthew [1902c, p. 109].

(26 CAMBRIAN BRACHIOPODA.

probable that either genus is directly descendant from the other, but I think that both came
from an ancestor that lived in early Lower Cambrian time and that Billingsella is further
advanced in its development than Nisusia.

Nisusia ALBERTA (Walcott).
Plate C, figures 3, 3a-d.

Orthisina alberta Waucott, 1889, Proc. U. S. Nat. Mus., vol. 11, p. 442. (Described as a new species.)

Billingsella alberta (Walcott), ScxucHErt, 1897, Bull. U. 8. Geol. Survey No. 87, p. 158. (Merely changes generic
reference.)

Orthisina alberta Walcott, MarrHrw, 1902, Trans. Roy. Soc. Canada, 2d ser., vol. 8, sec. 4, No. 3, p. 109. (Original
description, Walcott, 1889c, p. 442, copied.)

Nisusia alberta Waucotr, 1905, Proc. U. S. Nat. Mus., vol. 28, pp. 248-249. (Described and discussed essentially

as below. .

Nisusia alberta Hoel 1908, Canadian Alpine Jour., vol. 1, No. 2, p. 245, Pl. I, figs. 4 and 4a. (No text reference.

Figs. 4 and 4a are copied in this monograph, Pl. C, figs. 3c and 3d, respectively.)

Shell transversely suboval, front broadly rounded; the straight hinge line is shorter than
the full width of the valves. Surface of shell with numerous radiating ribs that increase by
interpolation; on a shell 19 mm. in width there are four ribs near the front margin in a dis-
tance of 3 mm.; the ribs are rather narrow and sharp crested, the interspaces being wider than
the ribs. A cast of the outer surface of a shell in siliceous shales shows numerous strong spines
irregularly distributed on the ribs very much as in N. festinata (Pl. ©, fig. 3c).

Ventral valve elevated at the umbo and apex in some shells, convex and rounded over
toward the area in others; area varying in height in different shells, usually elevated and
overhanging the hinge line; it is divided by a strong delthyrium that is covered by a convex
deltidium of varying length, arched at its front margin and divided by longitudinal lines into
three parts.

Dorsal valve gently convex; area low, and a little inclined over the hinge line; delthyrium
broad with a narrow chilidium. Casts of the interior show a broad, well-defined pseudo-
cruralium and just in advance of it the adductor muscle scars.

Observations.—This species recalls at once Nisusia festinata by its elevated ventral valve
and spinose surface; it differs from it by its transversely suboval outline, large umbonal muscle
cavity (pseudocruralium) in the dorsal valve and sharp crested ribs. Nisusia (Jamesella)
perpasta has the general form and surface characters of this species. A marked difference is
caused by JN. alberta occurring in a siliceous shaly matrix and NV. (Jamesella) perpasta as casts
in a quartzitic sandstone, and the strong surface spines of NV. alberta are sparingly represented
on the latter. A shell that appears to be identical with this species occurs at about 1,600
feet above the base of the Middle Cambrian terrane in Utah. -

The specific name is derived from Alberta, Canada.

ForMATION AND LOCALITY.—Middle Cambrian: (14s) About 2,300 feet (701 m.) above the Lower Cambrian and
2,700 feet (823 m.) below the Upper Cambrian in the Ogygopsis zone of the Stephen formation [ Walcott, 1908f, p. 210], at
the ‘‘fossil bed,”’ on the northwest slope of Mount Stephen; and (35k) Burgess shale member of the Stephen formation on
the west slope of the ridge between Mount Field and Wapta Peak, 1 mile (1.6 km.) northeast of Burgess Pass; both
above Field on the Canadian Pacific Railway, British Columbia, Canada.

Specimens that probably belong with Misusia alberta occur at the following locality,
together with other specimens that are somewhat doubtfully referred to the species:

Middle Cambrian: (54q) A drift block supposed to have come irom a horizon 1,700 feet (518.2 m.)above the
Brigham quartzite [Walcott, 1908a, p. 8], found near the mouth of Wasatch Canyon, east of Lakeview ranch, 5 miles
(8 km.) north of Brigham, Boxelder County, Utah.

Specimens that appear to represent a variety of Mswsia alberta occur at the following
localities:

Middle Cambrian: (57¢ and 57k) About 2,500 feet (762 m.) above the Lower Cambrian and 2,475 feet (754 m.)

below the Upper Cambrian in the limestone forming 1 of the Stephen formation [Walcott, 1908f, p. 209]; and (58z)
about 1,875 feet (572 m.) above the Lower Cambrian and 3,100 feet (945 m.) below the Upper Cambrian in the lime-

BILLINGSELLID. 127

stone forming 2b of the Stephen formation [Walcott, 1908f, p. 211]; both on Mount Bosworth, north of the Canadian
Pacific Railway between Hector and Stephen, on the Continental Divide between British Columbia and Alberta,
Canada.

(57j) About 2,000 feet (609.6 m.) above the Lower Cambrian in the limestone forming 2 of the Stephen formation
[Walcott, 1908c, p. 237 (6)], just east of the “‘fossil bed,” on the northwest slope of Mount Stephen, above Field on
the Canadian Pacific Railway, British Columbia, Canada.

Lower Cambrian: (58k) Just below the Middle Cambrian in the limestone forming 1 of the Mount Whyte forma-
tion [Walcott, 1908c, p. 240 (9)], just above the tunnel; and (58p) drift block of limestone believed to have come from
the limestone forming 1 of the Mount Whyte formation [Walcott, 1908c, p. 240 (9)], found near the Canadian Pacific
Railway track just west of the tunnel; both 3 miles (4.8 km.) east of Field, British Columbia, Canada.

Nisusia compra (Tate).
Plate XOVII, figure 14.

Orthisina compta Tats, 1892, Trans. Roy. Soc. South Australia, vol. 15, p. 185, Pl. II, figs. 6 and 6a. (Described as
anew species. The specimen represented by figs. 6 and 6a is redrawn in this monograph, Pl. XOVII, fic. 14.)

Form transversely subquadrilateral with the hinge line a little shorter than the greatest
width of the shell. Surface of the shell marked by strong, concentric ridges of growth that
cause undulations of variable extent, also fine radiating, rounded, depressed ribs that are a
little wider than the interstitial furrows. The outer surface is exfoliated, but the interior
lamellz of the shell show small, irregularly distributed nodes on the ribs that are considered
to be the bases of spines similar to those on the surface of Nisusia festinata (Billings) (Pl. C,
fig. 1) and WN. alberta (Walcott) (PI. C, fig. 3c).

The ventral valve is moderately convex with a low median fold. Area of medium width
and projecting slightly backward; it is divided midway by a rather broad, triangular delthyrium
that is nearly covered by a convex deltidium; the area and delthyrium are marked by fine
transverse lines of growth.

Length of valve from beak to incurve of median fold, 6 mm.; greatest width, 9 mm.;
length of hinge line, 7 mm.

Observations.—This species is represented in the collection before me by a single speci-
men. ‘This appears to be a ventral valve, but, unlike the ventral valve of UN. festinata (Pl. C,
figs. 1, la-d), which has a median sinus, it has a median fold. The area and convex deltidium
are like those of the ventral valve of NV. festinata. The fine ribs and quadrate form distinguish
this species from other species of the genus.

FORMATION AND LOCALITY.—Middle? Cambrian: (315 [Tate, 1892, p. 185]) Limestone at Curramulka, Yorke
Peninsula, South Australia.
NISUSIA FESTINATA (Billings).

Text figure 6, page 299; Plate C, figures 1, la-j, 2, 2a-c.

Orthisina festinata Br1ines, 1861, Geol. Survey Canada, Paleozoic Fossils, vol. 1, p. 10, figs. 11 and 12. (Described
as a new species.)

Orthisina festinata Brruines, 1861, Report on the Geology of Vermont, vol. 2, p. 949, figs. 350-352. (Text and figures
copied from preceding reference.). 2

Orthisina festinata Brurnes, 1862, Am. Jour. Sci., 2d ser., vol. 33, p. 105. (Discussed.)

Orthisina festinata BrxuiNGs, 1862, Report on the Economic Geology of Vermont, by Hager, p. 221, figs. 350-352. (Text
and figures copied from Billings, 1861b, p. 10, figs. 11 and 12.)

Ortilusina festinata Brutines, 1863, Geol. Survey Canada, Fifteenth Rept. Progress, figs. 289a-c, p. 284. (No text
reference. The figures are copied from Billings, 1861b, figs. 11 and 12, p. 10.) ~

Oriusina festinata Billings, Waxcorr, 1886, Bull. U. 8. Geol. Survey No. 30, pp. 120-121, Pl. VII, figs. 7, 7a-b.
(Original description, Billings, 1861b, p. 10, copied. The two specimens represented by figs. 7 and 7a-b are
redrawn in this monograph, Pl. C, figs. 1a and 1h, respectively.)

Orthisina festinata Billings, Watcorr, 1891, Tenth Ann. Rept. U. S. Geol. Survey, p. 613, Pl. LX XII, figs. 7, 7a-b.
(Mentioned. The figures are copied from the preceding reference.)

Bullingsella festinata (Billings), Haun and CuarKe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, p. 230.
(Merely changes generic reference.)

~ Msusia festinata (Billings), Watcorr, 1905, Proc. U. S. Nat. Mus., vol. 28, pp. 249-251. (Described and discussed

essentially as on p. 728.)

Nisusia festinata (Billings), GRaBau and Sumer, 1907, North American Index Fossils, vol. 1, p. 211, fig. 249, p. 210.
(Described. Fig. 249 is copied from Walcott, 1886b, Pl. VII, figs. 7, 7a-b.)

128 CAMBRIAN BRACHIOPODA.

General form subquadrate to transversely semioval, with the cardinal extremities subacute
to obtusely angular. Hinge line straight, usually equal to or greater in length than the width
of the body of the shell. Shell substance dense, granular, with minute pores arranged in scat-
tered radiatimg lines; none of the pores appear to pass through more than one lamella of the
shell.

Surface with narrow, rounded, radiating ribs, that crease by both bifurcation and inter-
polation; the ribs are roughened by concentric lines and ridges of growth that -arch about the
base of strong, acute spines; the spines are located on the ribs, usually just back of a ridge of
growth; they are in more or less irregular, concentric rows toward the front of the shell, but
on the central portions they may be scattered without any system of arrangement; each spine
is larger at the base, tapering rapidly, and curving gradually backward at about one-half its
length.

The ventral valve is more or less elevated at the umbo and apex; in some examples it is
subpyramidal (Pl. C, fig. le), where the height is to the length as 3 to 6, and width 9 mm.; in
other shells the proportion is 4 to 11, and width 17 mm.; the slopes from the apex to the mar-
gins are nearly straight or slightly convex; the form of the umbo and apex varies from a broad,
rounded umbo terminating in a minute beak curving over the area, to an erect, vertical, more
or less rounded apex, with a broad base rising abruptly from the elevated umbo; a shallow,
rounded, median sinus occurs on most shells, but it is sometimes absent. Area high, and crossed
by transverse lines of growth; it is usually inclined over the hinge line, but it may be vertical
or inchned forward (fig. le); it is divided by a strong delthyrium, which is covered by a convex
deltidium that the author of the species, Billings, describes [1861c, p. 10] as perforate at the
apex.? I have not been able to verify this in a large collection of material from various local-
ities; casts of the interior of the extended beak indicate but do not prove that there was a
perforation; the front edge of the deltidium is arched so as to leave a space of variable height
between it and the plane of the hinge line; in three examples the area is divided into three —
parts by longitudinal lines (PI. C, fig. le’’), two of the lines bound the delthyrium, and one
on each side corresponds in position to the ‘‘flexure” lines in Obolus and Hipparionyx. A
cast of the interior of a low ventral valve (PI. C, fig. 1f’) shows a broad delthyrium, strong teeth,
and supporting dental plates which are produced on the inside so as to form a short, elevated
base (pseudospondylum), and on the outside the plates are continued partly about the space
occupied by the points of attachment of the diductor muscles.

The dorsal valve is moderately convex at the umbo, sloping gently from there to the
margins; usually the slope is convex, but in.one example it is slightly concave; area narrow
and vertical or slightly inclined over the hinge line; casts of the interior show the crura, points
of attachment of posterior adductor scars (e, Pl. C, fig. 1g; see fic. 3a), area of attachment of
diductor scars (d’, Pl. C, figs. 1g, 11). Vascular and ovarian markings unknown.

Observations.—This shell has a wide geographic distribution. I have collected it at the
type locality in the township of Georgia, Vermont; at Bic on the lower St. Lawrence River; and
near York, Pennsylvania. The matrix at Bic is a finely granular, slightly arenaceous lime-
stone in which the outer form of the shell is well preserved, but the spines are rarely seen. At
Swanton and Georgia, Vermont, the shell occurs in siliceous limestone and arenaceous shale,
and a cast of the outer surface shows the spines; the material from the finely arenaceous lime-
stone at the Emigsville localities, discovered by A. Wanner, of York, Pennsylvania, is the best
preserved and affords excellent casts of the interior and exterior of the valves. In all of the
localities the variation in the form and elevation of the ventral valve occurs; specimens of the
ventral valve from Bic, Canada, show a shorter deltidium than is usually present. A number
of exfoliated shells occur in the collection from the dark-gray compact limestones of eastern
New York and are doubtfully referred to this species.

a Through the courtesy of Dr. J. F. Whiteaves, of the Geological Survey of Canada, I had the opportunity of examining the types of “‘Orthisina
festinata.” None of them preserve the apex of the deltidium, so it is impossible to determine upon what Billings based his statement that the
deltidium was perforate.

BILLINGSELLIDA. (29

Nisusia festinata is a strongly marked species that appears to have but one near repre-
sentative in form, N. (Jamesella) perpasta. It differs from the latter species in the absence of
spines and in the form of the ventral valve.

FORMATION AND LOCALITY.—Lower Cambrian: (392a) Limestones at L’Anse au Loup, on the north shore of the
Straits of Belleisle, Labrador.

(20) Limestone bowlders in conglomerate, on shore at east entrance to harbor at Bic, Rimouski County, Quebec,
Canada.

(25a) Limestone on the Hall (Donaldson’s) farm, 2 miles (3.2 km.) east of Swanton; (319e [Billings, 1861b, p. 10])
limestone 2 miles (3.2 km.) east of Swanton; (25) sandstone just above Parker’s quarry, near Georgia; (319m) shales of
No. 6 of the section at Parker’s quarry [Walcott, 1891b, p. 278], near Georgia; (26) sandstone northeast of the Corman
farm buildings, east of Highgate Springs; and (392p) shale on the Jewell farm; all in Franklin County, Vermont.

(319w) Limestone 1.25 miles (2 km.) north of Rutland, Rutland County, Vermont.

(38a) Limestone 2 miles (3.2 km.) south of North Granville, on the road which turns south from the road running
between that village and Truthville, 4 miles (6.4 km.) west-northwest of Granville, Fort Ann quadrangle (U.S. Geol.
Survey); and (36) limestone 1 mile (1.6 km.) south of Shushan and 3.5 miles (5.6 km.) north-northeast of Cambridge,
Cambridge quadrangle (U. S. Geol. Survey); both in Washington County, New York.

(49) Sandstone on Codorus Creek, 0.125 mile (0.2 km.) below Meyer’s mill, near Emigsville; (49a) sandstone
on the Liverpool road, south of the schoolhouse, 3 miles (4.8 km.) northwest of York; (346c) shale near York; and
(49w) limestone in railroad cut 0.25 mile (0.4 km.) south of Emigsville; all in York County, Pennsylvania.

(35f) About 300 feet (91 m.) below the Middle Cambrian in the limestone forming 6 of the Mount Whyte formation
[Walcott, 1908c, p. 242 (11)] just above the tunnel on the north shoulder of Mount Stephen, about 3 miles (4.8 km.)
east of Field, British Columbia, Canada.

(35h) About 375 feet (114 m.) below the Middle Cambrian in the shales of No. 4 of the Mount Whyte formation
[Walcott, 1908f, p. 214], on Mount Bosworth, north of the Canadian Pacific Railway between Hector and Stephen,
on the Continental Divide between British Columbia and Alberta, Canada.

NISUSIA FESTINATA TRANSVERSA (Walcott).

eZ
Plate C, figures 4, 4a-b.

Orthisina ? transversa Waucort, 1886, Bull. U. S. Geol. Survey No. 30, p. 121, Pl. VII, figs. 5 and 5a. (Described as
below as a new species. The specimens represented by figs. 5 and 5a are redrawn in this monograph, Pl. C,
figs. 4 and 4a, respectively.)

Orthisina ? transversa Waucort, 1891, Tenth Ann. Rept. U. S. Geol. Survey, p. 613, Pl. LX XII, figs. 9 and 9a. (No
text reference. Figs. 9 and 9a are copied from figs. 5 and 5a, respectively, of the preceding reference.)
Nisusia festinata transversa Waucotr, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 251. (Original description copied as

below and species placed as variety of Nisusia festinata.) :

Shell small, transversely subquadrangular in outline, front broadly rounded, angle formed
by the union of the cardinal slopes of the ventral valve 155° to 165°, hinge line straight and
as long as the width of the shell. Area of the ventral valve of moderate height, bent back
from the hinge line, divided by a triangular foramen that is higher than wide and covered by
a convex deltidium; the area of the dorsal valve is bent back at more than right angles to the
hinge line; foramen higher than wide, covered by a deltidium.

Surface marked by numerous radiating, fine, even cost, eight in a distance of 3 mm. on
the frontal margin of the ventral valve; a few concentric lines of growth cross the radiating
costz, but not so as to give them a nodose character.

Interior characters unknown. ‘The fine radiating strize and transverse form distinguish
this from other described species known to me.

FoRMAT.ON AND LOCALITY.—Lower Cambrian: (25) Sandstone just above Parker’s quarry, near Georgia; (319m)
shales of No. 6 of the section at Parker’s quarry [Walcott, 1891b, p. 278], near Georgia; and (25a) limestone on the Hall

(Donaldson’s) farm, 2 miles (3.2 km.) east of Swanton; both in Franklin County, Vermont.

Nisusta RARA Walcott.

Text figure 60, page 730.

Nisusia rara Watcort (in part), 1908, Smithsonian Misc. Coll., vol. 53, No. 3, p. 97, Pl. IX, fig. 13a (not fig. 13, which
represents a specimen of Hoorthis thyone). (Characterized and discussed as below as a new species. Fig. 13a
is copied in this monograph as fig. 60,p. 730.)
The ventral valve of this species has the same general form as that of Nisusia festinata
(Billings) (PI. C, figs. 1d and le) except that it has a very strong and deep median sinus and

ao CAMBRIAN BRACHIOPODA.

‘

is more transverse; the delthyrium is also larger. Nisusia rara occurs at the same stratigraphic

horizon as Nisusia alberta (Walcott), but it differs from the latter in having a larger delthyrium
and a strong and deep median sinus. "

The surface of NV. rara is marked by rounded radiating ribs that increase by interpolation

and bifurcation; small nodes on some of the ribs indicate the presence of spines on the outer

surface. A portion of a convex deltidium is shown that has the outer portion broken away.

The type specimen has a length of 8 mm.; width, 16 mm.

FoRMATION AND LOCALITY.—Middle Cambrian: (55c) Spence shale member of the Ute limestone [Walcott, 1908a,

p. 8], about 50 feet (15.2 m.) above the Brigham quartzite and 2,755 feet (839.7 m.) below the Upper Cambrian, in

a ravine running up into Danish Flat from Mill Canyon, about 6 miles (9.6 km.) west-

southwest of Liberty and 15 miles (24.2 km.) west of Montpelier, Bear Lake County,
Idaho.

Le Nisusra ? vaticrna (de Verneuil and Barrande).

Plate XCVII, figures 3, 3a-b.

Orthisina vaticina DE VERNEUIL and BARRANDE [not Satter MS.], 1860, Bull. Soc.

FIGURE 60.—Wisusia rara Walcott. Z 9
Gack Ob Gia a een ae géol. France, 2d ser., vol. 17, pp. 533-535, Pl. VIII, figs. 8, 8a-d. (Described
valve (U.S. Nat. Mus. Cat. No. and discussed in French as a new species; see below for translation. Figs. 8, -
52295a, labeled 52295b[ Walcott, 8b-c are copied in this monograph, Pl. XCVII, figs. 3, 3a-b, respectively.)
1908d, p. 123] by error). Orthisina vaticina de Verneuil and Barrande, Mauzapa, 1875, Bol. Com. Mapa Geoldgico
The specimen represented is Espana, tome 2, p. 32. (Mentioned.)

from Locality 55c, Middle Cambrian

Spence shale, near Liberty, Idaho. The original description by de Verneuil and Barrande follows:

The figure is copied from Walcott 2

[1908d, PI. IX, fig. 13a]. Shell subquadrangular, slightly emarginate below the lateral extremities. Length

equal to three-fourths of the breadth. Hinge ridge somewhat shorter than the greatest
width of theshell. Ventral valve twice as thick as the dorsal, area double in height. Triangular opening on each
of the valves, covered in part by a deltidium. At the point of the beak there is a very fine opening, hardly visible,
which is obliterated in certain specimens. The valves are regularly bulged and have no marked sinus, so that
their edge is straight. The surface is ornamented with fine, dichotomous, spiny striz; these spines, or tubes, which
are 1 or 2 mm. long on the ventral valve, are hardly seen on the other valve. At 10 mm. from the beak, where
the striz subdivide by dichotomy, six of them are counted in a space of 5 mm.

Dimensions: Length, 18 mm.; breadth, 24 mm.; thickness, 8mm.

Relations and differences: This species belongs to the Orthis group, united by one of us under the name of Recto
striate © and which Davidson includes in the genus Orthisina of d’Orbigny.¢ The two characteristics of this group
consist in the direction of the striz, which, starting from the beak, never curve backward to reach the hinge crest,
and in the presence of a deltidium which covers the triangular cleft of the area. The hole with which this deltidium
is sometimes pierced, a characteristic on which d’Orbigny established the genus Orthisina, is of altogether secondary
importance, for it appears to be only temporary. We have demonstrated that in certain Lepteenz, which have an
opening analogous to that of the species under discussion, that characteristic produces no significant change in the
internal apparatus.@

In having its striz provided with tubes or spines this species is distinguished from all others, except O. striatula,
with which it is impossible, on other accounts, to confound it. It may be compared either to O. romingeri Barrande,
from the primordial zone of Bohemia, which is distinguished by a rather pronounced sinus on the small valve, a more
prominent beak and smooth striz; or with O. inflexa Pander, from the lower Silurian strata of St. Petersburg, which
is thicker, as observed especially in the dorsal valve, which in this respect is almost equal to the opposite valve.
Moreover the strize of the Russian species are never spinous.

Mr. Salter, whose kindness is never appealed to in vain, thought he recognized in our specimens a species found
recently in the Lingula beds, to which, in the collection of the museum of practical geology at London, he gave the
name Q. vaticina, under which we publish it.

Observations.—In appearance this shell is closely related to Lower Ordovician species of
Clitambonites that have a fimbriated surface. If, as the authors state, many of the shells are
imperforate, then it is probable that the species is closely related to and belongs with Nisusia,
although the illustration of the spines indicates that they were of a different character from
those of Nisusia festinata (Billings). In the presence of the statement that the shells are
associated with the Primordial fossils (Paradozides, etc.) and the absence of an opportunity to

a See the note accompanying the first reference in the synonymy of Eoorthis thyone, p. 789, and the note following text figures 70A-C, p. 789.

b Murchison, de Verneuil, et de Keyserling, Géologie de la Russie d’Europe et de 1l’Oural, vol. 2, 1845, p.179. Bull. Soc. géo]. France, 2d ser.,
vol. 2, 1845, p. 481.

¢ Davidson, Introduction 4 Vhistoire naturelle des brachiopodes, French translation by Des!ongchamps, p. 130.

d De Verneuil, Bull. Soc. géol. France, 2d ser., vol. 5, 1848, p. 348.

BILLINGSELLID. Tal

study the actual specimens, I think it best to refer the species to Nisusia. “‘Orthis vaticina”’
was a manuscript name given by Salter to shells subsequently referred to ‘“Orthis lenticularis” by
Davidson [1869, p. 231].

FoRMATION AND LOCALITY.—Middle Cambrian: (350 [de Verneuil and Barrande, 1860, p. 538]) Red limestone of
the Paradowides zone, near Adrados, north of Sabero and Bonar, Cantabrian Mountains, Province of Leon, northwestern
Spain. :

JAMESELLA Walcott,” subgenus of NISUSIA.

Nisusia ( Jamesella) Waxcort, 1905, Proc. U.S. Nat. Mus., vol. 28, p. 252. (Characterized as below as a new subgenus.)
Nisusia (Jamesella) Waxcotr, 1908, Smithsonian Misc. Coll., vol. 53, No. 4, Pl. XI, and pp. 142 and 147. (Classifica-

tion of genus.)

There are several species of Lower Cambrian brachiopods that differ from Nisusia festinata
im the absence of the strong spines on the radiating ribs. This character is so marked that I
separate the species without it as a subgeneric group.

Type.—Orthis perpasta Pompeck}.

The subgeneric name is in memory of Dr. Joseph F. James, a paleontologist. who assisted
me in the preparation of material for the study of the Olenellus fauna.

Nisusta (JAMESELLA) Amir Walcott.
si Plate CI, figures 6, 6a-b.

Nisusia (Jamesella) ami Waucort, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 252. (Described and discussed as below as

a new species.)

Ventral valve convex, elevated at the umbo, with the beak slightly incurved; area high,
vertical, shghtly meurved; delthyrium triangular, higher than its greatest width and covered
by a convex deltidium, which is imperforate. Surface of shell marked by numerous fine,
rounded, equidistinet ribs that merease by interpolation; about 8 ribs in a distance of 2 mm.
at frontal margin. Size: Length, 8 mm.; width, 10 mm.; elevation at umbo, 4mm.

The front margin of the deltidium is broken so that it is impossible to state whether it
was arched as is the deltidium of Nisusia festinata (Billings). There is no trace of a foraminal
aperture in the deltidium. The fine, regular ribs and high area serve to distinguish this from
other species of the genus. Dorsal valve unknown.

The specific name was given in honor of Dr. H. M. Ami.

ForMATION AND LOCALITY.—Lower Cambrian: (56a) A limestone bowlder in the Sillery conglomerate, on the
south shore of St. Lawrence River 4 miles (6.4 km.) below Quebec, Canada.

Nisusia (JAMESELLA) ARGENTA Walcott.
Plate CI, figures 9, 9a—b.

WNisusia ( Jamesella) argenta Waucort, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 252. (Described and discussed somewhat
as below as a new species.)

The outline of the ventral valve is subrectangular, with the hinge line a little shorter than
the greatest-width. Strongly convex with a keel-like median elevation extending from the
incurved beak over the elevated umbo to the front margin, with gradually increasing width.
Area low, with the minute beak curving down to and possibly slightly over it.

Dorsal valve depressed, convex, with a rather strong median fold (Pl. CI, fig. 9b); area
unknown.

a The synonymy for this subgenus does not give a complete record of the various genera under which the species now included in Jamesella
were formerly placed; it gives only those references in which the genus is discussed or described. To complete the record the following mere generic
references are listed:

Orthis Feistmantel. Orthis Novak.

Orthis Jahn. Orthis Wentzel.

Orthis Katzer. Orthisina de Verneuil and Barrande [1860, p. 535].
Orthis Krejci. Orthis Pompeckj [1896b, p. 514, 515, and 516].

Orthis Kusta. Protorthis Walcott [1905a, pp. 283 and 285].

(a2 CAMBRIAN BRACHIOPODA.

Surface marked by fine, concentric striz of growth and about five sharp, elevated, radiating
ribs on each side of the two ribs on the median ridge of the ventral valve; the ribs of the dorsal
valve are more regular in spacing and size.

Observations.—This shell has such strong characters that I unhesitatingly give it a specific
name. The only form known to me that resembles it is NV. (J.) kuthani (Pompeck)) (Pl. CI,
figs. 4, 4a—b) from Bohemia.

FORMATION AND LOCALITY.—Lower Cambrian: (1m and 1p) @ Limestones of No. 2 of the Silver Peak group, Barrel

Spring section [Walcott, 1908f, p. 189], about 2.5 miles (4 km.) south of Barrel Spring and 0.5 mile (0.8 km.) east of the
road, in the extreme southeast corner of the Silver Peak quadrangle (U.S. Geol. Survey), Esmeralda County, Nevada.

Nisusia (JAMESELLA) ERECTA Walcott.
Plate CI, figures 5, 5a-b.

Nisusia (Jamesella) erecta Watcott, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 253. (Described essentially as below as a
new species. )

General form transversely semioval; hinge line a little shorter than the greatest width;
Valves subequally convex. Surface marked by strong, broad, sharply rounded ribs, three at the
frontal margin in a distance of 2 mm.; the ribs appear to be simple and unbifurcated from the
umbo to the margin, but owing to the small size of the shell this statement may be modified by
discovery of other specimens. Width, 9 mm.; length, 7 mm. from beak to front of ventral
valve. :
Ventral valve convex; elevated at the umbo, beak marginal. Area high, very slightly
inclined backward; delthyrium large, triangular, length and width equal; deltidium convex,
imperforate, and nearly covering the delthyrium. Dorsal valve regularly convex, most elevated
at the umbo and curving over to the rather low area.

This species is distinguished by its strong, regular ribs and regular convexity of the dorsal
valve.

ForRMATION AND LOCALITY.—Middle Cambrian: (318g) Limestone at the south end of ui Timpahute Range,
Groome district, near the line between Nye and Lincoln counties, Nevada.

WSs NisusiA ? (JAMESELLA ?) KANABENSIS Walcott.

Nisusia? (Jamesella?) kanabensis Waucott, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, pp. 97-98. (Described and
discussed as below as a new species.)

This species is represented by a single broken interior cast of a small ventral valve that.
has a length of 3.5 mm.; width, about 5mm. The cast is convex, with the base of a prominent.
extension that filled the interior of the beak. The surface is finely papillose, which proves that
the interior surface was finely punctate. The casts of the ribs show them to have been rather
sharply rounded and to have increased by bifurcation and interpolation; the absence of all
traces of casts of spine bases on the ribs leads me to refer the species to the subgenus Jamesella.
Area shown only by a narrow rim on one side. The delthyrium was probably quite broad.

The reference of this shell to Nisusia is based on the evidence of the presence of a prolonged.
beak and the character of the ribs. The genus is doubtful, but I do not know of any other to
- which a tentative reference could be made.

The specific name is derived from Kanab Canyon, the type locality.

FORMATION AND LOCALITY.—Upper Cambrian: (75) Thin-bedded limestones just below the base of the Ordovician,
in the Tonto group, near the water’s edge at the mouth of Kanab Canyon, Grand Canyon of the Colorado, Arizona.

Nisusta (JAMESELLA) KUTHANI (Pompeck)j).

Plate Cl, figures 4, 4a-b.

Orthis kuthani Pompxrcxs, 1896, Jahrb. K.-k. geol. Reichsanstalt, Bd. 45, pp. 514-515, PI. XV, figs. 8-13. (Described
and discussed in German as a new species; see p. 733 for translation.)
Orthis romingeri of the following authors: Krescr, Novak, K. FrrsrmantTeL, Kusta, Katzpr, WENTZEL, and JAHN.

a 1p is the type locality.

BILLINGSELLID. 139

Nisusia ( Jamesella) kuthani Pompeckj, Waucorr, 1905, Proc. U. 8. Nat. Mus., vol. 28, pp. 253-254. (Original descrip-
tion, Pompeckj, 1896b, p. 514, copied, and species discussed as below.)

The original description by Pompeckj follows:

Outline subrectangular, hinge edge straight with angles protracted but a short distance; length to breadth as
3:4, often less.

Ventral valve highly arched. Apex drawn forward, but not curved toward the dorsal valve at all, or in rare cases
but slightly. Area high, steep, with sharp areal edges and high, triangular foramen. Owing to the state of preserva-
tion, the details of the interior of the valves can not be well observed.

Dorsal valve flatter, with rather decided arching on side edge and frontal edge, with sinus always distinct, which
corresponds to a faint swelling at the frontal edge of the ventral valve. The area is very low with a small triangular
foramen. Crural processes narrow, considerably divergent.

The surface is ornamented with narrow sharp ribs, increasing by interpolation. The ribs are divided by inter-
spaces which are considerably broader than the ribs. In the interspaces there is frequently seen a lower, threadlike
rib. The number of ribs is 30 to 36. The ribs are mostly very distinct on the internal casts also. Sometimes internal
casts are found which show remarkably few ribs, and which in this respect and also in their greater breadth approach
Orthis perpasta var. macra. é

The present species has thus far been called, after Kusta’s example, Orthis romingeri, but it differs from that
species (a) in the ventral valve, its apex never being so strongly curved as in Orthis romingeri, and in most cases not
eurved at all; (b) in the dorsal valve, which in the present species is more strongly arched with a more decided sinus;
(c) in the sculpture, inasmuch as the ribs are narrower, sharper, fewer in number, and separated by wider interspaces
than in Orthis romingeri Barrande.

Observations.—In the material of this species sent me by Doctor Pompeck] there is one
east of a ventral valve that shows that a convex deltidium covered about two-thirds of the
delthyrium; its front margin was arched so as to leave considerable space open between it
and the plane of the hinge line.

There is a decided mesial sinus in most specimens of the dorsal valve, but in some it is
flattened so as scarcely to break the uniform low convexity of the valve; the strength of the
mesial elevation of the ventral valve also varies from a marked ridge to a flattened median
space.

The species appears to be quite distinct from any described Cambrian form.

The specific name was given in honor of Mr. Wilhelm Kuthan, of Tejtovik, Bohemia,
Austria-Hungary.

ForMATION AND LOCALITY.—Lower Cambrian: Conglomeratic sandstones and graywacke inclusions in the lower
conglomerate zone of the Kamenné hurka at the following localities [Pompeckj, 1896b, p. 514]: (845i)¢ near Tejrovik,
and (345j) at Gross Lohoyic, southwe:t of Skrej; both in Bohemia, Austria-Hungary.

(345k)¢ Sandstones at Slapnicky mlyn, near Skrej, Bohemia, Austria-Hungary.

Nisusta (JAMESELLA) Lowr Walcott.

Text figures 61A—D, page 734.

Nisusia (Jamesella) lowt Watcott, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, p. 98, Pl. IX, fig. 14. (Characterized
and discussed essentially as below as a new species. Fig. 14 is copied in this monograph as fig. 614.)

The description of the form, outline, convexity, and cardinal area of the ventral valve
of Nisusia festinata (Billmgs) (Pl. C, figs. 1, la-e) is so applicable to this species that I will
refer the student to it for the description of those features. The surface of NMisusia (James-
ella) low differs from that of N. festinata in having more and finer radiating ribs, clearly defined,
rounded, concentric striz and lines of growth, andin the absence of all traces of the surface spines
so characteristic of N. festinata. The latter is also a larger species. Nisusia (Jamesella)
lowi averages 10 to 12 mm. across the hinge line and rarely over 8 mm. in the length ot the
ventral valve of the large shells of the species.

There is a close relationship between Msusia alberta (Walcott) (Pl. C. figs. 3, 3a-d) and
NV. (J.) lowi in form and size. JN. alberta has a spinose surface, and the beds in which the two
species occur are separated by 1,700 feet of limestone.

@ Localities 345i and 345k are represented in the collections of the United States National Museum.

oan CAMBRIAN BRACHIOPODA.

The specific name is given in honor of Hon. A. P. Low, deputy head and director of the
Geological Survey of Canada.
- Misusia (Jamesella) lowi occurs at horizons 186 to 294 feet (56.7 to 89.6 m.) above the
horizon of Nisusia festinata (Billings) i the Mount Stephen section.
FORMATION AND LOCALITY.—Lower Cambrian: (58k) Just below the Middle Cambrian in limestones forming 1 of

the Mount Whyte formation [ Walcott, 1908c, p. 240 (9)], just above the tunnel; (58p) drift block of limestone believed
to have come from the limestone forming 1 of the Mount Whyte formation [Walcott, 1908c, p. 240 (9)], found near the

D
FIGURE 61.—Wisusia (Jamesella) lowi Walcott.—A, A’, A’, Top, side, and enlarged view (X9) of exterior surface of a partly exfoliated ventral
valve, the type specimen, in limestone (U.S. Nat. Mus. Cat. No. 53677a). B, B’, B’, Top, side, and back views of cast of the interior of a
ventral valve, in limestone (U. S. Nat. Mus. Cat. No. 53677b). C, View of the cast of the interior of a small dorsal valve, in limestone
(U.S. Nat. Mus. Cat. No. 53677¢). D, A compressed dorsal valve in siliceous shale (U. S. Nat. Mus. Cat. No. 57072a).
The specimens represented by figures 61A, 61B,and 61C are from Locality 58k, and that represented by 61D is from Locality 57m, both in
the Lower Cambrian on Mount Stephen, British Columbia. Figure 61A is copied from Walcott [1908d, Pl. VIII, fig. 14].

Canadian Pacific Railway just west of the tunnel; and (57m) about 50 feet (15.2 m.) below the Middle Cambrian in a
siliceous shale correlated with 1b of the Mount Whyte formation on Mount Bosworth [Walcott, 1908f, p. 213], just above
the tunnel; all on the north shoulder of Mount Stephen, 3 miles (4.8 km.) east of Field, British Columbia, Canada.
(57s) About 160 feet (49 m.) below the Middle Cambrian near the base of the gray oolitic limestone forming 1b
of the Mount Whyte formation [Walcott, 1908f, p. 212], on Mount Bosworth, north of the Canadian Pacific Railway
between Hector and Stephen, on the Continental Divide between British Columbia and Alberta, Canada.

L NisusiA (JAMESELLA) NAUTES (Walcott).

Plate XCIII, figures 6, 6a-b.

Protorthis nautes Waucorr, 1905, Proc. U. S. Nat. Mus., vol. 28, pp. 283-284. (Characterized and discussed some-
what as below as a new species.)

This species has the same type of punctate interior surface as N. (J.) spencei, and casts of
the exterior are marked by minute, closely set papille that are casts of the puncte in the shell.
Traces of the shell show the same type of papille and it is highly probable that the shell was
punctate. The exterior form is like that of Nisusia alberta, but in the surface ribs it differs
from the latter and other described species of the genus.

A ventral valve has a length of 5 mm.; width, 8 mm. A dorsal valve, length, 7 mm.;
width, 10 mm. There is considerable variation in the relative proportions between length and
width.

FORMATION AND LOCALITY—Middle Cambrian : (55c and 163) 4 Spence shale member of the Ute limestone [ Walcott,
1908a, p. 8], about 50 feet (15.2 m.) above the Brigham quartzite, and 2,755 feet (839.7 m.) below the Upper Cambrian,
in a ravine running up into Danish Flat from Mill Canyon, about 6 miles (9.6 km.) west-southwest of Liberty and 15
miles (24.2 km.) west of Montpelier, Bear Lake County, Idaho. ;

a 168 is the type locality.

BILLINGSELLID. (35

Specimens that are somewhat doubtfully referred to Nisusia (Jamesella) nautes occur at
the following localities:

(15c) Limestone in the Marjum limestone, near Swasey Spring; and (11q) about 2,350 feet (716.3 m.) above
the Lower Cambrian, and 2,050 feet (624.8 m.) below the Upper Cambrian in the limestone forming 1c of the Marjum
limestone [Walcott, 1908f, p. 180] ridge east of Wheeler Amphitheater; both in the House Range [Walcott, 1908f, Pls.
XIII and XV], Millard County, Utah.

(57£) About 2,200 feet (670.6 m.) above the Lower Cambrian, and 2,800 feet (853.4 m.) below the Upper Cambrian,
in the limestone forming 1 of the Stephen formation [Walcott, 1908f, p. 209], about 0.5 mile (0.8 km.) east of the
‘*fossil bed,’’ on the northwest slope of Mount Stephen, above Field, on the Canadian Pacific Railway, British Columbia,
Canada.

/ NisusiA (JAMESELLA) PELLICO (de Verneuil and Barrande).

Plate XCVII, figures 2, 2a-b.

Orthisina pellico DE VERNEUIL and BARRANDE, 1860, Bull. Soc. géol. France, 2d ser., vol. 17, pp. 535-536, Pl. VIII,
figs. 7, 7a-b. (Described and discussed in French as a new species; see below for translation. Figs. 7, 7a—b
are copied in this monograph, Pl. XCVII, figs. 2, 2a—b, respectively.) :

The original description by de Verneuil and Barrande follows:

Shell rather small, transverse, breadth greater than length by one-fourth, cut off squarely at the extremities.
Hinge crest attains the greatest breadth of the shell. Ventral valve twice as deep as dorsal valve, provided with an
area of twice the height, which rises perpendicularly and forms a right angle with the hinge crest. The opening is
only partly covered with a deltidium, which descends from the tip of the beak. On the other valve the bare rudi-
ments of a similar deltidium may be perceived.

Neither valve has a sinus, and their commissure presents no wavy contours.

The surface is ornamented with rather wide-spaced striz. Three or four principal strize are counted on the sides,
and two or three intermediate finer ones. The median region is bounded by two pronounced striz, between which
two or three fainter ones are distinguished.

Dimensions: Breadth, 11 mm.; length, 8 mm.; thickness, 5 mm.

Relations and differences: In having its area partly covered with a deltidium this species comes within the genus
Orthisina, as understood by Mr. Davidson, but it no longer shows the needle-shaped hole of the tip, on which d’Orbigny
had established the genus. However, the analogy which it maintains with the preceding species does not admit of
its being placed in any other genus, and shows how slight is the importance of the characteristic used by the author
just named. The position of the area, with regard to the hinge, recalls O. adscendens, which is clearly distinguished
from our species by the nature of its strie.

From this last-named point of view O. pellico approaches the Lepteenze more than it does most of the other Orthis
or Orthisina species.

Observations.—As far as the illustrations and description can determine, this species belongs
with the nonspinose forms of Nisusia grouped under the subgenus Jamesella.

The authors of the species state [1860, p. 536] that this shell was found in the red limestone
with their ‘“Orthis primordialis.”

FoRMATION AND LOCALITY.—Middle Cambrian: (350 [de Verneuil and Barrande, 1860, p. 538]) Red limestone of
the Paradoxides zone, near Adrados, north of Sabero and Boar, Cantabrian Mountains, Province of Leon, northwestern
Spain.

Nisusta (JAMESELLA) PERPASTA (Pompeckj).

Plate CI, figures 1, la—h.

Orthis perpasta PompEcxs, 1896, Jahrb. K.-k. geol. Reichsanstalt, Bd. 45, pp. 515-516, Pl. XV, figs. 15-18. (Described
and discussed in German as a new species; see below for translation. Fig. 16d is copied in this monograph,
Pl. Cl, fig. 1g.)

Nisusia ( Jamesella) perpasta Pompeckj, Watcorr, 1905, Proc. U.S. Nat. Mus., vol. 28, pp. 254-255. (Original descrip-
tion, Pompeckj, 1896, pp. 515-516, copied, and species discussed as essentially on p. 736.)

The original description by Pompeckj follows:

Outline subrectangular, with straight hinge line and slightly bent frontal margin; cardinal angles slightly drawn
in; the length is little more than half the breadth, the greatest breadth being in the middle of the valves. Both valves
are very strongly arched.

The ventral valve has a high, steep area, with a large triangular foramen, and the areal edges are rather sharp.
The apex is not drawn forward beyond the hinge line.. From the apex to the frontal edge there is a sinus which
gradually increases to a considerable breadth. The dorsal valve, which is also strongly arched, has a very low and

736 CAMBRIAN BRACHIOPODA.

indistinct area, with a low, broadly triangular foramen. On the frontal margin a strong, broad swelling of the edge
of the valve corresponds to the sinus of the ventral valve.

Judging by some internal casts and impressions, the shell is omamented with some 40 broad ribs, of which about
half are inserted between the primary ribs at various distances from the apex. Concentric lines of growth cross the
ribs. On the top of the shells, along some of these lines of growth (1 or 2) the sections of the shell are found to be
imbricated; near the frontal edge such imbrication is present more frequently in very short intervals.

Orthis perpasta differs from Orthis kuthani in its greater breadth, in the almost uniform and much stronger arching
of both valves, and also in the fact that in the former species the ventral valve bears a sinus, whereas in Orthis kuthani
the sinus is on the dorsal valve.

Observations —Doctor Pompeckj very kindly sent me several fragments of sandstone con-
taining casts of the interior and exterior of the valves. The specimens illustrated by Pompeckj
[1896b, Pl. XV] are smoother than most of those sent to me, but the description corresponds to
the ribbed specimens and a few nearly smooth interior casts occur im association with the more
strongly ribbed shells. The convexity of the ventral valve is quite variable, but is usually
considerable. One of the marked characters of the dorsal valve is the large transverse space
(pseudocruralium) inside the valve beneath the umbo. In one example it is crossed vertically
by the main vascular sinuses. What may be a trace of a low, simple, rounded cardinal process is
shown in one cast. The crura were strong, with small dental sockets beside them.

Nisusia (Jamesella) perpasta resembles Misusia alberta (Walcott) in form and convexity,
but it does not have a spinose surface.

ForMATION AND LOCALITY.2—Lower Cambrian: Conglomeratic sandstones and graywacke inclusions in the lower
conglomerate zone of the Kamenn4 htrka at the following localities [Pompeckj, 1896b, p. 516]: (845i) near Tejrovik;

and (345j) at Gross Lohovic, southwest of Skrej; both in Bohemia, Austria-Hungary.
(345k) Sandstones at Slapnicky mlyn, near Skrej, Bohemia, Austria-Hungary.

Nisusia (JAMESELLA) PERPASTA MACRA (Pompeckj).
Plate Cl, figures 3, 3a.

Orthis perpasta macra PompEcKs, 1896, Jahrb. K.-k. geol. Reichsanstalt, Bd. 45, p. 516, Pl. XV, fig. 14. (Charac-
terized in German as a new variety; see below for translation. Iig. 14 is copied in this monograph, Pl. CI,
fig. 3a.)

Nisusia (Jamesella) perpasta macra Pompeckj, Waucort, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 255. (Original char-
acterization copied and variety discussed as below.)

The original description by Pompeckj follows:
Some internal casts and impressions of dorsal valves agree in outline perfectly with the dorsal valves of Orthis
perpastc, but differ from the type form by much less arching and ribs farther apart.

Observations.—The gradual increase in the width of the interspaces between the ribs, from
a very narrow space to several times the width of the rib, makes this variety of doubtful value.

FoRMATION AND LOCALITY.—Lower Cambrian: Conglomeratic; quartzitic sandstones and graywacke inclusions
in the zone of the Kamenné hurka at the following localities [Pompeckj, 1896b, p. 516]: (345i) near Tejrovik; and (345j)
at Gross Lohovic, southwest of Skrej; both in Bohemia, Austria-Hungary.

Nisusia (JAMESELLA) PERPASTA SUBQUADRATA (Pompeck]).
Plate Cl, figures 2, 2a—b.

Orthis perpasta subquadrata Pomprcks, 1896, Jahrb. K.-k. geol. Reichsanstalt, Bd. 45, p. 516, Pl. XV, figs. 19 and°20.
(Described and discussed in German as a new variety; see below for translation. Figs. 19a and 20a are copied
in this monograph, Pl. Cl, figs. 2a and 2b, respectively.)

Nisusia (Jamesella) perpasta subquadrata Pompeckj, Watcort, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 255. (Original
description copied, and variety discussed as on p. 737.)

The original description by Pompeckj follows:

As compared with the type form, this variety is distinguished by less breadth, the length being to the breadth
as 3to4. The anterior angles of the straight hinge edge are drawn in somewhat more than those of Orthis perpasta.
The ventral valve is higher, with higher and steep area, pierced by a large triangular foramen. The sinus, which

a Localities 345i and 345k are represented in the collections of the United States National Museum.

BILLINGSELLIDZ. eae

extends from the high vertical apex to the frontal edge, is bordered by obtusely rounded edges. Dorsal valve pro-
portionally more bulged than in the type form. Sculpture as in Orthis perpasta.

The outer form strikinely recalls Orthisina; but the pseudodeltidium, the median septum, and the spondylium
of the ventral valve are lacking.

Orthis perpasta var. subquadrata was found in several internal casts and impressions, together with Orthis perpasta,
more rarely in graywacke sandstone than in the conglomerate-like, quartzitic sandstone.

Observations.—This variety apparently is not constant, as ventral valves occur in the
material before me that have the subquadrate form with relatively less convexity than the
convex forms of the species perpasta.

FORMATION AND LOCALITY.—Lower Cambrian: Conglomeratic sandstones and graywacke inclusions in the lower
conglomerate zone of the Kamenn4 htrka at the following localities [Pompeckj, 1896b, p. 516]: (345i) near Tejrovik;
and (345j) at Gross Lohovic, southwest of Skrej; both in Bohemia, Austria-Hungary.

Nisusta (JAMESELLA) SPENCEI (Walcott).

Text figure 62; Plate XCIII, figures 7, 7a.
Protorthis spencei Watcott, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 285. (Described as below as a new species.)

This is a strongly marked species, despite the fact that the few specimens that have been
found are flattened in the shale.- It is distinguished by its rounded, subquadrate outlines
and narrow, sharp ribs with strong interspaces, six ribs in a dis-
tance of 5 mm. at the front margin. The area of the ventral valve
has a broad delthyrium with a convex deltidium covering the
ereater part of it. The interior surface of the shell is finely punc-
tate. A flattened ventral valve has a length of 17 mm.; width,
18 mm.

This shell is associated with Misusia (Jamesella) nautes (Wal-
cott). It differs from it in its larger size, sharper ribs, and broader
interspaces between the ribs.

The discovery in the collection of 1907 of a specimen of a
ventral valve showing a very perfect area and arched deltidium
proves that the specimen upon which the reference to Protorthis sa ae pre cls eenae
was based had the deltidium crushed so that it was concave, thus valve and ylew of cardinal area.
causing it to be mistaken for the free spondylium of Protorthis. Wine) Suweiere AG nsoaed WS Hea

‘ 5 O 5 Locality 55¢e, Middle Cambrian Spence

The specific name is given in honor of Mr. R.S. Spence, of \ shale, near Liberty, Bear Lake County,

Evanston, Wyoming. Idaho(U.S. Nat. Mus. Cat. No. 52435a).

ForMATION AND LOCALITY.—Middle Cambrian: (55c and 163) Spence shale member of the Ute limestone | Walcott,
1908a, p. 8), about 50 feet (15.2 m.) above the Brigham quartzite and 2,755 feet (839.7 m.) below the Upper Cambrian, in a
ravine running up into Danish Flat from Mill Canyon, about 6 miles (9.6 km. ) west-southwest of Liberty and 15 miles
(24.2 km.) west of Montpelier, Bear Lake County, Idaho.

(11q) About 2,350 feet (716.3 m.) above the Lower Cambrian and 2,050 feet (624.8 m.) below the Upper Cam-

brian in the limestone forming 1c of the Marjum limestone [Walcott, 1908f, p. 180], ridge east of Wheeler Amphitheater
[Walcott, 1908f, Pls. XIII and XV], House Range, Millard County, Utah.

Nisusia (JAMESELLA) UTAHENSIS Walcott.

Plate CI, figures 10, 10a.

Nisusia ( Jamesella) utahensis Watcotr, 1905, Proc. U. 8S. Nat. Mus., vol. 28, pp. 255-256. (Described and discussed
as below as a new species. )

Ventral valve transverse, strongly convex; most elevated at the umbo, which is sur-
mounted by the upward pointing apex at the edge of the area; area slightly inclined forward
from the hinge line; delthyrium large and covered by a convex deltidium. Surface marked
by several strong, rounded ribs irregularly alternating with smaller ribs; fine radiating striz
occur on the ribs and interspaces.

@ 163 is the type locality.
62667°—vot 51, pr 1—12——47 :

’

738 CAMBRIAN BRACHIOPODA.

Only two specimens of somewhat imperfect ventral valves are known of this species.
The description is of the best-preserved specimen. The second specimen has a greater num-
ber of more regular ribs that increase by interpolation of short ribs. The specimen illustrated
has a width of 8 mm. and a length of 4.5 mm. from the apex to the front margin, which is
about the distance from the hinge line to the front margin.

The nearest related species is Nisusia alberta (Walcott), from which it differs in surface
ribs, forward inclination of the area, and prominent convex deltidium.

FoRMATION AND LOCALITY.—Middle Cambrian: (7w) Limestone in Rock Canyon, in the Wasatch Mountains east
of Provo, Utah County, Utah.

Nisusta (JAMESELLA) sp. undt. Walcott

Nisusia (Jamesella) sp. undt., Waxcorr, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 256. (Characterized as below as an
undetermined species.)

This doubtful species is based on an interior cast of a broken ventral valve. The width
of the shell is 15 mm., and length 8 mm., with apex broken off. A broad, shallow sinus arches
the frontal margin, and narrows toward the umbo. Radiating ribs narrow, about five in a
space of 2 mm.

FoRMATION AND LOCALITY.—Lower Cambrian: (392a) Limestone at L’Anse au Loup, on the north shore of the
Straits of Belleisle, Labrador.

Genus PROTORTHIS Hall and Clarke.@
[zod, early; and Orthis.]

Protorthis Hatt and CLARKE, 1892, Eleventh Ann. Rept. State Geologist New York for 1891, pp. 273-274. (Described
as in first two paragraphs below.)

Protorthis Haut and CLarKe, 1892, Forty-fiitth Ann. Rept. New York State Museum for 1891, pp. 589-590. (Copy
of preceding reference. )

Kutorgina Hatt and Cxarke [not Watcorrt], 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, pp. 90-94. (Copies
Walcott’s description, 1886b, pp. 101-102, and discusses genus, but description and discussion also include
reference to specimens now referred to Protorthis, Billingsella, Micromitra, Micromitra (Paterina), and Micromitra
(Iphidelia).)

Protorthis Hatt and CiarKe, 1892, idem, pp. 231-233. (Described and discussed asa new genus. With two omissions
this reference is copied below.)

Billingsella Hall and Clarke, ScHucuErt (in part), 1897, Bull. U. 8. Geol. Survey No. 87, p. 158. (Characterized
and discussed. The genus Protorthis is placed as a synonym of Billingsella, and among the species referred
to the latter genus are species belonging with both Protorthis and Nisusia.)

Protorthis Hall and Clarke, Waucorr, 1905, Proc. U. S. Nat. Mus., vol. 28, pp. 280-281. (Copies Hall and Clarke,
1892c, pp. 231-233, and discusses genus as on p. 739.)

Protorthis Hall and Clarke, GRaBAvU and Samer, 1907, North American Index Fossils, vol. 1, p. 211. (Characterized. )

Protorthis Hall and Clarke, WAtcoTt, 1908, Smithsonian Misc. Coll., vol. 53, No. 4, Pl. XI, and pp. 142and 147. (Classi-
fication of genus.)

Hall and Clarke [1892c, pp. 231-233] described the species as follows:

Shells small, transversely subquadrate or semicircular. Hinge line straight, its length being equal to the greatest
width of the valves. Valves unequally biconvex, or subplanoconvex, the pedicle valve being the larger. The car-
dinal area is narrow on both valves, but is higher on the (ventral) pedicle valve, and is transected by a broad delthy-
rium which is closed below by a concave plate apparently produced by the union of the dental lamellae, which are
not continued to the bottom of the valve; teeth distinctly developed. In the brachial (dorsal) valve the cardina!
area also bears an open delthyrium; the dental sockets are obscure and the crural plates small; the latter appear to
unite and form a low elevation across the base of the delthyrium. Cardinal process absent or rudimentary in all
the specimens examined. Muscular markings in both valves extremely obscure.

a The synonymy for this genus does not give a complete record of the various genera under which the species now included in Protorthis were
formerly placed; it gives only those references in which the genus is discussed or described. To complete the record for the species taken up in
the monograph the following mere generic references are listed:

Orthis Tlartt [1868, p.644; 1878, p. 644]. Orthisina? Matthew [1891, p. 131].

Orthis \Valeott [1884a, p. 17]. Orthis (Protorthis) Wysog6rski [1900, p. 227].
Kutorgina Matthew [1886, p. 42]. Protorthis (Billingsella) Grabau and Shimer [1907, p.
Orthis Matthew [1886, p. 43]. 211].

Orthis Hartt (1891, p. 644].

BILLINGSELLIDA. 13)

Surface marked by distinct plications, with interstitial finer radii, which are crossed by delicate concentric
striz; these are usually accompanied by a low sinus and fold on the brachial and pedicle valves, respectively; interior
very finely papillose. Shell substance fibrous and apparently punctate.¢

The characters of the St. John species are eminently comprehensive; first, the form of the shell is one more fre-
quently met with among the strophomenids than among the orthids; the concave plate formed by the union of the
dental lamellze is never found in Orthis proper, though occurring in Scenidiwm. In Orthisina or Clitambonites this
plate is always present, but always supported by a median septum and invariably accompanied by the convex del-
tidium, which, so far as known, does not exist in Protorthis; while in the group typified by Orthis pepina Hall (here
designated by the term Billingsella), the convex deltidium of Clitambonites is present and the concave or dental plate
absent. The apparent absence of a cardinal process in Protorthis may be due to the imperfections of the fragile shells
studied. The specimens of the St. John shells are preserved as external and internal casts, and from some of these
there is reason to infer that the substance of the shell was punctate.

Type —Orthis billings: Hartt.

Observations.—A study of the various species here described under the genus Protorthis
has not given data that will add to the above generic description. All of the species have
evidence of puncte of greater or less depth on the inner and outer surfaces of the shell, but in
none of them have punctz been found that penetrated through the shell; this may be owing
largely to the fact that all of the species are preserved as casts in the sandstone or shale and
none of them have the original shell substance or a calcareous or siliceous replacement of it.

A careful examination of a large number of specimens of the dorsal valve fails to reveal.
a true cardinal process.

PROTORTHIS BILLINGSI (Hartt).

“ Plate XCIX, figures 1, la-e.

Orthis billings: Harrr, 1868, Acadian Geology, by Dawson, 2d ed., pp. 644-645, fig. 223. (Described. The specimen
represented by fig. 223 is not figured in this monograph, but it is redrawn by Walcott, 1884a, Pl. I, fig. 1c.)

Orthis billingst Hart, 1878, idem, 3d ed., pp. 644-645, fig. 223. (Copy of preceding reference.)

Orthis billings: Hartt, Waxcorr, 1884, Bull. U.S. Geol. Survey No. 10, pp. 17-18, Pl. 1, figs.1, la-d. (Original descrip-
tion, Hartt, 1868, pp. 644-645, copied and species discussed. None of the specimens represented by figs. 1, la—d
are figured in this monograph. Fig. lc is drawn from the specimen figured by Hartt, 1868, p. 644, fi. 223.)

Orthis billingsi, Hartt, Marraew, 1886, Trans. Roy. Soc. Canada, Ist ser., vol. 3, sec. 4, No. 4, p. 43. (Discussed.)

Orthis billingsi Hart, 1891, Acadian Geology, by Dawson, 4th ed., pp. 644-645, fig. 223. (Copy of Hartt, 1868, pp.
644-645.)

Orihasina? billings Hartt, MarruEw, 1891, Trans. Roy. Soc. Canada, Ist ser., vol. 8, sec. 4, No. 6, p. 131. (Discussed
and generic reference changed.) °

Protorthis billingsi (Hartt), Havu and CrarKe, 1892, Eleventh Ann. Rept. State Geologist New York for 1891, p. 274,
Pl. VIII, figs. 3-7. (Mentioned.)

Protorthis billingsi (Hartt), Hart and CLarKe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt.1, pp. 219 and 232,
Pl. VITA, figs. 14-20. (Discussed. Figs. 14-20 are copied from Hall and Clarke, 1892a, Pl. VIII, figs. 5, 7, 3,
4, and 6, respectively.)

Billingsella billingsi (Hartt), ScnucuErt, 1897, Bull. U. S. Geol. Survey No. 87, p. 158. (Merely changes generic
reference.) :

Orthis (Protorthis) billingsi (Hartt), Wysocorsxt, 1900, Zeitschr. Deutsch. geol. Gesell., Bd. 52, p. 227, footnote.
(Discussed in German.)

Protorthis billingsi (Hartt), Waxcorr, 1905, Proc. U. 8. Nat. Mus., vol. 28, pp. 281-282. (Described and discussed as
below.)

Protorthis (Billingsella) billingsi (Hartt), GraBau and Sumer, 1907, North American Index Fossils, vol. 1, p. 211,
fig. 250. (Described. The five figures included in fig. 250 are all copied from Walcott, 1884a, Pl. I, figs. 1, lad.)

The generic description follows very closely that of the type species Protorthis billings: in
its main features. All of the specimens are compressed in the embedding shale, which renders
it difficult to get a true conception of the convexity and form of the valves. The general form
is shown by the illustrations. The outline may be transversely quadrilateral or subsemicircular
(Pl. XCIX, figs. 1 and le) or subquadrate (figs. la-f). Usually the beak is inclined backward
over the area, but it may be distorted by pressure so as to appear to incline forward. Young
shells have a well-defined median sinus on the ventral valve that shows as a flattened space on
the larger shells. A slight smus sometimes appears on the dorsal valve. The surface of the
shell varies in the number and size of the radiating ribs; sometimes they are scarcely visible

a The casts of the interior of the valves indicate that the inner layer of the shell is punctate, but I have been unable to obtain any evidence
that the shell had the fibrousor punctate structure characteristic of Dalmanella.

740 ; CAMBRIAN BRACHIOPODA.

toward the cardinal margin, and in other shells they are clearly defined all over the surface;
the increase in number is by bifurcation and interpolation; fine, threadlike concentric striz
and strong squamose lines of growth cross the ribs.

Ventral valve moderately convex, with the umbo and apex slightly curved over the area
(Pl. XCIX, fig. 1), or erect above the area (Pl. XCIX, fig. 1b). The cardinal area appears to be
slightly concave; divided midway by a triangular delthyrrum, which is more or less closed by a
concave plate that Hall and Clarke consider [1892c, p. 231] to be formed by the extension of the
dental plates or lamellz; from the casts it appears that the teeth were well developed and sup-
ported by dental plates that united at the center opposite the delthyrium, but did not reach the
bottom of the valve or a median septum; the free spondylium, varied in length from a narrow
rim opposite the head of the delthyrium to a plate two-thirds or more of the length of the
delthyrium.

Dorsal valve uniformly and moderately convex, with the apex curved over to the edge of
the low area; area divided by a broad delthyrium; casts of the interior show that the crure
were strong, dental sockets shallow, and that the crural plates extended across the umbonal
cavity, uniting to define what may be called a pseudocruralum. No trace of a cardinal process
has been seen in a large number of casts of the mterior, and Hall and Clarke did not find any
in a large amount of material.

The casts of the interior show that the mner layer of the shell was minutely punctate, and
a shell preserving some of the inner layers has every appearance of such a structure.

Observations.—This species differs from all recognized species of the genus by its surface
ribs and strive.

The specific name was given in honor of Mr. E. Billings. 7

FORMATION AND LOCALITY.—Middle Cambrian: (2e) Shale 25 feet (7.6 m.) above the basal quartzite, on Seeley
Street, St. John; (3b) shale at the base of the Paradoxides zone, at the head of Seeley Street, St. John; (301k) St. John
formation in the city of St. John; (801g) sandstones of Division 1c of Matthew, at Portland (now a part of the city o
St. John); (308h and 308i) shales in Portland (now a part of the city of St. John); (801j) shales of the St. John formation
at Ratcliffs Millstream; and (21 and 2m) limestone at the base of the Paradomides zone [Matthew, 1895a, p. 108], on Han-
ford Brook; all in St. John County, New Brunswick, Canada.

PROTORTHIS HELENA Walcott.
Plate XCIX, figures 4, 4a—b.

Protorthis helena Waucort, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 282. (Characterized and discussed essentially as
below as a new species.)

This species is founded on the cast of a ventral valve associated with Trematobolus kempanum
(Matthew). The form of the spondylium and area is much lke that of Protorthis latowrensis
(Matthew) (Pl. XCIX, figs. 3b and 4b), but the smooth shell with its broad, rounded mesial
sinus is unlike that species and also other species of the genus. The shell appears to have
been thicker than that of P. latowrensis. Only traces of growth lines are preserved on the
cast. The ventral valve is 10 mm. long, with a width of 14mm. The cast shows that the teeth
and dental plates were unusually strong.

This species differs from all others of the genus by its smooth or nearly smooth surface and
strong median sinus. It suggests Syntrophia barabuensis (Winchell) at first sight, but there is
no evidence of a median septum supporting the spondylium.

The specific name was given for Mrs. Walcott, who collected the specimen.

FoRMATION AND LOCALITY.—Middle Cambrian: (2u) Lowest beds exposed on the south side of Long Island, Ken-
nebecasis Bay [Matthew, 1898a, pp. 124 and 127], St. John County, New Brunswick, Canada.

PROTORTHIS ? HUNNEBERGENSIS Walcott.
Plate XCY, figures 5, 5a—-c.

Protorthis ? nunnebergensis Waucort, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 284. (Described and discussed as on p.
741asanew species. Thename ‘‘nunnebergensis” was used under the impression that the correct spelling of
the type locality was Nunneberg; the species occurs on Hunneberg.)

BILLINGSELLIDA. 741

Protorthis ? hunnebergensis Walcott, Moprre and SEGERBERG, 1906, Medd. fran Lunds Geol. Faltklubb, Ser. B, No.2
(Aftryck ur K. Fysiografiska Sillskapets Handl., N. F., Bd. 17), pp. 70-71, Pl. II, figs. 5,5a-c. (Described and
discussed. Figs. 5, 5a-c, in common with the remaining figures on Pl. II of Moberg and Segerbere’s paper,
were copied from a preliminary photograph of Pl. XCV of this monograph.)

Shell transversely semielliptical, plano-convex. Surface with very fine ribs that increase
by interpolation and bifurcation; on some shells bands of slender ribs are delimited by stronger
ribs, usually 2 to 5, between 2 more prominent ribs; fine concentric striz give a crenulated
aspect to the radiating ribs. Casts of the interior and exterior appear to be minutely papillose,
indicating punctz in the shell.

Ventral valve moderately convex, with the apex curved down to the margin of the area;
area and interior unknown. Dorsal valve flat or very slightly concave between the umbo
and margins; apex slightly elevated above the plane of the surface and cardinal line; a median
sinus is present in some shells.

Observations. —It is a little hazardous to refer this species to Protorthis, as only the general
form and surface are known. The nearly plano-convex valves and surface relate it more
nearly to Protorthis than to Plectorthis, and it does not appear to fall within Leptena, Rafi-
nesquina, or Strophomena. The specimens were collected by Mx. Schmalensee in a dark, argil-
laceous shale above the Ceratopyge limestone and below the lower graptolite shale.

The specific name is derived from Hunneberg, Sweden.

FoRMATION AND Locatiry.—Passage beds between the Upper Cambrian and the Ordovician: (890f) Shales
between the “lower graptolite slate” and the Ceratopyge limestone, at Mossebo, on Hunneberg, western boundary of
the Province of Skaraborg, Sweden.

Prorortuis Lavis Walcott.

Plate XCIX, figures 6, 6a-b.
Protorthis levis WaLcotTT, 1905, Proc. U. 8. Nat. Mus., vol. 28, p. 288. (Described and discussed as below as a new
species. )

Ventral valve transversely semicircular, moderately convex; surface of cast smooth; area
overhanging the hinge line at about 30° from the plane of the margin of the valve. The cast
shows a very clearly defined free spondyhum. Shell about 6 mm. in width and 4 mm. in
length.

This is one of the few representatives of the genus known outside of the Atlantic basin
Cambrian fauna. Its smooth surface and inclined area distinguish it from other species of the
genus.

FORMATION AND LOCALITY.—Upper Cambrian: (79a) “St. Croix sandstone” in a quarry and ledge 0.5 mile
(0.8 km.) southeast of the county courthouse, Menomonie, Dunn County, Wisconsin.

PROTORTHIS LATOURENSIS (Matthew).
Plate XCIX, figures 3, 3a-d.

Kutorgina latourensis MartHEw, 1886, Trans. Roy. Soc. Canada, vol. 3, sec. 4, No. 4, pp. 42-48, Pl. V, figs. 18, 18a-c.
(Described and discussed. None of the specimens represented by figs. 18, 18a-c are figured in this monograph.)

Kutorgina latourensis (Matthew), Haut and Crarxe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, pp. 93,
95, and 233, Pl. IV, figs. 18-20. (Discussed.)

Protorthis latourensis (Matthew), Waucorr, 1905, Proc. U. 8. Nat. Mus., vol. 28, pp. 282-283. (Original description,
Matthew, 1886, pp. 42-48, copied, and species discussed as on p. 742.)

The original description by Matthew follows:

Valves narrowly semicircular, broader than long, flat; umbones low; greatest thickness in the posterior third;
hinge line shorter than the width of the shell.

Dorsal valve with a distinct median depression extending from the umbo to the front margin, and with low
ridges diverging from the beak toward the lateral third of the front of the valve. Umbo not elevated above the hinge
area, which is exceedingly narrow or absent. Hinge line with two sharp slightly projecting teeth near the umbo
(crura?).

Ventral valve with a narrow median ridge extending two-thirds of the length of the valve toward the front mar-
gin; also with a fainter ridge on each side diverging toward the lateral third of the border of the valve; umbo very

742 CAMBRIAN BRACHIOPODA.

low; hinge area perceptible, but very narrow, longitudinally striated, and having a minute tooth on each side of the
very narrow and small foraminal opening.

Surface ornamented with about forty or fifty fine, faint, radiating stricz; those of the middle fifth are close, con-
tinuous, and straight; a few on each side of these are divergent, while those near the back of the shell are fainter,
closer than the last, and moderately arched outward toward the lateral borders. The surface of the valves is also
marked by very fine but distinct concentric striz, and at somewhat regular intervals by about twelve more distinct
lines ofgrowth. The concentric striz are usually as distinct as the radiating. Casts of the interior of the valves exhibit
a smooth surface with some irregular, sinous, radiating striz.

Length, 7 mm.; width, 11mm. Length of hinge line, 8 mm.

Observations.—Doctor Matthew kindly sent me the typical specimens of this species, and
from them and specimens in the collections of the United States National Museum sufficient
data were obtained to clearly show that the species belongs to Protorthis and not Kutorgina.
In figure 3b, Plate XCIX, the free spondylium is present. As far as known, the characters
of the area, teeth, and free spondylium are the same as in P. billingsit. The smooth
casts suggest Kutorgina [Hall and Clarke, 1892c, Pl. IV, figs. 18-20], but the ribbed shells
recall P. qguacoensis, and the area with open delthyrium and free spondylium places the species
in Protorthis. Its very fine surface ribs differentiate P. latowrensis from all other described
species.

The form described by Matthew [1886, p. 43, Pl. V, fig. 19] as ‘‘ Kutorgina pterineoides” is
not taken up in this monograph. The species is represented by one distorted specimen which
may not even be a brachiopod.

FoRMATION AND LOCALITY.—Middle Cambrian: (301w) Shales of Division 1c2 of Matthew’s section; (308h) shales
of Division 1cl of Matthew’s section; and (301g) shales of Division 1c of Matthew; all at Portland (now part of the
city of St. John), St. John County, New Brunswick.

PROTORTHIS QUACOENSIS (Matthew).
4 Plate XCIX, figures 2, 2a-e.

Orthis quacoensis MarruEw, 1886, Trans. Roy. Soc. Canada, vol. 3, sec. 4, No. 4, pp. 43-44, Pl. V, figs. 20, 20a-c. (De-
scribed and discussed. The two specimens represented by figs. 20-20a and 20b-20c are redrawn in this
monograph, Pl. XCIX, figs. 2e and 2b, respectively.)

Orthisina? quacoensis Marramw, 1891, Trans. Roy. Soc. Canada, Ist ser., vol. 8, sec. 4, No. 6, p. 181. (Mentioned and
generic reference changed.) é

Protorthis quacoensis (Matthew), Haun and CrarKe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, p. 232,
Pl. VIIA, fig. 21. (Changes generic reference.)

Billingsella quacoensis (Matthew), Scuucuerr, 1897, Bull. U.S. Geol. Survey No. 87, p. 159. (Merely changes generic
reference.) t :

Protorthis quacoensis (Matthew), Waucorr, 1905, Proc. U. S. Nat. Mus., vol. 28, pp. 284-285. (Original description,
Matthew, 1886, pp. 43-44, copied and species discussed as below.)

The original description by Matthew follows:

A small species. Subquadrate to semielliptical in outline, broader than long, widest near or at the hinge line,
which is not produced; moderately convex, highest in the posterior third, flattened toward the front and sides.
Umbones not prominent,

The dorsal valve rises rapidly from the hinge line, and has but a narrow, flattened space at the angles. It is about
one-third as high as‘it is long. The hinge plate has a narrow area, which is striated lengthwise, and bears two tooth-
like processes close to the umbo, the point of which is bent down to the hinge line.

The ventral valve is somewhat more elevated than the dorsal.» Hinge area triangular, sloping backward to the
umbo, and bearing fine strie parallel to the hinge line. Umbo elevated above the hinge line to a height fully equal to
one-third of the length of the valve. Foramen (delthyrium) large, truncate-pyramidal in outline.

Surface of the valves ornamented by about twenty rounded plice, radiating (in the ventral valve) from the edge
of the hinge area; opposite the foramen (delthyrium) and not from the beak alone; those on the middle fifth of each
valve are crowded together; those outside of these are more prominent, and are continuous from the umbo; those
toward the hinge line are faintly marked and widely separated. The radiating plicze do not (or rarely) increase by
bifurcation. Both valves bear numerous concentric striz and are also marked by a few distinct squamose lines of growth.

The mold or cast of the interior of the valves of this species is nearly smooth, or is marked by faint radiating
striee; the margin of the mold, however, often exhibits a crenulated appearance corresponding to the plicz of the
outer surface. There is a wide, smooth median depression at the top of the mold of the dorsal valve, near the umbo,

Length of the valve in 0. quacoensis, 5 mm.; width, 8 mm.

BILLINGSELLID. 743

Observations.—Doctor Matthew very kindly sent me his types of this species and I have
had a number of drawings made from them. A glance at them and the illustrations of P.
billingst shows that the two species are quite distinct and that P. quacoensts is unlike any other
shell referred to the genus.

As far as seen, the free spondylium of the ventral valve is short; the teeth are clearly shown
in the cast. The pseudocruralium of the dorsal valve is much more clearly defined than in
P. billingsi (pe, Pl. XCIX, figs. 2c and 2e), the area is higher (Pl. XCIX, fig. 2c), and traces of
the adductor muscle scars are preserved (Pl. XCIX, fig. 2d).

FoRMATION AND LOCALITY.2—Middle Cambrian: (301m [Matthew, 1886, p. 44]) Shale of Division 1c of Matthew’s
section on Porters Brook, St. Martins; (8b) shale at the base of the Paradowxides zone, at the head of Seeley Street, St.
John; (301w) shales of Division 1c2 of Matthew’s section at Portland (now a part of the city of St. John); and (301g

[Matthew, 1886, p. 44]) sandstones of Division 1c at Portland (now part of the city of St. John); allin St. foe County,
New Brunswick, Canada.

PROTORTHIS wWiINnGL Walcott.
Plate XCIII, figures 5, 5a-c.

Protorthis wingi Waucort, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 286. (Described and discussed as below as a new
species. )

General form transversely subelliptical. Surface marked by about 20 sharply ridged ribs,
with interspaces equal and usually greater than the width of the rib; shell with numerous
small and many larger and scattered punctz on the inner and outer surfaces. The largest
ventral valve has a length of 6 mm.; width, 9 mm.

Ventral valve convex, elevated at the umbo and beak; area high and divided midway by
a strong delthyrium, which is partly closed by a concave free spondylium (sp) as in P. 6bil-
lingsi; teeth strong, dental plates extended toward the center to unite and form the free
spondylium.

Dorsal valve slightly convex, with a broad median sinus that is usually bounded by one
or two large ribs; casts of the interior show a narrow area, broad delthyrium, and, opposite the
umbo, he cast of a small, broadly triangular, elevated area that probably seared as the car-
dinal process for the sHiidatenamt of the diductor muscles.

Observations.—This species is most nearly related to Nisusia (Jamesella) nautes (Walcott) ;
it differs, as far as known, in the character of the interior of the dorsal valve, the large puncte
scattered among the fine punctze, and the sharp-ridged ribs. One cast of an interior of a ven-
tral valve (PI. XII, fig. 5a) appears to indicate that the shell was without the free spondyl-
ium; it not infrequently occurs in Protorthis billings, (Hartt) that the free spondylium is
reduced to a narrow rim about the margin of the delthyrium and it may be that in this shell
it was absent.

The specific name is given in memory of Rey. Augustus Wing, whose extensive, and excel-
lent work in the vicinity of Swanton, Vermont, was utilized by Billings and Logan in the reports
of the Geological Survey of Canada.

ForRMATION AND LOCALITY.—Upper Cambrian: (28) Shales about 100 feet (30.5 m.) above the Olenellus horizon
south of Highgate Falls, 0.25 mile (0.4 km.) east of Swanton, Franklin County, Vermont. :

PRororRTHIS sp. undt. Walcott.

Protorthis sp. undt., Waucotr, 1905, Proc. U. 8. Nat. Mus., vol. 28, p. 286. (Described and discussed as below as
an undetermined species.)

Ventral valve convex, elevated at the umbo, apex incurved. The cast of the umbonal
cavity (pseudospondylium) indicates well-developed teeth and dental plates. On the cast six
radiating ribs occur in the distance of 1 millimeter; area about vertical. The surface of the
cast indicates that the interior layer of the shell was finely punctate. Length of valve 4.5
mm.; width, 5.5 mm.

a Matthew does not state which of the two localities, 301g and 301m, is the type, though he [1886, p. 82] locates the type specimen (Pl. XC1X,
fig. 2b) in Division 1c of his Etcheminian. -

744 CAMBRIAN BRACHIOPODA.

Only one specimen of a cast of a ventral valve of this shell was found. It suggests by its
convexity and surface some of the more convex forms of Protorthis quacoensis

FoRMATION AND LOCALITY.—Upper Cambrian: (75) Thin-bedded limestone just below the base of the Ordovician, ~
in the Tonto group; near the water’s edge at the mouth of Kanab Canyon, Grand Canyon of the Colorado, Arizona.

LOPERIA Walcott, subgenus of PROTORTHIS.

Protorthis (Loperia) Watcorr, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 287. (Characterized as below as a new sub-
genus.

Protorthis Een Waxcort, 1908, Smithsonian Misc. Coll., vol. 53, No. 4, Pl. XI, and pp. 142 and 147. (Classifica-
tion of subgenus.)

This subgenus is characterized by the form of the valves. The ventral valve is elevated
at the umbo and flat or slightly concave from the umbo to the margins; the dorsal valve is
strongly and regularly convex. The description of the type species, Protorthis (Loperia)
dugaldensis Walcott, includes that of the subgenus, as it is the only species thus far known.

The subgeneric name is given in recognition of the effective work of Mr. S. Ward Loper,
who collected the material representing this and many other Cambrian fossils in Cape Breton
and New Brunswick.

PROTORTHIS (LOPERIA) DUGALDENSIS Walcott.

\

me Plate XCIX, figures 5, 5a-j.

Protorthis (Loperia) dougaldensis Waucort, 1905, Proc. U. 8. Nat. Mus., vol. 28, pp. 287-288. (Described and dis-
cussed as below as a new species.)

General form rounded subquadrate. Hinge line straight and shorter than the greatest
width of the shell; cardinal extremities obtusely angular. Relative convexity of the valves
reversed as in Dinorthis pectinella [Hall and Clarke, 1892c, Pl. V, figs. 28-31] of the Ordovician
fauna. Surface of the valves with strong, simple, rounded ribs that increase by interpola-
tion; fine concentric striz and lines of growth, that sometimes form ridges, cross the ribs,
curving in the interspaces and over the ribs; these ribs are more prominent and numerous
(30 to 40) on the dorsal than on the ventral valve; on the latter the ribs are broad, with narrow
interspaces, and about 20 to 25 in number; casts of the exterior and interior surfaces have
numerous fine, thickly set, elevated papille that appear as the casts of the puncte in the layers
of the shell; on some specimens the papillz are cylindrical and elevated, which indicates that
they penetrated deep into the shell substance. All indications point to a punctate shell; in
all the material representing the species the shell has been removed by solution, only the casts
of the inner and outer surfaces remaining.

The largest ventral valve in the collection has a length of 18 mm., width 25 mm.; dorsal
valve, length 22 mm., width 27 mm.

Ventral valve elevated at the umbo and gently concave from the umbo to the front margin
and flat to the cardinal extremities. Area relatively low and overhanging the hinge line at an
angle of about 45°; it is divided midway by a broad delthyrium that is more or less closed
by a deeply concave plate, which is crossed by the transverse striae of growth of the area. The
concave plate appears to be identical in form and position with the free spondylum of the
genus Protorthis. A cast of the interior (fig. 5) shows very strong teeth and supporting dental
plates; the edges of the dental plates appear to be continuous with the concave plate or free
spondylium.

Dorsal valve strongly and regularly convex, with a slight flattening of the median line
and sometimes a shallow sinus. Casts of the interior show a strong area, with a triangular
delthyrium; the umbonal cavity is strongly outlined by the crural plates so as to form a pseudo-
cruralium; crura well developed, with clearly defined tooth sockets back of them. No traces
of a cardinal process have been seen in ten specimens showing fine casts of the area, delthyrium,
and umbonal cavity.

Observations.—This fine species is unique among Cambrian brachiopods in having a
depressed, flat, or convex ventral valve and strongly convex dorsal valve; in its punctate

BILLINGSELLIDA. 745

shell, free spondylium and absence of cardinal process, it is allied closely to Protorthis; the
depressed ventral valve and convex dorsal valve serve to distinguish it as a subgenus of Pro-
torthas.

The specific name is derived from Dugald Brook, Cape Breton.

FoRMATION AND LOcALITY.—Middle Cambrian: (10p) Sandstone just below the waterfall 0.25 mile (0.4 km.) from
the lower bridge in Division H2b of Matthew's (1903, p. 21] Htchemmmian, Dugald Brook, Indian River, eastern Cape
Breton, Nova Scotia.

(2u) Lowest beds exposed on the south side of Long Island, Kennebecasis Bay [Matthew, 1898a, pp. 124 and
127], St. John County, New Brunswick.

Subfamily BILLINGSELLIN 4 Schuchert.

Genus WIMANELLA Walcott.

Billingsella Waucort (in part) [not Hatt and CrarKe], 1905, Proc. U. 8. Nat. Mus., vol. 28, pp. 227-229. (Described
and discussed as on p. 749 (under Billingsella), but several of the species referred to the genus are now placed
under Wimanella.) j

Wimanella Waxcorr, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, pp. 98-99. (Discussed somewhat as below as a
new genus.)

Wimanella Waxtcorr, 1908, idem, vol. 53, No. 4, Pl. XI, and pp. 142 and 148. (Classification of genus.)

This genus is proposed for the smooth nonplicate species that I have heretofore referred
to the genus Billingsella. The generic description of Billingsella includes the characters of
Wimanella with the exception that the latter is a smooth shell but for the presence of concentric
strie and lines of growth. Wimanella represents the smooth, early stages of development
and Billingsella the later, mature plicate stage of development of this section of the Billingsellide.

Type.— Wimanella sumplex Walcott [1908d, p. 98].

Observations.—It is to be noted that Bullingsella plicatella Walcott (Pl. LX XXVI, figs. 3g
and 3h) includes some shells that are nearly smooth, and that B. highlandensis (Walcott) (Pl.
LXXXVII, figs. 4 and 4c) is very finely costate. The former species may be considered as
being in part a form intermediate between Billingsella coloradoensis (Shumard) and Wimanella
harlanensis (Walcott). I think, however, that the species with smooth shells should be grouped
under a generic head, as they indicate a marked phase in the evolution of the forms formerly
grouped under Billingsella.

The generic name was given in Coan of the valuable work of Dr. Carl Wiman of the
University of Upsala, on the geology and paleontology of the Baltic region.

WIMANELLA? ANOMALA (Walcott).

Plate LX X XVII, figures 1, la-e.

Billingsella? anomala Waxcort, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 250. (Described and discussed as below as a
new species.)

Shell subquadrilateral, with the dorsal valve transverse. On the ventral valve the cardinal
line slopes toward the beak at an angle of from 15° to 20°, while in the dorsal valve it is nearly
straight. The greatest width of the valves is about the middle of the shell. Owing to com-
pression and consequent distortion there is considerable variation in the relative proportions of
length and breadth. The cardinal angle is acute, in some instances extending out some distance
beyond the widest portion of the shell, resembling in this respect the cardinal angles of some
of the Strophomenide. All of the specimens are so compressed in the shale that little is
preserved of their natural convexity. A low, broad, mesial smus occurs on the dorsal valve,
and there is a slight flattening of the anterior central portion of the ventral valve.

The surface is marked by fine, radiating striz, that are mcreased in number toward the
front by the addition of interstitial strie, giving a fasciculate appearance to the surface. The
radiating striz are crossed by concentric lines of growth and fine striz. The surface as described
occurs in one specimen, all other specimens being nearly smooth. This, however, may arise

746 CAMBRIAN BRACHIOPODA.

from maceration and flattening out of the surface characters by compression. ‘The interior of
the shell appears to have been covered by minute puncte.

The largest specimen of the collection has a transverse diameter of 14mm. The average
size of the ventral valve is about 8 mm. in height by 8 mm. in width.

Cardinal area about one-fifth the height of the shell. It is marked by transverse striz of
growth that cross it parallel to its base. Delthyrium rather broad. No traces of the deltid-
ium haye been observed. Cardinal area of the dorsal valve short. It is divided midway by
a strong delthyrium. Nothing is known of the interior characters except the presence of a short
crura in the dorsal valve. ;

Observations —This shell occurs quite abundantly m the very fine, buff-colored, argilla-
ceous shales of the Coosa Valley Cambrian section. There is some doubt as to its surface char-
acters, as only one specimen found in the same beds has traces of radiating strize, and these
may be from the interior radiating lines. All others appear to be nearly smooth. Its strongest
character is the extension of the cardinal angle. Owing to the imperfection of the material the
generic reference is doubtful.

The species was anomalous while under Billingsella, to which it was first referred, hence
the specific name.

FORMATION AND LOCALITY.—Middle Cambrian: (90) Conasauga (‘‘Coosa”) shale, on Edwards farm, near Craigs
Mountain, about 10 miles (16.1 km.) southeast of Center, Cherokee County, Alabama.

WIMANELLA HARLANENSIS (Walcott).

\

Plate LX X XVII, figures 5, 5a—-d.

Billingsella harlanensis Watcott, 1905, Proc. U. 8. Nat. Mus., vol. 28, p. 236. (Characterized and discussed as below
as a new species.) j

The general form and convexity of this shell is similar to that of Billingsella plicatella
Walcott. It differs in havig a nearly smooth surface marked only by fine concentric striz
and a few traces of narrow, sharp radiating cost. The interior of the ventral valve has very
strong main vascular smuses and a deep, sharply defined, tripartite umbonal area opposite the
delthyrium; the tripartite area is much like that in Billingsella coloradoensis (Shumard) and
B. exporrecta (Linnarsson). The main vascular sinuses pass directly back across the ridge in
front of the tripartite area and occupy the two lateral divisions of the area. The interior of the
dorsal valve represented in figure 5a shows an abnormal arrangement of the vascular markings
and muscle scars.

The specific name is derived from Harlan Knob, Tennessee.

FoRMATION AND LOCALITY.—Middle Cambrian: (107) Limestone in Bull Run, northwest of Copper Ridge [Keith,
1896b, areal geology sheet], 11 miles (17.6 km.) northwest of Knoxville, Knox County; and (121) Rogersville shale,
road just east of Harlan Knob, 4 miles (6.4 km.) northeast of Rogersville | Keith, 1905, areal geology sheet], Hawkins County;
both in Tennessee.

WIMANELLA INYOENSIS Walcott.

Text figures 63A-B, page 747.

Wimanella inyoensis Waucott, 1908, Smithsonian Mise. Coll., vol. 53, No. 3, p. 99, Pl. X, fig.4. (Described as below
as a new species. Fig. 4 is copied in this monograph as fig. 63A.)

This species is represented by numerous specimens in the form of casts in a calcareous
saudstone. All of the shells are more or less compressed and distorted. Some of those best
preserved indicate that the general outline was transverse. A specimen 6 mm. in length has a
width of 7mm. The two specimens illustrated (figs. 63A and 63B) occur on the same fragment
of rock and illustrate fairly well the difference in outline; it may be that figure 63A is the
narrow ventral valve and figure 63B the broader dorsal valve.

BILLINGSELLID. 747

The most striking feature is the presence of two strong radiating ridges that originate near
the beak and extend forward nearly to the frontal margin. These ridges may be the casts of
the main vascular sinuses or it may be that they represent
ridges on the exterior of the shell, one on each side of the
shallow median sinus. At present, with the material before
me, I am inclined to the view that they represent the casts
of sinuses and hence the provisional generic reference to
Wimanella.

Nothing is known with certamty of the outer surface
or of the substance of the shell. The interior casts and the
matrices of the casts show two strong radiating ridges, the
shell substance having apparently been removed and its Ficure 63.—Wimanella inyoensis Walcott. A, B,

: oO : Narrow and broad forms showing the two strong
place lost by the compression of the sediment before its Hidets onthe ont Lavan e ean Tine

consolidation. the main vascular sinuses (U. S. Nat. Mus. Cat.
Nos. 52255a and 52253b, respectively).

cific See ee Ree ec - Cali )
The specific name is derived from Inyo County, Cali Te tien pc cA ATS.

fornia. Lower Cambrian, Inyo County, California. Figure
‘ 63A is copied from Walcott [1908d, Pl. X, fig. 4].
FORMATION AND LOCALITY.—Lower Cambrian: (8b) Limestones in It represents the type specimen.

Tollgate Canyon, about 15 miles (24.2 km.) east of White Pine, White
Mountain Range, Inyo County, California.

WIMANELLA SAFFORDI (Walcott).

Plate LXX XVII, figures 7, 7a.

Billingsella saffordi Waucott, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 244. (Described and discussed as below as a
new species. )

General outline of ventral valve subsemicircular and of dorsal valve transversely broad
oval; greatest width of valves at about the center; hinge line straight and a little shorter than
the greatest width of the shell. A typical ventral valve has a length of 9 mm., width 9 mm.
Dorsal valve, length 10 mm., width 12 mm. Biconvex, the ventral valve being more elevated
at the umbo than the dorsal. Surface, so far as known, smooth or marked by concentric
striz and lines of growth.

Ventral valve with umbo curving over and terminating in the small apex that incurves a
little over the area; area about one-half the elevation of the valve; a broad delthyrium is partly
covered by a convex deltidium; casts of the interior indicate a low, tripartite pseudospondylium
and one cast shows strong main vascular sinuses extending from the lateral divisions of the
pseudospondylium nearly to the front margin. Dorsal valve with low area and small pseudo-
cruralium; the casts are too imperfect to show any other details.

Observations —This species occurs in the same region as Wimanella harlanensis (Walcott) and
also has asmooth shell; it differs in being of equal length and breadth and in having less stronely
marked imterior characters.

The specific name is given in recognition of the work of Mr. J. M. Safford upon the geology
of Tennessee.

ForRMATION AND LOCALITY.—Middle Cambrian: (14a) Sandstone of the Rome formation, along First Creek Gap,
4 miles (6.4 km.) north-northeast of Knoxville [ Keith, 1905, areal geology sheet], Knox County, Tennessee.

WIMANELLA SHELBYENSIS Walcott.
Plate Il, figures 9, 9a.
Wimanella shelbyensis Watcotr, 1908, Smithsonian Misc. Coll., vol. 58, No. 3, p. 100, Pl. X, fig. 3. (Described and
discussed as below as a new species. Fig. 3 is copied in this monograph, PI. II, fig. 9.)

All the specimens representing this species in the collection are flattened in the shale to
such an extent that very little of the original convexity of the shell is retained, and only the
impression of the shell remains, as the shell substance has been entirely removed, probably by
solution. The general form of this species resembles very closely that of Billingsella ? appalachia.

748 CAMBRIAN BRACHIOPODA.

The casts show a strong cardinal area on the ventral valve, with a broad delthyrium, but not a
pseudodeltidium; the love valve has a narrow cardinal area with a broad open delthyrium.
The exterior surface is marked by fine concentric lines and a few stronger varices of growth.
A small ventral valve has a length of 8 mm., with a width of 10mm. A pneer one has a length
of 18 mm.; width, 22 mm. A small dorsal valve has a length of 10 mm.; width, 13 mm.; and
the largest dorsal valve in the collection has a length of 19 mm.; width, 25 mm.
None of the specimens show any traces of vascular or muscular markings; in this respect
resembling Wimanella? anomala (Walcott) (Pl. LX: X XVII) and Billingsella? appalachia Walcott
(PI. LXX XVII).

This species appears to be the Lower Cambrian representative of W.? anomata of the Middle
Cambrian, differing from the latter in having rounded cardinal angles instead of the acute
projecting angles so characteristic of W.? anomala. Billingsella? appalachia has the same general
formas W. shelbyensis, but the latter differs from it in having a smooth surface and in the absence
of all traces of radiating ribs.

It more nearly resembles Wimanella simplex Walcott (Pl. LXXXIX, fig. 2). It differs
from the latter in being more transverse, and the cast of the umbonal cavity is relatively smaller.

It is a curious fact that in all the species of Wimanella mentioned there is no trace of a
vascular marking or muscle scar. All the species occur in argillaceous shale, and none of them
preserve the shell substance. The shells appear to have been macerated and removed by
solution, leaving only a cast of the compressed inner or outer surface of the valve.

The specific name is derived from Shelby County, Alabama.

ForMATION AND LOCALITY.—Lower Cambrian: (17b) Shale in Rome (‘‘ Montevallo”) formation, 4 miles (6.4 km.)

south of Helena; and (56c) shale in Rome (‘‘Montevallo”) formation along road just north of Buck Creek, 1.125 miles
(1.8 km.) northeast of Helena; both in Shelby County, Alabama.

we WIMANELLA SIMPLEX Walcott.
Text figure 64; Plate LXXXIX, figures 2, 2a-e.

Wimanella simplex Waxcott, 1908i, Smithsonian Misc. Coll., vol. 53, No. 3, p. 101, Pl. X, fig. 2. (Discussed as below
as anew species. Fig. 2 is copied in this monograph, Pl. LXX XIX, fig. 2.)

The general form of this species is much like that of Billingsella coloradoensis,except that
the beak of the ventral valve rises above the hinge line, much as in B. highlandensis (Pl. LX X XVII,
figs. 4,4a). The surface of W. simplex appears to be smooth except for
a few concentric lines of growth. Nothing is known of the interior
except what is shown by the cast of the umbonal cavity. A crushed
specimen with the two valves flattened out (fig. 2e) indicates that the
beak of the dorsal valve was slightly elevated above the hinge line; it
is probable that figure 2 represents a dorsal valve. All the specimens
A ; are flattened in shale, and the shell substance has been removed by solu-
IGURE 64.— Wimanella simplex a See 2 5 s
Walcott. Interior ofacom- tion. The material is unsatisfactory, but as it represents a species of

pressed dorsal valve. Found the smooth type from a known horizon in the Middle Cambrian, it is
in Locality 35c, in a drift

plock of Lower Cambrian illustrated and given a specific name.
shale on Mount Bosworth, J
British Columbia (U.S. Nat. FoRMATION AND LOCALITY.—Lower Cambrian: (4v) About 200 feet (61 m.) above the

Mus. Cat. No. 51407). unconformable base of the Cambrian and 7/5 feet (22.9 m.) above the top of the quartzitic sand-

stones in a shale which corresponds in stratigraphic position to shale No. 6 of the Dearborn

River section [ Walcott, 1908f, p. 202], Gordon Creek, 6 miles (9.6 km.) from South Fork of Flathead River; and (4q and

4w) about 315 feet (96 m.) above the unconformable base of the Cambrian and 190 feet (57.9 m.) above the top of the

quartzitic sandstones in a shale which corresponds in stratigraphic position to shale No. 6 of the Dearborn River

section [Walcott, 1908f, p. 202], on Youngs Creek, about 5 miles (8 km.) from its junction with Danaher Creek; both
in the Ovando quadrangle (U. 8S. Geol. Survey), Powell County, Montana.

(35e) Drift blocks of siliceous shale supposed to have come from the Mount Whyte formation [Walcott, 1908f,

p. 214], found on the south slope of Mount Bosworth, a short distance northwest of the Canadian Pacific Railway track

between Stephen and Hector, eastern British Columbia, Canada.

BILLINGSELLIDE. 749

Genus BILLINGSELLA Hall and Clarke.e

Billingsella Haut and CuarKs, 1892, Hleventh Ann. Rept. State Geologist New York for 1891, p. 2738. (Described.)

Billingsella Hatt and CLrarKe, 1892, Forty-fifth Ann. Rept. New York State Museum for 1891, p. 589. (Copy of
preceding reference.)

Kutorgina Hatt and Crarke [not Watcort], 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, pp. 90-94. (Copies
Walcott’s description, 1886b, pp. 101-102, and discusses genus, but description and discussion also include refer-
ence to specimens now referred to Billingsella, Protorthis, Micromitra, Micromitra (Paterina), and Micromitra
(Iphidella).)

Billingsella Hatt and Cuarke (in part), 1892, idem, pp. 230-231. (Described and discussed as a new genus. The
genus as described also included species now referred to Nisusia.)

Billingsella Hall and Clarke, ScHucHERT (in part), 1897, Bull. U. S. Geol. Survey No. 87, p. 158. (Characterized
and discussed. The genus Protorthis is placed as a synonym of Billingsella, and among the species referred to
the latter genus are species belonging with both Protorthis and Nisusia.)

Billingsella Hall and Clarke, Waucorr (in part), 1905, Proc. U. 8. Nat. Mus., vol. 28, pp. 227-229. (Described and
discussed essentially as below. Species that are now referred to Wimanella were included in the genus.)
Billingsella Hall and Clarke, GRaBav and Suimer, 1907, North American Index Fossils, vol. 1, p. 210. (Described.)
Billingsella Hall and Clarke, Watcort, 1908, Smithsonian Misc. Coll., vol. 53, No. 4, Pl. XI, and pp. 142 and 148.

(Classification of genus. )

Shell subquadrate or subsemicircular in outline. Contour unequally biconvex or plano-
convex. Shellimpunctate. Surface striate or plicate. Ventral valve with the greatest con-
vexity; cardinal area moderately high, slightly inclined outward; delthyrium covered by a
convex plate which in the type species B. coloradoensis has a minute perforation near the apex;
teeth well developed, with dental plates extending to the bottom of the umbonal cavity and
forming the sides of a small area opposite the delthyrium, where the pedicle muscle was probably
attached. In the dorsal valve the cardinal area is strongly inclined, but less than 90° to the
plane of the valve. The delthyrium is partly covered by a convex chilidium, or it may be
altogether absent. Cardinal process single. A rudimentary spondylium is indicated for B.
dice. Shell structure dense, minutely granular, with minute pores scattered through the
calcareous lamellee.

Type.—Orthis coloradoensis Shumard.

Observations —Hall and Clarke [1892¢e, p. 230] founded the genus on “‘Orthis pepina”’ Hall,
which is a synonym of “‘Orthis coloradoensis’”’ Shumard. The material from the limestones of
‘Texas in the United States National Museum shows the form of the teeth in the ventral valve,
also the deltidium and the minute perforation near its apex. Hall and Clarke [1892c, p. 230]
state in their diagnosis that “im rare instances (it) may be minutely perforated at the apex,” but
do not name the species in which the perforation occurs or where the specimens showing it are
to be found. All the species known to me are biconvex or plano-convex; none are concayo-
convex as defined by Hall and Clarke [1892¢, p. 230].

The genus is essentially orthoid, but it differs in the presence of the arched deltidium and
its general aspect from typical examples of the Orthide, and its shell is of a dense, nonfibrous
structure.

a The synonymy for this genus does not give a complete record of the various genera under which the species now included in Billingsella were
formerly placed; it gives only those references in which the genus is discussed or described. To complete the record the following mere generic
references are listed: \

Orthis Barrande [1848, p. 203]. Orthis Walcott [1887, p. 190].
Orthis Shumard [1860, p. 627). Orthis Oehlert [1889, p. 1139].
Orthis Hall [1863, p. 134; 1867, p. 113). Orthis ? Walcott [1891a, p. 612).
Orthis Davidson [1868, p. 314; 1869, p. 230). Orthisina Walcott [1891a, p. 613].
Orthis Linnarsson [1876, pp. 10, 12, and 13]. Clitambonites (Gonambonites) Matthew [1895b,
Orthis Barrande [1879b, Pl. U-XII, fig. 11). p. 267].
Orthis Whitfield [1882, p. 170]. Orthis Wallerius [1895, p. 66].
' Orthis? (Orthisina?) Hall [1883, Pl. XX XVII, figs. Orthis Pompeckj [1896b, p. 513].

16-19]. ‘ Orthis (Billingsella) Sardeson [1896, p. 96].
Orthis Kayser [1883, p. 35]. Clitambonites Schuchert [1897, p. 184].
Kutorgina Walcott [1884b, p. 18). Billingsella Walcott (1899, p. 450).

Orthisina Whitfield [1884, p. 144]. Billingsella Matthew [1903, p. 148).
Orthis ? Walcott [1886b, p. 119]. Orthis (Plectorthis) Walcott [1905a, p. 270).
Orthisina Walcott [1886b, p. 120]. Billingsella Walcott [1908d, pp. 101 and 102).

750 CAMBRIAN BRACHIOPODA.

Of the species referred to the genus, Billingsella exporrecta is one that departs from the
typical species in the absence of a strong convex deltidtum, and B. dice has a rudimentary
spondylium in the ventral valve, a character not developed in other species of the genus,

For the relations of Billingsella to Nisusia, see remarks under the latter genus, page 725.

The genus was named in honor of Mr. E. Billings.

BILLINGSELLA ? APPALACHIA Walcott.
Plate LXX XVII, figures 2, 2a-b.
Billingsella? appalachia Waucorr, 1905, Proc. U. 8. Nat. Mus., vol. 28, p. 231. (Described as below as a new species.)

The outline of the dorsal valve is rounded subquadrate. The height and width of the
ventral valve are about the same. Dorsal valve slightly transverse.

The surface is marked by round, very fine, radiating cost, and lines of growth, with very
fine interstitial concentric striz. i

The average ventral valve is about 10 mm. in height, with an equal width. The largest
shell observed was a ventral valve with a width of 14 mm.

Cardinal area of the ventral valve rather low. It is divided midway by a rather strong
delthyrium.

Observations —In form and size this shell is much like that of Wimanella? anomala. It
differs in its strongly marked surface characters. All the specimens are flattened in the shale
and nothing is known of the interior characters.

FoRMATION AND LOCALITY.—Middle Cambrian: (121) Rogersville shale, road just east of Harlan Knob, 4 miles
(6.4 km.) northeast of Rogersville [Keith, 1905, areal geology sheet], Hawkins County, Tennessee.

This species is somewhat doubtfully identified from the following locality:

Middle Cambrian: (14) Limestones overlying the sandstones of the Rome formation, near the wagon road and
in a quarry near the railroad track, 7 miles (11.2 km.) southwest of Rome [Hayes, 1902, historical geology sheet], Floyd
County, Georgia.

BIULINGSELLA BIVIA nN. sp.
\

> Text figures 65A-C.

The specimens of this species are preserved in a sandstone and usually occur in the form
of flattened casts. The valves are transverse in outline, equally convex, and have their great-
est width at the hinge line. The beak of the ventral valve projects over the hinge line and

A

FIGURE 65.—Billingsella bivia n. sp. A, A’, Top and side view of exfoliated dorsal valve, the type specimen, from Locality 141, Lower Cambrian,.

near Resting Springs, Inyo County, California (U.S. Nat. Mus. Cat. No.52254a). B, Enlargement (Xabout 6) of the outer surface, with strong and

fine radiating ribs, ofashell from Locality 14p, Lower Cambrian, near Resting Springs, Inyo County, California (U. S. Nat. Mus. Cat. No. 51404).
C, Ventral valve from Locality 141, Lower Cambrian, near Resting Springs, Inyo County, California (U.S. Nat. Mus. Cat. No. 52254b).

is flattened so that it barely rises above the plane of the margins of the shell. The hinge

line of the dorsal valve is broadly rounded, and most of the specimens show a fairly well -

marked mesial sinus. A dorsal valve preserving the outer surface shows it to have been
covered by coarse, radiating coste, each of which is marked by a number of minute radiating
ridges.

The species is closely related to Billingsella highlandensis (Walcott), but differs from that
species in being more transverse in outline, in the absence of a concentric striation, and in
other details of surface sculpture, and in the prominence of the mesial sinus.

ForMATION AND LocALITy.—Lower Cambrian: (141) Sandstones about 2,800 feet (853 m.) below the Middle
Cambrian in a horizon correlated with No. 2) of the Silver Peak group of the Waucoba Springs section [ Walcott, 1908f, p.

BILLINGSELLIDA. 751

187], in the pass about 7 miles (11.2 km.) east of Resting (Freshwater) Springs; and (14p) sandstones near Resting (Fresh-
water) Springs; both in the southwest corner of T. 21 N., R. 8 E., on Amargosa River, in the southeastern part of Inyo
County, California.

BILLINGSELLA COLORADOENSIS (Shumard).

“Lv Text-fieures 6, page 299, 66; Plate LXXXYV, figures 1, la-z.

Orthis coloradoensis SHuMARD, 1860, Trans. Acad. Sci. St. Louis, vol. 1, p. 627. (Described as a new species.)

Orthis pepina Haut, 1863, Sixteenth Ann. Rept. New York State Cab. Nat. Hist., pp. 134-135, Pl. VI, figs. 23-27.
(Described and discussed as a new species.)

Orthis pepina Hat, 1867, Trans. Albany Inst., vol. 5, p. 113, Pl. I, figs. 23-27. (Copy of preceding reference.)

Orthis pepina Hall, WuirrieLp, 1882, Geology of Wisconsin, vol. 4, pt. 3, pp. 170-171, Pl. I, figs,4and5. (Described
and discussed.) ;

Orihis? (Orthisina?) pepina Hau, 1883, Second Ann. Rept. State Geologist New York for 1882, Pl. XX XVII, figs.
16-19. (Figs. 16-19 are copied from Hall, 1863, Pl. VI, figs. 23, 25, 24, and 26, respectively.)

Billingsella pepina (Hall), Hatt and Curarxks, 1892, Eleventh Ann. Rept. State Geologist New York for 1891, Pl. VIII,
figs. land 2. (No text reference.)

Billingsella pepina (Hall), Haun and CrarKe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, p. 230, Pl. VII,
figs. 16-19; Pl. VIIA, figs. 7-9. (Mentioned in description of genus. Pl. VII, figs. 16-19, are copied from
Hall, 1863, Pl. VI, figs. 23, 25, 24, and 26, respectively. Figs. 8 and 9 are copied from figs. 1 and 2, respec-
tively, of the preceding reference.)

Orthis (Billingsella) pepina (Hall), SarpEsoNn, 1896, Bull. Minnesota Acad. Nat. Sci., vol. 4, No. 1, pt. 1, p. 96. (New
localities mentioned.)

Billingsella coloradoensis (Shumard), ScoucnHErt, 1897, Bull. U. 8. Geol. Survey No. 87, p. 158. (Merely changes

‘generic reference. ) ;

Billingsella coloradoensis (Shumard), Watcott, 1899, Mon. U.S. Geol. Survey, vol. 32, pt. 2, pp. 450-451, Pl. LXI,
figs. 1, la-d. (Discussed and characterized. Figs. 1, la-d are copied in this monograph, Pl. LXXXYV, figs.
la, 1g, lw, lo, and 1t, respectively, figs. lw and 1t being slightly altered.)

Billingsella coloradoensis (Shumard), Waucorr, 1905, Proc. U. S. Nat. Mus., vol. 28, pp. 231-234. (Described and
discussed essentially as below.)

Billingsella coloradoensis (Shumard), GRaABAvU and Summer, 1907, North American Index Fossils, vol. 1, p. 210. (Char-
acterized.)

Shell usually transverse but in many examples the ventral valve is longer than wide.
The general outline is irregularly subquadrate to subsemicircular. On the ventral valve the
hinge line slopes toward the beak at a low angle while in the dorsal valve it is nearly straight.
In some individuals the greatest width is at the hinge line.
In others it is at about the middle. There is considerable
variation in the relative proportions of length and breadth.

The ventral valve is slightly more convex than the
dorsal. The degree of convexity of the two valves varies

FIGURE 66.—Billingsella coloradoensis (Shumard).

considerably in specimens from different localities. Some of Posterior view of a ventral valve showing
the ventral valves from beds at Franconia, Minnesota, and pedicle opening in the deltidium; from Local-
h Thy ills & T i Wi 6 ] ity 70, Upper Cambrian, on Morgans Creek,
the young shells from Trempealeau, Wisconsin, are strongly Texas (U, S. Nat, Mus. Cat, No. 34777),
convex.

A low, broad, median sinus occurs on nearly all specimens of the dorsal valve, being straight
in the young shells, and occasionally a shallow sinus is clearly defined on the ventral valve.
It is quite rare to find a well-marked median fold on the ventral valve.

The surface is marked by sharply rounded, radiating coste crossed by fine concentric
lines of growth and very fine, slightly undulating, concentric striz. The size and sharpness of
the radiating ribs vary greatly in specimens from the same bed at the typical locality in Texas.
Shells occur with strong rounded costx, and no traces of fine elevated lines between, whereas
others show from one to four or more lines that start at varying distances from the beak. The
imbricating lines of growth give a concentrically ridged aspect to some shells, though others
are nearly smooth from beak to frontal margin. The increase in the number of ribs is by
interpolation, not by bifurcation.

There is considerable variation in the size of the shell. The largest specimens from Texas
have a transverse diameter of 19 mm., with a length of 14 mm. for the dorsal valve, and about
18 mm. for the ventral valve. Specimens of the ventral valve from the Yellowstone National
Park have a length of 14 mm. with a width of 15 mm.

752 CAMBRIAN BRACHIOPODA.

Cardinal area of ventral valve moderately high. It is marked by transverse striz of
growth that cross it parallel to its base and arch over the convex deltidium. The plane of the
area extends backward at an angle of about 10° to the plane of the margin of the shell. The
delthyrium is strong and covered by a convex deltidium, the front margin of which arches
back about one-fifth the length of the delthyrium. The deltidium is marked by concentric
strie of growth and fine radiating lines and a minute perforation near its apex. The cardinal
area of the dorsal valve is short as compared with the ventral valve. It extends backward
at an angle of about 45° to the plane of the margin of the valve. It is divided midway by a
strong delthyrium which is covered for about half its distance by a convex chilidium.

In the interior of the ventral valve the hinge teeth appear to be supported by dental
plates that extend down to the bottom of the valve and bound the tripartite umbonal space
opposite the delthyrium into which the vascular sinuses extend on each side of the diductor
muscle impressions, or their path of advance. The traces of the vascular system are confined
to the main vascular trunks which extend forward nearly to the front margin, where in some
examples they are bifurcated. The inner branch extends in toward the median line, disap-
pearing in the numerous radiating depressions near the margin. The lateral branches appear
to connect with the peripheral canal that arches about the space probably occupied by the
ovarian areas, between itself and the main vascular trunks. The space for the attachment of
the muscles between the main vascular trunks appears to have been quite large, extending for-
ward to the anterior fifth of the length of the valve, but no subdivisions indicating the points
of attachment of the different muscles have been detected. The pedicle muscles were probably
attached to the elevated, posterior portion of this central area. In some casts this posterior
area is scarcely elevated above the plane of the interior. In others it is fairly prominent.

Tn the interior of the dorsal valve the interior of the deltidial cavity supports a small well-
developed cardinal process or callosity, and a slight narrow median ridge occurs just in advance
of the deltidial cavity. The crura are short and well defined, with relatively shallow dental
sockets beside them.. The cardinal process and crura vary in size and length in shells from
the same locality. The only traces of the muscle scars observed show the anterior adductor
impressions. The vascular trunks of the dorsal valve diverge from the central line about the
center of the shell, after passing around the adductor muscle impressions.

Observations.—The average size of the typical specimens from Texas is from 10 to 14 mm.
in length for the ventral valve, the width being about the same. At one locality on Morgans
Creek several dorsal valves were found that have a width of 18 mm., with a length of 12 mm.
This may possibly indicate a variety or distinct species, but with the material in the collec-
tion it is impossible to determine definitely. The shells from the upper Mississippi Valley in
Wisconsin and Minnesota average about the same size as the typical forms from Texas. The
young shells are much more convex. The material from the Gallatin Range, Yellowstone
National Park, is also much like that from Texas, but that from the limestone near Malade,
Idaho, though it contains typical shells, also has specimens as large as those from Morgans
Creek, Texas.

Billingsella major differs from B. coloradoensis in the character of the surface striation,
also in its larger size. Billingsella plicatella is a uniformly smaller and more convex shell, and
also has distinct surface characters. The same is true of B. striata.

FoRMATION AND LOCALITY.—Lower Ordovician: (339 [Sardeson, 1896, pp. 95 and 96]) Oneota dolomite, Stili-
water, Washington County, Minnesota.

Upper Cambrian: (302q) About 1,000 feet (305 m.) above the quartzitic sandstones in the “ Yogo limestone (Devono-
Silurian)” of W. H. Emmons [1907, p. 34], on Rock Creek, Phillipsburg quadrangle (U. S. Geol. Survey), Granite
County; (302r) same horizon as Locality 302q, near Princeton, Phillipsburg quadrangle (U.S. Geol. Survey), Granite
County; (302f) limestone in upper part of the Gallatin formation, north side of Elk Pass, between Buffalo and Slough
Creeks, Yellowstone National Park, Livingston quadrangle (U. S. Geol. Survey); (147a) limestone in Spring Hill
Canyon, west side of the Bridger Range, Gallatin County; and (155) limestone north of Hast Gallatin River, near
Hillsdale, Threeforks quadrangle (U. S. Geol. Survey), Gallatin County; all in Montana.

(302p) Middle limestone of the Deadwood formation near the summit of the Owl Creek Mountains, 18 miles (29
km.) southwest of Thermopolis, Fremont County; (302g) limestone on the north slope of Crowfoot Ridge south of the

BILLINGSELLID. 753

Gallatin Valley, Gallatin quadrangle (U. S. Geol. Survey), Yellowstone National Park; and (302h) limestone on the
divide between Panther Creek and West Gallatin (Gallatin) River, Gallatin quadrangle (U. S. Geol. Survey), Yel-
lowstone National Park; all in Wyoming.

(4y, 5a, 5c, and 54t) Limestones about 250 feet (76 m.) above the Middle Cambrian; (54x) limestone about 200
feet (61 m.) above the Middle Cambrian; and (54u) limestone about 100 feet (30.5 m.) above the Middle Cambrian;
all in the St. Charles formation [Walcott, 1908a, p. 6], on the north side of Twomile Canyon, near its mouth, 2 miles
(3.2 km.) southeast of Malade, Oneida County, Idaho.

(56g) Limestones of the St. Charles formation [Walcott, 1908a, p. 6], in the valley of the stream which flows into
Mill Canyon from the west, about 6 miles (9.6 km.) west-southwest of Liberty, and 15 miles (24.2 km.) west of
Montpelier, Bear Lake County, Idaho.

(54e) About 200 feet (61 m.) above the Middle Cambrian and 1,025 feet (312.4 m.) below the top of the Upper
Cambrian, in limestones forming 3 of the St. Charles formation [Walcott, 1908f, p. 193]; (31m and 55h) about 175 feet
(53.3 m.) above the Middle Cambrian and 1,050 feet (320 m.) below the top of the Upper Cambrian, near the base of
the limestones forming 3 of the St. Charles formation [ Walcott, 1908f, p. 192]; and (54f) 150 feet (45.7 m.) above the
Middle Cambrian and 1,075 feet (327.7 m.) below the top of the Upper Cambrian in the light-gray sandstone forming
4 of the St. Charles formation [Walcott, 1908f, p. 193]; all in Blacksmith Fork Canyon, about 10 miles (16.1 km.) east
of Hyrum, Cache County, Utah. :

(14b) Limestone on Cold Creek at north end of gorge opposite the north end of Sponge Mountain, 2 miles (3.2
km.) south of the San Saba County line, in Llano County; (14g) limestone 1 mile (1.6 km.) west of Cherokee, San
Saba County.; (68 and 68e) interbedded sandstone and limestone, Packsaddle Mountain, Llano County; (69) lime-
stone near Honey Creek, Burnet County; (70, 70a, and 70e) limestones near Morgans Creek, Burnet County; (358a
[Shwmard, 1860, p.627]) sandstones near the head of Morgans Creek, Burnet County; and (71) limestone in Cold Creek
Canyon, Burnet County; all in Texas.

(369e) Sandstone on Big River, Iron County; (369d) upper portion of the Elvins formation, 2.5 to 3 miles (4 to
4.8 km.) north of Caledonia, Washington County; (111) arenaceous limestone of the Elvins formation, 50 feet (15.2 m.)
above the ‘‘Edgewise beds,”’ St. Francois County; and (11d) arenaceous limestone about 2 miles (3.2 km.) north of
Montana, in sec. 22, T. 35 N., R. 1 E., Iron County; all in Missouri.

““St. Croix sandstone” at the following localities: (78) Quarry near St. Croix River in suburbs of Osceola, Polk
County; (79) bluff near Hudson, St. Croix County; (79a) quarry and ledge 0.5 mile (0.8 km.) southeast of the
county courthouse, Menomonie, Dunn County; (100) near Menomonie, Dunn County; (80a) 4 miles (6.4 km.) north
of Reedsburg, Sauk County; (83’) uppermost horizon near Trempealeau, Trempealeau County; (97a) near Winfield,
Jefferson County; (328¢) at Alma, Buffalo County; and (328d [Whitfield, 1882, p. 171]) at Berlin, Green Lake County;
all in Wisconsin. ;

(83°) Green-sand horizon in the “‘St. Croix sandstone” below the ‘‘fifth trilobite bed” of Owen, at Trempealeau,
Trempealeau County, Wisconsin.

“St. Croix sandstone” at the following localities: (84a) River Junction, Houston County, 20 miles (32.2km.) below
Dresbach; (97b) below the green-sand bed and about 25 feet above St. Croix River, at Franconia, Chisago County;
(86a) near Red Wing, Goodhue County; (97 and S97x) at Reads Landing, foot of Lake Pepin, Wabasha County; (181)
inacut on the Chicago, Milwaukee and St. Paul Railway, 4 miles (6.4 km.) southeast of Lake City, Wabasha County;
(339f) near Minneiska (Miniska), on Mississippi River near the line between Wabasha and Winona counties; (339h
[Hall, 1863, p. 185]) near the mouth of Minneiska (Miniska) River, near the line between Wabasha and Winona
counties; (98a) at Marine Mills, on St. Croix River, Washington County; and (339g) just below the Dicellocephalus
minnesotensis beds, near Winona, Winona County; all in Minnesota.

Upper? Cambrian: (306) Sandy limestone on Gravel River, on the eastern slope of the Rocky Mountains, in the
Mackenzie Basin, British Columbia.

Middle Cambrian: (5k) Limestone in Meagher County on the road to Wolsey, about 1 mile (1.6 km.) south of the
divide at the head of Sawmill Creek, and 8 miles (12.8 km.) south of Neihart, Little Belt Mountains quadrangle
(U. S. Geol. Survey), Cascade County; (302w) limestone at Madison Mountain; and (159) limestones north of West
Gallatin (Gallatin) River, Gallatin County; all in Montana.

(4e) Limestones about 950 feet (289.6 m.) above the unconformable base of the Cambrian in the divide at the
head of Jackson Creek (locally known as Sheep Creek), a creek flowing into Jackson Lake about 0.5 mile (0.8 km.)
south of its northwestern corner, Teton Mountains, Grand Teton quadrangle (U. 8. Geol. Survey), Uinta County,
Wyoming.

(5b and 54s) Dark blue-gray Langston limestone [Walcott, 1908f, p. 198], just above the Cambrian quartzitic
sandstones, north side of Twomile Canyon, near its mouth, 2 miles (3.2 km.) southeast of Malade, Oneida County,
Idaho. ;

(540) About 900 feet (274.3 m.) above the Brigham quartzite and 3,300 feet (1,005.8 m.) below the Upper Cam-
brian, in the limestone forming 1b of the Ute limestone [Walcott, 1908f, p. 196], in Blacksmith Fork Canyon, about
10 miles (16.1 km.) east of Hyrum, Cache County, Utah.

(1le) Thin-bedded limestones south-southwest of Potosi, Washington County, Missouri.

(2s) Limestone in upper part of Paradowides zone, Hastings Cove [Matthew, 1898b, p. 38], on Kennebecasis Bay,
0.5 mile (0.8 km.) northeast of Torryburn on the Intercolonial Railway northeast of St. John, St. John County, New
Brunswick.

62667°—vot 51. pr 1—_12-—_48

754 CAMBRIAN BRACHIOPODA.

BILLINGSELLA DIcE Walcott.

Plate CI, figures 8, 8a-d.

Billingsella dice Watcort, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 234. (Characterized essentially as below as a new
species. )

In general form and surface this shell is related to B. romingert (Barrande). It differs
from the latter in its strong dental plates, which form a rudimentary spondylium. All the
characters known are illustrated.

FoRMATION AND LOCALITY.—Lower Ordovician?: (319f) Drift bowlder of sandstone found near St. Albans, Franklin
County, Vermont. The lithologic character of the matrix in which this species was found points to the arenaceous

limestones of the Phillipsburg formation just north of the boundary between the United States and Canada as the
source of the bowlder.

BILLINGSELLA EXPORRECTA (Linnarsson).
Plate LX XXVIII, figures 1, la-l.

Orthis exporrecta LINNARSSON, 1876, Bihang till K. svensk. Vet.-Akad. Handl., Bd. 3, No. 12, pp. 12-13, Pl. II, figs.
13-19; Pl. III, figs. 20 and 21. (Described and discussed in English as a new species.)

Orthis exporrecta Linnarsson, Kaysr, 1883, China, by Richthofen, vol. 4, p.35. (Discussed in German in the descrip-

tion of ‘‘O. linnarssoni.’’)

Orthis exporrecta Linnarsson, WALLERIUS, 1895, Undersékningar é6fver Zonen med Agnostus lxvigatus 1 Vestergétland,

p. 66. (Localities mentioned in Swedish.)

Billingsella exporrecta (Linnarsson), Watcorr, 1905, Proc. U. 8. Nat. Mus., vol. 28, pp. 234-236. (Described and
discussed: essentially as below.) _ . =

Shell transversely subsemicircular, with the hinge line usually shorter than the greatest
width. In a few examples it is a trifle longer; the cardinal angles are obtusely angular (Pl.
LXXXVIII, fig. le). The proportions between the length and breadth vary, as shown by
the figures. The ventral valve is considerably more convex than the dorsal: The ventral
valve is evenly rounded, while the dorsal usually has a flattening of the median area and some-
times a slight, broad sinus. The surface is marked by numerous radiating coste and very
fine concentric striz between the costz, and a few visible lines of growth. The coste are
rounded, usually, but not always, broader than the interspaces, and continuous from the
umbo to the front and lateral margins; they appear to be quite regular, although varying
much in size, and increasing somewhat irregularly by interpolation of new coste. This usually
occurs near the umbo, but may occur near the middle of the valve. The largest ventral valve
in the collection has a length of 9mm. and a breadth of 11 mm. Dorsal valve: Length, 7 mm.;
breadth, 10 mm.

Cardinal area of ventral valve high and overhanging the posterior margin. Delthyrium
large and triangular in outline; deltidium short, concave, imperforate, and marked by fine,
transverse strive of growth. Cardinal area of dorsal valve short and inclined slightly forward;
it is divided midway by a broad delthyrium, which is divided by a strong cardinal process.

In the interior of the ventral valve stfong main vascular sinuses extend well forward
toward the front margin. The cast of the umbonal cavity opposite the delthyrium shows
a tripartite division, the center of which is the area of the path of advance of the diductor
muscle impressions, and those on each side appear to be the posterior portion of the main
vascular sinuses. The anterior edge of the cavity is marked by a sharp, elevated, forward-
arching ridge that extends to the teeth on either side; the dental plates appear to have
extended to the bottom of the valve and to have bounded the sides of the triangular umbonal
cavity opposite the delthyrium.

The interiors of the dorsal valve are beautifully preserved. The cardinal process, crura,
crural plates, area, anterior and posterior adductor muscle scars, and vascular sinuses are
very distinct; the dental sockets are shallow, but clearly shown. The great variation in the
size, form, and position of the adductor scars is well illustrated by the figures. In figure 1f
there appear to be two lateral supporting septa to the thickening before the crural plates that

ee

BILLINGSELLID. 799

bound the spaces occupied by the poimt of attachment of the diductor muscles. Linnarsson
describes [1876, p. 12] the cardinal process as triangular. I find it both straight (fig. 1f),
subtriangular (fig. 11), and triangular (figs. 1g and 1h). A short median septum is seen in
some shells (fig. 1g), but usually the strong, slightly rounded, flattened median ridge does
not carry it.

Observations.—This is one of the most variable species of the genus, both in external,
and, as far as known, internal characters. It is very abundant, but interiors of the ventral
valve are rarely met with in good condition.

The extremely short, imperforate deltidium of the ventral valve indicates that the pedicle
opening had been closed by shell growth, and that this species was nearing the Hoorthis rem-
nicha stage of development. It appears to be an intermediate form between Billingsella and
Hoorthis. The concave deltidium is much like that of Conchidiwm nysius Hall and Whitfield
[Hall and Clarke, 1894, Pl. LXIV, fig. 7]. It is about one-fifth the length of the delthyrium.

Linnarsson [1876, p. 12] compares ‘‘Orthis exporrecta” with “Orthis hicksi,” which appeared
to be most nearly related, pointing out that it differed in having fewer and coarser ribs, less
pointed beak, and lower area. The “Orthis hicksi” variety is now placed as a variety of
Billingsella exporrecta.

FORMATION AND LOCALITy.—Upper? Cambrian: (310h) Shale collected somewhere (probably Fogelsang) in the
old province of Skane, Sweden.

Middle Cambrian: Limestones of the Paradoxides forchhammeri zone at the following localities: (320m) at
Kinnekulle, northeast of Lidképing, Province of Skaraborg; (320n) af Lovened, Djupadal, 19 miles (30.6 km.)
south-southeast of Skara, Province of Skaraborg; (320y)* at Gudhem, 12.5 miles (20.1 km.) south-southeast of Skara,
Province of Skaraborg; (320p)% at Sodra Méckleby, southern part of Oeland Island; (320z)¢ several places in
Nerike; (320g) at Borgholm, Oeland Island; (321q) at Munkesten, north of Hunneberg; and (321r) at Hunnebere,
western boundary of the Province of Skaraborg; all in Sweden.

(3201) @ Drift blocks supposed to have come from the Paradowxides wlandicus zone [Linnarsson, 1876, p. 6], at
Lillviken, near Oestersund, Province of Jemtland; (321p [Wallerius, 1895, p. 67]) in strata with Agnostus levigatus
at Carlfors, near the north end of Mount Billingen, Province of Wermland; (310z) at Brantevik, on the shore a little
south of Simrishamn, Province of Christianstad; (320b) limestones forming 2d of the Paradowides zone, the Agnostus
levigatus horizon, at Gudhem, 12.5 miles (20.1 km.) south-southeast of Skara, Province of Skaraborg; and (310b) dark-
brown limestone at Borgholm, Oeland Island; all in Sweden.

BILLINGSELLA EXPORRECTA RUGOSICOSTATA Walcott.
Plate LXX XVIII, figures 2, 2a-c.

Orthis hicksi LiINNARSSON [not SaurER MS., Davipson], 1876, Bihang till K. svensk. Vet.-Acad. Handl., Bd. 3, No.

12, pp. 13-14, Pl. ITI, figs. 22 and 23. (Described and discussed in English.)

Billingsella exporrecta rugosicostata Waxcorr, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 236. (Discussed as below as a
new variety.)

Linnarsson [1876, p. 13] recognized that this shell was not the same as his “Orthis exporrecta”’
and placed it provisionally under Orthis hicksi, calling attention to the fact that it was nearly
related to O. exporrecta. With a fine series of specimens for comparison, I place the shell as a
variety of B. exporrecta. It is characterized by its strong, irregular cost. Linnarsson [1876,
p. 14] gives as the most important differences: “Ventral valve less convex; cast of diductor
muscle scars less distinct; dorsal valve more convex and muscle scars more strongly marked;
radiating ribs in the casts fewer, stronger, and more angular.” All of the differences exist
when we compare the extreme forms, but with a good series of specimens most of them pass
gradually into forms that are typical of B. exporrecta.

_ FoRMATION AND LocaLiry.—Middle Cambrian: Limestones of the Paradoxides forchhammeri zone at the following
localities [Linnarsson, 1876, p. 14]: (320m) At Kinnekulle, northeast of Lidképing, Province of Skaraborg; (320n) at
Lovened, Djupadal, 19 miles (30.6 km.) south-southeast of Skara, Province of Skaraborg; and (8320p) at Sédra Méck-
leby, southern part of Oeland Island; all in Sweden.

(320b) Limestone forming 2d of the Paradowides zone, the Agnostus levigatus horizon, at Gudhem, 12.5 miles (20.1 km.)
south-southeast of Skara, Province of Skaraborg, Sweden.

a Linnarsson, 1876, p. 13.

756 CAMBRIAN BRACHIOPODA.

BILLINGSELLA HICKSI (Salter MS.) (@avidson)t

Plate XCVII, figures 7, 7a—b.

Orthis hicksii (SauTER MS.) Dayrpson, 1868, Geol. Mag., vol. 5, p.314, Pl. XVI, figs.17-19. (Described asa new species;
see below for copy.)

Orthis hicksti Davipson, 1869, British Fossil Brachiopoda, vol. 3, pt. 7, No. 3, p. 230, Pl. XX XIII, figs. 13-16. (De-
scribed. Figs. 13a and 14a are copied from Davidson, 1868, Pl. XVI, figs. 17a and 18a. Fig. 16a is an enlarged
drawing of the specimen figured by Davidson, 1868, Pl. XVI, fig. 19. Jigs. 14a, 13a, and 16a are copied in this
monograph, Pl. XOVII, figs. 7, 7a—b, respectively.)

Orthis hicksi Davidson, Kayser, 1883, China, by Richthofen, vol. 4, p. 35. (Discussed in German in the description
of ‘‘O. linnarssoni.”’

Billingsella hicksi (Davidson), Waucotr, 1905, Proc. U. 8. Nat. Mus., vol. 28, p. 237. (Original description, Davidson,
1868, p. 314, copied as below.)

The original description by Davidson follows:

Shell small, transversely oval; hinge line shorter than the greatest breadth of the shell; cardinal angles rounded.
Dorsal valve semicircular, moderately convex, slightly longitudinally depressed along the middle. Ventral valve
convex, deeper than the opposite one. Area triangular, moderately wide; surface of valves ornamented by about
ten principal narrow, radiating ribs, with wide interspaces between each pair, in the middle of which is situated a
shorter rib. ‘

Length about 4, width 5, nent

This shell is most nearly related to B. exporrecta. It differs in its more rounded form, fewer
radiating ribs, and muscle area of ventral valve.
The specific name was given in honor of Henry Hicks.

FORMATION AND LOCALITY.t—Middle Cambrian: Sandstones in the middle portion of the Menevian at the following
localities [Davidson, 1869, p. 230]: (818d) at Porth-y-rhaw; (318h) at St. Davids; and (8318p) at Ninewells; all near
St. Davids, South Wales.

BILLINGSELLA HIGHLANDENSIS (Walcott).

Plate LXX XVII, figures 4, 4a-c. -

Orthis? highlandensis Waucortr, 1886, Bull. U.S. Geol. Survey No. 30, pp. 119-120, Pl. VIII, figs. 3, 3a-b. (Described
and discussed as a new species. The specimens represented by figs. 3, 3a—b are redrawn in this monograph,

Pl. LXXXVII, figs. 4c, 4b, and 4, respectively.)

Orthis ? highlandensis Waxcort, 1891, Tenth Ann. Rept. U. 8S. Geol. Survey, p. 612, Pl. LX-XII, figs.5,5a-b. (Men-
tioned. The figures are copied from those in the preceding reference. )

Billingsella highlandensis Waxcort, 1905, Proc. U. S. Nat. Mus., vol. 28, pp. 237-238. (Described and discussed
essentially as below.)

Shell transversely oval or subrotund. Front broadly rounded and nearly straight in the
dorsal valve. On the ventral valve the cardinal line slopes toward the beak at an angle of
about 20°, while in the dorsal valve it is less than 10°. The greatest width is about the middle
of the shell. The ventral valve is moderately convex, being most elevated toward the beak,
which is slightly arched over to the cardinal margin.

A dorsal valve associated in the same hand specimen of limestone is more conyex than the
ventral valve. The cardinal line is shorter than the greatest width of the shell. The median
fold is but slightly raised above the general surface, although the front margin has a low, broad
arch for the reception of the fold of the ventral valve. ;

A slight flattening im the central portion of the ventral valve in some specimens forms a
low, ibmon mesial sinus toward the front margin.

The surface is marked by concentric lines of erowth and fine radiating ribs; on some >
specimens stronger ribs occur very much as on Billin gsella coloradoensis (Pl. LXXXYV, figs.

lai). Interior casts of the valves show fine, radiating strizs toward the front. In a manana a
of partly exfoliated shells, the shell is shown to be thick and apparently solid, having been
replaced by calcite.

The average-sized ventral valve has a length of 13 mm., with a width of 16 mm. One
dorsal valve is 17 mm. in width.

a Specimens from localities 318h and 318p are included in the collections of the United States National Museum. The type locality is either
818d or 318p, Davidson does not indicate which.

BILLINGSELLID. ToT

Cardinal area of the ventral valve unknown except that its plane extends backward at an
angle of about 10° or 15° to the plane of the margin of the shell.

Casts of the interior of the ventral valve show that the dental plates extend down to the
bottom of the valve, supporting distinctly defined hinge teeth. The traces of a vascular system
are limited to the main vascular trunks, which extend forward well toward the front margin,
very much as in B. coloradoensis. In one cast (Pl. LX X XVII, fig. 4b) there is a strong furrow
extending from a median furrow obliquely outward to each main vascular sinus. The median
furrow extends backward to the apex of the cast that filled the space beneath the umbo and the
deltidium. This portion of the cast is also marked by fine vertical venation. In another cast
there is a very narrow median furrow. These median furrows probably indicate the beginning
of a septum that in later forms connected the deltidium with the shell. Nothing is known of

-the interior of the dorsal valve.

Observations —Billingsella highlandensis is strongly characterized by its nearly smooth sur-
face, in having the dorsal valve more convex than the ventral, and in the presence in the ventral
valve of a sharp ridge beneath the umbo, indicating the beginning of the growth of a median
septum.

The specific name is derived from the Highland Range, Nevada.

FORMATION AND LocALIry.—Lower Cambrian: (30) Limestone 8 miles (12.8 km.) north of Bennetts Spring, on
the west slope of the Highland Range; and (81a) limestones and interbedded siliceous shales in the Pioche formation [ Wal-
cott, 1908a, p. 11], just above the quartzite on the east side of the anticline, near Pioche; both in Lincoln County, Nevada.

This species is somewhat doubtfully identified from the following locality:

Lower Cambrian: (178a) Sandstone at the south end of Deep Spring Valley, Inyo County, California.

,

BILLINGSELLA LINDSTROMI-(Linnarsson).

Plate LXX XVII, figures 6, 6a-f.
Orthis lindstrémi Linnarsson, 1876, Bihang till K. svensk. Vet.-Akad. Handl., Bd. 3, No. 12, pp. 10-12, Pl. I, figs.
1-8; Pl. II, figs. 9-12. (Described and discussed in English as a new species.)
Biltingsella lindstromt Watcorr, 1905, Proc. U. 8. Nat. Mus., vol. 28, pp. 238-239. (Characterized and discussed
as below.)

The general description of Billingsella coloradoensis applies to this species. The casts of
the interior have the same general flatness of appearance, and the exterior surfaces are not
unlike. In details, the two differ materially. The radiating coste of B. lindstrémi are usually
stronger; the umbo of the ventral valve is more prominent and the beak more incurved. The
interior of the ventral valve shows shorter main vascular sinuses and more limited ovarian areas.

Linnarsson [1876, PI. I] gives a fine series of illustrations of the interior of the ventral valve,
which show that there is considerable variation in the position of the vascular markings. He
states that the small cardinal process appears to be bifid. I find it single in a natural cast in the
limestone from Alunbruk. There is also a narrow median septum, as in the dorsal valve of
B. coloradoensis.

Linnarsson [1876, p. 11] writes:

I do not know any species with which this can be ‘confounded. At least, the adult specimens are always easily
recognized. In the young ones the characters are less marked, especially in the dorsal valves. The interior and
the internal cast of the ventral valve is in all stages of growth easily recognized.

The specific name was given in honor of Dr. G. Lindstrém.

FoRMATION AND LOCALITY.—Middle Cambrian: Limestones of the Paradoxides forchhammert zone at the following
localities: (320m)¢ At Kinnekulle, northeast of Lidképing, Province of Skaraborg; (320n)% at Lovened, Djupadal, 19
miles (30.6 km.) south-southeast of Skara, Province of Skaraborg; (320y)@ at Gudhem, 12.5 miles (20.1 km.) south-
southeast of Skara, Province of Skaraborg; and (3820p) at Sédra Méckleby, southern part of Oeland Island; all [Lin-
narsson, 1876, p. 12] in Sweden. ;

(3201) [Linnarsson, 1876, p. 12]) Drift blocks supposed to have come from the Paradomides elandicus zone, at Lill-
viken, near Oestersund, Province of Jemtland; (320q) 4 limestone at Alunbruk (alum works), southern part of Oeland
Island; (321t) sandstone at Sularp, near Lund, Province of Malméhus; and (821u) at Bjorkelunda, south of Simri-
shamn, Province of Christianstad; all in Sweden. '

a These localities are represented in the collections of the United States National Museum.

758 CAMBRIAN BRACHIOPODA.

BILLINGSELLA MAJOR Walcott.
Plate LXX XVI, figures 1, la.

Billingsella major Watcorr, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 239. (Characterized as below as a new species. )
Billingsella major Waucorr, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, p. 101, Pl. X, figs. land Ja. (Characterized
as in the preceding and as below asa new species. Figs. 1 and Ja are copied in this monograph, Pl. LXX XVI,
figs. 1 and 1a, respectively.) : Fi 3
In general form and convexity this shell is related to Billingsella coloradoensis. It differs
from it in being larger and in having coarser radiating ribs. It is the Upper Cambrian repre-
sentative of the latter species.
FoRMATION AND LOCALITY.—Upper Cambrian: (116) ‘‘St. Croix sandstone” in excavation on Well’s farm, 2 miles
(3.2 kin.) west of Baraboo, Baraboo quadrangle (U. 8. Geol. Survey), Sauk County, Wisconsin.
Specimens that are somewhat doubtfully referred to this species occur at the following i
locality:
Upper Cambrian: (869c) Dolomite above the ‘‘Edgewise beds,’’ in a railroad cut, 0.5 mile (0.8 km.) southwest of
Elvins, 6 miles (9.6 km.) south of Bonneterre, St. Francois County, Missouri. :

BILLINGSELLA MARION Walcott.

Text figures 67A-B.
Billingsella marion Waxcorr, 1908, Smithsonian Mise. Coll., vol. 53, No. 3, p. 102, Pl. X, fig. 5. (Described and dis-
cussed as below as a new species. Fig. 5 is copied in this monograph as fig. 67A.) 5
Dorsal valve transverse; beak small, marginal; sides broadly rounded and merging into
the broadly round, almost transverse frontal margin; cardinal line a little shorter than the
greatest width of the valve and sloping very slightly
from the beak to outer extremities; on one speci-
men the cardinal angle is extended slightly; greatest
width about midway of the length; mesial furrow
narrow at the beak and gradually widening to a
broad, deep furrow, which divides the valve into
two lobes.
FIGure 67.—Billingsella marion Walcott. A, Dorsal valve, the c u 6
type specimen, showing extension of the cardinal angle and Surface smooth, with the exception of a few
a yery broad mesial furrow: B, Dorsal valve withobseure (six or seven) obscure radiating ribs on each lobe.
radiating ribs. A ie 3 10 7 = Ith I 2 l ai} f 6
The specimens represented are from Locality 581, Middle ~ specumen 4 mm. a 1¢ uals 2 eng 1 0 mn.
Cambrian on Mount Stephen, British Columbia (U.S. Nat. Observations.—This species 1s represented by
Mus. Cat. Nos. 53676a and 53676b, respectively). Figure 67A is . =
copied from Wateott[1908d, Pl. X, fig. 5) three specimens of the dorsal valve. They all in-
dicate a thick shell ‘of the Bullingsella salemensis
(Walcott) type (Pl. LXX XVII, figs. 3 and 3a).
The specific name was given for Mrs. L. D. Burling, who collected the type specimen.
FoRMATION AND LOCALITY.—Middle Cambrian: (581) About 1,830 feet (557.8 m.) above the Lower Cambrian in
limestones forming 3b of the Stephen formation [Walcott, 1908c, p. 238 (7)], on the east side of Mount Stephen, about
3,000 feet (914.4 m.) above the Canadian Pacific Railway track, 3.5 miles (5.6 km.) east of Field, British Columbia,
Canada. ‘

BILLINGSELLA OBSCURA Walcott.

Plate LX XXVI, figure 6.
Billingsella obscura Watcorr, 1905, Proc. U. 8. Nat. Mus., vol. 28, p. 239. (Characterized as below as a new species.)

This species is founded on a single dorsal valve that occurs in the form of a cast im sand-
stone. It is transverse, width 18 mm., length 13 mm.; moderately convex, with a slightly
defined mesial flattening that broadens out nearly to three-fifths the width of the shell at the
front margin. The surface of the cast is marked by a few faintly defined, rather broad coste.

The shell is much like the large dorsal valves of Billingsella coloradoensis. It differs in its
broader frontal margin and median flattening.

Formation AND LocALITY.—Middle Cambrian: (74) Sandstone about 300 feet (91.4 m.) above the base of the
Tonto group at the head of Nunkoweap Valley, Grand Canyon of the Colorado, Arizona.

=]
Or
ide)

BILLINGSELLIDA.

BILLINGSELLA ORIENTALIS (Whitfield).
f Plate LX X XVI, figures 2, 2a-b.

Orthisina orientalis WHITFIELD, 1884, Bull. Am. Mus. Nat. Hist., vol. 1, p. 144, Pl. XIV, fig. 6. (Described and
discussed as a new species. Fig. 6 is copied in this monograph, Pl. LXXXYVI, fig. 2.)

Orthisina orientalis Whitfield, Waxcorr, 1886, Bull. U. 8. Geol. Survey No. 30, p. 120, Pl. VII, fig. 6. (Original
description, Whitfield, 1884, p. 144, copied and species discussed. Fig. 6 is copied from fig. 6 of the preceding
reference. )

Orthisina orientalis Whitfield, Watcort, 1891, Tenth Ann. Rept. U.S. Geol. Survey, p. 618, Pl. LX XII, fig. 8. (Men-
tioned. Fig. 8 is copied from Whitfield, 1884, Pl. XIV, fig. 6.)

Billingsella orientalis (Whitfield), Hart and CrarxKe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, p. 230.
(Merely changes generic reference.)

Billingsella orientalis (Whitfield), Watcorr, 1905, Proc. U. 8S. Nat. Mus., vol. 28, pp. 239-240. (Described and dis-
cussed as below.) ‘

The original description by Whitfield follows:

Shell quadrangular in outline, somewhat higher than wide, with vertical and subparallel lateral margins, and
broadly rounded base. Cardinal line rapidly sloping from the apex to the extremities, which are slightly rounded.
Hinge line straight, as long as the greatest width of the shell. Cardinal area broad and high, divided in the middle
by a triangular foramen, which is about as high as wide. Surface of the ventral valve moderately convex, marked
by very fine radiating strize and also by several concentric lines of growth. Filling of the rostral cavity and foramen
large and prominent. Specimen, a cast in shale, of the ventral valve only.

Observations.—The type specimen as described above is flattened in the shale, and also
appears to be compressed laterally. Uncompressed specimens referred to this species, from
the siliceous limestones east of Swanton show the ventral valve to have been rather strongly
convex, and the dorsal valve moderately so. The outer surface as shown in the cast indicates
that it was somewhat like that of Bullingsella coloradoensis, but that it differs in having finer
‘and more numerous threadlike coste. A few traces of concentric striz and lines of growth
are preserved. The material is very unsatisfactory, but it is sufficient to indicate that the
genus occurs in association with Olenellus thompsom in the upper beds of the Lower Cambrian
section.

: FoRMATION AND LOCALITY.—Lower Cambrian: (25a) Limestone on the Hall (Donaldson’s) farm, 2 miles (3.2 km.)
east of Swanton; (26) sandstore northeast of the Corman farm buildings, east of Highgate Springs; (319m) shales of
No. 6 of the section at Parker’s quarry [Walcott, 1891b, p. 278], near Georgia; and (819g [Whitfield, 1884, p. 144]) shales

at Parker’s quarry, near Georgia; all in Franklin County, Vermont. :

BILLINGSELLA PLICATELLA Walcott.

Text figure 1, page 299; Plate LX X XVI, figures 3, 3a—n.

Billingsella plicatella Waucotr, 1905, Proc. U. 8. Nat. Mus., vol. 28, pp. 240-241. (Described and discussed as below
as a new species.)

Shell irregularly subquadrate in outlme. In the ventral valve the cardinal line slopes
toward the beak at an angle of from 5° to 10°, whereas in the dorsal valve it is usually about
1° to 3°. The greatest width of the shell is about the middle. There is some variation in
the relative proportions of length and breadth. Usually, however, the ventral valve is fully
as long as wide, while in the dorsal valve it is slightly transverse. The ventral valve is rather
strongly convex, the dorsal valve being less so. A low, broad mesial sinus occurs on nearly
all specimens of the dorsal valve, and sometimes a distinct smus on the ventral valve.

The surface is marked by cost that give it a plicated appearance m many specimens;
also, concentric lines of growth and very fine, slightly undulating striz. On some shells the
costz and surface markings have been almost entirely removed by abrasion while in others
they are clear and distinct. There is a considerable range of variation in the strength and form
of the surface markings. These are illustrated by the figures on Plate LX X XVI.

When the’shell is exfoliated, fine radiating lnes occur toward the front margins. The
average size of the shell gives a width of about 8 mm., and in the ventral valve a nearly equal
leneth. One specimen has a width of 11 mm.

760 CAMBRIAN BRACHIOPODA.

Cardinal area well defined. It is marked by transverse strie of growth parallel to the
base. The plane of the area extends backward over the cardinal line at an angle of 10° to the
plane of the margin of the shell. The delthyrium is well defined and covered by a convex
deltidium, the extent of which, however, is unknown. The cardinal area of the dorsal valve
is short. No details of the structure have been observed.

The cast of the interior of the ventral valve indicates short hinge teeth supported by, dental
plates. The markings left on the shell by the vascular system, as shown in casts, are two
main vascular trunks which extend nearly in a straight line from the side of the cast of the
deltidial cavity obliquely outward to the anterior fourth of the valve, where they bifurcate.
The inner branch extends in toward the median line, while the lateral branches extend out-
ward, appearing to unite with the peripheral canal. The latter arches about the space that
was probably occupied by the ovarian areas, between itself and the main vascular trunks.
The spaces for the attachment of the muscles between the main vascular trunks appear to
have been large. No subdivision indicating the points of attachment of the different muscles
has been detected. At the posterior portion of the central area there was a narrow, elevated
space that posteriorly passes into the deltidial cavity. The pedicle muscles were probably
attached to the front part of this elevated space. Short, radiating strie near the margin
indicate the presence of minute vascular canals.

In the interior of the dorsal valve the interior of the deltidial cavity supports a small,
well-developed cardinal process or callosity. The crura are short and small, with rounded
dental sockets beside them. Nothing is definitely shown of the vascular trunks or mesial
impressions in the dorsal valve.

Observations.—In form this species is not unlike the convex forms that have been referred
to Billingsella coloradoensis (Shumard) from Trempealeau, Wisconsin. It differs from the
latter in having strongly marked surface plications and a narrower deltidium. From B. striata
it differs in surface characters; also in having a more convex dorsal valve.

FoRMATION AND LOCALITY.—Upper Cambrian: (150a, 153, and 154) Limestones on Dry Creek, just above the
mouth of Pass Creek, about 5 miles (8 km.) north of Hillsdale; (151a) limestone in point overlooking Churn Canyon
on the west side of the Bridger Range; (157 and 158) @limestone north of East Gallatin River, near Hillsdale; and (156b)
limestone north of East Gallatin River, at the north end of the Gallatin Valley; allin the Threeforks quadrangle (U.S. .
Geol. Survey), Gallatin County, Montana. .

, (152) Limestone on ridge between Churn and Cottonwood canyons; and (151) limestone in point overlooking
Churn Canyon; both on the west side of the Bridger Range, Gallatin County, Montana.

Middle Cambrian: (9h) Limestone on Beaver Creek, 5 miles (8 km.) north of York, about 8 miles (12.8 km.)
north of Canon Ferry, Big Belt Mountains, Fort Logan quadrangle (U. 8. Geol. Survey), Meagher County, Montana.

(4j) Limestone at the head of Deep Creek, Canyon quadrangle (U.S. Geol. Survey), Yellowstone National Park,
Wyoming.

BILLINGSELLA PUMPELLYI Walcott.

Plate XCVII, figures 8, 8a-c.

Billingsella pumpellyt Waucorr, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 242. (Described and discussed as below
as a new species. ) ‘ :

General outline subsemicircular, greatest width at the hinge line or a little in advance
of it; considerable variation exists in the relative proportions of length and width; a ventral
valve 8 mm. long has a width of 9 mm.; the dorsal valve is more transverse, length 5.5 mm.,
width 8 mm. The ventral valve is strongly convex, with the umbo arching over to the apex,
which is a little above the plane of the margins of the valve; a very slight median fold occurs
near the front margin; dorsal valve slightly convex and with a shallow median sinus.

The surface is marked by low, sharp ribs with wide interspaces on which fine radiating
striz occur. Concentric lines and strie of growth cross the radiating striz and ribs.

The characters of the cardinal areas of the valves are almost unknown; that of the ventral
valve appears to have been of moderate height and inclined but a little from the plane of the
valve; one interior of the dorsal valve shows a low cardinal process. The cast of the interior

158 is the type locality.

BILLINGSELLID. 761

of the ventral valve shows the presence of a tripartite, elevated umbonal space into which
the strong main vascular sinuses extend, as in Bullingsella coloradoensis. (Shumard); the
sinuses extend forward nearly to the front margin of the valve. Of the interior of the dorsal
valve only the presence of a strong median ridge is known.

Observations.—This species is one of the costate species of the type of Billingsella colorado-
ensis (Shumard) and B. romingeri (Barrande). It differs from them in surface characters.
It may be considered the trans-Pacific representative of B. coloradoensis.

The specific name was given in honor of Raphael Pumpelly.

ForRMATION AND LOCALITY.—Upper Cambrian: (C36) Upper part of the Chaumitien limestone [Blackwelder,
1907a, p. 36 (part of 3d list of fossils), and fig. 9 (bed 2), p. 35], at Chaumitien, Changhia district; and (C61) a dense
black limestone in the uppermost limestone member of the Kiulung growp (Blackwelder, 1907a, pp. 37 and 41 (8d list of
fossils)and fig. 10 (bed 13), p. 38], 3 miles (4.8 km.) southwest of Yenchuang; both in Shantung, China.

BILLINGSELLA RETROFLEXA (Matthew).
Plate XC, figures 1, lah.

Not Gonambonites plana retroflera DE VERNEUIL [PANDER, 1830, Beitrige zur Geognosie des russischen Reiches, p. 77,
Pl. XXYV, figs. 1 and 2].

Clitambonites (Gonambonites) plana retrofleca MATTHEW, 1895, Trans. Roy. Soc. Canada for 1895, 2d ser., vol. 1, sec. 4,
No. 13, p. 267, Pl. II, figs. la-e. (Original description of Gonambonites plana retroflexa by de Verneuil [Pander,
1830, p. 77] copied and variety from Cape Breton described and discussed. The specimens represented by
ficures la and 1b are redrawn in this monograph, Pl, XC, figs. 1g and 1f, respectively.)

Clitambonites planus retroflecus (Matthew), ScaucuERT, 1897, Bull. U.S. Geol. Survey No. 87, p. 184. (Merely changes
generic reference. )

Billingsella retrofleca MattHEw, 1903, Geol..-Survey Canada, Rept. Cambrian Rocks Cape Breton, pp. 148-151, Pl.
X, figs. 2a-e. (Described and discussed. Figs. 2a, 2c, and 2e are copied from Matthew, 1895b, Pl. II, figs.
la-c, respectively. The specimens represented by figs. 2a, 2c, and 2d are redrawn in this monograph, Pl. LX,
figs. Ig, 1f, and 1c, respectively. )

Orthis (Plectorthis) retrofleca (Matthew), Wancorr, 1905, Proc. U. 8S. Nat. Mus., vol. 28, pp. 270-271. (Characterized
and discussed essentially as below.)

This species is distinguished by the fine radiating costz on the ventral valve (PI. XO,
figs. 1, 1a-c) and coarser costz on the dorsal (fig. 1f). The fine longitudinal striz on the
costz are shown by figure te. The latter are similar to those of Hoorthis remnicha (Pl. XCII
fig. 2c). All that could be definitely determined of the interior of the valves in the type
material sent me by Matthew is shown by figures 1f, 1g, and 1h. In figure 1g of the ventral
valve the casts of the pseudospondylium, area, one base of the main Toso sinuses are
shown. In figure 1f of the dorsal valve the casts of the strong cardinal process, dental sockets,
and crura are shown, and in figure 1h the ovarian areas and the visceral area between them.
Matthew [1903, p. 148] describes other features of the interior of the valves.

The character of the coste and general features of this shell, as far as known, appear to
class it with Billingsella romingeri (Barrande) (Pl. XC) and B. coloradoensis (Shumard) (PI.
LXXXyYV).

Matthew’s very full description [Matthew, 1903, pp. 148-151] should be read by the
student of this species. By imadvertence [Walcott, 1905a, p. 270] I referred it to Orthis (Plec-
torthis), a name which I was then using to include those forms which are now placed under
Eoorthis.

ForRMATION AND LOCALITY.—Middle Cambrian: (307d [Matthew, 1903, p. 149]) Sandy limestone of Matthew’s
[1908, p. 19] Etcheminian, on Young (McFees) Point, near George River, Cape Breton, Nova Scotia.

BILLINGSELLA RICHTHOFENI Walcott.

Plate LX XXIX, figure 1.
Billingsella richthofent Watcorr, 1905, Proc. U. 8S. Nat. Mus., vol. 28, pp. 242— 3243. (Characterized and discussed as
below as a new species. )
This species is represented by two specimens of the exterior of the ventral valve measuring
4 and 5 mm., respectively, in length and width, these bemg about the same. The outer sur-
face is aasulzadl by fine, obscure, sagan ribs and very ne concentric striz. The general

762 CAMBRIAN BRACHIOPODA.

form is much like that of the ventral valve of Billingsella pumpellyr. It differs from the
latter in having. a shorter hinge line in proportion to the width, in the more uniform and
stronger convexity of the surface, and in the more elevated apex.

The species is named after Dr. Ferdinand von Richthofen.

ForMATION AND LOCALITY.—Lower Cambrian: (€3) Lower part of the Manto shale [Blackwelder, 1907a, p. 28
(list of fossils at bottom of page), and fig. 8a (bed 20), p. 28] 2.5 miles (4 km.) southwest of Yenchuang, Sintai district,
Shantung, China.

A single specimen of a fragmentary ventral valve that may belong to this species occurs
in the following locality:

Lower Cambrian: (€20) Central part of the Manto shale [Blackwelder, 1907a, p. 26 (last list of fossils), and
fig. 6 (bed 14), p. 25] on the west side of an isolated butte 1 mile (1.6 km.) south of Changhia, Shantung, China.

BILLINGSELLA ROMINGERI (Barrande).

Plate XC, figures 2, 2a-n.

Orthis romingeri BARRANDE, 1848, Naturw. Abhandl., von Haidinger, Bd. 2, Abth. 1, No. 5, p. 203, Pl. XVIII, figs.
5a-d. (Described and discussed in German as a new species.)
Orthis romingeri BARRANDE, 1879, Systéme silurien du .centre de la Bohéme, vol. 5, pt. 1, Pl. LXII, figs. m: 1-4.

(Figs. 3a, 3c, 3b, 3d, and 3e are copied in this monograph, Pl. XC, figs. 2, 2a-d, respectively.)

Orthis romingeri Barrande, Pomprcss, 1896, Jahrb. K.-k. geol. Reichsanstalt, Bd. 45, Hit. 3, pp. 513-514, Pl. XV,
figs. 15a. (Described and discussed in German.)

Billingsella romingeri (Barrande), Waxucort, 1905, Proc. U. 8. Nat. Mus., vol. 28, pp. 243-244. (Described and dis-
cussed as below.)

Shell transverse, the general outline being irregularly subquadrate to subsemicircular. On
the ventral valve the cardinal line slopes toward the beak at a low angle, while in the dorsal
valve it is approximately straight. In some shells the greatest width is at the hinge line, while
in others it is about the middle of the valve. There is considerable variation in length and

breadth, as may be seen by comparing the figures illustrating this species.

The ventral valve is rather strongly convex and the dorsal valve moderately so. The
dorsal valve is slightly flattened from the umbo to the frontal margin, the flattening sometimes
taking the form of a shallow depression. A low, broad mesial sinus occurs on the dorsal valve
and is strongly marked in the young shells. The surface is marked by rounded, bifurcating,
radiating coste crossed by concentric lines of growth and undulating concentric striz. The
radiating costs vary in size and character in specimens from the same locality. In some
specimens they are very regular, while in others there will be wider interspaces or a variation
in the manner of interpolation. The ridges of growth also vary in strength and elevation in
different shells. :

The largest shell in a considerable quantity of material has a length in the ventral valve of
13 mm. and in the dorsal valve of 10 mm., with a width of 15 mm. Cardinal area of ventral
valve rather high and slightly incurved. It is marked by transverse striz of growth that cross it
parallel to its base; the plane of the area extends backward at an angle of about 10° to the plane
of the margin of the shell; the delthyrium is rather large; a deltidium is indicated in some of
the casts, but none of the specimens show it clearly. The cardinal area of the dorsal valve is
about one-half the length of that of the ventral valve; it extends backward at an angle of more
than 45° to the plane of the margin of the valve and is divided midway by a strong delthyrium
which is covered, for a part of its distance at least, by a convex chilidium.

The traces of the vascular system in the ventral valves are seen in the main vascular trunks,
which extend well forward toward the front margin, where they appear to bifurcate, the inner
branch extending toward the median line and the lateral branches apparently connecting with
the peripheral canal that arches backward about the ovarian areas between it and the main
vascular trunks. No points of attachment of the various muscles in the ventral valye have
been observed. The area in which the diductor muscles are attached is well marked in Plate
XC, figures 2h and 2i, and the cardinal process of the dorsal valve in figures 2] and 2k. There

aati nite eimai

BILLINGSELLID. 763

_ are also in the dorsal valve the anterior adductor impressions, as shown in figure 2k. In the
interior of the dorsal valve the deltidial cavity separates a small cardinal process or callosity,
which is straight (fig. 21) or subtriangular (fig. 2k). The crura are relatively long and very
prominent, with distinctly defined dental sockets beside them.

Observations.—This species was well illustrated by Barrande [1879a, Pl. LXII, fig. mJ], and
I have copied five of his figures of a specimen showing the two valves united. In the material
of the collections of the Museum of Comparative Zoology, Cambridge, Massachusetts, there is
a fine series, illustrating the interior of the ventral and dorsal valves, that, through the ‘Emi mass
of Dr. Nesaadan Agassiz, I was enabled to study and illustrate.

The species in its eciemnal and internal shape varies so decidedly from all described forms
that it is not necessary to point out differences between them.

The specific name was given in honor of Dr. Carl Rominger.

FoRMATION AND LOcALITY.—Middle Cambrian: (345 [Pompeckj, 1896b, p.509])@ Greenish shale in the Paradoz-

ides zone, on the Dlouh4 Hora, above the brook of Sbiroy, near Skrej; (345c)@ in shales of Htage O at Mleschitz; (345f)
in Etage C[Barrande, 1879a, PL. LX II), near Skrej; (345g) in Etage © [Barrande, 1879a, Pl. LXII], at Praschno Insendl:

(8451) shales of Etage © at Jinec; and (345h) in Etage C [Barrande, 1879a, Pl. LXIT], at Slap; all in Bohemia, Aamnstiien ;
Hungary.

BILLINGSELLA SALEMENSIS (Walcott).

Plate LXX XVII, figures 3, 3a.

Orthis salemensis Watcort, 1887, Am. Jour. Sci., 3d ser., vol. 34, pp. 190-191, Pl. I, figs.17 and 17a. (Described and
discussed as below as a new species. The spactanens represented by fags. 17 onl 17a are redrawn in this mono-
graph, Pl. LX X XVII, figs. 3 and 3a, respectively.)

Orthis salemensis Walcott, OnHLERT, 1889, Annuaire géologique universel for 1888, tome 5, 1889, p. 1139. (Described
in French.) ;

Orthis salemensis Waxcorr, 1891, Tenth Ann. Rept. U.». Geol. Survey, pp. 612-613, Pl. EX XII, figs. 6 and 6a. (The
text and figures are copied from Walcott, 1887, pp. 190-191, Pl. I, figs. 17 and 17a, respectively.)

Billingsella salemensis Watcort, 1905, Proc. U. 8. Nat. Mus., vol. 28, p. 245. (Text copied from Walcott, 1887, pp.
190-191.)

Shell about the average size of the Cambrian species of the genus. Transversely subquad-
rilateral; front broadly rounded and slightly smuate midway; hinge line as long as the greatest
width of the shell.

Ventral valve convex, most elevated about one-fourth the distance from the beak to the
anterior margin; beak small and incurved to the margin of the medium-sized area; the surface
of the area and the foramen have not been observed; mesial sinus broad and shallow, it is
marked by a low median rib and laterally by two costz on each side, a third appearing just
outside the sinus.

The dorsal valve, associated in the same hand specimen of limestone, is slightly more
convex; frontal margin with a rather deep sinuosity to receive the projection of the ventral
valve; median fold broad and but slightly elevated, marked by two or three low cost; the
beak appears in the broken specimen in the collection to be scarcely elevated above the surface
of the shell, and to terminate at the cardial margin; area unknown.

The surface of both valves is marked by fine concentric lines of growth, and low, rounded
costa, varying in number from six or seven, as in the specimens ficured, to twelve to fourteen
in oulngr specimens.

In the broad cost and the general aspect of the shell this species is un ike any known to
me from the Cambrian, with the exception of Billingsella whitfieldi (Walcott), from which,
however, it differs in strength and character of coste and outline of valves.

The specific name is derived from Salem, New York.

FoRMATION AND LOcALITy.—Lower Cambrian: (319b) Conglomeratic limestones at St. Simon; and (319h) lime-
stone bowlders in conglomerate at Metis on the St. Lawrence below Quebec; both in the Province of Quebec, Canada.

a These localities are represented in the collections of the United States National Museum.

764 CAMBRIAN BRACHIOPODA.

(2b) Limestone just north of Beman Park, in the northeastern part of the city of Troy; Troy quadrangle (U. 8.
Geol. Survey), Rensselaer County; (22a) limestone in Penrhyn quarries, Middle Granville, Mettawee quadrangle
(U. 8. Geol. Survey), Washington County; and (367a) limestone about 0.33 mile (0.5 km.) south of John Hulett’s
farmhouse, 3 miles (4.8 km.) west of South Granville and 4.5 miles (7.2 km.) southwest of Granville, Fort Ann quad-
rangle (U. S. Geol: Survey); all in New York.

(838d) Limestone 1 mile (1.6 km.) south of Shushan; (21 and 37) shales and limestone 1.5 miles (2.4 km.) south
of Salem; (36) limestone 1 mile (1.6 km.) south of Shushan and 3.5 mules (5.6 km.) north-northeast of Cambridge; and (33)
limestone on the roadside near Rock Hill schoolhouse, near North Greenwich, about 5 miles (8 km.) northwest of Green-
wich; all in the Cambridge quadrangle (U. S. Geol. Survey), Washington County, New York.

- Specimens that are doubtfully referred to this species occur at the following locality,

the stratigraphic horizon of which is doubtful:

Lower Cambrian: (367b) Sandstone at Lansingburg, north of Troy, Cohoes quadrangle (U. S. Geol. Survey),
Rensselaer County, New York.

BILLINGSELLA STRIATA Walcott.

Ca

Plate LXX XVI, figures 4, 4a-c.

Billungsella striata Waucort, 1905, Proc. U.S. Nat. Mus., vol. 28, p. 245. (Characterized as below as a new species.)

The form of the ventral valve of this species is much like that of Billingsella plicatella:
It differs:in having a finely striated outer surface, and in the strong development of the main
vascular sinuses, and the broader deltidial cavity. The only two specimens of the dorsal
valve are nearly flat.

FORMATION AND LOcALITY.—Middle Cambrian: (149a) Limestone at the forks of Hole Creek, above Cherry Gres
basin, Threeforks Gueschemgls (U.S. Geol. Survey), Madison County, Montana.

BILLINGSELLA WHITFIELDI (Walcott).

Plate LXX XVI, figures 5, 5a.

Kutorgina whitfieldi Waucorr, 1884, Mon. U. S. Geol. Survey, vol. 8, pp. 18-19, Pl. IX, figs. 4, 4a-b. (Described
and discussed essentially as below as a new species. The specimens represented by figs. 4, 4a—b are redrawn
in this monograph, Pl. LX X XVI, figs. 5 and 5a, respectively.)

Billingsella whitfieldi (Walcott), ScHucHERT, 1897, Bull. U. 8. Geol. Survey No. 87, p. 159. (Merely changes generic
reference.)

Billingsella whitfieldi Waxcorr, 1905, Proc. U. S. Nat Mus., vol. 28, p. 246. (Described and discussed as below, an
almost exact copy of the original description, Walcott 1884b, pp. 18-19.)

Shell convex, hinge line straight and a little less than the greatest width of the shell, sides
rounding regularly into the slightly convex frontal margin.

Ventral valve fairly convex, elevated along the center to form a flat depressed fold, and
sloping somewhat rapidly from this to the lateral and cardinal margins; median elevation with
about five rather faintly defined, simple plications, that reach up to the higher portion of the
valve; beak small, a little depressed, and rising above the area; cardinal margins straight and
diverging from the beak at an obtuse angle; character of area unknown. .

Dorsal valve depressed convex, with a rather wide, shallow median depression, and two
short plications on each side of it toward the front, which are obsolete in some of the specimens;
the area between the cardinal edges and the elevation of the sides of the mesial depression is
depressed and corresponds to the flattened lateral slope of the ventral valve.

Surface marked by fine, very clearly defined concentric striz that are crowded together
into narrow ridges, and are subparallel to the front and lateral margins of the shell.

Billingsella whitfield: belongs with the group of species including B. salemensis, or shells
with coarse plications and very fine concentric striz. The latter species occurs with the Olenel-
lus fauna in eastern New York, and B. whitfieldi in the Middle Cambrian of central Nevada.

The specific name was given in honor of R..P. Whitfield.

FORMATION AND LOCALITY.—Middle Cambrian: (55b) Top of the Eldorado limestone [see Walcott, 1908f, p. 184],
west side of Secret Canyon; and (55) shaly limestone at the top of the Eldorado limestone [Walcott, 1908f, p. 184], east

slope of Prospect Mountain, in New York Canyon; both in the Eureka district [Hague, 1892, Atlas], Eureka County,
Nevada.

BILLINGSELLIDZ. 765

Genus ORUSIA Walcott.@

Orthis (Orusia) Waucorr, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 273. (Characterized and discussed essentially as
below as a new subgenus.)
Orusia WALcorTT, 1908, Smithsonian Misc. Coll., vol. 58, No. 4, Pl. XI, and pp. 142 and 148. (Classification of genus.)

Orthis lenticularis of authors is not an Orthis as restricted by Hall and Clarke [1892c,
pp. 192-194]. It appears to belong more nearly to the group of species assembled under
Hoorthis. It departs from Hoorthis in its very thin shell, subequally convex valves, small
umbonal cayity, and wide variation in form and surface characters.

Type —Anomites lenticularis Wahlenberg [1821, p. 66].

OrusiIA? EUREKENSIS (Walcott).

Plate CI, figures 7, 7a.

Orthis eurekensis Waucotr, 1884, Mon. U. S. Geol. Survey, vol. 8, pp. 22-23, Pl. IX, figs. 8 and 8a. (Described as
a new species. The specimens represented by figs. 8 and 8a are redrawn in this monograph, Pl. CI, figs. 7a and
7, respectively. )

Protorthis? ewrekensis (Walcott), Hatt and CrarKe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, p. 282.
(Merely changes generic reference.) 4

Orthis? eurekensis Walcott, ScHucHERT, 1897, Bull. U. 8. Geol. Survey No. 87, p. 286. (Merely accepts the original
generic reference.)

Orthis (Orusia?) eurekensis WALcort, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 277. (Described and discussed as below.

General form rounded subquadrate; strongly convex. Surface marked by fine, rounded,
radiating ribs, five in the distance of 1 mm. Length of ventral valve, 4 mm.; width,
4.5 mm.; dorsal valve a trifle shorter.

Ventral valve with a high median fold over the umbo, that widens and flattens toward
the front margin, which is arched to receive the projecting median depression of the dorsal
valve. The umbo curves over to the apex, which overhangs the hinge line. Area low and
strongly inclined backward. The interior cast shows that there was a thick pseudospondylium,
but no details of it are preserved.

Dorsal valve with a deep, gently curved median sinus or depression that extends from
the umbo to the front margin. In the cast strong anterior adductor muscle scars are shown
on the sides of the median depression, and just back of them, in the sus, what may be the
smaller posterior adductor scars.

Observations—This strongly marked shell suggests some of the more convex shells of
Orusia lenticularis (Wahlenberg); it differs in its fine ribs, deep median sinus in the dorsal valve,
and the sharp fold of the ventral valve; also in the presence of a thickened shelf beneath the
umbo of the ventral valve that suggests a spondylium; this character, however, is sometimes
indicated in O. lenticularis (P1. XCVIII, figs. 1e and le).

The specific name is derived from HKureka district, Nevada.

FORMATION AND LOCALITY.—Middle Cambrian: (55b) Top of the Eldorado limestone [Walcott, 1908f, p. 184]
west side of Secret Canyon, Eureka district [Hague, 1892, Atlas], Hureka County, Nevada.

ORUSIA LENTICULARIS (Wahlenberg).
Plate XCVIII, figures 1, la—p, 2, 2a-k, 3, 3a-b, 6, 6a-c.

Anomites lenticularis WAHLENBERG, 1821, Nova Acta Regis Soc. Sci. Upsaliensis, vol. 8, Petrificata telluris Svecanse,
pp. 66-67. (Described in Latin as a new species; see Matthew, 1892, p. 46, for copy of orfginal, and translation. )

Atrypa? lenticularis (Wablenberg), Datman, 1828, K. Svensk. Vet.-Acad. Handl. for 1827, pp. 132-133. (Described
in Latin; see Matthew, 1892, p. 46, for copy of original, and translation.)

a Prior to the definition of the genus Orusia the species now placed under that genus were referred to the following genera:

Anomites Wahlenberg [1821, p. 66]. Atrypa Kjerulf (1879, Pl. XIIT).

Atrypa? Dalman [1828, p. 132].~ Orthis Salter and Etheridge [1881, p. 544].
Spirifera ? von Buch [1834, p. 48). Orthis Brogger [1882, p. 48].

Atrypa? Hisinger [1837, p. 76]. Orthis Walcott [1884b, p. 22}.

Atrupa Kjerulf [1857, p. 92; 1865, p. 3]. Orthis Roemer [1885, p. 33].

Orthis Salter [1866, p. 339). Orthis Matthew [1892, pp. 46, 48, and 49).
Orthis Davidson [1868, p. 314; 1869, p. 230). Protorthis ? Hall and Clarke [1892ce, p. 232].
Orthis Kayser [1876, p. 9]. Orthis ? Schuchert [1897, p. 286).

Orthis Roemer [1876, Pl. II, figs. 4a-c]. Orthis Matthew [1903, pp. 213, 216, and 217).

766 CAMBRIAN BRACHIOPODA.

Spirifera? lenticularis (Wahlenberg), von Bucu, 1834, Physikal. Abhandl. K. Akad. Wiss. Berlin, p. 48, Pl. I, figs.
13 and 14. (Described in German; see Matthew, 1892, p. 47, for translation.)

Atrypa? lenticularis (Wahlenberg) HistncER, 1837, Lethzea Svecica, p. 76. (Not seen.)

Atrypa lenticularis (Wahlenberg), Kimrunr, 1857, Geologie des stidlichen Norwegens, p. 92. (Locality mentioned in
German.)

Atrypa lenticularis (Wablenberg), Ksnruur, 1865, Veiviser ved Geologiske Excursioner i Christiania Omegn, p. 1,
and figs. 7a-d, p. 3. (Mentioned and locality given in Norwegian.)

Orthis lenticularis (Wahlenberg), Santer, 1866, Mem. Geol. Survey Great Britain, vol. 3, p. 339, Pl. IV, figs. 8-10.
(Described and discussed; see Matthew, 1892, p. 47, for copy.)

Orthis lenticularis (Wahlenberg), Davipson, 1868, Geol. Mag., vol. 5, p. 314, Pl. XVI, figs. 20-22. (Occurrence men-
tioned and new localities given.)

Orthis lenticularis (Wahlenberg), DAvipson, 1869, British Fossil Brachiopoda, vol. 3, pt. 7, No. 3, pp. 230-232, Pl.
XXXIII, figs. 22-28. (Described and discussed, copying Wahlenberg’s original description in Latin, 1821,
-p. 66. Figs. 22, 23 and 24, and 25 are copied from Salter, 1866, Pl. IV, figs. 9a, 9b, and 9c, respectively; figs.
28 and 28a are copied from Davidson, 1868, Pl. XVI, figs. 22 and 22a; and figs. 26, 26a—b are redrawn from the
specimen figured by Davidson, 1868, Pl. XVI, figs. 21 and 21a.)

Orthis lenticularis (Wahlenberg)?, KaysEr, 1876, Beitrage zur Geologie und Paleeontologie der argentinischen Repub-

lik, vol. 2, Paleontologischen Theil, Abth. 1, p. 9, Pl. I, figs. 11 and 12. (Characterized and discussed in
German; see pp. 767-768 for translation. ) :
Orthis sp., KaysER, 1876, idem, p. 9, Pl. I, fig. 13. (Characterized in German; see p. 768 for translation.)

Orthis lenticularis (Wahlenberg), RopmeEr, 1876, Lethzea geognostica, pt. 1, Lethzea paleeozoica, Atlas, Pl. IT, figs. 4a—c.

(No text reference. Fig. 4a is copied from Salter, 1866, Pl. IV, fig. 9a; figs. 4b and 4c are copied from David-
son, 1869, Pl. XX XIII, figs. 26b and 26a, respectively.)

Atrypa lenticularis (Wablenberg), KrERuxr, 1879, Sydlige Norges Geologi, atlas, Pl. XIII. (Gives position in vertical
section. )

Orthis lenticularis (Wahlenberg), SALTER and neat eee 1881, Mem. Geol. Survey Great Britain, vol. 3, 2d ed., pp.
544-545, Pl. IV, figs. 8-10. (Text and figures copied from Salter, 1866, p. 339, Pl. IV, figs. 8-10.)

Orthis lenticularis (Wahlenberg), BROGGER, 1882, Die silurischen Etagen 2 und 3, p. 48. (Specimens from new locali-
ties discussed in German.)

Orthis lenticularis (Wahlenberg), RommeEr, 1885, Paleontologische Abhandlungen von Dames und Kayser, Bd. 2, Hit.
5, pp. 33-34 (280-281), Pl. I (XXIV), figs. 9a-c. (Occurrences of the species discussed in German. Fig. 9a is
copied from Salter, 1866, Pl. IV, fig. 9a; figs. 9b and 9c are copied from Davidson, 1869, Pl. XX XIII, figs. 26b
and 26a, respectively. )

Orthis lenticularis (Wahlenberg), MartHEw, 1892, Trans. Roy. Soc. Canada for 1891, vol. 9, sec. 4, No. 5, pp. 46-48,
Pl. XII, figs. 9a-d. (Gives original and translation of Wahlenberg, 1821, p. 66, translations of Dalman, 1828,
p. 132, and yon Buch, 1834, p. 48, and copy of Salter, 1866, p. 339, and dleseiilnes and discusses species. Speci
‘mens from Matthew’s material are figured in this monograph, Pl. XCVIII, figs. 3, 3a—b, but as far as can be
determined none of these specimens were figured by Matthew, 1892, Pl. XII, figs. 9a—d.)

Orthis lenticularis strophomenoides Marranw, 1892, idem, p. 49, Pl. XII, figs. 12a-b. (Characterized and discussed
as a new variety. The specimens represented by Pl. XCVIII, figs. 1c and 2b, of this monograph, are typical of
this proposed variety, but they are drawn from material in the collections of the United States National Museum,
and are not the type specimens.)

Orthis lenticularis (Wahlenberg), Marrapw, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, pp.
213-216, Pl. XVII, figs. la-d. (Text and figures copied from Matthew, 1892, pp. 46-48, Pl. XII, figs. 9a-d.)

Orthis lenticularis strophomenoides MarrHEw, 1903, idem, p. 217, Pl. XVII, figs. 4a—b. (Characterized. Figs. 4a—b
are copied from Matthew, 1892, Pl. XII, figs. 12a—b, respectively.)

Orthis (Orusia) lenticularis (Wahlenberg), Waxcorr, 1905, Proc. U. 8. Nat. Mus., vol. 28, pp. 273-276. (Described
and discussed essentially as below, giving translation of Kayser’s references, 1876, p. 9.

Matthew [1892, pp. 46-48], in his excellent review of the descriptions of this species, gives

a translation of Wahlenberg’s original description, together with the Latin; also the descrip-

tions of Dalman [1828, p. 132], von Buch [1834, p. 48], and Salter [1866, p. 339].

He calls attention [1892, p. 47] to the fact that if the reader will compare the several descrip-
tions of this species by the authorities named he will be surprised at the diversity they exhibit.
This diversity, Matthew thinks, is due partly to the imperfect descriptions of the earlier writers,
but chiefly to the remarkable variability of the species. Matthew recognizes the species in the
Upper Cambrian, near St. John, New Brunswick, and has also distinguished three varieties.
Through his kindness I had the opportunity of studying the types of the varieties.

Through M. Schmalensee, a collector in the Geological Survey of Sweden, I secured a large
and fine series of this species from thin bands of limestone in the Olenus and alum shales on
Oeland Island and at Hunneberg. I also collected a quantity of the shells in the Upper Cam-
brian of Manuels Brook, Newfoundland’ From this material an attempt has been made to

° ie BILLINGSELLIDA. 167

select a series illustrating the great range of variation in form and surface markings, first, from
Sweden; second, from Newfoundland; and third, from New Brunswick. I was not able to
obtain satisfactory material from Wales, but Davidson’s figures [1869, Pl. XXXII, figs. 22-28]
illustrate fully the peculiarities of the species as it occurs there.

The general form of the shell is fairly well shown by the series of figures on Plate XCVIII;
also the great variation in surface characters. Only one specimen was found in which the two
valves were united (Pl. XCVIII, figs. 6, 6a-c). The convexity of the two valves is subequal,
the ventral being a trifle greater. The cardinal view (Pl. XCVIII, fig. 6c) shows how short the
hinge line of both valves is in a specimen where the cardinal extremities are rounded. The
side view shows the angle of slope of the areas of the two valves.

A very careful search of the casts of the interior was made for the purpose of illustrating
the muscle scars and vascular markings, and in a few instances traces of these have been found.
In one illustration (Pl. XCVIII, fig. le) the area (pseudospondylium) beneath’ the umbo of
the ventral valve is outlined, also the main vascular sinuses; in another (Pl. XCVIII, fig. 1p),
drawn from the cast of a small ventral valve, the area, main vascular sinuses, and the details -
of the umbonal cavity are clearly shown. The backward extension of the cast of the grooves
occupied by the sinuses to the apex of the cavity is very distinct; also the area between them
occupied by the path of advance of the scars of the adductor muscles. Matthew [1892, Pl.
X11] illustrates some traces of the vascular markings and muscle scars, but they are almost too
indefinite to be of value. sah

In a single specimen of the ventral valve from Oeland Island (Pl. XCVIII, fig. 1p) the cast
of the umbonal cavity is nearly as sharp as in some specimens of Hoorthis remnicha. The
cavity is tripartite (Pl. XCVIII, fig. 1c), the central division being occupied by the diductor muscle
scars, and the two lateral divisions are continuous with the ridges representing the casts of the
main vascular sinuses. I have been unable to secure any illustrations to show clearly whether
there is a deltidium present or not. The delthyrium is clearly shown in several specimens.
Casts of the interior of the dorsal valve from Newfoundland (Pl. XCVIII, figs. 2f and 2h) show
the presence of crural plates that extend to the bottom of the valve; also short but very
definite crura and small depressions beside the latter for the reception of the teeth of the ventral
valve. A cast of the ventral valve (Pl. XCVIII, fig. 2d) shows that the dental plates extend
to the bottom of the valve; and specimens from Sweden (Pl. XCVIII, figs. le and le) show
that in certain individual ventral valves the dental plates and a transverse arching ridge sharply
define the umbonal cavity.

The average size of the specimens from Oeland Island is about 5 by 6 mm. One dorsal

valve is 7 by 9mm. Those from Hunneberg average from 5 to 6 mm., with occasional shells
7 by 8mm. In Newfoundland great numbers measure 4 by 5 mm., and some have a length
of 10 mm. and a width of 12mm. Matthew [1892, p. 48] states that the average size of the
shells in the Acadian rocks is about 5 by 6 mm. Brégger [1882, p. 48] mentions an example
from Téien, Christiania, Norway, measuring 10.5 mm. by 12.5 mm.

_ I have not attempted any detailed description of the species, as it is so variable in form
and surface markings. An attempt was made to determine varieties in the material from
Sweden and Newfoundland, but there was such a gradation in all of the characters upon which
such differentiation might rest that it was finally abandoned. Matthew [1892, p. 48] considers
that he has reason for establishing varieties among the New Brunswick forms. Whether these
would be of value if a large amount of material were available for comparison is doubtful.

Kayser [1876, Pl. I, figs. 11 and 12] illustrates a shell that is apparently identical with
Orusia lenticularis, which occurs in the sandstone at Tilcuya, Province of Jujuy, Argentina,
in association with Olenus, Agnostus, etc. He also illustrates [1876, Pl. I, fig. 13] a dorsal valve
of a small Orthis that in many respects looks more like O. lenticularis than figures 11 and 12 of
the same work. I very much doubt if they represent this species; in fact, Kayser questions
his identification by an interrogation mark. He says of the shell [1876, p. 9]:

Another, much smaller, (rthis species occurs in the fine-grained sandstones of Tilcuya, associated with Olenus,
Agnostus, Arionellus, Theca, and Orthis saltensis, which has just been described. The smaller Orthis species is

768 CAMBRIAN BRACHIOPODA. .

transversely oval in outline, with straight hinge edge, corresponding to the greatest breadth of the shell. The ventral
valve is moderately arched, the dorsal somewhat less. The surface of both valves is covered with comparatively
strong ribs, arranged in bundles. On the middle of the ventral valve there is an especially well-marked rib or bundle
ofribs. Corresponding to this on the dorsal valve there is a well-marked sinus, limited on each side by a strong bundle
of ribs.

The form just described agrees in the main so well with the figures given by Salter and Davidson of the small
English form identified with Wahlenberg’s lenticularis that I can hardly doubt its specific identity with the latter.

Of Orthis sp. Kayser remarks [1876, p. 9]:

Before me lies a cast from Tileuya, representing a third Orthis species. It isalmost equal in size to O. saltensis,
but differs from it in outline, which is greatly prolonged transversely, the greatest breadth at the hinge edge, and the
feeble winglike projection of the hinge corners. This last-named characteristic and the much larger dimensions also
distinguish this fossil from O. lenticularis. The surface of the shell has been covered with very strong bundles of ribs.

Matthew [1892, pp. 48-49] has named three varieties of Orusia lenticularis. I find essen-
tially the same forms in the collections from Sweden and Newfoundland. Two of the varieties,
Orusia lenticularis atrypoides and O. lenticularis lyncioides, have been illustrated in this mono-
graph from Matthew’s type specimens. The third variety, Orusia lenticularis strophomenoides,
occurs associated with specimens of Orusia lenticularis in the Swedish material, and does not
appear to be of varietal value. It is illustrated in this monograph by Plate XCVIII, figures
1c and 2b.

FoRMATION AND LOCALITY.—Upper Cambrian: (9f) Limestones of the Olenus zone at Noersnees, west of Chris-
tiania; (3231) with Parabolina spinulosa at Toien, about 1 mile (1.6 km.) northeast of Christiania; (328m) Htage 2b
at Oslo, about 1 mile (1.6 km.) southeast of Christiania; (323n [Brogger, 1882, p. 48]) Wtage 2b at Vestfossen, 10 miles
(16.1 km.) west-southwest of Christiania; (3230) Wtage 2b, in the city of Christiania; (3238p) Wtage 2b at Slemmestad,
about 3 miles (4.8 km.) southwest of Christiania; (3284 [Brégger, 1882, p. 101]) Etage 2b at Kartveit, in the
Christiania region; (323r) 4 Etage 2b at Krekling, in Sandsvir; (323s)¢ Etage 2b at Gjégrefos, in Sandsviar; (&28t)
Etage 2b in Hedemarken, east of Lake Mjésen (Midsen), about 40 miles (64 km.) north-northeast of Christiania; (823u) @

Etage 2b at Oxna (Oksna), valley of Glommen River; and (323v [Davidson, 1869, p. 231]) at Hgeberg (about 1.5

miles (2.4 km.) southeast of Christiana?); ail in Norway.

(310a) Shales of Olenus truncatus zone, Oeland Island; (390n) limestones of Olenus zone at Hunneberg, western
boundary of the Province of Skaraborg; (309m) limestones forming 3c of the Olenus series at Alunbruk (alum works),
southern part of Oeland Island; (3900) arenaceous shales at Andrarum, 20 miles (32 km.) northwest of Simrishamn,
Province of Christianstad; and (8390p [Davidson, 1869, p. 231]) at Kinnekulle, northeast of Lidképing, Province of
Skaraborg; all in Sweden.

Drift bowlders of gray bituminous limestone at the following localities [Roemer, 1885, pp. 33 and 34]: (886e)
Between Vistula and Elbe rivers, in Schleswig-Holstein and Mecklenburg-Schwerin; (386f) near Wismar, Mecklen-
burg-Schwerin; (386g) near Rostock, Mecklenburg-Schwerin; and (386h) near Meseritz, Province of Posen; all in
Germany.

Upper Lingula flags at the following localities: (318s) 6 Ogof-ddu Cliff, Carnarvonshire; (366s) 5 miles (8 km.)
east of Ffestiniog, Merionethshire; (318t)® Penmorfa Church, Tremadoc, Carnarvonshire; (318u) ® Gwerny-y-Barcud;
(318v)® Rhiwfelyn; (318) 6 Penmain Pool, west of Dolgelly, Merionethshire; (318a) © Criccieth, Carnarvonshire; and
(318b [Davidson, 1869, p. 232]), near Portmadoc, Carnarvonshire; all in North Wales.

(3). Shaly limestone 300 feet (91.4 m.) above the Paradoxides zone; and (6v) shaly limestones 325 feet (99.1 m.)
above the Middle Cambrian; both on Manuels Brook, Conception Bay, Newfoundland.

(314i) Shale picked up on beach in Smith Sound, Trinity Bay. Newfoundland.

(10h) Shale on small east branch of Barachois River, 0.75 mile (1.2 km.) north of the crossroad from Boisdale
to Upper Leitches Creek; (18q) shales of the Bretonian division of Matthew’s [1903, p. 45] section on Gillis Brook,
East Bay; (307h) ¢ in Division (3b? (possibly C3c) of Matthew’s section, on McLeod Brook=Barachois River; (307i) ¢
in Division C3b of Matthew’s section on McNeil Brook, east of Mira River; (307j)¢ limestone in Division C3b? (pos-
sibly C3c) on East Bay, east of Bras d’Or Lake; and (8071) ¢ limestone in Division C3b? (possibly C3c) on Gillis Brook;
all in eastern Cape Breton, Nova Scotia.

Limestone lentils in black shales of Division C3a of Matthew’s section at the following localities: (308b [Mat-
thew, 1892, p. 48]) on Germaine Street, St. John; and (808f)¢ on Kine Street, St. John; both in St. John County, New
Brunswick.

(389b [Kayser, 1876, p. 9]) Sandstone at Tileuya, Province of Jujuy, Argentina, South America.

Middle Cambrian: (55b) Top of the Eldorado limestone [Walcott, 1908f, p. 184], west side of Secret Canyon,
Eureka district [Hague, 1892, Atlas], Eureka County, Nevada.

(320f) Limestone at Andrarum, 20 miles (32 km.) northwest of Simrishamn, Province of Christianstad, Sweden.

a Brogger, 1882, p. 4. b Davidson, 1868, p. 314. ¢ Matthew, 1903, p. 216.

BILLINGSELLID2. 769

ORUSIA LENTICULARIS ATRYPOIDES (Matthew).

Plate XCVIII, figure 5.

Orthis lenticularis atrypoides MATTHEW, 1892, Trans. Roy. Soc. Canada for 1891, vol. 9, sec. 4, No.5, p. 48, Pl. XII,
figs. Lla-b. (Characterized as a new variety; see below for copy. The specimen represented by fig. lla is
redrawn in this monograph, Pl. XCVIII, fig. 5.)

Orthis lenticularis atrypoides MatrnEw, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, p. 217, Pl.
XVII, figs. 3a-b. (Characterized. Figs. 3a—b are copied from Matthew, 1892, Pl. XII, figs. 1la-b, respec-
tively.)

Orthis (Orusia) lenticularis atrypoides (Matthew), Waxcorr, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 276. (Original
characterization copied as below.)

The original description by Matthew follows:

This form is comparatively smooth, though the ventral valve is sometimes concentrically wrinkled. This valve
is distinguished by a mediar ~idge and somewhat flattened sides, and the dorsal valve has an unusually deep sinus.
Size of the known examples, 6 by 6 mm., and 5 by 6 mm. for the two valves.

FoRMATION AND LOcCALITY.—Upper Cambrian: (308b [Matthew, 1892, p. 48]) Limestone lentils in black shales
of Division C3a of Matthew’s section, Germaine Street, St. John, St. John County, New Brunswick, Canada.

ORUSIA LENTICULARIS LYNCIOIDES (Matthew).

Plate XCVIII, figure 4.

Orthis lenticularis lyncioides MatrrEw, 1892, Trans. Roy. Soc. Canada for 1891, vol. 9, sec. 4, No. 5, p. 49, Pl. XII,
figs. 10a—c. (Characterized as a new variety; see below for copy. The specimen represented by fig. 10a is
redrawn in this monograph, Pl. XCVIII, fig. 4.)

Orihas lenticularis lyncioides MartuEw, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, p. 216, Pl.
XVII, figs. 2a-c. (Characterized. Figs. 2a-c are copied from Matthew, 1892, Pl. XII, figs. 10a-c, respec-
tively.)

Orthis (Orusia) lenticularis lyncioides (Matthew), Waxucorr, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 277. (Original
characterization copied as below.) me

“The original description by Matthew follows:

Distinguished by its sharp, strong, radiating ribs, large umbo, and high cardinal area. In some of the larger
examples the radiating ribs become subordinate to and are replaced on the newer part of the shell by concentric striz,
reversing the usual position of the ribbed and the smooth parts of the shells of this species. Size of the valves about
6 by 8 mm.

I have illustrated a ventral valve from Matthew’s material that is the most strongly marked.
The ventral valves are similar to those from Newfoundland represented by Plate XCVIII,
figures 2h and 2i.

FORMATION AND LOCALITY.—Upper Cambrian: (308b [Matthew, 1892, p. 49]) Limestone lentiles in black shales
of Division C3a of Matthew’s section, Germaine Street, St. John, St. John County, New Brunswick, Canada.

Genus OTUSIA Walcott.

Billingsella (Otusia) Waxcorr, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 246. (Mentioned as a new subgenus.)
Otusia Waxcorr, 1908, Smithsonian Misc. Coll., vol. 53, No. 4, Pl. XI, and pp. 142 and 148. (Classification of genus.)

This name was proposed [1905a, p. 246] to include “ Orthis sandbergi” of N. H. Winchell,
which was the only species known at the time the genus was named. One new species, Otusia
utahensis, has been added since. The generic and specific characters are included in the descrip-
tion of the species. ;
OTusIA SANDBERGI (N. H. Winchell).

a Plate XCIII, figures 4, 4a-d.

Orthis sandbergi N. H. WincuEtt, 1886, Fourteenth Ann. Rept. Geol. and Nat. Hist. Survey Minnesota, p. 318, Pl. If,
figs. 8and 9. (Described as a new species.)

Orthis (2) sandbergi Winchell, Watcorr, 1899, Mon. U. S. Geol. Survey, vol. 32, pt. 2, pp. 452-453, Pl. LX, figs, 2, 24-d.
(Described and discussed as on'p. 770. Figs. 2, 2a-d are copied in this monograph, Pl. XCIII, figs. 4, 4a-d,
respectively. )

a Prior to the definition of the genus Otusia the type species was described under the genera Orthis N. H. Winchell [1886, p. 318] and Orthis ?
Walcott [1899, p. 452).

62667°—von 51, pr 1—12——49

770 CAMBRIAN BRACHIOPODA. -

Billingsella (Otusia) sandbergi (Winchell), Watcorr, 1905, Proc. U. 8. Nat. Mus., vol. 28, pp. 246-247. (Described
and discussed essentially as in preceding reference, p. 769, and as below.)

Shell small, transverse, subquadrate in outline, exclusive of the acute cardinal extremities.
Valves slightly convex, with a straight hinge line longer than the greatest width of the shell;
cardinal area narrow, but well developed on each valve and divided by a rather large open
delthyrium.

The ventral valve slightly flattened at the cardinal extremities, rising toward the center
with a convex triangular swelling, broadening from the narrow beak to the front; beak small,
rounded, and extending slightly beyond the hinge line. Dorsal valve flattened at the cardinal
extremities, with well-marked rounded ridges rismg between them, and a rather broad, well-
defined median sinus; beak very small, slightly encroaching upon the hinge line.

Surface marked by fine, regular, radiating strie, between which one or more faint interme-
diate striz are sometimes visible; under favorable conditions very fine concentric striz can be
seen, and there are also usually present more or less distinctly marked lines of growth.

Very little is known of-the interior of the ventral valve. Two fragments of the posterior

portion show a broad delthyrium, strong teeth, and a broad umbonal cavity opposite the
delthyrium. In the ventral valve the area is narrow and divided by a broad delthyrium, which
has a strong cardinal process that extends forward nearly three times the length of the area.
Anteriorly, it rests on a broad ridge that extends forward, gradually broadening out and disap-
pearing at the anterior margin of the shell.

In my former description [1899, p. 453] I stated that ‘‘the generic character of this species
has not been fully ascertained, but the material from the Yellowstone National Park and
specimens from the typical locality at Red Wing, Minnesota, lead me to think that this can not
be referred to the genus Billingsella. It appears to be an Orthis of the Plectorthis group of
Hall and Clarke.’ A closer study of this species and the forms referred to Buillingsella led me
[1905a, p. 246] to refer it to Otusia on account of its surface characters, the character of the del-
thyrium in the two valves, and the strong cardinal process and median ridge in the dorsal valve.

A comparison of the specimens of this species from the type locality at Red Wing, Min-
nesota, with those from the Yellowstone National Park shows the two shells to be specifically
identical as far as the comparison of casts in sandstone can be made with well-preserved shells
on the surface of limestone.

The specific name was given in honor of Dr. J. H. Sandberg, of Red Wing, Minnesota, who
first called attention to the type locality of this species.

FORMATION AND LOCALITY.—Upper Cambrian: (86a) “St. Croix sandstone® near Red Wing, Goodhue County, Min-
nesota.

(302f) Upper part of the Gallatin formation, north side of Elk Pass, between Buffalo and Slough creeks, Yellowstone
National Park, Livingston quadrangle (U. S. Geol. Survey), Montana.

OTUSIA UTAHENSIS 0. sp.
Plate LXXXIX, figures 3, 3a-c.

This species is represented by several fragments of the two valves. One of the specimens,
represented by figure 3, indicates the general outline of the ventral valve, and figure 3b that of
the dorsal valve. The surface is marked by concentric lines and small ridges of growth and
numerous fine, rounded, radiating ribs that increase by the division of the ribs as they are
lengthened by the growth of the shell. A shallow median sinus occurs on the dorsal valve,
and a rounded median ridge on the ventral valve.

The largest dorsal valve has a width of 9 mm. at the hinge line, with a length of about 6 mm.

‘The generic reference is made on account of the general resemblance of this form to Otusia
sandbergi (N. H. Winchell). It differs from the latter in outline and in the rounded character
of the ribs.

FORMATION AND LOCALITY.—Middle Cambrian: (31c) About 900 feet (274.3 m.) above the Brigham quartzite and

3,300 feet (1,005.8 m.) below the Upper Cambrian in the limestone forming 1b of the Ute limestone [ Walcott, 1908f,
p. 196], in Blacksmith Fork Canyon, about 10 miles (16.1 km.) east of Hyrum, Cache County; (32e) limestone at the

a

BILLINGSELLID. 771

same horizon as that of No. 3lc, just south of the south fork of Paradise Dry Canyon (locally known as Hast Fork), east
of Paradise, Cache County; and (38r) limestones faulted agavnst the Cambrian quartzites in a canyon about 1 mile (1.6 km.),
east of Cricket Spring, Cricket Range (locally known as the Beaver River Range or the Beaver Mountains), northwest of
Blackrock, Millard Cownty; all in Utah.

Genus WYNNIA Walcott.

Wynnia Waxcorr, 1908, Smithsonian Misc. Coll., vol. 53, No. 4, Pl. XI, and pp. 142 and 148. (Classification of genus.)

The description of the type species includes all that is known of this genus. The material
is poor, but sufficient to indicate that the species belongs to an undefined genus. It differs
from Orthis (restricted) in the presence of the large vascular sinuses of the ventral valve and
pointed apex of the dorsal valve. The latter is of the type of the apex of the valves of Nisusia
festinata (Billings). From Billingsella it differs in the absence of dental plates and deltidium
in the ventral valve.

Type.—Orthis wartht Waagen.

The generic name is given in honor of Mr. Arthur B. Wynne, of the Geological Survey of
India.

_— WyYNNIA WARTHI (Waagen).

Text figures 68A—A’; Plate LX XXIX, figures 4, 4a-f.

Orthis warthti WAAGEN, 1891, Mem. Geol. Survey India, Paleontologia Indica, 13th ser., Salt Range Fossils, vol. 4,
pt. 2, pp. 102-104, Pl. I, figs. 12-15, Pl. II, figs. 1 and 2. (Described and discussed as a new species. The
specimen represented by fig. 12b is redrawn in this monograph, Pl. LXX XIX, fig. 4a. The specimen repre-
sented by fig. 14 is redrawn in the same position on Pl. LX X XTX (fig. 4b) of this monograph and in text fig. 68A’.
Different views of the same specimen are shown in this monograph, Pl. LX X XIX, fig. 4, and text fig. 68A, both
of which drawings are of the same shell in the same position. The
text figures are the correct representations in each case. PI. II,
figs. 2a, 2b, and 2c, are copied in this monograph, Pl. LXXXIX_
figs. 4e, 4d, and 4f, respectively.)

Shell small, biconvex, subcircular to broad oval in
outline. Exterior surface unknown. Cast of interior of
ventral valve strongly convex. Apex slightly incurved
-over a rather high area that slopes forward at an angle of
about 45° to the hinge line. The area is formed of two

FIGURE 68.— Wynnia warthi (Waagen). <A, Cast of

narrow sides separated by a large triangular delthyrium interior of a ventral valve (X 4). The shell was

compressed laterally and hence the muscle scars
without traces of a deltidium; ie narrow, elongate sides Be Reena carmen Rome Ra Weseng
are slightly concave and have in the cast a narrow raised A’, Posterior view of same specimen, showing

broken-off beak.
margin next to the delthyrium. The dorsal valve is less RES
The specimen from which figures 68A and 68A/

convex than the ventral, its area slopes forward from the © are drawn is incorrectly figured on Plate LXXXIX,
hinge and at the apex of the valve bends slightly forward, fsutes 4 and 4b, of this monograph, and is the speci-
ica 5 men figured by Waagen [1891, Pl. II, fig. 14]. Itis
giving an effect somewhat like that of the ventral valve of from the upper portion of the “Meobolus beds” at
Nisusia festinata (Billmgs), only very much reduced. The ae ee ange; India \(Geol- Survey India,
casts of the interior of the ventral valve show two strong eee
vascular sinuses and a faintly defined muscle area. This has an outline not unlike that of the
diductor scars in the ventral valve of Billingsella rominger: (Barrande) (Pl. XC, fig. 22). The
large main vascular sinuses also extend forward in the same manner in the two species. The
illustrations of the interior of the ventral valve of Wynnia warthi (Pl. LX X XIX, figs. 4 and 4a)
fail to show the outline of the muscle area as well as it is shown in the specimen represented
by figure 4,so I have inserted text figures 68A and 68A’, which are drawn from the same
specimen.

The casts of the interior of the dorsal valve show a median depression with a few radiating
lines, and a few very fine radiating lines extending from the apex a short distance forma.
In addition, by reflected light, the outlines of the anterior and posterior adductor scars can
be seen on the posterior half of the valve (Pl. LX XXIX, fig. 4c).

The longest ventral valve in the collection has a length and width of 9 mm. The dorsal
valve is a little shorter.

a Prior to the definition of the genus Wynnia the type species was placed under Qrthis [Waagen, 1891, p. 102.

ile CAMBRIAN BRACHIOPODA.

Observations.—Waagen [1891, p. 102] describes this shell at length and also gives a num-
ber of illustrations that are more or less diagrammatic. Through the courtesy of Doctor
Holland, the director of the Geological Survey of India, I have been able to study the type
specimens. I can not see as much in them as Waagen did, but as far as my observations go
they agree with his, except that the characters shown on the specimen represented by his
figure 15 [1891, Pl. I] and figure 1 [1891, Pl. II] appear to me to be the result of fracture caused
by compression of the original shell and not to be muscle scars, etc., as interpreted by Waagen
[1891, Pls. I and I].

The differences between this shell and the nearest known forms are mentioned under the
description of the genus (see p. 771).

The specific name is given in honor of Dr. H. Warth, of the Geological Survey of India.

ForMATION AND LOCALITY.—Middle Cambrian: (357d [Waagen, 1891, p. 104]) “Concretionary shales of the
Khussak group”’ at several localities between Chél Hill and Kiura (Khewra), eastern part of Salt Range, India.

Subfamily EOORTHIN® Walcott.

Genus EOORTHIS Walcott.
[fec, dawn; and épAdc, straight.]

Not Plectorthis Hatt and Ciarke, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, pp. 194-195. (Characterized
as a new genus; see below for copy. This genus, as now restricted, is not known to occur in the Cambrian.)

Orthis (Plectorthis) Waxcorr [not (Haun and CrarKe)], 1905, Proc. U.S. Nat. Mus., vol. 28, pp. 257-259. (Original
characterization copied and genus discussed somewhat as below.)

Plectorthis GRABAU and SHIMER (in part) [not Haun and CrarKe], 1907, North American Index Fossils, vol. 1, pp.
250 and 251. (Characterized. Includes both true Plectorthis and Eoorthis.)

ELoorthis Waxcorr, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, pp. 102-104. (Described and discussed as below
as a new genus.)

Loorthis Waucotr, 1908, idem, vol. 53, No. 4, Pl. XI, and pp. 142 and 148. (Classification of genus.)

In their subdivision of the genus Orthis Dalman, Hall and Clarke [1892c, p. 192] restricted
the genus Orthis to the group of which Orthis callactis Dalman is the type, and, among American
forms, Orthis tricenaria of the Trenton and Hudson faunas. These forms show the existence
of a transverse apical plate in the delthyrium of the ventral valve. The name Plectorthis
was proposed for a second group, of which Orthis plicatella was made the type (Pl. XCVI, figs.
4, 4a), and of this the authors [1892c, p. 194] say:

This is a persistent form, which in American faunas, so far as known, is limited to the Trenton and Hudson River
formations. While it retains the strong external ribs of the typical Orthis, these are not invariably simple (0. fissicosta
Hall; O. triplicatella Meek; O. equivalvis Hall [not Davidson]; O. jamest, Hall) (Pl. XCVI, figs. 5,5a-c). The cardinal
area of the pedicle valve is comparatively low and the valves are subequally convex. In the interior, the character
of the muscle scars, dental lamellee and cardinal process is essentially the same as in group I (Orthis), and the minute
structure of the shell appears to be in precise agreement with that of O. calligramma though no evidence of tubulose
costz has been observed. In Orthis jamesi, which is placed in this association, there is occasionally a deviation toward
the resupinate contour exemplified in group IV (Orthis subquadrata) and group V (Orthis sinuata).

In the Cambrian faunas I find a group of species intermediate between the typical forms
of Billingsella and of Orthis, as limited by Hall and Clarke [1892c, p. 193], which I have referred
for a long time to Hall and Clarke’s Plectorthis, placing that genus as a subgenus of Orthis.

a The synonymy for this genus does not give a complete record of the various genera under which the species now included in Hoorthis were
formerly placed; it gives only those references in which the genus is discussed or described. To complete the record for the species taken up in
this monograph the following mere generic references are listed:

Orthis de Verneuil and Barrande [1860, p. 532]. Orthisina ? Matthew [1892, p. 49].

Orthis Kjerulf [1865, p. 1). Strophomena Matthew [1893, p. 102].

Orthis Barrande [1868a, p. 99; 1868b, p. 690]. Orthis Pompeckj {1896a, p. 4; 1896b, p. 514].
Orthis Meek [1870, p. 425; 1872, p. 295]. Rafinesquina ? Schuchert [1897, p. 338].
Orthis Mallada [1875, p. 31]. Orthis Kayser [1897, p. 280].

Orthis Kayser [1876, p. 8]. Orthis ? Walcott [1899, p. 451].

Orthis Remele [1881, p. 69]. Orthis Pompeckj [1902, p. 7].

Orthis Brogger [1882, p. 48]. Orthis Weller [1903, p- 113].

Orthis Kayser [1883, p. 34]. Orthis ? Etheridge [1905, p. 249].

Orthis Remele [1885, p. 6]. Orthis (Plectorthis) Walcott [1906, p. 570).
Orthis Roemer [1885, pp. 35, 37, and 38]. Orthis (Plectorthis) Moberg and Segerberg [1906, p. 69].
Orthis Winchell [1886, p. 317]. Nisusia Walcott [1908d, p. 97] (by mistake).
Orthis Gagel [1890, pp. 10 and 34].

BILLINGSELLID A. 7713

This Cambrian group of shells which I now refer to a distinct genus may be defined as follows,
the type of the genus being “Orthis remnicha”’ Winchell (Pls. XCI and XCII):

Diagnosis.—Shells subquadrate to transversely elongate; with or without median fold
and sinus; valves subequally convex. Hinge line straight, usually forming nearly the greatest
diameter of the shell. Cardinal extremities broadly angular, rarely acuminate. Surface with
radiating ribs and striz which may be crossed by concentric growth lines and strie. The ribs
increase by interpolation.

The ventral valve has the umbo more or less elevated over a hinge line, the apex acute
and usually incurved. The area is rather broad, flat or incurved, and transversely striated.
Teeth short and supported by dental plates that extend to the bottom of the valve, bounding
a space (pseudospondylhum) including the main vascular sinuses and area of attachment of
the adductor muscle scars. Delthyrium open or partly closed by a convex deltidium. The
adductor muscle scars are included within a narrow median area beneath the umbo on each
side of the median line, and the diductors in a more or less flabelliform area outside of the
main vascular sinuses. Pedicle scars unknown.

Dorsal valve with low umbo and slightly incurved apex; area well developed, with a
broad delthyrium. Deltidial cavity with a straight, simple, cardinal process. Dental sockets
small, with short crura. The adductor muscle scars are small, the anterior being nearer the
median ridge, which usually extends forward from the base of the cardinal process.

Shell structure dense, with a minutely granular groundmass. Sections vertical to the
outer surface, however, show a few laminations of growth, but no fine fibers; sections on the
plane of the surface show a few coarse irregular fibers resembling matted wood pulp; a dense
granular groundmass that is penetrated here and there by irregular openings of varying size.
The openings or pores appear to be confined to one or more lamellz of the shell and not to
pass through it from inner to outer surface, as in Orthis (Dalmanella) parva and allied punctate
orthoids. The openings are usually indicated by minute scattered dark spots.

Type.—Orthis remnicha Winchell.

Observations.—The Cambrian species referred to Hoorthis have relatively thin shells that
retain on the interior surfaces but slight traces of the muscle scars and vascular markings,
except in the umbonal cavity. Hoorthis may be distinguished from Orthis (s.s.) by (1) its ribs
increasing by interpolation; (2) its strongly defined pseudospondylium; (8) its relatively thin
shell; and (4) its dense, nonfibrous shell structure. The last three characters also distinguish
it from Plectorthis and other subgenera of Orthis. Hoorthis may be considered as the possible
connecting link between Billingsella and the orthoids of the Ordovician.

The geological range of Eoorthis is from the upper portion of the Middle Cambrian through
the Upper Cambrian and into the lower portion of the Ordovician.

Two of the species from strata referred to the Middle Cambrian are represented by material
too imperfect for specific description; they occur with Paradozides in Bohemia, and it is not
improbable that they will be found to belong to some other genus. The remaining one of
the three species referred to the Middle Cambrian is EF. wichitaensis, which occurs in the upper
portion of the Middle Cambrian and base of the Upper Cambrian, and E. hastingsensis, which
occurs in the Middle Cambrian (Paradozxides zone).

EoorTHIS AGRESTE (Walcott). —
Plate LX X- XIX, figures 6, 6a.
Orthis (Plectorthis) agreste Watcortt, 1906, Proc. U.S. Nat. Mus., vol. 30, p.570. (Described as below as a new species.)

Shell transverse, subsemicircular; a ventral valve 9 mm. in length has a width of 12 mm.
and a hinge line 10.5 mm. in length; ventral valve moderately and regularly convex, with the
apex curved down to an area that is slightly inclined forward from the hinge line. The details
of the cardinal area are unknown.

774 CAMBRIAN BRACHIOPODA.

Surface marked by rounded radiating ribs and interspaces, 6 ribs in a space of 3 mm.
near the front margin; a few of the ribs bifurcate, but most of them extend from the umbo
to the front margin; the ribs are crossed by fine concentric strie and strong lines of growth.

Observations.—This shell is characterized by its regular convexity and the uniformity of
the rounded, radiating ribs.

ForMATION AND LOCALITY.—Middle Cambrian: (€28) Upper part of the thin-bedded gray limestone at the base
of the Changhia formation [Blackwelder, 1907a, p. 32 (first list of fossils), and fig. 6 (bed 20), p. 25] 1 mile (1.6 km.)
east-southeast of Changhia, Shantung, China.

HKoorruis ATAVA (Matthew).

Plate XCV, figures 7, 7a—b.

Strophomena atava MarruEw, 1893, Trans. Roy. Soc. Canada for 1892, Ist ser., vol. 10, sec. 4, No. 7, pp. 102-103, Pl.
VII, fig. 8a-f. (Described and discussed as a new species; see below for copy. The specimens represented
by figs. 8c, 8a, and 8b are redrawn in this monograph, Pl. XCV, figs. 7, 7a-b, respectively.)

Rafinesquina? atava (Matthew), ScucHeErt, 1897, Bull. U. 8. Geol. Survey No. 87,-p. 338. (Merely changes generic
reference.)

Orthis (Plectorthis?) atava (Matthew), Watcorr, 1905, Proc. U.S. Nat. Mus., vol. 28, pp. 259-260. (Original descrip-
tion copied and species discussed as below.)

Strophomena? atava Matthew, Moprre and Szcrrpere, 1906, Medd. fran Lunds Geol. Faltklubb, Ser. B, No. 2
(Aftryck ur K. Fysiografiska Sallskapets Handl., N. F., Bd. 17), Pl. II, figs. 7,7a-b. (Notext reference. Figs.
7, 7a-b, in common with the remaining figures on Pl. II of Moberg and Segerberg’s paper, were copied from
a preliminary photograph of Pl. XCV of this monograph.)

The original description by Matthew follows:

Narrow semicircular. Valves slightly arched, rather wider than the hinge line, compressed at the cardinal
angles; sides of the valves nearly straight behind, regularly rounded in front. ;

Ventral valve moderately convex, highest and somewhat angulated at the middle of its length. Umbo incon-
spicuous and appressed to the very narrow area.

Dorsal valve somewhat concave, especially toward the umbo, which is depressed to the general level of the
valve.

The interior of the ventral valve has characters intermediate between those of Orthis and Strophomena. The
ridges inclosing the cardinal muscles are shorter and closer at their extremities than in Strophomena, and the scar of
the adductor muscle is broader and shorter, but extends halfway to the front of the valve. There is a low, sharp
ridge at the umbo between the branches of the posterior cardinal muscle, and the ventral cavity is faintly outlined
in front. Another cast of the ventral valve of a larger individual, perhaps of this species, shows the impressions of
the muscles more distinctly; in this the impression of the adductor muscle is much nearer to the hinge, being about
two-thirds from the front of the valve. There is a low callus in front of the imprint of the adductor muscle.

A partly decorticated example of the dorsal valve exhibits a small bifid scar at the hinge line, due to the adductor
muscle. ‘There is no median ridge, such as is found in Orthis, the median sinus being almost obsolete. In front of the
impression of the adductor muscle is a small, low callus.

Sculpture: This consists of sharply raised, rounded, radiating ridges, slightly crenulated by obscure, transverse
lines. These ribs are of varying size, every third or fifth rib being larger than the others. These large ribs extend
outward from the umbo, and the smaller ones are intercalated between them, or spring from them. On the dorsal
valve there are two main ribs in the sinus of the valve and three others extending to the lateral margins; smaller ribs
are intercalated between these. On each side of the group of ribs on the middle third of the shell are four fainter,
but more strongly arched groups of ridges which throw off minor ridges at the back, directed toward the lateral mar-
gins. On the ventral valve the small ribs are almost all intercalated and do not spring from the back of the primary
ribs, as in those of the dorsal valve.

Size: Length, 12 mm.; width, 14mm. Height of area of dorsal valve, 0.5 mm.; of ventral valve, 1 mm. A
valve supposed to be of this species is 15 mm. long and 19 mm. wide.

Observations.—With the available data this species appears to be quite as near to Hoorthis
as any described genus. It does not appear to belong with the typical forms of Strophomena
or Rafinesquina. The surface ribs, increasing by interpolation, and possibly bifurcation, and the
form of the pseudospondylium in the ventral valve, strongly suggest a relationship with Hoorthis.
It will probably require better preserved material to determine satisfactorily the correct
generic reference for the species.

FoRMATION AND LOCALITY.—Upper Cambrian: (308a [Matthew, 1893b, p. 103]) Dark shales of division C3a of
Matthew’s section of the St. John formation, Navy Island, St. John Harbor, St. John County, New Brunswick, Canada.

BILLINGSELLIDA. 7175

EoortHIs BAVARICA (Barrande).

Plate XCVII, figure 4.

Orthis bavarica BARRANDE, 1868, Faune silurienne des environs de Hof, en Baviére, p. 99, fig.76. (Described in French
as a new species; see below for translation. Fig. 76 is reproduced in this monograph, Pl. XCVII, fig. 4.)

Orihis bavarica BARRANDE, 1868, Neues Jahrb. fiir Mineralogie for 1868, p. 690, unnumbered plate, fig. 76. (Copy
of preceding reference.)

Orthis sp., Pomprcxs, 1896, Tremadoc Fossilien bei Hof, p. 4. (Discussed in German; gee below for statement of
probable sainHaneitis, )

The original description by Barrande follows:

This very rare species is only represented by two specimens, reduced to a single valve, of which the less imperfect
of the two is figured. It has been deformed by compression, but we recognize that it represents the ventral valve,
the beak of which appears remarkably acute and projecting, doubtless by reason of compression. This valve shows
a barely indicated sinus, very shallow, but rather broad on the frontal contour. The surface is ornamented with
projecting longitudinal strize, close together, most of which end at the beak, but some are bitureated i in their exten-
sion. A trace of some concentric striz is seen.

Length, 14 mm.; breadth, somewhat reduced by compression, 9 mm.

Pompeckj [1896a, p. 4] mentions the finding of two impressions of a species of Orthis
agreeing in form with H. bavarica (Barrande) at Neuhof, near Hof. The species differs in
having a sharper, higher rib intercalated between every three or four finer ribs, while the ribs
of E. bavarica are all equally strong. The variation in the strength and number of the ribs

species of Koorthis is often so great that it may be that the form mentioned by Pompeckj
[1896a, p. 4] will prove to be only a variation of Hoorthis bavarica.

From the description and illustration, I think this species should be referred to Eoorthis.

ForMATION AND LOcALITY.—Passage beds between the Upper Cambrian and the Ordovician: (308¢ [Barrande,
1868a, p. 99|) suburbs of Hof; and (303f [Pompeckj, 1896a, pp. 7 and 8]) railway cut near Schellenberg, a little dis-
tance back of the railway station at Neuhof, near Hof; both in Bavaria, Germany.

KooRTHIS CHRISTIANI® (Kjerulf).

Plate XCV,-figures 1, la—h.

Orthis christianizx KsERULF, 1865, Veiviser ved Geologiske Excursioner i Christiania Omegn, p. 1 and figs. 8a-c, p. 3.
(Locality given in Norwegian.)

Orthis christianie Kjerulf, BR6GGER (in part), 1882, Die silurischen Etagen 2 und 3, p. 48, Pl. X, figs. 14a-c. (Men-
tions specimens from: both the Ceratopyge slate and Ceratopyge limestone and thus probably includes the two
species, Hoorthis christianiz and E. daunus. See below.)

Orthis (Plectorthis) christianite (Kjerulf), Waucorr, 1905, Proc. U. S. Nat. Mus., vol. 28, pp. 260-261. (Discussed
somewhat as below.)

Orthis (Plectorthis) christianiz (Kjerulf), Moprere and SEGERBERG (in part), 1906, Medd. fran Lunds Geol. Faltklubb,
Ser. B, No. 2 (Aftryck ur K. Fysiografiska Sillskapets Handl., N. F., Bd. 17), p. 69, Pl. II, figs. 1, lah; Pl.
III, figs. 12 and 13. (Described and discussed in Swedish. Includes Hoorthis daunus and E. tullbergi. Figs.
1, la—h, in common with the remaining figures on Pl. II of Moberg and Segerberg’s paper, were copied from a
preliminary photograph of Pl. XCV of this monograph. )

The general form and character of this shell as it occurs in the shales are shown by the
figures illustrating it. It appears to differ from any described species in the peculiarity of the
bifurcation, of the radiating ribs. In all the species I have referred to Hoorthis the increase
in the number of ribs is by interpolation and not by true bifurcation. In E. christianie the
increase is by both methods, as shown by figures la, 1b, and 1g. The reference to Hoorthis
is somewhat doubtful, as there are not sufficient data to base a reference on the characters of
the interior, cardinal areas, or convexity of the valves.

I have received a large number of specimens from Norway and Sweden labeled ‘‘Orthis
christianie.”” After a study of all the available material only the shells from the argillaceous
shale of Russelékken and Téien, Norway, and of Oeland Island, Sweden, appear to belong to
the species. The shells in the Ceratopyge limestone (Hoorthis dawnus) have ribs that increase
in number by interpolation of ribs in the interspaces between the older ribs, and a second
species (H. wimant), that occurs in both the shale and the limestone, has simple ribs with few

776 ~ CAMBRIAN BRACHIOPODA.

interpolated beyond the umbo. Another transverse form has simple strong ribs that increase
in number by the interpolation of a few new ribs.

Brégger’s illustrations of this species [1882, Pl. X, figs. 14a-c] suggest H. dawnus more
than the typical form of E. christianiz, as I understand and interpret it. “‘Orthis parva”
Dalman (PI. XCVI, figs. 6, 6a-g) has sometimes been referred to E. christiamz.

Gagel [1890, p. 34] described the form usually found in the limestone, stating that the
surface is covered with strong, dichotomous ribs. He found it in drift blocks of the Ceratopyge
limestone near Belschwitz, East Prussia; and of glauconitic limestone near Prussio Holland,
and near Wehlau, East Prussia, Germany.

Roemer [1885, p. 36] aallls attention in his description of the drift in the North Gout
plain to the fact that Remelé [1885, pp. 695-698] was the first to identify with certainty blocks
of the Ceratopyge limestone of Sweden in the drift of Germany, the presence of a form like Z.
christianiz being part of the evidence. This shell is probably H. dawnus. Roemer [1885,
p. 36] states in description of the Ceratopyge limestone that a small ‘‘Orthis (2? Orthis christianiz
Kjerulf)”’ predominates.

The specific name is derived from Christiania, Norway.

ForRMATION AND LOCALITY.—Upper Cambrian: (323x) Ceratopyge slate, at Russelékken; and (328y) Ceralonyge
slate at Téien; both near Christiania, Norway.

(810d) Ceratopyge slate, at Borgholm, Oeland Island, Sweden.
(309e) Shales of the Acerocare zone at Akarpsmélla, midway between Kageréd and Réstéanga, Province of Mal-

moéhus, Sweden.

Eoortuis pAuNUS (Walcott).

Plate XCV, figures 2, 2a-c.

Orthis sp. REMELE, 1881, Zeitschr. Deutsch. geol. Gesell., Bd. 33, p. 696. (Characterized and compared in German.)

Orthis christianiz BROGGER (in part) [not Kservuur], 1882, Die silurischen Etagen 2 und 3, p. 48, Pl. X, figs. 14a-c.
(Mentions specimens from both the Ceratopyge slate and Ceratopyge limestone and thus probably includes the
two species, Hoorthis christianiz and #. dawnus.)

Orthis christianie RoEMER [not KyERuLF], 1885, Paleontologische Abhandlungen von Dames und Kayser, Bd. 2, Hit. 5,
pp. 36, 37, and 38. (Mentioned in German, in review of literature.)

Orthis christianix RemeLé [not Krerur], 1885, Katalog der beim intern. Geologen-Congress zu Berlin ausgestellten
Geschiebesammlung, p. 6. (Locality mentioned.)

Orthis christianie GAGEL [not Kyeru Fr], 1890, Beitr. zur Naturkunde Preussens, von Physikal.-oekonom. Gesell.
Kénigsberg, No. 6, pp. 10 and 34, Pl. Il, figs. 22a-b. (Described and new localities mentioned in German.)

Orthis christianiz Pomprcks [not Kyeruxr], 1902, Neues Jahrb. fiir Mineralogie, Bd. 1, p. 7. (Occurrence mentioned,
in German.)

Orthis (Plectorthis) daunus Waxcort, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 261. (Characterized as a new species.)

Orthis (Plectorthis) dawnus Walcott, Moprre and SecrrBerc, 1906, Medd. fran Lunds Geol. Faltklubb, Ser. B, No. 2
(Aftryck ur K. Fysiografiska Sillskapets Handl., N. F., Bd. 17), p. 69, Pl. II, figs. 2, 2a-c. (Characterized in
Swedish. Figs. 2,2a-c, in common with the remaining figures on Pl. II of Moberg and Segerberg’s paper, were
copied from a preliminary photograph of Pl. XCV of this monograph.)

The illustrations show the principal characters of this species. It differs from Hoorthis
christianiz in having simple ribs that increase in number toward the front and lateral margins
of the shell by interpolation of new ribs; no true bifurcation of the ribs was observed. A strong
median sinus occurs on specimens of the dorsal valve in both shale and limestone. The shell
is fibrous and impunctate. No traces have been seen of the fine, rounded, radiating striz that
occur on the broader ribs and interspaces of E. christianiz. This species differs from EH. wimana
in its more transverse form and less simple ribbing of the shell.

Moberg and Segerberg [1906, pp- 69- 70] seeeul this form as one of the variations of E..
christianiz. This may be a correct view, but I am not prepared, after a careful study of the
material before me, to accept it. To support such an interpretation we should find, in a very ~
full series of E. christianie from the same bed or matrix, the gradations or varieties that I have
named tullbergi: and daunus.

FoRMATION AND LOCALITY.—Passage beds between the Upper Cambrian and Ordovician: (386) Drift
blocks of Ceratopyge limestone near Belschwitz; (386a) drift blocks of ‘‘Glauconite limestone” near Prussian Holland,

BILLINGSELLIDA. Uae

90 miles (145 km.) south-southwest of Konigsberg; and (386b) drift blocks of ‘‘Glauconite limestone” near Wehlau,
30 miles (48 km.) east of Konigsberg; all [Gagel, 1890, p. 34] in Hast Prussia, Germany.

(823z) Ceratopyge limestone at Toien, near Christiania; and (8x) Ceratopyge limestone at Slemmestad, about 3 miles
(4.83 km.) southwest of Christiania; both in Norway.

(328h) Blue Ceratopyge limestone at Vestfossen; and (281) lower part of the Ceratopyge limestone at Vestfossen;
both [Brégeger, 1882, p. 17] 10 miles (16.1 km.) west-southwest of Christiania, Norway.

(310j) Ceratopyge limestone at Borgholm; and (310 [Moberg and Seusinere, 1906, description of Pl. I1]) Ceratopyge
limestone (zone 4) at Ottenby; both on Caled Island, Sweden.

EoortTHIs DESMOPLEURA (Meek).

Plate XCVI, figures 1, la—.

Not Orthis coloradoensis SHumARD, 1860, Trans. Acad. Sci. St. Louis for 1856-1860, vol. 1, p. 627. (Referred in this
monograph to Billingsella.)

Orthis coloradoensis Mprx [not SHumMARD], 1870, Proc. Am. Philos. Soc., vol. 11, No. 84, p. 425. (Described as a new
species.)

Orthis desmopleura MrEx, 1872, U. S. Geol. and Geog. Terr., Geol. Survey Wyoming, Prelim. Rept., p. 295. (Merely
proposed as a new specific name, coloradoensis being preoccupied.)

Orthis (Plectorthis) desmopleura (Meek), Waxcorr, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 261. (Characterized.)

This shell has the general form and external characters of EH. wichitaensis (Walcott). It
differs in being less convex and in the details of the radiating ribs. The illustrations of the
two species will serve as a basis of comparison. Hoorthis desmoplewra differs from EH. remnicha
(N. H. Winchell) in its uniformly smaller size, less convexity, and in the details of the radiating
ribs. The ribs have a wide range of variation, but when from the same character of matrix they
are all of the same type and the shells grade from one to the other. The ventral valves of
young shells 2 to 3 mm. long are highly convex and usually appear to be a little longer than wide;
if in such shells the surface striz are in sharply elevated fascicule, the result is to all appearances
a rhynchonelloid shell.

The interior of the ventral valve shows a narrow area, broad delthyrium, spondylium
almost free from the bottom of the valve, and a median septum that may have supported the
front end of the spondylium. In young and strongly convex shells the spondylium is narrow
and very strongly defined. The narrow area of the dorsal valve is divided by a broad delthy-
rium, in the center of which is a very slightly developed cardinal process.

The Wyoming variety of this species occurs in abundance in the Bighorn Mountains.
The specimens illustrated on Plate XCVI show the characteristic features of the species as it
occurs in Colorado, and also some phases of it not observed there. The typical form is
illustrated by figure 1h. For the variety the name of EL. desmopleura nympha is used (PI.
XCVI, fig. 2).

Eoorthis hamburgensis (Walcott) [1884b, p. 73] is closely related to . desmopleura and may
be identical with it. Hoorthis melita (Hall and Whitfield) [see Lepteena melita Hall and Whit-
field, 1877, p. 208] from the Pogonip Lower Ordovician limestone is near to the less convex,
more evenly striated forms of H.desmopleura. It is probably not more than a variety of the
latter. Schuchert’s reference of the species L. melita to Dalmanella [1897, p. 202] does not
appear to be correct, as it has the pseudodeltidium of Hoorthis.

FORMATION AND LocALity.—Lower Ordovician: (3860f) Siliceous limestone at Glen Eyre, Queens Canyon, north-
east of Manitou; (360a) red siliceous limestone on west side of Trout Creek below Bergen Park, 7 miles (11.2 km.)
north-northwest of Manitou; (186 and 186a) near line of contact between red and gray Ordovician limestone, in
siliceous red limestone about 30 feet (9.1 m.) above.the pre-Cambrian rocks, Williams Canyon, Manitou; (187) red
siliceous limestone 105 to 122 feet (32 to 36.7 m.) above the pre-Cambrian rocks, 2 miles (3.2 km.) below Manitou Park
Hotel; and (360) red siliceous limestone near Colorado Springs; all in El Paso County, Colorado.

(105t) Limestone [Walcott, 1908f, p. 173] at the summit of Notch Peak, House Range, Millard County, Utah.

(185z) Limestones at the base of the Lower Ordovician [Walcott, 1908f, p. 191] in Blacksmith Fork Canyon, about
9 miles (14.4 km.) east of Hyrum, Cache County, Utah.

Passage beds between the Upper Cambrian and the Ordovician: (4g) Limestone about 1,000 feet (305 m.) above

the valley on the east side of the Fish Spring Range, just west of the high point southwest of the J. J. Thomas ranch,
Tooele County, Utah.

778 CAMBRIAN BRACHIOPODA.

Upper Cambrian: (30w) Drift. bowlder of limestone supposed to have come from 1a of the Notch Peak limestone
on Notch Peak [Walcott, 1908f, p. 175], found about 2 miles (3.2 km.) south of Marjum Pass, House Range [Walecott,
1908f, Pl. XIII], Millard County; (831) limestones in pass between the Pavant Mountains and the Canyon Range, a
few hundred yards east of the divide, on the road between Holden and Scipio, Millard County; and (54r) drift pieces
of limestone from the west slope of the Wasatch Range, east of the Lakeview ranch, about 5 miles (8 km.) north of
Brigham, Boxelder County; all in Utah.

(54b) About 1,200 feet (365.8 m.) above the Middle Cambrian and 25 feet (7.6 m.) below the top of the Upper Cam-
brian in the upper part of the limestone forming 1 of the St. Charles formation [ Walcott, 1908f, p. 191]; (54c) about
1,100 feet (335.3 m.) above the Middle Cambrian and 120 feet (36.6 m.) below the top of the Upper Cambrian, in the
central part of the limestone forming 1 of the St. Charles formation | Walcott, 1908f, p. 192]; and (54d) about 1,050 feet
(320 m.) above the Middle Cambrian and 175 feet (53.3 m.) below the top of the Upper Cambrian in the lower part
of the limestone forming 1 of the St. Charles formation [Walcott, 1908f, p. 192]; all in Blacksmith Pork Canyon, about
10 miles (16.1 km.) east of Hyrum, Cache County, Utah. ;

(158) Limestones north of Hast Gallatin River, near Hillsdale; and (340b) limestone at the mouth of Fourmile
Creek; both in the Threeforks quadrangle (U. S. Geol. Survey), Gallatin County, Montana.

(327) Arenaceous limestone east of Gold Camp, in the Caballos Mountains, New Mexico.

(14k) Limestone on Wolf Creek, 15 miles (24.2 km.) west-southwest of Sheridan, Bighorn Mountains; and (168)
limestone on north side of Tepee Creek, beside the road from Sheridan to Dome Lake, Bighorn Mountains; both in
Sheridan County, Wyoming.

(346b) Conococheague limestone, 2.75 miles (4.4 km.) south of Mercersburg, Franklin County, Pennsylvania.

Specimens that are somewhat doubtfully referred to this species occur at the following
localities:

Upper Cambrian: (152) Limestone on ridge between Churn and Cottonwood Canyons, west side of Bridger Range;
and (154) limestone in hill on west side of Dry Creek, opposite mouth of Pass Creek, about 5 miles (8 km.) north of
Hillsdale, Threeforks quadrangle (U. 8. Geol. Survey); both in Gallatin County, Montana.

Upper? Cambrian: (306) Sandy limestone on Gravel River, eastern slope of the Rocky Mountains, in the
Mackenzie River basin, British Columbia.

\ EKoorTHIS DESMOPLEURA NYMPHA (Walcott).
Plate XCVI, figure 2.

Orthis (Plectorthis) desmopleura nympha Waxcort, 1905, Proc. U.S. Nat. Mus., vol. 28, p. 262. (Characterized as below
as a new variety.)

This variety is based on strongly convex ventral valves in which the surface is marked by
fine radiating strie, separated into bands of 3 to 6 strie by stronger and more elevated striz.
Some shells show concentric lines and often ridges of growth that give an imbricated appear-
ance to the portion of the surface beyond the umbo.

ForMATION AND LOCALITY.—Lower Ordovician: (186) Near line of contact between red and gray Ordovician
limestone, in red siliceous limestone about 30 feet (9.1 m.) above the pre-Cambrian rocks, Williams Canyon, Manitou,
El Paso County, Colorado.

Upper Cambrian: (168) Limestone on north side of Tepee Creek, near the road from Sheridan to Dome Lake, Bighorn
Mountains, northern Wyoming.

Eoortuis? piABLo (Walcott).
Plate XCIII, figure 3.
Orthis (Plectorthis) diablo Waxcorr, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 262. (Described as below as a new species.)

This species is founded on a small, transverse shell that is marked by a few prominent
radiating coste that extend from the umbo to the margin of the shell. In the cast the costz
have a sharp summit and slope evenly to a narrow space between them.

A ventral valve 9 mm. in height has a width of 14 mm., which is about the average propor-
tion of the specimens in the collection. The casts of the ventral valve show a rather low area
divided by a delthyrium, the inner angles of which have a rather strong tooth. The dental
plates extend backward farther than in most species of the genus, bécoming attached to the
bottom of the valve only near the teeth, and not extending forward as in Hoorthis remnicha to
form a pseudospondylium. None of the specimens in the half dozen shells in the collection

BILLINGSELLID. 779

show the muscular or vascular markings. There may or may not be a mesial depression on
either valve. The reference of this species to Hoorthis is made with much reservation.

FORMATION AND LOCALITY.—Upper Cambrian: (81b) ‘‘St. Croix sandstone,’ near Devils Lake, Sauk Cownty; and
(83) “‘St. Croix sandstone,’’ near Trempealeau, Trempealeau County; both in Wisconsin.

Eoorruis poris (Walcott).

Plate XOVILI, figures 13, 13a.

Orthis (Plectorthis) doris WaLcott, 1905, Proc. U.S. Nat. Mus., vol. 28, pp. 262-263. (Described and discussed as below
as a new species. )

Of this species a ventral and dorsal valve occur in the collection. General form rounded
subquadrangular. Ventral valve strongly convex, with the greatest height at the umbo, from
which the beak arches over a high backward-inclining area. Dorsal valve much like the ventral
in form except that it is less convex and less elevated at the area.

Surface of both valves with numerous radiating ribs that have an angular summit and an
angular depression between them. ‘The ribs increase in number toward the front by interpola-
tion. The ventral valve has a length of 7 mm.; width, 8 mm. The dorsal valve is a little
shorter than the ventral.

Observations.—Vhis shell is not unlike Hoorthis indianola in form and surface characters.
It differs in being more convex and in the absence of a sinus or median fold on either valve.

FORMATION AND LOCALITY.—Upper Cambrian: (C64) Upper limestone member of the Kiulung group [Black-
welder, 1907a, pp. 37 and 42 (first list of fossils), and fig. 10 (bed 20), p. 38], 2.7 miles (4.3 km.) southwest of Yen-
chuang, Sintai district, Shantung, China.

EoorTHIS HASTINGSENSIS (Walcott).
Plate XCIV, figures 3, 3a-c.

Orthis (Plectorthis) hastingsensis Waucort, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 263. (Described and discussed
as below as a new species.)

Shell transversely subelliptical. Surface with numerous strong, rounded, radiating ribs
increasing in number by interpolation; the ribs appear to be broader and with narrower inter-
spaces on the ventral valve; concentric ridges and fine strie of growth are a marked feature
of the surface. A ventral valve 4 mm. in length has a width of 6 mm.; a dorsal valve 6 mm.
_ long is 10 mm. in width.

Ventral valve strongly convex, most elevated on the umbo, and without mesial fold; apex
incurved slightly over the delthyrium; area weil defined, and divided midway by a large
delthyrium; it is inclined but little from the vertical.

Dorsal valve slightly convex in young shells, and becoming more so as they increase in
size; area low and inclined backward over the hinge line.

Observations.—This species is unlike other described forms in the character of its ribs,
with the exception of Hoorthis johannensis, which it resembles very closely. Matthew [1892,
p- 49] describes the latter species as haying a very thin shell,and it is found in the Upper Cam-
brian at St. John. No interior features have been seen. Matthew [1897b, p. 170] mentions
having found fragments of Protorthis or Orthis in the phosphate nodules at Hastings Cove, too
imperfect for description.

The species. derives its specific name from its occurrence at Hastings Cove.

FORMATION AND LOCALITY.—Middle Cambrian: (21 and 2m) Limestone and superjacent shale at the base of the
Paradoxides zone {| Matthew, 1895a, p. 108], on Hanford Brook, St.John County; and (2s) limestone in upper part of
Paradowides zone, Hastings Cove [Matthew, 1898b, p. 38], on Kennebecasis Bay, 0.5 mile (0.8 km.) northeast of Torry-
burn, on the Intercolonial Railway northeast of St. John, St. John County; all in New Brunswick.

a 21 is the type locality.

780 CAMBRIAN BRACHIOPODA.

Eoortats mwpinest (Walcott).

Plate XCI, figures 3, 3a—b.

Orthis? remnicha Waucort (in part) [not N. H. Wincuexp], 1899, Mon. U. S. Geol. Survey, vol. 82, pt. 2, pp. 451-452,
Pl. LXII, figs. la and 1b (not Pl. LXI, figs. 3 and 3a, or Pl. LXII, figs.1, 1c, and1d). (Specimens now referred
to Eoorthis iddingsi were included with E. remnicha when this description was written, two being figured, Pl.
LXII, figs. la and 1b. The specimens represented by these two figures are redrawn in this monograph, Pl.
XCII, figs. 3 and 3a, respectively. The specimens represented by Pl. LXI, figs. 3 and 3a, and Pl. LXII, figs.
1, 1c, and 1d belong with Hoorthis remnicha.) : ‘

Orthis (Plectorthis) iddingsi Waxcort, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 264. (Characterized as below as a new
species.) :

General form and convexity much like that of some varieties of Eoorthis indianola. Its
surface characters also approach those of the more regularly ribbed shells of the latter species.
The principal difference between the two species is the less convexity, lower umbo, and lower
area of E. iddingsi. The interior of the ventral valve shows a short, well-defined umbonal
cavity with a strong vascular sinus on each side of it that extends well forward into the valve.

The specific name is given in honor of Prof. Joseph P. Iddings.

FORMATION AND LOCALITY.—Upper Cambrian: (302c) Shaly limestone on the south side of the Gallatin Valley, Yellow-
stone National Park, Wyoming; and (302d) limestone 200 yards (183 m.) north of the southwest corner sec. 18, T. 28
N., R. 113 W., Uinta County; both in Wyoming.

(71) Limestone in Cold Creek Canyon, Burnet County, Texas.

EoortTuis INDIANOLA (Walcott).

Plate XCIV, figures 1t, lu, 2, 2a-h.

Orthis (Plectorthis) indianola Watcortt, 1905, Proc. U. S. Nat. Mus., vol. 28, pp. 264-265. (Described and discussed
essentially as below, as a new species.)

Pectorthis indianola (Walcott), GraBau and Sumer, 1907, North American Index Fossils, vol. 1, pp. 251-252.
(Described.)

Shell small, transverse, with the cardinal extremities rounded, angular, and in some speci-
mens almost alate. Valves moderately convex, the ventral nearly twice as much so as the
dorsal; the length of the hinge line varies from slightly less than the greatest width of the
shell to one-fifth greater than the width of the shell across the center, in shells with extended
cardinal extremities.

The ventral valve may or may not have a mesial depression. In some examples the
depression is broad and rounded, and in others it is shallow with stronger ribs at each margin;
umbo somewhat elevated, and curving over toward the hinge line, beyond which it projects,
terminating in a small, incurved beak; dorsal valve considerably less convex than the ventral;
beak small and projecting slightly over the hinge line. The median sinus in the dorsal valve
varies from a broad, shallow depression to a narrow, rather deep, furrow, that gives a bilobed
appearance to the valve (Pl. XCIV, fig. 2f).

The strength and arrangement of the strong and minor radiating elevated ribs and strie
are quite variable. On some shells the ribs or strie are very fine, of nearly equal size, and
separated by grooves of about the same width (Pl. XCIV, figs. of, 2¢, and 2h). In other
examples every third or more widely separated rib is stronger and elevated above a more
or less broad interspace, marked by fine ribs or coste (Pl. XCIV, fig. 2). A few of the varia-
tions in surface are illustrated.

Almost nothing is known of the interior of the valves. Below the umbo in a few speci-
mens there is a well-marked pseudospondylium that is much like that of EL. remnicha. The
area of the ventral valve is inclined at an angle of about 65° to the plane of the margin of the
valve; it is rather low and broken midway by a strong delthyrium. The area of the dorsal
valve is low and inclined well out over the hinge line.

Observations.—Eoorthis indianola is sims as variable in its form and surface markings
as E. wichitaensis, with which it is associated at a number of localities. It differs from the latter
in its bilobed dorsal valve, more strongly incurved umbo and apex of the ventral valve, and

BILLINGSELLID. 781

the general appearance of convexity and rotundity of the ventral valve. This may be seen
by comparing the shells marked W=E£. wichitaensis with those marked X=. indianola in
Plate XCIV, figure 1u, which represents: a fragment of limestone in which the two species are
associated. When the specimens of the two species are imperfect or the young shells of £.
wichitaensis occur in association with the shells of EH. indianola it is difficult to determine
positively to which species they belong.

The specific name is derived from Indian Territory (now Oklahoma), in which the type
specimen was found.

FORMATION AND LOCALITY.—Upper Cambrian: (369) Sandstones at the base of the Elvins formation, in the eastern
limits of the town of Flat River, St. Francois County; and (369b) limestone near Potosi, Washington County; both in
Missouri.

(9t) About 170 feet (52 m.) above the porphyry contact in the limestones of the Reagan sandstone; and (9u)
about 195 feet (59.4 m.) above the porphyry contact in the limestones of the Reagan sandstone; both in the SE. 4+
NE. }sec. 2, T. 4 N., R. 13 W., about 15 miles (24.2 km.) northwest of Fort Sill, Comanche County, Oklahoma.

(9w) About 100 feet (30.5 m.) below the Arbuckle limestone, in the limestones of the Reagan sandstone, SW. 4+
sec. 17, T. 4 N., R. 12 W., about 11 miles (17.6 km.) northwest of Fort Sill, Comanche County, Oklahoma.

(12k) Limestones of the Reagan sandstone (in the section 7 miles (11.2 km.) north of Springer this horizon is about
225 feet (69 m.) above the porphyry contact and 55 feet (17 m.) below the Arbuckle limestone), on the west side of Honey
Creek, near the southeast corner of sec. 35, T. 1 S., R. 1 E., Ardmore quadrangle (U. S. Geol. Survey), Carter County;
(12n) limestones of the Reagan sandstone (in the section 7 miles (11.2 km.) north of Springer this horizon is
about 240 feet (73 m.) above the porphyry contact and 40 feet (12 m.) below the Arbuckle limestone), NW. 4 sec. 1,
T. 2S., R. 1 E., Ardmore quadrangle (U. S. Geol. Survey), Carter County; and (12p) about 225-feet (69 m.) above
the igneous rocks in the limestones of the Reagan sandstone, at the northwest extremity of the Arbuckle Mountains,
about 4 miles (6.4 km.) east of Homer, Carter County; all in Oklahoma.

(14b) Limestone on Cold Creek at north end of gorge opposite the north end of Sponge Mountain, 2 miles (3.2
lan.) south of the San Saba County line, in Llano County; and (71) limestone in Cold Creek Canyon, Burnet County;
all in Texas. -

Specimens that are doubtfully referred to this species occur at the following locality:
Upper Cambrian: (68) Limestone on Packsaddle Mountain, Llano County, Texas.

EoorTHIS JOHANNENSIS (Matthew).

Plate XCVII, figures 10, 10a.

Orthisina(?) johannensis MatrHEw, 1892, Trans. Roy. Soc. Canada for 1891, Ist ser., vol. 9, sec. 4, No. 5, pp. 49-50,
Pl. XII, figs. 13a—c. (Described and discussed as a new species; see below for copy. The specimens repre-
sented by figs. 13a—c are redrawn in this monograph, Pl. XCVII, figs. 10 and 10a, respectively.)

Orihis (Plectorthis) johannensis (Matthew), Wancorr, 1905, Proc. U. S. Nat. Mus., vol. 28, pp. 265-266. (Original
description copied and species discussed as below.)

The original description by Matthew follows:

Shell subquadrate, doubly convex, rather flat, very thin.

Dorsal valve depressed at the sides and front, and having a broad, shallow median sinus. The valve is about
one-quarter wider than long, and the hinge line is nearly as long as the length of the shell. Umbo slightly elevated,
hinge plate weak and thin.

Ventral valve depressed at the sides, and having a few median ridges running from the umbo to the front of the
shell. This valve is somewhat geniculated at two-fifths of its length from the umbo, and from the bend faintly raised
ridges diverge to the anterior angles of the shell; behind the geniculation the surface of the shell is marked by faint
undulations similar to those of Strophomena rhomboidalis.

The umbo is not prominent, but the back of the valve is regularly curved and the area rather low.

Closely set strize radiating from the umbo and faint concentric strie mark the shell.

Length of the ventral valve, 9mm.; width, 10mm. Length of dorsal, 8 mm.; width, 10 mm.

This species has a low umbo for an Orthisina, and in its form recalls the genus Strophomena, as also do the con-
centric undulations that are found on the back of the ventral valve. The dorsal valve, however, is convex, and the
area of this and the ventral valve too high fora Strophomena. It does not appear to agree with any described species
of Orthisma. It resembles O. orientalis White somewhat in form, but is not so long nor so wide at the hinge. From
O. pepina Hall it differs in its lower umbo and area, shorter hinge, and smoother surface. It approaches more closely
to the form from the Potsdam sandstone of the West, figured by Hall [1863, Pl. VI, fig. 22], but not named, except
as ‘‘ Strophomena or Strophodonta.”’ :

Doctor Matthew very kindly sent me the types of this species. There is little that can
be added to his very complete description, but I had two enlarged drawings made to illustrate

782 CAMBRIAN BRACHIOPODA.

the character of the surface more fully than the illustrations given py Matthew [1892, Pl. XII,
figs. 13a-c]. As far as known, the characters of the shell are those of the group of species
referred to Hoorthis.

FORMATION AND LOCALITY.—Upper Cambrian: (308b [Matthew, 1892, p. 49]) Limestone lentiles in black shales
of Division G3a of Matthew’s section, Germaine Street, St. John, St. John County, New Brunswick.

EoortTuis KAYSERI (Walcott).

Plate XCVII, figures 6, 6a-b.

Orthis (Plectorthis) kayseri Waicort, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 266. (Characterized as below as a new
species. )

This is a larger shell than Hoorthis linnarssoni (Kayser), with which it is associated. Its
surface is marked by numerous fine radiating strie, four or five in a distance of 1 millimeter,
and the inner layers of the shell appear to be minutely punctate. The ventral valve is more
convex than the dorsal, the latter being nearly flat in young shells. Nothing is known of- »
the interior, except one cast of the pseudospondylium of the dorsal valve, which is larger in :
proportion than that of £. linnarssont.

The largest ventral valve has a length of 14 mm.; width, 20 mm.

This species belongs in the group of Hoorthis represented by E. desmoplewra (Meek) and
E. linnarssoni (Kayser).

The specific name was given in honor of Dr. E. Kayser.

eT a

FoRMATION AND LOCALITy.—Upper Cambrian: (C64) Upper limestone member of the Kiulung group | Blackwelder,
1907a, pp. 87 and 42 (first list of fossils), and fig. 10 (bed 20), p. 38], 2.7 miles (4.3 km.) southwest of Yenchuang, Sintat
district, Shantung; (C68) upper part of the Chaumitien limestone [Blackwelder, 1907a, p. 36 (part of third list of
fossils)], at Chaumitien, Changhia district, Shantung; and (C74) a dense blue dolomitic limestone at the top of
the Kichou limestones [Willis and Blackwelder, 1907, pp. 139 and 145 (5th list of fossils)], 4 miles (6.4 km.) east of
Fanglanchon, Shansi; all in China.

Eoortuis KicHOUENSIS (Walcott).
Plate LX XXIX, figure 5.

Orthis (Plectorthis) kichouensis Watcorr, 1906, Proc. U. 8. Nat. Mus., vol. 30, p. 070. (Described as below as a new
species. )

This species is represented by one specimen of the dorsal valve. The outline of the shell
is transversely rounded subquadrilateral; length, 9 mm.; width, 13 mm.; the highest point
‘above the plane of the margin is about 3 mm.; the shallow median sinus, which begins at the
umbo above the hinge line, gradually widens toward the front margin; the umbo curves over
beyond the hinge line and then under to the beak, which apparently is at or a little over the
upper edge of a very narrow area.

Surface marked by numerous radiating, rounded ribs, with narrow interspaces, 7 ribs in a
distance of 45 mm.; a few bifurcations of the ribs occur at irregular intervals between the
apex and the margins. There are no traces of concentric striz; if on the shell originally, they
~have been removed by the wearing off of the outer surface.

Observations.—This species is distinguished from all other species by the strong, incurved
umbo and rounded ribs with narrow interspaces.

The specific name was derived from the Kichou formation, in which the species occurs.

FoRMATION AND LOCALITY.—Middle Cambrian: (C75) Limestone near the base of Kichou formation [Willis and
Blackwelder, 1907, p. 143], 4.5 miles (7.2 km.) south of Wutaihien, Shansi, China.

EoorTHIS LINNARSSONI (Kayser).

Plate XCVII, figures 5 and 5a.

Orthis linnarssoni Kayser, 1883, China, by Richthofen, vol. 4, p. 34, Pl. III, fig. 1. (Described and discussed in
German as a new species, see p. 783 for translation. Fig. 1 is reproduced in this monograph, Pl. XCVII, fig. 5a.)

BILLINGSELLID. 783

“

Orthis (Plectorthis) innarssoni (Kayser), Watcorr, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 266. (Original description
copied and species discussed as below.)
The original description by Kayser follows:

Shell semielliptical in outline, broader than long, with hinge edge straight, corresponding to the greatest breadth
ofthe shell. Large (ventral) valve moderately convex. Small (dorsal) valve slightly arched, with a sinus which devel-
ops at the umbo and grows quite broad and deep toward the edge. Umbo of ventral valve small, area very low.
Surface of shell covered with rather sharp ribs, exceedingly variable in strength, separated by narrow furrows. By
reason of repeated splitting, which begins close to the umbo, the ribs appear more like bundles of ribs. On the matrix
these bundles appear as broad, obtuse-angled folds, which, owing to repeated marginal splitting in even a higher
degree than on the shell itself, appear as bundles of ribs of very unlike strength. When the surface is well preserved,
a delicate concentric growth striation is perceptible.

> Kayser [1883, p. 35] compares this shell with “Orthis hicksi” Salter and “O. exporrecta”’
Linnarsson, on account of the surface characters. It does not appear to be very closely related
to either species, but it is in many respects allied to Hoorthis desmopleura (Meek) and E.
wichitaensis (Walcott).
The specific name is given in honor of Dr. J. G. O. Linnarsson.

FORMATION AND LOCALITY.—Upper Cambrian: (C64) Upper limestone member of the Kiulung group [Black-
welder, 1907a, pp. 37 and 42 (first list of fossils), and fig. 10 (bed 20), p. 38], 2.7 miles (4.3 km.) southwest of Yenchuang,
' Sintai district; and (C67) stream gravels used in making the railroad grade 0.33 mile (0.5 km.) west of the west
city gate at Tsinan; both in Shantung, China.
(832a) [Kayser, 1883, p. 34] Taling, Liaotung, China.

~ FEoortTHIS NEWBERRYI Walcott.
Text figures 69A—D.

Hoorthis newberryi Watcorr, 1908, Smithsonian Mise. Coll., vol. 53, No. 3, p. 105, Pl. X, figs. 6 and 6a. (Described
and discussed as below as a new species. Figs. 6 and 6a are copied in this monograph as figs. 69B and 69D.)
Shell transversely subelliptical, with the cardinal extremities obtusely angular; valves
moderately convex, with the hinge line a little shorter than the greatest width of the valves.
The only ventral valve in the collection show-
ing a mesial fold (fig. 69A) is a small exfoli-
ated shell that is somewhat doubtfully referred
to the species. ‘Two large valves, one of which
is illustrated by figure 69B, have the posterior
margin extended beyond the hinge line, with a
short incurved beak; a broad, shallow median
sinus begins in front of the umbo and widens
to nearly one-third of the width of the valve
at the frontal margin. On a shell 5 mm. in
length the sinus is very shallow; area un-
known. The dorsal valve is almost uniformly
convex and without a mesial sinus or fold; the
front margin arches upward a little to provide
for the extension of the margin of the ventral

FIGURE 69.—oorthis newberryi Walcott. A, Partly exfcliated ventral

valve caused by its broad median SIOUS; beak valve (U.S. Nat. Mus. Cat. No. 52350a).. B, Ventral valve, the type
minute and marginal; area unknown. 2 specimen, preserving De. of the surface characters (U. S. Nat.
B “0 : Mus. Cat. No. 52350b};~ C,,Small exfoliated ventral valve (U. S.
‘ Surface tate ked by concentric lines and Nat. Mus. Cat. No. 52350R).41D, Partly exfoliated dorsal valve (U.S.
ridges of growth and small, rounded, radiating Nat. Mus. Cat. No. 523508). 6
ribs, with two or three smaller ribs between The specimens represented are from Locality 54c, Upper Cambrian
7

F i limestone of the St. Charles formation, in Blacksmith Fork Canyon,
each two larger ridges. The shell structure is east of Hyrum, Cache County, Utah. Figures 69B-and 69D are copied

fibrous and impunctate as far as can be de- ‘om Walcott [1908d, Pl. X, figs. 6 and 6a).

termined from the material available for study. The largest ventral valve has a length of 14

mm.; width, 18mm. A dorsal valve 15 mm. in length has a width of 18 mm.
Observations.—In form this species resembles some species of Hoorthis remnicha (Winchell)

(Pls. XCI, XCII), but in surface characters it is quite unlike any of them.

184 CAMBRIAN BRACHIOPODA.

The specific name is given in honor of Dr. J. S. Newberry.

FORMATION AND LOCALITY.—Upper Cambrian: (54c) About 1,100 feet (885.3 m.) above the Middle Cambrian and
120 feet (36.6 m.) below the top of the Upper Cambrian in the central part of the limestones forming 1 of the St. Charles
formation | Walcott, 1908f, p. 192]; and (54d) about 1,050 feet (320 m.) above the Middle Cambrian and 175 feet (53.3 m.)
below the top of the Upper Cambrian, in the lower part of the limestones forming 1 of the St. Charles formation [Wal-
cott, 1908f, p. 192]; both in Blacksmith Fork Canyon, about 10 miles (16.1 km.) east of Hyrum, Cache County, Utah.

HoorTHIS NEWTONENSIS (Weller).

Plate XOVILI, figures 9, 9a.

' Orthis newtonensis WELLER, 1903, Geol. Survey New Jersey, Rept. Paleontology, vol. 3, pp. 113-114, Pl. I, figs. 3-5.

(Described and discussed as a new species. )

Orthis (Plectorthis) newtonensis (Weller), WaLcorr, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 267. (Described and dis-
cussed as below.)

This little shell occurs in the form of casts in a sandstone that is too coarse to preserve
the details of the outer surface. The cast of the interior shows fine, simple, radiating ribs
that increase by interpolation and that are coarser on the ventral than on the dorsal valve.
Ventral valve slightly flattened at the front; dorsal valve with a broad mesial sinus. The
shell appears to have been thin. The cast of the pseudospondylium of the ventral valve
shows it to have been clearly defined; the area is low and not sharply defined from the curve
of the cardinal margin; it is nearly vertical to the plane of the margin of the valve. The cast
of the area beneath the umbo in the dorsal valve is more triangular and less transverse than
usual; unfortunately the material is too imperfect to determine any details.

Observations.—This species is the eastern representative in the Upper Cambrian of Hoorthis
indianola (Walcott) and EH. iddings, (Walcott). As far as can be determined by the material
available for comparison it is closely related to those species but it is not probable that they
are specifically identical.

The specific name is derived from Newton, New Jersey.

FoRMATION AND LOCALITY.—Upper Cambrian: (11c) Hardyston quartzite [Weller, 1900, pp. 10 and 12], O’Don- ©
nell and McManniman’s quarry, Newton, Sussex County, New Jersey.

EoortTuis PAGODA (Walcott).
Plate XCVII, figures 12, 12a—d.

Orthis (Plectorthis) pagoda Watcott, 1905, Proc. U. S. Nat. Mus., vol. 28, pp. 267-268. (Described and discussed as
below as a new species.)

Shell transverse, subsemicircular; a ventral valve 11 mm. in length has a width of 15 mm.,
and a dorsal valve 8 mm. in length has a width of 13 mm.; hinge line a little shorter than the
greatest width of the shell; cardinal angles vary from 75° to 111°; valves moderately convex.
Cardinal area narrow in both valves and inclined backward from the hinge line. Surface marked
by equidistant, narrow, low ribs, 3 in a space of 2 mm. near the front margin of a shell 10 mm.
long, with fine, radiating strie between them; the radiating ribs and striz are crossed by
fine, concentric striz, and lines of growth.

Ventral valve with a strong, somewhat angular, median fold rismg from a well-defined
depression on each side of it, or it might be designated as a very strong rib rising above the
general surface of the valve from a broad, median depression; the lateral slopes are gently
convex. Dorsal valve with a strong, angular, median depression, beginning at the posterior
margin and gradually widening to the front; the sides of the depression rise above the general
surface of the valve, and form with the outer slope a well-defined low ridge on each side that
extends a little forward on the front margin to fit to the depressions on each side of the
median fold of the ventral valve.

The interior of a small dorsal valve has a broad, strong ridge corresponding to the depres-
sion on the exterior surface; a main vascular sinus starts on each side of the base of the median
ridge and arches outward and then forward about a depressed oval space on each side of the

BILLINGSELLID A. 785

ridge; lateral branches extend from the main sinus toward the sides; the impressions of the
anterior and posterior adductor muscle scars occur on the slopes of the median ridge and the
oval depressions; somewhat obscure radiating lines mark the anterior portions of the surface.
Observations ——This shell is distinguished by its strongly marked median ridge on the
ventral valve and sinus on the dorsal valve. In general form and surface markings it is not
unlike Hoorthis desmopleura (Meek) and LH. wichitaensis (Walcott).
The specific name is derived from Pagoda Hill, the type locality.

. FORMATION AND LOCALITY.—Upper Cambrian: (C56) Lower part of Chaumitien limestone, at Pagoda Hill [Black-
welder, 1907a, p. 42 (part of last list of fossils)], 1 mile (1.6 km.) west of Tsinan; and (C54) lower part of the
Chaumitien limestone [Blackwelder, 1907a, p. 42 (part of last list of fossils)], 0.66 mile (1.1 km.) west of Tsinan;
both in Shantung, China.

Hoorruis PAPras (Walcott).

’ Plate XCI, figure 4.

Orthis (Plectorthis) papias Waucotr, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 268. (Characterized as below as a new
species. )

This species is founded to receive a form represented by two small dorsal valves from the
Paradowides zone of Newfoundland. They are moderately convex, with a low area divided by
a broad delthyrium; surface marked by numerous, rounded, depressed ribs, crossed by con-
centric striz and ridges of growth. Length of shell, 4 mm.; width, 5 mm.

FORMATION AND LOCALITY.—Middle Cambrian: (61) Shales near the top of No. 6 of the Manuels Brook section
“[Walcott, 1891b, p. 261], east side of Manuels Brook, Conception Bay, Newfoundland.

EOoORTHIS PRIMORDIALIS (de Verneuil and Barrande).

Plate XCVII, figures 1, la-d.

Orthis primordialis DE VERNEUIL and BARRANDE, 1860, Bull. Soc. géol. France, 2d ser., vol. 17, pp. 532-533, PI.
VIII, figs. 6, 6a-d. (Described and discussed in French, as a new species; see below for translation. Figs. 6,
6a-d are reproduced in this monograph, Pl. XCVII, figs. 1, la—d, respectively.)

Orthis primordialis de Verneuil and Barrande, MauzapA, 1875, Bol. Com. Mapa Geoldgico Espaia, tome 2, p. 31. (Men-
tioned in Spanish.) ;

The original description by de Verneuil and Barrande follows:

Shell transverse, rounded on the sides, wider than long. Hinge ridge does not extend to lateral extremities and
measures hardly more than three-fourths of the total breadth of theshell. The two valves are of about the same thick-
ness. The ventral valve is provided withan area hardly higher than that of the opposite valve, but it is distinguished
from it by a sinus which is almost as deep as that of the Spirifers, and which in front forms a very pronounced and
more or less sharp fold. Surface ornamented with striz, very dichotomous on the sides and almost simple in the sinus;
at a distance of 5 mm. from the beak, 7 striz are counted in a space of 5 mm.

Breadth, 16 mm.; length, 12 mm.; thickness, 7 mm.

By its deep sinus, this species is distinguished from most of its congeners and establishes a sort of passage between
the genera Orthis and Spirifer; however, the pronounced area observed on each of the two valves is a characteristic
which links it with the former rather than with the latter genus. Orthis species provided with sinuses are rather rare;
the principal ones are O. sinuata Hall and O. striatula Schl., which for that matter have no other analogy with our
species. It might perhaps be assimilated to O. lynx, which also has two areas equally developed, but the latter species
will always be recognized by the small number and nondichotomous nature of its folds.

Observations.—This shell is more strongly developed in the sinus of the ventral valve and
the fold of the dorsal valve than any other species of Cambrian Hoorthis, with the possible excep-
tion of H. ndianola (Walcott) of the Middle and Upper Cambrian of the Wichita Mountains of the
United States. The latter has a higher area on the ventral valve and the sinus is often shallow,
while the fold is usually absent.

FORMATION AND LOCALITY.—Middle Cambrian: (350 [de Verneuil and Barrande, 1860, p. 538]) Red limestone of

the Paradoxides zone, near Adrados, north of Sabero and Bofar, Cantabrian Mountains, Province of Leon, north-
western Spain.

@ Following here the example of Owen and Davidson, we call ventral valve the larger of the two, the one which is provided with a large area,
and which formerly was called dorsal valve.

62667°—vo1 51, pr 1—12——50 a

786 CAMBRIAN BRACHIOPODA.

Eoortuis reMNicHA (N. H. Winchell).
Text figure 7, page 299; Plate XCI, figures 1, la-s; Plate XCII, figures 2, 2a-d, 3, 3a-e.

Orthis remnicha N. H. WincHELL, 1886, Fourteenth Ann. Rept. Geol. and Nat. Hist. Survey Minnesota, pp. 317-318,

i Pl. II, fig. 7. (Described and discussed as a new species.)

Orthis? remnicha Winchell, Watcorr (in part), 1899, Mon. U. S. Geol. Survey, vol. 32, pt. 2, pp. 451-452, Pl. LXTI,
figs. 3 and 3a; Pl. LXII, figs. 1, 1e-d (mot figs. la and 1b). (Described and discussed essentially as below. The
specimens represented by Pl. LXI, figs. 3 and 3a, and Pl. LXII, figs. 1, le, and 1d, are redrawn in this mono-
graph, Pl. XCII, figs. 2b, 2a, 2, 2d, and 2c, respectively. The specimens represented by Pl. LXII, figs. la and -
1b, are now referred to Hoorthis iddingsi.)

Orthis (Plectorthis) remnicha (Winchell), Waxucorr, 1905, Proc. U. S. Nat. Mus., vol. 28, pp. 268-269. (Described and
discussed essentially as below.)

Plectorthis remnicha (Winchell), GRaBav and Sauer, 1907, North American Index Fossils, vol. 1, p. 252. (Described.)
Shell of medium size, usually slightly transverse, with an oblong, oval outline for the

ventral valve, and a subquadrate to semicircular outline for the dorsal valve. Valves moder-
ately convex, with an almost straight hinge line that varies in length from nearly the greatest
width of the shell to two-thirds the greatest width; cardinal angles varying from 90° or less in
the extreme forms, with extremities somewhat angular, to the other extreme, where they are
very obtuse and have the appearance of being almost rounded, their angle bemg not less than
120°. Cardinal area narrow but well developed on each valve, and divided by a rather large
delthyrium.

The ventral valve has in some specimens a shallow mesial depression, and in some examples
it is flattened toward the cardinal angles; beak small and curving down toward the hinge line,
beyond which it projects slightly. Dorsal valve slightly less convex than the ventral; beak
small, scarcely projecting beyond the hinge line.

Surface marked by bifurcating, radiating cost, that vary in number on shells of similar
size from 16 in the space of 5 mm. to 3 in the same space; this variation is shown in the speci-
mens from Texas, Wisconsin, and Wyoming. As the shell grew the ribs increased in number by
interpolation and by bifurcation from the sides of the larger ribs. In well-preserved specimens
very fine, radiating, raised strie occur both on the coste and on the intervening depressions .
(Pl. XCII, fig. 2c). These are shown on the casts of the shells from the ‘‘St. Croix sandstone
of Winfield, Wisconsin, and on the larger shells from the limestones of Oklahoma and the
Yellowstone National Park. A very perfectly preserved fragment of the outer shell covering
the umbo and apex of a ventral valve from the limestone of the Reagan sandstone, Oklahoma,
has sharp ribs of varying size extending to the worn apex; the ribs are crossed by very fine,
threadlike strize and a few stronger lines of growth.

The interior of the ventral valve shows a slightly raised tripartite pseudospondylium
beneath the umbo, which is the only trace of interior markings of this valve observed. The
interior of the dorsal valve has a slightly elevated area upon which occurs a narrow, short
median septum; the crural plates are also well shown. In casts of the interior of shells from
the ‘‘St. Croix sandstone” of Wisconsin, the dental lamellae of the ventral valve are finely
shown, and in the dorsal valve the median septum and crural plates.

Observations.—The shell is one of the most variable that occurs in the Cambrian fauna.
Its range of variation in all of the widely separated localities in which it occurs is such that one
would scarcely hesitate, if in possession only of the extremes, to identify two well-marked species.
The variation is not only in the radiating costz, but also in the general form of the shell. This
variation is expressed in three varieties that receive names, and others might be designated if
more minute variations were given consideration.

There does not appear to be any system governing the number or size of the radiating ribs;
the variation on adult shells is equally great with that between young shells 3 to 4 mm. long
and adults. A series from Winfield, Wisconsin, representing Hoorthis remnicha winfieldensis,
is uniform in radial ribs and form from young shells 3 mm. long to the largest adults 23 mm.
long, and there are also shells that serve to unite the numerously and uniformly ribbed speci-
mens with the more variable Hoorthis remmicha.

BILLINGSELLIDA. 787

Some of the shells referred to H. remmacha (Pl. XCI, figs. 1, 1a, and le) suggest Platystrophia
in their form and radiating ribs.

FORMATION AND LOCALITY.—Upper Cambrian: (80a) ‘“‘St. Croix sandstone,’’ 4 miles (6.4 km.) north of Reedsburg,
Sauk County; (328q) ‘St. Croix sandstone” in quarry at Ableman, Sauk County; and (97a) ‘‘St. Croix sandstone,”’
near Winfield, Jefferson County; all in Wisconsin.

(86a) “‘St. Croix sandstone,” near Red Wing, Goodhue County, Minnesota.o

(158a and 154) Limestone on west side of Dry Creek, near the mouth of Pass Creek, about 5 miles (8 km.) north of
Hillsdale, Threeforks quadrangle (U. 8. Geol. Survey), Gallatin County; (302n) limestone on the south side of the
Gallatin Valley, Gallatin County; and (4r) just above the Middle Cambrian in the limestones of the Gallatin formation of
Peale [1893, Pl. IV], on ridge 8 miles (12.8 km.) east of Yellowstone River, and 3 miles (4.8 km.) north-northeast of

“Mount Delano, Livingston quadrangle (U. S. Geol. Survey), Park County; both in Montana.

(168) Limestone on north side of Tepee Creek, beside the road from Sheridan to Dome Lake, Bighorn Mountains,
Sheridan County, Wyoming.

(12k) Limestones of the Reagan sandstone (in the section 7 miles (11.2 km.) north of Springer this horizon is
about 225 feet (69 m.) above the porphyry contact and 55 feet (17 m.) below the Arbuckle limestone) on the west side
of Honey Creek, near the southeast corner of sec. 35, T. 1 S., R. 1 E., Ardmore quadrangle (U. S. Geol. Survey),
Carter County; (12n) limestones of the Reagan sandstone (in the section 7 miles (11.2 km.) north of Springer this
horizon is about 240 feet (73 m.) above the porphyry contact and 40 feet (12 m.) below the Arbuckle limestone),
NW. tsec.1, T.28., R. 1 E., Ardmore quadrangle (U.S. Geol. Survey), Carter County; and (12p) about 225 feet (69 m.)
above the igneous rocks in the limestones of the Reagan sandstone, at the northwest extremity of the Arbuckle Moun-
tains, about 4 miles (6.4 km.) east of Homer, Carter County; all in Oklahoma.

Middle Cambrian: (302b) Limestone near Crowfoot Ridge, Gallatin quadrangle (U.S. Geol. Survey), Yellowstone
National Park, Wyoming.

Specimens that are somewhat doubtfully referred to this species occur at the following
locality:

Middle Cambrian: (8x) About 2,200 feet (670.6 m.) above the Lower Cambrian and 2,200 feet (670.6 m.) below the
Upper Cambrian in the limestone forming 1d of the Marjum limestone [Walcott, 1908f, p. 180], 2.5 miles (4 km.) east

of Antelope Springs, in ridge east of Wheeler Amphitheater [Walcott, 1908f, Pls. XIII and XV], House Range,
Millard County, Utah.

HOoORTHIS REMNICHA SULCATA (Walcott).
Plate XCII, figures 1, la-c.

Orthis (Plectorthis) remnicha sulcata Watcott, 1905, Proc. U.S. Nat. Mus., vol. 28, p. 269. (Characterized somewhat
as below as a new variety.)

This variety is founded on the strongly suleate dorsal valve. The ventral valve shows
only a slight flattenmg of the median portion. Finkelnburgia osceola (Pl. XCIII) has a mesial
fold on the dorsal valve, but it is not so sharp.

FORMATION AND LOCALITY.—Upper Cambrian: (80a) ‘St. Croix sandstone,’ 4 miles (6.4 km.) north of Reedsburg,
Sauk County; and (97a) “‘St. Croix sandstone” near Winfield, Jefferson County; both in Wisconsin.

(389d) “‘St. Croix sandstone” at Taylors Falls, Chisago County; and (97x) ““St. Croix sandstone” at Reads Landing,
foot of Lake Pepin, Wabasha County; both in Minnesota.

HoortTHIs REMNICHA TEXANA (Walcott).
Plate XCII, figures 4, 4a-g.

Orthis (Plectorthis) remnicha tecana Watcorr, 1905, Proc. U.S. Nat. Mus., vol. 28, p. 270. (Characterized as below as

a new variety.)

The rounded, subquadrate form and the arrangement of the radiating cost serve to
differentiate this variety. The coste vary considerably on different shells, but the tendency
of the larger number is toward the surface represented by Plate XCII, figures 4c-g. Fine
radiating striz, similar to those represented by Plate XCII, figure 2c, of Hoorthis remnicha
occur on the ribs and interspaces.

FORMATION AND LOCALITY.—Upper Cambrian: (12m) Arbuckle limestone (in the section 7 miles (11.2 km.) north

of Springer this horizon is about 30 feet (9.1 m.) above the Reagan sandstone), NE. 4 sec. 2, T.2 S., R.1 E.; and (12n)
limestones of the Reagan sandstone (in the section 7 miles (11.2 km.) north of Springer this horizon is about 240 feet

aN. H. Winchell [1886, p. 317] gives the type locality as ‘‘St. Croix sandstone’’ in sewer excavation at the corner of Brush and Main
Streets, Red Wing, Minnesota.

788 CAMBRIAN BRACHIOPODA.

(73 m.) above the porphyry contact and 40 feet (12 m.) below the Arbuckle limestone), NW. ¢ sec. 1, T.2S., R.1 E.;
both in the Ardmore quadrangle (U. S. Geol. Survey), Carter County, Oklahoma.

(153a) Limestone in ravine on west side of Dry Creek, near the mouth of Pass Creek, about 5 miles (8.1 km.) north
of Hillsdale, Threeforks quadrangle (U. 8. Geol. Survey), Gallatin County, Montana.

(14b) Limestone on Cold Creek at north end of gorge opposite the north end of Sponge Mountain, 2 miles (3.2km.)
south of the San Saba County line, in Llano County; (68) interbedded sandstone and limestone, Packsaddle Mountain,
Llano County; and (71) limestone in Cold Creek Canyon, Burnet County; all in Texas.

Specimens that are somewhat doubtfully referred to this variety occur at the following
localities:

Upper Cambrian: (11d) Arenaceous limestone about 2 miles (3.2 km.) north of Montana, in sec. 22, T. 35 N., RB. I 1B.
Tron County; and (111) arenaceous limestone of the Elvins formation, 50 feet (15.2 m.) above the ‘‘Edgewise beds,”’ St.
Francois County; both in Missouri.

EOORTHIS REMNICHA WINFIELDENSIS (Walcott).
Plate XCI, figures 2, 2a-e.
Orthis (Plectorthis) remnicha winfieldensis Waxcott, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 270. (Characterized as
below as a new variety.)

This variety is characterized by having finer and more uniform cost than any of the shells
referred to Eoorthis remnicha (N. H. Winchell). The costz increase by interpolation rather than
bifurcation in the true sense of the word. The shorter costz begin as very narrow, sharp
ridges, merging into the sides of the larger costes below the summit of the latter, or they may
arise entirely on the interspaces between the coste. The pseudospondylum is less strongly
developed than in E. remnicha. The young shells are usually narrower at the hinge line than
the adult; but this feature is sometimes present in large shells (Pl. XCI, fig. 2c).

The varietal name is derived from Winfield, Wisconsin.

ForMATION AND LOCALITY.—Upper Cambrian: (97a) ‘‘St. Croix sandstone,’ near Winfield, Jefferson County; and
(99a) ‘‘St. Croix sandstone” near Pilot Knob, Adams County; both in Wisconsin.

A specimen which is somewhat doubtfully referred to this variety occurs in the following
locality : ;

Upper Cambrian: (83) ‘‘St. Croix sandstone” at Trempealeau, Trempealeau County, Wisconsin.

EoorrHis SALTENSIS (Kayser).
Plate XCVII, figure 11. -

Orthis saltensis KaysEr, 1876, Beitrige zur Geologie und Paleontologie der argentinischen Republik, vol. 2, Pale-
ontologischen Theil; Abth. 1, p. 8, Pl. I, figs. 15,16. (Described and discussed in German as a new species; see
below for translation. Figs. 15 and 16 are reproduced in this monograph, Pl. XCVII, figs. 11’ and 11, respec-
tively.)

Orthis saltensis? Kayser, 1897, Zeitschr. Deutsch. geol. Gesell. for 1897, Bd. 49, Heft 2, No. 2, p. 280. (Mentioned in
German from new localities. )

Orthis (Plectorthis) saltensis (Kayser), Watcort, 1905, Proc: U. S. Nat. Mus., vol. 28, p. 271. (Characterized. )

The original description by Kayser follows:

Shell nearly circular in outline, with straight hinge edge, which is about equal to three-fourths of the greatest
breadth of the shell, measured approximately across the middle. Ventral valve moderately and uniformly arched,
with a faint keel rising in the middle. Beak short, slightly curved. Dorsal valve slightly arched, with a median
depression which is flat but becomes rather broad, starting at the umbo. The surface of both valves is covered with
fine but plainly marked ribs, united into bundles, the lateral ones bending somewhat outward.

In the sandstones in the province of Salta this species fills whole beds. At the town of Salta it occurs alone. At
the Nevado de Castillo it is accompanied by Lingula. At both localities it occurs as impressions and casts, and as
white, well-preserved shell, peeling off in flakes. Finally it also occurs, associated with trilobites, Hyolithes, and
other Orthis species, at Tilcuya in the province of Jujuy, but there it is without calcareous shell. I know only one
primordial Orthis with which this fine species might be compared, namely Orthis menapizx Hicks [cf. Davidson, 1869,
Pl. XXXIII, figs. 8-12], from the English Arenig group. In this, however, the ribs show less.tendency to arrange
themselves in bundles, the sinus is narrower, and the ventral valve is much more strongly keeled.

Kayser’s description and figures [1876, p. 8, Pl. I, figs. 15-16] lead me to refer this species
to the genus Hoorthis. The general form of the valves, the casts of the interior of the ventral

|

BILLINGSELLID. 789

valve with the strong umbonal cavity, and the radiating ribs increasing in number by inter-
polation, appear to sustain the reference.
The species derives its name from its occurrence near Salta.

FORMATION AND LOCALITY.—Upper Cambrian: (389 [Kayser, 1876, p. 8]) Sandstone at Salta, Province of Salta; (389a
[Kayser, 1876, p. 8]) sandstone at Nevado de Castillo, Province of Salta; (389d [Kayser, 1897, p. 280]) at Iruya,
Province of Salta; (889c [Kayser, 1897, p. 280]) in conglomeratic sandstone at Ojo de Agua, Province of Santiago del
Est; and (389b [ Kayser, 1876, p. 8]) sandstone at Tilcuya, Province of Jujuy; all in Argentina, South America.

Kayser [1876, p. 9, Pl. I, fig. 13] also describes and illustrates the dorsal valve of a shell
that he refers to Orthis sp. It suggests Orusia lenticularis.

Koortuts TATEI (Htheridge).
Plate XOVII, figures 15 and 15a.

Orthis (?)tate. ETHERIDGE, gR., 1905, Trans. Roy. Soc. South Australia, vol. 29, p. 249, Pl. XXV, figs. 7 and 8.
(Described as below, and discussed as a new species. The specimens represented by figs. 7 and 8 are redrawn
in this monograph, Pl. XCVII, figs. 15 and 15a, respectively. )

The original description by Etheridge follows:

Pedicle valve, dorsal margin comparatively straight; ventral and lateral margins rounded, the former nonmar-
ginate; umbo small, depressed; surface in the median line moderately convex, the wings rather flattened; sculpture
consisting of numerous, thick, sometimes bifurcating radiating coste, which die out, or are only faintly perceptible
on the wings or toward the lateral margins of the valves, the surface on these portions being also crossed by very fine
concentric lines; by the prominence of two or three coste on each side of the middle, a flattened space, taking the
place of a sulcus, is marked off.

This species appears to belong to the group of Hoorthis represented by E. remnicha (N. H.
Winchell).
The specific name is given in honor of Mr. Ralph Tate.

FORMATION AND LOCALITY.—Middle? Cambrian: (315b [Etheridge, 1905, p. 249]) Limestone at Wirrialpa,
Flinders Range, South Australia.

EoortHis THYONE Walcott.
y Text figures 70A-C.

Nisusia rara Watcort (in part), 1908, Smithsonian Mise. Coll., vol. 53, No. 3, p. 97, Pl. IX, fig. 13 (not fig. 13a, which
represents a specimen of Misusia rara). (No text reference. Fig. 13, which is reproduced in this monograph
as fig. 70A, was inserted on Pl. IX :
of this reference by mistake. All
of the figures representing the two
species (Misusia rara and Hoorthis
thyone) happened to be grouped on
the same preliminary plate and
when two figures were chosen to
represent Nisusia rara in the paper
referred to, one of the figures repre- FIGURE 70.—Zoorthis thyone Walcott. A, Natural cast of a ventral valve, the type speci-
senting Eoorthis thyone was acci- men, showing cast of a pseudospondylium (U.S. Nat. Mus. Cat. No. 52378). B, Natural

. cast of a dorsal valve (U. S. Nat. Mus. Cat. No. 52377a). C, Cast of interior of dorsal
dentally included.) valve (U. S. Nat. Mus. Cat. No. 52377b).
Eoorthis thyone Waucorr, 1908, idem, pp. The specimens represented are from Middle Cambrian Marjum limestone, 2.5 miles (4
105-106, Pl. X, figs. 7 and 7a. (De- km.) east of Antelope Springs, in the ridge east of Wheeler Amphitheater, House Range,
9 : a Millard County, Utah (fig. 704 from Locality 8x, and figs. 70B and 70C from Locality 11q).
scribed and discussed as below as a Figure 70A was published [Walcott, 1908d, Pl. IX, fig. 13] as representing the ventral valve
new species. Figs. 7 and 7a are of Nisusia rara and was given Cat. No. 52295a. As explained in the note under the
copied in this monograph as figs. first reference in the synonymy this was a mistake. Figures 70B and 70C are copied
3 7. :
70B and 70G, respectively.) from Walcott [1908d, Pl. X, figs. 7 and 7a, respectively].

In outline and size this species resembles Hoorthis wichitaensis (Walcott) (Pl. XCIV, figs.
1, la-n), but in its sharp, uniform, radiating ribs it differs from that and other species having
a somewhat similar outline. The ribs radiate from the beak and increase in number by inter-
polation of new ribs at irregular distances from the beak. Nothing is known of the area of
either valve. A cast of the interior of a dorsal valve shows rather large muscle scars.

A large ventral valve has a length of 8 mm.; width, 9 mm.; substance of shell unknown.

790 CAMBRIAN BRACHIOPODA.

Observations.—This species was at first compared with Nisusia (Jamesella) nautes (Walcott)
(Pl. XCIII, figs. 6, 6a-b), but the surface ribs are more regular and less numerous. It also
occurs 1,800 feet higher in the stratigraphic section than JV. (J.) nautes.

ForMATION AND LOCALITY.—Middle Cambrian: (3x) About 2,200 feet (670.6 m.) above the Lower Cambrian and
2,200 feet (670.6 m.) below the Upper Cambrian, in the limestones forming 1d of the Marjwm limestone | Walcott, 1908f,
p. 180]; and (11g) about 2,350 feet (716.3 m.) above the Lower Cambrian, and 2,050 feet (624.8 m.) below the Upper
Cambrian, in the limestones forming le of the Marjum limestone [Walcott, 1908f, p. 180]; both 2.5 miles (4 km.) east
of Antelope Springs, in ridge east of Wheeler Amphitheater [Walcott, 1908i, Pls. XIII and XV], House Range, Millard
County, Utah. ;

E0oRTHIS TULLBERGI (Walcott).

Plate XCV, figure 3.

Orthis (Plectorthis) tullbergi Waucorr, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 271. (Characterized as a new species.)

Orthis (Plectorthis) tullbergi Walcott, Moprre and SncERBeERG, 1906, Medd. fran Lunds Geol. Faltklubb, Ser. B,
No. 2 (Aftryck ur K. Fysiografiska Sallskapets Handl., N. F., Bd. 17), p. 69, Pl. II, fig. 3. (Characterized
in Swedish. Fig. 3, in common with the remaining figures on Pl. II of Moberg and Segerberg’s paper, was
copied from a preliminary photograph of Pl. XCV of this monograph.)

The transverse outline and simple strong ribs of Hoorthis tullbergi serve to distinguish it
from £. christianie (Kjerulf) and E. daunus (Walcott).

Moberg and Segerberg [1906, pp. 69-70] are inclined to consider this form as identical _

with Eoorthis christianie. Since reading their remarks and conclusions I have studied the
material representing the two forms Hoorthis christianiz and FE. tullberg, and have decided
to leave the latter as a distinct species. There may be a complete gradation of form and surface
characters between the two shells, but I do not find it in the numerous specimens before me.
The specific name was given in honor of Mr. 8S. A. Tullberg.
FORMATION AND LOCALITY.—Passage beds between the Upper Cambrian and the Ordovician: (390) Boundary

stratum between the Orthoceras limestone and the Ceratopyge limestone [Moberg and Segerberg, 1906, p. 69], at
Alunbruk (alum works), southern part of Oeland Island, Sweden.

EoorTHIS WICHITAENSIS (Walcott).

Plate XCIV, figures 1, la-o, 1u.

Orthis (Plectorthis) wichitaensis Waxcorr, 1905, Proc. U. 8. Nat. Mus., vol. 28, pp. 271-272. (Characterized essen-
tially as below as a new species.)

In general form and outline this shell is related to Hoorthis desmopleura (Meek) and
E. remnicha (Winchell). Its convexity and differences in the radial ribbing and striation sep-
arate it from the former species, and it occurs in an older geological formation. Its convexity
and surface characters distinguish it from EH. remnicha. The series of figures illustrating the
species will enable the student to study all that is known to me of the species.

A considerable number of relatively smooth shells that occur in the collection are desig-
nated as the variety leviwsculus, but it is often difficult to separate them from the more finely
ribbed specimens that are typical of the species.

FoRMATION AND LOCALITY.—Lower Ordovician: (360a) Red siliceous limestone on west side of Trout Creek,
below Bergen Park, 7 miles (11.2 km.) north-northwest of Manitou, El Paso County, Colorado.

Upper Cambrian: (12j) Lower part of Arbuckle limestone at Small Hill, 2 miles (3.2 km.) southwest of Signal
Mountain, about 8 miles (12.8 km.) west of Fort Sill; and (9z) basal beds of the Arbuckle limestone, about 25 feet above
the heavy-bedded limestone, near the middle of the west half of see. 13, T. 4 N., R. 13 W., about 13 miles (20.8 km.)
northwest of Fort Sill; both in Comanche County, Oklahoma.

(9q) About 10 feet (3 m.) above the porphyry contact and 90 feet (27.4 m.) below the Arbuckle limestone in
limestones of the Reagan sandstone, in middle of west half of sec. 2, T. 4 N., R. 13 W.; (9u) about 195 feet
(59.4 m.) above the porphyry contact in the limestones of the Reagan sandstone, in SE. NH. 4 sec. 2, T. 4 N.,
R. 18 W.; (9s) about 85 feet (26 m.) below the Arbuckle limestone in the limestones of the Reagan sandstone, near
middle of west half of sec. 13, T. 4 N., R. 13 W.; all about 15 miles (24.2 km.) northwest of Fort Sill, Comanche County,
Oklahoma.

(12k) Limestones of the Reagan sandstone (in the section 7 miles (11.2 km.) north of Springer this horizon is
about 225 feet (69 m.) above the porphyry contact and 55 feet (17 m.) below the Arbuckle limestone), on the west

BILLINGSELLIDA. 791

side of Honey Creek, near the southeast corner of sec. 35, T. 1 S., R. 1 E:, Ardmore quadrangle (U. S. Geol. Survey),
Carter County; (12n) limestones of the Reagan sandstone (in the section 7 miles (11.2 km.) north of Springer this
horizon is about 240 feet (73 m.) above the porphyry contact and 40 feet (12 m.) below the Arbuckle limestone), NW.
¢sec. 1, T.28., R. 1 E., Ardmore quadrangle (U. 8. Geol. Survey), Carter County; and (12p) about 225 feet (69 m.)
above the igneous rocks in the limestones of the Reagan sandstone, at the northwest extremity of the Arbuckle Mountains,
about 4 miles (6.4 km.) east of Homer, Carter Cownty; all in Oklahoma.

(14b) Limestone on Cold Creek at north end of gorge opposite the north end of Sponge Mountain, 2 miles (3.2
km.) south of the San Saba County line, in Llano County; (68) limestone on Packsaddle Mountain, Llano County;
and (71) limestone in Cold Creek Canyon, Burnet County; all in Texas.

(150a) Limestone on the east side of Dry Creek, above the mouth of Pass Creek; and (158a) limestone in ravine
on west side of Dry Creek, near the mouth of Pass Creek; both about 5 miles (§ km.) north of Hillsdale, Threeforks
quadrangle (U. 8. Geol. Survey), Gallatin County, Montana.

(151) Limestone in point overlooking Churn Canyon, on the west side of the Bridger Range, Gallatin County,
Montana. q

(302e) Limestone near the top of the Deadwood formation, in Middle Popo Agie Canyon, near Lander, Fremont
County, Wyoming.

Middle Cambrian: (369a) Limestone in or just beneath the ‘‘Edgewise beds” near Elvins, 6 miles (9.6 km.)
south of Bonneterre, St. Francois County, Missouri.

EooRTHIS WICHITAENSIS L&vruscuLuS (Walcott).

Plate XOIV, figures 1p-s.

Orthis (Plectorthis) wichitaensis leviusculus Waxcorr, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 272. (Characterized
essentially as below as a new variety.)

A variety with small, narrow, numerous ribs is given the above name. So many grada-
tions exist between it and the typical forms of LH. wichitaensis (Walcott) that the figures are
arranged on the plate rather to show the gradations in surface characters than to bring out
this special variety.

FoRMATION AND LOCALITY.—Upper Cambrian: (12k) Limestones of the Reagan sandstone (in the section 7
miles (11.2 km.) north of Springer this horizon is about 225 feet (69 m.) above the porphyry contact and 55 feet (17 m.)
below the Arbuckle limestone), on the west side of Honey Creek, near the southeast corner of sec. 35, T.1S., R.1E.,
Ardmore quadrangle (U. S. Geol. Survey), Carter County; (12n) limestones of the Reagan sandstone (in the section
7 miles (11.2 km.) north of Springer this horizon is about 240 feet (73 m.) above the porphyry contact and 40 feet
(12 m.) below the Arbuckle limestone), NW. } sec. 1, T. 2S., R. 1 E., Ardmore quadrangle (U. S. Geol. Survey),
Carter County; and (12p) about 225 feet (69 m.) above the igneous rocks in the limestones of the Reagan sandstone, at the
northwest extremity of the Arbuckle Mountains, about 4 miles (6.4 km.) east of Homer, Carter County; all in Oklahoma.

(14b) Limestone at north end of gorge opposite the north end of Sponge Mountain, 2 miles (3.2 km.) south of
the San Saba County line; and (68) limestone in Packsaddle Mountain; both in Llano County, Texas.

EoorrTHis wimmant (Walcott).

Plate XCV, figures 4, 4a-d.

Orthis (Plectorthis) wimani Waucott, 1905, Proc. U. 8. Nat. Mus., vol. 28, p. 272. (Discussed essentially as below as a
new species.)

Orthis (Plectorthis) wimani Walcott, Mopere and SrcerBere, 1906, Medd. fran Lunds geol. Faltklubb, Ser. B, No. 2
(Aftryck ur K. Fysiografiska Sillskapets Handl., N. F., Bd. 17), p. 70, Pl. II, figs. 4, 4a-d; Pl. III, figs. 14,
15a-b. (Discussed in Swedish. Figs. 4, 4a-d, in common with the remaining figures on Pl. II of Moberg and
Segerberg’s paper, were copied from a preliminary photograph of Pl. XCV of this monograph.)

This shell is distinguished from Hoorthis christame (Kjerulf) and EL. dawnus (Walcott) by
the rounded, narrow, simple ribs and the less transverse and more rounded outline. A ventral
valve discovered after the drawings were made shows a well-defined pseudospondylium, with
the tripartite division as seen in F. remnicha (Winchell) (Pl. XCI, fig. 1c). Two strong main
vascular sinuses extend forward from the lateral divisions of the umbonal cavity nearly to
the front of the valve, corresponding in position to those of the dorsal valve (Pl. XCV, fig.
4a). The cast of the dorsal valve indicates the presence of rather strong crura, crural plates,
dental sockets, and delthyrium.

The ventral valve is rather strongly convex, and the dorsal valve about half as much so.
The average size is 6 to 7 mm. in diameter, the ventral valve being about 1.5 mm. larger

792 ~ CAMBRIAN BRACHIOPODA.

than the dorsal. The largest ventral valve in the material available for study has a length
of 9 mm.
The specific name was given in honor of Dr. Carl Wiman.

FORMATION AND LOCALITY.—Passage beds between the Upper Cambrian and the Ordovician: (810j) Ceratopyge
limestone at Borgholm, Oeland Island, Sweden.

(8x) Limestone at Slemmestad, about 3 miles (4.8 km.) southwest of Christiania, Norway.

Upper Cambrian: (390b [Moberg and Segerberg, 1906, p. 71]) Limestones of the Shwmardia zone (zone 3) at Fogel-
sang, 5 miles (8 km.) east of Lund, Province of Malméhus; and (390c[Moberg and Segerberg, 1906, p. 70]) Ceratopyge
slate (Zone 3) at Wentlinge, on Oeland Island; both in Sweden.

(323w) Black argillaceous shale of Division 3aB, at Christiania, Norway. .

| Eoorruts zENo Walcott.
' Text figures 71A—B’.

Eoorthis zeno Watcott, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, p. 106, Pl. 10, fig. 8. (Discussed as below as a

new species. Fig. 8 is copied in this monograph as fig. 714.)

In outline the ventral valve of this species is somewhat similar to that of some forms of
Eoorthis remnicha winfieldensis (Walcott) (Pl. XCI, fig. 2d), but it differs in having finer radiating
ribs and in its smaller size.
It is also much smaller
than LHoorthis newberryi
Walcott, and it occurs
4,390 feet (1,338 m.) lower
in the same stratigraphic
section. The character of
the surface is shown by
text figure 71B’, and the

FIGURE 71.—Eoorthis zeno Walcott. A, A’, Exfoliated ventral valve (U.S. Nat. Mus. Cat. No. 52397a). general form -by text fig-
B, Fragment of dorsal valve (U. S. Nat. Mus. Cat. No. 52397b). B’, Enlargement of portionof wre 71A. [do not know
surface of B (X 10). ;

The specimens represented are from Locality 540, Middle Cambrian Ute limestone in Blacksmith of any similar form, with
Fork, about 10 ponies (16.1 km.) east of Hyrum, Cache County, Utah. Figure 71A is copied from such regular, fine, sharp

Walcott [1908d, Pl. X, fig. 8]. It is the type specimen. ofa :
sips SR Sane a ae radiating ribs, from the

Cambrian The largest ventral valve in the collection has a length of 10 mm.; width, 18 mm.

FoRMATION AND LOCALITY.—Middle Cambrian: (31c and 540)¢ About 900 feet (274.3 m.). above the Brigham
quartzite and 3,300 feet (1,005.8 m.) below the Upper Cambrian in the limestone forming 1b of the Ute limestone
[Walcott, 1908f, p. 196], in Blacksmith Fork Canyon, about 10 miles (16.1 km.) east of Hyrum, Cache County, Utah.

Eoorrtuis sp. undt. a (Pompecky).

Orthis sp., Pomprcxs, 1896, Jahrb. K.-k. geol. Reichsanstalt for 1895, Bd. 45, Hit. 3, p.514, Pl. XV, fig. 6. (Charac-
terized in German; see below for translation.)

Orthis (Plectorthis) sp. (Pompeckj), Waucorr (in part), 1905, Proc. U. 8. Nat. Mus., vol. 28, pp. 272-273. (Original
description copied.)

This species appears, from the illustration given by Pompeckj [1896b, Pl. XV, fig. 6], to
belong to the genus Hoorthis. The material is too imperfect for specific determination. The
original description is as follows:

Some impressions of dorsal valves depart from Orthis romingeri. 'The ribs are remarkably broad, flat, and separated.
by narrow interspaces; ribs may be observed to be split several times.

FORMATION AND LOCALITY.—Middle Cambrian: (345 [Pompeckj, 1896b, p. 514]) Greenish shale in the Paradoxides
zone, on the Dlouhé Hora, above the brook of Sbiroy, near Skrej, Bohemia, Austria-Hungary.

Eoortuis sp. undt. b (Pompeck)).

Orthis sp. Pomprcks, 1896, Jahrb. K.-k. geol. Reichsanstalt for 1895, Bd. 45, Hit. 3, p. 514, Pl. XV, fig. 7. (Char-
acterized in German; see p. 793 for translation.)

Orthis (Plectorthis) sp. (Pompeckj), Wat.corr (in part), 1905, Proc. U. S. Nat. Mus., vol. 28, pp. 272-273. (Original
description copied.)

a 540 is the type locality.

: BILLINGSELLIDA. 793

Pompeckj [1896b, p. 514] mentions another species of Orthis that appears to belong to the
genus Hoorthis. The material, which is too imperfect for specific determination, was described
as follows: —

The impression of a dorsal valve departs from Orthis romingeri in its greater breadth and less distinct ribbing.

FORMATION AND LOCALITY.—Middle Cambrian: (345e [Pompeckj, 1896b, p.514]) Greenish shale in the Paradoxides
zone in the gorge above Luh, near Skrej, Bohemia, Austria-Hungary.

Koorruis sp. undt. ¢ (Walcott).
Plate LXX XIX, figure 7.

Orthis (Plectorthis) sp. undt. Watcotr, 1906, Proc. U. S. Nat. Mus., vol. 30, p.571. (These various shells are described

and discussed essentially as below as sp. undt. c, d, and e.)

This species is represented by a single specimen of the ventral valve. Ventral valve
convex, with the apex curving gently downward from the highest point to the cardinal area,
transverse; length, 2.5 mm.; width, 3 mm.; hinge line a little shorter than the greatest width;
cardinal area sloping slightly forward from the hinge line.

Surface marked by about 16 strong, nearly regular, rounded, radiating ribs, that are
crossed by fine, concentric striz, lines of growth, and one strong ridge indicating interruption
of growth.

Observations —This little shell was at first placed with Hoorthis agreste (Walcott) (Pl.
LXXXIX, fig. 6), but further study showed that its greatest convexity, elevated apex, and
stronger ribs distinguished it from that species.

FORMATION AND LOCALITY.—Middle Cambrian: (€26) Near the top of the black oolite group in the uppermost

layers of the Changhia formation [Blackwelder, 1907a, p. 33 (part of the last list of fossils)]; 2 miles (3.2 km.) north-
northeast of Changhia, Shantung, China.

: Eoortuts sp. undt. d (Walcott).

Plate LX X XIX, figure 8.

A larger shell of the type of sp. undt. ce occurs in Shensi, in the central portion of the
Kichou formation. It has a length of 6.5 mm. and a width of 7.5 mm. The surface is
marked by numerous radiating ribs, similar to those of the shell from Changhia, also concen-
tric strize and several ridges resulting from interruption of growth.

FoRMATION AND LOCALITY.—Middle Cambrian: (C71) Massive cliff-making limestones in the central portion of

the Kichou formation [Willis and Blackwelder, 1907, pp. 139 and 145 (2d list of fossils)], 4 miles (6.4 km.) south-
southwest of Tungyu, Shansi, China.

EKoorrtuis sp. undt. e (Walcott).¢

A third shell that appears to be a dorsal valve was found associated with Middle Cambrian
trilobite fragments in limestone pebbles in river gravel. The surface is partly exfoliated,
but it shows rounded, radiating ribs and concentric ridges, similar to those on the two specimens
described above as sp. undt. ¢ and sp. undt. d.

FORMATION AND LOCALITY.—Upper Cambrian: (C67) Stream gravels used in making the railroad grade, 0.33 mile
(0.5 km.) west of the west city gate, Tsinan, Shantung, China.

Genus FINKELNBURGIA Walcott.

Orthis (Finkelnburgia) Watcort, 1905, Proc. U. S. Nat. Mus., vol. 28, pp. 277-278. (Characterized and discussed as
below as a new subgenus. ) :
Finkelnburgia Waucort, 1908, Smithsonian Misc. Coll., vol. 53, No. 4, Pl. XI, and pp. 142 and 148. (Classification
of genus.) ’
This genus is based upon two species that differ from Hoorthis in having thick shells and
strongly marked vascular trunks in the ventral valve. The type of the genus, Finkelnburgia
finkelnburgi. with its acuminate and sometimes alate cardinal extremities and subequally convex

aSee synonymy for Hoorthis sp. undt. c.

794 CAMBRIAN BRACHIOPODA.

valve, is a very strongly marked type; the second species, /’. osceola, has obtuse cardinal extrem- _

ities, and most of the examples closely resemble in form Hoorthis remnicha (Winchell). It is
only when the specimens from the fine-grained sandstone of Trempealeau are studied that one
finds the thick shell and strong interior markings that are unknown in species of the genus
Hoorthis.

This genus is named after Mr. W. A. Finkelnburg, of Winona, Minnesota, who has been
one of the most intelligent and enthusiastic collectors of Cambrian and Ordovician fossils in
Minnesota in recent years.

Type.—Orthis (Finkelnburgia) finkelnburg: Walcott.

FINKELNBURGIA FINKELNBURGI (Walcott)

Plate XCIII, figures 2, 2a-e.

Orthis (Finkelnburgia) finkelnburgi Waxtcotr, 1905, Proc. U. 8. Nat. Mus., vol. 28, pp. 278-279. (Described and dis-
cussed as below as a new species.)

Shell transverse with the cardinal extremities acuminate and in some examples almost
alate. On the ventral valve the hinge line slopes toward the beak at a low angle; in the dorsal
valve it is nearly straight. There is considerable variation in the height and width of the shell,
this feature depending upon the extension of the cardinal angles. The convexity of the valves
is subequal. In some examples the ventral valve is much more elevated and convex than in
others, and the same is true of the dorsal valve. A low, clearly defined mesial sinus occurs on
the dorsal valve, being strongest in young shells, and there is frequently a flattening of the
mesial area on the ventral valve.

The surface is marked by fine, rounded, radiating costz, crossed by concentric lines, and,
occasionally, ridges of growth. In a ventral valve 7 mm. in length, 11 mm. in width, there are
two coste in a distance of 1 millimeter.

The largest specimen of a ventral valve in the collection has a length of 10 mm. with a
width of 18 mm. ‘The average shell is less than 8 mm. in length.

The cardinal area of the ventral valve is relatively high. It extends backward over the
hinge line at an angle varying from 15° to 45° from the plane of the valve. The delthyrium is
of moderate width and apparently partly covered by a deltidium. The cardinal area of the
dorsal valve averages about one-half the height of that of the ventral valve, although in some
shells it is fully two-thirds as high. It extends backward at an angle of about 70° to the plane
of the valve. It is divided midway by a strong delthyrium. None of the specimens in the
collections show whether there was a chilidium present or not.

In the interior of the ventral valve the strong teeth were supported by dental plates that
extend to the bottom of the valve and bound the umbonal cavity (pseudospondylium). The
only traces of the vascular system are the bases of strong vascular trunks, as shown in Plate
XCIII, figure 2. The positions of the diductor and adductor muscle scars are shown in figure 2.
The latter appear to have been carried into a very narrow space on an elevated ridge between
the deep impressions made by the main vascular trunks; in figure 2a the points of attachment
of the muscles are well advanced into the valve.

In the interior of the dorsal valve a cast of the interior of the pseudocruralium appears to
have a small cardinal process, or callosity, but its presence is too doubtful to state that the
cardinal process is present; there are traces of a median septum shown on the central ridge
toward the center of the valve. The cardinal process occurs in the anterior half of the umbonal
cayity. The casts of the interior show that the crura are short and well defined, with relatively
strong dental sockets beside them. The only traces of the muscle scars observed are those of
the adductor, as shown in figure 2e.

Observations —The exterior surface and size of this shell recalls Finkelnburgia osceola
(Walcott). It differs, however, in the acuminate ventral angles and strongly convex dorsal
valve. In form the elongate cardinal angles relate this species to Otusia sandbergi (Winchell),
but im surface and interior markings it materially differs from the latter.

STROPHOMENID. 795

The specific name was given in honor of Mr. W. A. Finkelnburg.

FoRMATION AND LOCALITY.—Upper Cambrian: (78 and 78s) “‘St. Croix sandstone,’’ quarry near St. Croix River
in suburbs of Osceola, Polk County; (81) “‘St. Croix sandstone” 1 mile (1.6 km.) east-northeast of Devils Lake, Sauk
County; (81b) “‘St. Croix sandstone” near Devils Lake, Sauk County; and (88, 83’, 185b, and 185c)@‘‘ St. Croix sand-
stone”? near Trempealeau, Trempealeau County; all in Wisconsin.

(339f) “St. Croix sandstone” near Minneiska (Miniska) on Mississippi River near the line between Wabasha
and Winona counties, Minnesota.

HINKELNBURGIA OSCEOLA (Walcott).

Plate XCIII, figures 1, la—h.
Orthis (Finkelnburgia) osceola Waucott, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 279. (Discussed essentially as below
as a new species. )

The general form of this species is similar to that of Hoorthis remnicha (Winchell) except
that it is usually more transverse. It is a smaller shell, averaging for the ventral valve a
length of 8 mm. and width of 11 mm., while H. remnicha averages 12 mm. in length and 14 to
16 mm. in width in the adult shell. The radiating cost are more uniformly rounded and
regular, and more numerous, except when compared with the variety tezana. The shell of
Finkelnburgia osceola is thick, like other forms of the genus, with a result that the vascular
markings are definitely outlined. In figure 1d the vascular markings are beautifully shown;
also, the large main vascular sinuses so characteristic of many species of Billingsella. The
cardinal process and median septum are well brought out in the cast, figure 1f. Some of the
dorsal valves approach quite closely to those of H. remnicha sulcata (Walcott).

The specific name is derived from Osceola, Wisconsin.

FORMATION AND LOCALITY.—Upper Cambrian: “‘St. Croix sandstone” at the following localities: (78 and 78s)
Quarry near St. Croix River, in suburbs of Osceola, Polk County; (78b) 50 feet (15 m.) above St. Croix River, near
the landing at Osceola, Polk County; (79a) quarry and ledge 0.5 mile (0.8 km.) southeast of the county courthouse,
Menomonie, Dunn County; (80) 0.33 mile (1.1 km.) southwest of the railway depot, Menomonie, Dunn County;
(79b) near Hudson, St. Croix County; (80a) 4 miles (6.4 km.) north of Reedsburg, Sauk County; (83, 83’ and 135c)b
near Trempealeau, Trempealeau County; (85x) near Mazomanie, Dane County; and (828i) 0.33 mile (1.1 km.) west
of the railway station, Lodi, Columbia County; all in Wisconsin.

(339g) Just below the Dicellocephalus minnesotensis zone, near Winona, Winona County, Minnesota.
(341) Sandstone near Lansing, Allamakee County, Lowa.

FINKELNBURGIA OSCEOLA CORRUGATA (Walcott).

Orthis (Finkelnburgia) osceola corrugata WaucotT, 1905, Proc. U.S. Nat. Mus., vol. 28, p. 280. (Characterized as below
as a new variety.)
At two of the localities at which Finkelnburgia osceola (Walcott) occurs there are also found
a few specimens with strong concentric ridges formed by the piling up of lines of growth. The
shell has a corrugated appearance that is very distinctive, and it is designated a variety.

ForRMATION AND LOCALITY.—Upper Cambrian: (78 and 78s) “‘St. Croix sandstone,”’ quarry near St. Croix River, in
the suburbs of Osceola, Polk County, Wisconsin.
(339g) Just below the Dicellocephalus minnesotensis zone, near Winona, Winona County, Minnesota.

Superfamily STROPHOMENACEA Schuchert.
Family STROPHOMENID 4 King.
Subfamily RAFINESQUIN4® Schuchert.

Genus EOSTROPHOMENA Walcott.
[i@e, dawn; and Strophomena (ozpop%, a twist; and jj, the moon, a crescent).]

Strophomena (Eostrophomena) Watcort, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 256. (Characterized as below as a
new subgenus. )

Eostrophomena Waucort, 1908, Smithsonian Misc. Coll., vol. 53, No. 4, Pl. XI, and pp. 142 and 148. (Classification
of genus. )

283 is the type locality. b 83’ is the type locality.

796 CAMBRIAN BRACHIOPODA.

The description of the type species gives all that is known of the genus. It differs from
Strophomena in having the cardinal process in the dorsal valve merged into a ridge formed by
the extension of the crural plates along the posterior margin so as to cover the delthyrium and
unite at the median line.

Type.—Strophomena (Eostrophomena) elegantula Walcott. .

Observations.—The cardinal process is more like that of Orthothetes than that of Strophomena;
it differs from both in being more simple in its. construction. It is probable that there is a
group of shells having the characters of Hostrophomena elegantula (Walcott), but owing to the
difficulty of obtaining interiors of the valves, it is impossible to designate them. Strophomena
aurora Billings [1865a, p. 218] is one of these; also, Leptena decipiens [Billings, 1862c, p. 74].

EosTROPHOMENA ELEGANTULA (Walcott).

Plate XCV, figures 6, 6a—b.

Strophomena (Hostrophomena) elegantula Waxcort, 1905, Proc. U. 8. Nat. Mus., vol. 28, pp. 256-257. (Described ;

and discussed as below as a new species.)

Strophomena (Hostrophomena) walcotti Mosrre and Szcrrserc, 1906, Medd. fran Lunds Geol. Faltklubb, Ser. B,
No. 2 (Aftryck ur K. Fysiografiska Sallskapets Handl., N. F., Bd. 17), p. 71, Pl. 11, figs. 6, 6a—b ; Pl. III, fig. 16°.
(Described and discussed in Swedish. The specific name “‘walcotti” is proposed because of the preoccupation
of ‘‘elegantula.’’ The generic value now assigned to Hostrophomena permits the use of “‘elegantula.” Figs. 6,
6a-b, in common with the remaining figures on PI. II of Moberg and Segerberg’s paper, were copied from a
preliminary photograph of Pl. XCV of this monograph.) ,

General form transversely subsemicircular or subelliptical, greatest width at the straight
hinge line. Surface concayo-convex and marked by fine, radiating, even striz, separated into
flat bands by stronger and more prominent striz or ribs; fine concentric strie, and more or
less prominent lines of growth cross the radiating striz. The ventral valve is slightly convex,
with low umbo and small, incurved apex. The dorsal valve is flattened in the umbonal region
and concave toward the margins; the interior shows a narrow, rounded median furrow, also

rounded crural plates that unite with the cardinal process to form a continuous ridge covering.

the anterior portion of the delthyrium; the dental sockets appear to have been relatively large
and deep; the adductor muscle scars are a little to the front, as shown in figure 6b.

A ventral valve 6 mm. wide has a length of 4 mm., and a dorsal valve 5.5 mm. wide is
3 mm. in length.

Observations.—The concavo-convex shells and the ridge representing the cardinal process
place this little shell with the strophomenoid forms, but as no described genus possesses the
characters shown a genus is made to receive it.

FoRMATION AND LOCALITY.—Passage beds between the Upper Cambrian and the Ordovician: (810j) Ceratopyge
limestone, at Borgholm; (310 [Moberg and Segerberg, 1906, description of Pl. III]) Ceratopyge limestone (Zone 4) at

Ottenby; and (390e [Moberg and Segerberg, 1906, pp. 71 and 109]) ““Apatocephalus zone of the Ceratopyge suite,” at
Ottenby; all on Oeland Island, Sweden.

Superfamily PENTAMERACEA Schuchert.

Family SYNTROPHIID Schuchert.
Genus SWANTONIA Walcott. 4

Swantonia Waxcorr, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 296. (Mentioned as below as a new genus.)
Swantonia Watcort, 1908, Smithsonian Misc. Coll., vol. 53, No. 4, Pl. XI, and pp. 142 and 148. (Classification of
genus. )
The description of the type species includes that of the genus, as there is only one other
species now referred to the genus, and that is very imperfectly known.

a Prior to the definition of the genus Swantonia the species now placed under that genus were referred to the following genera:
Camerella Billings [1861b, p. 10; 1861c, p. 949; 1862e, Camarella ? Hall and Clarke [1893, p. 220].
Pp. 221; 1863, p. 284]. Protorhyncha ? Schuchert [1897, p. 334].
Camarella Walcott [1886b, p. 122; 1891a, p. 613).

SYNTROPHIID. Oe

Type.— Camerella antigua Billings [1861b, p. 10].
The generic name is derived dean the town of Swanton, Vermont, near which the type
species occurs.

SWANTONIA ANTIQUATS (Billings).
v Plate CLV, figures 5, 5a—b.

Camerella antiquata Brutines, 1861, Geol. Survey Canada, Paleozoic Fossils, vol. 1, pp. 10-11, fig. 13, p. 10. (De-
scribed and discussed as a new species.)

Camerella antiquata Biut1nes, 1861, Report on the Geology of Vermont, vol. 2, p. 949, fig. 353. (Copy of preceding
reference.)

Camerella antiquata Brtu1nes, 1862, Report on the Economic Geology of Vermont, by Hager, p. 221, fig. 353. (Copy
of Billings, 1861b, pp. 10-11, and fig. 13.)
Camerella antiquata Brtuines, 1863, Geol. Survey Canada, Fifteenth Rept. Progress, fig. 290, p. 284. (No text refer-
ence. Fig. 290 is copied from Billings, 1861b, fig. 13, p. 10.)
—Camarella antiquata Billings, Watcorr, 1886, Bull. U. S. Geol. Survey No. 30, pp. 122-123, Pl. VII, fig. 8. (Original
description, Billings, 1861b, pp. 10-11, copied. The specimen represented by fig. 8 is redrawn in this mono-
graph, Pl. CIV, fig. 5.)
~Camarella antiquata Billings, Watcorr, 1891, Tenth Ann. Rept. U. S. Geol. Survey, p. 613, Pl. LX XII, fig. 3. (No
text reference. Fig. 3 is copied from fig. 8 of the preceding reference.)
Camarella ? antiquata Belling, Haut and CiarKe, 1893, Nat. Hist. New York, Paleontology, vol. 8, pt. 2, pp. 220-221.
(Mentioned in discussion of genus Camarella.)
Protorhyncha ? antiquata (Billings), ScHucHERT, 1897, Bull. U.S. Geol. Survey No. 87, p.334. (Merely changes generic
reference. )
—Swantonia antiquata (Billings), Watcort, 1905, Proc. U. 8. Nat. Mus., vol. 28, pp. 296-297. (Described and discussed
as below.)

Ventral valve ovate, moderately convex; apex pointed and incurved over the area nearly
to the plane of the margins of the valve; surface marked by from 8 to 12 or more rounded
ribs that extend back well toward the apex; a slight flattening of the median portion suggests
that a shallow median sinus may be found on old shells. The shell illustrated has a length
and width of 11 mm.

A cast of the interior of a ventral valve shows no traces of muscle scars or vascular mark-
ings; two strong teeth are indicated, also a narrow, strong, concave shelf or area; the area or
shelf is free from contact with the bottom of the sale, a recess or chamber existing beneath it.

Observations—The area or shelf may be somnetdleved as a short, free spondylium, corre-
sponding to the short spondylium of Camarella volborthi Billings as illustrated by Hall and
Clarke [1892c, Pl. LXII, fig. 18]. Swantonia is closely related to Camarella, but it differs in
the absence of a supporting median septum beneath the spondylium of the ventral valve.
No specimens of the dorsal valve have been observed.

FORMATION AND LOCALITY.—Lower Cambrian: (319e)¢ Sandy shales 2 miles (3.2 km.) east of Swanton, Franklin
County, Vermont.

SWANTONIA WEEKSI Walcott.
y,
Plate CIV, figure 6.

Swantonia weeksi Watcort, 1905, Proc. U. 8. Nat. Mus., vol. 28, p. 297. (Characterized as below as a new species.)

This shell has the general form of Swantonia antiquata (Billings), but the ribs are finer,
more numerous, and crossed by fine, sharp, concentric striw. Only the exterior of the ventral
valve appears to be represented in the collection made by Mr. F. B. Weeks.

FoRMATION AND LOCALITY.—Lower Cambrian: (1v) Shales of No. 3 of the Silver Peak group, Barrel Spring
section [Walcott, 1908f, p. 189], 3 miles (4.8 km.) north of Valcalda Spring and 4 miles (6.4 km.) west-northwest of the
Drinkwater mine, Silver Peak quadrangle (U. 8. Geol. Survey), Esmeralda County, Nevada.

a Billings [1861b, p. 11] gives the locality as 1.5 miles (2.4 km.) east of Swanton, Vermont.

798 CAMBRIAN BRACHIOPODA.

Genus SYNTROPHIA Hall and Clarke. @

Syntrophia Hart and CuarKe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, footnote, p. 270. (Discusses
species which appear to belong to a distinct genus and announces the future use of the term Syntropha to
include them.) :

Syntrophia Hatt and Cuarke, 1893, idem, pt. 2, pp. 216-218. (Described and discussed as a new genus, copying
the original note proposing the genus. The description of ‘‘ Triplesia lateralis” Whitfield, which is given on
p. 217, is copied in this monograph; see below.)

Syntrophia Hall and Clarke, Haux, 1894, Thirteenth Ann. Rept. State Geologist New York for 1893, vol. 2, pp. 836-
837. (Copies the description of ‘‘ Triplesia lateralis ’’ given on p. 217 of the preceding reference. )

Syntrophia Hall and Clarke, Waxcort (in part), 1905, Proc. U. S. Nat. Mus., vol. 28, pp. 288-289. (Gives an essential
copy of the description of ‘‘ Triplesia lateralis” given by Hall and Clarke, 1893b, p. 217, a description which
is copied below, and discusses the genus essentially as below. Species were included in the genus which are
now placed under Huenella.) ;

Syntrophia Hall and Clarke, Grasavu and Sumer, 1907, North American Index Fossils, vol. 1, p. 270. (Described.)

Syntrophia Hall and Clarke, Waucorr, 1908, Smithsonian Mise. Coll., vol. 53, No. 4, Pl. XI, and pp. 142 and 148.
(Classification of genus.)

The description of ‘‘ Triplesia lateralis” by Hall and Clarke [1893b, p. 217] follows:

Shell transversely elongate, biconvex with a straight hinge line whose length nearly equals the greatest diameter
of the valves, and each valve is medially divided by an open delthyrium. The external surface is smooth, with fine
concentric lines visible only about the margins; the inner shell layers show a strongly fibrous radiating structure
without punctation. The pedicle valve bears a more or less clearly developed median sinus and the brachial valve
a broad, indistinct fold.

On the interior the teeth are very small, lying at the extremities of the delthyrial margins and supported by
dental plates which converge and unite before reaching the bottom of the valve. Thus is formed a deep but short
spondylium, which is supported, near its apical portion, by a median septum, but is free for fully one-half its length.

In the brachial valve there are also two convergent plates bounding the deltidial cavity, larger and stronger than
those of the opposite valve. These plates may rest upon the bottom of the valve, and probably always do so toward
the posterior extremity, but anteriorly they become free, forming a spondylium which is supported by a median septum
extending beyond the anterior edge of the plate. Thus these two valves which are very similar in exterior, the pedicle
valve being only slightly the more convex and with a low median sinus, are also closely alike on the interior, each
being furnished with a spondylium.

Type.— Triplesia lateralis Whitfield.

Observations.—Hall and Clarke [1893b, p. 216] referred Orthis barabuensis and Triplesia
primordialis among Cambrian species to Syntrophia, and of Ordovician species, Triplesva
lateralis, Stricklandinia? arethusa, S.? arachne, and Camarella calcifera.

Orthis? armada Billings, of the Lower Ordovician, certainly has a close resemblance in the
spondylium of its ventral valve to this genus, and it may represent a radially striated form, as
suggested by Hall and Clarke [1893b, p. 218]. Concerning the relations of Syntrophia to Strick-
landinia, they consider that the structures represented in the species referred to the former
genus may be the equivalents of those represented by the Stricklandinias of the later Silurian
and Devonian. Billings [1862b, p. 84] noted the relationship existing between his Camarella
calcifera and Stricklandinia. It is probable that S.? arachne, S. arethusa, and similar forms
should be referred to a distinct genus. They are not typical Stricklandinias and they differ
in surface and shape from Syntrophia lateralis.

The Cambrian type of Syntrophia is S. rotundata of the Upper Cambrian. It has a spondyl-
ium in each valve supported by a median septum, and a short area divided by a large open
delthyrium.

The structure of the shell of Syntrophia is fibrous, with rows of minute pores between
the fibers.

aThe synonymy for this genus does not give a complete record of the various genera under which the species now included in Syntrophia were
formerly placed; it gives only those references in which the genus is discussed or described. To complete the record for the species taken up in

this monograph the following mere generic references are listed: ‘
Camerella Billings [1861a, p. 318; 1863, p. 231]. Triptesia Whitfield [1882, p. 172].
Orthis A. Winchell (1864, p. 228). Triplesia Walcott [1884b, p. 75].
Camerella Billings [1865a, p. 220]. Triplesia Whitfield [1886, p. 303).
Triplesia Whitfield [1878, p. 51). Triplecia Hall and Clarke [1892c, p. 270}.

Leptzena Whitfield [1878, p. 60; 1882, pp. 171and 195}.

SYNTROPHIIDA. 78

All of the species of the Syntrophiide with nonplicated, smooth surface and spondylium
raised on a median septum are referred to Syntrophia, and the species with a more or less
plicate surface, with sessile spondylium or pseudospondylium, to the genus Huenella. The
nonplicate or smooth species are: S. cambria and S.? wnxia of the Middle Cambrian; S. alata,
S. barabuensis, S. campbell, S. orthia, S. primordialis, and S. rotundata of the Upper Cambrian;
and S. calerfera, S. lateralis, and S. nundina of the Ordovician.

SYNTROPHIA ALATA Walcott.
Plate CIII, figures 3, 3a-e.
Syntrophia alata Waucort, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 290. (Characterized as below as a new species.)

This species is characterized by its transverse form and extended cardinal angles. Exterior
surface marked by concentric striz and lines of growth and interior surface by fine, radiating
stris. A transverse section of the ventral valve at the umbo shows the spondylium with a
strong median septum supporting it. The interior of the ventral valve was marked by two
strong main vascular sinuses starting from the sides of the spondylium.

FORMATION AND LOCALITY.—Upper Cambrian: (69) Limestone near Honey Creek, Burnet County, Texas.
SYNTROPHIA BARABUENSIS (A. Winchell).

Plate CII, figures 1, la-g.

Orthis barabuensis A. WINCHELL, 1864, Am. Jour. Sci., 2d ser., vol. 37, p. 228. (Described and discussed as a new
species.)

Leptxna barabuensis (Winchell), WuitrieLp, 1878, Ann. Rept. Wisconsin Geol. Survey for 1877, p. 60.

Leptxna barabuensis (Winchell), Wurrrretp, 1882, Geology of Wisconsin, vol. 4, pt. 3, pp. 171-172, PI. I, figs. 6 and 7.
(Described and discussed; see below for copy.)

Leptzna barabuensis Winchell, WurirrreLp, 1882, idem, p. 195, Pl. III, fig. 6. (Described from a higher horizon than
that containing the specimens referred to in the aueeadtiay, )

Syntrophia barabuensis (Winchell), Haun and CrarKe, 1893, Nat. Hist. New one Paleontology, vol. 8, pt. 2, p. 216.
(Changes generic reference.)

Syntrophia barabuensis (Winchell), Waxcorr, 1905, Proc. U. S. Nat. Mus., vol. 27, pp. 290-291. (Description by
Whitfield copied, and species discussed as below.)

The description by Whitfield [1882, pp. 171-172] follows:

Shell of medium size or smaller, measuring about half an inch or less than half an inch along the hinge line;
form semielliptical, longest on the hinge and more than half as wide again aslong; extremities of the hinge often sub-
mucronate; front of the valves rounded or slightly emarginate in the middle. Ventral valve the most convex, and
marked by a strong, angular mesial elevation, nearly one-fourth as wide on the front of the valve as the width of the
shell; area moderately high and nearly in the plane of the valve; cardinal borders very gradually sloping from the
center to the extremities of the cardinal line. Dorsal valve less convex than the opposite, and marked by a suban-
cular mesial depression, corresponding to the fold of the opposite valve; area linear. Surface of the shell apparently
smooth, or at least so far as can be determined from either the internal casts or from the matrix.

I had some doubt regarding the positive identity of this species with that described by Professor Winchell [1864,
p. 228] in consequence of the following remarks which occur in his description: “‘Surface with sixteen or eighteen ribs
visible on the casts, the strongest of which limit the mesial sinus,’’ and again, ‘‘apparently of the type of Orthis biforta.”’
In examining a number of specimens, I had not been able to detect any striz or ribs, and felt somewhat inclined to
regard it as a distinct species from that one. I have, however, through the kindness of Prof. W. [Winchell], been able
to make a direct comparison with one of his original specimens, and should consider them as identical. The specimen
sent me has the mesial fold (of the ventral valve) remarkably strongly defined by a depressed line on each margin, the
center appearing tumid, which I think is in part due to accident. The specimen corresponds closely with the ventral
valve we have figured, except in the strongly defined mesial fold.

Observations.—This is the same type of Syntrophia as S. primordialis. It differs in its
more rounded outlines, shallow, rounded sinus in the ventral valve, and, usually, a less pro-
nounced fold on the dorsal valve. Evidence of a short median septum at the end of a very
short spondylium in the dorsal valve is shown by one east (PI. CII, fig. 1g).

The species derives its specific name from its occurrence at Devils Lake, which is near
Baraboo, Sauk County, Wisconsin.

FORMATION AND LocALIry.—Upper Cambrian: ‘‘St. Croix sandstone” at the following localities: (328 [ Whitfield,
1882, p. 172]) Upper layers near the north end of Devils Lake, Sauk County; (81b) near Devils Lake, Sauk County; (810)

800 CAMBRIAN BRACHIOPODA.

on the railroad track below the Cliff House, Devils Lake, Sauk County; (88) near Trempealeau, Trempealeau County;
(78) quarry near St. Croix River in the suburbs of Osceola, Polk County; and (184a) in a quarry 1 mile (1.6 km.) south-
east of the county courthouse in Menomonie, Dunn County; all in Wisconsin.

SYNTROPHIA CALCIFERA (Billings)
Plate CIV, figures 1, la-i.

Camerella calcifera BrxuiNGs, 1861, Canadian Naturalist, vol. 6, pp. 318-320, figs. 3a-c, p. 319. (Described and discussed
as a new species. Figs. 3a-c are copied in this monograph, Pl. CIV, figs. 1, la, and 1b, respectively.)

Camarella calcifera Brt1nes, 1863, Geol. Survey Canada, Fifteenth Rept. Progress, figs. 247a-c, p. 231. (No text

reference. Figs. 247a-c are copied from figs. 3a-c of the preceding reference.)

Camerella caleifera Brxuines, 1865, Geol. Survey Canada, Paleozoic Fossils, vol. 1, p. 220. (Localities mentioned.)

Triplecia? calcifera (Billings), Hain and CirarKeE, 1892, Nat. Hist., New York, Paleontology, vol. 8, pt. 1, p.270. (Merely
changes generic reference.) f

Syntrophia? calcifera (Billings), Hat and CrarKe, 1893, idem, pt. 2, p. 218, Pl. LXII, fig. 24. (Changes generic
reference.)

Syntrophia calcifera differs from S. nundina im its more pointed and incurved apex, stronger
ventral sinus, and dorsal fold. It is more convex and rotund than S. primordialis.

The only interior parts known are in the form of a cast illustrated by Billings [1861a, fig. 3c,
p- 319] and copied in Plate CIV, figure 1b; this indicates a well-developed spondylium and
a median supporting septum in the ventral valve.

The form owes its specific name to its occurrence in the “‘calciferous sandrock.”

ForMATION AND LOCALITY.—Lower Ordovician: (319t)@ ‘‘Calciferous sandrock” at St. Timothy on the St. Law-
rence, near the head of the Beauharnois Canal; (319u [Billings, 1861a, p. 320]) “‘calciferous sandrock” in the Township
of Edwardstown, between Beauharnois and Lake
Champlain; (392) @ at Nortons Creek; (392j) @ lime-
stones of the ‘‘Quebec grouwp’’ at Point Levis; and

Province of Quebec, Canada.

(314c) @ Nodules of white limestone belonging
to Division P of Billings’s section at Cow Head,
Newfoundland.

SYNTROPHIA CAMBRIA Walcott.

Text figures 72A—D.

Misc. Coll., vol. 53, No. 3, pp. 106-107,
Pl. X, figs. 11 and lla. (Described and
discussed as a new species. With the ex-
ception of the third paragraph the reference
iscopied below. Figs. 11 and llaare copied
in this monograph as figs. 72B and 72C, re-
spectively.)

FIGURE 72.—Syntrophia cambria Walcott. A, A’, Top view and side outline of
ventral valve (U. S. Nat. Mus. Cat. No. 57029a). B, Ventral valve, the type General form transversely oval,

specimen (U. §. Nat. Mus. Cat. No. 52477a). C, Dorsal valve (U.S. Nat. strongly convex but not rotund. Ven-

Mus. Cat. No. 52478). D, Partly exfoliated ventral valve (U. S. Nat. Mus. - s :
Gat ou soa7i0): tral valve moderately convex, with the

Figures 72B and 72C are copied from Walcott [1908d, Pl. X, figs. 11 and 11a). frontal margim in adult shells prolonged;
‘The specimen represented by figure 72C is from Locality 84m; those represented a flattened median sinus begins on the
by figures 72A, 72B, and 72D are from Locality 32e; and that represented by figure D ‘ Sree
72A is from Locality 81c, all in the Middle Cambrian of northeastern Utah. umbo and widens to two-thirds the

width of the shell in front; area un-

known. Dorsal valve moderately convex except on the median fold, which is rounded but
not unusually prominent; area unknown. ;

Surface marked by a few concentric lines of growth. The largest dorsal valve has a length

of 8 mm.; width, 11 mm. A ventral valve 9 mm. in length has a width of 14 mm.

a Billings, 1865a, p. 220.

(392i)@ limestone at Phillipsburgh; all in the .

Syntrophia cambria Waxcorr, 1908, Smithsonian _

SYNTROPHIID. 801

Observations.—In form this species is usually most nearly related to Syntrophia calcifera
(Billings) (Pl. CIV, figs. 1, la-1). It differs in having a less clearly defined beak and less promi-
nent fold on the dorsal valve. There are many poimts in common between Syntrophia cambria
and S. nundina Walcott (Pl. CI, figs. 4, 4a—c), but they differ in the shorter beak and sharper
median fold of the latter. Syntrophia cambria occurs in the Wasatch range, about 4,500 feet
below the base of the Ordovician, while S. calcifera and S. nundina occur in the Lower Ordovi-
cian. It is the oldest species of the genus and is of interest also on account of being closely
related in form to the Ordovician species mentioned.

FoRMATION AND LOCALITY.—Middle Cambrian: (31c¢ and 540) 900 feet (274.3 m.) above the Brigham quartzite and
3,300 feet (1,005.8 m.) below the Upper Cambrian, in the limestone forming 1b of the Ute limestone [Walcott, 1908,
p. 196], in Blacksmith Fork Canyon, about 10 miles (16.1 km.) east of Hyrum, Cache County; (32e) the same strati-
graphic horizon as Locality 31¢ just south of the south fork of Paradise Dry Canyon (Hast Fork), east of Paradise, Cache

County; and (34m) limestone about 765 feet (233.2 m.) above the Brigham quartzite [Walcott, 1908a, p. 8], 1 mile
(1.6 km.) northwest of Geneva (Copenhagen), east of Brigham, Boxelder County; all in Utah.

SYNTROPHIA CAMPBELLI Walcott.

Text figures 73A—F.

Syntrophia campbelli Waxcorr, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, pp. 107-108, Pl. X, figs. 9, 9a-c. (De-
scribed and discussed as below as a new species. Figs. 9, 9a-c are copied in this monograph as figs. 73B, 730,
73E, and 73F, respectively.)

General form rotund, unequally biconvex; hinge line short. Ventral valve moderately
convex, exclusive of the prolonged frontal margin; it is depressed toward the front in adult

FIGURE 73.—Syntrophia campbelli Walcott. A, Ventral valve, the type specimen (U. S. Nat. Mus. Cat. No. 52480f). B, Cast of ventral valve,
showing cast of septum supporting the spondylium (U.S. Nat. Mus. Cat. No. 524802). C, C’, Dorsal valve(U. S. Nat. Mus. Cat. No. 52480b).
D, Dorsal valve (U. S. Nat. Mus. Cat. No. 52480e). E, Section of ventral valve, showing cast of septum and spondylium (U.S. Nat. Mus.
Cat. No. 52480c). F, Cast of dorsal valve, showing cast of spondylium (U.S. Nat. Mus. Cat. No. 52480d).

The specimens represented are from Locality 12q, Upper Cambrian, near Rogersville, Tennessee. Figures 73B, 73C, 73H, and 73F are
copied from Walcott [1908d, Pl. X, figs. 9, 9a-c, respectively].

shells by a broad median sinus that disappears on the umbo; area short and divided midway by a
relatively large, open, triangular delthyrium. Dorsal valve convex with an elevated, reia-
tively narrow median fold that does not extend back to the beak; area short and divided by
a strong, open, triangular delthyrium.

Surface marked by concentric striz and a few strong lines of growth. The largest shell
is represented by a dorsal valve that has a length of 12 mm.; width, 14mm. A ventral valve
7 mam. in length has a width of 11 mm.

Casts of the ventral valve show a spondylium supported on a septum that extended from
the beak about one-third the distance to the front margin. The spondylium of the dorsal
valve rests directly on the interior of the shell without trace of a supporting median septum.

62667°—vou 51, pr 1—12——_51

802 CAMBRIAN BRACHIOPODA. j

Observations—The young shells of this species are almost evenly convex, the fold of the
dorsal valve and the sinus of the ventral valve of the adult shell not having developed. The
characteristic spondylium of each valve is shown in the youngest shells observed. The general
form of Syntrophia campbelli is much like that of Syntrophia rotundata Walcott (Pl. CIIL, figs.
4, 4a-c) and somewhat like that of Huenella texana (Walcott) (Pl. CIII, figs. 1, la-g). It
differs from the former in having the spondylium of the dorsal valve resting on the interior of
‘the shell and not supported on a septum, in this respect resembling the spondylium of Hueneila
texana (Walcott) (Pl. CIII, figs. 1h, 11). Some shells have a somewhat transverse posterior
margin like that of H. texana, but the larger number have the broadly acuminate outline of
S. rotundata. The muscle scars of the dorsal valve, as far as known, are similar to those of
Huenella abnormis (Walcott) (Pl. CII, figs. 21, 2s).

The specific name was given in honor of Mr. M. R. Campbell of the United States Geological
Survey, who collected the specimens.

FoRMATION AND LOCALITY.—Upper Cambrian: (12q) Knox dolomite, on Bunker Hill, 6 miles (9.6 km.) northeast
of Rogersville [Keith, 1905, areal geology sheet], Hawkins County, Tennessee.

SYNTROPHIA LATERALIS (Whitfield).

Text figure 11, page 299; Plate CII, figures 6, 6a-g.

Triplesia lateralis WHITFIELD, 1886, Bull. Am. Mus. Nat. Hist. No. 8, p. 303, Pl. XXIV, figs. 9-11. (Described as
a new species.)

Syntrophia lateralis (Whitfield), Hatt and CuarKe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, footnote,
p. 270. (Generic reference changed.)

Syntrophia lateralis (Whitfield), Hat and CuarKe, 1893, idem, vol. 8, pt. 2, p. 217, Pl. LXII, figs. 1-10. (Described,
giving on p. 216 the footnote referred to in the preceding reference. The description of this species is copied
in this monograph, under the genus Syntrophia.’ Figs. 9 and 10 are copied in this monograph, Pl. CII, figs.
6f and 6g, respectively.)

Syntrophia lateralis (Whitfield), Hatt and CuarKe, 1894, Thirteenth Ann. Rept. State Geologist New York for 1893,
vol. 2, pp. 836-837, Pl. XLV, figs. 7-12. (Copy of the description given on p. 217 of the preceding reference.
Figs. 7-12 are copied from Hall and Clarke, 1893b, Pl. LXII, figs. 1, 2, 6, 9, 5, and 10, respectively. )

I have illustrated a few of the shells representing the species that, taken with those of
Hall and Clarke in part 2 of volume 8 of their great work, illustrate about all that is known
of S. lateralis. (See p. 798 for a copy of Hall and Clarke’s description of the species.)

ForMATION AND LOCALITY.—Lower Ordovician: (227) Limestone near Fort Cassin, Addison County, Vermont.
SYNTROPHIA NUNDINA Walcott.

Plate CII, figures 4, 4a-d.

Triplesia calcifera Waucorr [not Biniines], 1884, Mon. U. S. Geol. Survey, vol. 8, pp. 75-76, Pl. XI, figs. 7 and 8.
(Characterized. The specimens represented by figs. 7 and 8 are redrawn in this monograph, Pl. CII, figs. 4
and 4a, respectively.)

Syntrophia nundina Waucort, 1905, Proc. U. §. Nat. Mus., vol. 28, p. 292. (Characterized as below as a new species.)

Syntrophia calcifera Walcott, GRaBav and Sumer, 1907, North American Index Fossils, vol. 1, p. 271, figs. 325. (De-
scribed. The two figures in fig. 325 are copied from Walcott, 1884b, Pl. XI, figs. 7 and 8, respectively.)

The nonplicate, convex species that is found in the Lower Ordovician of the western
United States has usually been referred to Camerella or Triplesia caleifera. It is much like
the latter but differs in being less convex, with apex of valves less pomted and incurved.

FORMATION AND LOCALITY.—Lower Ordovician: Pogonip limestone at the following localities: (63) Northeast of
Adams Hill; (201a) east slope of the ridge east of Hamburg Ridge; (203) on spur on ridge extending southwest from
Wood Cone; (204) on the lower part of the eastern slope of the ridge east of Hamburg Ridge, facing Secret Canyon road;
and (209) on the west side of Goodwin Canyon; all in the Eureka district [Hague, 1892, Atlas], Eureka County, Nevada.

(185z) Limestones at the base of the Lower Ordovician [Walcott, 1908f, p. 191], in Blacksmith Fork Canyon,
about 9 miles (14.4 km.) east of Hyrum, Cache County, Utah.

(186 and 186a) Near line of contact between red and gray Ordovician limestone, in red siliceous limestone, 30
to 35 feet (9.1 to 10.7 m.) above the pre-Cambrian rocks, Williams Canyon, Manitou, El Paso County, Colorado.

Upper Cambrian: (54b) About 1,200 feet (365.8 m.) above the Middle Cambrian and 25 feet (7.6 m.) below the
top of the Upper Cambrian in the upper part of the limestone forming 1 of the St. Charles formation [Walcott, 1908f,

SYNTROPHIID. 805:

p. 191]; and (54c) about 1,100 feet (335.3 m.) above the Middle Cambrian and 120 feet (36.6 m.) below the top of the’
Upper Cambrian in the central part of the limestone forming 1 of the St. Charles formation [Walcott, 1908i, p. 192];
both in Blacksmith Fork Canyon about 10 miles (16.1 km.) east of Hyrum, Cache County, Utah.
A specimen (Pl. CII, fig. 4d) that is somewhat doubtfully referred to this species occurs

at the following locality:

Upper Cambrian: (329a) Limestone on Ute Peak, in the Wasatch Mountains east of Cache Valley, Cache County,
Utah.

SYNTROPHIA ORTHIA Walcott.

Plate CIV, figures 4, 4a-b.
Syntrophia orthia Waxcort, 1905, Proc. U.S. Nat. Mus., vol. 29, pp. 11-12. (Described and discussed as a new species.)

General form irregularly oval, with the ventral view obtusely angular toward the apex;
rounded, biconvex, with a deep mesial sinus on the ventral valve and a strong median fold on
the anterior half of the dorsal valve. Surface smooth, with the exception of a few concentric
striz and lines of growth. The ventral valve has a strong median sinus that occupies about
one-third of the width of the valve at the anterior margin and projects forward to fit into the
sinus in the front of the margin of the dorsal valve; the sides of the median sinus are elevated,
and with the downward-sloping lateral slopes form a strong, rounded ridge on each side of the
sinus; none of the specimens in the collection show the area, but from the profile of the valve
it must have been of moderate height, with a rather sharp apex curving over it.

Dorsal valve with a minute apex, from which a narrow, slightly developed median fold
extends to about the posterior fourth of the shell, where it becomes elevated, and, widening,
extends forward to the front margin; the remaining portions of the surface are uniformly convex,
sloping away from the median fold to the margins of the valve.

Nothing is known of the interior of either valve.

Observations —In general form this species resembles Syntrophia primordialis (Whitfield)
of the “‘St. Croix sandstone” of Wisconsin. It differs in its more rounded, irregularly oval form
and the very large median sinus of the ventral valve.

ForMATION AND LOCALITY.—Upper Cambrian: (C54) Lower part of the Chaumitien limestone [Blackwelder,
1907a, p. 42 (part of last list of fossils)], 0.66 mile (1.1 km.) west of Tsinan; (€56) same horizon as Locality C54 at
Pagoda Hill [Blackwelder, 1907a, p. 42 (part of last list of fossils)], 1 mile (1.6 km.) west of Tsinan; and (C64) upper
limestone member of the Kiulung group [Blackwelder, 1907a, pp. 37 and 42 (first list of fossils), and fig. 10 (bed 20),
p. 38], 2.7 miles (4.3 km.) southwest of Yenchuang, Sintai district; all in Shantung, China.

SYNTROPHIA PRIMORDIALIS (Whitfield).
Plate CII, figures 2, 2a-e.

Triplesia primordialis WarTriELD, 1878, Ann. Rept. Wisconsin Geol. Survey for 1877, p. 51. (Described.)

Triplesia primordialis WHITFIELD, 1882, Geol. Wisconsin, vol. 4, pt. 3, p. 172, Pl. X, figs. 1 and 2. (Described and
discussed, the first paragraph being copied below.)

Triplecia? primordialis Whitfield, Haun and CuarxKe, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, p. 270,
footnote. (Questions generic reference.)

Syntrophia primordialis (Whitfield), Hatt and CLarKe, 1893, idem, pt. 2, p. 218. (Changes generic reference. )

Syntrophia primordialis (Whitfield), Waxcort, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 292. (Whitfield’s description,
1882, p. 172, copied and species discussed as below.)

The description by Whitfield [1882, p. 172] follows:

Shell small, measuring less than half an inch in width; transversely oval in outline, and quite ventricose in profile;
hinge line straight and about half as long as the width of the shell below; area narrow. Ventral valve with a strongly
depressed, rather narrow and rounded mesial sinus. Dorsal valve with a narrow, sharply elevated fold not extending
quite to the beak; sides of the valve rounded. Surface smooth in the casts, but presenting the appearance of having
been externally striate. Processes in the interior of the dorsal valve apparently forming a small spoon-shaped pit at
the beak.

Observations.—Casts of the interior show the form of the spondylium and supporting
median septum in the ventral valve; also, a small short spondylium in the ventral valve, which
appears to be attached to the bottom of the valve without a median septum.

804 CAMBRIAN BRACHIOPODA.

This species differs from Syntrophia barabuensis (Winchell) in its smaller size, less trans-
verse outline, and more pronounced mesial depression on the ventral valve. Some specimens
of the dorsal valves of the two species are very similar. These are shown by Plate CII,
figures 1f and 2c. Some of the shells approach certain forms of S. calcifera, but the larger
number are less convex and more transverse and with more obtuse cardinal angles. A shell
closely allied to S. primordialis, and apparently identical, occurs in the limestone of the Reagan
sandstone of Oklahoma. Only the exterior is known.

FORMATION AND LOCALITY.—Upper Cambrian: “St. Croix sandstone” at the following localities: (99) Minneiska
(Miniska), on Mississippi River, near the line between Wabasha and Winona counties; (339d) Taylors Falls, Chisago
County; (84a) at River Junction, Houston County, 20 miles (32.2 km.) below Dresbach, and (339g) just below the
Dikellocephalus minnesotensis beds, near Winona, Winona County; all in Minnesota.

(828k) ‘‘St. Croix sandstone” at Roche & Cris Bluff, Adams County, ‘Wisconsin.

(9u) About 195 feet (59.4 m.) above the porphyry contact in the limestones of the Reagan sandstone, in SH. $
NE. }sec. 2, T. 4N., R. 13 W., 15 miles (24.2 km.) northwest of Fort Sill, Comanche County; and (12n) limestones
of the Reagan sandstone (in the section 7 miles (11.2 km.) north of Springer this horizon is about 240 feet (73 m.) above
the porphyry contact and 40 feet (12 m.) below the Arbuckle limestone), NW. }sec. 1, T.28., R.1E., Ardmore quad-
rangle (U. S. Geol. Survey), Carter County; both in Oklahoma.

(168) Limestones on north side of Tepee Creek, near the road from Sheridan to Dome Lake, Bighorn Mountains,
Sheridan County, Wyoming.

SYNTROPHIA PRIMORDIALIS ARGIA Walcott.

Plate CII, figure 3.
{

Syntrophia primordialis argia Waxcort, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 293. (Characterized as below asa new
variety.)

This specimen is separated as a variety of Syntrophia primordialis (Whitfield) on account
of its less convexity and more shallow median sinus, which has three rudimentary plications in it.
ForRMATION AND LOCALITY.—Upper Cambrian: (97) ‘‘St. Croix sandstone” at Reads Landing, foot of Lake Pepin,

Wabasha County, Minnesota.
SYNTROPHIA ROTUNDATA Walcott.

Plate CIII, figures 4, 4a-e.

Syntrophia rotundata WALcortT, 1905, Proc. U. S. Nat. Mus., vol. 28, pp. 293-294. (Described and discussed as below
as a new species. )

General form rotund, unequally biconvex; hinge line short. Surface marked by fine,
concentric strie and low, imbricating varices of growth. The largest shell observed has a
width of 13 mm.; length, 11 mm. Ventral valve convex at the umbo and beak, but depressed
toward the front by a strong, broad, and deep median sinus. Area low, short, and divided
midway by a relatively large triangular delthyrium. Transverse sections of the umbo near
the beak show the cross section of a well-developed spondylium supported on a median septum.
Dorsal valve about as convex as the ventral on the umbo, but the strong, broad median fold
makes it strongly convex. Cross sections at the umbo show a spondylium and supporting
septum very much like that in the ventral valve.

Observations.—This species is taken as the Cambrian representative of the genus Syn-
trophia. It has a spondylium in each valve supported by a median septum in the same manner
as in the Ordovician type of the genus S. lateralis. Its rotund form, deep ventral sinus, and
strong dorsal fold serve to distinguish S. rotwndata from other species of the genus.

FoRMATION AND LOCALITY.—Upper Cambrian: (14k) Limestone on Wolf Creek, 15 miles (24.2 km.) west-south-
west of Sheridan, Bighorn Mountains, Sheridan County, Wyoming.

SynrropuHia ? unx1A Walcott.

if Text figure 74, page 805.
Syntrophia? unxia Watcort, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, pp. 108-109, Pl. X, fig. 10. (Discussed
as below asa new species. Fig. 10 is copied on p. 805 as fig. 74.)
This species is represented by a single specimen of the ventral valve from which the
shell has been removed by weathering. The cast of the spondylium shows it to have been

SYNTROPHIID.

805

of the same type as that of the ventral valve of Syntrophia primordialis (Whitfield) (Pl. CII,

figs. 2, 2a-b) and S. barabwensis (Winchell) (Pl. CII, figs. 1, 1a-d).

The elongate, rounded:

form and scarcely perceptible median sinus serve to distinguish this species from all described

forms.

This is the oldest shell of this type known to me.
of the Cambrian, in the House Range section.
ence, but with the data available it can not well be referred to Billingsella
or any other known genus of the Cambrian Brachiopoda.

FORMATION AND LOCALITY.—Middle Cambrian: (8x) About 2,200 feet (670.6 m.) above
the Lower Cambrian and 2,200 feet (670.6 m.) below the Upper Cambrian, in the limestones
forming 1d of the Marjum limestone [Walcott, 1908f, p. 180], 2.5 miles (4 km.) east of Ante-
lope Springs, in ridge east of Wheeler Amphitheater, House Range [Walcott, 1908f, Pls.
XIII and XV]j, Millard County, Utah.

Genus HUENELLA Walcott.@

Syntrophia Waxcort (in part) [not Hatt and CrarKe], 1905, Proc. U.S. Nat. Mus., vol. 28,
pp. 288-289. (Described and discussed essentially as on p. 798 (under Syntrophia),
but some of the species included in the genus are now referred to Huenella.)

Huenella Waxcort, 1908, Smithsonian Misc. Coll., vol. 58, No. 3, p. 109. (Characterized
and discussed as below as a new genus.)

Huenella Wautcott, 1908, idem, No. 4, Pl. XI, and pp. 142 and 148. (Classification of

Tt occurs 5,525 feet below the summit
IT am not fully satisfied with the generic refer-

FIGURE 74.—Syntrophia? unzia

Walcott. Ventral valve,
the type specimen, from
which the shell has been
entirely removed by weath-
ering (U.S. Nat. Mus. Cat.
No. 52499). From Locality
8x, in the Middie Cambrian,
House Range, Utah. Copied
from Walcott [1908d, Pl]. X,
fig. 10].

genus.)

This genus is proposed to include the more or less plicate species of the Syntrophiide that
have heretofore been referred by me to the genus Syntrophia. They differ from Syntrophia
in having a more or less radially plicate surface and sessile or pseudospondylia instead of free
spondylia supported by a median septum. With the exception of Huenella vermontana and
possibly H. etherrdger, all of the species are from the Upper Cambrian.

The shell structure is fibrous, with many minute pores.

Type.—Syntrophia tecana Walcott [1905a, p. 294].

The generic name is given in recognition of the thorough and valuable work of Dr. Fr. von
Hoyningen-Huene on the ‘‘Silurischen Craniaden.”’

HUENELLA ABNORMIS (Walcott).
Text figure 13, page 299; Plate CIII, figures 2, 2a—m.

Not Camerella calcifera BiruinGs, 1861, Canadian Naturalist, Ist ser., vol. 6, No. 4, p. 318. (Referred in this mono+

graph to Syntrophia calcifera.)
Camerella caleifera Mnnx [not Brriines], 1873, Sixth Ann. Rept. U. S. Geol. and Geog. Survey Terr. (for 1872), p

464 and footnote. (Characterized.)
Syntrophia abnormis Waucott, 1905, Proc. U.S. Nat. Mus., vol. 28, pp. 289-290.
as a new species. )

(Described and discussed as below

The general form varies from transverse (Pl. CIII, fig. 2) to elongate (fig. 2c). Valves
biconvex, with dorsal very convex in some specimens. Hinge line straight. Surface marked
by concentric striz and imbricating lines of growth crossed by fine, rounded, radiating stric
and a variable number of rounded ribs; specimens occur with four ribs in the sinus of the
ventral valve and four on each slope outside the sinus; in other ventral valves only a trace
of ribs can be seen; among the specimens of the dorsal valve there are shells without a sign
of ribs, figure 2d, and nee having from a trace of ribs on the median fold to three ribs on the
fold and traces on the lateral dloynas The largest shell has a length of 7 mm.; width, 9 mm.
There is great variation in the proportion of the length to the width, as shown by the figures

illustrating the species.

a Prior to the definition of the genus Huenella the species now referred to that genus were described under the following genera:

Camerella Shumard [1861, p. 221]. Orthis or Orthisina Etheridge [1905, p. 250].
Camerella Meek [1873, p. 464]. Syntrophia Walcott [1905a, p. 288].

806 CAMBRIAN BRACHIOPODA.

The ventral valve has a broad, strong sinus that depresses the front of the valve; area.
well defined, with a large, open delthyrium. Casts of the interior of the ventral valve show
a well-marked spondylium and very strong main vascular sinuses, figure 2b; both spondylium
and sinuses recall those of Billingsella plicatella (Pl. LXX XVI, figs. 3g, 3]). Sections of the
ventral valve, cut across the umbo, show the spondylium attached to the bottom of the valve.
The flabelliform diductor and adductor muscle scars are clearly shown outside of the vascular
sinuses.

Dorsal valve with an elevated median fold that gives a strong convexity to the valve;
area low, with a strong, open delthyrium; the interior of the valve shows a shallow snovauellfivean
attached to the bottom of the valve posteriorly, and probably supported by a low median septum
toward the front (figs. 21, 2], section fig. 2m) and well-defined anterior and posterior adductor
muscle scars; narrow main vascular sinuses occur (fig. 2h), and slender vascular lines radiate
forward from the muscle sears (fig. 2f).

Observations —This species differs from all riled forms in its variation in outline, con-
vexity, ribs, and internal markings. Some shells approach closely to those of Hwenella texana
(Walcott) (compare figs. 1 and 2 and figs. 1b and 2a, Pl. CII), but each species has a majority
of shells that are quite unlike those of the other. Another point of resemblance is the form of
the spondylium as shown by cross sections. A variety of H. texana from Cold Creek Canyon,
Texas, has some shells that approach those of H. abnormis in the extravagant development of ~
the fold on the dorsal valve and sinus on the ventral valve, but in other respects they differ from
it. The form of spondylium and plications or ribs suggests the genus Parastrophia Hall.

This form was an abnormal representative of the genus Syntrophia, to which it was first
referred, hence the specific name.

FORMATION AND LOCALITY.—Upper Cambrian: (153) Limestone in ravine on west side of Dry Creek, near the
mouth of Pass Creek, about 5 miles (8 km.) north of Hillsdale; and (157 and 158) limestone north of East Gallatin
River, near Hillsdale; both on the Threeforks quadrangle (U. 8. Geol. Survey), Gallatin County, Montana.

(302p) Middle limestone of the Deadwood formation, near the summit of the Owl Creek Mountains, 18 miles (29
km.) southwest of Thermopolis, Fremont County, Wyoming.

Middle Cambrian: (4j) Limestone at the head of Deep Creek, Yellowstone National Park, Canyon quadrangle (U.S.
Geol. Survey), Wyoming.

HUENELLA BILLINGSI (Walcott).

Plate CII, figures 5, 5a-c.
Syntrophia billingsi Watcort, 1905, Proc. U. S. Nat. Mus., vol. 28, pp. 291-292. (Described-and discussed as below

as a new species.)

General form transversely subquadrate; rounded; biconvex, with the dorsal valve elevated
on the median fold. Surface marked by a few imperfectly developed ribs on some shells, while
others have only concentric striz and lines of growth. Ventral valve with a relatively shallow
median sinus, in which obscure, narrow ribs sometimes occur; none of the specimens in the col-
lection show the area, but from the profile of the valve it must have been of moderate height,
with the rather sharp apex curving slightly over it; a single poor cast of the interior shows
the outline of a spondylium much like that of S. primordialis; the evidence of the presence of
a median septum is a dark line in front of the end of the cast of the spondylium, which indicates
that the shell substance extends down into the limestone and that it is the median septum.
Dorsal valve with a small umbo and apex that extend forward into a prominent median fold
that may be plicated (PI. CII, fig. 5c) or smooth; one partly exfoliated shell shows three pica
tions on the fold and three or four on each lateral slope of the valve.

Observations.—This species belongs to the plicate group of the Syntrophiide represented
by Huenella texana (Walcott) and H. abnormis (Walcott). It differs from H. texana in being
less convex and in having a shallower ventral sinus, less prominent dorsal fold, and more obscure
plications.

The specific name was given in honor of Mr. E. Billings.

FORMATION AND LOCALITY.—Middle ? Cambrian: (28a) ‘“‘St. Albans formation,”’ in limestone lentil about 1 mile
(1.6 km.) east of Parker’s quarry, west of Georgia, Franklin County, Vermont.

SYNTROPHIIDA. 807

HUENELLA ETHERIDGEL Walcott.
Plate LX X XIX, figures 9, 9a.

Orthis (or Orthisina) sp. Eta#ERiIpesx, 1905, Trans. Roy. Soc. South Australia, vol. 29, p. 250, Pl. XXV, figs. 9 and 10.
(Described as below and discussed. The specimens represented by figs. 9 and 10 are redrawn in this monograph,
Pl. LXXXIX, figs. 9 and 9a, respectively.)

Huenella etheridge: Waucotr, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, pp. 109-110, Pl. X, figs. 13 and 18a.
(Described and discussed as below, copying the original descriptions. Figs. 13 and 13a are drawn from the
specimens represented by figs. 9 and 10 of the preceding reference and are copied in this monograph, Pl. LX XXIX,
figs. 9a and 9; respectively.)

Doctor Etheridge describes the ventral valve as follows:

Subquadrilateral, convex, the greatest convexity at about midway in the length of the valve, the sinus gradually
deepening and widening toward the front, and bounded laterally by ill-defined folds, one on either side, the surface
sloping away on either side rapidly to the lateral margins, and at a very much less angle within the arlene: there are
indications of coste on the divaricating folds and in the sulcus.

The hinge features are hidden in matrix, nor is the umbo distinctly visible.

’ He describes the dorsal valve as follows:

Rotundato-quadrate, the cardinal margin as long as the width of the valve, the surface convex, except on the
dorso-lateral alations, where it appears to be flattened. There is a central, acute, or pinched-up fold, produced forward,
and expanding as it advances. There are indications of the existence of strong, distinct, subradiating coste.

Whether or no this is the brachial valve of the species represented by the preceding form it is at present impossible
to say; the two occur in the same bed, however.

From the study of the various forms of Huenella described herein, I think that the two
valves belong to one species, and I take pleasure in naming it after Dr. R. Etheridge, jr.

ForMATION AND LOCALITY.—Middle ? Cambrian: (315¢ [Etheridge, 1905, p. 250]) ‘‘Archzeocyathinze white lime-
stone” at Wirrialpa, Flinders Range, South Australia.

HUENELLA LESLEYI Walcott.
Ww

Text figures 75A—C.

Huenella lesleyi Watcott, 1908, Smithsonian Misc. Coll., vol. 53, No. 3, p. 110, Pl. X, figs.12 and 12a. (Characterized
and discussed as below as a new species. Figs. 12 and 12a are copied in this monograph as figs. 75B and 75A,
respectively.)

Only the exterior of the valves of this species is known. In form and outline it is most
nearly related to Huenella texana (Walcott). It differs from the latter in being broader in
proportion to its length, and in having narrow, radiating, rounded ribs over the entire surface.

FIGURE 75.—Huenella lesleyi Walcott. A, A’, Exterior of partly exfoliated dorsal valve (U.S. Nat. Mus. Cat. No.52481b). B, Exterior of ventral
valve, the type specimen (U. S. Nat. Mus. Cat. No. 52481la). C, Exterior of ventral valve (U.S. Nat. Mus. Cat. No. 52481c).

The specimens represented are from Locality 54e in Blacksmith Fork Canyon, Cache County, Utah. Figures 75A and 75B are copied from
Walcott [1908d, Pl. X, figs. 12a and 12, respectively].

This is probably the oldest Huenella. It occurs 1,025 feet (812.4 m.) below the summit of
the Upper Cambrian. Billingsella coloradoensis (Shumard) and Lingulella manticula (White)

occur in the same bed of limestone.
The specific name is given in honor of folk Dr. J. P. Lesley, state geologist of Pennsylvania.
ForMATION AND LOCALITY.—Upper Cambrian: (54e) About 200 feet (61 m.) above the Middle Cambrian and

1,025 feet (212.4 m.) below the top of the Upper Cambrian in limestones forming 3 of the St. Charles formation [Walcott,
1908f, p. 193], in Blacksmith Fork Canyon, about 10 miles (16.1 km.) east of Hyrum, Cache County, Utah.

808 CAMBRIAN BRACHIOPODA.

HUENELLA ORIENTALIS (Walcott).
Plate CIV, figures 3, 3a-b.

Syntrophia orientalis Waucort, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 292. (Characterized and discussed as below as
a new species. )

This species is closely related in form and surface characters to Huenella texana (Walcott)
and some forms of H. abnormis (Walcott). It differs from them in details of surface ribs. On
he dorsal valve there are two or three faintly defined radiating ribs on each side of the median
fold, which has obscure ribs upon it. Corresponding ribs occur upon the mesial depression of the
ventral valve and the side slopes adjoining the depression. The material representing it is too
limited to warrant an identification with any described species. H. orventalis is the trans-
Pacific representative of H. texana.

FoRMATION AND LOCALITY.—Upper Cambrian: (C64) Upper limestone member of the Kiulung group [Black-
welder, 1907a, pp. 37 and 42 (first list of fossils), and fig. 10 (bed 20), p. 38] 2.7 miles (4.3 km.) southwest of Yenchuang,
Sintai district, Shantung, China.

HUENELLA TEXANA (Walcott).

Plate CIII, figures 1, la-i.

Camerella sp.? SHUMARD, 1861, Am. Jour. Sci., 2d ser., vol. 32, p. 221. (Mentioned; see below for copy.)
Syntrophia tecana Waxcort, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 294. (Original mention copied and species dis-
cussed as below as a new species.)

This may be called the plicate representative of the group of species referred to the Syntro-
phiide. It is intimately connected with the smooth forms by a series of shells that vary from
16 ribs on a valve to 1; the extremes are shown by Plate CIII, figures 1d and le. In form
H. texana is much like a abnormis (Walcott); also in the cross section of its spondylium.
They differ in the extravagant development of the plications of H. texana, a feature characteristic
of a large series of specimens.

The average size of the larger shell is width, 8 mm.; length, 6 to 7 mm.

It is probable that this is the shell referred to by Dr. Shumard [1861, p. 221] as Camerella
sp.?. He said of it:

There are several specimens of a small brachiopod in the Texas state collection, from the Potsdam sandstone of
Morgans Creek, Burnet County, which appear to belong to the genus Camerella recently created by Mr. E. Billings.
Unfortunately, however, they consist merely of detached and imperfect valves toomuch weathered for satisfactory
determination and description.

FoRMATION AND LOCALITy.—Upper Cambrian: (68) Interbedded sandstone and limestone, Packsaddle Mountain,
Llano County; (71) limestone in Cold Creek Canyon, Burnet County; and (69) limestone near Honey Creek, Burnet
County; all in Texas. ;

HUENELLA TEXANA La&yruscuLus (Walcott).

Syntrophia texana leviusculus Watcort, 1905, Proc. U. 8. Nat. Mus., vol. 28, pp. 294-295. (Characterized and dis-
cussed as below as a new variety.) :

A variety occurs in Texas with a few traces of plication in the smus; and with one, two,
or three strong plications on the dorsal fold, or none at all; it approaches Huenella ainannis
(Walcott) in some of its extreme forms where the ribs are ‘line on a prominent mesial fold.
In most young shells the sinus and fold are inconspicuous, the convexity is very moderate,
and the shell smooth; nearly all the characters of the adult are missing.

a

SYNTROPHIIDA. 809

A group of young shells from Honey Creek shows only the smooth, slightly convex forms,
with only slight ventral sinus and dorsal fold. One larger shell associated with the young
shells has a relatively deep sinus and a trace of a plication.

FORMATION AND LOCALITY.—Upper Cambrian: (69) Limestone near Honey Creek; and (71) limestone in Cold
Creek Canyon; both in Burnet County, Texas.

HUENELLA VERMONTANA DN. Sp.

Text figure 76.

This species is represented by a single.specimen of the two valves united. It is somewhat
imperfect near the beaks. ;

Valves moderately and about equally convex, with
the dorsal valve subcircular in outline and the ventral
more elongated at the beak. Hinge short; cardinal
angles rounded.

Surface marked by low, concentric ridges of growth
and numerous fine, rounded, radiating ridges that in-
crease in number from the umbo to the margin by
both bifurcation and interpolation of new ridges. A

FIGURE 76.—Huenella vermontana n. sp. A, Ventral
5 > view of a specimen. A’, Dorsal view of same speci-
low, moderately broad sinus occurs on the anterior half men. A”, Side view of the same specimen, showing

: two val ited.
of the ventral valve and a narrow median fold on the ea ;
The specimen is from Locality 319s, near St. Al-

dorsal valve. Where the surface of the shell is exfo- hans, vermont (U.S. Nat. Mus. Cat. No. 58312).
liated the shell appears to be minutely punctate.

The ventral valve has a length of 11 mm.; width,9 mm. The convexity of the two valves
is 6 mm.

Observations.—This shell differs from all known species of Huenella by its finely ribbed
surface. In this respect it recalls Swantonia antiquata (Billings) (Pl. CIV, fig. 5). It occurs
in association with Paradozxides in an intraformational conglomerate.

FoRMATION AND LOCALITY.—Middle Cambrian: (319s) ‘‘St. Albans formation,”’ at St. Albans, Franklin County,
Vermont.
Genus CLARKELLA Walcott. 4

Clarkella Waxcorr, 1908, Smithsonian Misc. Coll., vol. 58, No. 3, pp. 110-111. (Described and discussed as below
as a new genus.) |
Clarkella Waucorr, 1908, idem, vol. 53, No. 4, Pl. XI, and pp. 142 and 148. (Classification of genus.)

General form rotund, unequally biconvex. Surface smooth or marked by concentric striz
and lines of growth. Ventral valve convex at the umbo and with a strong, broad median
sinus; area low and divided by.a relatively large delthyrium. Dorsal valve convex at the
umbo, which is extended forward into a strong, broad median fold. Cross sections of the
valves near the apex and beneath the umbo show a spondylium supported by four or more
septa that divide the umbonal cavity into five chambers.

Thin sections of the shell of the type species show it to be fibrous and with many minute
pores arranged in lines radiating from the beak to the front and side margins of the valves.

Type.—Polytachia? montanensis Walcott.

This genus is known only by the type species from the Lower Ordovician of Montana. It
is distinguished from Polytechia Hall and Clarke [1892c, p. 239] by an open delthyrium, smooth
surface, and presence of septa and spondylium in the dorsal valve. It differs from Syntrophia
and Huenella in having several septa supporting the spondylium, and also from Huenedla in
having a smooth nonplicate surface.

The generic name is given in recognition of the work of Prof. John M. Clarke, of the Geo-
logical Survey of New York, in connection with Prof. James Hall, on the fossil Brachiopoda.

a Prior to the definition of the genus Clarkella the type species was placed under Polytechia [Walcott, 1905a, p. 295].

810 CAMBRIAN BRACHIOPODA.

CLARKELLA MONTANENSIS (Walcott).

Plate CIV, figures 2, 2a-d.
Polyteechia? montanensis Waucotr, 1905, Proc. U. S. Nat. Mus., vol. 28, pp. 295-296. (Characterized and discussed
as below as a new species. )

This shell was placed with Camerella calcifera until sections were made showing the
numerous septa supporting the spondylium and cruralium. In general form it is close to
Syntrophia rotundata Walcott, differing in the numerous supporting septa of the spondylium
which divide the umbonal cavity into five chambers. The material available for study does
not show the area in very good preservation; a delthyrium exists in the area of the ventral
valve, which is all that can ihe said.

This species appears to be a direct descendant of the smooth, convex forms of Syntrophia,
like S. rotundata.

ForMATION AND LOCALITY.—Lower Ordovician: (302j) Limestone on the east side of West Gallatin (Gallatin)
River, above Gallatin, Gallatin County, Montana. :

INDEX.

In this index black-face figures refer to locality numbers, light-face figures refer to pages.

The main refer-

ence to each genus and species (the page reference which is usually put in black-face type under the old scheme
of lumping all references together, or the page reference which will be used in the future synonymy of the genus or

Species) is given first and is invariably preceded by the word “‘

than mentioned on the page given.

described,”

even if the genus or species is little more

- References to the description of certain features of a species or to comparisons with other species are indexed only

if the description or comparison occurs on some other page than the one on which the species is described.
The table of synonymic references, on pages 27-98, may be regarded as a completely cross-referenced index to the
Synonymy in the monograph, as each name in that table is there given in the form in which it appears in the synonymy
of the species to which it is now referred. This index therefore includes only those synonymic references that appear
in connection with the description of the genera and species, all synonyms being placed in quotation marks.
This index gives the numbers of all the localities in any country, province, State, county, district, or place, as

well as the numbers of all the localities identified from the different formations or other stratigraphic units.

These

numbers are tabulated on pages 160-291, where full information is given as to species included, authority for
citation, correlation and comparison with other localities, and the stratigraphic section (pp. 123-159) in which the
locality is placed or with which it is correlated. For these reasons this index includes no reference to the localities

given in connection with the description of the species.

The names of species given under the heading “‘Locali-

ties,’’ on pages 160-291, are not indexed as appearing on those pages, but the page on which each brachiopod there
named is described appears in the index, and on this page are given not only the numbers but detailed descriptions

of all localities from which the species has been identified.

Geographic names that have been passed on by the United States Geographic Board are spelled in accordance
with that board’s decisions, but a few variant familiar spellings have been inserted in the index with cross references.

Abe Lincoln mine, near Pioche, Nevada, locality at.............. 333
Abington quadrangle, Massachusetts, locality in............-.-.. 326b
Ableman, Wisconsin, locality at...................---.----------- 328q
abnormis, see Huenclia.
Abrigo limestone (Middle Cambrian), locality in-............---- 14x
Acadian, generalized section of, listing species and localities. .... 132-133
acadicus, see Obolus.
Acerocare zone, in generalized section for Sweden, Denmark, Fin-
land, and Norway, listing species and localities .........-. 145
IGEN IY ital 3 Ssecasconascas en snoeanesebososeUsoouade=ccensS 309e
Xcknowledsimentse asaeeleeee ase eaee eceie eee cee eee 11
(Acritis), see Obolus (Acritis).
tAcrothele descriped ane satire nee eee eee eee eee eieeee cen 630
cardinal area discussed .......-.---.-.-----------+----- 305
Classifica tioniOfens= seen s= sae ae --- 321,324
compared with Acrothele (Redlichella)........-.--.- 662, 663

A NGOER bs Sate oaba ac anoedenc ass Sasa snese cos
Acrotreta and Acrothyra .-..
Acrotreta definita........---

Acrotreta gemmula....... -

Botsfordia=22. 5-2 teases see ee eee
Discinopsis qulielmt.-..-.--.-.-.-----.---------
“ Tinnarssonia””

Schizopholspeeree eee ae eee sos 608, 609
POTKIds een se eth say he eel tern ete ciate Se shai 611
development of....-....-.-.--.------ 314
distortion of shells of 654
evolution discussed....-.-.--- 319
evolution of 317
general geographic and stratigraphic distribution of the
species referred to...........-----+---+------+-------- 105
general stratigraphic distribution and number of Cam-
\ brian species and varieties of.............--.-------- 111
mentioned
number of Ordovician species and varieties of .... ...- 113
number of species of, in the different types of sedi-
TWANG -oasacnanasscagadd ssOboSHAGabeSODeRATOCSOSNSS 160

Acrothele—Continued.

pedicle tube discussed.......-.. Ce ayer rekers yrs tare a Pace 314
reference to, of Acrothele nitida discussed .......------ 651
reference to, of Acrothele pretiosa discussed -.....-...- 705
reference to, of Acrotreta inchoans discussed ....-...... 690
reference to, of Acrotreta ? minima discussed .-.-..-.--- 695
species of, grouped under surface characters .......- 632-633
surface ornamentation discussed.........-..-..-.-.- 301, 302
type species Acrothele coriacea........-..-.-----.----- 632
vascular markings discussed.......-...-.-..---------- 311
“abavid Za GISCUISSEd = seen st aa pee tee ee ee eee ee 635
‘artemis described seca cases esa ae eee 634
general geographic and stratigraphic distribution tabu-
Verte diets seer ie ate ice cee choo eae Sra Oe ECs Core 105
type specimen figured -.........-..-.--.-.- text fig. 54,634
avia, describedeeaceee eee eee eee eee 634
compared with Acrothele avia puteis. - 636
PAICTOLILELELDTOLES eee tae ee eee eee 654, 655
general geographic and stratigraphic distribution tabu-
A Hex bes Aa a Ma ae A re ree Se ee 105
in group based on surface characteristics..........-..- 632
surface ornamentation discussed 302
type specimen figured.........-.- .. Pl. LXI, fig. 7a
Gna putes sdescElbedar eee aesesere eee eee e a aace see aeee 636
general geographic and stratigraphic distribution
Tab ulated eee aes te teers a tae eee ae Sei vaiee aa rcieerste 105
in group based on surface characteristics..........---- 632
type specimen not figured.
“barbata,”’ described and discussed......-.-...-.----------- 640
bellagumnctaer described a-ereesnee nea seen eee a 636
compared with Botsfordia pulchra. . 633
Micromitra (Iphidella) pannulaz......-...------- 633

general geographic and stratigraphic distribution

tabulatedtenasa-ccenca soe sen ate Saeco s See cie cise
stratigraphic position mentioned.
surface ornamentation discussed...
type specimen figured................-...--

811

812

Acrothele bellula, described ......--------------------------------- 637
cardinal area discussed.....-..----------------------- 305
compared with Acrotreta definita.-..........---------- 631
discussed 631
general geographic and stratigraphic distribution

Hiplwesel ness shssenseosoteconssasepesssseezcecesss 105
pedicle tube discussed......-------------------------- 314
SUTIACe CISCUSSCO sess ene eee eee eee
type specimen figured

bergeroni, described...--.---- PABA aneeeEATOoSeaRt fosaees
compared with Acrothele coriacea...-...-------------- 643
Botsfordia ? barrandei 603
GHACDESE GL. Coe se Ssecescseesesssceccesezeosensseseces 633
general geographie and stratigraphic distribution

DWI EWC. ee wee sbascm ssc ceo sor sseeecedseceezceses 105
in group based on surface characteristics. -........-..- 632
type specimen figured Pl. LVIII, fig. 6c

bohemica, described.......---.--.--------------------------- 639
compared with Acrothele bergeroni........------------ 638
PACT OLILELELCONt (LCE (pee ee ee ae 643
Acrothele quadrilineata....-..-.----------------- 655
general geographic and stratigraphic distribution
UDI ENAOL en cce aces spoons soso sereosstaseSeace=ses 105
in group based on surface characteristics.
type specimen figured.....-...---..-----.--

borgholmensis, described...-..-.----------------------------
compared with Acrothele ceratopygarum

PACT OLNELE LU TLET ete = ee ee

general geographic and stratigraphic distribution

HVC ~ 2 sesscesoc cos tere PssscaeFs5sSs0S2252 105

in group based on surface characteristics...........--- 632

type specimen figured.-.-.-...----- Pl. LXIII, figs. 2 and 2a
ceratopygarum, described. ......-.-------------------------- 640
compared with Acrotreta seebachi.......--------- 2 7

GUISCHISSC Case eee eee 634

general geographic and stratigraphic distribution

1 UB WIEN 6-5 5so52scessoacaecosoesesceseeeseo S555 105

in group based on surface characteristics..-.--.....--- 632

type specimen figured........-... Pl. LXIII, figs. 1 and la
colleni, described.......------------------------------------- 640

compared with Acrothele panderi.....--.---- 651

Micromitra (Paterina) wapta...---------------- 357
general geographic and stratigraphic distribution tabu-

IGG oe cescccoocee ssbarsarnesorenstosessseiecesdeos 105
in group based on surface characteristics. ........----- 632
type specimen figured........---..------- Pl. LXIII, fig. 6

coriacea, described..-..--.---------------------------------- 642
compared with “‘ Acrothele barbata”’ -- 640
Acrothele bergeroni-..---------- 638
Acrothele bohemica- ae 039)
Alene GUNG: a5 205220 20cs sess cesseccssee 641
Acrothele intermedia... ...---.------------------- 646
Acrothele levisensis 646
Acrothele matthewi 648
Acrothele panderi.-..-------- 651
Acrothele quadrilineata.....--------------------- 655
VA\CTOLELE)SWLUSTQ1U Yess eee = ee 658
Acrothele (Redlichella) 662
Acrothele (Redlichella) granulata......---------- 663
Botsfordia granulata....----.-------.----------- 606
general geographic and stratigraphic distribution tab-

EC ee Ce ee 105
in group based on surface characteristics. -....-------- 632
surface ornamentation discussed... .---------------- 302, 632
type of Acrothele.....-.------------------------------ 632
type specimen not figured.

decipiens, described... .----------------------------+------- 644
general.geographic and stratigraphic distribution tab-

105

in group based on surface characteristics. -------.-.--- 632

stratigraphic position mentioned. ---...-.------------- 318

type specimen figured..-.-.------------- Pl. LVI, fig. 3a

dichotoma, described ...-..---------------------------------- 644
general geographic and stratigraphic distribution tab-

(bin RSs ideas = santos aoeShepeeasines ToS aes eae 105
in group based on surface characteristics 633

type specimen figured.....--.--------------- Pl. LX, fig. 2

CAMBRIAN: BRACHIOPODA.

Acrothele gamagei, described ..-----------------.----2- =. -------- 645
general geographic and stratigraphic distribution tab-
ulated... -- EE aS CREA ecae ae med ap sedauce 105
in group based on surface characteristics.....-...-.--- 632
type specimen not figured.

granulata, type of Acrothele (Redlichella)
“ef. granulata Matthew,” discussed... ..----
intermedia, described

general geographic and stratigraphic distribution tab-

WEN eo soot cosdadeeedesbs sspootecck onto toonesegces 105
in group based on surface characteristics-..--...--.--. 632
type specimen figured.......-..-. Pl. LVI, figs. 3 and 3a
LEVISETISTSACESCUDC Cerne n= sete ne see eee eee 646
general geographic and stratigraphic distribution tab-
WENO. cagoeacece= +: cos sre soncosse ss caSsocsesseSo 105
in group based on surface characteristics. .......-.--- 632
type specimen figured Pl. LXXXI, fig. 12
maculata, described.......-.--------------- . 647
compared with Acrothele villaboimensis . 660
general geographic and stratigraphic distribution tab-
WIG easedcnsasoseasdsbeonefoseebancssaeseussaes 105
in group based on surface characteristics 632
type specimen figured Pl. LVII, fig. 2b
matthewi, described...-..-------- 647
compared with Acrothele avia.. 635
Acrothele avia puteis.-...- 636
VAICTOLNELEICOTIRCCOME Ene eee ee eee me eee en 643
PAICTOLNELENC ECL DIET See eee ee es 644
PAICy OF ELEXG OTL CL ela ee eee 645
Acrothele matthewi multicostata......-..-------- 650
PACT OLELEMI IG 0a eee eee ee eee een 651
Accrothele pretiosa....-.------------------------- 652
PACT ORILEL EAD 2TTUL a ae ee 653
Acrothele prima costata....--.------------------ 653
Acrothele subsidua........---------------------- 658
Acrothele yorkensis 661
Acrothele (Redlichella) granulata.......-.-.-.--- 632
Botsfordia cxlata......----.--------------------- 632,
Botsfordia granulata.... 632
general geographic and stratigraphic distribution tabu-
LEGA Bae a ee eeenanaeALAadsaeauenpedcedoDEes 105
in group based on surface characteristics...........-.. 682
SUrfacelGiSCusSe Ge — 2st a== a seem ee a 632, 633
type specimen figured . Pl. LXI, fig. la
‘varieties Giscussed) «<< oo = on soe ene ee en 649
“‘matthewi costata” discussed. ....-------------------------- 649
matthewi eryx, described 649
compared with Acrothele coriacea 643
Acrothele matthewi......----------------------+- . 649
general geographic and stratigraphic distribution tabu-
TEI bose sec Sada randdsssesseGeccuesdosssencsoeccs 105
in group based on surface characteristics. ....-.--..--- 632
type specimen figured ...........-...------- Pl. LXI, fig. 2
matthewi lata, described.........--------------------------- 649
discussed 649
general geographic and stratigraphic distribution tabu-
MEI poe enocanceeeseséacscaness Joesseedescacs 105
in group based on surface characteristics 632
type specimen figured..............--..----- Pl. LXI, fig. 3
matthewi muilticostata, described.....-.--------------------- 650
compared with Acrothele matthewi.....--.--.--------- 648
Acrothele prima costata........--.-------------- 654
649
105
in group based on surface characteristics...-....-.-..- 632:
surface ornamentation discussed.......-....-.-------- 302
type specimen not figured.
“<matthewi prima,” discussed 649
2 minuta, described..-...---------- 650
general geographic and stratigraphic distribution tabu-
TE GT Soesacis son emoaso cere Sue kseootansecneesabesaas 105
in group based on surface characteristics... ...-- 632
type specimen figured ...-...------------- Pl. LXIII, fig. 3
nitida, described.......-...--------------------------------- 650°
general geographic and stratigraphic distribution tabu-
IER =\s ae Se RS RB Asad ee saeco sSocs Ss apesroAS 105
in group based on surface characteristics --- 632
type specimen figured...-...-.--.--------- Ill, fig. 4

INDEX.

ALGONA MED UGIg CESO AMONG Coos ses ances ssnnsesceaseoscossooss 651
general geographic and stratigraphic distribution tabu-
lated ah sa. Shale Soe bcoray tee tesogen ne saeeae see 105
in group based on surface characteristics...........--- 632
type specimen figured Pl. LIX, fig. 5
pretiosa, described... ---2=-5.------- 652
general geographic and stratigraphic distribution
ta pWlatede. coho ssk es coe eee eco eeeneee 105
in group based on surface characteristics. ......--..--- 632
stratigraphic position of beds containing, discussed... 705
type specimen not figured.
MriMoNGescriped == 2 -hie2 -- Sees cose See ee one tees 653
compared with Acrothele avia-. 636
Acrothele bohemica......... 639
Acrothele prima costata.... 653
Acrothele proles. 655
general geographic and stratigraphie distribution
tabulatediye << c8 2. See ee vnc ane cinaeeeye eee 105
in group based on surface characteristics......-..---- 632
Surface discussed esen.- ereer seca eae ee eee eee ee 633
type specimen figured. ..-. Pl. LX, fig. 6
prima costata, described ..-.......-.------ eee) = 653)
compared with A crothele artemis... -- 634
PAIcrotele DONE ICO sas = 2 eee see eee 639
Acrothele matthewi multicostata 650
Acrathele prima 652
general geographic and stratigraphic distribution
tabwlatedeee es s=s—- a= | CS EBRBRL Baba scanBADeHCoecS 105
in group based on surface characteristics ......-.-.--- 632
surface ornamentation discussed........-.--------- 302, 633
type specimen not figured.
DYIMVINACSCHIPC Cee en ee eae a eee a ee aenee ese eeeeceee 654
general geographic and stratigraphic distribution
tab Wlated sei: tose sti 1 ss ome 4, See atone 105
in group based on surface characteristics. . 633,
type specimen figured . Pl. LVII, fig. 6
PPTOLES HCESCHIDEM esha isso ences eet sce scene eee eee 654
compared with A crothele avia : 636
Acrothele matthewi 648
general geographic and stratigraphic distribution
UBIO UID Gh. Hod aetasenbessomess~ -seasnopensabecnnaden 105
in group based on surface characteristics...........--- 632
type specimen figured. -.----.--8.--2----22 Pl. LXILI, fig. 4
quadrilineata, described 685
compared with A crothele bergeroni 638
*Alcrotiele|coTiaced a= an aoe = aes a 643
Acrothele primzva 654
general geographic and stratigraphic distribution
tabulateds.e tec s ass. case scta = ee oie 105
in group based on surface characteristics ........-.... 632
type specimen figured...............-.-.... Pl. LVII, fig. 5
tara, described 655
general geographic and stratigraphic distribution
tap wlatedewecno see cette -ceeee eee eee eee 105
in group based on surface characteristics. ..........-- 633
type specimen figured................-..-

SPU TTt GES CHIDE Cente eee ele eee
compared with Acrothele subsidua .
Acrothele subsidua hera....--

general geographic and stratigraphic distribution

HUI ENOL. «3s cosccoosscoszoeesesosnts:seoessebes 105
in group based on surface characteristics..-.......... 632
type specimen figured................. Pl. LX, fig. 3

Syn, COMO NOL - - soo c oat oars oocoaeoacanso[s sonssoese 656
compared with Acrothele dichotoma - 645

PAICr OCH ELE UTC ULL = an menial minnie an = = ee) i=l 647

Acrothele rara 655

Alcrothele spurrt.._-.-------.-- PeooG)

Acrothele subsidua hera....-.-. -- 659

Acrothele subsidua lzvis. - 659

PAlcrotele bin Ment saree tantate ate eae ein lata= Se aiee 660

Acrotreta sagittalis taconica
general geographic and stratigraphic distribution tab-

in group based on surface characteristics........--..--
surface ornamentation discussed...........--.----.---
type specimen figured...............--.....- Pl. UX, fig. 1

Acrothele subsidua hera, described ...........-.---.--------------- 659
general geographic and stratigraphic distribution tab-

Ulatedie so, Clee pce ewer eee atie sas cossaece 105

in group based on surface characteristics. .-............ 632

type specimen figured...........-.-..- Pl. LX, fig. 9

subsidua lxvis, described......---...----- pes) 659

compared with Acrothele subsidua- - - 658

general geographic and stratigraphic distribution tab-
Tlated he Ace et Sac ae eemerete mie ete erste icss = 2 105

in group based on surface characteristics. ............ 632
type specimen not figured.
tunmert, \AeScribed ase ae sa- eae eee eee eee eee e eee 660

general geographic and stratigraphic distribution tab-
Wlateds he she Se eee eee eC eee eee caisciaae 105

in group based on surface characteristics. 632
typejspecimentifriined] = s=seee eee eeeneeeeee Pl. LX, fig. 7
COPANO MARTE, CONCH NVC! — - secs secesscossceseeessecncece 660

general geographic and stratigraphic distribution tab-

in group based on surface characteristics 633
type specimen not figured.

woodworthi, described. -.......--...-- Aue ase ee ceweneas 661
compared with Acrothele spurri. 656

general geographic and stratigraphic distribution tah-

in group hased on surface characteristics. ............ 632

stratigraphic position mentioned...-................. 318

type specimen figured............. Pl. LX, fig. 6

yorkensis, described.........-.--.------------- = ail

compared with Acrothele sp. undt. a 662
general geographic and stratigraphic distribution tab-

Watedis Assess seh sae core Desseoraeco 105

in group based on surface characteristics. = 632

type specimen figured , Pl. LIX, fig. 4

So Win hi, ), Cosel] oa onsossosbossasseeasetoseseancsesease 662
general geographic and stratigraphic distribution tab-

ulated 105

633

type specimen figured Pl. LXIII, fig. 5

sp. undt. Moberg, described 662

general geographic and stratigraphic distribution tab-

mlatedis 25.22 228i sgse shat eae ee eee

in group based on surface characteristics.

Acrothele (Redlichella), described
cardinal area discussed
classification of. ....

evolution of

general geographic and stratigraphic distribution of the

SMES MEN AMEG! (1. .-5ss05ssacgoseeseetossecsacesos 105
general stratigraphic distribution and number of

Cambrian species and varieties of................... 111
intermediate between Botsfordia and Acrothele........ 663
number of species of, in different types of sediment... 160

type species ‘‘ Acrothele granulata”’............-.... 632, 663
granuwlata, described: --------------------------
compared with A crothele bellapunctata.. .
PIGROPUMO TN NTE om oceacomccasscocsssedsenes
PAlCTOLRELEICOmOCCO MEP Ee eee nena ee ee eee

Acrothele intermedia.

Acrothele matthewi...............----

Acrothele panderi. -

A crothele mang ss tas eee eecene tse ceciencs cee ne

A crothele yorkensis. c
Botsfordia granulata.............-- aay OY
general geographic and stratigraphic distribution

tabulated acest pe eee seme ee ein ie seen 105
intermediate between Acrothele coriacea and Botsfordia

(GRU DON en Baa oboe eaeaeaocne dace Soc aL OT ae pease 663
surface of, confused with that of Acrotreta socialis_.._. 712
surface ornamentation discussed.........-........-.-- 302

type specimen not figured.
NerothelinseyclassiticatlonsOlaeeeseee eee eee eee eee eee eco 321,324

genera and species referred to, described .- - 630-665
Acrothyna; describedeeser a= se. sae aes neces eceane eae 715
cardinal area discussed .-....-..-- ASuSosaecHOSSCORpS 305
classification of. 321,324

compared with Acrothele and Acrotreta.............-- 313

ZALCHOUN EL en CON CELULL = anes a eee eee ee eee 679

ID ISCURODSISE ew ene eee ele ra ae aon cle eee 721

814

Acrothyra—Continued.

@volution GiSCUSSCd. === = 2 o-oo eee ence ee meee 319
CRMAOTUHO Ois oo sscec scene oceossesoscgeotassosesee2205 317

general geographic and stratigraphic distribution ofthe
species referred to. ...-.-----.---------------------- 106

general stratigraphic distribution and number of
Cambrian species and varieties of..-....---.---.--- 111
number of species of in different types ofsediment.... 160
pedicle tube discussed.....-------......-------------- 314

position assumed by shells in settling to the bottom
GHACUESOC Se 2 ssbcns secs Sosc Sot cbonsodesesscsosa0s2 716
reference to, of Acrothyra minor discussed. -.--.------ 717
reference to, of Acrotreta inflata discussed........----- 691
reference to, of some of Matley’s species discussed... . 703
surface ornamentation discussed.-.......--.-------- 301, 302
type species ‘‘Acrotreta proavia”’......----------- = Hike
vascular markings discussed. a aval
minor, described. ...-----------------+---+++++22222222----- 717

general geographic and stratigraphic distribution
TAO. - son ee ssosseseesds= Sans soesasneesosss5 106
type specimen figured -....-...--------- Pl. LXXVI, fig. 4
proavia, described.......------------ 717
compared with Acrothyra signata....------.---------- 719
Acrothyra signata orta....---.------------------- 719

. general geographic and stratigraphic distribution
(OMIENOL. Host oosndo.sesnnecoseSsscrseeosasuesecep 106

position assumed by shells in settling to the bottom
GISCUSSEG cose see se sense ee ee oe ie l= 716

type specimen not figured.

varieties discussed......------------------------------ 716
“proavia crossa,”’ discussed.....-.----------+-------- 717
“proavia prim,” discussed . ....-------------------- 717
sera, described 718
compared with A crothyra signata prima...------------ 720

general geographic and stratigraphic distribution
tabulated ....--..--.-----------------------------=- 106
species and varicties referred to, discussed 716

type specimen not figured.

signata, described . -..----------------------+-+++202----++-- 719
compared with Acrothyra proavia 718
TACT OBNY TO SCN O=\s= ee ea == 718
Acrothyra signata orta....---.---- 719
Acrothyra signata prima 720

general geographic and stratigraphie distribution
(iD MEIC. - S55 sl ses see dances esssosscssossassaeneS 106
type specimen figured. ------------------ Pl. LXXX, fig. 1
varieties discussed. -. 716
signata orta, described 719

general geographic and stratigraphic distribution
HOWE = ano coccnee pe osc ose: peso aaecuRsacesecoa5 106

type specimen figured

signata prima, described 720
general geographic and stratigraphic distribution
Falbul ated Sees ee see eee eae eee eee 106
type specimen figured.......-.----------- Pl. LXXX, fig. 2
“signata sera,’ compared with ‘‘Acrotreta papillata”....---- 716
reference to Acrothyra sera discussed..-..----------- 716, 718
“ signata tarda,”’ reference to Acrothyra sera discussed. . -.- 716, 718
Acrotreta, described . . .....---------------------++-222 22-222 22227 671
cardinal area discussed 305
Classification Olss= see e eee see a sea eee 321, 324
compared with Acrothele..--.--.--------------- 314, 631, 633
Acrothele and Acrothyra.....------------------- 313
Acrothele decipiens... .--- 644
Acrothele matthewi..--.------ 648
Acrothele (Redlichella) granulata. 712
FACTORY) eee eer 716
Botsfordia....--------- 602
Diccllomus...--------- 312, 572
Discinolepis granulata 664
FEA MCROMAM = = seca nedeecbs Sebo osossececc£ ces 665
Linnarssonella minutia. z 668
(QUGIBU. 5-63 5e5= eocspessee jaGewenaceess05 611
Schizopholis......-------------- ae ers 314, 602, 608
evolution discussed - . - 319
evolution of 317
general geographic and stratigraphic distribution of
the species referred to_...-..--------------------- 105-106
general stratigraphic distribution and number of Cam-
brian species and varieties of.....----.------------- 111

CAMBRIAN BRACHIOPODA.

Acrotreta—Continued.

geographic and stratigraphic distribution discussed .. 674
mentioned _ 812, 527, 686, 687, 715
SMUTISCLO}SCANSIGISCTISS Cee sete ets ee eae 312
number of Ordovician species and varieties of-.....-. 113
number of species of, in different types of sediment.. 160

Oldest ispeciesos seer eee eee eee eee eee ree 701
only species from upper Mississippi Valley..........- 711
Medicle umbeldiscrisce lessee eee aaa 314
position assumed by shells in settling to the bottom
GISCUSSE GB SEK eines sean ni ss nae a ere a eter 716
reference to, of Acrotreta inchoans discussed - 690
reference to, of Acrotreta inflata discussed -.......-.... 691
reference to, of some of Matley’s species discussed .... 703
surface ornamentation discussed..........-..-.- 301, 302, 674
type species Acrotreta subconica 673
argenta, described. .....-.-.-------- . 674
compared with Obolella.........:-.:.-.--.------..---- 673
ObOluS Secees kako os sacra is Scab sc SCShSbEBS 673
general geographic and stratigraphic distribution
tabulated. -.2-.-...--

muscle scars discussed...
type specimen figured..........-.--.---
attenuata, described

compared with Acrotreta definita.....-..-- 683
Acrotreta gemma......-- 5 685
Acrotreta idahoensis alta.....-.------ 689

Alcrotneta Kutorgat. ~~. 22-22-2222 2 3 692

Acrotreta microscopica Missouriensis...- 694
Acrotreta ophirensis.....-....-------- 697
PNGORETM DICE 9 soap eocssescsseescassse80 700, 701
false area in, discussed.........-.-.-.---------------- 674
general geographic and stratigraphic distribution
tabulated Jokes «> <cemm jem cien dace see een eee 105
position assumed by shells in settling to the bottom
discussedtioee. . ‘nett eee nee- see eee eee ee eames 716
type specimen figured...........-.-- eeees Pl. LXIV, fig. 1
QHETUNLO VAl.9,) CCSCEID Ceram eee eee ee eee 676
general geographic and stratigraphic distribution
tabulatedeee. a8... sen see nee eee eeeaeee ne 105
type specimen figured..........-..-----.--- Pl. LXV, fig. 2
babel; described- ger --tee ace -is-e ct aemische eerste aeeeece 676
general geographic and stratigraphic distribution tab-
ulated: Ark - |; Braces tas ee ee eee areata 105
type specimen figured.........- Pl. LX XVII, figs. 6 and 6a
barleyy tes cribed ee = eee ee eases eee eee e eee 676
GIR@HRNHG| . - SS ~ sodsocccse cosh soos ecsoroses: socsoors 673
general geographic and stratigraphic distribution tab-
UNCC - ARE codcancs. esac essebeorescccdaspososacesas 105
type specimen figured...........-.-...- Pl. LXXVII, fig. 2
bellarulonceSciib ¢ deer ss a: a ee ee ares 677
general geographic and stratigraphic distribution tab-
WIE WOGIERe ~ «cee ees se oneobose ocsconcetesoesseterse 105
type specimen figured..-........--.-- Pl. LX XVIII, fig. 4
ihn, Gleason ole! 2-5-2 oe = sce tcecl ec acesszeosecsscesessossce 678
general geographic and statigraphic distribution tab-
qilated -/ Sepp sn ees eee eens 105
type specimen figured Pl. LX XVII, fig. 8
bisecta, described 678
compared with Acrotreta kutorgai......--..-.-------- 692
Acrotreta sabrin® ......---- 703
Obolus ( Westonia) ella 674
general geographic and stratigraphic distribution tab-
WEG! 2 -o-cs2o52setes reser estorosesootossaesosces 105
type specimen not figured.
Re COMCELLGLO ACS CLD GCs ee eee ear eee eee eee ets 679
general geographic and stratigraphic distribution tab-
WIG og nsceacy senses Seeestensssessssorosensesess 105
surface ornamentation discussed -...--.-.---------- 302, 672
type specimen figured - Pl. LX XIX, fig. 5
carinata, described 679
compared with Acrotreta circularis....----..--------- 680
general geographic and stratigraphic distribution tab-
CUENTA es ee Sceca coms dboscosoheeesstedsbeaa sc 105
type specimen figured - .-. text figs. 56A—C, 680
CUTCULATIS) | CESCTID EO sees eas sae eee eee ee ee 680
compared with Acrotreta carinata...--..--.---.------- 680
general geographic and stratigraphic distribution tab-
TUR speek seo ador aes bee aoe sesasaseeassacese se 105
type specimen figured .--.....-------- text figs. 57A—D, 680

INDEX.

Acrotreta claytoni, described......-.----------------------+-------- 680
general geographic and stratigraphic distribution tab-
EHEC) oS Geccacossbos ssonacasooHoCesSoeccos pecocses 0b
surface features mentioned
type specimen figured ...-.-..-.-.--..-.
concenitrica, described -.------------------------=------=---
general geographic and stratigraphic distribution tab-
{HEH So so -asscosaesvauaasossuaesecceceesaassodsas 105
type specimen figured - Pl. LXXVIL, fig. 1
conula, described. jose | esi!
general geographic and stratigraphic distribution tab-
WHC! SoS as acochepempSoaaucasssosecasessosesbobe 106
type specimen figured ...........-..-..- Pl. LXXYV, fig. 2b
convera, described 682
compared with Acrotreta gemmula 686
general geographic and stratigraphic distribution
(Do IENIGLS aasevenseeerauedooaneoannesachoanSanaon so 106
type specimen figured ................-.--- Pl. LXVI, fig. 6
«? costata,”” discussed 674
(eayrOett, CALORIC 5 36 eos ncoo sce a enaosabesc CeeenaecenoraeK 682
cardinal area discussed. ...........-.+-.------------0- 305
compared with Acrotreta idahoensis.......--.-..------ 688
PACT OUNELOMITIICNOSCOP ICM aetna eee teyatiniete =tarala tal 693
PACT OUNELOAO DIV CTLS1S =e eee etisalat 697
Acrotreta sagittalis transversa......-.------------ 673
PAICT ON CLONIUUTLCIL Lee eee eee es 714
general geographic and stratigraphic distribution
bata bed eee eee eee 106
type specimen figured... Pl. LXVIII, fig. la
(apni, Ces@n eG - - so osscastesscesncbos asedeedeseerecose09 683
eardinalareal discussed == ps snem se cee eee element 305
compared with A crotreta bellatula...-....-...-------- 678
PAlCTOLELE DELILE same eee eee er 631, 637
A crotreta rudis 702
general geographic and stratigraphic distribution
abulated ceee cence sate eee eee samt ae enema 106
type specimen figured. --- Pl. Lxxty, fig. 2c
depressa, described .....----.-- 683
compared with A crotreta definita - . 683
AA GROMGHTE TUS es 025 25055-0008 292 aSe0ecaz OSES 702
general geographic and stratigraphic distribution
HOw SoconcesanonctanveczecsaseoaacsespESceKS 106
type specimen figured...-..----...----.--- Pl. LXVI, fig. 8
eggegrundensis, described ---...--...-.----------..---------- 684
general geographic and stratigraphic distribution
(HAO WIRCCL oe 5 coo oesceooeesescooreeodsessseses 106
stratigraphic position of bowlder containing........ 454, 864
type specimen figured .....--.---...--- Pl. LXX, figs. 2a-c
CMMOTISTAG CSCIIDE eee eee eee eee eee ee ee 684
general geographic and stratigraphic distribution
tabulated 106
stratigraphic position mentioned - - - 318
type specimen figured... .-.----..---------- Pl. LXV, fig. 6
Cert, Cleo YEO = oo oso sacasccoceoaobcess soscesasscacooas 685

compared with Acrotreta depressa.

AV GOIGIO CUM s coce43524000=c52>-200 so0SmaSDEe 699
Acrotreta schmalenseéi.....-.--.---.------------ 709
discussed 673
general geographic and stratigraphic distribution
(DOE o CecosocadoosssoanusgosnSsop ssesssasoncos 106
TMEMUIOMEM oe ee ao a ow nn nn 675, 691
species referred to mentioned.........--.----------- 673, 689
type specimen figured ...--... - Pl. LXVI, fig. 1
Gemma, Cescribe dle == =e = alee ee om ial lallm 686
compared with Acrothyra proavia....--.---.---.------ 717
Obolus ( Westonia) ella...:......--.------------- 674
general geographic and stratigraphic distribution
WMI. - seco cease cece cosesaneesossescotseass 106
type specimen figured. - . Pl. LXVI, fig. 3a
gracia, described ..--..------------------------------------- 687
general geographic and stratigraphic distribution
HTB ee camo nse ssoees cases scmosseoscoss 106
type specimen figured...........--------- Pl. LXVI, fig. 5a
« 2gulielmi,” type of Discinopsis. - 720
idahoensis, described....-...---.---=-----------++++-2-0+---- 687
compared with Acrothele subsidua 633
Acrotreta argenta....--.--------------- 674
Acrotreta curvata. . - 682
Acrotretd Cefinitd... 2-20-0002 202cnceeeeeneeeeee 683

Acrotreta idahoensis—Continued.

type specimen figured...-...............-.

ATCH OCS AG CSCLULC Oates eee et ee
general geographic and stratigraphic

HA MBIEC - osoecsocessnose onze posenerosseocsoasean

type specimen figured... .-

Dia flatoer eS COLD e Cae eee ee eer

815

compared with Acrotreta eggegrundensis ..--0+----++-------+ 648
Acrotreta emmonsi. 684
Acrotreta cf. idahoensis.. 688
Acrotreta idahoensis alta... 689
Acrotreta marjwmensis......-------------------- 693
Acrotreta Microscopica 693
Acrotreta microscopica tetonensis....-.---------- 694
VAICT OUT LOC UO CIS 1S eee ee eal 696
Acrotreta pyxidicula 701
Acrotreta signalis . veal
Acrotreta spinosa. 713
falseyareavineiGisCUSSedss-se ee eee eee een EheeEE eee 674
general geographic and stratigraphic distribution tab-
ulated (asso facet ce Vee Nace Ease eee emisae 106
position assumed by shells in settling to the bottom
@iscussed... <2 e225. ssa ec cc esas see saaee seer aR eee 716
stratigraphic distribution mentioned 674
type specimen figured..............-.-.-- Pl. LXV, fig. 1b
ch. idahoensis, described: = += 2-2-2 2222s. ee ee === 688
general geographic and stratigraphic distribution
tabulated es sales vate aera eto nie oiie ise ete oe 106
idahoensis alta, described 689
compared with A crotreta attenuata... 675
Acrotreta depressa...-..----- 683, 684
PALCTOLT ELA GEMM Geren ia == a= a re 685
Acrotreta idahoensis sulcata..........----------- 690
VAlcrotnctanpOcifi Ciena eee aa ee ae 699
general geographic and stratigraphic distribution
tabulatedeeeee see eetree a= oe oe eee aan ae eee 106
stratigraphic distribution mentioned .-...............- 674
type specimen figured..-......-...-. . Pl. LXV, fig. 4a
idahoensis sulcata, described ......:...---.------------------ 690
compared with Acrotreta lisani...........------------ 693
PAIR OU ELON DLO NALCO eee eee eee eee eae 714
general geographic and stratigraphic distribution
fabulaied sesseeeee eer eee eae e reese ae eee 106

690

compared with Acrothyra minor......-.-...-..--.---- 717
Obolus ( Westonia) ella ne GEE
general geographic and stratigraphic distribution
{iD NMIPNCC oo scosseacessccasscorsesssosee¢ nposSssas 106
type specimen figured.......--.....--.-- Pl. LX XVI, fig. 2
“inflata ovalis,”’ discussed ..--...------------------- sana, Ge)il
utongats described. seen. n= ee e : 692
Cardinallancay is cussed er eer ee ere Eee ee eel eeeae 305
compared with Acrothele bellula.--.-.-.--------------- 637
Acrotreta attenuata 522 675:
Alenotneta CONCENIN CH. =. 2a = a ale ae = ee 681
Acrotreta eggegrundensis......-.---------------- 684
Acrotreta sagittalis transversa. - bs 673
CE HGlibwan GSGESSHC ooo pecosedesesseess0e3se000520 306
general geographic and stratigraphic distribution tab-
HAC = sc cmmoecocese oor sseugs ot ssecasecesecseScson 106
type specimen figured................ ---- Pl. LXV, fig. 3b
Taga, GEXCMS ECL - ...22coocasassscessceg sesesscoe- seb ye aeees 692
general geographic and stratigraphic distribution tab-
DWEHEG. ooo cos coses seenscysoscoc sscoosssosrcessseaos 106
type specimen figured. ....- Pl. LX VIII, figs. 3, 3a-b
marjumensis, described......----- 693
cardinal area discussed 305
general geographic and stratigraphic distribution tab-
(EOC, con ssensccostsesctoorecssecaseteossaceeseneS 106
type specimen figured. . - Pl. LXXVIII, fig. 2:
microscopica, described 693
compared with Acrotreta microscopica missouriensis... 694
Acrotreta microscopica tetonensis.....----------- 694
AGOGO QUIS coc nscccns ens 208s 2 cosssn0es=059 699
Acrotreta schmalenseéi...-.--------------------- 709
Acrotreta shantungensis......-.----------------- 711
Acrotreta signalis....--- 711
false area in, discussed. -- - - 674
general geographic and stratigraphic distribution tab-
(WENT. oso ongacscomconenednosostsancessosnasSseos0e 106

type specimen not figured.

816

Acrotreta microscopica missouriensis, deseribed......-..----------- 694
general geographic and stratigraphic distribution tab-
UAH Cs ee) wees noel Ma P Ea SRO Repco 106
type specimen figured ..--..-.---------.- Pl. LXVIL, fig. 4
microscopica tetonensis, described .........-.---------------- 694
compared with Acrotreta microscopica missouriensis... 694
general geographic and stratigraphic distribution
UD OVbIE TIS 8 od Space de socos concn ccoteccee sceosscus 106
type specimen figured
minima, described..-.-..----------------------------------- 695
general geographic and stratigraphic distribution
Tis ORHUEMICEl. =a --soscosessecece sco Kala)
type specimen figured... IBIE LXXV Il, fig. 7
mmiserd, GeSCriped.- = - ape eee eee eee ee 695
compared with Acrotreta curvata..-..-..-------------- 673
Acrotreta kutorgai_....---.--- 673
Acrotreta schmalenseei 673
general geographic and stratigraphic distribution
HIQWIENIEC = ocacaceoseneessonstsossacessosss0qcsse50 106
type specimen not figured.
meboensis, described. .......-----.--.----------------------- 695
compared with Acrotreta marjumensis 693
general geographic and stratigraphic distribution
HOWE. -soocéesacse oso scee soesea see saeetesessoSe 106
type specimen figured...........--.--.

nicholsoni, described......--------
cardinal area discussed
general geographic and stratigraphic distribution

INCE soe esaceccess cosets eoseoesscsescsoeseuss 106
type specimen figured........-...------ Pl. LX XIII, fig. 1
“ef. nicholsoni Matley,’’ discussed 703
Hie, CEXG MoO = ooo oc otis eso so sass seSasos sees ees sStS 696
general geographic and stratigraphic distribution
iff ONWNEHKOGL . - Sasso ssces2 coe searscosszessesesssoes 106
type specimen figured..........-.--.-- Pl. LXXVII, fig. 10
ailipildn, Glesouibyeel.— —— - <= == = 522 ence soz sss 392522 s32 697
general geographic and stratigraphic distribution
iiajoywlleyiel . ~ - 5-5 -oc2-sccicecanossorosseososseseds 106
type specimen not figured.
ophirensis, described.....-.--------------------------------- 697
cardinal area discussed 305
compared with Acrotreta microscopica missouriensis . 694
Acrotreta cf. ophirensis ........--.-------------- 698
Acrotreta ophirensis descendens.......---------- 698
Acrotreta ophirensis rugosad......-..--.--------- 699

general geographic and stratigraphic distribution tab-
(late dee eee

muscle scars discussed .

type specimen figured

I Fe PHONE TESS yh CSC TOE Clee eee
general geographic and stratigraphic distribution tab-

106

ophirensis descendens, described 698

cardinal area discussed 305
general geographic and stratigraphic distribution tab:

TUT) eG Cee 106

type specimen figured......-...---.--- Pl. LX XVIII, fig. 1

ophirensis rugosa, described... ...--.----------------------- 699
general geographic and stratigraphic distribution tab-

WOO oe ane ctiesasdceoteoseteosccse 106

type specimen figured . Pl. LXXIV, fig. 2a

OvGLS, GESCLIDEM. - ---—— = ee we me ee 699

GIS TISSE Cle ee ee 685
general geographic and stratigraphic distribution tab-

ulated 106

type specimen figured Pl. LXVI, figs. 2, 2a-b

pucifica, described.....---.-.------------------------------- 699
general geographic and stratigraphic distribution tab-

THING! 45.5 sececcceoedessesteob aces seercesssosss0=54 106

type specimen figured... -. Pl. LXIX, ies. 6 and 6a

“‘papillata,’’ compared with « Acrothyra Signata sera”’ __..-- 716

reference to Acrothyra sera discussed...-.-..-------- 716, 718

“papillata lata,” reference to Acrothyra sera discussed -...716,718
“papillata prima,” reference to Acrothyra sera discussed.. 716,718

parvula, described.....------------------------------+-+---- 699
general geographic and stratigraphic distribution tab-
(OU EYElE e Ao oonedSaeccbscnesousnoseasosoncnste 106

type specimen not figured.

CAMBRIAN BRACHIOPODA.

Acrotreta primzva, described ..........-..--.-------+------------- 700
compared with Acrotreta claytoni._.. - Jonoaebccodsndada 681
Obolus ( Westonia) ella........---..-..-.-.- -.- 672,674

general geographic and stratigraphic distribution tab-
lated ayes eee 2 106
one of largest species 674
stratigraphic position mentioned 318

type specimen figured...........-- Ln eaeasone
“nroavia,” type of Acrothyra. .
pyvidicula, described
general geographic and stratigraphic distribution tab-

(WIEN KG bee eee Semen Noman soo MeR eo 5 SoSaSeHose 106
stratigraphic distribution mentioned - 674
type specimen figured._............-- Pl. LXIX, fig. 2f

“recurva,”’ type species of. Volborthia....-.-.-.------------- 366
OAS, CMG MN. = ose be ocesesse=25ee so505500 ssooos Hosesess 702
general geographic and stratigraphic distribution tab-

HK Cl RE aoncoocaaesSeocuaesacceerecascorcecocanned 106
type specimen figured. - Pl. LXV, fig. 3f

Rul iiypea, Cleon Vl. 5 < ee cocascessseoesorecpasscas22easecesss 702
compared with Acrotreta bisecta.......-.....--------- 679
Obolus (Westonia) ella...........--.------------ 674

general geographic and stratigraphic distribution tabu- —

Label! 2/8728 ie Sa a AN oe ete ohtere teary Pee ee eee 106
type specimen figured -.- . . Pl. LX XIII, fig. 5b

“sabrine malvernensis,” discussed. - - 703
saggittalis, described - --.-...-.----- 704
compared with Acrotreta baileyi 677
VAlCTOUNaLONDELLO LL eee eee ee eee 678
Acrotreta belti...-.- 678
Acrotreta convera. -- 682
Acrotreta curvata - 673
VAICTOUNCLONUTU LALO eee ae ee eee eee es 691
VAICTOUTELMULOT GO Leese eee eee ea eee Ere 673
Acrotreta pacifica.. - 700
VA\CTOUTELA Chay SUGULMUI Sine eae eee een 706
Acrotreta sagittalis magna..........----.-------- 706
Acrotreta sagittalis taconica.....-.......---.---- 707
Acrotreta sagittalis transversa....-....---------- 708
Acrotreta schmalenseet 673
Schizopholis 609

general geographic and stratigraphic distribution tabu-

TENG. sasotaccwsedooscséowoosecoseoSapauoosasopso0e 106
type specimen not figured.

CL Sagiital1s, CESCLIDe ere = ele eee =e eee eee eee ae 706
general geographic and stratigraphic distribution tabu-

TCM eine a SMosisB access seaEErecoUOepecscossac 106

sagittalis magna, described. ..--....------- 706
compared with Acrotreta baileyi. --.--.--------------- 677
Acrotreta cf. socialis......-.- Sees (Ales (ils)
BACT OMTCLONS O aiUL0 Ol Use ese ee ee eee 715
(ObGERROC - - coctascaessebscscsctessetaseesoesasces sau Yl
general geographic and stratigraphic distribution tabu-
106
type specimen figured. ..-.--.--...------ Pl. LXVI, fig. 4b
Sagittalis taconica, described = 2- = eee ee 707
compared with Acrothele subsidua.......--...-------- 633
VAlCROFTICEOAD OC Dea ee tee eee 677
general geographic and stratigraphic distribution tabu-

IBYe ae coed oecsecdaun dcbecuddeasobacmocouncucedseous 106

type specimen figured...........-.....-- Pl. LXXI, fig. 1e
sagittalis tramsversa, described. -.--.-...-------.------------ 708
compared with Acrotreta baileyi. ......---.----------- 677
PACT OUNELONC UMUC Cate eee eee ee 673
VAC OLTELCNCLLLON GO Lea as eee 673
Acrotreta sagittalis magna.....--.-.------------- 706
Acrotreta schmalenseéi......-.--.--------------- 673
general geographic and stratigraphic distribution tabu-

I Kia EN eee so Sones se se se asosaccesadedoosts 106
type specimen not figured.

schmalensee, described): +. 2f2- 2-2-2. ee = 709
compared with Acrotreta ovalis.-...--.--------------- 699
Acrotreta sagittalis transversa 673
Acrotreta seebachi. - 710
Acrotreta socialis 712

general geographic and stratigraphic distribution tabu-

IEWKaG Weegee epsceoubodsacesacadeasoesqocaeqessesesogs 106
type specimen figured......--....----..-. Pl. LXX, fig. la

: INDEX.

Aicnotreta seebach?, described. ----.-s2---+ssceecea-cecccen sce aces 710
compared with Acrotreta carinata..........--.-.----- 680
PAICTOLTELONCINE2LLOT.S ta eee eee eee eee 680
general geographic and stratigraphic distribution tabu-
ated ties soe ebocee a see eeaee aan aoe Seals 106
type specimen figured.........-....... Pl. LXXVIL, fig. 3
Shomtungensis, described = «22 ---ses--esseceseneenceeseeee se 710
general geographic and stratigraphic distribution tabu-
EG a SaaS oe SR OR Cee SR Emenee Bors Ce Sec acereictec 106
type specimen figured............. Pl. LXIX, figs. 5, 5a—b
SIGTLELIS | GESCEIDG Cathe 12 25 of efe Sotae wale avons Baa eee eee 711
general geographic and stratigraphic distribution tabu-
LEGS er Rar RASA He Se ee see ANE eae Ene eter 106
type specimen figured
*‘sipo,’’ discussed......----

Socialis, described... .
association mentioned..................--.--
compared with A crotreta carinata

PAICTIOUNELO) SCRTUGLENS CCbe nee a =e eee ee eee eae 709

Acrotreta seebachi.... 710

ACRE BOs WiChis co sosaobassosscossceenasacsa6 715

GISCLISSE Sea ease ae, Sait aS Sel ae eee 703

false area in, discussed... -/...-...--..--.------------- 674
general geographic and stratigraphic distribution tabu-

latede.toncoe cbs eae a eee eaace eae ce 106

type specimen figured.......... Pl. LX XIII, figs. 3 and 3a

socialis Gronwall, discussed.........-....-..--------------- 712
socialis Linnarsson, compared with Acrotreta socialis von

SEE, a Aesnasseoseuaassabasnooueason ‘ cos YOY)

712

709

703

cf. socialis Matthew, discussed 712

spinosa, described-....--.-- SESS REESE SaCRcee Meee pie eRe Se 713
general geographic and stratigraphic distribution tabu-

2 106

surface ornamentation discussed . . 302, 672

type specimen figured............-...- Pl. LXXIX, fig. 4b

Guinan das CCRC al Xe ee onedanaetonseseans abcnacseceacconoen 713

compared with Acrothele coriacea is 642

Acrotreta gemma-...- =. 685

Acrotreta schmalenseei - . oo AO)

PACH OUNELOISOCTLUIS meres eee ee ere eee eet 712

false\arealin discussed. -scess- 2 = ee eeee ease eee 674
general geographic and stratigraphic distribution tabu-

106

673

Sao, «C8

type specimen figured... - Pl. LXXIII, figs. 2f and 2g

airicht described ars scten st eee ees sees ese eee eae 714
general geographic and stratigraphic distribution tabu-

labed eps eeepc teens semen secs se anne aeiee seek ae 106

type specimen figured... = Pl. LXXVIIT, fig. 3

yaar, CES ON NS oo Seon S pt bonecnen sass seessneesbenass 714
general geographic and stratigraphic distribution tabu-

Nabe dete oe nase mine nas nee nee eeeietiseiae ee eee 106

type specimen figured..............- Pl. UXX, figs. 3, 3a-b

uwplandica limoensis, described...........-...-.-.-------.--- 714

compared with Acrotreta wplandica................... 715
general geographic and stratigraphic distribution tabu-

latediiis Ae ekeseceiasaeemas Biseeiach (sees pee ee ee OG

type specimen figured............... Pl. LXX, figs. 4, 4a-b

sp. undt., described ...-.- =o es 715

discussed emer eeseeraeee eee eee Se tapers ore aS 712-713
general geographic and stratigraphic distribution tabu-

IEVIGGl ~ snboconabocooossnodcsosbosotoces sosesceonace 106

type specimen not figured.

spaundt.wrestergands described s-2. eee se= a2 ease see ase 715
general geographic and stratigraphic distribution tabu-

IPR Soccecisrececasousotsnodocorassosesarscescen 106

type specimen not figured.

Acrotretacea, classification of.........-..-.-.--.---------------- 321,324
distribution in Cambrian strata.............-.------------- 316
genera and species referred to, described - 630-721

Acrotretide, classification of........----.----------- -- 321,324
distribution in Cambrian strata-.-.-...-.--.---- -. 315,316
genera and species referred to, described.......-.--.---.. 630-721

62667°—vo1 51, pr J—12——52

817

Acrotretidze—Continued.
general stratigraphic distribution and number of Cambrian

PENETALAN SPECIES Olja saeco ee eee Rese ee eae 112
number of Cambrian genera and species of- 112
number of genera and species in monograph..-...--..-----. 113

number of Ordovician genera and speciesin monograph.... 113
Alcrotretinee, Classification Of. ees-e4-seeees eee eee ese
genera and species referred to described
acuminata, see Lingulella (Lingulepis).
acuminata mecki, see Lingulella (Lingulepis).
acuminata sequens, see Lingulella (Lingulepis).
acuminatus, see Obolus (Schmidtia).
acutangula, see Lingulella.
Adairsville; Georgia; locality, at..-----2---+ se-- esse seee eee
Adams, Frank D., acknowledgments............-...-..---------
Adams County, Wisconsin, localities in.......-....--..------
Adams Hill, Eureka district, Nevada, localities at
Addison County, Vermont, locality in..........-...<-----------ss
Adductonmusclessdetinedeeseeeeeeeeee eee eee eee eee ree eee eee
Adrados, Spain, locality near
advenus, see Obolus.
affinis, see Obolus (Lingulobolus).
Agassiz, Alexander, acknowledgments.............--..---.------ 12
Age, characters of old age discussed..............----------------
agnostorum, see Lingulella.
Agnostus, association mentioned...
mentioned sass ss s5
fallaz, association mentioned.........-.....-....-.---.-----
gibbus, association mentioned
interstrictus, association mentioned . 2
truyensis, association mentioned...........-..-.-.---------- 499
levigatus, association mentioned ..............----------- 476,700
levigatus zone (Middle Cambrian), in generalized section for
Sweden, Denmark, Finland, and Norway, listing
Species; anGilocalitiesse = seeeer eee neces eee eee eeeeee 145
Jocalitiesinea=-eee-eneee sees 310q, 320b, 320r, 320u, 321p
parvifrons zone (Middle Cambrian), in generalized section for
Sweden, Denmark, Finland, and Norway, listing
Species and localities.
localitygin’s=eeee ee saeeees
punctuosus, association mentioned

Agraulos socialis, association mentioned 498
agreste, see Hoorthis.

Akarpsmilla, Sweden, locality at --- 309e
Alabama, Cambrian species of, listed..-......------ pee meron 114-119
generalized section of Cambrian in, listing included and cor-

relatedispecies and localitiesss-os-cee-e- ese see ea ee eee 147

localities in-....... 16, 17b, 56c, 560, 56q, 56u, 89, 90, 90a, 90b, 90c,
90x, 91, 92x, 93, 93a, 93n, 930, 93x, 94, 94a, 940, 94x, 94xx,
95a, 137, 138, 139, 139a, 140, 141, 142, 144c, 145, 146, 146f, 361
alabamaensis, see Micromitra.
dlandensis, see Obolus (W estonia).

Aland Island, Finland, localities‘on ..-....-..-. 311d-f, 311q-t, 31lw-y

alata, see Syntrophia.

Albany, New York, locality mear.----.-.:..-.2-.-.-+----s2---2:-- 72

Alberta, Cambrian species of, listed...........-....------------- 114-119
localitiesyin 224: = ale ele ne Oe ees haere eye crere 35d, 35e, 35g, 35h,

57e, 57d, 57g, 57k, 57s, 57y, 58f, 58i, 58t, 58w, 58z, 60b

species and localities in, correlated with those of British
Columbia oS aes seet cere ce see sane: eee nace orem. 125-131

alberta, see Nisusia.

PAN Dentel Melero mentioned eee see eeetree eee eeeer eee eects

A lbertella helena fauna, mentioned............-...----.--.--------
Alemtejo, Portugal, locality in-.......-
Alexandria Bay, New York, locality near.................
Allamakee County, Iowa, locality in-...........-.-...--.-
Allan, J. A., Upper Cambrian formations named by

work on Cambro-Ordovician boundary in British Columbia. 125
Allumette Island, St. Lawrence River, Canada, locality on. -....- 319p
Aman Wisconsin localiivaltee=seeeererensseEeenecereeareeeee cee 328¢
Alpha Station, Nevada, locality near..............---.--.-------- 313¢

alta, see Acrotreta idahoensis.

Altenhof, Esthonia, Russia, locality at...
Alum slate (Upper Cambrian), locality in z
Alunbruk (alum works), Oeland Island, Sweden, localities at...

309j,
309m, 320q, 321x, 390
Amargosa River, California, localities east f......... 141, 14n, 140, 14p

Amberson, Alabama, locality near. - 8a

818 CAMBRIAN BRACHIOPODA.

ambigua, see Elkania.

Ami, Henry M., acknowledgments 12
bibliographic reference. --..-------.-- 13
species named for.......---......-.----.----.--. atte eet 731

amii, see Nisusia (Jamesella).

Amis post office, Tennessee, locality near..................-.--..- 12la

Amour, see Point Amour.

ampla, see Lingulella.

anceps, see Obolus.

ancillus, see Obolus.

Anderson County, Tennessee, localities in............--..--.-- 7d, 374a

Atndnanuims Swed Cn) OCH estat release = ease eee re 8w,

3101, 320c, 320f, 320i, 3200, 320x, 321ly, 3900
Andrarum limestone (Middle Cambrian), in generalized section for
Sweden, Denmark, Finland, and Norway, listing species

andilocallitieS eam eee se see eae ae eee ee eee 145
localitiesiin 3 ss2tge asics «hee sees see seesee eee 320¢,334b, 334e
«« Annelid sandstone,”’ mentioned .........-.-.-.-.--------------- 539
anomala, see Wimanella.

““Anomites lenticularis,” type of Orusia........------.------------ 765
Anopolenus, association mentioned......-..-.-..----------------- 498
venustus, association mentioned.......-...--..-.----------- 498

Anse au Loup, see L’ Anse au Loup.
Antelope Spring, House Range, Utah, localities near__........... 3s,
: 3t, 3x, 3y, 4, 8g, 8i, 8k, 1lo, 11x, 30d, 31s, 31v
Antelope Valley, Eureka District, Nevada, locality in. 59

Anterior lateral (retractor) muscles, defined......-.-..-.--- - 292
shown in figure_........-.-------- - 374

Anterior region, defined 292
antiquata, see Swantonia.
antiquissimus, see Obolus (Acritis).
A parchites? anderssoni, stratigraphic position of bowlder contain-

ings GISCUSSEOs a-ak es eee eee econ caesar ea 454, 684
A patocephalus zone (passage beds), in generalized section for Swe-

den, Denmark, Finland, and Norway, listing species and

localities - . 144
locality in. -. 390e
Apex denned sepa eae incor ere Rete seeeaan eee seer ee tee ease 292,
Apicalicallosity defined sapere ete tee eee ete ae eee eee eae 292
apollinis, see Obolus.
apollinis ingricus, see Obolus.
apollinis maximus, see Obolus.
apollinis quenstedti, see Obolus.
appalachia, see Billingsella and Dicellomus.
Appalachian province, Cambrian species in, listed.........-..-- 114-119
Arbuckle limestone (Upper Cambrian), detailed section, listing
included and correlated species and Jocalities........... 141-142
LOcaLIbies\ilse ste ae cae = Soeee Romo melee eee eS 9z, 12j, 12m
Arbuckle Mountains, Oklahoma, detailed section of Cambrian and
Ordovician in, listing species and localities. ............- 141-142
LOCAL yin ey ee pects ea tee cetera a ater acre eee oe =e ie 12p
Archeocyathinze white limestone (Middle? Cambrian), locality
I pechotene Snbs SS ASS SIRO be clo sscpe dog acaseise SES aHOISOSR 315¢
Archzxocyathus, association mentioned..........-..---.----------- 584

Archangel Quarry, near St. Petersburg, Russia, locality at.......
Arcola, Minnesota, locality at------- 022-222. 2-2 eee eee eee
Ardmillan Brae, Scotland, locality at....-..........-.-.----.----
Ardmore quadrangle, Oklahoma, localities in....-.....-. 12h, 12m, 12n

Ardrossan, Yorke Peninsula, South Australia, locality near 315a
Aneesh ets bed Seele GrsamsasccasbocandsskedecseacrisoneS == 1292,
Showmlinsh pune spss seine Se tcssiieiseres ohele ame Ree eee 374
Arenig, in generalized section for England, Scotland, and Wales... 1385
Avenig, North Wales, locality in_-----....--.------ 4. 305e
Argenta, Big Cottonwood Canyon, Utah, locality near............ 30a
argenta, see Acrotreta and Nisusia (Jamesella).
Argentina, Cambrian species of, listed..........-.....------------ 122

localities in

argia, see Syntrophia primordialis.

arguta, see Lingulella.

Argyle, see South Argyle.

Arionellus, association mentioned............--.----------- 598, 600, 767

Arizona, Cambrian species of, listed...-.........-- -- 114-119
Dicellomus politus from, discussed 577
localities in-. 90, 14x, 17c, 73, 73a, 73b, 74, 74b-d, 75, 358, 358a—b
stratigraphic position of brachiopod localities in, discussed... 124

Armstrong Creek, Tennessee, locality near.............-.....-- mo bby

artemis, see Acrothele.

Articulata, distribution in Cambrian strata............--...--. 316
SHEN SCC CHINE Ol pense tee eee eer eer Eee eee eee 296

|) Atticulateibrachiopods defined =e ss= sarees sess == seein 292
Articulating processes, discussed..-.....-....-------------------- 307
““Asaphelins fauna,’ mentionedes = 45222 e-e ose eee seeee ne 679
Asaphellus zone, in generalized section for Cape Breton, listing in-

cluded species and localities.........- 131
Asaphiscus wheeleri, association mentioned 658
Asaphus bréggeri zone, in generalized section for Russia.........-. 143
Asaphus eichwaldi zone, in generalized section for Russia........- 143
Asaphus expansus zone, in generalized section for Russia. .......- 143
Asaphus lepidurus zone, in generalized section for Russia......... 143
Asaphus raniceps zone (Ordovician), in generalized section for

Russia 3.524 ia ks sg eee ees ae tee ee eee eee eee

locality: an! oa2 oe aS ak os potatoe toto os ein ee
Ash Creek, Arizona, locality on
Asia, zoologie list of Cambrian species of, giving distribution by

coumtries: oo. ne toscn aise pon seins see see ee eee 121-122
asiatica, see Obolella.
Asserien, Esthonia, Russia, localities at........... 395c, 395), 395p, 395s.
Asterisks in localities, explanation of-.........---..-------+----.- 160

atava, see Hoorthis and Lingulella.
atava insule, see Lingulella.

Atherstone; Eneland> locality ine= «--seesee- eee eeee eens ease eeee 304j
atlantica, see Obolella.
Atlantic coast province, Cambrian species in, listed.......-...- 114-119
Atremata, cardinal area discussed ........-...-....-- Sotnsaser s 303-304
Classification: ofc: << sess. a2- ae sae ese eccia ee see ene ene 322
292
SOSHORS - 327
distribution in Cambrian strata. - - 316
evolution of genera of, discussed.............-.----.---.-- 318-319
genera and species referred to, described ....-...........- 327-585
holoperipheral growth of pseudodeltidia in - 306
musele/scarsidisctissed= === eee sane eee eee 5 312
pedicle furrow discussed :------ 2222 2---2--- 2s - 814
surface ornamentation discussed 301
vascular markings discussed 311

atrypoides, see Orusia lenticularis.

Attala; Alabama, \localityiatese-sseece eo ee ee ee eee eee eee eae 361
attenuata, see A crotreta.

attenuata var. ?, see Acrotreta.

Attleboro, see North Attleboro.

auga, see Lingulella.

KCARMONOt eta Pola, MenOUed a - eee ae ee een ee eee ee eet eee eee 383
aurora, see Obolus (W estonia).

Aurum, Schell Creek Range, Nevada, locality near__............ 80
Ausable Chasm, New York, localities in.....-...-....-.-...-.. 77, 338t
Ausable River, New York, locality on............-.....-...:---- 338s

Australia, see South Australia.
Austria-Hungary, see Bohemia.
avia, see Acrothele.
avia puteis, see Acrothele.
“ Avicula desquamata,”’ discussed......-.-----.-.----------+------ 594
Avyzshire; Scotland locality intes--e5---e-neehe see eeeeeeneeeseeee 316a
A, treated as A in this index.
babel, see Acrotreta.
baileyi, see Acrotreta.
Bala, North Wales, localities near..................--....-- 366m, 3660
Bala (Coniston) limestone (Upper Cambrian), in generalized sec-
tion for England, Scotland, and Wales, listing species and

localities.:. 352 ac'b2¢ 3Bas a! Sas hota eee ee ce ee eee eee 135
locality in
Bala Road, North Wales, localities on ................-.....- 305f, 366)
Bala schists (Upper Cambrian), locality in 3660
Balbriggan, Ireland, locality at......-.....---.-.---.-+----------- 317a
Balcletchie, Scotland, locality at..--..-..-...--.2--2222-2.22--2- 316a
Bald Mountain, Bighorn Mountains, Wyoming, locality near.... 170
Bald Mountain, Washington County, New York, localities near.. 35,
35a, 338h, 338z
Baldwin’s ranch, Texas, locality at............-.----------------- 14c
Baltic region) localities im. -----s--2--eere- eee = 395f, 396e, 396f, 3960
See also Esthonia, Finland, Sweden, etc.
balticus, see Obolus ( Westonia). ,
Baltischport, Esthonia, Russia, localities at...............-..---- 336h,
336m, 336r, 337i, 3371, 395x, 396, 396x
Baltischport Peninsula, Esthonia, Russia, localities on...... 396a, 396n
“Bande de Jinec”? (Middle Cambrian), locality in... 345b
Bangor, North Wales, locality in.......... Rate eee ee 366d
Baraboo, Wisconsin, localities near.............---.------.---- 10v, 116
Baraboo quadrangle, Wisconsin, localities in................-- 10v, 116

ee

INDEX.

barabuensis, see Syntrophia.

Barachois, Nova Scotia, localities at...-.......2..2-2-ee0- 30, 100, 372c

Barachois Glen, Nova Scotia, localities in 3q, 10n

Barachois River (=McLeod Brook), Nova Scotia, localities on ...10c-i,
10k-m, 13h, 307, 307a, 307h, 372e

Bar Creek, Montana, localities near...........-....-..----------- 3j, 53
Barn Bluff, Minnesota, locality at...............-.-.---.--------- 113
Barnet quadrangle, Texas, localities in...............-..------ l4e, 14q
Barrande, J., bibliographic references. 13
species named for............--.---- 603
Barrande, J., [de Verneuil, E. P., and] bibliographic reference... - 24
barrandei, see Botsfordia.
Barrel Spring, Nevada, localities near.................--.- 1, 1m, 1p, lv
Barrel Spring section, in detail, listing included and correlated
species and localities.........-.. 137-138
Barrois, Charles, acknowledgments............-.-..--.----------- 12
bibliographic reference. ---.--.---2..--.- 2-00 een ewe e enone 13
Bartlett Hollow, Texas, localities in...................-------- l4e, 14q
Bartow County, Georgia, localities in.................--- 59m, 96x, 362
“Basal series” of Matthew (Lower Cambrian), locality in........ 301v
Bass Canyon, Arizona, locality in-...................-....------- 74d.
Bassler, R. S., acknowledgments. --. 13
bibliographic reference. .......-..-.--.--------- = 13
work on microscopic structure of Brachiopoda...:..-.-.--.- 297
Bastard township, Ontario, localities in...............-.---- 392b, 392e
Bathyurus, association mentioned ..........-..---.--------------- 493
Bavaria, Cambrian species of, listed - ---- 120-121
Nocalibiestineeresees ashe eere esac aaa 5 -. 308c, 303f

bavaricz, see Eoorthis.
bavaricus, see Obolus.
Bays Mountains, Tennessee, localities in............ 10a, 10b, 106, 106a

Bear Creek, Montana, localities on...--...-.-.-- 160a, 340f
Bear Gulch Valley, South Dakota, locality in.................--- 253a
Bear Lake County, Idaho, localities in...........-......---.----- 55e,

56f, 56g, 59f, 59¢, 163, 322, 322a
Bear River Canyon, Wyoming, locality in.......................- 340d.

Beauharnois, Quebec, locality near.

Beauharnois Canal, Quebec, locality on.................-...----- 319t
Beaver County, Utah, localities in.................-..-...-...- 34r, 34t
Beaver Creek, Montana, locality on..........-....-..--.--------- 9h
Beaver Creek, Wisconsin, locality on.................-..--------- 79x
Beaver limestone, in generalized section for Tennessee, Georgia,

PhiGl Nb opin oo esscooducsuccuouedcocooascocerTasoscasasS 147

Beaver Mountains, see Cricket Range.
Beaver River Range, see Cricket Range.

Beecher, C. E., bibliographic reference..............-...--------- 13
Rustella compared with “ Paterina”’ of. . 328

Beekmantown limestone, Division A (Ordovician), locality in.... 367c
AAA NOTH 0 sos sossce sosceeeecesetoacetcossessacsessssoccos 551

Bell, A., species named for 386

bella, see Lingulella and Micromitra (Paterina).

bellapunctata, see A crothele.

bellatula, see A crotreta.

Belleisle, see Straits of Belleisle.

Bellewstown, Ireland, locality at...--....-..---- 2-2-2. - eee ee eens 317a

velli, see Obolus.

bellula, see Acrothele and Lingulella.

bellulus, see Obolus (Fordinia).

Belschwitz, East Prussia, locality near..............-...s.--.---- 386

belti, see Acrotreta.

Belt Mountains, see Big and Little Belt Mountains.

Belt) Park, Montana, locality im-- =. - 22.22.52 2 ecece eee e ce eece sn 4x
Beman Park, Troy, New York, locality at
Bennett’s Spring, Nevada, locality near.....
Beraun, Bohemia, locality near
Bergen Park, Colorado, locality near...............-2.2-0--200---
Bergeron, J., species mamed) for. 2s eees enim ceie sens ee ceeee =
bergeroni, see Acrothele.

Berlin, Wisconsin, locality at.......-. 328d
Bessemer, Alabama, locality at. 56u
See also South Bessemer. j
Bethany Chapel, Tennessee, locality near....-.-............:-..- 2z
Beyerly, Ontario, Lingulella (Lingulepis) acuminata at, dis-
CUSSE Games e trae seeee soca eeee rin seceste cee ecce 547-548,
localitygatech pees ease --. 392b
Bibb County, Alabama, localities in..................--..----- 90b, 90c
IBiblioprap hiya saree. acs a ccc = Sees co cncle ce eos Seca cela woes 13
Bicn@uebecocalitiesiateerceeesssencceseecseceeceeteeneeee 20, 2p, ar

IddaTi CEI OMEC |S poco nom pene naoobe men aeacoobaggNobocoSseeCBeon 568
articulating processes discussed......----------------- 307

Cardinal area discussedice.pe-eeeeeeeeeeeee == <= -- === 304
classification of..............---- . 321,323

compared with Linnarssonella........---------------- 665
Trematobolus kempanum......----------------- 620

evolution discussedseesee pee eee eee eeeeeeeeseee= sss 318
evolution(on she tteen serie eee ee ee ser cee 317

general geographic and stratigraphic distribution of
the species referred to.....-......-.---------------- 103
general stratigraphic distribution and number of Cam-

brian species and varieties of......-.-.------------- 110
muscle scars discussed 312
number of species of, in different types ofsediment... 160
stratigraphic position mentioned........-.-------.--- 318
type species “‘ Obolella gemma”’.........--.----------- 569
vascular markings discussed.............-.----------- 311

gemma describe deesesee meee 1 eee neiteecneeetecticae eee 569
compared with Bicia whiteavesi.........-------- 568, 569, 571
(QUAM. = secosseanesenbo> 588

Obolella? lindstromi...... 596

Obolella mobergi......-.--- 597

Obolella (Glyptias) favosa 600
Brematovoluss <= -25 5 sete ahs eps oe Ee ee eee 615

lated heey OM tetem sere ote aee ocean cine heen eaetae 103
surface ornamentation discussed ...........---------- 302
type specimen not figured.

awhiteqvest | GeSChiDed a. mene eaeese cee access 570
compared with Bicia gemma......-...-------------- 568, 569
LEO S CHM aergasaccsestso2esoecsoeenes 568
discussed 568, 569

general geographic and stratigraphic distribution tab-
HUET Cane eocased socnoacaneacecnempecoanooDlasns 103
type specimen figured........-..-!..-...-.-- Pl. L, fig. 2¢
Biclines;classificaviontOl-eeereReeeEeee Eee e eer eee rete ater eee 321, 323
genera and species referred to, described .............----- 568-578
Big Belt Mountains, Montana, locality in..................------ 9h
Big Cottonwood Canyon, Utah, localitiesin............... 30a, 33i, 55u
Big Creek, Tennessee, localities on 123, 124, 124a
Big Goose Creek Canyon, Wyoming, localities in............- 171, 17la
Bighorn Mountains, Wyoming, localities in................-.---- 14k,

168, 170, 171, 171a, 302m, 302u, 302x, 302y

Big Ridge, Cape Breton, locality on................---.-...------ 1lz

Big River, Missouri, locality on..................-.-------------- 369e

Bigsby, J. J., bibliographic reference. -..-.-.--------------------- 14

Billingen, Sweden, localities at and near............--.-.--.- 309c, 390k
See also Mount Billingen.

Billings® b-, bibliographiemeferences=2--22 4-24-22 e see eee 14
genera named for 562, 750
species named for 483, 740, 806

LRQA Mt, COCHIN) = 2c 5c nos ac ogec Se SecasGoenssoCoSSodseseee 749

articulating processes discussed . 307

Gaifelivaval | Aniee), GUSOUSSE!. -~ co eeoscHondbcacscossesmees 304, 305

cardinal process discussed..............--.----.------ 306,
Classificationioleperesere coe secie ae ee ee ee ee eeeee 321, 325
compared with Hoorthis..........-...-.--.-.--- 755, 772, 773
Hankel nbn ged) OSCeold eee |e eeeeee 795
SN suistalays Sick a clause) ae meme Ns eae 306, 725, 726
OMNIS crceeat Saas iam cmenetecees see sos 772, 773
Plectorthis whitfieldi by Ulrich 308
Wimanellans ok 2atdsae cet see cece eee sain ss 745
VAY TUNG aor eens Naaeeclenye See ee see e 771
cruralium discussed ..... 309
deltidium discussed... - 2 306
evolution discussed... -- 319, 320
evolution of 317
general geographic and stratigraphic distribution of
juheispeciesirelerneds tose teen eee eee eer ee eee 107-108
general stratigraphic distribution and number of
Cambrian species and varieties of......-.-.-....-.. 111
TMOMMOMe deen ss eee tae ee ete 492
MUSCleSCALSIGISCUSSeC seen eee eae epee eer eneee == 313
number of Ordovician species and varieties of ..-...-- 113
number of species of, in different types of sediment. 160
pedicle tube discussed... ... 315
pseudodeltidium discussed - . 313
pseudospondylium discussed 307

820 CAMBRIAN BRACHIOPODA.

>
Billingsella—Continued.
reference to, of Otusia sandbergi discussed........-..-- 770

reference to, of Syntrophia unzia discussed - - -- = 805
reference to, of Wimanella anomala discussed - - 746
stratigraphic position mentioned --..-.-...-.-..-....- 318
type species “ Orthis coloradoensis”........----------- 749
Ulrich on spondylium. .------.--.---.-- . 308
vascular markings discussed. .---.-..---- 311
? appatachia, described.---..----------------- Z 750
compared with Wimanella shelbyensis.. - - 747, 748

general geographic and stratigraphic distribution
tabulatedsehen sete saee eee eee ee eee eeeC eens 107
type specimen figured.

(ity GSO INL. ae s25s5scseseseosssselonesoosesesosssse25 750

general geographic and eee distribution tab-
Wlatedisscest ooo eee nee ce eee ae eae ee eee 107
type specimen figured Be . text fig. 65A, 750
coloradoensis, described). = 22-22 =.= 222. =e =e eee een 7a
compared with Billingsella highlandensis.. - 756, 757
Billingsella lindstrémi-.....--.-- 5 aye
Billingsella major....------- - 758
Billingsella obscura. ...----- - 758
Billingsella orientalis. -..-....-----------.------ 709
Billingsella plicatella......-- .-- 745, 760
Billingsella pumpellyi......-------------------- 761

Billingsella retroflexa..-.-.-..-..----------+-----

Eoorthis johannensis --.-
4 Wimanella harlanensis......--.---------------

Wamanella sumplenan= see ee aan ee
deltidium discussed
general geographic and stratigraphic distribution tab-

i saibe eee a rae ees eae eso ae aeree eee eee a 107
pedicle opening in..
shell section figured. .
type specimen not figured.

Mile, CESCHIRGC seen eee eee see eer aan eee 754
GISCUSSE Eee eee eee See ee ee ee ee 750
general geographic and stratigraphic distribution tab-

(hyn en ee eee eS Ce Ste seecmctaene-eneccouse 107
type specimen figured .................-.----- Pl. CI, fig. 8

Gaplainaite, CUS SEG le = ot coeees Joon oe sergaceccs 754

compared with Billingsella exporrecta rugosicostata.... 705
EB THLTG SCLC OS tee ea eee eer 756
Eoorthis linnarssoni... 783
Wimanella harlanensis 746

discusseG*essGeepees ae eerie aoe 750

general geographic and stratigraphic distribution tab-
WENO oo 2202 send eseue asso Jasons seussseascceaceces 107

intermediate between Billingsella and Hoorthis....--.. 735

type specimen not figured. :

vascular markings discussed.........-.-.---.--------- 311

exporrecta rugosicostata, described..........----------------- 755
general geographic and stratigraphic distribution tab-

QUE a6 ee ete ee a SE EEE sam amen Soa S nas 107

type specimen figured Pl. LXXXVIII, fig. 2

G5), COSOMI GL A =) beesoessosscass cone tous ceasszassee0= 756
compared with Hoorthis linnarssoni.......------------ 783
general geographic and stratigraphic distribution tab-

UAE Ye Se eR ee er IRON GREE EASES RaOS SS SESSS 107
type specimen figured .........- Pl. XCVOH, figs. 7 and 7a

highlandensis, described. ---.--.--.--- 756
compared with Billingsella bivia 750

Billingsella plicatelia-... 745

Wimanella simplex 748

general geographic and stratigraphic distribution tab-
MUlated tess oo stees e e celeeee eee eenee eee ere 108
pseudospondylium discussed........-..-------------- 307
type specimen figured -.......-...- Pl. LXXXVII, fig. 4b
lindstromi, described 797

general geographic and stratigraphic distribution tab-
WR os ss ouaamede sda anosanoaceeeodsceseeors Spenee 108

type specimen not figured.

MLR; GELOM OY As -- -clrosee= so set oaraose= sesesosaasess - 758
compared with Billingsella coloradoensis 752

general geographic and stratigraphic distribution tab-

ERE <5 adage co soos u ess eoseesencae. seasecce O55 108 |

type specimen figured. - 5
Marion, \eSCLIPCGs == oa eee n= = an = alee a 758
general geographic and stratigraphic distribution

TEP NICG ls a2 Sess eseoececocoer ot ecseasoSsososseH35 108
type specimen figured

Billingsella obscura, described =22s--s2-2 222-2 ese ee seen 758
general geographic and stratigraphic distribution
tabulated S825 scan. sce ae o enl- Nefie eeeneeeeeee 108
type specimen figured................. Pl. LXXXVI, fig. 6
orientalis, described......---- 759
compared with Hoorthis johannensis.......-..-------- 781
general geographic and stratigraphic distribution
tabulated setae as acetate en ner e se eer 108
pseudospondylium discussed...............-.-------- 307

type specimen figured......-

plicntella CeSerbe dene ere reee eee eee eee 759
compared with Billingsella coloradoensis.. - 745,752
Billingsella highlandensis.......-..--.-.-.------- 745
Billing scllastrite eee eee eee eee 764
Huenella abnormis..-.------ 806
Wimanella harlanensis...-.----- ---- 745,746
general geographic and stratigraphic distribution
tabulatedeesseeess- neers eee eee aaa eee 108
intermediate between Billingsella coloradoensis and
Wimanella harlanensis.......-..--.----------------- 745

shell section figured ......

type specimen figured......

vascular markings discussed.........-.--------------- 311

(DIT PELYyU ACS ChIP CO em eee en ee eae ae eee ese 760

compared with Billingsella retroflexa...
general geographic and stratigraphic distribution

tabulated...) sean eee nce ee ee eee eee eee 108

type specimen figured. . Pl. XCVII, fig. 8

_. text fig. 1, 299

ane p lsu, Gleason so ssseos=d2s2ssesee202585555 761
general geographic and stratigraphic distribution
OWI CC Le pe sendo5 sags ose sces cose sossSsens 108
type specimen figured..........-.....--.-.-- Pl. XC, fig. Ih
PANO 0d, GESEMOCCL os sec sso sossosocsaccanAsoocoesorss 761
general geographic and stratigraphic distribution
tabulated sa. Be saeee to cch = onsen eae eee eee 108
type specimen figured..........-...-- Pl. LX XXIX, fig. 1
TOMMUNGET ty CESCLID eC Cee eae eee eee ere 762
compared with Billingsella dice......-...-------------- 754
Billingselia pumpellyte- ae ~ sor to eee 761
EBilling SELL EET Of 62: ewee ee eee eee 761
INGSUSTONP VOICI Sec es ee =e ean ae eee ee 730
Nisusia (Jamesella) Kuthani 733
Orthis tricenaria by Ulrich... 308
“Orthis sp. Pompeckj’’.-- “ 793
Wy iOvuarilteese nese ee ee eee 771
general geographic and stratigraphic distribution
AIDE. 68 ohs aces scccosccos =p saSnbecssaeseossc 108

type specimen figured.

sera qpeaeeseoas aces 763

salemensis, described -.....--

compared with Billingsella coloradoensis 752
(Billing SELLA TUT LOT eae ee ee te et 758
Billingsella whitfieldi........--.-.---.----------- 764

general geographic and stratigraphic distribution
(EV WIRMEC Soo 4etio srmacnsesecobesseseontcoseecceses 108
type specimen figured. -

Cindi, Co) GGl boa soshonejsoe sooeasmdsosescooreoeesose zs
compared with Billingsella plicatella.......--..---.--- 760
general geographic and stratigraphic distribution tab-

WIAD 2s sos~ Sood oo Jasessotsasceszezo2acssserse7e9 108

type specimen figured.......----.-----
WDNibfieldt.| CESCItD Bae ee =e ee ee
compared with Billingsella salemensis é
general geographic and stratigraphic distribution tab-

(HEWECL, Soc sdocnosccosese ss csome Uesosasseaceersccses 108
type specimen figured....--.--------- Pl. LXXXVI, fig. 5a
Billingsellide, classification of 321,325
compared with Ordovician Orthide--.-.-.----- =: , 320
Orthidz, by Ulrich. .------..------------- -- 308
distribution in Cambrian strata. ...-...-.--..------------ 315, 316
genera and species referred to, described.....-.----.------ 725-795
general stratigraphic distribution and number of Cambrian
genera and species of......------------------------------- 112
number of Cambrian genera and species of ee llile)
number of genera and species in monograph 113

number of Ordovician genera and species in monograph.... 113

shell structure compared with that of Orthidz 300

shell structure of 300
Billingsellide: (Cambrian), shell structure compared with that of

Ordovician Protremata.-.-.-.--.-.-.--..-.--------------- 300

INDEX. 821

Billingselline, classification of...............2----ese+--ce----- 321,325
genera and species referred to, described - 745-772
surface ornamentation discussed .................-.-------- 303

billingsi, see Huenella and Protorthis.

billingsiana, see Lingulella.

Billstaan River, Sweden, locality on.-.--...2.--.-..---2---------

Billy Creek, Wyoming, locality on...

Bilobites, classification of, by Ulrich ................-..----
muscle scars of, discussed by UlIrich
no Cambrian representatives.........-...--.-..------------

Biludden, Sweden, localities on the peninsula of ...........-..-..-

Birch Point, Newfoundland, locality near
Birmingham, Alabama, locality near....
Bisbee, Arizona, localitiesimear.....-......-.........-.-..--.- 14x, 358b
bisecta, see Acrotreta.
Bishops Mill, Tennessee, locality at..-...............-.-------.--
bivia, see Billingsella. :
Bjorkelunda, Sweden, localities at--....._-_..........-.---. 321u, 321v
Black Hills, South Dakota, localities in.......................-.- 17j,
17k, 88a, 164, 165, 167, 355, 355a_f
Black Mountain, see Montagne Noire.

Blackrock sUivaby locality Means). esas ese ae eee essen 3or
“Black shales”’ (Upper Cambrian), localities in.._..._- 304b, 304e, 304f

ATIET CLONE ees see ae eae for eee oe ae eee te 557, 559
Blacksmith Fork Canyon, Utah, localities in ........-.......... 31c-e,

31h, 311-n, 54a-p, 54y, 55h, 55n, 185z
Blacksmith Fork section, Utah, in detail, listing included and
correlated species and localities...--.-.-.-...-...-.......25.-- 148-153
Blacksmith limestone, in detailed section in Blacksmith Fork,

Utah, listing included and correlated species and localities... --- 150
Blackwelder, Eliot, acknowledgments............-..-.-.---.----- 12
ibipllographicmeferenceses eases see eee eee eee eee eee 14
speciesmamed for s—ciss see aate eee ceiee sane eee eee eae 453

Blackwelder, Eliot [Willis, Bailey, and], bibliographic reference... 26
blackwelderi, see Obolus ( Westonia).

Bland County, Virginia, locality in......-...........-..-..--...-- 47h

Blochmann, Fr., bibliographic reference...........-...-..--....-- 14

herminolopy; Olaan-sne eres eee eee nee neeeene aces eae 292
Bloomington formation (Middle Cambrian), in detailed section in
Blacksmith Fork, Utah, listing included and correlated

species and localities ....---.-----.---.-.-.-..--.......- 149-150

5h?, 31h, 311, 32x?, 54h, 54i, 54k, 54v, 55d?, 55n.
16, 89, 144¢

localities in..--..-
Blount County, Alabama, localities in
Blountsville Valley, Alabama, locality in... 2
Blue clay, in generalized section for Russia..-..........
Boda, Sweden, locality at......-.............-.
Bohemia, Cambrian species of, listed
generalized section of Cambrian and Ordovician in, listing
snecies|a.ndylOcaObles Seren eee ese e eee eae

124
localities in ...-...- 308, 303a, 303b, 303d, 303e, 303g—p, 345, 345a-1

species of Obolus from, listed. .--....-.......-.--......-..-- 379
bohemica, see Acrothele.
Boisdale, Cape Breton, localities near.... 3p, 10e-i, 13h, 160, 307a, 372b
Boisdale Road, Cape Breton, localities near... 10d, 10i, 10k, 10m, 372a
Bonar Spall OCA G ygIl CA Teper eels ee ee eee ee 350
Bonne Bay, Newfoundland, locality at..............-............ 314f
Bonneterre, Missouri, localities at and near........... 369a, 369c, 369¢
Bonneterre limestone (Middle Cambrian), in generalized section
for Missouri, listing species and localities................ 137
oeeibtites ile 3.25. chesresseeosssecacesecbosseenssosanas 11j, 14m
Borgholm;/Sweden, localities'at_----- 77) -2 222222 eee 8z?
309f, 310b, 310d, 310i, 310j, 3100, 310p, 320g, 390;
borgholmensis, see Acrothele.
Bornemann, J. G., bibliographic reference.............-........-- 14
GOES MENG! eH cogacccessooseosonsoreacedene Sesedeoncane
bornemanni, see Lingulella.
Bornholm Island, Denmark, localities on........_... 16h-1, 334, 334a-h
Borregaard, Denmark, localities at ........-. 16h, 16i, 161, 334a-d, 334h
Borstil, Sweden, localities in-............- 31lp, 31ly, 321, 32la-d, 3210
Borthwood, Wales, locality at............. 305h
Bostwick Canyon, Montana, locality in
Bosworth, see Mount Bosworth.
Bosworth formation, detailed section listing correlated species and

local tlesmar sett eei ee Senne eae Sea ae uae 126
resemblance to Algonkian Belt series mentioned........... 126

PB OF S{OT MiG ACOs CIDE oe) see ates = a miatete er ae eer ee rae 601
Classifica tioniofes-mm acess ta eee ae see eee ce 321, 324

compared with Acrothele (Redlichella)..............-- 663,

TECH TCT espe nea Geee kL ae ricci ac neal GapBeeceeare 572

Botsfordia—Continued.
compared with Obolella............--..---.----..-- 587, 588

Yorkia ? washingtonensis...-.-+..-------.----- 613
evolution discussed 319
evolution of 317
general geographic and stratigraphic distribution of

the/speciesieferrcd: [=a e eee eee ee 104
general stratigraphic distribution and number of Cam-

brian species and varieties of............-......--.. 110
mentioned sc a4 2a eae eee See sae a 605
MUISCLESCALSCISCUSSC Case eet eee ee 312
number of species of, in different types of sediment.- 160
pedicle tube discussed 314
reference to, of Botsfordia barrandci discussed. ......-. 603
surface ornamentation discussed.......-..-.--.-.--- 301, 302
tvpelspecies|Obolius) pulchenaasesee eee ee ee eee ee eee 601
vascular markings discussed . - - 311

0arrandeyad ESCri bed ene ae eee eee ee eee 602
GISCUSSEG <2) )4 bese aes aoe a Bes ae Se Nereis oe ore 633
general geographic and stratigraphic distribution tabu-

Neatedets ac 2k Sakae setae ae Sea re ae ete gaa Rt ep ae 104
surface ornamentation discussed . 302
type specimen) figured...2--.....-._-_-.2.-- Pl. LVII, fig. 7

Celera described 2/n- sen eee ae ret ee eee eee e ee eee ee 603
cCardinaliarea discussed esse see eeeteeeaeeeeeeseeeeee 305
compared with Acrothele matthewi........-.-..------- 632

FAICHOLLELE MILI Cee nee ae eee ee ee eee 650

LOR OMT POOUG Us ~ a nececoasessesone2seseccos 608

Obolusielegans sec ke sath sae =a eee eee 391

Schizopholis rugosa 609
general geographic and stratigraphic distribution tabu-

lated tt... .2th sees: sec cee aes 2 sate eae wees See enter ae 104
stratigraphic position mentioned..-........-.--..--.- 318
surface ornamentation discussed .....-...---------- 301, 302
type specimen not figured.

(GAMO, COSC Ceo seo sce 53050 s2Gdss ses acueascssctoaness 605
cardinal area discussed -.-........------:------------- 302
compared with Acrothele matthewi..-.-.-- 632

Acrothele (Redlichella)......-.-.------ ae 663

Acrothele (Redlichella) granulata - 602, 663

TB O18 {0T0) 0102210) eee eee 604

Botsfordia pulchra...-.-. Ny Sen epee oe te te 601, 608
discussed tees oo eee eee eee ee esece nee eee ere 601
general geographic and stratigraphic distribution tabu-
IHG Je dearosesqocndesscosoopesenes=baseUcesanesse 104
surface ornamentation discussed...........---.------ 302
type specimen not figured.

pulchra, described 607
cardinal area discussed - - 305
compared with A crothele bellapunctata.-.-.-....------- 633

Botsfordia ? barrandei.......--..-------.-------- 603

FB OLS] ONC LOC 220 ee eee eet 606
Botsfordia granulata.....----------------- 601, 606, 607
CEUIUGUVELLONT CLL eo) sere tatn eae ee ae eel 529

Micromitra (Iphidella) pannula.-..--...-------- 602
GSC USC Gee ene ee ee eee 602
general geographic and stratigraphic distribution tabu-

Teel ns cockecscecoo toons sess secese esos zefoasscoss 104
muscle sears discussed.....-.------------------------ 312
surface ornamentation discussed.......-.-.-...------- 302
type specimen not figured.
botinicus, see Obolus ( Westonia). :
Boundary Brook, Cape Breton, locality on.........--...--..----- 344e
Bow River group, detailed section listing species and localities.... 130
Boxelder County, Utah, localities in.............-.-.---.---.---- 30u,

3ly, 32c, 32n, 32p, 32x, 32y, 33j, 33t,
34m, 34q, 54k, 54q, 54r, 55e, 105x, 329

Bozemanj Montana, locality near..........--......--------------- 160a
Bra@hacdetined sa ee cateee ee eee tebe mccese acne eee ate ae 292
iBrachiocceles| defined esse eases seer eee ae eee 292
AN wa Oe 55 emoar es seonebeesabeonscessecosScooEsaS 3874
vessels) of, Shown in figures: :-.----------- 2. =e ee 374
Brachiopod, most primitive - 316,318
GOR SON Alle ~ 25 Sanden esesscooorenasoueEstesse gseacgssuRe 316

simplestiformies sah asee ates e eet cess foe ee eosin eels 327, 328

iBrachiopodabiblioprap liye espe s-e eres eases eee een 13-26
sabes -. 321-326

== 292-296

distribution in Cambrian strata...............-.---.----- 315-316
distribiitionitables#=asseeeeer snes a eeeseecine eee sees 98-159

822 CAMBRIAN BRACHIOPODA. /

Brachiopoda—Continued. ?
evolution Sy... 316-320

- 159-160

161-291
Bane asses srasocss 316
percentage of genera and species included in Obolidz, Acro-
tretide, and Billingsellidze aq lle
setee of, figured 362
Shellistructure:). .susce coat eee Sas cee see ee 296-300
structural features 300-320
summary tables... - - 110-113
Synonyanyatableweessccice = ae eee ee eee ere 27-98
terminology: <2 sc 2ssn5. 552s soe oe Oe ee eee ene 291-296
Braintree, Massachusetts, locality at..............-.------------- 5
Braintree slate (Middle Cambrian), locality in...............----- 326b
“ Brandschiefer” (Ordovician), in generalized section for Russia,
listing species and localities. .....-.....-.---...--...------- “143
localitysitee= se eemeeeee eee
Brantevik, Sweden, locality at
Bras d’Or Lake, Cape Breton, localities near__-.............-.... 100,
10r, 13i, 13r, 307j, 325; 325b, 325c, 372d
Brecknockshire, Wales, locality in-...........-..--.-..---.------ 366r

bretonensis, see Obolus (Palzobolus).
bretonensis lens, see Obolus (Palzobolus).
“Bretonian” (Upper Cambrian), generalized section of, listing

Species aNd 1OCaltleS = ateeeoe= == eee eee ee 131
ieenilttiny Will -enchsoecassoscetegsass2o2se0s: ssesseee2 sSese2s 13q

See also Divisions C2 and C3.
Briceville quadrangle, Tennessee, locality in-.-.-.-.............. Wd
Bridger Range, Montana, localities in. --.--... 147a, 148a, 151, 15la, 152
Brigham, Utah, localities north and east of.--.-.-.......- 8ly, 32c, 32n,

32p, 32x, 32y, 33j, 33t, 34m, 34q, 54k, 54q, 547, 55e, 105x, 329
Brigham quartzite, in detailed section in Blacksmith Tork, Utah,

listing included and correlated species and localities. ... 152-153

line between Lower and Middle Cambrian in.............. 153

Bristol, Tennessee, locality near..........------------------------ 2z,

Bristol County, Massachusetts, localities in................- 326a, 326d

Bristol quadrangle, Tennessee, localities in---------........... 2z', 374¢

British Columbia, Cambrian species of, listed-..-............... 114-119
detailed section for, with included and correlated species

AIG EMNICS 3 a0 so cece ssoonssereebasessecusoacs uses 125-131

localities in. l4s,

35c, 35f, 35g, 35h, 35k, 57c-g, 57j, 57k, 57m, 57n, |

57r, 57s, 57y, 58f, 58j- 1, 58p, 58r, 58s, 58z, 60b, 306
Mount Bosworth section, in detail, with included and cor-

related species and localities.........-.-.--..-.---...... 125-131
Brogeger, W. C., acknowledgments....---------------..-.....:.-.- 12
bibliographic MAPMTCES. = scorseoossecssatscestsceccessscoos 14

(Bréggeria), see Obolus (Broggeria).
Bronsil shales (Upper Cambrian), in generalized section for Eng-

land, Scotland, and Wales, listing species and localities... 135
HO CAUINTES Ta, - ses ced ockoeeezcenscer2eses + ger2cescesrcoo 304, 304a
Brown’s quarry, Prairie du Sac, Wisconsin, locality at........... 85a

Bruachaig River, Scotland, locality on
Brunswick, New York, locality mear..-........-...-.........-...
Bryn Melyn, North Wales, locality at...-----.......------------.
Bryograptus slate (Upper Cambrian), in generalized section for

Sweden, Denmark, Finland, and Norway, listing species

and localities - ..- 145
IMAM has obecwescogesbet oasshodsevssauessess seoseSEsoes 3092,
systematic reference discussed. .....-...-..--......--..--... 98

Buch, C. L. von, bibliographic references. ---- 14
Buchava quarry, near Skrej, Bohemia, locality at.-...-.........- 345d
buchi, see Keyserlingia.

Buck Creek, Alabama, locality near........--..-----.------------ 56c
Buckingham Ford on Hollis Creek, Tennessee, locality at_......- 1l7c
Buffalo County, Wisconsin, locality in................-.----.-.--- 328c

Buffalo Creek, Montana, locality near
Buffalo Creek, Virginia, locality on........--

Buffalo Fork Peak, Wyoming, locality near...............-..---- 302v
Buffalo Mills, Virginia, locality near-...........-.----.------.---- 92b
Builth, Wales, locality near

Bull Hill Cottage, South Shropshire, England, locality at........ 304k
Bull Run, Tennessee, localities in-.......-........---.-- 107, 107a, 107b
Bullwhacker mine, Eureka district, Nevada, locality near. _..--.- 64
Bunker Hill, Tennessee, locality on.........-.....--.----------.. hq
Burgess, Canada, locality at........-.-.--.-- =. 392
Burgess Pass, British Columbia, locality near. ...-.-.--.......--- 35k

i
{

Burgess shale, mentioned.-.......-...-....-. eee een Oe

Burgess shale member of the Stephen fontation! ‘(Middle Cam-
brian) locality inlesesass 5 eee aaa eae re Sac 35
Burling, Lancaster D., acknowledgments es 13
work on Comair Ondariaaa boundary in British Cams. 125

Burling, Mrs. Lancaster D., species named for.....-.....-.-.-.- cay CES
Burnet, Texas, localities near.......-..............-.-..-. 67, 67c, 67z
Burnet) County, Wexas localities ee 67,
j 67c, 67z, 69, 70, 70a, 70e, 71, 353a.
Burr, H. T., bibliographic reference 15
Butts, Charles, species named for...-.-----.-.--....-...-.-------- 484
buttsi, see Linguiella.
Caballos Mountains, New Mexico, localities in.............. 327, 327a-c
Cable Mountain, Montana, locality on.-..................-..-...- 340e
Cabo Busto stage (Ordovician), localities in_............... 350a, 350b
Cache\ County. WUitahe Ocal ties ine sees eee ene 31c-e,

31h, 311-n, 31z, 32d, 32e, 54a-p, Say, 55h, 55n, 55t, 185z, 3298
czlata, see Botsfordia.

Caer-fai wWaleswlocalitvatseee epee nese eee enone eee eee eee eee ae aee 366¢
Caerfai group (Middle Cambrian), in generalized section for Eng-
land, Scotland, and Wales, listing species and localities... 136

localities in 318i, 366¢
Cairn Burn, Scofland, locality at........................---.-...- 316b
calcifera, see Syntrophia.
“Calciferous sandrock”’ (Lower Ordovician), Lingulella (Lingu-

lepis) acuminata in, discussed.........-.------------------ 547
localitiessin soe oe 2G sec Paes Seen Soe 319t, 319u, 338u
men WOM ed reel eae scaee eee eee eee eee ee eee 509

“Calciferous sandstone,” mentioned................-------------- 551

Caledonia, Missouri, locality near...................-....---.--..- 369d

California, Cambrian species of, listed 114-119
localities in......... 7, 8b, 141, 14n-p, 53, 176, 176a, 178a, 312, 312a
species and localities correlated with those of Nevada..... 137-138

Callaway, C., bibliographic references............-..------------- 15

Calls Hort Ural locality Chie ese seas eee ee 329

Camarella, compared with Swantonia.........-..--...---.--.----- 797
“calcifera,’’ compared with Clarkella montanensis.....-..-- 810

compared with Stricklandinia 798

mention edWees eee5- ee eee 798

volborthi, compared with Swantonia antiquata..........-..-- 797
cambria, see Schuchertina and Syntrophia.

Cambrian, number of genera in divisions of.......--.-....--....- 316
sedimentation in Cordilleran region mentioned_.....-..... 148
species of Asia, zoologic list of, giving distribution by coun-

WAC Ss phos oorcnssocssemesoomseosmbssacodes yaseesedoR" 121-122
species of Europe, zoologic list of, giving distribution by
@PEANNES. ~~ 5522-525 32scoSeoss aos sosaessssssesnaaese2= 120-121
species of North America, zoologic list of, giving geographic
distribution by States and geologic provinces .........- 114-119
See also Lower, Middle, and Upper Cambrian, and Passage
beds.
Cambridge, New York, localities near-....- foe aoe eo eee

Cambridge quadrangle, New York, localities in
33, 33b, 36, 36b, 37, 37b, 39a, 43, 43a,
45a, 338c-¢, 338i, 3381, 3380, 338p, 338x
Camerella, mentioned .--.------- =. == 22-2 en
“antiqua,” type of Swantonia
“sp. Shumard”’ discussed ----.------

Camlan, North Wales, locality at..........

Campbell, M. R., bibliographic reference. .-......-------.--....- 15
SPECIES 0 HI CUNO Ue ieee eee eet eee ee ee eee 802

campbelli, see Syntrophia.

Camp Creek Canyon, see Queens Canyon.

Canada, see Alberta, British Columbia, Labrador, Ontario, Que-

bec, New Brunswick, Newfoundland, Nova Scotia, and
Cape Breton.
Canadian Pacific Railway, Canada, localities on line of....-.....- 14s,
35c-h, 35k, 57c-g, 57j, 57k, 57m, 57n, 57r,
57s, 57y, 58f, 58i-1, 58p, 58r—t, 58w, 58z, 60b

Canal Grande, Sardinia. localities at........-....... 354, 354c, 354e, 354f
cancellata, see Acrotreta.

Cane Creek Mountains, Alabama, locality in-...-......-.-..-.-.- 137
hin ESS, Wiens MoS Bite 26 e ho eee see eceecocesenesans 84r, 34¢
cania, see Lingulella.

Canon Ferry, Montana, locality mear........-..--...-.--..------- 9h
Cantabrian Mountains, Spain, locality in... 350
Canyon quadrangle, Wyoming, locality in... 4j
Canyon Range, Uitah} locality im----- =~ <2 a= 33

INDEX.

Cape Breton, Cambrian species of, listed 114-119
generalized section of Cambrian in, listing species and locali-

hieSme Rae een wee een eee Fey eet es ee eh 131-135

Hocalitieshin ieee ee ee ac yse ha use dee eee see nea eos 3h, 3i, 3n-q,

8d, 10c-i, 10k-p, 10p’, 10p’’, 10q-t, 11z, 13d, 13d’, 13d’’, 13e-i,

13k, 131, 131’, 18m, 13n, 13n’, 13n’’, 13p, 18p’, 13q, 13r, 13t,

13t’, 138t’’, 160, 307, 307a-j, 325, 325a—c, 344, 344a-o, 372, 372a-f

Cape Rouge, Quebec, locality at................-- 319¢

Cape Vidio, Spain, locality at. .

Caradoc limestone, in generalized section for England, Scotland,

and Wales, listing species and localities...............--- 135

Carbon County, Wyoming, locality in.....-........-..._......-.- 340¢
Cardinal area, defined 292
CISCUSSEM ns Poi eee et Maaoa see ge seoe Ecc pone see eee acne 303-305
Showmbinehi cure sayitet el e ter eh 8 Le ae eR eee 374
Cardinallextremities, defined) ==sa= a2 e ssa eanee eee acces ee 293
Cardinalemusclescany) detinedsesssee semen oe oe eees eee eee een 293

Cardinal Peak, Montana, localities nes
(Cardinaliprocess; defined eeene reset eee ne eee PE ree Enea eres
GHOSE. ccoseeasooessessos 3 Pe aaa. Seana eee
Cardinal scar, development of... .
Cardinal slopes, defined -.-.-...
Carillon, Quebec, locality near

carinata, see Acrotreta.
Canlforswoweden localitysatesssee sete een eee er eee ee eeeeeee
Carlton shore, New Brunswick, locality at...
Carnarvonshire, North Wales, localities in.-..........-..+.--.---- 305a,
305c, 305d, 318a, 318b, 318s, 318t, 366d, 366e

293,

Carnedd Filiast, North Wales, locality at..............-.--.-.---- 366d
Carnegie Institution of Washington, acknowledgments.......-.-- 12
Carpenter, W. B., bibliographic reference.-........-.---- Pea ara se 15
Carter County, Oklahoma, localities in...-.......-.. 12k, 12m, 12n, 12p
Cartersville Georgia, localityamean ss sees se ese se ase eeee eee a neeee 96x
Cartersville quadrangle, Georgia, locality in. - 96x
Cascade County, Montana, localities in. .....- 4x, 5f, 5k
Casper, Wyoming, locality near.............. 3020
Castle, Alberta, localities near. -...............--.--- 58i, 58t, 58w, 60b
Castle Creek, South Dakota, locality on........-......-.-.------- 355b
Castle Mountain, Alberta, localities on... .. 58i, 58t, 58w
OT OTS AAS BSA ON= - h- S os se sacs ss ssosesososeqesees 127
Cathedral limestone, detailed section...........-..-..----- ----- 128-129
Catons Island, New Brunswick, localities on_..........-- 2y, 301f, 308d
<c/@aused,77 Penericirelerence! GISCUSSCGs ase eee ee eae 330
Cave Spring, Georgia, localities near. - - . 96b, 140a, 140c, 362a
Caye/Spring; Utah) locality mear- 2-2 2222-222 2--2.--2------------ 15d
Cedar Bluff, Alabama, localities at-_...........--.------.-.-:-- 90a, 91
Cedartown Road, Georgia, locality on the._.......-_...-.-.-.-.-- 96
cedens, see Lingulella.
Cefn Cyfarnedd, North Wales, locality at...............-..-.....- 305j

celatus, see Obolus (Schmidtia).
Cement Creek, Colorado, localities on.-.-.. Aphskecaosemaeaooe 335a, 360b
Centennial Eureka mine, Tintic special «juadrangle, Utah,
Tea Wn TEE Sos sccecconqesesnesecossasedasedsseccepesone 34s
Center, Alabama, localities mear..................---.--.------- 90, 90x,
92x, 93, 93a, 93n, 980, 93x, 94, 94a, 940, 94x, 94xx, 95a, 146

Center road, Alabama, locality near the........-....-. 95a
Central (adductor) muscles, attachment in Orthide -.. = tO
COTE eos ocaned bocéoned se qoncsapp sassSosacconsoonsasa0nue 293
SOON ad Te) TGP = os oo ececosesescnedssss sos yessenesessooe 374
ceratopygarum, see Acrothele.
Ceratopyge limestone (Passage beds), Hoorthis daunus characteris-
tic of, to the exclusion of Hoorthis christianiz .....-...--.- 775
im generalized section for Sweden, Denmark, Finland, and
Norway, listing species and localities. ..............-..- . 144
localities sineaemere earner eee es tee eee eset 8x, 309, 310, 310j,
310x, 320w, 323, 323c-h, 323j, 323z, 386, 390, 390e, 390f
WAG MHA 2 ssosscssasescossdo=sesscuees 424,515, 710, 712, 741
systemic reference discussed.......--.----.----------------- 98
“Orthis christianie”’ from, likely Poorthis dawnus .......-.- 776
Ceratopyge limestone and shale, Hoorthis wimani found in both... 775
Ceratopyge shale (Upper Cambrian), Hoorthis christianiz character-
istic of, to the exclusion of Hoorthis dawnus ....-....------ 775
Ceratopyge slate (Upper Cambrian), in generalized section for Swe-
den, Denmark, Finland, and Norway, listing species and
TERNS. 5 Gsacsceonsssdo os coooosSeresspsbesesssrassso5e2 145
localities in 310d, 310r,
310s, 32le—n, 323a, 323k, 323x, 323y, 390c, 390i, 395x?
WECMNOMA -osess0 saesssonsasecososcpodsessenserecs 424, 425,710

systemic reference discussed......--.----------------------- 98

Cerro Cuchillo, New Mexico, locality near............-...--------- 327b
Champlain, see Lake Champlain.

Champlain Canal, New York, locality on.
Changhia, China, localities at and near

C20, C22, C23, C26, C28, C36, C68

Changhia limestone (Middle Cambrian), localities in............-- C22,
C23, C26, C28
Chapman, E. J., bibliographic references. .............----.------ 15
Chapple Arm, Newfoundland, localities on.............-.--- 6g, 6h, 314
Chapple Cove, Newfoundland, locality near...........--.....---. 5t
Chase Creek Canyon, Arizona, locality in 358
Chateaugay, New York, locality near_.-..-......---.::---2.------ lll
Chateaugay Falls, New York, locality at........-.......-..--..-- 338u
Chatham), New. orks locality mea ss==s sees s=e = eee ease eres 32a
Chatham, see North Chatham.
Chaudiere River, Quebec, locality on..............-..------.----- 220a

Chaumitien, China, localities at and near_......-.......- C36, C45, C68

Chaumitien limestone (Upper Cambrian), localities in...._.__..- C36,
C45, C54, C56, C68

“Chazy formation”’ (Ordovician), localities in-..-...--.-- 319n-p, 392h
Checker Beach, Rhode Island, locality on............-.-.-...-.-- 34384
Cheever’s ranch, Wyoming, locality near_...:.........- ... 302u
Chél Hill, Salt Range, India, localities at_. ..- 357b, 357d
Chepultepec, Alabama, localities near...............--.--..-- 139a, 140
Cherokee; Rexas’ localitiesmears == es. sss - see 2 ee oe eee eee 14g, 141
Cherokee County, Alabama, localities in--......_...-..- 90, 90a, 90x, 91,
91x, 92x, 93, 93a, 93n, 930, 93x, 94, 94a, 940, 94x, 94xx, 95a, 146

Cherry, Creek, Nevada) locality mean: .- 2222202222522 0252-5---seeee 4)
Cherry Creek Basin, Montana, locality near..................-.-- 149a
(@hiliditm define dae een ee essere eer =n nee sso ZAR
China, Cambrian species of, listed. .......-......- -.- 121-122
localities in (Lower Cambrian)............---- C3, C17, C20, C32’
localities in (Middle Cambrian)..................-.......- Sa, (onl,

C2, C4-7, C9, C10, C12, C22, C23, C24, C26,

C28, C32, C37, C57, C62, C63, C70-72, C75

localities in (Upper Cambrian) 332,
332a, C36, C54, C56, C61, C64, C57, C68, C74

species of Obolus from, listed.........-......-...-..-...-..- 379
See Liaotung, Shansi, Shantung, and Shensi.
chinensis, see Obolus.
Chippewa County, Michigan, locality in...................-...... 330
Chisago County, Minnesota, localities in...............---........ 82b,
82c, 97b, 97s, 339d, 339]
Chisholm mine, near Pioche, Nevada, localities at..............- 7k, 31
Chonpinghien, China, localities near....-.......... C32, €32/
Chouteau County, Montana, locality in -...........-...---.------ 302z
Christiania, Norway, localities at and near 8x,

8z, 9f, 323, 322a, 323c-h, 3231-q, 323t, 323v-z
christianiz, see Eoorthis.
Christianstad (province), Sweden, localities in.........-.........- 8w,
310h, 3101, 320c, 320f, 320i, 3200, 320x, 321u, 321v, 321y, 3900
chromatica, see Obolella.
chuarensis, see Obolus (W estonia).
Chuar Valley, Arizona, locality im=*--------- 22-2 tte
Chudleigh, Esthonia, Russia, locality at.. 337g
Chura Canyon, Montana, localities near.............-..... 151, 15la, 152
cincta, see Lingula.
cingulata, see Kutorgina.
circe, see Quebecia.
circularis, see Acrotreta.
(Girne ilatonyg Sy Ste noys CLS CUSS C0 lene e eee eee 311-312
Clark, W. B., and Mathews, E. B., bibliographic reference... ..... 15
Clarke, J. M., acknowledgments
bibliographic references ..........--
genus named for....--....-..-...--
GROENTEVANG! WP. soa zde dances Seen pocseszcecsesecoteossness

Clarke, J. M., [Hall, J., and], bibliographic references ..-....... 18
clarkci, see Lingulella.
(Cli Alli, COI MVEL << ogee s2cisssed 222 233s ssedecg sostessstdeaeeoss 809
classifi caiwent Osa eserane ee ears cree ea 321,326
cruralium mentioned 309
Ey OlUUIONCISCUSSed epee ee see See ee eee ee ete are 320
EV. OIOMION SAE ose cil = a2 So eee ee eee ee 317
general geographic and stratigraphic distribution of
tihe\speciesmefermed) tore 45 4-eaeee ieee eee eee 109
number of Ordovician species and varieties of......._.. 113
number ofspecies of, in different types ofsediment.... 160
Spondiylumaiis cussed eae see see ee Seen ee eee 307
type species ‘‘Polytechia montancnsis”’ . 809
(Winichton!spondy] iim Syeeee ese ee ee eee eee eens 308

B24. CAMBRIAN BRACHIOPODA.

Clarkella montanensis, described -....--...----------------------- 810
general geographic and stratigraphic distribution
tabulated. ecclissi ae ae eeteeterete 109
type specimen figured...........--...--.--. Pl. CIV, fig. 2a
clarki, see Dearbornia.
Classification, importance ofshellsubstancein.-..-..........-.... 297
importance of surface ornamentation im -.._....---.--------- 301
Clayton County, Iowa, locality in-.-----.---.-----:-.-...--.-..-- 34la
claytoni, see Acrotreta.
Clayton Valley, Nevada, locality near. --...--...-.----.---------- 175
Cleveland, Tennessee, locality near 128

Cliff House, Devils Lake, Wisconsin, locality near.....-..-------- 81lo
Clifton quadrangle, Arizona, locality in
Clinton, Tennessee, locality near -.---.---------.-----------------
Cliothyris, cardinal process discussed. ...------------------------:

Clitambonites, compared with “‘ Orthis pepina”’ 739
compared with Protorthis co! 163)
pedicle tube discussed... . - -, 315
pseudospondylium discussed...--...--.-.---.-------.------ 307
Wrichvonyspon diy lias eee sees eee 308

Clitambonitidae, compared with Cambrian Orthidz by Ulrich.. 308
SU iin aVorss 5 Or iy nae ee eee 308

Coal Creek, Tennessee, locality near.........---------------------
Coal Hill, England, locality at..............-....-.-.- :
Coal Pit Bay, Ireland, locality at..........-....-.-

Cochise County, Arizona, localities in.......--..-

Codorus Creek, Pennsylvania, locality on

Cog Hill, Tennessee, locality mear.....-.--..---.----------------- 1284
Cohoes quadrangle, New York, localities in 27a, 367b
Coldbrook, New Brunswick, locality at......--.------- 301¢
Coldbrook (Middle Cambrian), detailed section of, listing included
species and localities...........-.-..-..--.---------------- 135
localitiestink= 2s. ss<--ee 2s Sea ncentcemer seen ee eines aa 13k, 344£

Cold Creek, Texas, localities on.--.-..--.--------
Coleoloides cf. typicalis, association mentioned - -- 328
Collen, M., species named for....-.....---------------.-----.----. 641
colleni, see Acrothele.

collicia, see Lingulelia.

Colorado, Cambrian species of, listed.........---.-------------- 114-119
localities in 8g, 186, 186a, 187, 335a, 360, 360a-i
note on stratigraphic position of localitiesin...........--.--. 135
coloradoensis, see Billingsella. r
Colorado River, Arizona, localities on.....-.--.-.---------------- 17e,
73, 73a, 73b, 74, 74b, '74c, 74d, 75
Colorado River, Texas, locality on.........--.--.----------------- 14r
Colorado Springs, Colorado, localities near..-.-..-.-..-------- 360, 360d
Columbia County, New York, localities in...-......-. 29, 32a, 44b, 338b
Columbia County, Wisconsin, localities in..........-..---- 86, 328i, 328e
columbiana, see Philhedra.
Comanche County, Oklahoma, localities in-.-......-.-.--- 9p-x, 9z, 12]
Combs Peak, Eureka District, Nevada, locality on. -..-..--------- 59
Comley, in generalized section for England, Scotland, and Wales,
listing species and localities...........------------------- 136

complexus, see Obolus.
compta, see Nisusia.
Conasauga limestone (Middle Cambrian), localities in_-......-.. . 560,
56q, 56u, 90b, 90c
Conasauga (Coosa) Shale (Middle Cambrian), in generalized sec-
tion for Tennessee, Georgia, and Alabama, listing spe-

Giles ae NOMS Gan csccbase sons Sbeecesssseebscceessues 147
(OHMS MH, - = SoA scoose sso seossee soos 16, 90, 90x, 91, 92x, 94a, 146
MAGMUMOME\E 3 — soe cgogans cqoetecepeesosessoe oes sasaagz=z0 505, 521

concentrica, see Acrotreta.
Conception Bay, Newfoundland, localities on ..........--- 1, la, 2, 2a, 3,
5p, bdr, 5t, 61, 6n, 6r, 6u, 6v, 41, 41a, 114, 114a, 114b, 314a, 314e, 314h
section near, listing species and locales see eee aaeee 140-141
Conchidium, cruralium mentioned -....-.-..------------ 309
790.

Conchidium nysius, compared with Billingsella exporrecta..
concinna, see Lingulella. :
Coniston, England, locality at......-..-.-....----------=--------- 304n
Coniston (Bala) limestone (Upper Cambrian), in generalized sec-
tion for England, Scotland, and Wales, listing species and
IG@PINES Saeco)! sossoestsnscecconososseorcossssossesaas
Toealltlisy WM. . . so seSd- seed cso see coco ese asssss2sseessse=5
Conococheague limestone (Upper Cambrian), locality in.
Conocoryphe elegans, association mentioned... -.....--------
Conocoryphe exsulans zone (Middle Cambrian), in generalized sec-
tion for Sweden, Denmark, Finland, and Norway, listing
species and localities......-..--------..--------.--- peanee 146

Conocoryphe exsulans zone—Continued.
localities hamyee ese aee cee ere aeeatele te eeteeteaie eretaeetette 16i, 334a
See also Exsulans limestone.
Conocoryphe trilineata, association mentioned
Conrad), DSA) bibliopraphicireferen ce = prea naar ee seminal tele 15
contraria, see Orbiculoidea.
conula, see Acrotreta.
convexa, see Acrotreia and Lingulella winona.
Coopers Lake quadrangle, Montana, localities in--..........-..-. 35, 5j
Coosa River Valley, Alabama, localities in.........-.. 90x, 92x, 94a, 145
Coosa shale, see Conasauga (Coosa) shale.
Copenhagen, see Geneva.
Copper Ridge, Tennessee, localities on._...-.-.
coriacea, see Acrothele.
Coronado quartzite, localities above................--------.---- 90, 358
Coronatus zone (Middle Cambrian), in generalized section for
Sweden, Denmark, Finland, and Norway, listing species
and localities
Jocalities)inij2.s25 S244 jase eae aie see see eee ee eee
corrugata, see Finkelnburgia osceola.
costata, see Acrothele prima. . ; e
Cottonwood Canyon, Montana, locality near
See also Big Cottonwood Canyon.
Coulouma, France, localities in.............-..-.--------------

107, 107a, 107b, 1070, 107u

Cound-Moor quarry, England, locality near.........-...-.....--- 304i
Courtney Bay, New Brunswick, locality on...........--.-.---.-- 30ly
Cowan Creek, Alabama, localities on. 93,930, 93x, 94, 94a, 940, 94x, 94xx, 95a
Cow Head, Newfoundland, locality at............-..-.--.-------- 314¢
Coxsackie quadrangle, New York, locality im_.............--.-..- 338

GraipheadScotlandslocalitygat sees esee See e eee eee
Craigs Mountain, Alabama, locality near- .
Craig-y-dinas, North Wales, locality at...........-....-..--------
Crane, Agnes, bibliographic reference..........------------------

Cranialzlia, compared with Philhedra columbiana.. 724
* Crania unguiculata,’’ type of Siphonotreta - é sa (ie)
Craniacea, classification of.........--.----- ‘321, 325
distribution in Cambrian strata.........-.-.-.-.---.------- 316
genera and species referred to, described. ...........-..------ 724
Craniide, canalsystem mentioned...............--..-.--------- 312
Classificatiomiofis22 8s 3-423. Shas senca- cen ee ee eee eee 321, 325
distribution in Cambrian strata............-.-------------- 316
genera and species referred to, described..........--....---.. 724
general stratigraphic distribution and number of Cambrian
genera and species of..--..---.------- 5. -- 22-5 eee we 112
number of Cambrian genera and species of... .-.--..--.----- 112
number of genera and species in monograph..........-.----- 113

crassa, see Obolella.

crassa elongata, see Obolella.

crassus, see Obolus (Schmidtia).

crenistria, see Micromitra (Paterina).

Crepicephalus texanus, association mentioned............---------- 692

Cressage, England, locality at.........-.- thi Aas hoo eee ee 304i
Crested Butte, Colorado, localities near.............---- 335a, 360b, 360c
Griccieth, North Wales, locality at.........-..-.--.---.---------- 318a
Cneket Range; Utah) localitysinhs sees e see ses eee eee eee ets 33r
Cricket Spring, Cricket Range, Utah, locality near..........--..- 33r
Crow Creek, Utah, locality on 33n

Crowfoot Ridge, Gallatin quadrangle, Wyoming, locality on. 302b, 302¢

Grune defined seme seen eae seeneee 293,
Cruralium,, defined\.5 2s. 22- ss2ececskacee ose cee eee pee eee aes 293
AISCUSSEd Ho. coh ine See ee Aaa See ee eae eee eee 309
Cruziana, association mentioned 3 359
Ctenocephalus matthewi, association mentioned .......---.-.--- -- 498
Cumberland County, Pennsylvania, locality in ~» ASE
Cumings, E. R., bibliographic reference................-..----.--- 15
cuneola, see Lingulella.
Curramulka, Yorke Peninsula, South Australia, locality at-...... 315

Curtice, Cooper, genus named for.....-......--..-----------------
Cunticia; described. s-7. 222 a2 pe asec ee ee eee
classification of.........-
compared with Dicellomus. .

Micromitra.....---

OOS he. Saas eee es See eee es

Rustella 370
delthyrium discussed - a 318
6yolutiondiscussedaes= esses ee eee ees eee eee 318
CHOMMO NOS. es aegecseedbeessecoscesstaszecosaens 317
general geographic and stratigraphic distribution Ss

the speciesireferred to. 2. <2. -.--- 2 =< - =r =e = : 99

INDEX.

Curticia—Continued.
general stratigraphic distribution and number of Cam-

brian species and varieties of.................-...-- 110

mentioned sss joe jes ee eee eee ne eee eee eee 369

\ number of species of, in different types of sediment. 160

AA DMT CONGR bs oe oscosasdoobaesascdeanseessousoseee 369
general geographic and stratigraphic distribution

tabulated sar caine eee see eee maser ee noes 99

type specimen figured ...._..--_._-...-...,.---- Pl. I, fig. 2

(Cunhichideeyclassificanioniofes-eeeee see eeeee secre eee eeeeere 821, 322

distribution in Cambrian strata .................--.----.-- 316

genera and species referred to, described - - . .-- 369-370
general stratigraphic distribution and number of Cambrian

generayand speciesiOlwee- ses eheeeee een eee eee ee eran 112

number of Cambrian genera and species of.............---- 112

number of genera and species in monograph. - gaare: HIDE
species referred to, described ...........-....------------- 369-370
curvata, see Acrotreta.
Custer, South Dakota, locality near..................-.-....----- 167
cyane, see Obolus.
Cyrtia, reference to, of “‘Acrotreta ? costata” ........-...---------- 674
(COPRRTTOS (GUND Hy HAO URNS. 4 ian cdsenbossate sesanospescoossae 468
Czerhowitz, Bohemia, locality at..............-..---------------« 303j
Dakota, Minnesota, locality near -- 84s
Dalarne, Sweden, localities in... . 8y, 9e, 310n, 3901
Dale, T. N., mentioned............. 409
Dall, W. H., bibliographic references 15

Dalman, J. A., bibliographic reference................--.-------- 15

Dalmanella, classification of, by Ulrich. dee G03
comparedawitheeofontiiseeeeeneeeeeneeeee reer eeeaeas 739

muscle scars of, discussed by Ulrich......--..-.------ 308

no Cambrian representatives...-........-.- 320

reference to, of ‘“Leptzna melita” discussed - - - - - ac Wt

muiltisecta, shell section figured .-......-..-.-..---- text fig. 9, 299
parva, shell section figured.........-.-.-.---.---- text fig. 10, 299
subzquata, compared with Orthis tricenaria by Ulrich....... 308
muscle scars of, discussed by Ulrich 308

Shellisechiontignuredsese-seeeeeeeeeee ee eee .- text fig. 2, 299
subequata group, compared with average Cambrian articu-

JEU oy AU had aleewe cer ut eeuneen Saeonnc Sesto GseasoouecRng es 308
damesi, see Lingulella.
Danaher Creek, Ovando quadrangle, Montana, locality near....-. 4we

Dane County, Wisconsin, localities in.-..........-- 85x, S85x, 85z, 328p
Danish Flat, Bear Lake County, Idaho, localities near......... 55c, 163

Danzig, West Prussia, locality near 386d

Darton, N. H., species named for 455

dartoni, see Obolus ( Westonia).

daunus, see Eoorthis.

Davidson, T., bibliographic references................-.--.------- 15,16
Speciesinamedvoners-s-eesee eee eee eeeees 489

“‘Davidsonella,” discussed - - - 565
*‘Tinguloides,”’ discussed . g 565
Gaim,” CSGWSSEC |. oo Jeno Seoomaeseeeosooseoseoseonsaozcos A

davidsoni, see Lingulella.
Davisyee ees pip hoprap hic ne leren cess er seer ele ae ene eee eee 16

species named for 491
davisi, see Lingulella.
Dawson, J. W., bibliographic references..............-.----.----- 16
Dawson, William E., acknowledgments...............--.--.----- 12

Deadwood, South Dakota, localities near
Deadwood formation, note on localities in

-- 88a, 164, 165, 355f
144

Deadwood formation (Middle Cambrian), localities in... 164, 302e, 355b
302p, 302u
614

Deadwood formation (Upper Cambrian), localities in.......
Demo ity COTOM NS coceasccoseeedoe doseaecueuscssesecouesceso
classification of. --

compared withyDisciopsis=- epee eeee eee eee sees 614
ODOUUS he Ree Peron Soe ti aet ote eee eI oe 614
ISCHIZMMDOT Nec ee ata tae teeeeet o eee ee 614
ISUPRONOtN eb Ure eas tele nae tee oe ee eee eee 614
Mr emaLovOluUs sey eae ee eee eee enee 313, 614

CRO BNO MO m2 semeenesososepscesesanopesensdeecosasses 317

general geographic and stratigraphic distribution of

thejspecies referred to. ---:- 2-22-22 2-4-2 eee ee -- 104

general stratigraphic distribution and number of Cam-
brian species and varieties of............-..-.-.-.-- 111

number of species of, in different types of sediment... 160
Shell substance.........--.-....-.-.- 297
stratigraphic position mentioned. -- 319
type species Dearbornia clarki............------------ 614
vascular markings discussed............-..--.-.--.--- 311

Dearbonniarclark?3descube Gree se eeee eee reeset ace ee 614
general geographic and stratigraphic distribution tabu-

lated: soeccoren sees eee eer Aenea osincee ee 104

type of Dearbornia. . 614

type specimen figured. .--..-.._..-..-. Pl. UX XXII, fig. 7

Dearborn River (North Fork), Montana, localities on 9k, 9m

Dearborn River section, Montana, localities correlated with - . 3j,

4q, 4q’, 4v, 4w, 5j, 8j, 9k
decipiens, see Acrothele and Obolus meconnelli.

Dedham quadrangle, Massachusetts, locality in.............----- 5
Deepi Creeks awryomine locality. O nee seee eee see eee eee eee eae 4j
Deep Spring Valley, California, localities in.................-- 176, 178a

definita, see Acrotreta.
Definitions’) sie ere en nets cee oe ene eet ope 292-296
Delano, see Mount Delano.

Delgadellas Aescribed s. 2 ate ore me ea eee eee eee 560
cardinal area discussed - 303
classification of... ..- . 321,323
compared with Lingula. ===) 000)
evolutionvdiscussedee reese aee eee eeeeeeeeee ee eeaeee 319
GvOlution(Ofteh a2 yea. cen= tetas ean aac ene tase eerie 317
general geographic and stratigraphic distribution of

thejspecies referneditomeene see eee nasee a seeeeeeeae 103
general stratigraphic distribution and number of Cam-
brian species and varieties of..................-.... 110
number of species of, in the different types of sedi-
[til \st Pe ean oHconnbooRes tote boRnbaBacanoad: Gouadsoue 160
type species “ Lingulepis lusitanica’’....-. 560
lusitanicadescribed=sseeree cece eeet cee ee eeeee te eeeenee 560
cardinalarealdiscussedes- se esssesce seca: oeeeeeee sees 304

general geographic and stratigraphic distribution tabu-

type specimen figured-...-...--

Delgado, J. F. Nery, acknowledgments

ibibliopraphicireferen Ces -eesee eee eee eee eee reese eee eee

genus named for 2

ispeciesmmamedMon=sscaicceseaes hee cece eoac ce neces eeiaeee
delgadoi, see Lingulella.

Deltidium, compared with pseudodeltidium ..... .............-.-- 306
defined 23-545 FAs sce e oe sates eae ie Mesto cena cseciestelee 293
developmentiofsss-c ace ues stateless er oe eee eee 306
GlixabeeaeloccqancouoagadooeSadaccoauceacoutBuds . 805-306
holoperipheral growth of.........-.---.------ 306

Delthynium)idefinedeeesseeessee see eee =e 293
GIscuUsseG foe esac eects ne Serie detea eee ac icienisee: 305-306

Denmark, Cambrian species of, listed...............-..-.---..-- 120-121
generalized section of Cambrian and Ordovician in, listing

included and correlated species and localities..........- 144-146
Jocalitieshins2 s<4 = S55 28s oNaaeisecesss seecstee 16h-1, 334, 334a-h
See also Bornholm.
Dennis, see Mount Dennis.
Mentaliplates; defined. s/t cs \s.c2eee se se noses si eee 293

discussed,

relation of, to spondylium discussed by Ulr’ch... aa 308
Dentalisockets) defined tenses -ses= ses ee eee ee aneee tea a Pee aeeeee ee 293
depressa, see Acrotreta.
descendens, see Acrotreta ophirensis.

Deseret road, House Range, Utah, locality on...................- llo
desiderata, see Elkania and Lingulelia.
desmopleura, see Eoorthis.
desmopleura nympha, see Eoorthis.
Deudraeth) Wales; locality ats 52-9) 02- snes ee es seeae see sees 366p
Devils Lake, Wisconsin, localities near 81, 81b, 81o, 328
Deweys Bridge, New York, localities near_..........-...-..-- 109, 367k
diablo, see Eoorthis.
dice, see Billingsella.
Dicellocephalus, see Dikellocephalus.
Dicellomus described ae: eaten ase oe ee eee oe eae ce et ae 571
articulating processes discussed............-.-...--..- 307
cardinal area discussed_.-.../.-.---...+-/-----..--.-- 304
GESSTICEIMON One jeceaccasassseccdoseeee - 321,323
Compared withvAlcrotretd es 2----- == see eee eee ee eae 312
GUTLICU me etaie hashes Hie Sats ASE ee Sa 369
Linnarssonella tennesseensis .... 670
(O}OT s S ER Sa ease Le eee ee SE ARSE noe 592
Obolus 312
Obolus chinensis 387
evolution discussed 318
evolution of Se 317
general geographic and stratigraphic distribution of
the species referred to.............--..------------- 103

826

Dicellomus—Continued.
general stratigraphic distribution and number of Cam-

brian species and varieties of-.-.-....-------------- 110
muscle scars discussed......-------------------------- 312
number of species of, in different types of sediment... 160
pedicle semitube discussed. .......--..-------------- 314
surface ornamentation discussed.....-..--.-------.--- 302
type species ‘‘Lingula polita”” 572
vascular markings discussed. 311
appalachia, described.-.-.----------- 572
compared with Dicellomus politus = — BYill
Dicellomus sp. undt...--.---------------------- 578
general geographic and stratigraphic distribution tabu-
lated) 005 se se See NC ei cee eee ee eee 103
type specimen figured - Pl. LUI, fig. 4a
manus, described ...--.-------------------- - 573
compared with Dicellomus appalachia. 572,
Dicellomus pectenoides..--------- 575
Dicellomus politus 577
general geographic and stratigraphic distribution tabu-
late dis: a eee ae eee ie se ere eee ace te 103
stratigraphic position of type specimen diseussed . -- -- 574
type specimen figured....---.-------------- Pl. LIU, fig. 2
parvus, described. - g 574
general perenne and stratigraphic distribution tabu-
Tate dae eeen eee ea ce sneer ie eerse = eae 103
type specimen figured_....-----.--- Pl. LX XXIX, fig. 11b
pectenoides, described 578
compared with Dicellomus politus ---- 577
general geographic and stratigraphic distribution tab-
MEV 6-5 See soeeceste cise anseeSeScaas+ 252 Sons suar=s 103
type specimen (?) figured... Pl. LII, fig. 6
politus, described.-.-.-....---------------- eee ee cee ees 575
compared with Curticia elegantula.....------------- 369, 370
Dicellomus appalachia....-.-------------------- 572
Dicellomus nanus...--------------------------- 573
Dicellomus parvus...-.------------------------- 574
Dicellomus pectenoides....---------------------- 575
Dicellomus prolificus.. 578
Lingulella phaon.. . - 525
Obolella chromatica 572
Obolws sinoe....-.-------------------=---- 416
Obolus? sp. undt. f........-.----------- 493
Obolus (Fordinia) gilberti. 429
Obolus (W estonia) awrora...-..----------------- 452
GIG pRS Glob seoaeeaso-e bs ceoseee ane asas ace == soa eo 5i2
general geographic and stratigraphic distribution tabu-
Jated.-..2.-.--------.------- = +22 = 2-0-2 = 22 ner sere 103
intermediate between Obolus and Obolella.....---..--- 314
type specimen not figured.
prolificus, described. ....---------------++++---------------- 57.
general geographic and stratigraphic distribution tabu-
latedeeeeesent = 103
type specimen figure: Pl. LXXXIX, fig. 10
sp. undt., described-...-----.----------+------------------- 578
general geographic and stratigraphic distribution tabu-
Tere se ere rae ee ele er 103
type specimen figured -....----------- Pl. LI, figs. 7 and 7a

dichotoma, see Acrothele.
Dickinson County, Michigan, locality in-..........---------------
Dictyograptus slate (Upper Cambrian), in generalized section for

Russia 143

in generalized section for Sweden, Denmark, Finland, and
Norway, listing species and localities..-.......-----.----- 145
localities in......--.-.--------------------- 309b, 310t-v, 321x, 390¢
systemic reference discussed.....--------------------------- 98
Dictyograptus flabelliformis zone (Upper Cambrian), locality in.... 309h
Dictyograptus zone, mentioned... --.------.---------------------- 515

Dictyonema zone, in generalized section for Cape Breton, listing
included and correlated species and localities - - 131
MOMMA. = ssa eons assess sozsasssesseessss5 487
Diductor muscles, defined... - 293

Didymograptus slate, in generalized section for Sweden, Denmark,
Finland, and Norway --..------------------------------- 144
Dikellocephalus [Olenus] fauna, mentioned .....------------------- 378
Dinobolus, classification . ......---------------------+--++++------- 310
Hall and Clarke on development of.. 309
platform mentioned. ..--------.-.-----------+++------ 309
Dinorthis, classification of, by Ulrich.......-.-------------------- 308
compared with Hebertella 5 320

Protorthis (Loperia) dugaldensis.....------------ 0

CAMBRIAN BRACHIOPODA.

Dinorthis—Continued.
cruralium mentioned....-.-....-.-.-.-.1-.-----------
muscle scars of, discussed by Ulrich.
no Cambrian representatives...............--.-------
subquadrata, cardinal process discussed

Discina, compared with Discinolepis

mentioned.
reference to, of Orbiculoidea contraria discussed
reference to, of Orbiculoidea varians discussed
“cerfaiensis,’’ discussed
‘‘nileolus,”’ discussed. ---- ----

Discinacea, classification of.......-.----------------------------
distribution in Cambrian strata--_-.......-...--------------
genera and species referred to, described.

Discinella, association mentioned. - -

Discinide, classification of--.-.----
distribution in Cambrian strata......-..-..---.------------
genera and species referred to, described..............-.--
general stratigraphic distribution and number of Cambrian

genera and species of.........---.--------------- 112
number of Cambrian genera and species of. 112
number of genera and species in monograph. -.......-.----- 113

Discinisca, compared with Discinolepis........-..--.------------- 664
Discinolepis, described. .-.-..----.----------------- 664
cardinal area discussed se i)
classification of. -- 321,324
Cyhetinern @is-ceesconssseedseeeossssossesccenocs08e5" 317
general geographic and stratigraphic distribution of
thespeciesreferred to........-.---..---------------- . 105
general stratigraphic distribution and number of Cam-
brian species and varieties of.........-...-.----.---- 111
intermediate between A crothele and Acrotreta.......-- 314
number of species of, in different types of sediment... 160
type species Discinolepis granulata..........-.-.------ 664
grunulata, described ..---.--------.--------.-.-------------4 664
general geographic and stratigraphic distribu tion. /
TOV DIENCC ES eeceetabemesasddsntsssnobsreasseasstnass 105
typeof Discimolepis - <2 2-2 = = 22 eee ca 664
type specimen figured - . Pl. LXXXI, fig. 3
Discinopsis, described. ...-..------------------------------------- 720
CESSITCDIMNOMN Ob a. sos-soscosacqsseseseos sone aazoose 321,324
compared with Acrothyra........-..---.------------- 721
Dearbornia.-....- 614
Yorkia .....----- 611
evolution discussed.........-..---.--------.---...--- 319
COMMON Oo sacassose eesceroresseenecpetsecesees=s 317
general geographic and stratigraphic distribution of
i thespeciesreferred to-......--.--------.------------ 107
general stratigraphic distribution and number of Cam-
prian species and varieties of...........--.---------- 111
number of species of, in different types ofsediment.... 160
reference to, of Discinopsis? sulcatus discussed ---..--- 721
type species Acrotreta? gulielmt --...----------------- 720
vascular markings discussed. .......-..-------.------ 311
guliclmi, described. -..---- SLE ne cce meee 720
compared with Discinopsis? sulcata 721
general geographic and stratigraphie distribution
TOOT EN las cana saSeeeeese ese be aseesaoeaaomsacoSscec 167
type specimen figured.....--.---.----- Pl. LXXXII, fig. 5
? sulcatus, described..-....---.---------+-++-+-++-2--+-20-- 721
general geographic and stratigraphic distribution tab-
THN iGGloseenedaboddoccontssosoroo soncacmaaoacmcgsons 107
type specimen figured ......--------.- Pl. LXXXII, fig. 6
discoideus, see Obolus.
divaricator, see Lucinia.
Division Clb1 of Matthew (Middle Cambrian), in generalized sec-

tion for Cape Breton, listing included speciesand localities. 133

IG bins Sen coceaasecdnssoSaneesseesesears 2f, 2g, 301i, 3086?
Division Clb2 of Matthew (Middle Cambrian), in generalized sec-

tion for Cape Breton, listing included species and localities. 133

locality in-.......-..-.------------------2+222222-0-7 577 7* 308d
Division Clb3 of Matthew (Middle Cambrian), in generalized sec-

tion for Cape Breton, listing included speciesand localities. 132

localities nneeese see tee eer sae ee eee 2i, 2k, 301la, 308d, 308g?
Division Clb4 of Matthew (Middle Cambrian), in generalized sec-

tion for Cape Breton, listing included species andlocalities. 132

Hole sites se pose ees ons scosSeoc wonossussooacedasces 308d, 308g?
Division C1b5 of Matthew (Middle Cambrian), in generalized sec-
tion for Cape Breton, listing included speciesand localities. 182

ToCalities ae ose seee ete = ee a

301b, 301d, 301f

- INDEX.

Division Cle of Matthew (Middle Cambrian), in generalized sec-
tion for Cape Breton, listing included species and localities. 132
localitiesame= =e sn a-eeseee oe 301g, 301h, 301m, 301w, 301z, 308h

Division Cld of Matthew (Middle Cambrian), in generalized sec-

tion for Cape Breton, listing included species and localities. 132
Jocalitiestant: veoh se 2 Aas ee ee One 5 SBE 300, 3011
Division C2a of Matthew (Middle Cambrian), in generalized sec-
tion for Cape Breton, listing included and correlated species
fandilocalities!s S22 Sosa! Uae eS aN. eee toe os ne eee 132
localitysinisss. eee. see ss monet seas aeree hens ae ceee eee coe 307f

Division C2b of Matthew (Middle Cambrian), in generalized sec-
tion for Cape Breton, listing included and correlated species
and localities

localitiestimeene sees tess. cae Shee eee: cae

Division C2¢ of Matthew (Middle Cambrian), in peneeized sec-
tion for Cape Breton, listing included and correlated species

ean dilocallitieslsaeere ence eeer a. eae eee eecer wussacc2esse5 131

Hocalitieshinmes <12he eae een. = lene sees ence soe 301x, 301y, 307c?
Division C3a of Matthew (Upper Cambrian), in generalized section
for Cape Breton, listing included and correlated species

am dilocalibies f= sac gees ke on thurs sate ae eee eee 131

localities in_.........- 10r?, 301e, 301n, 301t, 308a, 308b, 308f, 325b
Division C3b of Matthew (Upper Cambrian), in generalized section
for Cape Breton, listing included and correlated species

AT AR OGALIGIOS 7 ams Se alas & cleis oe eee eee eerie eee 131

TORN RES ee cance sooaesceeses 301u, 307e, 307h, 307i, 307j, 325
Division C3ce of Matthew (Upper Cambrian), in generalized sec-
tion for Cape Breton, listing included and correlated species

andiocalitiess:mess.s2= =e sees son cer ee eee ee 131

localitiesfime: 220 22o os seacsrenence ee scence 307, 307e, 307h, 307j, 308

Division C3c2 of Matthew (Upper Cambrian), in generalized sec-

tion for Cape Breton, listing included species and localities. 181
locality in -. 307a
Division E is the Etcheminian, which also see for lists of localities.
Division Ela, in detailed section on Dugald Brook, Cape Breton.. 134
Division E1b of Matthew (Middle Cambrian), in detailed section
on Dugald Brook, Cape Breton, listing included species
fandilocalities as. ysis chee ss seaee aie acc ste eee od

localities pints sso aa rsa ie one ere serene tose 13t, 13t’, 344k
Division Ele of Matthew (Middle Cambrian), in detailed section
on Dugald Brook, Cape Breton, listing included species

fandilocalitiestyse = ssseee nese aa Sea aifamiarei2 seas 134

localities timeenosseeenen enn see esiehise se eerisacnee ecco 13t/’, 344¢
Division E1d of Matthew (Middle Cambrian), in detailed section
on Dugald Brook, Cape Breton, listing included and cor-

Telated species and localities 5 134

localities interes: pect se eae nae meee cian ee 13t’’, 344e, 344m
Division Ele of Matthew (Middle Cambrian), in detailed section
on Dugald Brook, Cape Breton, listing included species

andilocalities orp ere semsisaca seems See cin oni gee ees teens 134

IGPU Ry 1a Goes aobeas ASASE So deoseaSEuasESceTeseaeasoGOneDA 344h
Division E2a of Matthew (Middle Cambrian), in detailed section
on Dugald Brook, Cape Breton, listing included and cor-

relatedispeciesiand localities)/ masses eee eeee ea see ase 134

localities in... ..-....---- 13d, 13d’, 13d’, 13f, 13g, 13p, 13p’, 307d
Division E2b of Matthew (Middle Cambrian), in detailed section
on Dugald Brook, Cape Breton, listing included and cor-

related species and localities .......-...-...-.-.-.--.----- 134

localities:in’ e220 tesserae ete eae 10p, 10q, 13d, 13d’, 3440
Division E2¢ of Matthew (Middle Cambrian). in detailed section
on Dugald Brook, Cape Breton, listing included species

fam GploCalivles meee te ee ae eee eae eee ae es 134

HocalitiesBMy fa. ceeac sees et cm eree sooo cee eeeeeeee 13e, 344]
Division E3a of Matthew (Middle Cambrian), in detailed section
on Dugald Brook, Cape Breton, listing included species

Era! MCCAINS s oddone sasvceneugcovoseacsc oecbessosesaae5 133

localities in 131, 131’, 344i
Division E3b of Matthew (middle Cambrian), in detailed section
on Dugald Brook, Cape Breton, listing included species

and localities 133

HOE RUE A 1 one coos penonegecoocosHesssceseccoscEscoas0 5 344
Division E3c of Matthew (Middle Cambrian), in detailed seaiiion
on Dugald Brook, Cape Breton, listing included species

ATL CWLOCATILIES anes lees ce eaten eels eects eee 133

L@ CaM? Tht son sacapcmanascebacaceeaabenopasSsacapencHascbae 344a,
Division E3d of Matthew (Middle Cambrian), in detailed section
’ on Dugald Brook, Cape Breton, listing included and cor-

related species and localities. ............:.-.------------- 133

Nocalitieshindesser seems alesis eieise tasteless 13n’’, 344b, 344¢

827

Division E3e of Matthew (Middle Cambrian), in detailed section
on Dugald Brook, Cape Breton, listing included and cor-

related species) and localibieSsmeseeeeeesees a. - a6 aa 133

localities;in 22 S2 ha. saanee cues eee teen eee. = acices 13n’, 344j
Division E3f of Matthew (Middle Cambrian), in detailed section
on Dugald Brook, Cape Breton, listing included and cor-

related species and localities..........-...--------------- 133

localities in .--. 18m, 13n, 344d

Division P of Billings (Lower Ordovician), localities i Talesaisoe 314c, 314d

See also Quebec group.
Division 2 of Matthew (Upper Cambrian), locality in...........-- 2x

Division 3e (?) of Matthew (Lower Ordovician), locality in....... 301s
Djupadal, Sweden, localities in--....-...-...-.-----.-------- 320a, 3200
Dlouh& Hora, Bohemia, locality on - -- 345
Dobbs Linn, Scotland, locality at..-......-...-..-.----2----.---- 316
Dodson Ford, Tennessee, localities near 103a, 103b

dolatus, see Obolus.
Dolgelly, North Wales, localities near....--.. 318, 318c, 318f, 366g, 366h
Dolgelly group, in generalized section for England, Scotland, and

Wales, listing species and localities................-.-.---
Dome Canyon, House Range, Utah, localities in

llw,
30c, 30d, 30e, 31s, 31v
Dome Canyon limestone, in detailed section in House Range,

Utah, listing included and correlated species and localities. 157
Dome Lake, Bighorn Mountains, Wyoming, locality near.......- 168
Domglint, Esthonia, Russia, locality at.....-....-.-.-1..-------- 396d
doris, see Eoorthis.
Dorsaliwalve!/defined este hesee joe eseeeeae dacseae Sa neeeee sees 293,
reasons for preservation of, in Trematobolus....-...-....- 617
Down (County), Ireland, locality in..-........-...-.-...---.----- 317
Dresbach, Minnesota, localities at.................-.-..--------- 84, 84f

Drinkwater mine, Silver Peak quadrangle, Nevada, locality near... lv

Druidhill Burn, Scotland, locality at..............---..---------- 316b
Dry Creek, Montana, localities on... - 150a, 152a, 152b, 153, 153a, 154
Drytony england locality atecs=see== ee eases ee eee eee ee eneee 304i
dubia, see Lingulella and Siphonotreta.

Dublin (County); Ireland, locality im--.--2-.----22-2_-----2-s---- 317a

Dugald Brook, Cape Breton, detailed section of Middle Cambrian
on, listing included and correlated species and localities. 133-134
localitdiesion= ssccet-tatieieGe cose oes ss ace caer aetee eee 10p, 10q,
13d, 13d’, 13d’’, 13e-g, 18k, 131, 131’, 13n, 18n’, 18n’’, 18p, 13p’,
13t, 13t’, 13t/’, 344, 344a, 344b, 344d, 344f-i, 344k-m, 3440, 372f
dugaldensis, see Protorthis (Loperia).
Dugway Range) Utah slocalityim= eee eas. =e ae eee ce 32t
Dumfriesshire, Scotland, localities in.............-....---- 316, 316b
Dunderberg mine, Eureka district, Nevada, locality near........- 66
Dunderberg shale (Upper Cambrian), detailed section, listing

included and correlated species and localities.........---- 139
Localities ime yh soe ths 5 ey seen ea ee elo asa 61, 62, 66
WASTING 6 Soagao7sseoSsossose 688, 689

Dunn County, Wisconsin, localities in. . 79a, 80, 82a, 100, 184, 134a
Dunns shore, New Brunswick, locality at........-.-.-.-.-------- 301x
Dutchess County, New York, Lingulella (Lingulepis) acuminata

in, discussed 548

WoeMAHES thee. Seaacosecostee ses 32, 108, 367d, 367e, 367j
Dwight, W. B., bibliographic references............---.---------- 16
Bagle Mills, New York, locality near__...........-.....--.-..---- 338y
Eakles Mills, Maryland, localities at.......-.....-..------------- 16f, 47£

East Bay, Cape Breton, localities on.. 10r, 13i, 13q, 307j, 325, 325b, 372d

East Braintree, Massachusetts, locality at...........-.-.-.-.---.. 326b
East Canyon, Oquirrh Range, Utah, locality in-_-..-....-....-.- 329¢
East Fork, see Paradise Dry Canyon.

East Gallatin River, Montana, localities on or near_............-. 4g,

4h, 155, 155a, 156a, 156b, 157, 158, 158a

Easton Station, New York, localities near.................... 39a, 3381
East Point, Nahant, Massachusetts, locality at...............---- 326¢
IOP Gih PTS) MoM ES Moe 5 oo ap scecenecoscoessoens 386, 386a-c, 386i-k

localities in, correlated with those of Russ’a......-.-------- 143

Eau Claire, Wisconsin, localities near.................-.--- 78a, 98, 98x
Eau Claire County, Wisconsin, localities in 78a, 98, 98x
Echinospherites limestone—C1 (Ordovician), in generalized sec-
tion for Russia, listing species and localities. ............. 143
localities sinensis cock oS e eter eee a een ae 336, 336v, 386i-1
“Bdgewise beds’? (Upper Cambrian), in generalized section for

Missouri, listing species and localities.............-.--.--- 137
localities (Seespsnlap) eee sere eee eee eee 11k, 369a
referred to the Upper Cambrian. dane. dleye

Edson, George, species named for. -.-...5-----.--:--------------- 328

edsoni, see Rustella.

,

828 CAMBRIAN BRACHIOPODA.

Edwardstown, Quebec, locality in-.-.-.--....------------------- 319u
Bgan Canyon, Bgan Range, Nevada, locality in..........-------- 8f
Egan Range, Nevada, locality in........-...-...----------------- 8f
Egeberg, Norway, locality at.......-....---.--+------------------ 323V
Eggegrund Island, Sweden, locality on..--..---.----------------- 311
stratigraphic position of bowlders found on, discussed -.._- 684
eggegrundensis, see A crotreta.
Hichwald, C. E. von, bibliographic references---..-.-.----------- 16
Species ame dO see eee en seen eee eee eee ee eee eee 390
eichwaldi, see Obolus.
Ekerum, Oeland Island, Sweden, localities near.-.--..---.--- 310e, 310£
Elbe River, Germany, locality mear--.--..--..--.----.----------- 38be
Eldon limestone (Middle Cambrian), detailed section, listing in-
cluded and correlated species and localities ......-..--- 126-127
Tocalitieshims 2° 1 aaa. se nee ee ete tert ee eee ees 35g, 570
Eldorado limestone (Middle Cambrian), detailed section, listing
included and correlated species and localities......-.--.-. 140
IGTEANNES TN So decerc coosdsescocesascssecissrossesb200 54, 55, 55b, 57
elegans, see Obolus. ;
elegantula, see Curticia and Eostrophomena.
Joint, CSO M YN. oem secede sesccen ese eocegesoosaesseetaSa09 561
cardinal area discussed........----------------------- 304

Classi cation Ofsee a= s eee eee ee eee eee
compared with Monobolina
Obolus and Obolus ( Fordinia)......------------- 428
SUMED, nocabe ve sohaoacactorcsscesceesaseuS 585
development of area in...
evolution discussed. -.--
evolution of
general geographic and stratigraphic distribution of
the species referred to........-.-------------------- 103

Hall and Clarke on development of... -.-.-.----- 309
muscle scars discussed -.- 312
number of Ordovician species and varieties of-..-.--- 113
number of species of, in different types of sediment.. 160
mig tLe CSCTHDE Cer eeee eee ae ne eee eee 562
compared with Elkania desiderata 563

general geographic and stratigraphic distribution tab-
Ulsied ee ase seE nese eres jo 2 o)n soci Rn maine wenn 103

platform discussed - . sen BIKA)
type specimen figured........-.--....-- Pl. LI, fig. 2a
desiderata, described........-.---------------- 562
compared with Dicellomus pectenoides 575
Elkania ambigua.-.........--.---------------.- 562
Elkania ida... .
QWs soc sotansesaae seo soncuscesseroseeeaee 562
QM aime aosceee sons abodes Sac cee amenosesoose 563
Obolus apollinis........------------ --- 062
Obolus ( Fordinia) perfectus 430
discussed 561
general geographic and stratigraphic distribution tab-
ENG a5 ote co scdn soeaeiescsceboceansocomoses aoe 103
Ein aed Gebel ~~ cee once ne sso Ic sds sedeceesaeeas 310
type specimen not figured.
idan dlescri bed sore: Sateen eee cee eer ae ene 563
general geographic and stratigraphic distribution tab-
Usted fsseen Awe sack Ree Rootes eee eres 103
platform) discussed. ~~ ~~. - 2. - === 2-2 eee 310
type specimen not figured.
Elkaniine, classification of. ......-.---------------------------- 321,323
genera and species referred to, described -.---. 561-564.
Elk Pass, Yellowstone National Park, Montana, locality in.....-- 302f
Elk Range, Colorado, locality in..........---.------------------- 360c
ella, see Obolus ( Westonia).
ella onaquiensis, see Obolus ( Westonia).
Elliptocephale asaphoides, association mentioned -...------- 473, 531, 605
Elliptocephala asaphoides fauna, mentioned ...-.--.--------------- 594
Ells, R. W., species named for....-.....--.---------------------- 496
ellsi, see Lingulella.
elongata, see Obolella crassa.
elongatus, see Obolus ( Westonia).
El Paso County, Colorado, localities in.....-.----.--------------- 186,
186a, 187, 360, 3602, 360d, 360f, 360¢
El Paso County, Texas, locality in. -....--.---.------------------- 353b
Elvins, Missouri, localities near...-.--..---.----------------- 369a, 369c
Elyins formation (Upper Cambrian), in generalized section for
Missouri, listing species and localities... ....-.--..-------- 137
localities in.....---.---- 11 1, 369, 369d

Ely, Nevada, locality near......--------------------------2-0++-- 8p

Ely Mountains, Nevada, localities in...-...-.-.-.---------------
Emigrant formation (Upper Cambrian), localities in......-....--

‘Is,

‘Tv, 7x-z, 8a, 8b’, 8r

MOWOO) Ns co dinoccosscHyseeoss peaoeooneSeaor sor se scasorsoacoS
Emigrant Pass, Nevada, localities near......-.

137

. tx-z, 8a, 8b’

Emigrant Peak, Nevada, localities near .. Tz, 7s, tv, 8r
Emigsville, Pennsylvania, localities near. .--.--- 49, 49b, 49c, 49w, 346
Emmons, E., bibliographic references. .........--.---.----------- 16
species named for.....--.----------- 685
Emmons, W. H., bibliographic reference 16
emmonsi, see A crotreta.
Endlich, F. M., species named for...-.....-.-.--.---------------- 342
endlichi, see Micromitra sculptilis.

Hagervik, Norway, locality ates. sees. -ce. eee eee eee nee 323e
England, Cambrian species of, listed 120-121
generalized section of Cambrian and Ordovician in, listing

Speciesandy localities. s-sseseee see ne = ee eee ee eer 135-136

localities ite see ase = tes eee ae
“ Foobolus,”’ characterized... --

Syalonyanl Of O G0ltiS seme eee aes eee eee eat 377
Eoorthine, classification of-.........-..------------------------ 321,326
genera and species referred to, described .............----- 772-195
surface ornamentation discussed......-...-----.------------ 303
FANGS, CETOM NOs So. sac canto esssosoos dese socastecacctosensese T72
cardinal area discussed.-..---.--.-.--.-----------.--- 305
Classification| Ofsese sess sees eee eee eee eee 321,326
compared with Billingsella.- 755
SEUICEUTEO UNG Lee ee ee ee 793, 794
OWS Wy as socosccagzs0s7 sess secs sese=ere2 765
cruralium mentioned-. - 309
evolution discussed-- - 0320)
evolution of 317
general geographic and stratigraphic distribution of
the species/referned) t0= => -— =e = eee eee eee 108, 109
general stratigraphic distribution and number of Cam-
brian species and varieties of pe ll
intermediate between Billingsella and Ordovician
Ortholdss <5. ewe, Seo eae ae ene AOR e ee 773
intermediate between Billingsella and Orthis 772
leah OVAOl. = Soe ep cosbeosnsooseescusossespeo 761
muscle scars discussed... 313
number of Ordovician species ral antes Olena 113
number of species of, in different types of sediment... 160
pseudospondylium discussed...-..----.-------------- 307
reference to, of Hoorthis atava discussed 774.
Eoorthis christianiz discussed.....--.-.--------- 775.
Eoorthis ? diablo discussed... .--.---------------- 779
Eoorthis johannensis discussed aos. (v2
Eoorthis saltensis discussed. ...-.----.-------- 788-789
Eoorthis sp. undt. a mentioned im 792
“Teptena melita”’ discussed.......-.----------- TT
“Orthis sp. Pompeckj’’ mentioned .........---- 793

type species ‘‘ Orthis remnicha”’..-.---------
Ulrich on spondylium.....-.-...-.-------
vascular markings discussed........----
INGEste CSCI Ae Geena ee eee eee eee
compared with Hoorthis sp. undt. ¢
general geographic and stratigraphic distribution tab-

Watedit itn. sase2 fe sw aee cose See eee emer 108
type specimen figured..........-....-- Pl. LXXXIX, fig. 6
Giada, GESCLIDED S22 ae eee me oa ne ie 774
general geographic and stratigraphic distribution tab-
ulated... 108
type specimen figured

Gowaricd, Aescribed..---= === ae = == ae eee eee
general geographic and stratigraphic distribution tab-

christianiz, Gescribed........---------+-------------+-----.-
compared with Hoorthis daunus...-....---------------
EBIOONENISIULLLLU Ch Paaeee eee ete ee eee

EENGONE TTS 200117 bate ee

does not include Zoorthis daunus

does not include Zoorthis tullbergi.--
general geographic and stratigraphic distribution tab-

restricted to the specimens from the Ceratopyge shale. .
type specimen not figured.

108

775

791

108
775

Eoorthis daunus, described -..- SadnoadessmpeciasoasanoaceesEe 776
eharacternizedeacs ee eee ae arceseceee te eeniee eee ser 775
compared with Hoorthis christianiz.....--.----------- 775

LHoontlvisituipengiaeen serra ee ee eee ae eee 790
PROG TELS QU LTO eee eee ee eee 791
general geographic and stratigraphic distribution tab-
U1Steds sone anc eee screen ese mae Case ee ea acGae 108
the “ Orthis christianiz”’ from the Ceratopyge limestone 775
type specimen figured................-..-- Pl. XCV, fig. 2a
desmopleura, described ....-..-------- V7
compared with Hoorthis kayseri 782
Eoorthis linnarssoni....---.-.------------- 783
Hoorthis pagoda 785
Hoonthiswichiensts) eee eee ae 790
general geographic and stratigraphic distribution tab-
WIL Ghe wes Gentes dae cucmacHospsosecr sueuceneeonerna 108
type specimen figured...............-.--. Pl. XCVI, fig. 1h
desmopleura nympha, described........--------------------- 778
general geographic and stratigraphic distribution tab-
WUE ICO Bas 4a aa pean coeEsEraSdessanadabHccdssaaaue 108
type specimen figured agi .. Pl. XCVI, fig. 2
? diablo, described. .........-.------------------ +--+ -2----- 778
general geographic and stratigraphic distribution tab-
WILWAGl Sond pods neoacheokmudonee copegcoescanissecceascs 108
type specimen figured Pl. XCIII, fig. 3
doris, described....-.....------------------2-+++----22--+--- 779
general geographic and stratigraphic distribution tab-
WIIG, oso oScenassnosedncee cobs asacoseresassccoods 108
type specimen figured . Pl. XCVII, fig. 13a
hastingsensis, described. ....-..- 779
general geographic and stratigraphic distribution tab-
KCl coo tonasecascoas coasoSneosssbogenseaccsnte5 108
type specimen figured......-....--------- Pl, XCIV, fig. 3
addingsi, described 780
compared with Eoorthis newtonensis 784
general geographic and stratigraphic distribution tab-
MEVIEG |. sos cncesasaosadoscencsoatequessonsssageScEO: 108
type specimen figured.........-...- . Pl. XCI, fig. 3
aindianola, described .........----.-------------------------- 780
compared with Hoorthis doris........-..-------------- 779
SHOOTUNISTLCOUNG See eee ee eee ieee eee 730
Eoorthis newtonensis 784
Eoorthis primordialis 785
general geographic and stratigraphic distribution tab-
DING omens cccesooroese con scosncagseoseneeosconS 108
type specimen figured ............--------- Pl. XCIV, fig. 2
johanmensis, described.....--------------------------------- 781
compared with Hoorthis hastingsensis....--....------- 779
general geographic and stratigraphic distribution tab-
WIG. oo ocenssccosetcoesccoe ssoensoadageoase cose 108
type specimen figured .-- Pl. XCVI, fig. 10
Kayseri, described... -------.-------------------.-----.---.. 782
general geographic and stratigraphic distribution tab-
WIDIRCL cos sacoosusoeanssoosnosaseseneedapcnodgseas 108
type specimen figured. Pl. XCVII, fig. 6a
Kichowensis, described....-.------ 782
general geographic and stratigraphic distribution tab-
(WUDHEC!. soo cseceenocenossesysccosszeonasoocssooesces 108
type specimen figured.............-- Pl. LXXXIX, fig. 5
linnarssoni, described 782
compared with Hoorthis kayseri- 782
general geographic and stratigraphic distribution tab-
WHO. ~~ -sesooscconcedood socsaeceassag2canocsaqos 108
type specimen figured-.-..-..-.-.....-- Pl. XCVII, fig. 5a
melita, discussed. .-.-..----- 7717
mewberryi, described. 783
compared with Hoorthis zeno.:.....--..--..----.----- 792
general geographic and stratigraphic distribution tab-
(NEEL ososccos Saititseheehass 108
type specimen figured. . text fig. 69B,783
mewtonensis, described..-...-------.---.--+.---------------- 784
general geographic and stratigraphic distribution tab-
HEVIEGl 2 ce ssdasconerscesdoncoonctercenssendsacansc 108
type specimen not figured.
‘pagoda, described...-..-----------.------------.-------=--= 784
general geographic and stratigraphic distribution tab-
WESIAE lp oengdsanceceadan se soso SH soqpscesteasesegas0r 108

type specimen figured........-..--.----- Pl. XCVII, fig. 12

INDEX.

Eoorthis papias, described ....-..---.-------+0------+----- 225002 785
general geographic and stratigraphic distribution

(ECOL obo ccmncooacenopercusceooescagsoceeuseEcd 108

type specimen figured ..........-.---------- Pl. XCI, fig. 4

primordialis, described: ---.-2---22-2-===--==--------------- 785
, general geographic and stratigraphic distribution

tabulatedeeeee testes sees tere eee eee reer en 108

“intermediate between Orthis and Spirifer”..--.------ 785

type specimen figured..........-.-------- Pl. XCVII, fig. 1

TEM Cha CeSChI DCU ete ee eee eet 786

cardinal process discussed peepee ee eects ao 306

compared with Billingsella exporrecta..--..------------ 755

Billingsella retroflera. ..-.---.------------------ 761

Hoorthis ? diablo - .-- 778

Hoorthis indianola. 780

Eoorthis newberryi....- 783

Hoorthis remnicha texrana 787
Eoorthis remnicha winfieldensis we) fess)
SHOOTS LUCIE eee eee ee oe UB)
HOOnTNSMUICHILOENS1Seeen eee eer eeee eee eee 790
DONORS COUT. so cco ccs detoncccsseceacaeco=0e 791
Finkelnburgia osceola. - 795
ONUSTORLENTICULLOTS See eee eee eee eee eet 767
general gedgraphic and stratigraphic distribution
tabullatede Stee se eee sce seat eer seme 108
type specimen not figured.
shell/sectionifietimed assess p ee = eee =e
remnicha sulcata, described
compared with Finkelnburgia osceola...-.------------ 795
general geographic and stratigraphic distribution
UOIQUIENCCS oes ceo snes ssbodaesesccoesenaccoosssisouc 108
type specimen figured.............-------- Pl. XCII, fig. la
remnicha texana, described. -..-....------------------------ 787
general geographic and stratigraphic distribution
UBIO DIE TG SR oubaocetceoascuosenonbaouadcssaposbeccod 108

type specimen figured.............-.-.----- Pl. XCII, fig. 4
remnicha winfieldensis, described. -........----------------- 788
compared with Hoorthis remnicha..........--.-------- 786
JONES GAs oage0 2202 oc went scpqse0esscce050 792
general geographic and stratigraphic distribution
(ALUN. os ose scooogmocmcaceccocsossonseseasenoS 108
type specimen figured..°.............------ Pl. XCI, fig. 2
saltensis, described 788
compared with Orusia lenticularis........--.---.----- 768
general geographic and stratigraphic distribution
{DVI 9 oe egos soso cess oeassccossasacegsses 180
type specimen figured.......-......----- Pl. XCVII, fig. 11
(ite, COIAHMICC oo ensacose porossF0s2 09s sees onesbesosseeS 789
general geographic and stratigraphic distribution
NUNC! «= se ae asec = ssoscooseosecszecssoeteceeooss 108
type specimen figured..-.....--..-.---- Pl. XCVII, fig. 15a
Ge, CEXEM YT... 52522 soos edocs sa codascc2sssesse0 789
general geographic and stratigraphic distribution
HOU WE. oo cess nbs csoosoenteoenseoropesenoszsees 108
type specimen figured... text fig. 70A,789
tullbergi, described 790
general geographic and stratigraphic distribution
THIMENC Ss ccndascomagcebesdosanooDacossdosscoenes 108
not a variation of Hoorthis christianiv........-..----- 776,790
type specimen figured.........-.-..-------- Pl. XCV, fig. 3
wichitaensis, described....-...-.---..----------------------- 790
compared with Hoorthis desmopleura.-..-..-..-----.-- T77
Eoorthis indianola......-.-------------------- 780, 781
HoorthislinmanssOnie mean ee eee 783
SHOOTENIS\POGO0 tse eeeee-ee ee e ee ar 785
Eoorthis thyone ‘ 789
Eoorthis wichitaensis leviusculus - . - 791
general geographic and stratigraphic distribution tab-
WNDIEGL. - - cc sence cseon es oossopestosssecsersoosauess 108
type specimen figured.............-------- Pl. XCIV, fig. 1
wichitaensis leviusculus, described. 791
compared with Doorthis wichitaensis.......--..------- 790
general geographic and stratigraphic distribution tab-
PRN. 2 secoscececenoeese worst eneseviesdacetozsn60s 108
type specimen figured..........----.- Pl. XCIV, figs. 1p-s
wimani, described 791
characterized. 775-776
compared with Zoorthis christiani#......--.---------- 775

830 CAMBRIAN BRACHIOPODA.

Eoorthis wimani—Continued.
general geographic and stratigraphic distribution tabu-

IGG) coe seeegewecesagcosesaab sues pocanoscnene == lds)

type specimen figured..-....----.--- Pl. XCV, fig. 4a

2eno, described.....-.--------- Rae ete eiae sae aba sa 7ASES & 792
general geographic and stratigraphic distribution tab-

WU Xe Rae ee ean toon secu sgcimensec seco 2cnesaS 108

type specimen figured - se .. text fig. 71A, 792

Sp: undt. a, described .--- 2-2-2222 2222 ee eee nme 792
general geographic and stratigraphic distribution tab-

Wlated:. a2 Sesser e Se eee ee ee een eee einer 108

type specimen not figured.

sp. undt. b, described 792
general geographic and stratigraphic distribution tab-

ulated 2c jeescne eee eee arlene ee eee eee eee 109

type specimen not figured.

Sp. undies describ ediaseee eee eeita seems ee eee 793
general geographic and stratigraphic distribution tab-

TAGE R Seka ee ee ere se ee One ee eee eee 109

type specimen figured.........--.---- Pl. LXXXIX, fig. 7

Spor Wialiis Gl, GESOM NG == omceeesraccosconesose sos sersse2S=o5 793
general geographic and stratigraphic distribution tab-

WENO cae pebsctesrodesasegsenacomboosie oetaees=eoas 109

type specimen figured. - - Pl. LXXXIX, fig. 8

Sho WweaXalir,, Gt, CSM Oe nsec eisceaos nb soe sesseosnacsacs 793
general geographic and stratigraphic distribution tab-

ilatedin: Uopeereiecs cae seer see tc oat ne seen 109
Eoorthoids (Cambrian), shell structure compared with that of

Oxdoyvicianserotremsbaseas=eseses ae see eee 300

Eophyton sandstone (Lower Cambrian), in generalized section for
Sweden, Denmark, Finland, and Norway, listing species
fan dllocalivies peeps creer ease nee eee ae see ene eee 146
localities in......-...----
Eostrophomena, described ---.-.-.-

cardina)/area discussed=-_- 3. -2---)-=--2-------------- 305
elassificationsoleesees seo esee ea eee eee eae aoe 321, 326
eyolutionidisemsse dessa mes ee ee seme e ee eerie 320
evolution of.....-.-..----- Sos eR babe boeraesnsose cee 317
general geographic and stratigraphic distribution of
the species referred to........-..------------------- 109
general stratigraphic distribution and number of Cam-
brian species and varieties of..........-...--------- 111
number of species of, in different types of sediment.. 160
typesp. ‘‘ Strophomena ( Eostrophomena) elegantula”.. 796
elegantula, described...-.:.-.-..-.----------------.---------- 796
general geographic and stratigraphic distribution tabu-
atGd Us tee: COPE annie a eaten met Weer icc tas 109
type specimen figured. . - Pl. XCV, fig. 6
“palcotti,” discussed... .---- say 0
BESTEL EO 1G Cl C0 eee 294
erecta, see Nisusia (Jameselia).
Erinnys venulosa, association mentioned.......-.---.------------ 498
eros, see Lingulella (Lingulepis).
Erras, Esthonia, Russia, localities at .-.--...-.----.------------ 337, 337d
Ersholmen Island, Sweden, locality on.....-.--..--..--.--------- 31lv
eryx, see Acrothele matthewt.
Escabrosa Ridge, near Bisbee, Arizona, locality on...........---. 358b
Escanaba River, Michigan, locality on---...-.-.----.------------ 330a
escasoni, see Obolus (Westonia).
Escasonie Indian Reservation, Cape Breton, locality near -.-..... 344e
Escasonie shore, Cape Breton, locality on. -.----.--.-.-..------.-- 325b
Esmeralda County, Nevada, localities in.........-.-....-..--.--. 11,
1m, 1p, lv, 7r, 7s, 7v, 7x-z, 8a, 8b’, 8r, 174c, 175, 184, 313i
Essex, New York, locality near--.......-.----------.-----------. 367h
Essex County, Massachusetts, localities in.--...--.-...---... 326c, 326¢
Essex County, New York, localities in... ..- 77, 136, 338r-t, 367c, 367f-h
sthonia, Russia, lacaliples |e oe eee el oe en 9d,

336b-d, 336f, 336h, 336i, 336m, 336r-t, 336v, 336z, 337, 337a-f,
337g-i, 3371, 395, 395a—v, 395x, 396, 396a—d, 396g—j, 396m-y
esthonia, see Schizambon.
Estillville quadrangle, Tennessee, locality in....----..-....-.-... 3746
Estillville pike, Tennessee, locality near
Btage C of Barrande (Middle Cambrian), in generalized section for

Bohemia, listing species and localities............-....... 124
OTM TWA 53 soacskcosesasossensszossssoeas2 345c, 345f-h, 345 1

Etage dl of Barrande (Lower Ordovician), in generalized section
for Bohemia, listing species and localities.-....-.-...---.- 124

NOGALES tie eemtesctestetes elelsteleleeieeietl= eee 303b, 303d, 303e, 303g-1

Etage d2 of Barrande (Lower Ordovician),in generalized section

i for Bohemia s-3230 522% So igse eect ee ene eee eas 124
Etage d3 of Barrande (Lower Ordovician), in generalized section

for Bohemia, listing species and localities ............-...- 124

Jocalitiestints «csi cek. on se ee eceee sean ene 303, 303a, 303p

Etage d4 of Barrande (Ordovician), in generalized section for
Bohemia, listing species and localities

s localities in 20 jo. 2 sesso eeee cece e< ee Satan ees eee eaneeee 303m-o

Etage le of Brogger (Middle Cambrian), in generalized section for
Sweden, Denmark, Finland, and Norway, listing species
an dilocalitiestes | 3352s ce\ce ow oer eee eee pce Wha ne eo 146

, localities in 2.222 te) 2 ees cies ereteseiaje Sisters ce ee cnet 324a, 324b

Etage 1d of Brégger (Middle Cambrian), in generalized section for
Sweden, Denmark, Finland, and Norway, listing species
and localities

; locality in.

Etage 2b of Brogger (Upper Cambrian), in generalized section for
Sweden, Denmark, Finland, and Norway, listing species
and) localitiesPu ste ca Os LoL soe eee eee eee 145

, localities in 323 1-1

Etage 3aa of Brégger (Upper Cambrian), in generalized section for
Sweden, Denmark, Finland, and Norway, listing species

andslocalifiests°*> yas22\ etc pete soe ee menace ee ee 145

Etage3a@ of Brogger (Upper Cambrian), in generalized section for
Sweden, Denmark, Finland, and Norway, listing species
andllocalitiesseeerssereeeeeeerseeaee Ne Su stocam eile seeateee Hee 145

locality: tnts))2 3910s eee cece ateastes see aiee ae eee ae 323W

i See also Ceratopyge slate.

Etage 3a7 of Brogger (Passage beds), in generalized section for
Sweden, Denmark, Finland, and Norway, listing species
andwlocalitiesis. ii. 2gue see eese gee ene eee een eee 144

localities in -....- BR ete ee cere Sater rss es 323d, 328e, 323¢
See also Ceratopyge limestone.
Etcheminian, detailed section of, listing included and correlated

Speciesjandilocalitiest#a soue-easetes -eeeene eee ee eee 133-134
Elb (Middle Cambrian), localities in..............- 13t, 13’, 344k
Ele (Middle Cambrian), localities in... 13t/’, 344e°
Eid (Middle Cambrian), localities in...........- 13t/’, 344e, 344m.
Ele (Middle Cambrian), locality in..........-.....-.-.-.--- 344h.
E2a (Middle Cambrian), localities in-.......-...-------...- 13d,

13d’, 13d”, 13f, 13g, 13p, 13p’, 307d

E2b (Middle Cambrian), localities in.... 10p, 10q, 13d, 13d’, 3440 .

E2e (Middle Cambrian), localities in ....-.............- 18e, 3441.
E3a (Middle Cambrian), localities in--..-..-..-...- 131, 13 1’, 3441
E8b (Middle Cambrian), locality in-...-.....-.------...--- 344
E8e (Middle Cambrian), locality in.............--.---.----- 344a,
E3d (Middle Cambrian), localities in - - --- 18n’, 344b, 344c
E3e (Middle Cambrian), localities in-_-...-...-.------- 13n’, 344j
E3f (Middle Cambrian), localities in.......-..--.. 13m, 13n, 344d
(Lower Cambrian), locality in.......- .... 314b
Etheridge, R., jr., bibliographic references... .- 5 16
Species named forsee. os. ee seen aa ee eee 346, 807
Etheridge, R.[Salter, J. W., and], bibliographic reference_........ 23
etheridgei, see Huenella and Micromitra (Paterina).
Etowah County, Alabama, localities in...............- 137, 138, 139, 361
Ettrick, Wisconsin, locality at 100a
euglyphus, see Obolus ( Westonia).
LO LODOLUS ss CHATACLELIZEG Ween eee nee eee Seen eet 377-378
compared with ‘‘ Acritis,” ““Schmidtia,”’ and “ Thysanotos”
by Milclewitz 32 ss0-seece- asec cee eres etree 434
Lingulelia and Obolus..--.-.-.-....--.---.-.-------.- 378
Obolus (Schmidtia) 442, 445.
mentioned..-.....--------- --> 542
synonym of Lingulella- - f 378
Eureka, Utah, localities near....-.- 34n, 34s
Eureka County, Nevada, localities in-.............-..------------ 221,
313c, and those in Eureka district, which see.
Eureka district, Nevada, localities in..........-.....----.-------- 52,

54, 55, 55b, 56, 57, 57b, 58, 59, 60, 61, 62, 62a, 63, 64, 65, 66,
201, 201a, 202, 203, 203a, 204, 205, 206a, 209, 211, 313h, 313j
Eureka district section, in detail, listing included and correlated
species and localities.......-....... PuSABB ASS Aa SkO ROHS 139-140
eurekensis, see Orusia.
Europe, zoologic list of Cambrian species of, giving distribution by
countries . 120-121
zoologic list of Ordovician species Of..........-.------------ 123
excelsis, see Trematobolus.
exigua, see Lingulella (Lingulepis).
eximia, see Lingula.

- INDEX.

exporrecta, see Billingsella.
exporrecta rugosicostata, see Billingsella.

Ersulans limestone (Middle Cambrian), locality in........----.-- 320d
See also Conocoryphe exsulans zone.
F1b of Owen (Upper Cambrian), localities in-.........-.---- 328h,3391
Fagelsang, see Fogelsang.
Fiahna Brook, Esthonia, Russia, locality on ........---.--------- 396c
<‘Wairview formation,’’ discussed .........------------------------ 131
Fall, Esthonia, Russia, localities near....-..-.- . 396b, 396c, 396i
Fall River, Massachusetts, locality near... Bee seer 326a
Falls Creek, Texas, localities near mouth of_.........----.----- 14e, 14q
iWalsetancaGefine dere seer ct. mee cere ce rials nteta fe srnete se tees 294
Families, general stratigraphic distribution of, and number of
Cambrian genera and species in.......-...-..------------ 112
number of genera and species of, in the monograph........- 113
number of Ordovician genera and species in 113
Fandango Spring Canyon, Dugway Range, Utah, locality in- - 32t
Fanglanchon, China, localities near.............--.----------- C72, C74

Fanton Island, Sweden, localities on.........--.-----
favosa, see Obolella (Glyptias).

321, 321a-d, 3210

Feistmantel, K., species named for........--..-.----------------- 392
feistmanteli, see Obolus.
Felbabka, Bohemia, locality at......../.-..---------------------- 345b

Jerruginea, see Lingulella.

Jestinata, see Nisusia.

festinata transversa, see Nisusia.

Ffestiniog, North Wales, localities near....--. 305f, 366a, 366f, 366j, 366s

Field, British Columbia, localities near.......-....-.------------- 14s,
35f, 35k, 57e, 57f, 57j, 57m, 57n, 57r, 58j-1, 58p, 58r, 58s

See also Mount Field.
Fillmore, Utah, locality near......-. Tae Re Ne ated ee ele SINS 33n
Finkelnburg, W. A., acknowledgments...............------------ 12

FOUN MRTG We 3c co scan sc see sopoesasons soos sesncaocasace 794
species named after-... 795
finkelnburgi, see Finkelnburgia.
Finkelnburgia, described----------.---.--------- === 793
@ardinal/area Giscussed!s =< 0 so- == sen ee ele 305
GUESS TION Oh os osccsosecsedooceeorsoseusoboseses 321, 326
evolution discussed ........-..--.---- - 3820
Ovolition! ofiseas eresee se aceee eee PeeeO Li
general geographic and stratigraphic distribution of the
species referred to...........-------------- woes Ske 109

general stratigraphic distribution and number of
Cambrian species and varieties of.........-----.---- 111
muscle scars discussed.........-.--------------------- 313
number of species of, in different types ofsediment... 160
pseudospondylium discussed......--....-.-.---.----- 307
type species “ Orthis (Finkelnburgia) finkelnburgi”’.... 794
(Wilmichvonts pom chy lites eet eee eels 308
vascular markings discussed. -..--...--.-.-.---.----- 312
jinkelmbumgi, described. - 22-2 ee ene anne 794
compared with Finkelnburgia osceola. - 793,794

general geographic and stratigraphic distributiontabu-
IBID oceae ss cebeacecos=sucsossorocsgsacd Goo sseSsa5 109
type specimen figured. ..........-..-------- Pl. XCIUII, fig. 2
(OSCEOLD CLES CTI Osea ee eee eee eee 795
compared with Doorthis remmicha..........----.------ 794
Eoorthis remnicha sulcata......-.-..------------ 787
Finkelnburgia finkelnburgi. - - 793, 794

general geographic and stratigraphic distribution tabu-
- oe 109
type specimen figured Pl. XCIII, fig. 1d
oscecla corrugata, described....-.--.---- 795
compared with Finkelnburgia osceola . 795°

general geographic andstratigraphic distribution tabu-
IGNIGl. = 2s soaoosdenuseesdonsoscouossasasoscabaoamenS 109

type specimen not figured.
Finland, Cambrian species of, listed...............------..-.--- 120-121
generalized section of Cambrian and Ordovician in, listing
included and correlated species and localities..........- 144-146

localitiesnimies ce ceeme csc e acer eae cee een eas 311d-f, 31lq-t, 3llw-y

stratigraphic position of bowldersin Balticregiondiscussed 454
finlandensis, see Obolus ( Westonia).
First Creek, Tennessee, locality near...-.------------------------ lla
First Creek Gap, Tennessee, locality in........-...--.------------ l4a
Fish Lake Valley, Nevada, locality near-.....-.-------.-----.--- 175

Fish Spring Range, Utah, localities in. 15d, 15p, 15x, 33d, 34g, 34i, 329d
Fish Springs, Utah, localities near........-..------------ 33d, 34g, 329d

Flagabro, Sweden, locality at.........---.----------------------- 309b
Flathead formation (Middle Cambrian), locality in...-....-...-.- 156a
Flathead River (South Fork), Montana, locality near....-...---- 4y
Flathead sandstone, note on stratigraphic position and correlation
(0) ee Alene ae oa Or See man ndct ac AoQUE Mao 137
Flathead shales (Middle Cambrian), localities in....---..---- 4¢, 4h, 4p
note on stratigraphic position and correlation of. - 137
Flat River, Missouri, localities at.........-.------------ 11m, 369
Fletcher, Virginia, locality near.........-.-..----.--------------- 331
Wlexure line; defined. --..-.--+-------+-------------------------=- 294
Flinders Range, South Australia, localities in-........---------- 315b-d

Floyd County, Georgia, localities in. .13c, 14, 96, 96b, 138a, 140a, 140c, 362a
flumenis, see Lingulella.

Foerste, A. F. [Shaler, N. S., and], bibliographic reference. .....-. 24
Fogelsang,Sweden, localities at. 309, 309a, 309h, 310h, 310t, 320d, 321z, 390b

foram end hme days see acinar ele oe efeitos 294
Foraminal tube, defined 294
Forchhammeri zone, in generalized section for Cape Breton, listing
included and correlated species and localities.....-...---- 132
See also Paradoxides forchhammeri zone.
Ford, S. W., bibliographic references. ......---.- eho Nae teed Seer 16,17
subgenus named for..........-.---------------------------- 428

(Fordinia), see Obolus (Fordinia).

Forgey Creek, Tennessee, locality on....-...--------------------
Formations, systemic reference discussed
formosa, see Mickwitzia.

Fort Ann quadrangle, New York, localities in..--...-.-.-.-------

20,
20a, 2la, 22, 34a, 38, 38a, 367a, 3671

Fort Cassin, Vermont, locality near.--....---.--.---------------- a eed
Fort Logan quadrangle, Montana, locality in 9h
Fort Mountain sandstone, section of....--..-.-.-------- sco ail
Fort Sill, Oklahoma, localities northwest of..........-...- 9p-x, 92, 12j

note on development of Reagan sandstone near......--.-..- 142

Fossil Butte, Nevada, locality at..-..-.--.-----------
Fosters Point, Newfoundland, localities near ---
Fourmile Creek, Gallatin County, Montana, locality on
Fox Glen, Wisconsin, locality at. .-.-----------------------------
fragilis, see Obolus.

France, Cambrian species of, listed...........---------.-------- 120-121

localities in.......--.--------- 342, 342a
Franconia, Minnesota, localities at 82c, 97b, 97s
Franklin County, New York, localities in....-.....-..--.----- 111, 338u
Franklin County, Pennsylvania, localities in....-.....-----.- 49d, 346b
Franklin County, Vermont, localities in-..........-.----------- 16n,

25, 25a, 26, 28, 28a, 87, 87’, 319e-g, 319j,
319k, 319m, 319q-s, 319v, 319y, 319z, 392p
franklinensis, see Lingulella.
Franklin Range, Texas, locality in ---
Frech, Fritz, bibliographic reference. .-.-..,----.---------------- 17

Fredericktown, Missouri, locality at..........-------------------- 369f

Fremont County, Wyoming, localities im-........-.-.-.----- 302e, 302p

French Creek, New York, locality at 367£

French Creek, South Dakota, locality on........----------------- 355¢

Freshwater Springs, see Resting Springs.

Fruitville, Pennsylvania, locality near. -.-.--..-.----------------- 12v

fuchsi, see Lingulella.

Fucoid beds, in generalized section for England, Scotland, and
Wales, listing species and localities. ............-.-.------ 136

Fucoid sandstone (Lower Cambrian), in generalized section for
INESHS snoeecascoteeoos ecoseb aces ccpaoedagdcachascedsce 144

in generalized section for Sweden, Denmark, Finland, and

Norway, listing species and localities. ......-...-----.-.-- 146

Tocalities ine aaa s- ene le al 309c, 309d, 396q
Gadsden, Alabama, localities at and near..............---- 137, 138, 139
Gifle, see Gefle.

Gagel, C., bibliographic reference. .--....---....-..-.--------.---- 17

Galena, South Dakota, locality at 17j
Galesville, Wisconsin, locality near.....-....--.....-----------.-- 79x
Gallatin, Montana, localities near.-.-..---.----- se SNe 302, 302j, 302k

Gallatin County, Montana, localities in.....-..........-- 4g, 4h, 4k, 4p,
147a, 148a, 149a, 150a, 151, 15a, 152, 152a, 152b, 153,
153a, 154, 155, 155a, 156a, 156b, 157, 158, 158a, 159,
160, 160a, 161, 302, 302a, 302j, 302k, 302n, 302t, 340b
Gallatin formation, note on stratigraphic position of.............. 137
Gallatin formation (Middle Cambrian), localities in 4, 4u
Gallatin formation (Upper Cambrian), localities in... 4r, 148a, 160, 302f
Gallatin quadrangle, Wyoming, localities in... ..- 302b, 302h
Gallatin Range, Wyoming, locality in...........-...--..-------- 3021

832 CAMBRIAN BRACHIOPODA. *

Gallatin Valley, Montana, localities in -..........-...-...--.-.-.. 156b,
160a, 161, 302a, 302c, 302g, 302n,
See also Hast and West Gallatin rivers.

Gamage, Miss A. O., species named for.............-...-.----.-.. 645
gamagei, see Acrothele.

Gap Creek, Tennessee, locality mear.-.-..-2. 22.25.22 22222-22- ee 18
Garfield County, Colorado, localities in-......-..1.--.... 3g, 360h, 360i
Garfield Peak, Wyoming, locality near_..........-...-...--...--. 3020
Garth North) Wales localityiateae sesseesseeeeese ae aeeee ee eeeee 366q,
Gastrikland, Sweden, locality in......................-....-..-.- 321n
Gefle, Sweden, localities near 311, 311b, 311c, 311g-0, 321e-m
Gefleborg, Sweden, localities in. .-....._. 311, 311b, 311c, 311g-o, 321e-m

gemma, see Acrotreta and Bicia.
gemmula, see Acrotreta.
Genera, alphabetic list of those in monograph, giving number of
species of each occurring in the different types ofsediment. 160
general geographic and stratigraphic distribution and num-
Deriole aoc ee eRe Se oe Sse Se 98-109

habitat of, discussed and tabulated. 160
number of Ordovician 113
species referred to listed, giving general geographic and
stratigraphic distribution and number of.............-.- 98-109
stratigraphic distribution and number of Cambrian...._. 110-113
zoologic list of Cambrian, giving stratigraphic distribution
and numbers of species 110-111

zoologic list of Ordovician, giving numbers of species. .....-. 113
Geneva (Copenhagen), Utah, localities near.. 3ly, 32c, 32n, 32y, 33t, 34m

Genitalia, shown in figure 374
Genital markings, defined 294
“Genre” nebulosa, discussed....-...-..--.---.----------.--- - 722
Geographic distribution tables..................-..-......- 114-123
Geographic and stratigraphic distribution tabulated 98-109

Geological Survey of Canada, acknowledgments..................
Geologic data '
George River station, Cape Breton, locality near
Georgia, Cambrian species of, listed ......................--..--
generalized section of Cambrian in, listing included and cor-
related species and localities..............-..........-..-- 147
localities in.... 13¢, 14, 59m, 96, 96b, 96x, 138a, 140a, 140c, 362, 362a
Georgia, Vermont, localities near...-.... 25, 28a, 319g, 319j, 319k, 319m
Germany, Hoorthis daunus in drift blocksin.....................- 776
localities ints seMAeyone ca one senses 303c, 303f, 386, 386a-1
See Bavaria, East Prussia, West Prussia, Mecklenburg-
Schwerin, and Posen.

Gerontic defined eens. erate eens nate ae oe re pm ee eck oeees tee 294
Gibraltar Bluff, Lodi, Wisconsin, locality at... 86
Gilbert, G. K., species named for................-..--.----------- 429
gilberti, see Obolus ( Fordinia).
Gillis Brook, Cape Breton, localities on........- 131, 13m, 13q, 13r, 307e
Gillis Hill, Cape Breton, locality mear_..............-............ 3n
Girty, George H., acknowledgments.....-.....-..-.....-.-.--.--- 13
Species mamedifor sos as =o weet cae aoe see eee ee 667
girtyi, see Linnarssonella.
Girvan District, Scotland, locality in........................----. 316a
Guslof, Sweden localitviateereesees =e este eee eee eee ee eee eeeee eee 320)
Givens Ford, Cowan Creek, Alabama, locality near ............. 940
Givens Mill, Cowan Creek, Alabama, localities at -. --. 94x, 94xx
Gjogrefos, Norway, locality ate: -°<2-2-2--2--22- cee eee eee 323s
Glauconite limestone (Passage beds), in generalized section for
Russia, listing species and localities...................... 143
localitiesame 2232 aie d. Hane eee 336y?, 386a, 386b, 396h-o
Glauconite sandstone (Passage beds), in generalized section for
Russia, listing species and localities...................... 143
localities ines ss sesso a teat ene oe oe 396, 396a-f
Glen Eyrie, near Manitou, Colorado, locality near................ 360f
Glenwood Springs, Colorado, localities at___- .. 3g, 360h, 360i
Glommen River, Norway, locality on............-.....-.-...---- 3230
Glossina acer, compared with Obolus (Acritis?) rugatus............. 441
Glofer sweden oc alitys aie mer a aee see eee ea eee eee ae 320W
(Glyptias), see Obolella (Glyptias).
Gold Camp, Caballos Mountains, New Mexico, locality near...... 327
Goodhue County, Minnesota, localities in
Goodwin Canyon, Eureka district, Nevada, locality in........... 209
Goose Creek Canyon, see Big Goose Creek Canyon.
Gordon Creek, Montana, localities near.................- 4q, 4q’, 4v, 8j
Gordon Mountain, Montana, localities near.........-....--.- 4q, 4q’, 8)
Gorham, Frederic P., bibliographic reference ...-.......-......-.- 17

Grabau, A. W., bibliographic reference..................----.--- li
Grabau, A. W., and Shimer, H. W., bibliographic reference... ... 17
gracia, see Acrotreta. ;

Graham County, Arizona, localities in.....................-..-- 9o, 358
Granboda, Aland Island, Finland, locality at........ Eee Tey 31lr
Grand Canyon of the Colorado, Arizona, localities in...........-.- 17e,

73, 73a, 73b, 74, 74b, 74c, 74d, 75
grandis, see Lingulella and Lingulella lzvis.

Grand Teton quadrangle, Wyoming, localities in............- 4e, 4m-o
Granite County, Montana, localities in................. 302q, 302r, 3406
Grantsville Peak, Stansbury Range, Utah, localities near........- 328,

32g, 32j, 32k, 320, 34u, 34v
granulata, see Acrothele (Redlichella), Botsfordia, Discinolepis, and
Eutorgina.
Granville, New York, localities near.................- 34a, 38, 38a, 367a
See also Middle, North, and South Granville.
granvillensis, see Lingulella.
Gravel River, British Columbia, locality on.........-.....---.--- 306

Gray, J. E., bibliographic reference.............-.-.-------------- 17
Great Belle Island, Newfoundland, locality on... 114b
stratigraphic position of beds discussed.....-.....-..-.-..-- 482
Great Britain, see also England, Scotland, Ireland, and Wales.
Great Northern shaft, near Twobit, South Dakota, locality at.... 17k
Greene County, Tennessee, localities in...-........-..-.----.- 117, 117c
Greene County, Virginia, locality in.......-....-....-..-.-..-.--- 331
Greeneville, Tennessee, localities near.............-...------- 117, 117,
Greeneville quadrangle, Tennessee, localities in .................- 102c,
103, 103a, 103b, 104, 122a, 374b
Green Lake County, Wisconsin, locality in.......-....-.....----- 328d.
“Green sand”’ (Ordovician), locality in 3371
Green’s ranch, White Pine County, Nevada, locality near........ 313e
Greenwich, New York, localities at and near..................--- 33,

33b, 35, 35a, 36b, 39a, 338f-h, 3381, 338p, 338z
See also North Greenwich.
gregwa, see Lingulella (Lingulepis).
gregwa robusta, see Lingulella (Lingulepis).

Gregwa Brook, Cape Breton, localities on..........-.-.-.-.-. 10p’, 344c

Gronhogen, Oeland Island, Sweden, locality at...........-....-... 310w

Gronwall, Karl A., acknowledgments 12
bibliographie reference: =~ 4--- =e esse aes aeee nese 17

Groome district, Nevada, locality in...............-.-.....-..-.-- 313g

groomi, see Obolelia.

Gross Lohovic, Bohemia, locality at.............-.....----------- 345j

Gruguetta, Sardinia, locality at
Gudhem, Sweden, localities at.............-......--..-2

gulielmi, see Discinopsis.

Gurich, G:, bibliographicireferences--=----2.-22--.0--2--2-------- 17

Gutturu Sartu, Sardinia, locality in the valley of............-.... 354a
Gwerny-y-Barcud, North Wales, locality at....-.........-..--.-- 318u
Gwynfynydd, North Wales, localities at..................-- 318c, 318f
Habitat, table showing number of species of each genus occurring

in the different types of sediment...........-.-..-------------- 160
Hackas, Sweden, localityjim .------- 2... 2-2-2228 t eee ee 320t
Hague, Arnold, bibliographic references.........-....------------ 17
Halfmoon mine, near Pioche, Nevada, localities at...........- 7k, 333b
Hall, J., bibliographic references........-.--.------- ile eae 17
Hall, J., and Clarke, J. M., bibliographic references.............-- 18
Hall, J., and Whitfield, R. P., bibliographic reference............ 18
Hamburg limestone, detailed section, listing included and corre-

lated species ‘and localities: ~~~ 22-22 = soe eee 139 ©

Hamburg mine, Eureka district, Nevada, locality near........... 61
Hamburg Ridge, Eureka district, Nevada, localities on or near... 201,

20la, 208a, 204, 313h
Hamburg shale=Dunderberg shale.
Hamilton, Montana, locality near...............-.---------------
Hammond, New York, locality at..............-..--.------------
Hancock, Albany, bibliographic reference... :
‘terminology of =<.-ee 2 2s - shee ncn teens Mem tees Seine eee
Hancock County, Tennessee, locality in..........-.......-..-..--
Hanford Brook, New Brunswick, localities on.-..- 2f-i,
2k-m, 3a, 301, 30la, 301b, 301d, 301h, 301i, 301v, 308

Hardingville, New Brunswick, locality at 301s
Hardyston quartzite (Upper Cambrian), locality in .............. llc
Hare Bay, Newfoundland, locality on................------------ 314g

Hiarjedalen, see Herjeddalen.
harlanensis, see Wimanella.
Harlan, Knob, Tennessee, localities near... .-. 9, 121, 121a, 123, 124, 124a

. INDEX.

Harlech grits (Middle Cambrian), in generalized section for Eng-

land, Scotland, and Wales, listing species and localities... 136
Hocallities eee ee yee = ee 318n, 3180, 366b
Harlech group (Middle Cambrian), locality in...................- 318q
Harleys wnplands locality near ---- 262s eseeesee eben eee 304i
Harpers Ferry, West Virginia, locality near. - 47c
Hartt, C. F., bibliographic references 18
Hastings cove, near St. John, New Brunswick, localities at....... 2s, 2t
hastingsensis, see Eoorthis.
Hawkins County, Tennessee, localities in........................ 9, 9a,

12q, 101, 101a, 101b, 102, 102c, 103, 103a, 103b, 104,
119, 121, 121a, 122, 122a, 123, 124, 124a, 374b, 374d

Hayden, F. V., bibliographic reference.....................------ 18
SPECIES AMO GH Om teeys erica ta Wee ote ee 338

Hayden, F. V. [Meek, F. B., and], bibliographic references.._...- 21

haydeni, see Micromitra.

Hayes, C. W., bibliographic references 18
SPECles mame donee ses sees Soe eee ee ee 505

hayesi, see Lingulelia.

Hayward Creek, Massachusetts, locality on 5

Heart-shaped cavity, defined........................ 294

Heart-shaped pit, shown in figure 374

Hebert, M., species named for 506

Hebertella, classification of, by Ulrich. 308
compared with Dinorthis........ 320
Caeia Miva TNS aN so eke oe ds sso oserensnmeseccccas 309

heberti, see Lingulella.

Hebron, see North Hebron.

Hector, British Columbia, localities near....................-.-.- 35c,

35g, 35h, 57c, 57g, 57k, 57s, 57y, 58z
8v, 323b, 323t, 324, 3244.
17b, 56c
577
4u, 302s, 340a.

Hedemarken, Norway, localities in

Helena, Alabama, localities near__.._....................-...-

Helena, Montana, Dicellomus politus from, discussed
Tocalities means = S-e once aces b= sees ces esos
See also Mount Helena.

helena, see Lingulella and Protorthis.

Helmersen, Grégoire de, genus named for...................-...- 368
RETCLVENSEM IC GESCHI DOU ee eee n= eee a eee ee eee 367
apical foramen in, discussed. 367, 368
candinalljanesi@isctisSedsas-seessas see eeee seen ee eae S 303
\ classification of 321, 322
CHIOUEMTO I CIRC WESC. - 6 Seen ceeeteesse sooseseneseecce 318
evolution of... .. Bee ee ae eee cesarean Sante 317
false cardinal area mentioned ....................--.. 318

general geographic and stratigraphic distribution of

fibelspeciesmelenre dito pesos ease ae ees 99
general stratigraphic distribution and number of Cam-

brian species and varieties of. 110
mUuscle|sears MOL SHOWIN Sees se ses seen ee eee ee 312
number of species of, in the different types of sedi-

WMARGRE 5 ca oboe cae acH ab eaasenb rec BeSUCesEceaeSOEonE 160
pedicle/opening mentioned) 22- = 52222-28222 2 se 318
surface ornamentation discussed ................__. 301, 302
type species discussed! ------- 1-2-2222 k 2 367, 368, 369
type species “ Siphonoireta ladogensis”’...............- 367

ba CLENWO] Ett) tes GASCUSSCU y= ajemee = sae en eee ee eee ee 368, 369

ladoyensis, described 3 368

cardinal area discussed. - - 303

compared with Mickwitzia monilifera....... 368

Siphonotreta verrucosa 367

GlIRG ESIC ot a aqua ctqsagnbEoaHoS aoa sondoneesooLES 367
general geographic and stratigraphic distribution

taoulabed sae ese mse wis sve ewe e oe See mee ake 99

ity peispecimentizeumre dase eee
hera, see Acrothele subsidua.
Héranity Hrance localities snes 2 =. 2-22 -2-2n-e-ee eee
Herefordshire, England, localities in
Herjeadalen, Sweden, locality in. .-........../-.........-.-..---- 3

Heterorthis, classification of, by Ulrich ........................... 308
no Cambrian representatives. ...........-.......- 320

Hicks, H., bibliographic references. - 18
SORES RICE OW. — 26 -oangocdcosose sense senseros 756

Hicks, H. [Salter, J. W., and], bibliographic reference...........- 23

hicksi, see Billingsella.

High Bridge, on Ausable River, New York, locality at.-......... 338s

Highgate Falls, Vermont, localities near._.............-
Highgate Springs, Vermont, localities near...-..........-
highlandensis, see Billingsella.

Highland Range, Nevada, localities in

62667°—vot 51, pt 1—12——_53

28, 87, 87’, 319q
26, 319v, 319y

Hillsdale, Montana, localities near_.........-...-..--------------- 150a,
158, 153a, 154, 155, 155a, 156a, 157, 158, 158a

Hillsdale, New York, locality near. ....-..--.-.--.----.---..--..- 3671
Himon mine, near Pioche, Nevada, locality at. 3334,
Ehinge ine | defined steerer = hee Mee eee SE 294
Hipparionyz, compared with Nisusia festinata.........-..-------- 728
Hipponicharion matthewi, stratigraphic position of bowlder con-
jiepiialates, OURS esc anacocesacsacosdsounousocsosoaaseesad 454, 684

Hisinger, W., bibliographic reference. .
Historical data........-.-.--.----

Hjulsta, Sweden, locality at
Hobbs, W. E., bibliographic reference
Hof, Bavaria, localities near_........-..--..--..-..--.--
Hoganiis, Sweden, locality at... -

Hokes Bluff road, Alabama, locality on.-................-- tans 139
Tralee, Win, NoyerMbiiny WERE. 2 oo soo senoesoosseosscossseces 331
Holl, H. B., bibliographic reference._........-.---....---.-------- 18

Holland, T. H., acknowledgments

Hollis Creek, Tennessee, locality on......-...-...-..----.--.----- 117¢
Hollybush sandstone, in generalized section for England, Scotland,
and Wales, listing species and localities...........-......- 135
Hollybush series (Upper Cambrian), locality in 304g
AOA MONA... ysoosscectscoosscoe seas sscconssess=reszocsSer 559
Holly Gap, see Mount Holly Gap.
Hollywood Point, Newfoundland, locality on..--...-....-..-...- 5t
Holm, G., bibliographic reference. ....-----...------..----------- 18
Holmia kjerulfi, association mentioned........-...-----.-------- 598, 600
Holmia kjerulfi zone (Lower Cambrian), in generalized section for
Sweden, Denmark, Finland, and Norway, listing species
ayavel NoeMMHOS -oseccos -oedstes sptossesossecosscodeseecace 146
ToreAMHMES Tis ossate cocoa scoccoussesesscosesssceesese 8v, 3200, 320x
mentioned 473
Holocephalina, association mentioned. .--..----------------------- 498
inflata, association mentioned .,-..-.-..-- qos SBE DEM DAAABEe 498
Holst, N. Olof, acknowledgments. --.-.----.-----..--......-....- 12
Holston River, Tennessee, localities near_......-...-..--.-.----- 9a, 104
Homer, Oklahoma, locality near-.......--..-.----.-.------.----- 12p
Honaker limestone (Middle Cambrian), in generalized section for
Tennessee, Georgia, and Alabama, listing species and
IG @RUMNTAS. - - scoasecsoson soe oscecooanassscoseedecasouscsoo0 147

IAN WM, sesescoscooessor
Honey Creek, Oklahoma, locality on--
Honey Creek, Texas, locality near...-....-....----------..-...---
Hoosac Mountain, Eureka district, Nevada, locality on
Horn, Oeland Island, Sweden, locality at..-...-------.......-

Hornet Spring, Spring Mountain Range, Nevada, locality at. .... tn
Hot Springs, Colorado, localities near........-.-----...--.--. 335a, 360b
House Range, Utah, localities in 8s, 3t, 3w,

3x, 3y, 4, 8g, 8i, 8k, 10y, 10z, 1ln—-q, llv-y, 14v, 15b, 15c, 30c-e,
30g, 30h, 30j-n, 30n’, 300, 30w, 30y, 30z, 31q, 31s, 31t, 31v, 105t
House Range section, Utah, in detail, listing included and corre-

lated species and localities.............-.......--.....-- 153-158
Houston County, Minnesota, locality in-..-.-...........-...-.-.- 84a,
Howchin, Walter, acknowledgments-.-.---.---..---.-.-------.-- 12

Howell formation (Middle Cambrian), in detailed section in House
Range, Utah, listing included and correlated species and

CAMHS, a ccacnsosssessseoaceesssesecceesecossosssssnes 157-158
HOMIES Ws oso .eogcosssocose se ssn ssansosooesseoessocs 31s, 31lv
Hoyts quarry, Saratoga Springs, New York, locality at..-..-..-. 16

Hradischt, Bohemia, locality at.-...-....-.--.---.---..-- . 303k
Hudson, G. H., bibliographic reference....---....-------- 5 18
FHfudson, Wisconsin, localities near..-...-...-.---- 79, 79’, 79b, 79s, 328]
Huene, F. von, bibliographic references......--.-----.----------- 18
EMITS MINT NF. -osossssotoossse22secssoresdesssestceoscs 805
| Huenella, described ‘ 5 805
CandimalllsireandiiscUsseC mere sesh eee sere e a= 305
ClasSiA Cajon) Olean eee ener eae ee eee 321, 326
compared with Clarkella..............-.-...----.-.---- 809
SHUODPHG 6 ocnqenoasdsboeusqusmouendpccosadesc 799
evolution discussed - 2 320
evolution of 317

general geographic and stratigraphic distribution of
thelspeciesineferred tos se sse see eee eee ee 109

general stratigraphic distribution and number of Cam-
brian species and varieties of.........-.-..-..------ 111
mentioned 807, 809
number of species of, in different types ofsediment... 160
‘oldestispecies® An assem ae sen serene see eer eeisebes 807
shell structure compared with that of Syntrophia...... 300

Huenella—Continued.
Spondylium) discussed) 22- = 2 2.— ee eee el= 307

typespecies “Syntrophiaterana”......-..------------ 805
(Uilrichyontspondy lm Sees ec eee eee essere eee 308
GUIONTIIS; CESCLIDG Case eee eee 805
compared with Huenella billingsi...........-.-----.-- 806
Huenella orientalis. 808
808
Huenella texana leviusculus. 808
Syntrophia campbelli........-.------------------ 802

general geographic and stratigraphic distribution tabu-

Tastee eee ue Ea Le miei yoreye ener psteget a eras 109
muscle scars discussed... 313
shell section figured.-....-.-.-.-.--.------ text fig. 13, p. 299
shell structure compared with that of Syntrophia later-

ALR R a PE Sens Se bea sooo ea cHbeohbosSaosdooceeD 300
spondylium discussed.........-.-- 313
type specimen figured -- Pl. CII, fig. 2a
vascular markings discussed..........--.----------.-- 312

(HPS, CES@AISHO os sear en soba eaese er eose sco oeaores 806
general geographic and stratigraphic distribution tabu-

Tate de reremetisee eee cigeee ns sce at eae ee seers = 109
type specimen figured -. .- Pl. CH, fig. 5a

elheridget, described 807
general geographic and stratigraphic distribution tabu-

JEVICG RE Eee Sa pemssenensupacsaeaesac= ache sseseeas 109

-- Pl. LXXOXTX, fig. 9

lesleyi, described
general geographic and stratigraphic distribution tabu-
Late diyseee e es bee teens og os oes pees eee ewaoes 109

orientalis, described 808
general geographic and stratigraphic distribution tabu-
109
Pl. CIV, fig. 3
808
806
806
807
Huenella orientalis. ose aseene 808
Syntrophia campbelli me 802
general geographic and stratigraphic distribution tabu-
IRIGGl soe ccosseo sete echo ssncosessesessesseseresdess 109
surface ornamentation discussed. _ 803
type specimen figured ...............--.---- Pl. CII, fig. 1
texranaleviusculus, described........--...------------------ 808
general geographic and stratigraphic distribution tabu-
IEWOG lb don aecbe sp ho saose coun conscescesseocsorsaasss 109
type specimen not figured. a
vermontana, described. ..-..--.-...---.--.--.---.-------.--. 809
general geographic and stratigraphic distribution tabu-
IBGE Sas ecocccceseestdessseosteeseeadssensscessssce 109
type specimen figured. -- text fig. 76, 809
Hulushan, China, localities on. ...------..--------------------- C3, C62
humillima, see Lingulella.
Hunneberg, Sweden, localities on..--.-.--.-. 320r, 321q, 321r, 390f, 390n
hunnebergensis, see Protorthis.
Hyatt, Alpheus, acknowledgments. -.-....-..-------------------- 12
Hyko, Nevada, locality near-.-....-.-...---------------.-------- 216a
Hyolithes, association mentioned...--....-.----- - 359, 539, 788
compared with Acrothyra........-..-- 716
americanus, association mentioned. - - 613
ef. communis, association mentioned 398

Hyrum, Utah, localities east of-31¢—e, 31h, 311-n, 54a-p, o4y, 55h, 55n, 185z
ida, see Elkania. F

Idaho, Cambrian species of, listed 114-119
Toye ANN HES Tht. | se soe gos eee soos seo eac assassin aosssesassssses5 4y,

5a-—c, 5h, 54s—x, 55¢, 55d, 56f, 56g, 59f, 59g, 163, 322, 322a

species and localities correlated with those of Utah..--..... 148-153

idahoensis, see A crotreta.

idahoensis alta, see Acrotreta.

idahoensis sulcata, see Acrotreta.

Iddings, J. P., species named for.--.-..----------------.--------- 780
iddingsi, see Eoorthis.

Tjora (Ischora?) River, St. Petersburg, Russia, localities on.. 336a, 336n

Tlgast, Esthonia, Russia, localities at.-.........-.------ 395b, 395i, 3950
Inarticulata, distribution in Cambrian strata. .......-...---------- 316
Tnarticulate brachiopods, defined.........-.-..------------------- 294

either corneous or chitinous..........-.-------------------- 296

inchoans, see Acrotreta.

807,

CAMBRIAN BRACHIOPODA.

India, Cambrian species of, listed... --.-.:-------------.---.--- 121-122
lOCaLIties til ih: Vey San on alae Seta tia ite vee lbr, 357, 357a-d

Indian Creek, Nevada, locality near..........-.--------.--------- 14m

imdianola, see Hoorthis.

Indian River valley, Cape Breton, Nova Scotia, localities in_.--.. 10p,

10p’, 10p’’, 10q, 13d, 13d’, 13d’’, 13e-g, 13k,
131, 131’, 13m, 13n’, 13n’’, 13p, 13p’, 13t, 13t’,
13t/’, 344, 344a-d, 344f-i, 344k-m, 3440, 372f
Seealso Dugald, Gillis, and Gregwa brooks.

Indian Spring, Nevada, locality near-...-........-.-.....---...-- 7a

Indian View; New York; locality om- 22220. 222s oe nse eee 185a

jflata, see A crotreta.

inflatus, see Obolus.

ingricus, see Obolus apollinis.

ino, see Lingulella.

insignis, see Trematobolus.

insons, see Lingulella.

insulz, see Lingulella atava.

Interior continental province, Cambrian species in, listed... -.-- 114-119
Interlocking plications, discussed...............--.-------------- os), SUB
intermedia, see Acrothele.

Intestine, shown in figure. ..-...-.--..------ : - 874

Inyo County, California, localities in
8b, 141, 14n-p, 58, 53a, 176, 176a, 178a, 312, 312a

Inyo Range, California, locality in_...........--..--.-.----------- 176a

inyoensis, see Wimanella.

tole, see Lingulelia.

Towa, Cambrian species of, listed... -----.--222.. 2222-22222 -5-- 114-119
localities in 341, 341a

note on stratigraphic position of localities In-............-.- 159

COT OTE Ce HOS TITIOTIG dees eee ne ee 344,359
notes on use as a generic name.....-.-..-..--- -- 3834
“sculptilis,” type of Micromitra 5 GBB
Iphidella, (deriva tionee ss. ne sae eee ease nea e ea eee eee 359
notes on use as a Subgeneric name. ..-...-..-..--.-----.-- 334, 359

UROL AS EY MUSES 8 <= Soc es zewo cs occ beesoosc: eossoese 336, 359

(Iphidella), see Micromitra (Iphidella).

iphis, see Obolus ( Westonia).

Treland, Cambrian species of, listed .......-....--.-..--.-.-.--- 120-121
TO GANMES We. 63 -coszsoesoss cass cos ecsscoerossoseolee 317, 317a

irene, see Lingulelia.

iris, see Lingulella.

Tron County, Missouri, localities in...............-......--..- 1ld, 369e
Iron Mountain, Michigan, locality at-..........-......----------- 330b
Truya, Argentina, locality at....-..---..------------------------- 389d

Ischora River, see Ijora River.
Tsenhof, Esthonia, Russia, localities at...........-
ismenc, see Obolus.
isse, see Lingulella.
Iswos, St. Petersburg, Russia, locality at-..-.--.....-----------.-
Italian Ranch foothills, Nevada, locality near. -..
Italics, explanation of use of, in localities

Mtballiys LOC aUibies iin eee ae ele ee alate eee ee
See also Sardinia. (
Ttfer limestone, in generalized section for Russia..........-------- 143
Ivangorod, Russia, see Narwa. ‘
Jackson Creek, Teton Mountains, Wyoming, localities on. ..-. 4e, 4m-o
Jackson Lake, Teton Mountains, Wyoming, localities near.... 4e, 4m-o
Jackson mine, Eureka district, Nevada, localities near...-...... 62a, 202
Jacksonville road, Alabama, locality on -.....-.-.--------------- 146
Jaggowal, Esthonia, Russia, locality at as 9a
Jaggowal Brook, Esthonia, Russia, locality on.......---.--------- 3960
Jamburg, St. Petersburg, Russia, locality at...........-.--------- 395z
James, J. F., bibliographic reference 18
Subgenus named fore = 22. 222 eee eee eel eee al 731

(Jamesella), see Nisusia (Jameselia).

Jimtland, see Jemtland. x

Jefferson County, Alabama, localities in......-- 560, 56q, 56u, 139a, 140
Jefferson County, New York, localities in.........----.-- 185, 185a, 338)
Jefferson County, Tennessee, locality im.-.-...-.-...-.-.--------- 119
Jefferson County, Wisconsin, localities in... 97a, 97¢, 328a

Jegelecht, Esthonia, Russia, localities near. ..-.--------.--------- 395,
395a, 395g, 395h, 395m, 395n
Jemtland, Sweden, localities in.....--...--.----------- 3201, 320t, 320w
Jeremejew, P. W., bibliographic reference.........----------.---- 18
Jerrestad, Sweden, localities at........--.------------------- 310u, 310x
Jewe limestone, in generalized section for Russia, listing species
anddlocalitiesce:-- eee see eee eee ene eee eee Cerca 143
“Jewesche Schicht”’ (Ordovician), locality in.....---..----------- 337e

Jinec, Bohemia, localities at.................-..-----.------- 345b, 3451
Joa, Esthonia, Russia, localities at._..................-- 395, 395, 395m
johannensis, see ELoorthis.

Johannian (Middle Cambrian), generalized section of, listing species

an CuloGalitlesses= see eee eos secs . Sd a ahr 131-132

Up ea hi nies See ee a ee ees Sen Boe Ie Ue Ss ..- 183i, 18r, 308¢
Johnson Creek, Bighorn Mountains, Wyoming, locality on....... 302y
Jomala, Aland Island, Finland, localities in.................- 31le, 311t
Jordan’s, Cherokee County, Alabama, localities near......- 93, 93n, 980
Juab County, Utah; localities in...-....-.....-2-.-.----.-------- 14t,
15d, 15x, 33d, 34g, 34i, 34n, 34s, 329d

Jujuy, Argentina, locality in....-...........-..... pees CSOD
Jutana, Salt Range, India, locality at -. . 3574
Kagerod, Sweden, locality near 309e
Kakkomaggi, Esthonia, Russia, locality at...................---- 396t
Kalmar quadrangle, Sweden, localities in-........ 310f, 390a, 390d, 390h
Kamenna hurka, localities and species in zone of, listed......-.-- 124
Kamenna hurka zone (Lower Cambrian), localities in... ....- 345i, 345]
Kanab Canyon, Arizona, locality in....................-...------ 75

kanabensis, see Nisusia (Jamesella).

Karasek, Bohemia, locality on brook of.
Karpinsky, A. P., bibliographic reference. :
Anuyelt, NoLway, locality at=--.s2-- spe ceneensen-eeaes-ess=eeeee
earyser ne. Species MaMed {OL -- =. 22-2 ses - nee ese eee eee sees ee

Kayser, F. H. E., bibliographic references...................-.--- 19
kayseri, see Hoorthis.

Keedysville, Maryland, localities near...........-.--.-.--.----- 47e; 47£
Keeseville, New York, localities near__..-...-.......... 338r, 338t, 367f
cerfhyeAte biblopraphicrererences= esse ss] =e eee eeese ee eee 19
Kelleys Island, Newfoundland, locality on - - 3l4a

Komp ys ispecies named fore =. eee es ee eeee eeacee eee 621
kempanum, see Trematobolus.
Kenlochewe, see Kinlochewe.

Kennebecasis Bay, New Brunswick, localities on ........ 2s—u, 2x, 308¢
Ketona, Alabama, locality at.-.--22.-.---------- 22-22-2222 - nee 56q
Keyes, ©. R., bibliographic reference...............--.-------.--- 19
Keyes Valley, Nevada, locality in ..............:-.-2------------ 221
Keyserling, A. de, genus named for..............-...-..-----.---- 628
SIRE BET IVIL CCS CLNTSE Cl aye eter ested tol ee ee 628
cardinaliarcaldiscusse Gmseeesse= sees se eee ee eeeer ees 305
classification of... - aA 321, 324
compared with Schizotreta elliptica- 628

Siphonotreta wnguiculata..........- SE P1628)

CUOMMNCN Olncsodcecocnocossacooas coquacesnasecceneees 317
general geographic and stratigraphic distribution
Ofthespecies referted stOm a= e eee nese eee ee 105
general stratigraphic distribution and number of
Cambrian species and varieties of..............-.... 11
number of species of,in different types of sediment... 160
pedicleymubey discussed s=sees=e see, eee Eee eee 315
type species “‘ Orbicula buchi”’.........-....-.-.-.--.-- 628
(tigit, CESGM NGC .< so occ sce ssoescossoe seo enScussscesseoue6 628
628

old-age characters discussed $15
type specimen not figured.
Cia” CURSES VC! oo pceas co nseetcesascHawenaosaseseeusdon 369
Khewra, see Kiura.
Khussak, Salt Range, India, locality at.......................... 1br
Khussak group (Middle Cambrian), localities in-......-.... 357, 357a-d

kichowensis, see Eoorthis.
Kichou limestone (Middle Cambrian), localities in-.

Kichou limestone (Upper Cambrian), locality in-..-..-.......... C74
Kambrel, Alabama, locality mean--2----- 22. 28s 2 ee eee 90c
tend erhook Creeks) LOcalluies Oly seen aera eee ease eee eens eae 29, 338b
Kinderhook quadrangle, New York, localities in.... 32a, 44a, 44b, 338b
King, William, bibliographic references..............-..-.--.--- 19

IGPINIAOOFENY Olin soo dececcecctos sestesosscces boos sheet soces 292
LTO, WUC. «+ 2 = 52 Soe see ssoc sec esesser sec oS cc eos se 506
Kings County, New Brunswick, localities in_........ 2y, 300, 301f, 308d

Kinlochewe Hotel, Loch Maree, Scotland, localities near .... 316c, 316d
Kinnekulle, Sweden, localities at--.--..-..------------- -. 320m, 390p
Kiokiapu, China, locality near. . - . C57

Kisinling limestone (Middle Cambrian), locality C32
Kiulung group (Middle Cambrian), localities in-................. Cl,

C2, C4-7, C9, C10, C12, C57, C62, C63
Kiulung group (Upper Cambrian), localities in...-...-.....-- C61, C64

Kiura (Khewra), Salt Range, India, localities at..J...-. 357, 357¢, 357d

\ INDEX.

835

kiurensis, see Lingulella.

Kiviks Esperéd, Sweden, localities at.........-..----------- 310y, 320k
Kjerulf, T., bibliographic references...........---.--------------- 19
Klittberget, Sweden, locality at.....- 3901
Knox County, Tennessee, localities in 10a,

10b, 12, 14a, 18, 106, 106a, 107, 107a, 107b, 1070, 107u, 118, 374

Knox dolomite (Upper Cambrian), in generalized section for Tenn-
essee, Georgia, and Alabama, listing species and localities. 147
localities in tese= = essa ae ee 12q, 93, 98a, 930, 105, 1070, 107u
Knoxville, Tennessee, localities near ...............------------- 10a,
10b, 12, 14a, 18, 106, 106a, 107, 107a, 107b, 1070, 107u, 118, 374
Koken, E. F. R., bibliographic reference.................-------- 19
Konigsberg, East Prussia, localities east and south of... 386a, 386b, 386i

Keonigshot; Bohemia, localivsater: se eee eee eee eee eee 303
Koporje, St. Petersburg, Russia, locality at................-- .--- 3360
Kopparberg, Sweden, localities in..................----- 8y, 310n, 3901
Kosh Brook, Esthonia, Russia, locality on.............-.-..---- - 396s
Krekling, Norway, localities at..............-..--- 323i, 323r, 324b, 324¢

Kristiania, see Christiania.
Kristianstad, see Christianstad.

Kruschna hora, Bohemia, locality at.........-- TE A ee 303i
Kucker limestone, in generalized section for Russia, listing species
and localities............ Se ea neta ctor ait aia eevee 143

Kunda Brook, Esthonia, Russia, localities on-............-- 396y, 396w

Rennitz7ESKO wey Russias lOCalit yg alae e anes nae eee eee 336p

Kusal, Esthonia, Russia, locality at................-....--.------ 337a

Kuthan, Wilhelm, species named for-.................-....-.---- 733

kuthani, see Nisusia (Jamesella).

Kutorga, S.S., bibliographic reference. .-..........-.-......-.---- 19
genus named for..........--- 579, 580
Species mamed fOr saa eee sete ee eee ee eee 692

kutorgai, see Acrotreta.

LOT G Ti, COTTAM «5-3 asad sqcass ssecosonccanedecooseeeeces 579

cardinal/area/Giscussed)su- see - sess) aeeeee eee eee 304
cardinal process discussed....-...-................... 306
classification of
compared with Micromitra (Paterina) labradorica...-- 333
Obolella 582
Oita aseacanecaseeee be asosauorteerads ane 582
Volborthia 366
evolution discussed 319
COON Oh soon sas cos be seboscoassedsessocecoccoddnee 317
general geographic and stratigraphic distribution of
fbelspeciesetente dite ee eee ease sss see 104
general stratigraphic distribution and number of Cam-
brian species and varieties of....................... 110
MAANOAA 5. cascscones soc cose sesessceae: 334, 357, 583
muscle scars discussed....................... SR le 313
© number of species of, in different typesofsediment .... 160
. Teference to, of Protorthis latowrensis discussed ......_. 742
shell structure. . 297,
stratigraphic position mentiened . 318
surface ornamentation discussed... 303
teethnmidiscussed a. -= sees eese ae . 582
cingulata, described.......-....- FY Meee PrN - 580
articulating processes discussed.........-- = (307
ASSOCA ON Men OMe Cee e eee see a eee eee 349
compared with Kutorgina yranulata.................. 583
Kutorging peculianis.--.- 822222222. 2 88 583
TOOT UGG No 2 cooaeec2see2-eescccose 584
Kutorgina sardiniaensis. . 584
OOTP NO) Windy. bos29052cus42secnseeeadeas 584
Micromitra (Paterina) prospectensis 353
confused with Micromitra (Paterina) phillipsi......... 352
RuUstellaedsonten nee eee een eee eee 328
general geographic and stratigraphic distribution
tabtlatede se. ce eememet ere kena. ape menace 104
Shell'sections'figured== 2225-2252. 5 ---- text figs. 3 and 8, 299
teethinidiscussed sees seen ee ee erent eee eee ane 582,
type specimen not figured.
Ghamulato Cesc De One ene ee eee eet eee eee eee 582
general geographic and stratigraphic distribution
babtilated neta ee esate menace een nee woe 104
surface ornamentation discussed...................... 302
typeispecimen) fipureds--2-o-2-- seeeeee Pl. V, figs. 5 and 5a
“labradorica swantonensis,” type of Micromitra (Paterina).. 344
(OTe) ESCM Ne oe cercna seco che s2S5n = see sees aeseeee 583
general geographic and stratigraphic distribution
Lab Wl atedny onstrate eens Sy eeerae nee cee aie ese 104
hypeispecimenfiplinedsn-esperece sees sees sees Pl. V, fig. 2

836

Kutorgina perugata, described....--.-..---..-.------------------- 583
general geographic and stratigraphic distribution
tabulated. 2.205. adeee cee seme sneer oe aoe eee 104
type specimen figured. .--..--.---------- _-* Pl. V, fig. 3c
pterineoides, discussed-.--.. -- eee (42
SQndUULCENSTS «CeSCHIN eC eee eee eae Eee eee eee .-. 584
general geographic and stratigraphic distribution
tabulated: 352 S eco sete ceces see ee eee eens 104
type|specimen fe uredas sss -eeee es seee eae Pl. V, fig. 4
Spyundt. described ss escee see see eee a eee eee 584
general geographic and stratigraphic distribution
tapulated)). hiteeentiane ie ose as sere ree eeeaeeeerer _ 104
type specimen not figured. :
? sp., stratigraphic position of bowlder containing, dis-
cussed. -- 404, 684
Kutorginacea, classification of........-...--.----------- - 321,323
distribution in Cambrian strata--.......-....-- son GG
genera and species referred to, described...........-..-.- 579-585

Kutoreimidee yclassiticationy 0 fseeee ashes sees ase e eae eee eee 321, 323
distribution in Cambrian strata...........-.----- aS
genera and species referred to, described 579-584
general stratigraphic distribution and number of Cambrian

PeNeTAr AM CeSPCCIES| Olem eames mie see ete ee area
number of Cambrian genera and species of. -..-..-...---.--
number of genera and species in monograph. -

Kwagunt Valley, Arizona, localities in..........-..-..---------

Labrador, Cambrian species of, listed.............-......---.-- 114-119
localitiestines-=A=haaqs0 eek eee ee ae eee sens 392a, 392c, 3921
note on stratigraphic position of localities in.............-.. 143

labradorica, see Micromitra (Paterina).

labradorica orientalis, see Micromitra (Paterina).

labradorica swantonensis, see Micromitra (Paterina).

labradorica utahensis, see Micromitra (Paterina).

La Crosse, Wisconsin, locality at.....-.---..-------------.-.--..-

La Crosse County, Wisconsin, locality in............-.-

Ladoga, St. Petersburg, Russia, locality near.
See also Lake Ladoga and Staroja Ladoga.

ladogensis, see Helmersenia.

Laesai, Bornholm, Denmark, localities at-.........-..-.-

lxvis, see Acrothele subsidua, Lingulella, and Protorthis.

levis grandis, see Lingulella.

lzviusculus, see Loorthis wichitaensis and Huenella texana.

Laggan, Alberta, localities near...............--- Prev eeacseues 35d, 35e

La Grange Mountain, near Red Wing, Minnesota, locality at....- 113
Lake Champlain, localities near_.......-...--.--.---.---.... 319j, 319k
See also Vermont.
Lake City, Minnesota, locality near.......-...-.....-.-...-...... 131
Lake Ladoga, St. Petersburg, Russia, localities near-. 236 1, 337k
Lake Louise, Alberta, localities near. ...........--.---.--.--... 35d, 35e
Lake Louise shale (Lower Cambrian), detailed section listing
species and localities. sgcrececcccrceecesess sees Sosen sera 130
eeMbhiny el 5 5 552cessesdeteesasaszces=se5 ieee teem eee 35d.

Lake Mjésen, Norway, localities near.
Lake Pepin, Minnesota, localities near.............. 97, 97x, S97x, 339¢
Lakeview Ranch, north of Brigham, Utah, localities near........ 32p,
32x, 33j, 34q, 54k, 54q, 54r, 55e, 105x

COB aK RMN. w CLASS Cato DN Olea eee eee 566
GUISCURECG!. 4 so occcsssecossesors cecsnee ersoecUSetess 565, 566

8y, 323t, 324.

Hall and Clarke on development of. ......-..--.---.- 309
platform mentioned. ..........-.----.---.-. 309
“Uinguloides,’’ compared with Neobolus warthi......--.---- 566, 567
f GUSCUREEGL. «ss ocreonceeesnosssocucostooessctosrécene 566, 567
Lamansky, W1., bibliographic reference...............--.--.----- 19
lamborni, see Obolus.
lamborni minimus, see Obolus.
Ip ba, GIS EES EC! - 5 sass co Soe sces soScossHSsssocseaCSersanesdio= 296
lamellosus, see Obolus (W estonia).
Lamotte, see Mine Lamotte.
Lamotte sandstone, in generalized section for Missouri. 137
Lampasas County, Texas, locality in..............- -. l4e, 14q
Lancashire, England, locality in_._........-......2-:--22-+------- 304n
Lancaster County, Pennsylvania, localities in-............--- lav, 346a
Lance Cove, Great Belle Island, Newfoundland, locality at....-. 114b

Lander, Wyoming, locality near_.........--------
Landis Valley, Pennsylvania, locality in
Landusky, Montana, locality near
Langston limestone (Middle Cambrian), apparent equivalent of, in
detailed section in House Range, Utah, listing included
SPeciesian Culocalies wees eee eeelete eee eee era

‘CAMBRIAN BRACHIOPODA.

Langston limestone—Continued.
in detailed section in Blacksmith Fork, Utah, listing in-

cluded and correlated species and localities............... 152

‘localitiessin\ 22452552 Sast Sse eee Oe ee 5b, 30e?, 54s, 322a
Manna Swedeno localtin ites see ees eee eee ene ee 320V
Lansdowne, Ontario, locality in.............----- --- 392d
L’Anse au Loup, Labrador, locality at.......-..- --. 392a
ansin slower OC allitiyan ate e eel see tele eee 341
Lansingburg, New York, localities at..........--....-----.--. 27a, 367b
Last Chance copper mine, Grand Canyon, Arizona, locality at.... 17e
Last Chance Gulch, near Helena, Montana, locality in............ 302s
lata, see Acrothele matthewi.
Lateralareas; defined)sai. 10: 2cisseebi vosemekoseoen oe cee ee 294
Tateral septa, Shown in figures *. 22252 see ee se eee 374
lateralis, see Syntrophia. ;
latourensis, see Pro‘orthis.
Lauzon of Logan (Ordovician), locality in-........-..-..-.-...-.- 220a.
MavalCanyon, -Anizona, locality ine see essa eee eee eee ee eee eee 74c

leda, see Obolus tetonensis.

Leeds, Ontario, localities in........--..-..--..-------- 392b, 392d, 392e

Leetz, Esthonia, Russia, localities near_........-..-.-.------ 396a, 396n

Leitches Creek, see Upper Leitches Creek.

Lemland, Aland Island, Finland, locality in..._..............-.. 3lir

ena) River, siberia, locality onisesss--45e see eaee eee sere eee eee 347

lens, see Lingulella and Obolus (Palzobolus) bretonensis.

lenticularis, see Orusia.

lenticularis atrypoides, see Orusia.

lenticularis lyncioides, see Orusia.

Meon; Spain localityinless-aasces see ee eee ee eee eee eee 350

leos, see Lingulella.

lepsis, see Lingulella.

Leppiko, Esthonia, Russia, localities at..........-...-.--.-- 396a, 396n.

Leptzna, reference to, of Protorthis hunnebergensis discussed. ---.- 741
decipiens, compared with Eostrophomena elegantula ..-.---- 796

“melita,” discussed 1717
Thomboidalis, compared with Keyserlingia buchi-.- 630
Leptenz, compared with Nisusia (Jamesella) pellico.........-.-. 735
Leptembolon, compared with Schmidtia ...........--...--..--.- OES 78
SOYA Tt] O16 le 437
(Leptembolon), see Lingulella (Leptembolon). 5
Leptobolus, characterized and species referred to or allied to listed. 472
compared with Lingulella.......-.-..-.--.--------- 472, 503
atoms ram entionedee- sea eee eerie eneee eee eae ee 472
<CCLIMUS ANSULL) NCDiONCG aa ee ee ee ee eee eee ese eee 472
“qtavus tritavus,’’ compared with Lingulella torrentis.....-- 535

Masa OValele len Gamooe semee onc opane scossbadconseoncassS 47

KC COLICLO; BAIN ON TONG Cage ee eee ee nee ee ta ree ete 472
<COOMACi@s COULS; ae eNhONe Cee a = eee ee eee eee 472
AuMenise? MeMtONG Wen \se ere nen see ee nee eee eee 472
“gemmulus,”’ discussed - 499

mentioned. .-..- 472
cL Grams te CISCUSSC Clean ae ae enee ee e eae ee eee 503
“insulz,” compared with Lingulella flumenis .......------ 501

“of. linguloides,’’ mentioned 472
“torrentis,” mentioned. ----
Lesley, J. P., species named for -
lesleyi, see Huenella.
Leuchtenberg, M. H. von, bibliographic reference................ 19
Levis, see Point Levis.
Levis shales (Lower Ordovician), locality in..............-.-..-.-
levisensis, see Acrothele.
Lewis and Clark County, Montana, localities in.. 4u, 9k, 9m, 302s, 340a

Liaotung, China, localities in. .--.-/.---..--.---..----....-.-- 332, 3382a
Liberty, Bear Lake County, Idaho, localities near_............... 55c,

56f, 56g, 59f, 59g, 163, 322
Libetschov, Bohemia, locality at........-.---.------.-.----.---.- 3031
Lidk6ping, Sweden, localities in........-...-.--.-.---.....- 320m, 320p

Lieben, Bohemia, locality at.-...--......- 303m
Likkat, Esthonia, Russia, locality near. 396s
Lillviken, Sweden, locality at............-...-...-... 3201
Limestone, number of genera and species identified from--....... 160
Limestone and sandstone, number of genera and species common

tov bobbi. a56 2c es tac oS eee Ce RE eee aE ee 160
Limestone and shale, number of genera and species common to

‘Dothis sco. See Ae a aoe ne ee ee CEE ee eee 160
Limestone, shale, and sandstone, number of genera and species

COMMONTLOVall Dh Tee sees ae ee eee eee eee eee 160
liméensis, see Acrotreta wplandica.
Limon Island, near Gefle, Sweden, localities on........-.--- 311m, 311n

INDEX.

Lincoln County, Nevada, localities in 7k,
Jn, 14m, 30, 31, 31a, 3lu, 216a, 313¢, 333, 333a, 333b

eindstrom, G.,.Speciesmamed for. ----ss2 ses ese eee ener 596, 757

lindstromi, see Billingsella and Obolella.

lineolata, see Lingulella.

Dingula, association mentioned..........-.........--.------------ 788
Classification 2-0 Sas. cee oko et oe ee eee eee 310

compared with Lingulella..............---- 376, 471, 472, 473
Lingulella(Leptembolon)...--..-.------------ 541,542

OBOlUS SNe Sas se ode eceees tse cee 373-376
development of platform in 309
evolution discussed................-.-.- eee S19}
SEN TONE erase sete eee 297, 386, 407, 471, 482, 508, 512, 532
shell structure of, compared with that of Obolus.-.... 296
vascular markings mentioned...........-.-..--.-.--- 311

SULCUUMIUN CLO CTL UOM CO emma nee eee =e eee 386

type of Lingulella (Lingulepis)...-..-..-.--.--------- 474

anatina, compared with Lingulella acutangula -- 474
compared with Lingulella (Leptembolon) lingulz-

543

374

“antiqua,’’ compared with Obolus belli... -. 386

“attenuata,” compared with Lingulella.....-..:..-.-------- 473

compared with Lingulella bornemanni....---------- 483, 484

Linguletla heberti............-.,-----=---------- 506

“qurora,” type of Obolus (Westonia)........-.------------- 378, 450

cha bzllingsiana. Giscusseds-—- = seas see eee eee ena 503

cincta, surface ornamentation discussed......-.-.-.--------- 301

EPIC OMTUGCUL, +4 GISCUSSCW 2-25 -o as eee oe ones aeeiee ee naeee eee 515

“cyuneata,’’ compared with Lingulella acutangula.....--..-- 476

*davisi,”’ type of Lingulella 469

««? dawsoni,’’ discussed and original description copied ... 497,498

eximia, surface ornamentation discussed ....-..-.-.-.------- 301
OATES? WOM AOC 5 35=seon sos an cose oesscosonesesecs 531
“«? favosa,”’ type of Obolella (Glyptias).........-------------- 599
KO TELSEMU NLC +s THe LONG Giese ee eases eas eee ae eee eee 332
lesueuri, compared with Delgadella lusitanica...-.-....----- 560
«2? monilifera,”’ type species of Mickwitzia .............----- 329
Se POTAOUICEN SiS ¥ie1 GISCUSSC Caren e eee eee nee eee eee a eee 515
“etalon,” generic and specific reference discussed . ..-..---- 402
SPU ONNUS uu GISCUSSCG eens eee ee eee 547,548
“ prima,” mentioned... - sess G18)
eOPUpTOaUcta, 21 CiSCUSSed -2- == ---225 4 - eee ee oo BS
roudulti, compared with Mickwitzia sp. undt .- oe) SEP)
MEMLIONEM se sass sees sms sees See Ce -- 584
«? warthi,”’ discussed and compared with Lingulella kiuren-
SER eS SSS SOROS GSE Ee SEE ES a aS eRe 511
(CD) ials Wee” ClO URS Eile oe cen eben cos ehees=ocessepe 703
Kccps sieniirad Za 221diseusseds. == 2. e422 see sees sane oe 531
Lingula flags, in generalized section for England, Scotland, and
Wales, listing species and localities..........--.-...---- 135-136
mentioned oe 5 Ohl
Lingula flags, Lower (Upper Cambrian), localities in............. 318c,
318g, 366d—-n
Lingula flags, Middle (Upper Cambrian), localities in........ 304g, 366a
Lingula flags, Upper (Upper Cambrian), localities in............. 305d,
318, 318a, 318b, 318s-v, 366s
Lingula or Lingulella sp. Linnarsson, discussed..........-..------ 499
lingulzformis, see Lingulella (Leptembolon).
Mingulasima, ClaSsificatlODs --e = =e == == 2 === =e ee eee ee 310
Hall and Clarke on development of.--.-------.-..-... 309
mentionedeesss= see essen sean 297
platform mentioned... 309
schucherti, classification of 310
intermediate between Obolus (Fordinia) and Dino-
WMS scaddaAsnenaronwaseneneaaboosdsaconobascuesssee 310
sHingulellan described ameeesere a acce serine ae cee eee eee aas rie 468
cardimalianrea discussed a sss— sees ae eee ee 304
Classification oftees.c8eesecee che cen ce eee eee 321,323
compared with “‘ Huobolus” ........-.--.------------- 378
Leptobolus.....-------- 503
Lingulella (Lingulepis)...--..----- 544, 545
Lingulella (Lingulepis) acuminata - -- 544
Obolwsiandelingula tes eee 376
Obolus (Lingulobolus)....-.-------------------- 432
ODOIUS(SCHNMAtiO) pte e eee a 442,
Geyelopmentio fare sssee ate ee eee eee 309
volition diSCUSSeGae a eaeeeeee ee eee ee eee =a are 319
CYOMNTOM Ol o- conocesososascceuancancooassSonorsocacsic 317

837

Lingulella—Continued.
general geographic and stratigraphic distribution of

thejspeciesireferneds tos sees eee ee oa 101-103
general stratigraphic distribution and number of Cam-
brian species and varieties of.:..-..-.-.-...-.-.-... 110
generic separation from Obolws discussed.....-..-.. 471-472
Hall and Clarke on development of.._.-.-.---.......- 309
Lower Cambrian species of, discussed -..........--- 472-473
mentioned..... 379,386, 388, 401, 414, 474, 484, 489, 490, 495, 500,
503, 508, 511, 527, 532, 539, 541, 547, 557, 558, 560, 590, 604
MOUUSCIE|SCATSIGISCUSSC Caen eee see eee ere a 312
number of Ordovician species and varieties of. 113
number of species of, in different types of sediment.. 160
oldest species: 3. save ess se seeclee se eee eee eee 530
Dlatfonmidisenissed asses — esse es ees eee eee eee eee 310
relative position of vascular sinus in species of........ 377
stratigraphic distribution discussed..............---- 473
subdivision of, on basis of outlines of ventral valve.... 470
surface ornamentation discussed............-........- 302
type species “‘ Lingula davisi”’ 469
umbonal muscle mentioned - . 313
vascular markings discussed.......-..-...-....,..-:.- 311
young shells more circularin outline thanadultshells.. 473
ccutanguia. describe deer ee ree ee ee eee aa eee seen ee 474
compared with Lingulella ampla........--.-.....- ~ 477, 478
UG UL ELLOL DUES Pee ee eee 484
LGUUG UIT ELLCRCLON KCL eee eae eee 485
EG UIGULELLONCLUILE OO pee eee eee eee 488
Lingulella davidsoni. - 489
yn GULELLONGTONULS Saeee eee eee eee 503
Lingulelia isse.... 510
Lingulelia lineolata. . 516
Lingwlella nathorsti.....-......--.-.----- 473

DLingulella perattenuata..........-..-----..----- 524

Lingulella radula 529
Lingulella schucherti 472
LEG MGM OU Usa ceo icase sen sas2eccortoseees 535
Lingulella (Lingulepis) acuminata - 546
Lingulella (Lingulepis) roberti...... 557
Obolusr See eee tees eee eee = 471
Obolu sta pOllinis peer eee nena eee 472
OnIS UATNONTNE Bs occc5s206ss002conanene sone= 394, 395
(QUINIHS SUT D sop sonsaeceécoeaccaascaaseaseeo 413, 414
Obolus ( Westonia) aurora............-.---.---.- 452
bolus] @MVEston7 0) yell eee eee eee 456
Obolus ( Westonia) euglyphus..-.....-.-.-.-.--- 461
Obolus ( Westonia) finlandensis..............-.- 462
464

101

grouped on the basis of the outline of the ventral valye. 470

TOUISC esCansIGISCUSSe Ceres aE eens eee eee ee eee 312
* type specimen not figured.

Platform enon ed Seeeseree esses nae eee eee sere 310
visceral area (splanchnoccele) characterized.........- 470
“? affinis,” type of Obolus (Lingulobolus)..-....--.-.----- 378,431 _
(OGMOSLOTIUN NM CLESCLI De Cees eens es ner eee eee ee 476
general geographic and stratigraphic distribution tab-
Ulatedseoc 2-2. fs sneee asco seseassecee asec eee sdodpese 101
type specimen not figured.
ampla, described.........----------- 477
compared with Lingulella oweni 523
Lingulella phaon Sea bP)
Lingulella pogonipensis = ase | YG
Lingulella (Lingulepis) starri-.-.......-.----.-- 559
(Obolusiiamborniaeee ee nee eee eee eee 394
Obolus ( Westonia) aurora.....-...-.------------ 452
(Qbolwsi QWesto77 a) (ell aseree ee 456
Obolus ( Westonia) notchensis......-.----------- 463
Obolus ( Westonia) stoneanus.....-....--------- 465
general geographic and stratigraphic distribution tab-
101

type specimen figured...........----.--- Pl. XXVIII, fig. 1
visceral area (splanchnoccele) characterized_..-.....-- 470
arguta;described maser sense ete ee ae eee eee ee
compared with Lingulella iris...
general geographic and stratigraphic distribution tabu-

838 |

Linguletla atava, described.....-..--..--------------------------- 479
; * compared with Lingulella atava insul#.............-. 480
Wining Wlella can asses eee ee 35)
COLIC eee ee eect esee eee 486
LUMCNIS Eek eee eee eee eee =o Sail
torrentis -. 535,536
confused with Lingulella (Lingulepis) gregwa...--.-- 479, 480
general geographic and stratigraphic distribution tabu-

Jatedcs iiss 4 see eeeee ene eee ECe eae eerie 101
type specimen figured. . . Pl. XXX\V, fig. 5

atava imsule, described). 2-222 22222 = on =e 480
general geographic and stratigraphic distribution tabu-

EWC te doce oaobosucesnandoneeanasachonbasapoteesoena 101
type specimen figured . Pl. XXXYV, fig. 8

auga, described.......-------------------------------------- 480
general geographic and stratigraphic distribution tabu-

Wea se sa nse chtaossosaocqucesonescoosscesssoaosose0 101
grouped on the basis of the outline of the ventral

470
470
type specimen figured......--.--.-.----- Pl. XXIV, fig. 6b
bella, described 481
compared with Lingulella arguta.--.-..--.----------- 479
Lingulella billingsiana.....-..-.---------------- 483
Dingulella kiurensis...-.-.------------------- 511-512
Lingulella lens 513
Lingulella lepis 514
general geographic and stratigraphic distribution tabu-

THI, £3 -eoseccadosoncenssesbesseseocosessccossoond 102
grouped on the basis of the outline ofthe ventral valve. 470
species confused with.......--.-.----------- 481, 482, 487,513
type specimen figured. Pl. XIX, fig. 2h

bellula, described....-..-.---------------------------------- 482
compared with Lingulella arguta.-...-....------------ 479.
Lingulella billingsiana.....-....------------- Le. » 483
Lingulella prima... 527
Obolus refulgens . - - - ‘ 410

general geographic and stratigraphic distribution tabu-

IGG Gl eae Aeschossccoseoateaooccneccsese sccm popen>obe 102
type specimen figured.........-..--------- Pl. XIX, fig. la

billingsiana, described .....---.----- 483
compared with Lingulella ampla- - -- 478
Ting wbella DEW UO) aan om 482

general geographic and stratigraphic distribution tab-

WEG st cdsoosncenencoseentdoos sbbossceaoauenuads 102
type specimen figured

bornemanni, described........-..----
general geographic and stratigraphic distribution

Papulatedaeesteeer me ean eee ee eee eer cma 102

type specimen figured............-------- Pl. XXX, fig. 18
(inte, CSO MIG le ons sgacconsascbesecesoosseeesseE sAseasenos 484
general geographic and stratigraphic distribution -

HEY OMULKE oor 5 eer nscookseecansssssusseocnesnesoss6 102
type specimen figured ...........-......-- Pl. XXIX, fig. 4

Ggaahit, Y GHOST. - ce canettchos rege sete reScacsseedsess 604

cania, described 484

compared with Lingulella atava............-.-.------ 480

Lingulella atava insule.........---------------- 480

Lingulella manticula..........-..----------..-- 518

Gingulellalora seen eee eee ee ee eee Se 522

BUTT ILLELLON LUD TS Eee ee 538

confused with Lingulella (Lingulepis) gregwa .,......- 485
general geographic and stratigraphic distribution

tabulated aeseetes eee ect ees e tse es ert ie 102
reference to Leptobolus suggested. .........-.--..----- 472
type specimen figured........- . Pl. XXXV, fig. 3

cedens, described. 485
general geographic and stratigraphic distribution

tabbullabediaemmrmemeterercnae see eisai eetaretaiste iat 102
type specimen figured..................-.-- Pl. XXX, fig. 8

clarket; described@ sat aeeicc sna oemce cece era ceecoese 485
general geographic and stratigraphic distribution

tabulated seereeser ster sincsecre corset ecine= siecle 102
type specimen figured. 3S

collicia® descnibedizys saneeemeeeeraer eee see cece cee
compared with Lingulella atava..........-.---.------ 480
Lingulella cania....----- 485
Lingulella flumenis - - - 501
Lingulella ora.....---- 522

Ti NG ULE ORD TS tee eee eee ea eee aie 538

CAMBRIAN BRACHIOPODA.

Lingulella collicta—Continued.
general geographic and stratigraphic distribution

tabulatedls co S45 Sele Sor ae Ue ete eI a ERO 102

type specimen figured. . Pl. XXXV, fig. 1

“collicia collis,” compared with Lingulella collicia........... 486

concinna,, described ements neta See eee eee eee 486

compared with Lingula...................222.1------ 319

SGURGUILELLU CLL eee eee ee 482

Binguilellalens's-oi-peasen \eoc eee eee 513

Obvoluslacadicusi=s- se ee eeee eee eee eee rere 380

confused with Lingulella bella ........-...------ 481, 482, 487
general geographic and stratigraphic distribution tab-

Mate dao.) seks eR Oe ker sok a0) ie 7 ee ae eee 102

type specimen figured... - Pl. XXXII, fig. 2d

““ ? cuneata,’’ discussed........ 503

CUmeOLa. GESCriDedaa= eee ees sao re ee -. 488

compared with Lingulella acutangula 476

general geographic and stratigraphic distribution tab-
WENGE <scooscoseassese Don achen haem aancaae Seer serie 102
type specimen figured....

damesi, described!) Ges-8-2 20222 eee Meee ee eee 489
compared with Obolus chinensis...............------- 387
(QUIS (OTOH Hossa sa eemccceseuceoenseeebcsescs0 409
general geographic and stratigraphic distribution tab-
wlated i seas tes eeeee soso eon ae aenaeeen 102
generic reference changed 489
type specimen figured............-...- Pl. XXXIX, fig. 8a
davidson? (described sees ssee eee ee cee eee eee eee eee 489
general geographic and stratigraphic distribution tab-
Mlatedsaceastiaste see mee eee ASSESS E EE SOE 102
type specimen figured..................- Pl. XXXIV, fig. 1
dauist7Gescribedsamreee seen ease ee eee eee eee eee eee 489
compared with Lingula.....--.-.--.--.---- Fe a sae 319
Lingulella bella... - 482
Lingulella cedens 485,
Dingulella hebertt -- 222-222-222. nese eee 506,
Dingulella kiurensis. ......-....--------- 512
Dingulella wirthi......--..-2----.-------- -. 541
Lingulella (Lingulepis) exigua.....--.----- 552, 553
Obolusprind leanne eee ee eee eee eee 379
Obolus (Schmidtia) celatus.........: i wees eneeee 472
Obolus (W estonia) ella......--..--..-+----+--.-- 456
general geographic and stratigraphic distribution tab-
Wlated. 5.5 ).6 5252-522 shew eee eee ee eee 102

grouped on the basis of the outline of the ventral valve. 470
type specimen not figured.
“of, davisi,’’ mentioned.........-.----- Cok Nee late hina dea 499

“ef. davisii Kayser,” discussed. . 490
delgadoi, described........----- 491
discussed. 560
general geographic and stratigraphic distribution tab-
wlated:s ses sea tenses science eee eee 102
generic reference mentioned .
type specimen figured..... 2
desiderata idescribed: 05-2 ee sees Leen oe See ae ee 492
compared with Lingulella manticula ........-...----- 517
DAV OULELLASUNULLS eee ase eee a5 G88)

Lingulella wanniecki 539
Obolus prindlet. . 409
general geographic and stratigraphic distribution tab-
dilated. 2:2 sf. St Sane sce eo Soe ena eee 102
stratigraphic distribution and possible specific differ-
encesin mentioned ae. s- sess sae eae 473
type specimen figured.........-...-.-...---- Pl. XX, fig. 4
dubia, described 494
confused with Obolus (W estonia) ella 495
general geographic and stratigraphic distribution tab-
ulated =e eee eee aeeeeee DEES TORRE AGHOASORS 102
platform) mentioned see cree eee anna eee eee
type specimen figured
ellsi, described....-.---.------.-----
general geographic and stratigraphic distribution tab-
WEWKG0 Dee tegat sn acmaseAnsecposeeoacencocsseadoeebs 102
type specimen figured.........-.----...---- Pl. XIX, fig. 3
ferruginea, described ...--.---------- 496
compared with Lingulella bellula.. 482
Lingulella buttsi.......-- : 484
Lingulella delgadoi......-.-.--.-------.-------- 491
Lingulella desiderata..........------------------ 492
BUTT OIULELLL CLES Date ee eee eee 495

——

INDEX.

Lingulella ferruginea—Continued.

compared with Lingulella cf. ferruginea--.-----:----. 500

Lingulella granvillensis........----------------- “504
Dring uleua lepiss = © 2.2 === <=) = ae «one en === 514
Lingulella linnarssoni........---.----+-+-+----- 516
Lingulella nicholsoni 522
Lingulella prima ..-.-.---------------+--+---+- 527
Lingulella primexva....------- 527
Lingulella signata 532
Obolus fragilis....-..-------- 393
Obolus prindlet 409
general geographic and stratigraphic distribution tab-

Tila bed easement eeiawe esse encieise nae nis fe aeseeeee 102
platform mentioned............-..-..-...---------.-- 310
reference to Leptobolus suggested... +......--.-------- 472
stratigraphic position in Europe and America com-

pared, with lists of associated species.......---..--. 498
type specimen figured....-......-..-.--- Pl. XEXIX, fig. 2b

cf. ferruginea, described .....-.-...--.....---.-------s------ 500
general geographic and stratigraphic distribution tab-

WIIG iostooouscoobbsamasoodeeaaosauoonstonudoosstos 102
type specimen figured. ...- .. Pl. XXX, fig. 4

ef. ferruginea Kayser, discussed... 499
Jerruginea ovalis, discussed..... 497
SFLUMVENTS 5 CESCUUDC Cees see eta ea = ee mie alate lala alee mma 500
compared with Lingulella ora........-...------------- 522
Lingulella upis 538

general geographic and stratigraphic distribution tab-

TIE ssc osuaoboacnouadoubanenenssscesdocsnonedoce 102
type specimen figured...........-..--..- Pl. XXXV, fig. 6

jranklinensis, described..........-----.--------------------- 501
general geographic and stratigraphic distribution tab-

(UU tL Os OS Aes sea secoa aoeceneoebononascestestoodss 102
type specimen figure

Juchsi, described...... ASHoud danacoacdaodacmepcccansascedersso 502
general geographic and stratigraphic distribution tab-

WIAYOE acne ooscauduodepasosecoEeboacuad nodocesdesE 102
type specimen figured.................- Pl. XXXIX, fig. 3

COG AI. CUATRO o- = non pscce se as senoseponoscqssssoonensocOS 495
grandis, described|.--.----.----------------- é 502
compared with Lingulella auga.......-..------------- 481
Lingulella billingsiana.........---.------------- 483

general geographic and stratigraphic distribution tab-

IIRL scons soconoae HadesongsanaosobaascoHnQnccencE 102
type specimen figured......-........ Pl. XXXVIII, fig. 2b

granulata (Phillips), compared with Lingulella heberti........ 506
GrUnuiLlensis GesCribedesnen sere eases sseesee eee selena 504
cardinal area discussed

compared with Lingulella delgadoi........--..-------- 491
Lingulella desiderata 492
DUNG WLLL OTUKULILENSTS = eit a eyelet ae 502
(QUDIIS Wis cecacenasacesebodecsacma=csaeads 409
Obolus (Lingulobolus) affinis......-.-.---------- 431
Obolus (Schmidtia) celatus....-.----...--------- 471

general geographic and stratigraphic distribution tab-

HIRO ss cscnocodasoconsmosaouseoanauasssosueues200 102
joleiitoynaal TealerauAOAl ec oscoqseonessccoscanes sees 310
type specimen figured..............-.-.--- Pl. XXII, fig. 1
vascular markings discussed............-.------------ 311

ef. granvillensis Matthew, discussed....-......- 499,519
hayes? (described. ---22------4-------- 505
compared with Lingulella phaon..........--.--------- 525
QMS CGO ssa necoacces26ecsetioooonaoDsnGSon05 389
Obolus ( Westonia) rogersi. 464

general geographic and stratigraphic distribution tab-

Cee Eee Re EAL aE Sapte AOBEan ona ae DacaCaceOcaeashe 102
type specimen figured............-.-.---- Pl. XXYV, fig. 1b
visceral area (splanchnoccele) characterized.........-. 470

HAVE HI, COSOMTAA = Sd aboc =toomsgozsocoscocsbacqaaneesuneds 505
general geographic and stratigraphic distribution tab-

(WIEN I0 SA phason ndorooosn Weapons nEaSBdEoHenSaasanen 102
type specimen figured. . = Pl. XeXSX XS fig: lib

helena, described .-..-------.- - 506
cardinal area discussed
general geographic and stratigraphic distribution tab- °

WENIGGl AoeoseasebsacSnauaaoe asaocsasaaebaosasenanoas 102
may equal Obolus meconnelli in part ......-.--.------- 396
type specimen figured........-....-. -...-Pl. XXIV, fig. 3a

Lingulella ? humillima, described ....-.-.------------------------ 507
general geographic and stratigraphic distribution tab-

EU dA Sessocsocosscoatoass 62cnd 236 COORDSEeREOS 102

type specimen figured. Pl. XXX, fig. 12

ino, described . ......-.------------ 2-22 0ee eee ee ener 507

compared with Obolus sinoe...--.---.---------------- 415
general geographic and stratigraphic distribution tab-

WUE Kelas is Sein hoo sso oncmobosasseesaroornesosoRcunuS 102

platform mentioned......-.-.------------------------ 310
type specimen figured

? insons, described . . . 508
general geograpl ic and stratigraphic distribution tab-
WIEN Gel SoS anos stosebeessecdacscaccncs es aos seoo5e 102
type specimen figured Pl. XXXII, fig. 2¢
iole, described 508
compared with Lingulella desiderata - - - 492
WHOS CHUM. «dco sscconcososcoesnsnpcenassercoe 389
general geographic and stratigraphic distribution tab-
WIENS sang pscooedododc canocccaoounaccsooonmooooese 102
type specimen figured......-..--..------- Pl. XXVII, fig. 5
HIG, CESARE = soem Se aceneeaoeenconmeenemasecansseeracase 508
general geographic and stratigraphic distribution tab-
WIAs a ocdsacoscadecbamosndcmsbonagdcnconuasaeeos 102
type specimen figured.........-..-------- Pl. XXVII, fig. 6
drign describedins ace saw saaee are cee sence eee et cee 509
general geographic and stratigraphic distribution tab-
WIIG! oo So csscossoncacedseeoesobos seennscssenescan 102
type specimen figured..........---------- Pl. XXVII, fig. 2
KRG, GESOMO | oo es-concasnooobSnescnassstossueenonseesces 509
compared with Lingulella pogonipensis 526
Lingulella wanniecki....-..-------------------- 538
general geographic and stratigraphic distribution tab-
in ELCs poudascodsdouecedanucosecpConabenesyouueuCEa 102
stratigraphic range discussed and compared.....----- 510
type specimen figured Pl. XXXIX, fig. 4a
kiwrensis, described ....-.......---------------------------- 511
general geographic and stratigraphic distribution tab-
BIG «6 ono nop aosnenenscooudacogonDOESopoMaESETSENS 102
type specimen figured...........--- Pl. XXX, fig. 6
levis, described .....- pile Budd ononbadeEDsoddaSDcodasbancronon 512
compared with Lingulella levis grandis . son I
Lingulella lens 513
general geographic and stratigraphic distribution tab-
WII coossesoscocecesosooasnqonescoescocomnscssess 102
type specimen figured.....-...---.-..------ Pl. XIX, fig. 4
lzvis grandis, described. .....-..-.-------------------------- 512
general geographic and stratigraphic distribution tab-
(MENG! 2 sccsascesceoseososo 102
type specimen figured . Pl. XIX, fig. 4e
lens, described... ..--------- 000-292-2220 ne nnn ene 512
compared with Lingula.........-..-------------------
Lingulella bella.....------
confused with Lingulella bella. .
GURGERSOCl 5 ooo: cossaasbessseorsoossonsseesseeescoess
general geographic and stratigraphic distribution tab-
MNCL con sconccscnonoogs 7200s snosseosecoobenasasesa 102
type specimen figured... . . Pl. XXXII, fig. 1
Zeosidescriped esse Pree errr ee eerer 513
general geographic and stratigraphic distribution tab-
EWG emdebsocdeseudsesmadguanoonboopsuepacessedse 102
type specimen figured...........-.-.-.-- Pl. XXIV, fig. 2a
visceral area (splanchnoccele) characterized.....-..... 470
lepis, described 514
compared with Lingulella ferruginea.......-..-------- 499
Lingulella linnarssoni ..-..-----------=---- . 516
Lingulella nicholsoni......------.--------------- 522
general geographic and stratigraphic distribution tab-
WEE ccc cose satsceosctec sonacceonponscenesScnaocd 202
reference to Leptobolus suggested..........-.--------- 472
type specimen not figured.
lineolata, described. -----22-:------------«--------- - 515
compared with Lingulella franklinensis Bee 502)
' Obolus ( Westonia) euglyphus....---------------- 462
general geographic and stratigraphic distribution tab-
Wate” sapere seen seinen erate pacman eeane sats 102
type specimen figured...........-.---- Pl. XLVIM, fig. 2b
“linguloides,’’ discussed. . - . 498
TUUOTSSOTUIMGeSCLiD CO eee Eee EeeEer EERE teers een ee ee i 516

840

Linguletla linnarssoni—Continued.
general geographic and stratigraphic distribution tab-

(ME ehReeacuaosce sSpocedcosoeosucorscososescsosecones 102
type specimen figured. - Pl. XXX, fig. 14
ECTONGOUALIS; > CISCUSSC Cae eae eee eee 536
Jit qbbdys WeseeGacciaaccsscosscasescoos SBSew ECE aLSsGe00KR5 536
manticula, described... 517
compared with Lingulella arguta 5 478
Lingulella clarkei ....-.-.---- - 485
Tinguileila desideratiee. cen see eee eee 492
Lingulella granvillensis ....-------------------- 504
Lingulella ora 522
PANG WIELIORSUNLES eee ee eee ee 533
(Obolusiotindasee eee eee ee eee eee 411
general geographic and stratigraphic distribution
tabulated - 2) 222 se Se esters Se ses cee 102
grouped on the basis of the outline of the ventral valve. 470
type specimen figtired|.-.---.-.-.----.2----- Pl. XX, fig. 1e
visceral area (splanchnoccele) characterized. -.-.-.....-- 470
martinensis, described......5........-.---.-------- i 518
compared with Lingulella ferruginea. - 498
Lingulella tumida 537
general geographic and stratigraphic diiiamtbvattion
tabulated. Ssassccets = ig neaee ace sce ee eee ees 102
outline of ventral valve characterized.........-.---.- 470
type specimen figured . aS Pl. XXXVIII, fig. 1a
MAMOT; ;ACSCTIDCA 2S go eevee ope ee ee eee eee 519
general geographic and stratigraphic distribution
tabulated seo. seas oa 522 eee econ eee eee 102

type specimen figured - . Pl. XXXVI, fig. 3

mosta, Gescribedesecioese ee eee eines ce eee eee = 520)
compared with Lingulella mosia osceola. -.- - o2l

AN GULEN Gen SIG I= eee eee eee eee 532

Lingulella winona ....-.-- ee tee eso ae ae 540

Lingulella winona convera 540

general geographic and stratigraphic Gnsinaaiviion

tabulated saeeaeec= cement ee eee eee ee 102
grouped on the basis of the outline of the ventral valve. 470
type specimen not figured.

MLOSTIAOSCCOL0 AG SCL DEC ene eee eee eee ee 521
compared with Lingulella kiwrensis..-......-..--..-- 512
Lingulella randomensis..........--------------- 530
general geographic and stratigraphic distribution
WEI QUIEN Clas soon gercascassssosssoeeesgsesecersensos 102
type specimen figured . Pl. XVIII, fig.
ET UOUTOIUO SALE CTL ON Clete 521
general geographic and stratigraphic distribution
tabulated ten seers oaeee tne nine poe een ee neta ce ee 102
grouped on the basis of the outline of the ventral valve. 470
surface ornamentation characterized................- 470

type specimen figured -

_ Pl. XXIV, fig. 1a

MULLNOT Si | CESCIDEO eee eee eee aE 521
compared with Lingulella acutangula...-..-.........- 473
BIG UNGULELLONHEDEN Wrasse eee ee eee fee cee 506
Obolus ? sp. undt. f.. 423
candingltarealdiscHssed peeeee shee === ae Epa erases nae 304
general geographic and stratigraphic distribution
LENCE ol aaseronncass Saas ceo Seeman secescke nsec 102
type specimen not figured.
Peg oko; COSAM OG! --oescsscosesnde sosecasonecooeseas 522
general geographic and stratigraphic distribution tab-
Wlatedteeese-eeaceeences ee seatee soc ect eaten S 102

hypespecimen! figured sees. sees eee e
(ONE \CESCHIDE MM ccen sete asec eae memee cee cceine eee
compared with Lingulella wpis
Lingulella wanniecki
general geographic and stratigraphic distribution tab-
Wlated ese cen te ee omen crates es ee sciocnsemereeenes 102

type specimen figured..............-.... Pl. XXXV, fig. 9

Owen? idescnibede-se nasa ote saceee cee ceioc eee ce soe 523

compared with Lingulella wanniccki. 539
general geographic and stratigraphic distribution tab-

(late Ce remem tenses eateries a cen nae ene oe 102

type specimen figured_.._.......-......- Pl. XVIII, fig. 5b

visceral area (splanchnoccele) characterized........... 470

“? paliformis,’? compared with Lingulella 473

Menatienniiig, OSSCre Wem ee anne een one 523

compared with Lingulella cuneola............-.------ 488

Lingulella mosia osceola 521

STAG ULELLUISUITILLIS Sacer eee eee ee 533

CAMBRIAN BRACHIOPODA.

Lingulella perattenwata—Continued.
compared with Lingulella (Lingulepis) acuminata

3 MOEN oe costs cate Mae ae ae eee ae Sees 550
Obolus (Westonia) ella ....-....-.-.--.---------- 456
general geographic and stratigraphic distribution tab-
Mate nes oo seiscnaeseeece eee esas ce ae secede eeee es 102
generic and varietal reference of form referred to from
Texas, discussed 550
grouped on the basis of the outline of the ventral valve. 470
fypeispecimentiipured lass sess see ee eee eee Pl. XXI, fig. 1b
visceral area (splanchnoccele) characterized 470
phaon, described se-2 9 see sees en eae seer ee 525
compared with Zingulella cuneola.....-.....--.------ 488
general geographic and stratigraphic distribution tab-
Wlated << seseteeseeteeee ree ee eee eee eee 102
outline of ventral valve characterized.. 470
type specimen figured..........-..-- Pl. XXVI, fig. 1¢
“ninnaformis,” mentioned ...--..-- a oN ee ae M anc 548
pogonipensis, described a ozp
compared with Lingulella isse 510
general geographic and stratigraphic distribution tab-
ulated!.|Ae. essa n eee 102
type specimen figured . js Pl. XX, fig. 3
prima, described i c2- oe sastesce coe esc aee oe eee eee eee 526
general geographic and stratigraphic distribution tab-
lated’s.o 202 fee eee eee me eee Ve cohen see 102
type specimen not figured.
?primzuvas described ese esss i nee eee econo ee eeeeene 527
general geographic and stratigraphic distribution tab-
Milatedtasuc ce sete te Sesh ack Basaeee eo ce see eee 102
type specimen figured - : . Pl. XXXII, fig. 5a
punctata, described... -..--.-.-.-----=.- 528
compared with Lingulella arguta 479
Lingulella manticula..........-..-..------------ 517
discussed 517
general geographic and stratigraphic distribution tab-
WEY flo eee Bm eoss scameacaseseceussodceussoouscESeo
type specimen figured .......--...-..----.---

visceral area (splanchnoccele) characterized
quadrilatenalis, GeScribed as = amen see eee eee eee
general geographic and stratigraphic distribution tab-

qlated ches fh sade tet se eee ae oe eee eee mee ~ 102
type specimen figured Pl. XXXIX, fig. 6

RIM ih, ClO al g}ef6 |e Senn soo seoos ssehonsecsoszesencoseonods 529

compared with Lingulella bellula..........-..--.----- 482
Lingulella ferruginea.........-..-.-------------- 498
Lingulelia ino.....-.-------- 507
Lingulella martinensis.......-.----------------- 518
BGT ILG WELL OMIUILLILO TS Usenet ete teeta 521
Obolusicyanels dss scent eo tee see ee 389
Obolus fragilis 393

general geographic and stratigraphic distribution tab-
WAteG a oot See oe ere ee ee os 102

type specimen figured..........--......... Pl. XLV, fig. id

visceral area (splanchnoccele) characterized..........- 470

MOCTOLOS Den 1CLS CUSSEC se eee eee ee eee 529

randomensis, described. ..-....-.-------- 530
general geographic and stratigraphic distribution tab-

qilated sac sue Sees eae ee eee ti eeeeerin eee eens 102

type specimen figured... Pl. XXI, fig. 5

HOOT Hp (NEXT Gl ede eons essceogcesesessosssseos 530
compared with Lingulella desidera esas sak ene Seay 492,

JOA GAN GIB oo pons eoeddeneasonat saacessoo36 495
general geographic and stratigraphic distribution tab-
(WET ris AR ene emorcamatesaanqnarcneceqedconcoectioc soc 102
type specimen not figured.

SCHIECH Ent }ACSCRIDE Ceara eae ese ree eerie eee eae 530
cardinal area discussed........-.....- SP ree eae ee 304
compared with Lingulella acutangula.........-....--- 472
general geographic and stratigraphic distribution tab-

ulated se se. Je ccs See tee eee eae eee 102
generic reference discussed............-.-------------- 472,
oldest species of genus-.--2.-22--2--------2---=------- 531
type specimen figured... .- -- Pl. XXI, fig. 6

Stemiradzkit, described =.= sess eee ee see eee eee 531
general geographic and stratigraphic distribution

LEVI Gls ea Secccesecenedeceissossnocscenccasaces 102
type specimen figured... -- Pl. XXXI, fig. 2

Signata®) GeScribed aaee ace see eee een eee eee 532
general geographic and stratigraphic distribution

itabulatede 3a: cccn sees a sone a ea eee ees 102

INDEX.

Lingulella similis, described ...-.....-----.-------------------+--- 532
compared with Lingulella desiderata -- 492
Lingulella leos se) 14
general geographic and stratigraphic dasimismiiiom
TA OWI RWC oe condaccaseaneodbeccouascesEsosescoaes 103
type specimen figured_.........-.---.--..-- Pl. XXI, fig. 2
viscera: area (splanchnoccele) characterized. - 2 470

? simplex, described 534

general geographic and stratigraphic aesimionien
TOWING. ac sescsncecoospooesorosedecssscosEess> 103
type specimen not figured.

Tine, CESGM OG Se A doesso apo saceonmbsaee pas ncos=253= 534
compared with Lingulella franklinensis-..----.------- 502

STG ULELLONIL Seen eee eee eee 507
general geographic and stratigraphic distribution

(DOWIE 5 soc eseqced ance eeacocoonbAcesseasssosse° 103

type specimen figured... -..- ame Aeeine Pl. XXIII fig. 2a

terana, described 535
general geographic and stratigraphic distribution

iINMIEVEGL. oo oeceocemacconpssoerodosneoroesoeeoormce 103
type specimen figured....-...-.-.-.--.--. Pl. XLIX fig. 3a

LOMMEIIES I OSCLLD COs eer eee ate ate ee =e a eee ee ee 535
general geographic and stratigraphic distribution

tabulated.........------ Seeesine ea eer ee 103
type specimen figured Pl. XXXV, fig. 7

TBI Ps, GSM oe 2 3522 t ont cores See oseaes ease sco—a5 2 536
compared with Lingulella (Lingulepis) gregwa..-.---- 556

Lingulella (Lingulepis) longinervis.-.---.------- 556

Lingulella (Lingulepis) pumila. ..-.------------ 556

OWDRISE MPTGRIS on -necaesedconcessesssce3s2c58= 418
general geographic and stratigraphic distribution

tabulated maemeeeeene ee ta eee eee 103
intermediate between Lingulella (Lingulepis) gregua

and Lingulella (Lingulepis) longinervis.-.--..-.----- 556
type specimen not figured.

UT CSCLD CG eye eae eee 537
confused with Lingulella (Lingulepis) gregwa 537, 554
general geographic and stratigraphic distribution

(HANGER. = sce ces sSsceocosos esas resosassessee= 103
type specimen not figured.

“unguiculus’’ mentioned .....-...---.--------------------- 497

nis, CSG El. 2 soe e s ose eco sesesnesscemcoseeasesapase tes 538
compared with Lingulella wanniecki.........------- 538, 539
general geographic and stratigraphic distribution tabu-

IEG. we osceccssocses-seoceaccapaesscedsooracsesesoe 103
type specimen figured. Pl. XXXVI, fig. 3

wanniecki, described 538
compared with Lingulella fuchsi..........--.---.----- 502
general geographic and stratigraphic distribution tabu-

IBVIGGL. . oscsccosssso-sss cosssoccoesenesoessonesnoces 103
type specimen not figured.

ampellent, described: << = 25-2. = ao mw ww ne 539
general geographic and stratigraphic distribution tabu-

IEE ce nsscoescenoseoseeesses aco: sossesssasecensees 103
type specimen figured... -- Pl. XXXVIII, fig. 4

winona, described -....-....---.--------------------------- 539
compared with Lingulella winona convera..-.-..---.- 540
general geographic and stratigraphic distribution tabu-

IPNIOG|. 5- sae cos sogdoassoenccssososensocestesasosscoss 103
grouped on the basis of the outline ofthe ventral valve. 470
type specimen not figured.

winona convexa, described........--.----------------------- 540
compared with Obolus pheres........-..-.---.-------- 408
general geographic and stratigraphic distribution tabu-

IBN oancdae ose asaacesoore sotoossousrecensenesodene 103
type specimen figured........-.-..----- Pl. XVIII, fig. 4a

ATA, COMGM NC eos seta se seo sccase caste ssecs=sesc0e> 541
compared with Lingulella cedens...........-..-------- 485
general geographic and siratigraniic distribution tabu-

IBViCGl = -encedatecancscse Jobsoee ostsesscoscoorosedses 103
type specimen figured...........-.-.------ Pl. XXX, fig. 7

PETES ACES CIRCE Oey ate ee ee tet 541
general geographic and stratigraphic distribution tabu-

THO ee caopepennoemonauoooseaabonSsocarseaccsacEas 103
type specimen figured...........----------- text fig. 45, 541

Spend ta ay describe dee. =e meee ae eee eer 541
compared with Lingulella agnostorum. .-- 476
general geographic and stratigraphic distribution tabu-

IGGGO). so55sScconesnnquLssnuasposscossuenoabusToSeDe™ 103
type specimen figured. ........-..-.....-. Pl. XXX, fig. 13

Lingulella sp. undt. b, described...-..... EONS cccasccess . O41
general geographic and stratigraphic distribution tabu-
Ibias bane pacsoubeposcoorecasscs+05 Sco Se RE e ee eer 103

type specimen not figured.
sp. Kayser, discussed and compared with Lingulella davisi

phalel J. (Up Obemmaencaccssinastoosap2scc esse aesosSIa5o38 490-491
“(?) sp. Matley,”” discussed -..-..--..--.------------------- 703
ae (Leptembolon), described - . oe O41
ChaALACtehIze Cee ene ees eee eee eee ea 473-474
classification of.
evolution discussed

OYOUOIOM Oi. — cs eascéeosessezsoneseees
general geographic and stratigraphic distribution of
the species referred to..........--..--..------------ 103
general stratigraphic distribution and number of Cam-
brian species and varieties of......--.----.--------- 110
may include Lingulella ? insons 508
TMGIMOP ELS oa coscanssadscorsoeoteosconssoscanoceraus 378
number of species of, in different types ofsediment.. 160
type species “ Obolus (Leptembolon) linguleformis”.... 474
languilze foTs7S 1. CSCI eye eee eee 542
general geographic and stratigraphic distribution tabu-
DENIS toe a 2 A aS ae ee ene Bee aaceaSemecacict 103

type specimen not figured.
linguleformis solidus discussed
Lingulella (Lingulepis), described .--...-----
Characterized s:seesssce sae tses tee ee ee eres nae eee
GEENA NOM Oh. = caascesosee ssosoccoseeserseeteooes

compared with Botsfordia... 602
IDAHO. 55-92 2cenae39=50° 560
TANG ULCLUC ee sete etnies a 472
evolution discussed... .-.- 319
evolution of 317

general geographic and stratigraphic distribution of
the species referred to........-..--.---------------- 103
general stratigraphic distribution and number of Cam-

brian species and varieties of...........-..---.--.-- 110
mentioned.............---- 378, 471, 488, 557, 558, 559, 560, 668
number of Ordovician species and varieties of.......- 113
number of species of, in different types of sediment... 160
reference to, of Lingulella (Lingulepis) acuminata meeki,

GhSOHESOG | sass osonsccoscesosoescoodseeccesesesacase 550
relative position of vascular sinus in species of-...-..- 377
stratigraphic distribution of species discussed... ...... 545
surface ornamentation discussed 302
type species “‘ Lingula acwminata”’......-..----------- 544
type species of, discussed ..........-...-.---------- 547,548
young shells more elongate than adult shells.......... 473

acuminata, described -......--------..-.----.----------- - 545
compared with Lingulella bornemanni......------ . 483
Lingulella cuncola 488
Lingulella signata 532
Lingulella (Lingulepis) acuminata meeki-.- - 550
Lingulella (Lingulepis) acuminata sequens..... 55k
Lingulella (Lingulepis) exigua....-.....----- 553, 555
Lingulella (Lingulepis) gregwa ....--.--------- 555
Lingulella (Lingulepis) roberti 5 | ahy/
Lingulella (Lingulepis) rowei. 558
Lingulella (Lingulepis) squamosa o ase)
Obolella chromatica.......-.-.-------- 592
Obolus belli.......- - 386
Obolus rhea ... 411
Obolus sinoe . 545
Obolus (W estonia) rogersi........-.------------- 464

general geographic and stratigraphic distribution tabu-

type specimen figured
acuminata meeki, described. .

compared with Delgudetia lusitanica BcaascaneeneaTons 560
Lingulella (Lingulepis) eros 551
general geographic and stratigraphic distribution albe
WUC pdadoosdcosoonecdasaasneos eos seectus-oesee 103
type specimen figured...............--..---- Pl. XLI, fig. 2
acuminata sequens, described .......-.---.------------------ 551
general geographic and stratigraphic distribution tab-
WHOS Sdebeisiddhacoodéocceoncosasccaseos seebsooouS 103
type specimen figured............-.-.---- text fig. 46A, 551
acuminaia weeksi, merely an error in spelling. 550, 551
Gras, Goren oye Soc doc ssosebooaucasuscesonessseescesasasss 551

general geographic and stratigraphic distribution tab-
MEICo beso cesdaqsbScosoBEUeeHeonS oS et eebo ue eEaeas 103
type specimen figured..........-...-.. Pl. XXXIX, fig. 9

842 CAMBRIAN BRACHIOPODA.

Lingulella (Lingulepis) exigua, described ...........-..----------- 551
compared with Lingulella twmida.......-..-.--------- 537
Lingulella (Lingulepis) gregwa.......-.------- 554, 555
Lingulella (Lingulepis) longinervis F 556
Lingulella (Lingulepis) pumila. - 556
Lingulella (Lingulepis) roberti.....-. . 558
confused with Lingulella (Lingulepis) gregwa..-...- 554, 555
Lingulella (Lingulepis) gregwa_.....-..---.---.- 537
general geographic and stratigraphic distribution tab-
Wlated eeeeeee sree res - eC ene Ree eee eee eee Tees 103
type specimen not figured.
young shells more elongate than adult shells.........- 473
gregwa described... 554
compared with Lingulella atava:.. 480
Tring uel Canidae ae eee eee 485
EGU RULE LLORISS Chee eee eee EEE eee eee Eee eee 509
Lingulelia radula 529
Dingulellavtriparitrs 2 see. e- eee eee eee 536
Lingulella (Lingulepis) exigua.....-..-.-- 552, 553, 554
Lingulelia ( Lingulepts) longinervis.......-....- 555
Lingulelia (Lingulepis) pwmila.........---.---- 556
Lingulella (Lingulepis) roberti - ..- 558
general geographic and stratigraphic distribution
tabulated ieee je se cee eels cree ssp eee eee 103
type specimen not figured.
species confused with..............-.-.- 479, 480, 587, 554, 555
young shells more elongate than adult shells...-.....- 473
Gregwa Tobusta |GeSCrIDEG oye = es oe ee ee 555
general geographic and stratigraphic distribution tabu-
TENICG| ood sas posse Ges codipcecdoadesesraeb acne saa5sn 103
type specimen not figured.
‘longinervis, described. . 555
compared with Lingulella triparilis - - 536
Lingulella (Lingulepis) pumila....-..-.-.-.---- 556
Lingulella (Lingulepis) roberti .........-------- 558,
Obolus parvus 408

general geographic and stratigraphic distribution tabu-
Ibiolns SaeasodaasesuadnossedcasSoctsas ccesecosouaate 103
type specimen not figured.

pumila, described. --- 556
general geographic and stratigraphic distribution

UB NWEUHCL« oooc cosas sseos casas Sas sesossocesasssseoe 103

hype specimen he uined ene meee eae eee . Pl. XLV, fig. 3

AMG, CORSA FNC o-oo secs sess sea ssccsseoeseosecossee econ 556
general geographic and stratigraphic distribution

(OVUM ss oocbsdoscssdseseeeccobsceszoosroned 103

type specimen figured......--.- Pl. XXX, fig. 10

TONGUE, CESOM eel - 35 - cosseosnc see esonecsescescosssoreods+see 557
compared with Lingulella grandis .- - aes 502
LES AMO TT OO 3 ss io 93385250 20ee 3 45s2858es 509
JOY OENAIG TEM OUDTE 55 oo 2s00- cen secoss cone 518
general geographic and stratigraphic distribution
(AMIE oo cst con ssee steno cosssesdooseseonccesas 103
type specimen figured...--...-.---.-- Pl. XXXVII, fig. 4a
HOU, COO M16 o-oo osasaseosesseecnsosess0ssseseqn00er25 558
general geographic and stratigraphic distribution
(HMC. -o2cesteoss ose ssccesrescctosstonseuses 103
type specimen figured ................-.-.-. Pl. XXI, fig. 4
Sample, COMO MC. 5 asso nssaasees sso p9essz229sseonsIeon es 558
general geographic and stratigraphic distribution
TEE Cle cos sso sososesadosesasuascoucsossre aaces KIB}
type specimen figured...................... Pl. XIX, fig. 5
squamosa, described 559

general geographic and stratigraphic distribution
WIVES « con sobecsscoscoogsbussenspennosdeesnases 103
type specimen not figured.

starri, described 559
compared with Lingulella minor .... 519
Lingulella (Lingulepis) exigua 553, 554
general geographic and stratigraphic distribution
TA WIENEEl. . nooo ssecondonagoasonnoosdsodsodseeseosnes 103
type specimen not figured.
byDE IS PEGI N SY OSU etal alee eee ee eee eee 559
sp. undt., described 560
general geographic and stratigraphic distribution
talbwlated memes emer ee tne ste seer e eter ase meee y= 103
type specimen not figured.
“Tingulepis dakotensis,’’ compared with Lingulella cwneola.......- 488
“Tusitanica,” type of Delgadella 560

“matinalis,’’ name proposed by Hall.-........--.-.-.---.-- 401

“ Lingulepis’’—Continued.

“meeki,” specific reference discussed .....-.-..----.------- 550
Dire OTKg WNesMy WWE, = 2 2 52-2 eee seen escesscss 548
“pinnaformis,” compared with Lingulellacuneola........... 488
mentioned 401
Synonymy offorms referred to - - ---. 545-546
stand Val sen CISCUSSEC cere eee ene eee eee eee 554
(Lingulepis), see Lingulella (Lingulepis).
“ Tingulobolus affinis cwneata,’”’ discussed..-..-..-.--.------------ 432
(Lingulobolus), see Obolus (Lingulobolus).
Tinguwloids; shellistructurelofe-e eee eee eee eee eee eee eee 297
Dingulops mentionedpeeee eee eae eee eee ee eee eee eee ee ee Eee rece 297
platfonmymentionedseeeaseeeeeee ee eee ee Ee eee eee eee 309
Linnarsson, J. G. O., bibliographic references..........-.--.-.-.- 19
genus named) forvy ts -.e- Moe Sa ace eee sie aes coeeeeeee aes 666
SOCOES TRAE OS « Soe son sesecose assem es onesessonsmonsonss 516, 782
TANNATSSONELLC, GeSCLi be Ue see a ees tee e eee eee eee 665
cardinal area discussed.................------- aeat 305
classification of...... ee Aeeaess
compared with Dicellomus..-...--...--.-.---------+-- 572
Obol elles no caceeeee terse eae eee eee 314
Oboletla atlantica 314
Obolus 312
evolution discussed 319
evolution of 317
general geographic and stratigraphic distribution of the
speciesirefered tot Sassen sees eee eee eee ee eee eee 105
general stratigraphic distribution and number of Cam-
brian species and varieties of.............-..--.---- 111
miuscle)scars| discussed se seem se= eee eee eee eee 312
number of Ordovician species and varieties of-....... 113
number of species of, in different types ofsediment... 160
pedicle tube discussed! - 2-2-2222 eso = 314
reference to, of Linnarssonella tennesseensis discussed. 670
type species Linnarssonella girtyi............--------- 665
vascular markings discussed.........-.--.---.------- 311
“‘broadheadi,’”” discussed 666
Girtyi, AESCrIbeO))-2jeeeanee seo emeles see e eae eae 666
cardinal area discussed. .<----- 2-2-2. -ceesessseste-e= 305
compared with Linnarssonella modesta 669
Linnarssonella tennesseensis . . . - 670
Linnarssonella transverse. . 670

type of Linnarssonella. - :
type specimen figured............-...--
minuta; desceribediy. see nes ae oan cise seca eee

compared with Linnarssonella girtyi......--.--------- 667

669

669

105

Occurrencelmentione dee see ee eee eee ele 666
type specimen not figured.

modesta, described er sen scree ee aaee denen eeeeeeceeetee ae 668

cardinal area discussed. 305

compared with Linnarssonella nitens.......-.-------- 669

Linnarssonella transversa...- 670

Linnarssonella urania........-.-------------- «- 671

general geographic and stratigraphic distribution tabu-

seasereeeee 666
type specimen figured. -...... Pl. LX XVIII, fig. 8e
mitens4OeSCUDE Cis emenen seat eae eee ae eee eee eteiae 669

compared with Linnarssonella modesta. . sdaneo, Gas)
general geographic and stratigraphic distribution tabu-

LEN ICs Bea he berahccoparas cece eansaanserosauaadosocs 105

occluirmencelmentlOned pees see= eee] een ee eee eee 666

type specimen figured.......-....----- Pl. LXXVILI, fig. 7

LENNESBEENSISHGESCHIDE Cees = se nae eee eR eeee eee eee eee 669

compared with Linnarssonella modesta........--.---- 669
general geographic and stratigraphic distribution tabu-

Nate de ips ck iMag ctadioeieisip wierd steniee she weis sisimmeniomeies on 105

occurrence mentioned 666

type specimen figured................--
transversaidescribedmaceeneecreeeeen case een eee eee eee
compared with Linnarssonella modesta z
Linnarssonelia mitens\---- 2 = =~ 3-2 nce weno

: INDEX.

Linnarssonelia transversa—Continued.
general geographic and stratigraphic distribution tab-

PULL eGe clay nserseysie fers Kale Se Sey Ara tea a 105

Occuimencesmentione dese ees ee teen te eee eee eee eee 666

type specimen figured... Pl. LX XVIII, fig. 6

urania, described.............. 670
general geographic and stratigraphic distribution tabu-

Merb eevee teysterroe rae Seat are Pe ee oa Sec eee 105

‘occurrencelmentioned sae 2 sasseee ne sees eee tence eens 666

type specimen figured ..............-.
dinnarssoni, see Hoorthis and Lingulella.

“Tinnarssonia,”’ compared with Acrotreta.................-.----- 673
GISCUISSE Oe sameness cise Nel tetera ra 5 ee 666, 673

mentioned . 650, 691, 705

“belti magna,’’ compared with Acrotreta gracia_ 687

SUC ia DTELLOS M24 QISCUSSEG 1s saicisers ene ince ee eee 705
SLiostracus linnarssoni, association mentioned..............----.-- 531

steinmanni, association mentioned 499
ulrichi, association mentioned ........... 499
sp., association mentioned............... 499
si sansspecies mamedtonecen. ssae ee eeeeine cae see ace eee eee eeteee 693

disani, see Acrotreta.
Listrium, defined
iscUssed easter ge eee, See Dio Nei
Little Antietam Creck, Maryland, locality on...._.
‘Little Belle Island, Newfoundland, localities on
stratigraphic position of beds on, discussed ....-.......-...- 482
Little Belt Mountains, Montana, locality in 340f
Little Belt Mountains quadrangle, Montana, localities in. 4x, 5f, 5k, 340

Little Bras d’Or Lake, Cape Breton, localities near......... 30, 3a, 101
Little Conestoga Creek, Pennsylvania, locality on...............- 12v
Little) Metis; Quebec, locality at.._........2..-..2.-2------------- 392e

stratigraphic position of beds at, discussed -. aS
Little Rocky Mountains, Montana, locality in....................
eiversShowmin feUuress= yen scans sts seee-a eee os csioeeinc eee

Liverpool road, near York, Pennsylvania, locality on...........-- 49a,
Livingston quadrangle, Montana, localities in .. .. 4r, 148a, 302f
Lianberis, North Wales, locality in.................-...........-- 366e
Llandeilo shales (Lower Ordovician), in generalized section for
England, Scotland, and Wales, listing species and localities 135
lOCalIbies ims eyaen so ed eis eee nan Ree miomere acts one eee 316, 316a

Llano County, Texas, localities in.... 14b, 14c, 14r, 68, 68e, 68y, 68z, 353c

Lianvirn, in generalized section for England, Scotland, and Wales. 135
Llyn Dywarchen, North Wales, locality at ...............-....-- 366i
Localities, authority for citation explained....................... 328

explanatory statements .........-..-......-.-- 160-161

HtalicsHnlexplaine em. .jeseeeee eee eeceek cence en ceee eereeee 328,
OCA eS p22 (eer ters cera setae eal ee aiateiclorcle Sic sets rele eraser cine 161-229
ocalities!800-39625 och ese. ceccces ciceee sec sec = --- 229-286
ocalinesiGl—C (bese epee smoasee eee aeio ate tana eae wesc 286-291
Loch Maree, Scotland, localities near............ - 316c, 316d
Modenit7; Bohemia, locality ati. .----)--4--5---42--n-e eee eee 3030

Modi, Wisconsin, localities at_..-2-.-.-----.J2--c2-55---- 86, 328i, 3281
Logan, Montana, localities near........-....... . 4g, 4h, 4k, 4p, 302t

Logan, Sir William E., species named for......................--- 351
ogani, see Micromitra (Paterina).
Lone Mountain, Nevada, locality on....................---.-..-- 221
‘Long Island, Kennebecasis Bay, New Brunswick, localitieson... 2u,
2x, 308¢
Long Reach, St. John River, New Brunswick, localities on....... 2y
300, 301f, 308d
Long Point, Trinity Bay, Newfoundland, locality near........... 6w
-longinervis, see Lingulella (Lingulepis).
Woneitudinaliaxis, defined. -s-s-seeeee see asset e eee eee oe 294
Lookout Mountain, Eureka district, Nevada, locality on.... 56
Lookout Pass, Onaqui Range, Utah, locality near........... = SB

Loper, S. Ward, acknowledgments... ............-...-.--.-------- 13

SHOTOS MENACE) WYP. 2 -csecsoesosenszanconcessneanosatsonnsccs 396
SUpPFenus mamed one see ates se err eee ae eeee= se eeeeee ee eee 744
.loperi, see Obolus.
«(Loperia), see Protorthis (Loperia).
: L’ Original, on the St. Lawrence River, Canada, locality near... .. 3190
Los Negros, Spain, locality at 350b

Louga (Luga) River, St. Petersburg, Russia, localities on... 336u, 395z
‘Louise, see Lake Louise.
Louise, see Micromitra (Iphidelia).

Lovened, Sweden, localities at........-..-.-.---------- 310q, 320h, 320n

Low, A. P., species named for........-.-------------- Nessie eats ae 734
Low Hampton, New York, localities near..............--..- 34, 39, 45b
~“Lower black slates”’ (Upper Cambrian), locality in-............ 318m,

843

Lower Cambrian:
Alabama, generalized section listing included and correlated

(Syoletenel ebaval MOLERMMGES|. depose 4 socsc used Jeusencaonsee 147
Alberta, species and localities correlated with those of British
Columbia 32 V5.2 2 Sacer emer eases on 2 ts oa. 129-131
Bohemia, localities and species in listed.................... 124
British Columbia, detailed section listing species and locali-
BES 2a See abe Ree eas Se en ss 129-131
California, species and localities correlated with those of
Nevaldaysc one sie ou acd are Sa cieee iene tice saat rena u ane abd 137-138
Cape Breton, note on its absence............--.------------ 135
Denmark, generalized section listing included and correlated
Species|andllocaliticse sees = eee see ee eeE ene eee eee 146
England, generalized section, listing species and localities.. 136
families represented in, listed ....................-.-------- 112
Finland, generalized section, listing included and correlated
Speciesjandilocaliticspeeeee a eer eee eee eee eee Eee eee 146
genera identified in, listed ......................-...- 110-111, 317
Georgia, generalized section, listing included and correlated
Speciessandmlocalitiessseseer see sen eee ee eee eee ee ee eee eee 147
line of separation between Middle Cambrian and, in Cor-
dilleranijecioneeeeeeeeeeeeeereeeceeen Sac e Rc eeeeese 148, 153
Nevada, detailed sections, listing included and correlated
Species/and Jocalitiesmees--sn--eeedeee ess. eeee seas 137-138, 140
INH SDH Ws) TOV Wid... Ange scoosees doom aeduseewbcoese 135
Newfoundland, detailed section, listing species and localities. 141
Norway, generalized section, listing included and correlated
Speciesjandilocalitiess-me-reeeeseeeeee eee eeeeeeeeeeeeeee 146
Russia, generalized section, listing species and localities.... 144
Scotland, generalized section, listing species and localities... 136

Speciesiirom))discussede--eetensseeneeeeeeeeeeraene eee eeen 316, 318
species from, listed 89-109
Sweden, generalized section, listing included and correlated

SESS Hal MCCANMIES 6 6 oon casecascosoncesosseossosecsacece 146

Tennessee, generalized section, listing included and corre-
lated species and) localities: ---+-----.-----.--.------.--- 147

Utah, detailed section, listing included and correlated species
Miiaandilocalities sys yuna iene ve Ne ees Lan oa panies 158
Wales, generalized section, listing species and localities.... 136
“Lower graptolite slate’’ (Passage beds), locality in.............. 390f

“Lower lenticular layer” (‘“‘Linsenschicht’’) (Passage beds), in
generalized section for Russia..........-..--..-------..-. 143
localitieshinjonneahasreees es aaaseeeeree cere aareneeace 396m, 396p

Lower Stockingford shales, in generalized section for England,
Scotland, and Wales, listing species and localities......_. 135

lowi, see Nisusia (Jameselia).
Lucinia divaricator, surface ornamentation discussed.............- 301
Luga River, see Louga River.

Lugnas, Sweden, localities at...................-.----------- 309d, 390j
Luh, near Skrej, Bohemia, locality at....................-------- 345e
Lumparn, Aland Island, Finland, locality near_................. 3lle
Lumparstr6mmen, Aland Island, Finland, locality near.....:..... 311d
ihn Sweden localities means ase eee seers sence ees aaa 309,

309a, 309h, 309i, 310t, 320d, 321s, 321t, 321z, 390b, 390g
lusitanica, see Delgadella.
iby ckssBastperussia, localitysileates =e een eee Pee ee Seer ee eee eee
lyncioides, see Orusia lenticularis.
McAdam shore, East Bay, Cape Breton, localities on.... 10r, 325, 372d

McAphee’s corner, Hardingville, New Brunswick, locality at..__. 301s
McCodrum Brook, Cape Breton, localities on and near........_. 3i, 344n
meconnelli, see Obolus.

meconnelli decipiens, see Obolus.

meconnelli pelias, see Obolus.

McCoy, F., bibliographic references .......................----.-- 19, 20
McGill post office, Nevada, locality near........................-- 313

McGill’s ranch, Nevada, locality near....................._....-. 8p
Me Grezor lowes Ocalii yaa aee ee eee aa ny eae nes
Mackenzie Basin, British Columbia, locality in...................
McKinley Canyon, Caballos Mountains, New Mexico, locality in.. 327%a
McLean Brook, Cape Breton, localities on....... 3i, 10s, 10t, 307f, 307g
McLeod Brook, see Barachois River.

MeMinn County, Tennessee, locality'in...................-...-.-. 128a,
MeMullins Brook, Cape Breton, localities on........!......... 160, 372e
MeMullin’s place, Cape Breton, localities near. 3p, 10d, 372b
McNaughton Corner, New York, locality at................. es 45a
MeNeil Brook, Cape Breton, localities on and near 3h, 307i, 325a
MePhees; Cape\Breton, locality at--.------2----------4--.-----0-- 344j

McPhees Brook, Cape Breton, localities on and near....._.-
McPhees Point, see Youngs (McPhees) Point.
macra, see Nisusia (Jamesella) perpasta.

10p”, 307b

844 CAMBRIAN BRACHIOPODA.

maculata, see Acrothele.

Madison, Wisconsin, locality near.........-.-..---.-------------- 85z
Madison County, Missouri, localities in... ....- - 11j, 369f, 369h
Madison County, Montana, locality in... PRO BAsSPEASseacHedhs 149a
Madison Mountain, Montana, locality at......-...-..-...-.------ 302w
Maentwrog, North Wales, localities mear.---..-.----.-------- 3181, 318m.

mera, see Obolus.

magna, see Acrotreta sagittalis.
Maiden Arm, Hare Bay, Newfoundland, locality at.....---- feces 314g
major, see Billingsella, Micromitra (Paterina), and Rustella.

Malad City, see Malade.

Malade, Idaho, localities near.........-.-------- 4y, 5a—c, 5h, 54s—x, 55d
maladensis, see Micromitra (Iphidelia) pannula.
Mallada, L., bibliographic reference...-_.-...-....-.-.-----+:---- 20

Malmohus, Sweden, localities in... 309, 305a, 309b, 309e, 309h, 309i, 310h,

310t-z, 320d, 320j, 320k, 321s, 321t, 321z, 323], 323k, 390b, 390¢

Malvern Hills, England, localities in...--.-....-.-.------ .. 304, 304a-¢
Malvern “‘quartzite’’ (Lower Cambrian), in generalized section for
England, Scotland, and Wales, listing species and locali-

TIES ose eee See eee ergs 136
localities sinS:= 2. S42 ose sete sete \-cis seein ee saree eetaee 304c, 304d.
Main vascular canals, shown in figure .. Barada seeeeenee 374
Mammoth, Utah, localities near..--...._.. -.-.-.. 34n, 34s
Mammoth limestone (Middle Cambrian), localities i in......... 34n?, 34s
Manitou, Colorado, localities near_..-.... 186, 186a. 187, 360a, 360f, 360¢
manitouensis, see Selieanibon:
manticula, see Lingulella.
Manto shale (Lower Cambrian), localities in.............- C3, C17, C20
Manuels, Conception Bay, Newfoundland, localities near. ....... 5p, 5r

Manuels Brook, Conception Bay, Newfoundland, localities on.... 1, la,
2, 3, 61, 6n, 6r, 6u, 6v, 41, 314h

Manuels Brook section, in detail, listing species and localities.... 140-141
species associated with Lingulella ferruginea in.....-....-.. 498
Manuels Brook section, 6 (Middle Cambrian), localities in.... la, 61, 6n

Manuels Brook section, 7 (Middle Cambrian), localities in. . J 1,2
Marble River, New York, locality on.......-.-.-.--.-.-----..---- 111
Marchillyn-mawr, North Wales, locality at............-.-.--..---- 366e

Maree, see Loch Maree.
Mariehamn, Aland Island, Finland, localities in.. 311f, 311q, 3llw, 31ly

Marienwerder, West Prussia, locality near..........-.--.---.--.-- 3861
Mariestad, Sweden, localities near................-..--.----- 309d, 390j
marion, see Billingsella.

Marion Bridge, Cape Breton, localities at and near-..-........... 3h,

3i, 3n, 10s, 10t, 11z, 307g
Marjum limestone (Middle Cambrian), in detailed section in House
Range, Utah, listing included and correlated species and

localities sys =ceeo seer cee me eeaee seh oe aeacres semenesee 155-156
localities in. -..-- 3w-y, 8i, 10y, 10z, 11n-q, 11x, lly, 15c, 30g, 30z
Marjum Pass, House Range, Utah, localities near......--.......- 3w,

10y, 10z, 11n, 11p, 30h, 30j—n, 30n’, 300, 30w, 30z, 31t
marjumensis, see Acrotreta.

Marthas Vineyard, Massachusetts, locality on.....-....-......-.- 326

martinensis, see Lingulella.

Mary Dingle, England, localities at-.-..-....-...--.......... 304h, 304i

Maryland, Cambrian species of, listed.........-..........--..-- 114-119
localitieswms reece tenses cece ee encase rics 16f, 47d-£
note on stratigraphic position of localities in................ 159

Maryville limestone (Middle Cambrian), in generalized section for
Tennessee, Georgia, and Alabama, listing species and lo-

calities 147
locality in. peel 23
Massachusetts, Cambrian species of, listed..-.......... .. 114-119
first notice of fossiliferous Ordovician pebbles in...........- 464
loonie tia ee oenobeeeopodacenscsscausonne 5, 9n, 326, 326a-g¢
matthewi, see A crothele.
matthewi eryx, see Acrothele.
matthewi lata, see Acrothele.
matthewi multicostata, see A crothele.
Mathews, E. B., (Clark, W. B., and], bibliographic reference... . 15
matinalis, see Obolus.
Matley, C. A., bibliographic reference. ............--.-.....--.-.- 20
Matthew, George F., acknowledgments. - ¥ 12
bibliographic references... ..-.-.- - 20,21

RSTO S $00 5001 © CLT ye eed er 649
Maxfield Mine, Big Cottonwood Canyon, Utah, localities near.. 33i, 55u
maximus, see Obolus apollinis.

Maynardville quadrangle, Tennessee, locality in ....-.-..--...... lla
Mazomanie, Wisconsin, localities near..........--.--.-- 85x, S85x, 328p
Mazouka Canyon, California, locality in.-................--..-..- 176a

Meagher County, Montana, localities in. ..--......-.-.--- 5f, 5k, 9h, 340

Meall 4 Ghiubhais near Loch Maree, Scotland, localities on.... 316c, 316d

Meath, Ireland, locaity in... ---+--.-.---2-- 2.22 Sik See aes 317a
Mecklenburg-Schwerin, Germany, localities in.........-.-.-..-- 386e-¢
Median ridge; Shown In figure. 2222. . 2522 sees eee eee eee 374
Medianisep ttm cdetine disses = see seen ssse-eee ee eeee see eeeeee 294
showniinifigure® st .6 epee nee er cere eee eee ee 374
Meek, F. B., bibliographic references. -5---22.2-2----2----- 21
speciesinamed!for.= 5. 4yose tastes cee eee ese eee cee 550
Meek, F. B., and Hayden, F. V., bibliographic references. ......- 21
mecki, see Lingulella (Lingulepis) acuminata.
“ Meekina prima,” discussed 669
Megalaspis planilimbata zone, in generalized section for Russia.... 148
See also Planilimbata limestone.
Melinda Ferry, Tennessee, localities near.......- 9a, 101, 101a, 101b, 102
membranaceus, see Obolus.
meneghinii, see Obolus.
Meneyian group, in generalized section for England, Scotland,
and Wales, listing species and localities. ...... WOE oe Bers 136
mentioned oc Fehon eee see ee ee ena eee eee 723
species associated with Lingulella ferruginea in 498,

Menevian (Middle Cambrian), localitiesin - 318d-f, 318h, 318j-1, 318p, 318r
Menomonie, Wisconsin, localities at and near.. 79a, 80, 82a, 100, 134, 1344

Mercersburg, Pennsylvania, locality near-...........-...-.-.----- 346b
Merionethshire, North Wales, localities in... 305f, 318, 366a, 366f-q, 366s
Meseritz, Germany, locality mear-----.-----.---------+------------ 386h

Mesonacis torelli zone (Lower Cambrian), in generalized section for
Sweden, Denmark, Finland, and Norway, listing species

and localities. =< footer eae tecet es eee eee ne eee 146
Mentioned si F s Pesan essen desae eee seen eee eee 596.
locality in

Metadoxides, association mentioned...............----------------- 584

Metis; Quebec; locality-ato-. ..-- 2. -. dee sseeee see eee eee eee 319h
stratigraphic position of beds at discussed .....-.....-..-..-- 705
See also Little Metis.

Mettawee quadrangle, New York, localities in............ 22a, 38c, 338v

Mettawee River, New York, localitiestoneeeseeee near eee eee 20, 21a

Meyer’s mill, near Emigsville, Pennsylvania, locality at.......... 49

Michigan, Cambrian species of, listed..........................- 114-119

localities tiny a ens5 cee eece teense eae . 330, 330a, 330b

pee aceee 159

note on stratigraphic position of localities in

Mickwitz, A., acknowledgments......-.....-.-..-...........-..- 11
ibibliopraphicreferen ces tees eeenee ese ree ee ee eee 21
<enus MamMedtOnee see eae tessa eee 329
mentioned! 2.2 acevescece scence 367
minute discriminations by, discussed 378

species and varieties of Obolus and subgenera recognized by,

AMR Ussia NStedia eee cee esas ase eeeoe eee eee eae 380:
species named for. -..
subgenus named for. . -

( Mickwitzella), see Obolus ( Mickwitzella).

mickwitzi, see Obolus.

Wickwitzia, described s ca scese ae seee one enna ease once eee
cardinal area discussed
classification iofe: vecasce2 2382 nce ee see seers
compared with Helmersenia-. ~~ ~~ 2-2-2222 eee eee 368

DCnOMIUT OS eee eee

Schizocrania.
evolution discussed - -
evolution ofe 222 (222 5. Seca eee eae neon eee ees

false cardinal area mentioned....................-...- 318
general geographic and stratigraphic distribution

of the'species referred to ---:.--222-23--2-2------2- 98
general stratigraphic distribution and number of Cam-

brian species and varieties of. -...---......--.------- 110
muscle scars not shown in...-...- 312
number of species of, in different types ofsediment.... 160
surface ornamentation discussed
type species ‘‘ Lingula ? monilifera”..........---..---- 323

[epithets COM CEO. 552 ee aseosseensenebseescessireod-soces 329:

compared with Mickwitzia monilifera.......-..- 329, 330, 331
general geographic and stratigraphic distribution

tabulatedeeassee seer eeeeee

type specimen figured.......--
monilifera, described.........--------
cardinal area discussed ..
compared with Helmersenia ladogensis.
Kutorgina perugata

Mickwitzia formosa

Mickwitsia pretioza............ Wind apesoasmDaens 332

Mickwitzia sp. undt

; INDEX.

Mickwitzia moniliferea—Continued.

general geographic and stratigraphic distribution
tabulated so. 2 hiatal. Steestecceseies eee eee 98
type specimen not figured.
pccidensdescnibed maa -en eee e encase tone eee oreo eee 331
compared with Mickwitzia pretiosa.....-.-.-------- 331-332
general geographic and stratigraphic distribution
tabulated ........... ye 98
type specimen figured. pee LAG AE vate, 2
MiclLosa td eSchibedesseeaseeee eee nese eee eee eee eeeece 332
compared with Mickwitzia monilifera.........-..----- 332

Mickwitzia occidens.
general geographic and stratigraphic
bajoulatedts ss ce)sc ae eeitiodaseiance soacee cet oeeee 98
type specimen figured.

Spalndtesdescnibed asst ae eeereeeeeeeneeeaeseee ans - 332
compared with Lingula rouaulti ........- 332
Mickwitzia monilifera, 332

general geographic and stratigraphic
Lab Wiatedee seem nanan toe cee aacrceite eee eee 98
type specimen not figured.
WMickwitzia conglomerate (Lower Cambrian), in generalized section

for Russia, listing species and locaiities...........-...--- 144

in generalized section for Sweden, Denmark, Finland, and
Norway, listing species and localities ............-.------- 146
HOCalitypiny awe nas sree soe ee ees aaa neeee emer ere 396q
Microdiscus connexus, association mentioned...........--.------- 707
Microdiscus punctatus, association mentioned ......... - 498,707
Micromiira, described 332

apical depression, slit, or foramen in species of, dis-
cossedmeeeeeeeee gas Stee ee eeateaecneee 334, 335, 366

cardinal area discussed

classification of.

compared with Alcrothele.--..--.------------------- 631, 632
PAlCrOLNELEMM COM OTE Taal seise a eet 661
Acrotreta ? cancellata. as 679
Curticia.......--- 318
Kutorgina....- 580, 582
LTNNOTSSONELL Mean eee seen cicero 665
Mickwitzige nat aecs cetenck sale S-icaseeea-e 329, 330,331
Schizambon ? esthonia 622
IVOLDOTERiG tes me eae eee eeepc 366

delihymitimdiscusse dsesereesee sense ee esas eee 318

evolution discussed....-....-.-.-.----- Be 318

evolution of...-...... 3 317

general geographic and stratigraphic dis

ithe}species retermedstOeee = eer eee Ree eens 99
general stratigraphic distribution and number of Cam-

brian species and varieties of 110
interior of, unkmown..........-.---.-....- 333
mentioned.........--- .- 316,344,349, 357, 359, 361, 674
muscle scars not Shown in...-.-.-.-.-............... 312
notes on use as a generic name 334, 341
number of species of, in different types of sedi-

WSN = csocossogscescage cooccosessemesszessaqooasese 160
oC GOV MIEINCE), « .-ssssc0 voces onteosesssesesesenetoees 297
species referred to, listed ..............- 336
stratigraphic distribution.........--- 336
surface ornamentation discussed _ 801
Systematic position discussed ............---..-.--..- 335
type of ornamentation characteristic of........- 333, 335, 336
type species Micromitra sculptilis, - -...- - 333,330,336

QICUOTTULET SS AO eS CTIDEO eee eee ee ee ee 337
compared with Micromitra (Paterina) labradorica

CRU NENTS ooconssecassnconoscossesssens2esesenscese 349
general geographic and stratigraphic distribution

VE MEE psosscossc cose setoseceseosdcoseooscesaa 99
type specimen figured -. Pl. I, fig. 5

haydenr, described. =. .--se--55 eee oe 337

compared with Micromitra sculptilis....-.......--.-- 341

general geographic and stratigraphic distribution

tabulated 99
habitat mentioned - - - 159

type specimen figured ..... - text fig. 20A, 338

CASES, CESOM IC nec eccsceose hss beep sacasceoseoce = eebecasbs 338
general geographic and stratigraphic distribution

abuls ted eee =en eee eee ene ee Ree Reet eter ees 99

type specimen figured ..... .-- Pl. II, fig. 10

me ealers Cescribe diesem crater scenisecnaenieriae cece eee 339

apicall’slit in) discussed): --)-- 22222222. --.-oesee--=-=2 == 335

Micromitra pealei—Continued.

compared with Linnarssonella girtyi...-.-.....------- 666
VGCTOTTVUNOANUESULS ete ee et 338
Micromitra (Iphidella) lowise..-.---------------- 359
Micromitra (Paterina) crenistria.....-.--------- 335
Micromitra (Paterina) stuarti....-..-.-.-.------ 356

delthymiumlld iScusse desea eee eee ese eae 318

general geographic and stratigraphic distribution
tabulateditseeeeenee see ee terre eeer eer sear 99

surface ornamentation discussed...........------ == Biol

type specimen figured.........-..----- Pl. III, figs. 3, 3a-b

pusilla, described 339
ASSOCIATION CNilONe Cee ease ee ese seer 340
compared with Micromitra scotica......-....--------- 340
general geographic and stratigraphic distribution tab-

ulated Se eeebe nS: aaa ee eee ne fee eon aee SaaE eS aCeea 99
type specimen not figured.

Sscotica, describedts 7a. te ieceias see ee ce ae ee eee 340
association mentionedes: 222.222 ss see ssee sees see eee 340
general geographic and stratigraphic distribution tab-

TWabedseeeeeeereee Beis 99

type specimen figured ss 21A, 340

sculptilis, described.......-...-..----.- ‘ie tele es Sore eee eee 341

compared with Micromitra alabamaensis ....-.------- 337
Micromitra sculptilis endlichi 342
INGORE, EY UCTD os once secs=50s300025002° 338
WW AGRO TO DUST on oe shacnsoscgssoseoaearesae 338
SMGCTOMIUN OM PCCLE tetera eta 339
Micromitra zenobia.........-------- 342
Micromitra sp. undt.....-.-.--.---- 343
Micromitra (Iphidelia) pannula........-.-.--- 362, 363
Micromitra (Paterina) labradorica............--- 335
Micromitra (Paterina) stissingensis -.. 303,354

general geographic and stratigraphic distribution tab-
Wlabed eS. Sees as seco eases ete ue sa loeneeeee 99

labeling of type specimen described 334

stratigraphic distribution.............-.-..--.-- sige 336

surface ornamentation characterized... - 333, 335, 336

surface ornamentation discussed...............-.----- 301

type species of Micromitra.........-...--.---------- 335, 336

type specimen figured.........--....-.----.-- Pl. TI, fig. 5

SCULpiSenalich (CeSChiDe deeeeee eee ee eee eee eee eee eee 342
general geographic and stratigraphic distribution tabu-

TENG sn oe cone ciosastemeeoncbocmasAanmetugeontaansaae 99

type specimen figured.................--... text fig. 22, 342

zenobia, described 342
compared with Micromitra (Paterina) stissingensis.... 354

Micromitra (Paterina) stissingensis ora........-- 304
general geographic and stratigraphic distribution tabu-
datedines see ce ottetad ta aatec acts Seaherec 99
type specimen figured -.

ab WiAChin, ClIOMC ocean ccoosscorecdaccoseseescemsoaeecco
general geographic and stratigraphic distribution tabu-

JET Rae omad se Sa arrosanertdee shoceshtancHaarcmne tec 99

fypelspecimen figured tessa esse ese -ee ee =e Pl. III, fig. 7

Micromitra (Iphidelia), described 359
apical depression, slit, or foramen in species of dis-

|CUSSOC Het eo een pe fara a ee oe eee eR er 334, 335

elassification|o ieee =e ees == seer ree anaes ea- eal, 322)
compared with Obolus and Rhinobolus..............-. 335
evOluplom Ole a- ese eels aes etc = ce eae as cee 317
general geographic and stratigraphic distribution of
the}speciesie tered Ope esses aes eee eee eee 99
general stratigraphic distribution and number of
Cambrian species and varieties of . eel LO!
interior of, described so far as known..............-.- 333
number of species of, in different types of sediment... 160
SPeciesprefereds tO; IS ted sees ese see nee eee 336
stratigraphic distribution of-......................- 336, 337
surface ornamentation discussed. ............-.------ 301
systematic position discussed. ...................-..- 335
type of ornamentation characteristic of........---.. 333, 336
type species “‘ Trematis pannulus”.........--.------- 359
Lowises described tn. oyu mrseine= shencue a fee eae oe steeeee 359
general geographic and stratigraphic distribution
ita ulated rise et) va hemes Sie iejne mans che is)Sie cisers Lise 99
stratigraphic position discussed. - -. 359
stratigraphic position mentioned................---.- 316

surface ornamentation discussed. . . 301
type specimen figured.......-.......-...- text fig. 31A, 359

846 CAMBRIAN BRACHIOPODA.

Micromitra (Iphidelia) nyssa, described. .......------------------ 360
compared with Micromitra (Iphidella) lowise......---- 309
general geographic and stratigraphic distribution

UE NOU EN Io ee Sea Gros socaconscesocascserocesorocsoes 99
stratigraphic position mentioned ....--.----.-.------- 359
surface ornamentation discussed - .---..-..-..-----.-- 301
type specimen figured Pl. III, fig. 9

OT MUTL ELI. CS CID C0 eee se ee 360
apical foramen in, discussed. .-..--...------------- 334, 335
apical opening in embryonic stages discussed... -...-. 335
area in dorsal valve mentioned .....-. Oi Ls EUG eee L 334
association mentioned...-......-.-------------- 340
compared with Micromitra (Iphidella) nyssa 360

Micromitra (Iphidella) pannula......-.------- 335, 362
Micromitra (Paterina) bella.....-..-.----------- 334
Micromitra (Paterina) labradorica swantonensis. 334
Micromitra (Paterina) wapta....-..------------ 357
general geographic and stratigraphic distribution tab-

Wlatedlc smoot Ghee eee see ee ye eee meee 99
interior of, described so far known.....- --- 333
surface ornamentation representative 336
type specimen not figured.

HUT, GEST CO mete = ate a l= 361
apical ‘depressionyine seeseee area ee ee eee a 335
area of dorsal valve described - - - - . 334, 335
cardinalareaGISCtisse dees eens= see seme eee 303
compared with Acrothele bellapunctata.......--.---. 633, 637

Botsfordia pulchra..........-.------------------ 602
Discinolepis granulata........------------------ 664
Kutorgina perugata 584
Micromitra alabamaensis 337

Micromitra (Iphidella) nyssa......--.-----------
Micromitra (Iphidelia) ornatella... -

Micromitra (Iphidella) pannula ophirensis..... 365

Micromitra (Paterina) bella ........------------ 334

Micromitra (Paterina) labradorica swantonensis. 334
delthyrium discussed .:....-....-.------------------- 318
general geographic and stratigraphic distribution tab-

HIB OG hoc oso acscasceees ses oss soSese saceecsenann0 99
habitat and distribution mentioned - . 159
stratigraphic position mentioned........... 316.336, 355, 356
surface ornamentation characterized........--.- 333, 336, 341
surface ornamentation discussed 301, 302, 336
type specimen figured..........-. Pl. IV, figs. 1g and 16

varieties of, characterized ............---------- 363, 364,365
pannula maladensis, described.......----.------------------ 364
(HOE PCUEOCGL. - 5 oo sceososcoacboseoscodee seosessas _-. 363
compared with Micromitra (Iphidella) lowise...--.-.-- 359
Micromitra (Iphidella) pannula...-...-.-------- 363

general geographic and stratigraphic distribution tab-

TIStedeeneer eee eee eee eee eee ee see ere eae 99
type specimen figured.................-..--- Pl. IV, fig. 2e

pannula ophirensis, described. 365
characterized 363
general geographic and stratigraphic distribution tab-

WIR Al. =) saeaoseqnet ose oss souswooseeesebsoanaosS 99
interior of, described so far as known. --..--..-...---- 333
stratigraphic distribution. ...-.....-...--..--..---- 336, 337
type specimen figured.......-...-..--..----- Pl. IV, fig. 4a

Micromitra (Paterina), described.....-..-...--------------------- 343
apical depression, slit, or foramen in species of, dis-

GUSSOGl sSacbsccsaneeseons 334,335
classification of. .... - - - 821,322
GOWN Oh oo-co2se5s2 sess seq eeeos cee scoessecessoss 317
general geographic and stratigraphic distribution of

the species referred to............-.---------------- 98
general stratigraphic distribution and number of Cam-

brian species and varieties of...........-..------.-- 110
interior of, described‘so far as known. --.---.-...-..-- 333
number of species of, in different types of sediment... 160
species referred to, listed.........---...--------- -- 336
surface ornamentation discussed. 301
systematic position discussed.......----- 55.) Sb
type of ornamentation characteristic of - - -- 333,336
type species discussed.........--.--.--------+----- '. 336,344
type species Micromitra (Paterina) labradorica swan-

MUDOIRGS = aescec cos tose oot cone suSsEconespasscosendS 344
GAMO AE. eo oGoesaSsooescanssooecebesnescosdeSEEoseS 352

Micromitra (Paterina) bella, described............-.-.---------.-- 344
apical foramen in, discussed 334, 335, 345
area in dorsal valve not seen .........-.----.--.---.-- 334
carginal’ area discussed ----_2----.-------- 2-22
compared with Micromitra pealei Z

Micromitra sculptilis....-.-------
Micromitra (Iphidelia) ornatelia. -- P
Micromitra (Iphidella) pannula..-+..--------
Micromitra (Paterina) crenistria......-.-.------
Micromitra (Paterina) labradorica
Micromitra (Paterina) superba ......---.----
general geographic and stratigraphic distribution tab-

wWlated 2252. soso St ee eee 99
not the type of Micromitra (Paterina)....--.--------- 336
surface ornamentation representative........-.------- 336
type specimen discussed.....------- --- 335, 345, 350
type specimen figured...............---.----- Pl. II, fig. 1e
type specimen (7) referred to Micromitra (Paterina) |

UNG)» oo o2ca03202222525032952292228225550025 335, 345, 850

crenistria, described 345
compared with Micromitra pealei.....--.-.----------- 335
Micromitra (Paterina) logani.. ...-.-.-------- 345, 350
Micromitra (Poterina) stuarti ........---.-.---- 355

general geographic and stratigraphic distribution tab-

WAGE sone tenccoecceseos Breer eonee ea gneeseee 93
type specimen figured .....-..-.-..-.-- Pl. IL, figs. 4, 4a—b

etheridgei; described: 42222 es.ee ss -2 eter see sence nee eee 346
general geographic and stratigraphic distribution tab-

Wated)s 2-53 se fooae soa eeae ee eee emer 99
type specimen figured-. . Pl. IL, fig. 10

labradorica, described sess ss eae ese ae ee 347
area in dorsal valve mentioned ...-.-..----.----------- 334
association mentioned..-.......----------------------- 328
compared with Kutorgina...-..-.--.----------------- 333

Micromitra alabamaensis ......-.---------------- 337
WUE CTO CCIE tee eee eee 339
WMacnomeiniy puUsill Oren see ee eee ae 340
Micromitra scutptilis 5 SR
Micromitra (Iphidella) nyssa...-.-.-.----------- 360
Micromitra (Paterina) bella.....---------------- 334
Micromitra (Paterina) crenistria...-...-------- 345
Micromitra (Paterina) labradorica swantonensis. 349
Micromitra (Paterina) labradorica utahensis.... 349
Micromitra (Paterina) labradorica var. undt... 30
Micromitra (Paterina) major...--------------- 351
Micromitra (Paterina) phillipsi...-..---- - » 352
Micromitra (Paterina) stissingensis : 353
Micromitra (Paterina) superba.....-- 356
Micromitra (Paterina) undosa........-.------- 357
Micromitra (Paterina) wapta.....--.---------- 357
general geographic and stratigraphic distribution tab-

(HEN ab eecberine coat mec heeesosetsenscasdesosese 99
interior of, described so far as known..-..------------ 333
notes on generic reference of 334

stratigraphic position mentioned........-....------
surface.ornamentation characterized
type specimen figured......-....-..-.--------
labradorica orientalis, described ......-----------------------
compared with Obolus obscurus
general geographic and stratigraphic distribution tab-

THEN A 4 specndetowocoseasoseest conesdcdsoscdatens 99
type specimen figured...........------------- Pl. II, fig. 11
labradorica swantonensis, described ....--------------------- 348
compared with Micromitra alabamaensis- 337
Micromitra (Iphidella) ornatella......-.--------- 334
Micromitra (Iphidelia) pannula...-.----------- 334
Micromitra (Paterina) labradorica.. - - 347
Micromitra (Paterina) labradorica orientalis.... 348
Micromitra (Paterina) labradorica. utahensis.... 349
Micromitra (Paterina) prospectensis .....--.--- 353
general geographic and stratigraphic distribution
tabulated is meses neeee ees eee ee eee ee ee teeta 99
surface ornamentation representative. .....----------- 336
type of Beecher’s genus “ Paterina”’ . -- 334,344,349
type species of Micromitra (Paterina)...--.----------- 344

type specimen figured........--.-------------
labradorica utahensis, described
compared with Micromitra (Paterina) stuarti.....---- 355

; INDEX.

Micromitra (Paterina) labradorica utahensis—Continued.
general geographic and stratigraphic distribution
tabulated
type specimen figured.........-....
ldbradorica var. undt., described
general aaenyo ate and sitaligraphic distribution
tap ulated isa eee tee tes Sis ioe ee eee eee 99

LOGOUT COSCRID EO peste eiaeeiesiascosee cise eise issn nee see ee 350
cardinal area discussed 303
compared with Micromitra (Paterina) crenistria..... 345,350

Micromitra (Paterina) stuarti........----------- 355
founded on type specimen (?) of Micromitra (Paterina)
350

general geographic and stratigraphic distribution tab-

IVa beGde Meee ote oS aon bk So ase ee ee 99
the type (?) of Micromitra (Paterina) bella. .--.-.-
type specimen figured .......-...-..--.-

NUL ONAOCSCLI DEO iss iaicae = os see eeyaj= sees wae See ee ee eee
confused with Obolus smithi..........-..-------------
general geographic and stratigraphic distribution tab-

Wate dyer sens cee sume sasioueeeseteet eeaee Gene 99
original description included specimens now referred

351

to Micromitra (Paterina) williardi........---------- 351
typespecimen figured -.-----..----=-.2.---- text fig. 25, 351
Dil s), GeSCLibe Wisma == assesses 351
confused with Kutorgina cingulata.. - 352

general geographic and stratigraphic distribution tab-
plated: 26) a tee foeaeid esse ect Soka Sen neces 99
type specimen figured............-.....------ Pl. II, fig. 8
prospectensis, described
compared with Micromitra (Paterina) wapta.....-.--
general geographic and stratigraphic distribution tab-

type specimen figured .
stissingensis, described .....-...-------------

compared with Micromitra alabamaensis....-.-.------ 337
Micromitra (Iphidella) pannula......--.-------- 362
Micromitra (Paterina) stissingensis ora. -- 354
Micromitra (Paterina) wapta.......-.-.-------- 357

general geographic and stratigraphic distribution tab-

type specimen figured
Stissingensis ora, described.....-...------------
general iareeratte and stratigraphic distribution ‘ibe

, Bl, i, fig. 1

type specimen not figured.
stuarti, described
general geographic and stratigraphic distribution tab-
WBE s ease stsownsosceeneEaecos JoOOS COSA EEEaEeB bes 99
stratigraphic position mentioned...........--..--.-
type specimen figured
superba, described............-.-------- a nae eevee cnnhe
apical(slit:absent season ciceite - cnicecele case ese as

Cardinallareal discussed mere seressa et eeeeEeeeeeseee eee

compared with Micromitra pealei 339
Micromitra (Paterina) bella. -.- 335
Micromitra (Paterina) crenistria .....-----.---- 345
Micromitra (Paterina) etheridgei ...-.-.-.-.---- 346
Micromitra (Paterina) labradorica utahensis.... 349
Micromitra (Paterina) williardi ....-.....---.-- 358

general geographic and stratigraphic distribution tabu-

pseudodeltidium in ventral valve described ......-.--

334

stratigraphic position mentioned.-.........-....... 355, 356

type specimen figured .. Pl. Il, figs. 7, 7a-b

AU OSC eSCH DC Oe er eee ee eee eee eee 356

general geographic and stratigraphic distribution tabu-

ate diersersyya racials aetna ers cite nam sacar ele a aeere 99

type specimen figured ---
wapta, described --.......-.---
confused with Acrothele@olleni....-..--------.--------

357

type specimen figured - é
Mpilliardisidescnibed|. irs. -sa--h cee ae oe et ieee aee

confused with Micromitra (Paterina) major..-..------ 351
general geographic and stratigraphic distribution tabu-
Tabe Cee eer is yn wins Snare at Suh caeiee ak IRN pan nies RES 99

847

Microscopie shellistricthune= 2 =o = 2 = aoe ene ei 297-300
microscopica, see Acrotreta.

microscopica missouriensis, see Acrotreta. |

microscopica tetonensis, see A crotreta.

Middle Cambrian, Alabama, generalized section, listing included

and correlated species and localities. ..-...-.-.--.-..----- 147
Alberta, species and localities correlated with those of British
GColtim bias Seer ae eee eee eae eee meas 126-129
Bohemia, generalized section, listing species and localities.. 124
British Columbia, detailed section, listing species and
localitiesi: 32s ee ete ce sees errr tena eee eee eres 126-129
Cape Bretoa, generalized section, listing species and
localitiess 222 Sak io Sees Be eee carne ate eeteie erate eee 131-135
Denmark, generalized section, listing included and cor-
related specrs and localities. ...............-...--.----- 145-146
England, generalized section, listing species and localities.. 136
families listed teresa sets erecta eine eee eee Enea 112
Finland, generalized section, listing included and correlated
SPeCies an GelOCAICS Seese ee eee ee eee 145-146
genera listed 4.2262 8e coos cee eis stn Ree ees 110-111, 317
Georgia, generalized section, igittags included and correlated
iSpeciesiandelocalitiesaeesn ae ee ee eee een eee ae eens 147
line of separation between Lower Cambrian and, in Cor-
dilleran resigns erie seca eo eee ee ane ees 148, 153
Missouri, generalized section, listing species and localities.. 137
Nevada, detailed section, listing species and localities... 139-140 .
New Brunswick, species and localities in, correlated with
(thoselofiCapesBretonee == seer ee eee eee 131-135
Newfoundland, detailed section, listing species and
localities asses eeeeee PgR MINCE ee SS AS NSE yy ee 140-141
Norway, generalized section, listing included and cor-
related species and localities. ...............------------ 145-146
Scotland, generalized section, insti species and localities.. 136
SPECIES PUISLC Mey penne sete eee soe eae eee eee 98-109
Sweden, generalized section, listing included and correlated
species and localities... 145-146
Tennessee, generalized section, listing included and corre-
lated/speciesjandvlocallittiessssess-se- seep este aeaeee eee 147
Utah, detailed section, listing included and correlated spe-
clesiand#localitiestsa- ssa epee re ec ee aor aee ase 149-153, 154-158
Wales, generalized section, listing species and localities.... 136
Middle Granville, New York, localities at and near_...... 22a, 38c, 338v
Middle lateral muscle scar, defined 294
showmiiniieurel. earn ae eee ae ace cee eee eee 374
Middle ZLingula flags, in generalized section for England, Scot-
land, and Wales, listing species and localities............. 135

Middle Mountains, see Mittelgebirge.

Middle Popo Agie Canyon, Wyoming, locality in.........-......-
Midsummer Hill, Malvern Hills, England, locality on
Milinsky Wrch, near Woleschna, Bohemia, locality at.
Milk Ranch, Clifton quadrangle, Arizona, locality near
Millard County, Utah, localitiesin.................-.----.-------

3s,
3t, 3w-y, 4, 8g, 8i, 8k, 10y, 10z, 11n—-q, 11u, llw-y,
14y, 15b, 15c, 30d, 30e, 30g, 30h, 30j-n, 30n’, 300,
30w, 30y, 30z, 31q, 31s, 31t, 31v, 33 1, 33n, 33r, 105t¢

Mill Canyon, near Liberty, Idaho, localities in and near_......... 55¢,

56f, 56g, 59f, 59g, 163
Mill Creek, near Landusky, Montana, locality on 302z
Millen SACs bibliorraphi cmetenren Cesee assesses anes eee 21

Mine Lamotte, Missouri, localities at........-....-.--.-.--...- 11j, 369h

Mineral Hill, Eureka district, Nevada, locality on......-......... 57b

minima, see Acrotreta-

minimus, see Obolus and Obolus lamborni.

Miniska, see Minneiska. ‘

Minneiska (Miniska), Minnesota, localities near................ 99, 339f

Minneiska (Miniska) River, Minnesota, locality near...:......... 339h

Minnesota, Cambrian species of, listed... .... - 114-119
localitieshines ianauaycem eee ee ieee teen eee Saree ceca 82b,

82c, 84, 84a, 84f, 84s, 97, 97b, 97s, 97x,
S97x, 98a, 99, 113, 131, 339, 339a-k, 364, 364a
note on stratigraphic position of localities in................ 159
minor, see Acrothyra, Lingulella, Obolella, and Obolus.
minuta, see Acrothele and Linnarssonella.
Midsen, see Lake Midsen.
Miquel, J., bibliographic references. ......-...............---.---- 21

SPECIES AMEUMOLA- Eee Sacer tras spleen spie BEE Rae ne 612
miqueli, see Yorkia.
Mira River Valley, Cape Breton, localities in...-...........---.-- 2c,

307c, 307f, 307g, 307i, 325a, 344n

848 CAMBRIAN BRACHIOPODA.

mirandus, see Obolus.
misera, see Acrotreta.

Mississippi River, localities on.......-.--..---- 99, 328¢, 339e, 339f, 339i
See also Wisconsin and Minnesota.
Mississippi Valley, only one species of Acrotreta in upper part... - 711

Missisquoi Bay, Quebec, locality on....-..--.--..---------------- 392m
Missouri, Cambrian species of, listed 114-119
generalized section of Cambrian in, listing species and

LOE Sate eee 137
IeARES Mls eoosessossse-cossco5-205 11d, lle, 11j-m, 369, 369a—h
missouriensis, see A crotreta microscopica.
Mittelgebirge, Poland, locality in.........-.----.-.--------------- 368a
Mjésen, see Lake Mjésen.
Mieschitz=)s ohemia ocalityallsese sete eee ease see ae eae 345¢
Moberg, Joh. Chr., acknowledgments . 12
bibliographic references... .-.-- 21
species named for 598
Moberg, J. C., and Segerberg, C. O., bibliographic reference. ......- 21
mobergi, see Obolelia.
WWTP, GUIGUINOL. 5 5b es s- 252 sobs saseescSanteoss0nsa0225 602, 607
modesta, see Linnarssonella.
Moel-y-gest, North Wales, locality at............---.------------- 305a
Moffat, Scotland, locality near........ Bee A 316
Moller, V. von, bibliographic reference . oe 21
Money UitallOcallitiy, m Cait ee jee eet ae eee eee eee 14t
monilifera, see Mickwitzia.
Monobolina, compared with Obolus and Elkania.....--.--.------ 378, 410
Monobolina plumbea, discussed 410
Monomerella, Hall and Clarke on development of_..-...---------- 309
Pplaformemen tole Meee ee see sneer re eee eerie 309
Montagne Noire, France, locality in-.......-..-...--.------------ 342
Montana, Cambrian species of, listed ...--.....--..-.----------- 114-119
localities in (Lower Cambrian). 4y, 4w, 5j
_ localities in (Middle Cambrian) 3j, 4g, 4h,

4k, 4p-q, 4u, 4x, 5f, 5k, 8j, 9h, 9k, 9m, 149a, 155a, 156a, 159,

302, 302a, 302b, 302k, 302s-t, 302w, 302z, 340, 340a, 340e, 340f
localities in (Ordovician). ---.--- - 302]
localities in (Upper Cambrian)
147a, 148a, 150a, 151, 15la, 152, 152a, 152b, 153, 153a, 154, 155,
156b, 157, 158, 158a, 160, 160a, 161, 302f, 302n, 302q-r, 340b

stratigraphic position of localities in, discussed. ........-...- 137
Montana, Missouri, localities near.-.........-.......---.----- 11d, 369e
montanensis, see Clarkella.

Monte de Valbom, Alemtejo, Portugal, locality at....-........--- 351
Montevallo, Alabama, localities near.........---.------- 14la, 142, 164f

“Montevallo shale”? (Lower Cambrian), in generalized section for
Tennessee, Georgia, and Alabama, listing species and lo-

GAMES — <2. -c0c sone ococ aso Sore soneosace co sccessoseSsocS 147
@@MMMES nih... - 22. 5s sas2 ese ness sessessesesorssacssese5 17b, 56c¢
Montpelier, Idaho, localities west of. ....- 5bc, 56f, 56g, 59f, 59g, 163, 322
Montreal Island, Canada, locality on - 319n
Morenci, Arizona, locality mear..........-.-.----------.-..---.-.. 358
Morgan County, Utah, locality im---...-....--..--.--.-.-.-.-...- 329¢
Morgans Creek, Texas, localities on -- 70, 70a, 70e, 3538a
Morris, J., bibliographic references. ......-...-------------------- 21
Morristown quadrangle, Tennessee, localities in... 103a, 103b, 104, 374a

Moses Hill, near North Greenwich, New York, locality on_....... 43
mosia, see Lingulella.
mosia osceola, see Lingulella.

Mossebo, Sweden, locality at.....-.--....--.---..---------------. 390f

Mountain Island, Minnesota, localities on. - -. 339e, 339i

Mount Billingen, Sweden, locality on........--...--------------- 321p
See also Billingen.

Mount Bosworth, Alberta, localities on...-.........--.--..----.-- 35c,

35g, 35h, 57c, 57d, 57g, 57k, 57s, 57y, 58z
Mount Bosworth section, in detail, with included and correlated

SpeciesjandsloCalinles = areaere eee eee eee nae eee 125-131

Mount Delano, Montana, locality near-. Misti ie ave aes cha 4r
Mount Dennis, British Columbia, iln@albiey i MOAT Sah seer ee eee 58r
Mount Field, British Columbia, Burgess shale on, mentioned .... 127
localittity MEP... s22sceg sory de 2590s 22 See ose eoseosssegeecesess 35k
Mount Helena, Montana, locality on.........-.-.-.-..-.-.---.--- 302s
Mount Holly Gap, Pennsylvania, locality at-............-.-..... 49f
Mount Nebo Canyon, near Mona, Utah, locality in. 14¢
Mount Stephen, British Columbia, localities on_............-...-- 14s,
35f, 57e, 57f, 57j, 57m, 57n, 57r, 58j-1, 58p, 58r, 58s

- Ogygopsis zone in discussed.........---.------------------- 127
Mount Washington, near Bau Claire, Wisconsin, locality on... ... 78a
Mount Whyte, Alberta, locality on...............-.-------------- 35e

Mount Whyte formation (Lower Cambrian), detailed section, list-

ing included and correlated species and localities. ...-- * 129-130

localitiesin .... 35c, 35e, 35f, 35h, 57e, 57m, 57r, 57s, 58k, 58p?, 58s
Mount Zion Church, near York, Pennsylvania, locality near....--. 496
multicostata, see Acrothele matthewi.
Munkesten, Sweden, locality at.........-.-......--.--!.-..- 320e, 321q
Murchison, R. I., bibliographic references.........-.--.---------- 22, 23
Murphrees Valley, Alabama, locality in-. 89
Murray, A., bibliographic reference. . tise 22

species named fort n2s22- ne aeses tone soe eee eee eee eee 406
murrayi, see Obolus. =
Musele\scars;detenminationofeesesesece see e eee eee eee eee 460

discussed

Muskrat Spring, Stansbury Range, Utah, localities near....-.--
32g, 32j, 32k, 320, 34u, 34v

Nahant, Massachusetts, localities at.....--........----.----- 326c, 326g
“Nahant limestone” (Lower Cambrian), locality in............-- 326¢
namouna, see Obolus. }

Nankiang River, China, localities on........-...-....-----.-- C32, C32
nanno, see Lingulella.

Nant-y-groes, North Wales, locality mear...........-..--.-------- 366m

nanus, see Dicellomus.
Nirke, see Nerike.

Narragansett Bay, Rhode Island, locality on........-.---.------- 343
Narwa, Esthonia, Russia, localities at..............-.--.---- 386s, 336z

localities west of....-.-..------- 337f, 3376, 395d, 395k, 395q, 395t
NathorstwAniG=speciesmam econ ee ese a eee 521
nathorsti, see Lingulella.

Natrona County, Wyoming, locality in....-.-........----.--.--- 3020

Natural Bridge, Virginia, locality near

nautes, see Nisusia (Jamesella).

Navy Island, St. John Harbor, New Brunswick, localities on. 308, 308a

Neanic; defined)s: 25 2-;s-2scse8 eee ass Gece cee See eee 295

Nebo Canyon, see Mount Nebo Canyon.

neboensis, see A crotreta.

Neihart, Montana, localities near..........----.--------- 4x, 5f, 5k, 340

Neoboline, classification of 321, 323

genera and species referred to described-. -. 564-567

‘Neobtolws; described is <a. -S2stteceec oe Se Se See aeons See 564
cardinal] area discussed............-.--.-.----------- 304, 305
classification of......-
evolution discussed. -
OVOlUBONKOL c22 5 S242 oases ee eee eee eee eee
general geographic and stratigraphic distribution of

theispeciesireferced tosssea- esse ae eee eee eeeee 103
general stratigraphic distribution and number of Cam-
brian species and varieties of.........-...--.-.-.--- 110
Hall and Clarke on development of...........-..--.-- 309
number ofspecies of, in different types ofsediment.... 160
Dlationmsmentionedass=—s—s- eee ee eee ee eeeee eee seee 309
warthi, described 566
compared with Obolus apollinis..........-.----.------ 564
Giscussed =: FS -gs oss eead es Ses Soe se eee eee 566
general geographic and stratigraphic distribution tabu-
lated).2< <2 estes oet ee eee 103

type specimen figured. -.......- . Pl. LXXXI, fig. 2f

Qu noes SUAVE ogo scosseesuessosscosponteessos2bssc 567
Neobolus beds (Middle Cambrian), localities in........-...... 357, 357a-c
Neotremata, cardinal area discussed ---- 304-305
Classification/of: ---2222-s2s2+-s2ese- eee 321,323

294

distribution in Cambrian strata...........-..-.-.----------- 316
evolution of genera of, discussed............---------------- 319
holoperipheral growth of pseudodeltidium in - 306
muscle scars compared with those of Obolus.........-.---- 312, 313
miusele|Scars\ CiSClISSEG sase= == aa eee eee eeeeeeee 312-313
pedicle tube discussed...........-.---- 314-315
surface ornamentation discussed.........-.-.--------------- 302
Wascilanmn ankin psidiscussedeese ese aenee tees ee eee 311
INepiomic, defined ae a5: 55) eer tee eae eee eee 294
Nerike, Sweden, localities in... ..-. eee ere seects 320u, 320v, 320z
Newhof, Germany, locality at 303f

Nevada, Barrel Spring section, in detail, listing included and cor-
related species and localities.--.-.-.--..-..--...-.-...-- 137-138
Cambrian species of, listed....--....-- 114-119

detailed section of Cambrian and Ordovician in, listing in-
cluded and correlated species and localities...........-. 139-140

detailed section of Lower Cambrian in, listing included and
correlated species and localities.................-.....-- 137-138

; INDEX.

Nevada—Continued.
Eureka district section, in detail, listing included and cor-

related species and localities..........-.-...-- . 139-140
note on Middle.and Upper Cambrian localitiesin...........- 137
localities in.............---.- 11-m, 1p, lv, 41, 7i-k, 7n, 7r, 7s, 7v,

~ x, Ty, 7z, 8a, 8b’, 8e, 8f, 8m-p, 8r, 10w, 14m, 30, 31, 31a,
$1u, 52, 54, 55, 55b, 56, 57,57b, 58, 59, 60, 61, 62, 62a, 63, 64,
65, 66, 174c, 175, 184, 201, 201a, 202, 203, 203a, 204, 205, 206a,
209, 211, 214a, 214b, 216a, 221, 313, 3138a—-k, 333, 333a—b

species and localities in, compared with those of Utah...... 153-158
Nevado de Castillo, Argentina, locality at -. 3894
Newberry, J.S.,speciesmamed for.........-...-2-----+---0-2----- 784
newberryi, see Eoorthis.

New Brunswick, Cambrian species of, listed........-.-..------- 114-119
localities in . 2e-i, 2k—m,

2s-u, 2x, 2y, 3a, 3b, 300, 301, 30la—n, 301s-z, 308, 308a-i
species and localities in, correlated with those of Cape

BYRON «con cocanoeda=acese Sen souboonSeaoDoceSspOoSs0e00 131-135-

Newfoundland, Cambrian species of, listed.......-.......------- 114-119

detailed section of Cambrian in, listing species and localities 140-141

localitiesamey ese aen-c ss ace 1, la, 2, 2a, 3, 51-p, 5r, 5t, 6g-i, 61,

6n, 6r, 6s, 6u-w, 6y, 41, 41a, 114, 114a, 114b, 314, 314a-i

Manuels Brook section, listing species and localities -..... 140-141

New Jersey, Cambrian species of, listed ........-.-..----------- 114-119

No calityeinbe eee eee eeee eee saiane matics Sse dL Le

New Mexico, Cambrian species of, listed ---- 114119

localitiesdmescs- = - secs s asec sees at ..-- 327, 327a-c

Newport, Rhode Island, localities near.............-.--- 343, 343a, 343b

Newton, New Jersey, locality at........-.-.0-2.------e-eecesenes- 1lc
newtonensis, see Hoorthis.

New York, Cambrian species of, listed ---- 114-119

localities in (Lower Cambrian)........-.- 2b, 2d, 20, 20a, 21, 21a,
22, 22a, 27, 27a, 29, 29a, 32, 32a, 33, 33b, 34, 34a, 35, 35a, 36,

36b, 37, 37b, 38, 38a, 38c, 39, 39a, 43a, 44a, 44b, 45a, 45b, 72,

72a, 338, 338a-h, 338k-q, 338x, 338y, 367, 367a, 367b, 367i, 3671?
localities in (Middle Cambrian) ...................-..---..-- 367d
localities in (Upper Cambrian)....-. 76, 76a, 77, 108, 109, 110, 110a,
111, 136, 185, 185a, 338j, 338r—u, 338w, 367e-h, 367j-k, 392b

localities in (Ordovician).........- 43, 338i, 338u, 338y, 338z, 367¢
note on stratigraphic position oflocalitiesin................- 141
New York Canyon, Eureka district, Nevada, localities in.. 54, 55, 58
Nicholson, species named for.....-....-----------seceeeeceecees 522, 696

nicholsoni, see Acrotreta and Lingulella.

Ninewells, near St. Davids, South Wales, locality at............. 318p

ninus, see Obolus tetonensis.

hisus, see Micromitra.

Nisusia, described
articulating processes discussed

cardinal area discussed -.-..---.-2---cceceneecnceese
cardinal process discussed.......

classification of......--..........

compared with Billingsella.... 306
Geltidiumy discussed pees eeeeneeiseceeciesecneneereceeme 306
evolution discussed... - 2... -- cee ec emcee cece ncn cene 319,320

evolution of

general geographic and stratigraphic distribution of the
SIOCOIAS MAINE! 1D) concen secssonsenetescouscaeseccs 107

general stratigraphic distribution and number of Cam-

317

brian species and varieties of.. 111
TaUsSclescarsiqiscusse deere eae seers eee eee eee eee 313
number of species of, in different types ofsediment... 160
pediclelopenine absentee ee ssasee eee eee eee eee ee 315
pseudospondylium discussed...............-.-.-....- 307
reference to, of Nisusia ? vaticina.................... 730, 731
reference to, of Nisusia ? (Jamesella ?) kanabensis dis-

GUSSEG EE ee sen eninin ee Se eine stain eee ne see eee cise 732
stratigraphic position mentioned....................- 318
type species ‘‘ Orthisina festinata”’..........-.-------- 725
vascular markings not preserved.................-.-- 311

ibertindescripedespincses a2 eect. amen enen caaice ons 726
compared with Nisusia rara...-.--.-2--2.e-eeecee--- 729
PNZSUS70) (cMOMMESCLLD) LOWL= =e a eee ee cicsie = seeeeee 733
Nisusia (Jamesella) nautes ...-..---+--.-+------ 734
Nisusia (Jamesella) perpasta ...-.....-+-------- 736
Nisusia (Jamesella) spencei......--.---.------.- 738

general geographic and stratigraphic distribution tab-

RULER INS Eis IPL My er NIN (ae ea RP Uys erat 107
surface ornamentation discussed.......-...-....-.--- 302
type specimen figured............-..---.----00 Pl. C, fig. 3¢

62667°—vor 51, pr 1—12—_54

ENE SUS7 cq COMUDLM, CeSCrUDE Cie ie\ateytae tells eine eee == = == 727
general geographic and stratigraphic distribution tabu-

Tate d yaee oe eye Boece Deena ae eee nica sists oi 107

type specimen figured............-.----- Pl. XCVII, fig. 14

festinata, described ........-.-.-...--- 120,

compared with Kutorgina 580

Nisusia alberta. -..-- 726

INU CUNO sooccceencidoocsebassojondosaoese 726

INEST) WOM = oso saccoeesdolqsooneconacsess08a9 729

Nisusia vaticina.... 730

Nisusia (Jameselia) . - 731

Nisusia (Jamesella) amit. 731

Nisusia (Jamesellz) lowt....-.------------ 733

WATE Dito a Ol ua temtceneaoodouN aconedaasS seal

Wynnia warthi. Bis peak

Cruraligmidiscussedeese= see eee en eeeee eee e eee eee 309

dentaliplatesidiscssedese sere tesa per eeeeetereye 310-311
general geographic and stratigraphic distribution tabu-

TAs Se Reece eee Cae ter Abo BAG SobS eeEaenoe 107

shell section figured............ .... text fig. 6, 299
surface ornamentation discussed. ..........---------- 302
type specimen not figured.
festinata transversa, described. ---...-----....---.-.---.----- 729
general geographic and stratigraphic distribution tab-
CoE i Seo eB Rope eacOesSde OC BUDAC Cece eEaer ob 107
type specimen figured.........-.....--..-----5 Pl. C, fig. 4
TATA GESCRIDEM Ee seigae eae tse ceeaae tee see Series canes ae ae 729
general geographic and stratigraphic distribution tab-
ulated sco ay/
type specimen figured. - . text fig. 60, 730
Pivaticina) CeScribedsassntee seeder sctis eee toese 730
general geographic and stratigraphic distribution tab-
OE eC ee acs Gab a eae ch eAos SaEeRcer arc rseteccares 107
type specimen figured............. Pl. XCVII, figs. 3, 3a-b
Nisusia (Jamesella), described 3 731
cardinal process discussed......-...-.---------------- 306
Classifica viOntOleeese erent tae seeee eases ase 321, 325
evolution of 317
general geographic and stratigraphic distribution of
the}speciesieferne dbo Samer semen aes eee eee 107
general stratigraphic distribution and number of Cam-
brian species and varieties of.........-.-.....-..-.- 111
muscle scars discussed 313
number of species of, in different typesofsediment.... 160
pedicle opening absent...-......................--.-- 315
reference to, of Nisusia ? (Jamesella?) kanabensis dis-
Gbssisln Sosa scbhaseneeseue qeeseunoee baaceoeeseation 732
reference to, of Niswsia (Jamesella) pellico discussed... 735
stratigraphic position mentioned 320
vascular markings not preserved 311
amii, described 731
general geographic and stratigraphic distribution tab-
Mlape ds Sse nematic setae el oniateia cereale evcraaree eee ee 107
type specimen figured.................. Pl. CI, figs. 6, 6a-b
CAB, CET CHI 90 a ees ae soso soos oaS ae eee ee ssSo-escebedee 731
general geographic and stratigraphic distribution
tabulated

Giditty GESOMI Cl oc osecescaonsossssosbecasesecceomonecedens
general geographic and stratigraphic distribution

UOT oA easceosnssssobencos ces segasceeadeon 107

type specimen figured -- Pl. CI, figs. 5, 5a-b

(MOAI OTE, ORSON... ce obo2 essa sece ss soossessac Jeeeee0 732
general geographic and stratigraphic distribution

HME | oe odaceoosaconjdossecmnouescmoddance BOCe. 107

type specimen not figured.

(SMH, COSINE. - ones Cosme ee eeecosss 732
compared with Wisusia (Jamesella) amii 731
‘ Nisusia (Jamesella) perpasta..........--.----.-- 736
. general geographic and stratigraphic distribution
UE ODOT A the Soeae Sarena Berbbr BESE DE acaeete 107
type specimen not figured.
Nowi, described 733

general geographic and stratigraphic distribution
babUlatede peers. sense es ec Mee apne Men. ots 107

type specimen figured ................ .- text fig. 61A, 734

MULULES \AeSCHIPC Mee sae ns fe eye sce eec ee pciieeeicciee secteenee ae 734
compared with Hoorthis thyone........-...--.--------- 790
Nisusia (Jamesella) spencei............--------- 737

ET OLONEH ISH UNG Use eee ic e-tkes ee oe nee casas 743

850

Nisusia (Jamesella) nautes—Continued. a
general geographic and stratigraphic distribution tab-

Nol soeeenoe aodoeaecocmsSscontcoecosecsesesssece 107

type specimen figured.......-..-------- Pl. XCIII, fig. 6

pellico, described ...----.--------------------------2+2-2---- 735
general geographic and stratigraphic distribution tabu-

(Enel soe oo oe ses ce cag sconnacoscsoossesssasceasese 107

type specimen figured..-..-.-..----.-.- Pl. XCVII, fig. 2

perpasta, described...-.-.-.------------ 735

compared with Nisusia alberta. 726

Nisusia festinata.....----------- 729

Nisusia (Jamesella) perpasta macra.....-------- 736

* Nisusia (Jamesella) perpasta subquadrata...-- 736, 737
general geographic and stratigraphic distribution tabu-

107

type specimen not figured.

perpasta macra, described ...-.-.---------------------------- 736
general geographic and stratigraphic distribution tabu-

DEG aos sno sscmod andetosacnaesessoncousceueuesusoees 107

type specimen figured. .......---.------.--- Pl. Cl, fig. 3a

perpasta subquadrata, described......----------------------- 736
general geographic and stratigraphic distribution tabu-

MAIC. oc ocodbsabone sas seqackosowestagocsssonccoaeep 107

type specimen figured ...........-..--------- Pl. CI, fig. 2a

spencei, described.....--.------------------+-+2+--22------- 737
general geographic and stratigraphic distribution tabu-

TENG oo dese ssséancooce Bs tel auspeee recat eters. 107

type specimen figured.....-.-.---------- Pl. XCIII, fig. 7a

utahensis, described. -..-...-.-.---------------------------- 737
general geographic and stratigraphic distribution tabu-

WEHIsl oot ad onseconasuecusbences aouosusasooceseeedg 107

type specimen figured............-.-- Pl. CI, figs. 10 and 10a

Sp. Undt., describes ae oem = eee we em 738
general geographic and stratigraphic distribution tabu-

! TWH oo obec sedessacee=ceasoSeropacaseSoISeseOng 107

type specimen not figured.

Nisusiine, classification of.
genera and species referred to, described .
surface ornamentation discussed.......-......-.. oeSc600009 303

nitens, see Linnarssonella,

nitida, see Acrothele.

Neersnzes, Norway, locality at.....-.--..-.-------------- piece cets of

Noetling, F., bibliographic references.............-..------------- 22

Nolichucky shale (Middle Cambrian), in generalized section for

Tennessee, Georgia, and Alabama, listing species and lo-
GONNOS. 52 csceee caote soon oso soserseoe seer soceonsssBSanenes 147
IOGAMINES Tid oaoe oso ost soessosceessscs 2z, 124, 124a, 374¢

Noémmeweske, Esthonia, Russia, localities at. .-- 396j, 396p
Nordmannaskar Island, Sweden, locality on -..-......-........-- 390b
Norfolk County, Massachusetts, localities in.....- 5, 9n, 326b, 326e, 326f
Norrskedika, Sweden, locality at-...-.....---.------------------- 3l1la
Norrtelje, Sweden, locality near....-...-..----------------------- 31lu

North America, zoologic list of Cambrian species of, giving geo-
graphic distribution by States and geologic provinces .. 114-119

zoologic list of Ordovician species of--....---..--..------- 122-123
North Attleboro, Massachusetts, locality near....--....---------- 326d
North Chatham, New York, locality mear...........------.------ 44b
North Granville, New York, localities near...----..------------ 22, 38a
North Granville bridge, New York, localities near.............- 20, 21a
North Greenwich, New York, localities near. 33, 33b, 43, 338c, 338e, 3380
North Hebron, New York, locality near........-..----..--------- 34a
North Weymouth, Massachusetts, localities near... 9n, 326e, 326f
Norway, Cambrian species of, listed..-.-...---..------.----.--- 120-121

generalized section of Cambrian and Ordovician in, listing

included and correlated species and localities........... 144-146
localities im._......-.-. 8v, 8x, 9f, 323, 323a-i, 323 1-z, 324, 324a-d

See also separate provinces.
Notch Peak, House Range, Utah, localities on and near.--.--...- 30m,

30w, 30y, 31q, 105t
Notch Peak limestone (Upper Cambrian), in detailed section in
House Range, Utah, listing included and correlated spe-

Ciesiandulocalitieseeme sees eee ee tecee ee ie eee 153

loonie Th, o-oo s aston stest bese neseeodspeescoates 30m, 30w, 31q

notchensis, see Obolus ( Westonia).

Nounan limestone (Middle Cambrian), in detailed section in
Blacksmith Fork, Utah, listing included and correlated

species and localities ..........--------------------------- 149
Oey NS soos sooo saeoaces soa aS soe oen ened eSase ssepssas=5 56f
Nova Scotia, localities in. ....-. 8h, 3i, 3n—q, 8d, 10c-t, 11z, 13d-i, 13k-r,

13t, 13t’’, 160, 307, 307a-j, 325, 325a-c, 344, 344a-0, 372, 372a-f
See also Cape Breton.

CAMBRIAN BRACHIOPODA.

Novgorod, Russia, localities In..........---------00----0----- 336], 336s
nox, see Acrotreta.
nundina, see Obolus and Syntrophia.

Nuneaton, England, locality at.....-..-....-.----.-------------- 3040
Nunkoweap Valley, Arizona, localities in.............-..------- 74, 74b
Nuns Hill, near St. David’s, South Wales, locality at...-.-...--- 366¢
Nye County, Nevada, localities in....--....------.------------ 74, 313g

nympha, see Eoorthis desmopleura.
nyssa, see Micromitra (Iphidelia).

Obolacea, classification of-..-.......-....--..--------.--------- 321, 322
distribution in Cambrian strata.....-.-.------------------- 316
genera and species referred to described

Obolelox described eerste eee eee eee een

articulating processes discussed
cardinal area discussed
Classificationio fees asses ee eee see eee
compared with A crotreta argenta -

Acrotreta emmonsi....---.----------------------

IEG he osc adoscse ease see co2S coat cHUsessnIeDIGOCn
Botsfordia..-. sen (HOY
Dicellomus. .- - 572,577,592
Elkania..--.--- ---- 562
Elkania desiderata..-..-.-.--------------------- 562
LQU UUM scns cases sees os os en aeezscessccese0S
Lingulella..- .
TiN GUlella Prva = orm =m = mm = ole ei 527
CERTUTLOMS SO TRE LL ete te eee 314
Obolella (Glyptias) favosa 600
Obolus-..---- - 312,376,592
Pentamerus.. 597
(MMA scoanecocesaqcsceococces peas os oSSenes= 611 -
Tn em (LOO US ee eee eae 615, 616
Trematobolus kempanum...----.-------+------- 620
Yorkia ? washingtonensis ........--------------- 612
development mentioned....-......--..-----.--------- 562
evolution discussed 319
QOMWIMOVN Oia. = oa ces sce ssosssossasassesassussessasces 317
general geographic and stratigraphic distribution of

the species referred to...----.------------------- =.= 104
general stratigraphic distribution and number of

Cambrian species and varieties of...........-...-.. 110
Hall and Clarke on development of..........-..-...- 309
mentioned. .....-.- 373, 386, 388, 389, 392, 403, 423, 471, 472, 650
muscle scars discussed.......-----.------------------ 312
number of species of, in the different types of sedi-

MONG sacs cee pees eee eee ee eeeeee eee 160
pedicle tube discussed..-------------.---.-...- 314
reference of Obolella asiatica to, discussed .- - 589
She LUSGRUCTUG mere seen ee eee eer 297
stratigraphic position mentioned....-.....-.....-.... 318
surface ornamentation discussed 302
vascular markings discussed.-...-.---- E 311

asiatica, described 588
general geographic and stratigraphic distribution tabu-

IENGio le sen oeadccneteosocesatesssscc ERE e et Stace. 104

type specimen figured.....--..---.--
atlantica, described....-.-------------------
compared with Acrothele bellula--.-..- :
Lingulella acutangula.......-------------------
TATUM SS OME ow w= alm = = = minim = eae eel
Linnarssonella tennesseensis. .

Obolella chromatica.

Pl. LY, fig. 6
. 589

Obolella crassd.....---------- &
Obolella minor... 2-2 0~------------5---- ~~ == =~
Obolella mobergi-.--------.-.---+---------0-=---
Obolus ? zoppi
GIRCWEREG! Hs ss cceoenenrcesesoe seecece
general geographic and stratigraphic distribution
(HIRANO sects eadsoessancesconeoossgecseszeet os 104
type specimen figured. .-_.-.---.-------.-.- Pl. LV, fig. 1h
chromatica, described. .-.-..----------+---.---0-----------== 591
compared with Dicellomus politus.....---------++----- 572
auitorgin@-n-2 2-28 a 579
Obolella atlantica..--. 590
Obolella crassa -...-.- Boos
Obolella moberg? - - 598
QINeDECLONCTIC Cee sane eee eee eet 610
general geographic and stratigraphic distribution
tabulated.......- BERS E DU SECSISBOSACCOUOCOSRE ROU LOO 104

type specimen not figured.

:

INDEX.

Obolella cf. chromatica von Toll, discussed .......-.-.-.----------- 592
EN CUIGES MU yIIDe ON QUEUE CU ae ey alam same ae aia alee ele 610
PNIETIGIONEG Ceyecrerce cae cts Sam woe ree eens se eee eee 610, 611
CTROSSOCeSCrID EC cee nee asa eee 592
compared with A crothele bellula. 637
UBicia ese sche: sep eee 568
Botsfordia . 602
(QUANG CSTOPON 5 ssstacscsscoensso22e coe 22550 589
591
Obolella crassa elongata ........----------------- 595
(Obolelianmnobergiee ses eee ee eee 597, 598
Obolella vermilionensis -..-- 598
Obolella wirrialpensis .....- 599
Obolus ? zoppi....--------- 422
discussed 587
general geographic and stratigraphic distribution
(POW EWEG 5 sscgssaassoes5c sage soe bocosecossseazcon 104
shell section figured.........-.-..-.-------- text fig. 14, 299
type specimen not figured.
crassa elongata, described.........-.------------------------ 595
compared with Obolella groomi.. . 596
general geographic and stratigraphic distribution
tabulated ....... pogcaseonaeedacqacssanccanconeccess 104
type specimen figured.. . Pl. LV, fig. 5
“gemma,” type of Bicia.--.-. 569
groomi, described 595
general geographic and stratigraphic distribution
(EI DUENIC! «5 onsceac cacao sesdSsosscocacasteesconssuses 104
type specimen figured .........--..-.------- text fig. 52,596
CTD? CHSCURSEO «3 oc posoonnsssscocasoscoseadssosascoestoc] 563
PilimdstrOmi, Gescribede.- = 2. e = «= 2a es mn eee 596
compared with Obolella chromatica....-.-- 5 591
general geographic and stratigraphic distribution
(DINING - = doce coconeesdoesemaneeosaoacoeceeansce 104
type specimen figured...........- . Pl. LY, fig. 4
“maculata Delgado,” discussed 599, 660
HLT CESOM TO | 6 = ae capa bos 28S coooaeonosassoneecsscneasaS 596,
general geographic and stratigraphic distribution
THELTMIAGL . s oocaesccnnooenaceennaccosesaocsasencac00 104
type specimen figured..................-.. Pl. LIV, fig. 3a
TNA Pr, CONGR ONOL, - oo 35 soe eps ogd sede oS coe soSescorasso5 597
compared with Obolella crassa.......-..--.----------- 594
Obolella? lindstr6mi ......--.------------------- 596
general geographic and stratigraphic distribution
(DISTHIETICG! « -noadeossoossoenadsboceesosocosesosesoDES 104
type specimen figured.........--.......----- Pl. LV, fig. 3¢
“nitida,”’ discussed 527
plumbea, compared with Obolus? bavaricus..-.------------- 386
KC pT eviOSW,22) GASCUSSC Wine === =e ae = eee = 705
COSC MTIICeN ACLS GUSS CU ae eae ete ee ee 703
“ salteri,” type of Obolus (Bréggeria)......-.-------------- 377, 424
vermilionensis, described 598
general geographic and stratigraphic distribution
tabulated ......-.-.-- 104
type specimen figured. - text fig. 53A,598
wirrialpensis, described 599
general geographic and stratigraphic distribution
(OWA coscmabesoaosossscoodenosHcosecconncens 104
type specimen figured Pl. LV, fig. 7b
wirrialpensis calceoloides, discussed ........-.----.---.----- 599
“sp. Bornemann,” generic and specific reference discussed.. 403
SHO WiNGhic,, CISA IG) - coo -ops- costosseneaesonsosaseseancse 599
general geographic and stratigraphic distribution
WPINMNBEL- ooccessosnasoseeosscossoassaveosco0gn|os 104
type specimen not figured.

Obolella ( Glyptias), described 599
classification of. .......- 321,324
compared with Obolella...........-..---.--.--....-.- 587
CVOMUIOE Oia ees cage tees scaeas eo ssdoscoesederossocs 317
general geographic and stratigraphic distribution of

iihe|speciesineferredsto meena eee eee e eae 104
general stratigraphic distribution and number of Cam-
brian species and varieties of.......-..-..-.---.---- 110
number of species of, in different types of sediment... 160
surface ornamentation discussed 301
type species Lingula ? favosa...- - 099
TPRORT, CEVSM NRE... <5 sonesos sede tos scot cose sees oesaccasade 600
compared with Obolella mobergi..-------------------- 597
general geographic and stratigraphic distribution
tabulated eeeeesa een tees ce eee easel 104

type specimen not figured.

“ Obolella (Lingulella) prima,” discussed 527
Obolellide, classification of
distribution in Cambrian strata. -

genera and species referred to, described..-...-..-------- 586-611
general stratigraphic distribution and number of Cambrian
genera and species of.-.....2.-.-.-------------- Pee iL 2
number of Cambrian genera and species of. 5 112
number of genera and species in monograph....------------ 113
Oboli, evolution of, according to Matthew, discussed. -...---..-- 319
Obolide, classification of ....-....--.-..------------- - 321,322
distribution in Cambrian strata .- 315,316
genera and species referred to, described -.- 370-578

general stratigraphic distribution and number of Cambrian
(avatars) AVG! BPO Oe 9 oo5cacssasccoocoococeaseasscaomace 112
number of Cambrian genera and species of. - .
number of genera and species in monograph. .
number of Ordovician genera and species included in mono-

301
Opolinesclassificahiontofessseeae eee eee eee eee eee eee ears 321, 322
genera and species referred to, described .........-.------- 370-561
Obolussdescribed == ss = see pees ee=e eee tees aera 370
cardinal area discussed -.-..-...-.-....----.---------- 304
Classification(oPeress-ae rece seee eee ee ence 310, 321, 323
compared with Acrothele.........---.-.------------ 631, 632
PAICTOLVYT Cane eee eee ee ee 716
LAGOME soa saoccosgdo scons as 2oosasdosscsreosses 673
A crotreta argenta....-.- 673, 674
PBicia sa penne nee ene eee areas see ee ase 569, 570
DHIHIB GUM ran cacocsscesccescse520e9s0ces05205 570
IROOM assoces cna sascsGesoounReocossoy=oeeeEN 601
IRYG OHH GAD ooo moa ooc coon scae2ascco75se03es0 604
Botsfordia granulata......-.-.------------------ 606
CUntiCIO AI en Poe eee eee ee ese 318, 369, 370
DFM ROTT > soca sanconc cos 20esaor 296 SonbeSceoS 614
DViCellONVUS eases Hae eee ee ee eee 312, 572
TOY SOs eon cco= 561, 562, 563
Elkania and Obolus (Fordinia)....--.-.-------- 428
TURD CSUR ocwocncossconssccs2a0nsesccsso 563
“ Buobolus”’
Helmersenia
Keyserlingia buchi.........---------------------
SALON GUNG eee eee seine a teenies eee
“< Takhmina linguloides”’ - -
LGR Mio 2 s0e2c00Ree
STG ULELL Oe
Lingulella by Matthew.-.-.-.-------------------
Lingulella acutangula..........--.------------

Lingulella prima... --
Lingulella radula....--.-

Lingulella (Leptembolon) - é
Lingulella (Lingulepis).......----------------

Lingulella (Lingulepis) acuminata..-..-.-.----- 547
Lingulella (Lingulepis) exigua 553
NOT SSOTLCLL eee eee eee een eee ee 312
TNMATSSONELUG, Girt te o= ees = = = 666
Linnarssonella tennesseensis...-.-..------------ 670
BO POWs aaaccs zeson cs co2 2soozcaebnagesde 378, 410
INANIOBS cdo pecemodosooupedessu5one . 564, 565
Neobolus warthi.........-.---------- -- 566, 567
INOSUISED HAMIL Reise os ocestuosecoteseseceoseesso 728
Oboleta ate nese eiel-e leer 312, 376, 587, 588, 592
QUIS (CERAYTTHOD) cocoodbossscosece=seaeacesbe 424
Obolus ( Fordinia) bellulus.......------------- 498, 429
Obolus ( Fordinia) perfectus.....-.-------------- 430
Obolus (Lingulobolus) ..-...--- .-- 480, 431, 433, 434
Obolus (Lingulobolus) spissus.....----------- 433, 434
Obolus ( Westonia) escasoni...------- -- 460
Rustella? major by Matthew. ------- Se)
Siphonotreta unguiculata......---- =5 CR
ER ETALOUOLUS Re eietciae ee na eee eee eee 313,616
Trematobolus insignis....-.--------------------- 618
Trematobolus kempanum “ 620
Trematobolus pristinus..--.--------- == Cl
criteria of subgenera. . - 376
development of...... 309
evolution discussed - - eo BS
GNOMBTGM Oe 5 oan ecos ends sse0 sens oosaosasSoonospeen 317

852

Obolus—Continued.

general geographic and stratigraphic distribution of

the/speciesireferredt0b= eee = eee eee 99, 100
general stratigraphic distribution and number of Cam-

brian species and varieties of. ...-- Been) LO
geographic distribution discussed - - . . 379-380
Hall and Clarke on development of.....--..-...--.-- 309
largest and most recent species of...--...-.-.---.---- 392
latest American species of. .......-.--.--.------------ 386

mentioned. 310, 381, 386, 387, 388, 389, 392, 403, 405, 407, 408,
409, 411, 413, 414, 422, 423, 428, 435, 436, 439, 441, 442, 463, 470,
471, 472, 473, 474, 475, 478, 489, 503, 505, 527, 531, 532, 541, 590

muscle scars compared with those of Neotremata... 312,313

muscle scars discussed .........------+----+-----+----- 312
number of Ordovician species and varieties of...--- ee Allg}
number of species of, in different types of sediment.. 160
pediclosturrowsdiseussedsy cr se- ees see eee eee 314
reference to, of Acrotreta ? minima, discussed..-.-.-.-- 695
relative position of yascular sinus in species of..-.-.-. 376
shell structure of compared with that of Lingula.....- 296
species and varieties recognized by Mickwitz listed... 380

stratigraphic range discussed
subgenera characterized -....--

378-379

subgenericicriterias 2!) se se ee tos eee eee aesee eee 376
surface ornamentation discussed.................----- 302
THYIOE) SOGIONEN GhISCHREECL. = = 5 sss Ses co sscesesonssessed 373
type species Obolus apollinis ......-..-.-------------- 373
umbonal muscle mentioned............-.----.------- 313
vascular markings discussed......-...--.---------+--- 311
‘acadicus described iets esses tee te eae ok ee Saiceee ee eens 380
confused with Lingulella concinna.....-.--.---------- 380
general geographic and stratigraphic distribution tab-
(late detec a ce ese ecm mashes eee aia eploemciniae=
type specimen figured

eadvepats described ers. = ansce as soe ales eiscemee tease
general geographic and stratigraphic distribution tab-
sTUL AGO ibe cee esters nel inicisre nares sitet ric tetercls)<ient ote nie sisters 99

type specimenfirured!---2--25--2-------.---- Pl. XII, fig. 5
xquiputeis, identical with Obolus selwyni......-------.----- 414
Gnceps: described ease sense = cee eniee ace seis ovens sine cena" 380

compared with Obolus nundina.......-.-.----------- 406

QUDIIS Ads WGN Cees seca ss4eeesssomoupeeaseo 423,
general geographic and stratigraphic distribution tab-
late dese eee essen a eters sins sem eon linn tec 99
type specimen figured.........-......-...---. Pl. X, fig. 3b
PONS) CeSCrab ed seems ae eae aeciree oe eine 381
compared with Obolus ? mirandus........-.----------- 405
general geographic and stratigraphic distribution tab-
lated eee ieee ae sectee ok scene ree emioecicsinnine 99

type specimen figured..........---..-..--.-- Pl. XII, fig. 2
apollinisNGesc np ed ements a see e ene eee era ee een otal

cardinal area discussed. ..- S 304

comparediwitheB7c7d seme senee eee ane eee cern ee ce 568

PELE ONLI ON LESTE? O10 meee eae eee 562
Lingulella acutangula..........----------- 472, 474, 475
Linnarssonella minuta. 668
Neobolus warthi-.... -- 564
(Obovellaxtchromai cree eae eee ee 592
(Oboleliaicrassae meee senses een cease eee ae 594
Obolus apollinis ingricus . 384
Obolus apollinis quenstedti . 385
Obolus feistmanteli...-. 391
OWUIS SA. soos esa seenbocoebooucoooeceres 379
Obolus (Fordinia) bellulus.......----.-.-------- 562
Obolus (Lingulobolus).....-.------------- eee 43
Obolus (W estonia) escasoni........-------- 460, 472
Siphonotreta unguiculata........-..-..---------- 625
general geographic and stratigraphic distribution tab-
uilarte deepen ee re esr tais sep ta iet mises steerer

interior features discussed -
MOTSCle}|sCans ISCUSSC Cesar es eee lena eee

old-age characters discussed. .........-.-.--.--------- 315
PlatiormiGiscuss cesses eases eae eee ee eee 310
shell sections figured. ..-......-- text figs. 4, 15, and 15a, 299
thickening of shell beneath visceral area discussed.. 309-310
tubules of, discussed) =~ == =e - ee ee 300
CITI OROWNMS = 5200 ssocnssessaodadsesredteososaesses 373

type specimen not figured.
vascular markings discussed....-...-.-.-------------- 311

CAMBRIAN BRACHIOPODA.

! Obolus apollinis ingricus, described .........-....-.-.---.---------
compared with Obolus apollinis maximus .........-.--
Obolus apollinis quenstedti..........--....-------

general geographic and stratigraphic distribution tab-
ulated... -

type specimen not figured.

apollinis maximus, described... <2 2-25-----2e-2-eeeseees sense
compared with Obolus apollinis quenstedti........--..
general geographic and stratigraphic distribution tab-

type specimen not figured.
apollinis quenstedti, described........-.--.---..-------------
compared with Obolus matinalis........-..-..--------
Obolus mickwitzi.....---.-
Obolus selwyni -..-
Obolus (Mickwitzella) siluricus-

general geographic and stratigraphic distribution tab-
ulated
type’specimen figured). -2-- 52 ---2--------

AULD HES OETOM EC atiesc ondsmoccosedsowsdsedoadoseeosesen
compared with Lingulella wirthi.
general geographic and stratigraphic distribution tab-

type specimen figured .
chinensis, described
compared with Obolus obscurus.......--------------
Obolus prindlei........------

general geographic and stratigraphic distribution tab-

type specimen figured..............----
complexus, described.......-.--.--------- tices a catenins e ees
compared with Obolus ? advenus
Obolus ? rokitzanensis . .. Bae
general geographic and stratigraphic distribution tab-

(IEC Restae deSeBcoScacosteroneacsonGaesecaedaasccs 100
type specimen figured.............-.-.------ Pl. XII, fig. 3
cyane, described 388
compared with Lingulella iole..........-.------------ 508
Obolus ( Westonia) rogersi........--------------- 464
general geographic and stratigraphic distribution tab- E:
wWlateds ces te oe yaaa cerelecis =r a eae 100
stratigraphic position of, discussed .........-...------ 389
thickening of the shell beneath the visceral area dis-
CUSSOG) 5. hoc sis nosecice ssa ainc eens sce ee sane 310
type specimen figured... ..-- . Pl. XXVII, fig. 4
damesi, change in generic reference. 489
discoideus, described......-....------ 389
compared with Obolus worthent........-..-.---------- 421
general geographic and stratigraphic distribution tab-
DIGI EaaeasceaacsaconcobnobaccneanScasoRoncackess 100
type specimen figured . .-- Pl. XVIII, fig. 6¢
dolatus, Aescribeds: 3558 o99 san asso heocte see eae oO
general geographic and stratigraphic distribution tab-
(EUR ee tee ho eR nS coeecinasecedorgtoseniosénace 100
type specimen figured . text fig. 35A, 390
Cy DL, OE SOmMoNOlS oo e a origsocmmsosasoocsonesaesendsescodr 390
compared with Obolus volborthi.....-..-.------------- 419
general geographic and stratigraphic distribution tab-
ulated 100
type specimen not figured.
Alyy, les oai a6... seo spe occas scoot oenecazecsossssere¢ 390
general geographic and stratigraphic distribution tab-
WPIAC EN pops sess asnanscecke dadaccoscapnetadoanvedc 100
type specimen not figured.
erst Montel GC CSCRIDEO eee sae ee eee eee 391
compared with Obolus complexus......--------------- 388
Ovolus membranaceus......-.-.----------------- 402
Obolus ? mirandus 405
general geographic and stratigraphic distribution tab-
LAE: (6 eR fey ho ae ae St SEM SRE Shia ERceE oes 100
type specimen figured... . . Pl. XII, fig. 1d
PREG, COTOM IG. 4s 5s2d cos ooonsessbop sso seusesaostous 392
compared with Lingulella bellula....-.--------- -- 482
(QHOUNS HWY ace seco cmecaneces sdoocnossteess 410

99

384
401
404

414

435
374

Wlated ees a soeee espe eens are eee ee ere ee ee 100

type specimenifigured_-..-- 222-5. --2 2-2... Pl. XV, fig. 10

Bellz, described on coca Somes sce ers ateeet meee eee eeeree 386
general geographic and stratigraphic distribution tab-

MIE cos csneeces 100

387

—

INDEX.

Obolus frajivis—Continued.

‘general geographic and stratigraphic distribution tab-

NU SG Dae e ae see one ats Sete apne wees Me leeer eee erate 100
type specimen figured...............--.-- Pl. XXIII, fig. 5
MAUD; ICTS RO CSCOLDE Cee ert = eae ole ee 393
general geographic and stratigraphic distribution tab-
THB G oases eeeeaet eee eeseesepecocsssedoces cosen) 200
type specimen not figured.

SEP TICUS en O0 CLIULOL Ceres ee eee eee eee ee eat 383
ismene, described 393
general geographic and stratigraphic distribution tab-

Ua tec ocean ae 35 cae th pe Nar eal rea 100
type specimen figured.............-.-.-.---.-
Cine.” WONG. = 555 seannoc coder neo seussesos=0

notes on generic reference of
not the type of Beecher’s genus ‘ Paterina”’ ....------
lamborni, described)... ..--..-------------------------2-"--- 393

compared with Lingulella hayesi.. 505
Obolus lamborni minimus . . 395
Obolus smithi.........------ 417
OWES DUES oo sbocsososoaotcodaneeccogdozo8oDe8 420
OARS HARB .c scons scan seonosooezQnsccoDeneeZSo0 421
Obolus ( Westonia) rogerst 464

general geographic and stratigraphic distribution tabu-

TenigGle bes scesesaccsoesenescaseuanSasnouosdosEcuoses 100

type specimen figured ..........--.------- Pl. XXII, fig. 2j

lamborni minimus, described ....-.------------------------- 395
general geographic and stratigraphic distribution tabu-

TEINS A= See es aoe to ana ee Sparc maEsanemoeBoonSODaaG 100

“lens primus” discussed 428

LO eTbtC CSCHIDCG earner ete ae ae a etal eta 395

compared with Obolus ( Westonia) themis...-.-------- 466
general geographic and stratigraphic distribution tabu-

Tce sactboouancedoneteccounaaSecamaspsdeoonocacoaas 100

type specimen figured.-..-.-- . Pl. IX, fig. 4a

meconmelli, described....-.---.-.---------------------------- 396
compared with Lingulella helena...----.------------- 506
Obolus mcconnelli decipiens ..-..--.------------- 398
Obolus meconnelli pelias .......----------------- 398

general geographic and stratigraphic distribution tabu-
100
stratigraphic and geographic distribution discussed... 397
type specimen figured.............------- Pl. XXII, fig. 3
varieties discussed ........----.-..-.----------------- 397
meconnelli decipiens, described ...---.---------------------- 398
compared with Obolus meconmelli.......-..--.-------- 397
Obolus meconnelli pelias.....-..---------------- 398

general geographic and stratigraphic distribution tabu-
IMIG oocéudaccoLocosessaupeesenooopccadcoossousades 100
type specimen figured -. .. Pl. XXIII, fig. 4
meconnelli pelias, described......-.----.-------------------- 398,
compared with Obolus meconnelli.......--.----------- 397
Obolus mceconnelli decipiens ......-.------------- 398

general geographic and stratigraphic distribution tabu-
TEI coggouabududasdaousoss sacunseacsoonsaoeuogedS 100
type specimen figured....-...-.....--..- Pl. XXIII, fig. 3b
TEAC, COSCO. — oe secansos scosctooonooaseonocos sedenecesas 399
compared with Obolus anceps .....-----.------------- 381
OWINS TLV conso6qs20cebg0 2 stoesae220082 401
Obolus mickwitz . . . 404
Obolus sp. undt. d 423,

general geographicand stratigraphic distribution tabu-
IEWIRCl aa ndgscuosocusaquennesossndeunoseUncoapsopapaD 100
type specimen figured .. Pl. X, fig. 2a
matinalis, described. ......-.---.-.-- 400
compared with Dingulella hayesi.....-.-.-.----------- 505
EEA GULLeLU GD GOT = 2 ea ee ee oem eae a ein 525
Lingulella prima... ..-- 527
Obolella (Glyptias) favosa. 600
Obolus anceps... ----- 381
Obolus dolatus 390
Obolus feistmantelt ...-.-----.-.+.--.--..-.... 391, 392
OVWMWMS UN NG acocas=cossootsseoscemon=ce - 395, 396
QOS TEMG mekoussosecsssostencasenossee - 399
ODO SVINiCKADiL Zi een ee ee eee - 404
Obolus namouna ......---.--..-.-2------------= 406
Onolits panienviaia eee eee eee 407
UDI GUS SSB ca ROSE Se Cron eae Oe ce EReeod 410, 411

Obolus *nutinalis—Continued.

compared with Obolus shansiensis 415°
Obolus tetonensis ....------ 417
Obolus tetonensis ninus . 418
OLYMS So, WAGs O Soe acHencs sooo sromescosceens= 423
Obolus sp. undt. f 423
Obolus (Lingulobolus) affinis.....--------------- 431
general geographic and stratigraphic distribution tabu-
lated et eae eene ace e Meee aera eee seetaiatyertal 100
type specimen not figured.
matinalis?, described........---.--------------------------- 1402
general geographic and stratigraphic distribution tabu-
Labeda see ace et oan et a deface ame atererare (seashell 100
no type specimen chosen.
membranaceus, described....-....-------------------------- 402
general geographic and stratigraphic distribution tabu-
EVR o Ea ee) Sa a eSaR MS cget odaadebaSnaesEaecad 100
type specimen figured .......-.....-.----- text fig. 36A, 403

? meneghiniz, described. ... 403
general geographic and stratigraphic distribution tabu-
[Biel caneconscadesrescncos ssenonoEagscoccesescasees 100
type specimen figured........-.-----.----- Pl. XXX, fig. 17
mickwitzi, described 403,
compared with Obolus refulgens 410
general geographic and stratigraphic distribution tab
la teds eeee cee sameness cocice sees noema cee e sins o eens 100
old-age characters discussed. -.-.......-.---.--------- 315
thickening of shell beneath visceral area discussed..-. 309
type specimen figured

minimus, described
general geographic and stratigraphic distribution tabu-

NB LCC eae eect sae ctei skis nue oe eee 100
type specimen figured . Pl. XI, fig. 8
? minor, described 405
general geographic and stratigraphic distribution
tabulatedets se msec eeece oacee cen eeetence ater 100
itypelspecimentipuredseseteesaceeeereereeeoe Pl. XV, fig. 6
FTES, DESOM OTC oo cecanno-sosnusbecosocsnessceoesccs 405
general geographic and stratigraphic distribution
(STH et Camp anmanbasceaoaneccadereetercsenoesa 100
typelspecimen) figured()><2-- 22-222... ----- Pl. XII, fig. 4
f? MPU, CECA OC - co osccossscnodenoesescoconeeosuaconce 405
compared with Lingulella lens...........-.---------- 513
general geographic and stratigraphic distribution
el a Le Mee aeyateyaaraiciatae pretehiorae se we eect acim cree 100
type specimen figured...................... Pl. XV, fig. 12
HOMONU,; COSC N05 ssa SogcccoeScenseascoobouseSeeeeseeeone 406
general geographic and stratigraphic distribution
tabulated ier asa sne ys cle ees meccen ein eetseacesa 100
hype Specimen A SUTeC sees eee ee eee ees Pl. VIII, fig. 2
ERAT, CES NN = A555 c5cccsdscbbasoccoonoscecesoeuodes 406,
compared with Obolus obscurus.........--.---------- 407
general geographic and stratigraphic distribution
tabulated’ je ssaaenle estas seis ee cae ae Meio 100°
type specimen figured...---.................- Pl. XI, fig. 4
CUSeMTTS, Clesullyetel 5-550 s5048soddccad acosascqcosdeaandesseoe 406.
general geographic and stratigraphic distribution
tabullatedaestemsecnrnsctec nace ee eeiae ane cence 100!
type'specimen figured. <--.2..222.-2-.-.--.--- Pl. XI, fig. 9:
? palliatus, described... .-.-- =. 222 jens secre ee eee en eee ene 407
compared with Obolus? minor ..............-.------- 405
general geographic and stratigraphic distribution
LENIENT eee haar os mancumsTandetae seu sceaEaSeetee 100
type specimen figured.....-....-...-........ Pl. XV, fig. 5
pondemio Gescnbed wees see eee aeee cece eee eee eee ee 407
general geographic and stratigraphic distribution
tabulated es--see=== 100
type specimen figured. . Pl. IX, fig. 3a
panderi, described 408
compared with Obolus triangularis...........-------- 419
general geographic and stratigraphic distribution
abulatede emer tse. eter aren eins hee eee 100
type specimen not figured.
OT UUS SACS EC ep wem eee eee oe ea me eee ae e 408
general geographic and stratigraphic distribution
Labulatedemeracesassan tcc e ose tee eee ee ere 100
type specimen figured ... --. text fig. 37A, 408
pheres described seperti es on ae ease ane ee e eee eae 408
compared with Obolus parvus....-.....-.....-------- 408,

854

Obolus pheres—Continued.
general geographic and stratigraphic distribution tab-

(WENO 56 Soo sccaossosossccuereesese soressoccsosces 100
type specimen figured............--..----+--- Pl, XI, fig. 6
OTUOLEYACeSCLIDE Clana a eee ee eee eee ee eee 409
cardinal area discussed ......-..- 303
compared with Lingulella davisi... 379
Obolustapoliiniseesese renee eee eee eee eee 379
Oboiusichivensisseyee eee eee Ree eee eee 387
Obolus:topert!t/ 352 Aho ote eee eee eee 396
Obolus (Lingulobolus) spissus- - 433
confused with Lingulella granvillensis.........-------- 409
general geographic and stratigraphic distribution
tabulated so ire eee eens ee eee eerie 100
type specimen figured. Pl. XXVIL, fig. 3

pulcher, type of Botsfordia.........-.-- 601
“quenstedti,”’ not the type of Obolus .......----------------- 373
refulgens, describedsah. o> sca eeee cee ea eee eee. 409
general geographic and stratigraphic distribution
tabulated). ...---------
type specimen figured... -
rhea: described nr eee cane gecacieae ce cee ee mtiaeeeea ee 410
cCardinaltarealGiscussedieeeesse eee aeeeeeeeeaeeeeceeee- 304
sfompared with Lingulella schucherti.......----------- 530
ONQUS CUCM = B56 Soceooseccosentececscecoasee 407
general geographic and stratigraphic distribution
tabulated aseesema thee eee tee cae aee aaa eer a, 100
type specimen figured .......-.....----------- Pl. IX, fig. 1
PATOK ZO NETISIS NG CSCHIDE Cee ease eee a eee eee ee eet 411
general geographic and stratigraphic distribution
tabulatede ee sce esebtece soes ce oce sees eesae seen 100
type specimen figured_..--..----------------
Tolundatus, | escribedees = 2 s5-) === = === ==
compared with Obolus parvus -
Qbolusimnindlcipeeeaneeene eee eee
OUOISISCINLALENS Cette neta n eee eee
Obolus septalis
OUDIUSISUN OC eee eee eee
general geographic and stratigraphic distribution
tabulated eee cctse cok went voces tee eee ese 100
type specimen figured............-.,.-....-- Pl. XX, fig. 2
SCIUMALENS CCl CES CHING User ae eee eee eae eee eee 412
general geographic and stratigraphic distribution
THE OWUB UOC! S 6 saccicabcibaes sscemoodaASocansepsssoceesee 100
type specimen figured..............-..-- Pl. XXX, fig. 19d
ISCHNMIGH CL OSCLI DE Om teteeiemiets =e ieee eee eisai eee 412
general geographic and stratigraphic distribution
habulatedaeecea. eee eseer ewes eee ee eee rea 100
type specimen figured. . Pl. XV, fig. L1a-
SANG; CESGI ING. 53505 eon sseeoscoossonecoseceseces 413

compared with Lingulella irene.....-.----------------
Lingulella (Lingulepis) roberti -

discussed eseeeeee rer eee eee eee eeeer ener ame
general geographic and stratigraphic distribution
Lap ulated sees eee eee cee eae ate a 100
no type specimen chosen.
stratigraphic position of, discussed -.....--.---------- 414
aaoiby, Careless oon sos ssosbcénotsoccassacenssedeses 414
general geographic and stratigraphic distribution
LDH 5 45-5 osessed saossseo To esescesousdconcs 100
type specimen figured ........-...-.- Pl. XXXIV, fig. 2a
shansiensis, described 415
compared with Obolus minimus......--.------------- 404
general geographic and stratigraphic distribution
bali ate daracacce centre secre sare cmiciae selector 100
type specimen figured...........-..-.-.---- Pl. XI, fig. 7a
“ siluricus,” mentioned.....-.----- 531
type of Obolus (Mickwitzella)........--.-.---------- 378, 434
SPOR, CeO Neo. Ace goades soseneen coe sos onsesecoce so5e> 415
compared with Lingulella (Lingulepis) acwminata..-.- 545
general geographic and stratigraphic distribution
tap Ul ate desea enmeree ee stecia aos essen 100
type specimen figured -......-...-... Pl. XXSVE, fig. 2f
STALL ACESCHI DG Cie teen eee rata oe eine alco insta rat 416
confused with Micromitra (Paterina) major..-.-.------ 351
general geographic and stratigraphic distribution
tabulate dityee se esac ee sees ans an orate 100
type specimen figured.......-..-.-.------ text fig. 38B, 416
ELONENTS?SOCSCUI De d seen eee pet Ree eee ese aete a 417

compared with Obolus shansiensis....-...------------- 415

CAMBRIAN BRACHIOPODA.

Obolus tetonensis—Continued.

compared with Obolus tetonensis leda......-..-..-. 417, 418
Obolus tetonensis ninus .....---- - 418
Obolus wortheni eee, 42
general geographic and stratigraphic distribution
tabulated hae Soe oo Saaee ae eee eee ene 100
type specimen figured
tetonensis leda, described -.-......-.---.-.-----
general geographic and stratigraphic distribution
tabulated .222-s2bsech estes Se See eee ose eee 100
type specimen not figured.
tetonensis ninus, described. 418
general geographic and stratigraphic distribution
tabulated ss 95.\5- Sse Soe eee een ane ners 100
partly made up of specimens first referred to Obolus
MANAUS S/o. fos Seledee sobs chose coeaae s csee sec aes
type specimen figured.
Pitornentis, described. - 22 25--22-2e2-=---ee one
general geographic and stratigraphic distribution
tabulated cs sees cotete ce eeoece sees cece 100
type specimen not figured. ;
QCM i, COM El. os sms Sade egeognassaonccassbosscoss 419
compared with Obolus cichwaldi. 390
Obolus!pandenis ssc ent Noe noes cee ee eee 408
Obolus ( Mickwitzella) siluricus...........-.-.--- 435
general geographic and stratigraphic distribution tabu-
100
type specimen not figured.
triangularis inornatus, identical with species..........-.-..- 419
Volborihi\ described eeset es eae eee eee ae eee eee eee 419
general geographic and stratigraphic distribution tabu-
lated oo. oi neces See cones 100
type specimen not figured.
willist; desenlbedie-2-sectee eee see eee Hare eee nee eee eee 420
compared with Lingulella hayesi.......-.-.-.-.-...--- 505
ingulellagspeunditi beeeee ee eee eee eee eee eee 541
Lingulella (Lingulepis) exigua.....-.-..------.- 553
Obouswmvonnieese eta epee eee eee eeeeee 394
Obolusismithizees -2sseeeeene eee eee eee eee 417
confused with Obolws lamborni.......-.-..-----.------ 420
general geographic and stratigraphic distribution tabu-
lated 2s ga 2582 cote tena Gene hemes BAH anetau sacs 100
type specimen figured. ........-.....-.... Pl. XXIII, fig. 1
Worthent GeScribed sees = eee eee eee eee eee ee eas 421
confused with Obolus tetonensis .........------------- 421
general geographic and stratigraphic distribution tabu-
LEA ite FR eee eee Paar me dee tie dasenpSEeae aioe 100
type specimen figured..-........----.------- Pl. IX, fig. 5e
getus, describeduc; s22-c Secs sete nee oe See eee eee oak eee 421
general geographic and stratigraphic distribution tabu-
dated). 2< 2 tefssce tees bee esh a eet eee ee eee 100
type specimen figured . ..-. Pl. XXV, fig. 3a
Warn CCG Hl olen aceon sssasoseoocesasoacasSorhomsscoss: 422
general geographic and stratigraphic distribution tabu-
lated )sa. Sess eos Se oe esters aeeeeette ser ee tae 100
type specimen figured.........-......-..- Pl. XXX, fig. 16
sp. mentioned. 367
Choy, LG Sabubi. oliobNeGl. - .5o5- ssn costes oncesosodsenasssa0e56 598
Syo}s Patol. Gin Polo gee eo Sones sdoisuasousssc0nse 422
general geographic and stratigraphic distribution tabu-
Tated ns - eeee eee see

type specimen figured...
sp. undt. b, described
general geographic and stratigraphic distribution tabu-

lated ne see eee ecice ch cease eerie eeetrecerete sate 100
type specimen not figured.
Riel buNGhis CRASH 20 |. ce Sosseoessasesss sees esecatiassaes 423
general geographic and stratigraphic distribution tabu-
JEG Wane coe Oscesetcmeaaccde ba seccpooccosgcscaSct 100
type specimen not figured.
Sho, Husa. Gh Gomes 8 oo sos seezcsooaceossezenece se 282 423
general geographic and stratigraphic distribution tabu-
IPVICG los see se cose sotcoa soso osoccsonsancoassorsesesso 100
type specimen not figured.
sp. undt. e, described ...---..-----.------------------------ 423,
general geographic and stratigraphic distribution
(BOWIE ACS So asaceseasseos] she coos veesesaecciases 100
type specimen figured . Pl. XV, fig. 8
sp. undt. f, described ....--.----- 423
compared with Obolus sp. undt. e...-.----.---------- 423

INDEX.

Obolus, sp. undt. {—Continued.
general geographic and stratigraphic distribution tab-

TU ee Chetan ceeeerctee eet cose stmie te cies eee eee 100
type specimen figured ....................... Pl. XV, fig. 9
0), Beals. Cee) 5 eo So sen sca secopee bere anesesesecose: 423
general geographic and stratigraphic distribution
TATE «ae eoaccosescoseodacobsssasesoodcosases 100
type specimen not figured.
Obolus conglomerate, in generalized section for Russia, listing
species and localities 144
mienhione demeree ter asee eee see 419
Obolus conglomerate (Upper Cambrian), localities from sandstone
DEON se ddecioe sone nes Spee ee eseamaoseseadecacensnssacoaS 395m-r
Obolus conglomerate (Upper Cambrian), localities in...-.....----- 9e,

336i, 3901, 395f-1, 395s—u

Obolus sandstone (Upper Cambrian), in generalized section for
Russia, listing species and localities......-....----------- 143

in generalized section for Sweden, Denmark, Finland, and

Norway, listing species and localities. ....-.-..-..----.--- 145
IG GANS Ti. 5 6 sasscsaneoseronsdesescoseusce 9d, 310n, 31ly, 31lw,
$21, 32la-d, 3210, 336a-c, 336j-m, 336r-u, 395, 395a-e, 395z
MATMNMGMG 2 3 osscscacesae sesaeonoEesescaoseosseace 390,391, 408, 413
Obolus (Acritis), described ...-...-..---.-.--.-------------------- 437
GiOAGIRMNACL.-65 o os cocoaopedoceccoodseeovEnSsconeooes 377
CE SSIACIOM Of, . 9 n6-ssososnonoSsosasesocsccepoas: 321,323
compared with “‘Huobolus,” “Schmidtia,” and ‘“ Thy-
SCMOLOS 2» Diya MUCK Wat Zale paets see sie ee ee eee 434
CUOMO Or 45055 ccosseasscosssessseosseescoassons 317
general geographic and stratigraphic distribution of
the species referred to..--...-.-...--.----.------.-- 101
general stratigraphic distribution and number of Cam-
brian species and varieties of................-.----- 110

MACMPOVANl,..- .35-cceocossa0 52 beossoseeasccosacassenS 427,441

numbet of species of, in different types of sediment... 160
stratigraphic range mentioned......-..-..--...------ 379.
surface ornamentation discussed. .....-.-.--.-------- 301

type species “‘Obolus (Lucina) antiquissimus”’ ...-- 377, 437

antiquissimus, described ......---------------------- 437
compared with Obolus obscurus....-..--.------------- 407
Obolus (Acritis?) rugatus....-....-.------------ 441
Obolus ( Mickwitzella) siluricus....-...-------- 435, 436 ~
Obolus (Palzobolus) ------- PLE ce bacceoeoeencse 426
Obolus (Palzxobolus) bretonensis - - - - se | Y/
“Obolus ( Thysanotos) siluricus”’ - 377-378
general geographic and stratigraphic distribution
tabulated Berean pe cesar ieee ene ene ees aie iae 101
type specimen not figured.
PUHMG, COSMO. - — saecqesecoss coddosseoorasecbsenescaobes 441
compared with Obolus obscurus.......-.-------------- 407
ev olmblonyGiscrsse dese se sess eet 318
general geographic and stratigraphic distribution tab-
WIEHACko- cas ses ssooddoonbbosonoeo panos semeNSceEGNOS 101
type specimen figured
Obolus (Bréggeria), described.......-..--.--.---------------------
QUOECHEVAt es og c4ssopnqnc esas coscanon sqesaauesaces6

classification of...
evolution discussed

evolution Ofeccs- see aeeee cease =e 317
general geographic and stratigraphic distribution of
the species referred to......-...--.--..---.---.-...- 101
general stratigraphic distribution and number of Cam-
brian species and varieties of 110
number of species of, in different types of sediment... 160
stratigraphic range mentioned...-........-...--.--.-- 379

type species “‘Obolella salteri” ........--.----------- 377, 424

Sib ai, GESOM NG 6 cee 52-6 soon sencoososesesbsseasconescoes 424
compared with Obolus sp. undt..a....-..-..--.-..-.-- 422
general geographic and stratigraphic distribution tab-

ulated......- SUAS SoS adRA CAC HON BSAbs oncbodoaDeneess 101

type specimen figured ...........-...-------. Pl. XV, fig. 4

“ Obolus (EHoobolus) discus,’’ discussed - 536

sasasodcoad 536

Willi, WRG ppp peceococnenssempseoccossscsce6ecHoacenece 380

Obolus ( Fordinia), described........--.--------------------------- 428

(CHATACTERIZE Cease eete oe tele eal lee 378
classification of...-.-.----.--
development........-----.--

evolution discussed..........-------------------------
AVON O8 noseacs scoot deaoeeaestonsocsonsodssscacce

855

Obolus ( Fordinia)—Continued.
general geographic and stratigraphic distribution of
the species referred to .........-.-.---.------------ 101
general stratigraphic distribution and number of Cam-

brian species and varieties of. ...----- 110
intermediate between Obolus and Eikania.. on 428
mMUScleISCaTS|CISClSSe 0 eee ee === se eee ee eee eee 312
number of species of, in different types of sediment... 140
stratigraphic range mentioned............--.--------- 379
type species Obolus ( Fordinia) perfectus -- 378, 428

bellulus described: a. ease. sce oc ce ene eee oie eer cece eis 428
compared with Obolus apollinis.............-.-------- 562

Obolus ( Pordinia) gilberti..........-.-.------- 428, 429
Obolus ( Fordinia) perfectus --. 428, 430
general geographic and stratigraphic distribution tab-

Ulated Se Re See eset RES eee ne tae eects 101
platiormymentioned asses seal ee sse see Ee ee eee eee eee 310
type specimen figured ..........-.-.........- Pl. LI, fig. 3d

(PLDT py COSMAS. Ae cancaannobesads ses odemedansecbecsoes 429

compared with Obolus ( Fordinia) bellulus -..-..--.- 428, 429

Obolus ( Fordinia) perfectus ..........-.-.----- 428, 430

confused with Dicellomus politus - .. -. bebecssssess9005 429
general geographic and stratigraphic distribution

tabulatedteee cesses asec cece de ceca eee eeeemceeie 101

MET ONreN HAG AONE ~~~ oengreccsosoepacasesucacesoee
typeispecimen figured-----22---2-2.--.--.----
perfectus, described...........--.-.--
compared with Lingulella clarkei.
Obolus ( Fordinia) bellulus -
Obolus ( Fordinia) gilberti
developmentiotemeseareee neat sessceee eases eee
general geographic and stratigraphic distribution

UO UIENGIC on oemcoetsonecensoeeecoussssureucsudenes 101
intermediate between Obolus apollinus and Elkania

CRTUGTEM ms Gaaaasbseson Soon as eR epSconAeodaaNeS eoane Bill)
muscle scars in, discussed 310
platform discussed -- 310
type of Obolus ( Fordinia) 378, 428

type specimen figured. -_......-......... Pl. LXIIL, fig. 10a
“<Obolus (Leptembolon) lingulzformis,”’ type of Lingulella (Leptem-

WOM) acececcecoscsescessceesonssocanccesgb Soasdteaseans 474
“ Obolus (Lingulella) bicensis,” discussed ........-....-.---------- 605
Obolus (Lingulobolus), described. ..-....-- 430
Characterize desess- see aeons iaceise eens eec eee 378
classification of. -- 321,323
compared with Lingulella.............-.--...-.---- 432, 472
OWS = 22222 zo 02 2022 Osos opessESzeensoeossens 433, 434
evolution discussed 318
QUOI Oi. 635505 coecc opacoonessosobceeseencsorses 317
general geographic and stratigraphic distribution of
thejspecies referred to. ----------02.---.5-22-----.-- 101

MAM POMH! 252 seosnessossadosconssossee0seessc09 379, 471

number of Ordovician species and varieties of..._._._- 113
number of species of, in different types of sediment... 160
old-age characters discussed. .............-.-.--..-..- 315

stratigraphic range mentioned.......................- 379
302

surface ornamentation discussed .........-.-.-.--.-.-
type species Linylilella ? affinis. -..

(jMS, CESOMU A - - 552205 s8s2ascaoe s2cocseosseezceececosses 431
compared with Obolus feistmanteli..........-.--.-..-. 392
general geographic and stratigraphic distribution

TONE. ooocsconnane qaorsposansseceocsscocsaeance, 101
type specimen not figured.

GERUS, COLONIC 4 ot s-cacspcoons sesso cesssecdseccaspandes 432
compared with A crotreta idahoensis..........-.-.----- 688

OUHGMO GRUEBSH » see oescbotodss6eH5s aoosasoqaoNEs 594
Obolus (Lingulobolus) affinis - 432

general geographic and stratigraphic distribution
tabulated herceeee rs oremens seston an eee te 101

type specimen not figured.

“Obolus (Lucina) antiquissimus,” type of Obolus (A critis)....... 377, 437
Obolus ( Mickwitzella), described 434.
characterized. - 378
classification.....-.-.---.--- 321,323
compared with Obolus (Acritis).......-.-------------- 437
evolution discussed......-.-.--------------------,---- 318
evolution of 317

general geographic and stratigraphic distribution of
tihe}species melerredstOsesees seme eeeene eee == 101

general stratigraphic distribution and number of
Cambrian species and varieties of...........-------- 110

856 CAMBRIAN BRACHIOPODA.

Obolus ( Mickwitzella)—Continued.
number of species of, in different types of sediment.. 160

stratigraphic range mentioned. . . 879
type species “‘ Obolus siluricus”’.. 378, 434
SUUUTECU Sy CCSCILDE Coton = 2 setae ee ee 434
compared with Obolus dolatus......------.----------- 390
Obolus (Acritis) antiquissimus 439

general geographic and stratigraphic Gsintoestion
tabulated === see eee eseee eet Ree eee Eee eens 101
surface ornamentation discussed.........-.----------- 301

type specimen not figured.
Obolus (Palxobolus), described ......---.------.------------------ 426
Characterized ee e= eee eee near ceeee eee eee eer 378
classification of. 321,323
discussed 253 (oa- cnet ee ere eee eee Sere eee 427
evolution discussed..-...-........--...-....---..-.--- 318
evolution of 317
general geographic and stratigraphic Samstawiion of
thejspeciesineferted Osmes sss o-eneeeeeacee eee 101

general stratigraphic distribution and number of
Cambrian species and varieties of ..............-.. ce I®
number of species of, in different types of sediment.... 160
stratigraphic range mentioned.............--.-------- 379
type species ‘‘ Palzxobolus bretonensis”........------ 378, 426
OTELOMETISIS, (LOSCED CUE ee eee ee eee eee 426
compared with Lingulella (Lingulepis) rowei........- 558
Obolus acadicus-..------------22----2-- - . 380
Obolus (Palzobolus) bretonensis lens 427

general geographic and stratigraphic distribution
TOE. i ose ino nnobesancasosonode tose Ssosscncos

type specimen figured
bretonensis lens, described ..-......-..--.-.--.--------------
general geographic and stratigraphic distribution tab-

DUEVIEG|. asco se nooo cee sacostaodaenoosesoeseocesses 101
type specimen not figured.
bretonensis lens longus, discussed . 427
Obolus (Schmidtia), described-...-..-. sace., Guat
Characterize Gers amemisam nese ena n= se ceisee soe Seeiecigs se 378
GSS HiOM OF 2 see = ssp scceqosscgcorsece ss seensecin 321, 323
compared with “ Acritis,’”’ ‘‘ Huobolus,” and “ Thysano-
tos’? by Mickwitz ‘ 5 434
SEUNG ULEL UD = steel orem aise eee -- 472
Lingulella (Leptemboton) lingulzformis ........- 543
Obolus complecus....-...-..-..--.-.------------ 388
evolution of 317
general geographic and stratigraphic distribution of
(HOS SOLOS) WENA! WO) 52s ssenoscossceosaaeesesess 101
general stratigraphic distribution and number of Cam-
brian species and varieties of...............---....- 110
MANO MAC. 5 -coosssseeoossncsedoesesrasseoeess 318,375, 471
number of species of, in different types ofsediment... 160
relative position of vascular sinus in species of_..._... 376
species and varieties recognized by Mickwitz, listed.. 380
stratigraphic range mentioned..........-..-........-- 379
thickening of shell beneath visceral area discussed.... 310
type species “‘ Schmidtia celata”’.........-.-.-...---- 378, 442
ACUMIUNGLUS 1G ESCH) Cena ee eee sae eee eee 449
compared with Bicia gemma 570
Obolus (Schmidtia) crassus..............-.------ 447
general geographic and stratigraphic distribution tab-
Tila be dite crepes casera ste ore ceeie some soae eee 101
type specimen not figured.
acuminatus alatus, mentioned...............--------------- 443
CELTTUS CESCLID CO semesters aise ore ine ee oa terae nee Eee 444
compared with Lingulella davisi.......-...--..-----.- 472,
Lingulella granvillensis........--.-.------------ 471
Obolus (Schmidtia) acuminatus.........-.....-- A43
Obolus (Schmidtia) crassus.........-..------- 447, 448
Obolus (Schmidtia) obtusws. -. 449, 450
general geographic and stratigraphic distribution tab-
IRIE Soa dooeebeadsoccesccopesEOseESneEEsosocenne 104
netlike coating of, which resembles a bryozoon...-..- 445
type specimen not figured.
celatus orbiculatus, compared with Obolus (Acritis) antiquis-
: SUMUSN Se ose aes ove gee ae 440
mentioned 445
celatus prxcisus, compared with Obolus (Schmidtia) acumi-
443
445

Obolus (Schmidtia) crassus,described..............--.-.---------- 464
compared with Obolus tetonensis ninus 418
Obolus (Schmidtia) acuminatus..-...------------ 443
Obolus (Schmidtia) obtusus ..........---------- 449
general geographic and stratigraphic distribution tabu-
101
type specimen not figured.
obtusus, described. -..-- Ne ES a SE Seles mete se met yeaa eto 448
compared with Obolus (Schmidtia) acuminatus ......- 443
Obolus (Schmidtia) celatus......-.-.------ 445
Obolus (Schmidtia) crassus 447
general geographic and stratigraphic ‘distribution tabEe
Tated is) isc doc ie sehen Sasotete sone sae See S seer 101
type specimen not figured.
ODUIUSUSILO77G 2139101 e Tit] OT) CC eens sean aes ete ete eee 449
“Obolus ( Thysanotos) siluricus,’’? compared with Obolus (Acritis)
QNUIQUISSUM US so ea see neL ee Cele Beets 377-378
Obolus ( Westonia), described. ..-.--
characterized . ..- Fie
Classification of........
compared with Acrothele...........1...-...-.-.-.---- 631
Botsfondia soe ees ach fo tee See a 602
Schizambon ? esthonia. 622
evolution discussed 318
evolution of, 317

general geographic and stratigraphic distribution of
the species referred to----..-.-.-----.-.------------ 101
general stratigraphic distribution and number of Cam-

brian species and varieties of 110
mentioned 379
muscle scars discussed 312
number of Ordovician species and varieties of-...--.. 113
number of species of,in different typesofsediment... 160
relative position of vascular sinus in species of-......- 376
species referred to classified according to surface orna-

mentation=-227 ekeos she eee see ee eee 450-451
stratigraphic range mentioned..........-.-....-.-...- 379

surface ornamentation discussed... - i

type species ‘“‘ Lingula aurora” ..........--.--------
Glandensis, described sta... 02 -eeaseeea- 2 eee see eee ees

general geographic and stratigraphic distribution tabu-

lated’): -s25o-thiesoy cee ewes eee 101
surface ornamentation characterized... 451
type specimen figured.............-.-- Pl. XLVIII, fig. 6a
@urora, Aescribed a... =a ene omen se Sones See een 451
compared with Lingulella (Lingulepis) starri ---- 509
OUOTUSMCCOTT ELL ene eee eee eee eee 396
Obolus (Westonia)\ellas= = = ens en=nee eeea 456
Obolus (W estonia) euglyphus.........-------- 461, 462
Obolus ( Westonia) stoneanus.......-......---- 465, 466

general geographic and stratigraphic distribution
LOIN oe asec Seceshosesoessonussseesseors 101
surface ornamentation characterized.......-.... 301, 450, 451

type specimen not figured.

GQUCTS CESCULD CO nme ene E Ere Seer er eer eee eter 453
compared with Obolus ( Westonia) dlandensis......--.. 451
Obolus ( Westonia) blackwelderi.........-.-.----- 453,

general geographic and stratigraphic distribution
DOULA Spanos cope ena oessudssozsoeescen 101

stratigraphic position of bowlder containing, dis-
GUSSEGL 2 se ee oc ot secse cobsonnesovseoss cus roosses 454
surface ornamentation characterized..........-..--.-- 451
type specimen figured..........-...-.. Pl. XLVIII, fig. 7b
blackwelderi, described....-...--.----.-.----.---.--.--.----- 453,

general geographic and stratigraphic distribution
(EUG - escapees tcdssesssoesseessvosbegscons 101
type specimen figured............- Pl. XXXIX, fig. 10
botimiciis iC CSCil be seee ener ene eee ee reer ee ater 454
compared with Obolus ( Westonia) dlandensis........-. 451

Obolus ( Westonia) elongatus...
Obolus (Westonia) finlandensis.

Obolus ( Westonia) wimani....-..-.------------- 467
general geographic and stratigraphic distribution
tabulateduc*: sens sees tees aeeeeet steno ene co UO
stratigraphic position of bowlder containing, dis-
GUESUGl ss 5cso5c -osedese se seceseceseecsaeErse 451, 454, 684
surface ornamentation characterized..---.--.-.----.-- 451
type specimen figured.......---..----.- Pl. XLVIII, fig. 4

|
:
:
:

ee

INDEX. 857
Obolus (W estonia) chuarensis, described.........-..-..--.-------- 454 | Obolus (Westonia) iphis, described. ...-....-..-.----------------- 462
compared with Lingulella dubia... 495 compared with Obolus ( Westonia) Fatcientts 463
Lingulella quadrilateratis...-- 528 general geographic and stratigraphic distribution
Obolus ( Westonia) euglyphus. 462 tabulatedin: ibe) sce er Cee eee enee se cet cece 101
general geographic and stratigraphic distribution type specimen figured .......-..------- .. Pl. XLIX, fig. 4b
HAUTE Oa see Nese A stm crs et Oe to Nee erm lamellosus; described eseeese sae cee seaeenes eee ae === 463
surface ornamentation characterized. general geographic and stratigraphic distribution
type specimen figured...........--.. tabullatedan (cop ie clon fo aeeeeeeeeere setetysrciniccicsla 101

dartoni, described surface ornamentation characterized .........--.----- 451

general geographic and stratigraphic distribution type specimen figured ..-...:-.-..-..-..-.--- Pl. XI, fig. 7
VEL WIDICG A ChesdoasecbbEsduedsonceoaaseenscesasbes55 101 motchensts.) 0 eSchibedeer a eeeeee eeeeeee eee eee eee ees eee 463
type specimen figured.................- text fig. 40A, 455 general geographic and stratigraphic distribution

ellamdescribedeee eric ctite ae sone ke oe cae cise Daten sie ee oa aeoee 455 tabulated {\.2. et ee Se Oc eee eee nese 101
compared with Acrotreta.......--.-. oO type specimen figured . ans .. Pl. LXIII, fig. 9

Acrotreta bisecta..-....-.------ aeee G74 rogersi, Gescribedesne an. qqueeec ne ae eee eee 463
Acrotreta gemmula.....-.----- -- 674, 686 compared with Obolus (Lingulobolus) affinis 431
PATCH OT CLO NUIVIICL Ose aerate eiseieeinicice inieisecioe 674 general geographic and stratigraphie distribution
Acrotreta primxva.....-.-----------+---+- 672, 674, 700 tabulated ss ety cites cise eee ciate Eee eee 101
Acrotreta sabrine. . 674 surface ornamentation characterized .............-..- 451
Lingulella bellula. 482 type specimen figured -..-.-..--.-.....--.. Pl. XLII, fig. 2
Lingulelia dubia 495 SLOTeEaTUS 1d escribedeeneaaaekneenerneeecniceeeeeee enone 465
Lingulelia grandis 502 compared with Lingulella Isami eee loo atctarseee saree 512
LEO ETN IGEN, 6a Sa senonson[-eerosscsesos 506 PER NOULELR OWEN aan aa eee eee eee seca 523
Lingulella mosia 520 Lingulella wellert ....- . 539
PETIT LLELLGAON Gemreetotyay entre sereticieietiaiseisee es 522 Obolella (Glyptias) favosa. 600
PN GULELLONT COLI Cee eee eee eet eee 629 Obolus ( Westonia) lamellosus....-.....-.-- 463
Lingulella (Lingulepis) roberti......--.--------- 557 Obolus ( Westonia) notchensis .......-.------..-- 463
Obolus fragilis. ..-...--- 22s ence ewww nnn ene 393 Obolus ( Westonia) rogersi......-..-..---------- 464
Obolus ? mirandus - 405 general geographic and stratigraphic distribution
Obolus refulgens ... 410 tabulated eee. eh nee tice oes heaton sak oe cece eee
Obolus ( Westonia) alandensis........----.------ 451 surface ornamentation characterized
Obolus ( Westonia) aurora ......--.------------- 452 type specimen not figured.
Obolus ( Westonia) chuarensis.....-...-------- 454, 455 themis,idescribed eee eae cece ae seer csisce soe essence pene ae 466
Obolus ( Westonia) dartoni 455 general geographic and stratigraphic distribution
Obolus ( Westonia) ella onaquiensis .......--.--- 459 tabulated’: G27 tee asics rsstie tne oe asin seisaee ere 101
Obolus ( Westonia) euglyphus......----------- 461, 462 ‘ bypelspeciment fered eamerteee eee sees eae eae e Pl. XI, fig. 2
Obolus ( Westonia) themis:.........-.----------- 466 MORAG OSS, CEC NAC = = soap ences coséoossosvocoosoase see 466
Obolus ( Westonia) wasatchensis......-.-...---.. 466 general geographic and stratigraphic distribution tab-
Obolus ( Westonia) sp. undt. a....-.--.--------- 468 At Cys vets aes acme eer cere lees erepe eet 101
general geographic and stratigraphic distribution typeispecimen|figured)==-2 22-5. - nose text fig. 41A, 467
tabulated) s25s2aoecsccce tsscke ne eenee cc deceee ence 101 OHM ii; COROM NACL = sseoc jacoeasostaoessosossaencosoe0aeG 467
surface ornamentation characterized................-- 450 compared with Obolus ( Westonia) dlandensis......-.- 451
type specimen figured... . Pl. XLVI, fig. 1b Obolus ( W estonia) blackwelderi......-...--..--- 453

ella onaquiensis, described.............-..-------+---------- 459 Obolus ( Westonia) finlandensis.........-...-..- 462

general geographic and stratigraphic distribution general geographic and stratigraphic distribution tab-
tabulated ie as sscetemce cacti tees ene e ee eece ceeae 101 MB KGlS 4 So sGeesbSscoscosudtoousaadestoaseecedesesbS 101
type specimen figured . Pl. XLIX, fig. 6 stratigraphie position of bowlder containing, dis-

elongatus, described .......-.-..---- 459 GUSSOG sooo soasesesensoronsagSno as secon ucdsess 451, 454, 468
general geographic and stratigraphic distribution type specimen figured . -- Pl. XLVIII, fig. 5

telbulla ted nemrnecterecine co erienacinena em ea ee ae 101 Shop, ital, By, CSM Ot. Coc peno soso aceeooecceonseoseseaseas 468
type specimen figured.........-.-..-.-.- Pl. LXIII, fig. 8a general geographic and stratigraphic distribution tab-

eScasomi, described seccn ne ees eie ene enema seen se eee aaa 459 WE as ocdareanssaqco joes scossuceauoascesuases 101
compared with Obolus apollinis..........-----.----- 460, 472 type specimen not figured.

Obolus wortheni 421 So}: Hiatsliy, 19), COSC MG oo oso sos opsoo se sceecoempbSeeseesoees 468
general geographic and stratigraphic distribution general geographic and stratigraphic distribution tab-
Raul abe dene rere sea aaa nema e ieee veer 101 WENGE poe téaccsadoscctscpe ssp scdedeseeneaaasesence 101
muscle scars discussed............ 312° type specimen not figured.
, Surface ornamentation characterized. . 451 | Obookhoy, see Obuchow.
type specimen figured............- Pl. XLIX, fig. 1a | obscura, see Billingsella.

EGU DUS ROCSCLI DCO eet ee eerie eee ee ee 461 | obscurus, see Obolus.
Cardinalianeaidiscussedeess-ssseesseoeeeeeeeeeeeeeonee 304 | Observatory Hill, Maryland, locality on..... Oe Ag ere eR 47%e
compared with Lingulella lineolata.......-.-..-.-.--- 516 | obtwsus, see Obolus (Schmidtia).

LEUNGUACLLO WIS 2 fee ase hee cae eae eee oe eee 538 | Obuchow (Obookhov), St. Petersburg, Russia, locality at........ 337j
Obolus ( Westonia) chwarensis.......-.-....--- 454,455 | occidens, see Mickwitzia.

Obolus ( Westonia) dartont ...-...-........-...- 455 | Odensholm Island, Esthonia, Russia, localities on... ..- 336b, 337c, 395v
(Obolus| GWestont@) closes epee eee ee 456 | O’Donnell and McManniman’s quarry, Newton, New Jersey,
general geographic and stratigraphic distribution locality sine 53 sstesmccn center eee acesee cece cceeeseen sees lle

tabulatedena-.2----26ee sees noe Oehlert, D. P., bibliographic references.......-.-.......-...-..-- 22
surface ornamentation characterized. clandica, see Acrotreta.
type specimen figured .....-..--....... Oeland Island, Sweden, localities on_....................-........ 8z,
Hilandensi ssc escriped a -me re eee ae eee Eee eeee eee eer ee eee 309f, 309j, 309m, 310, 310a—g, 310i-k, 310m, 3100, 310p, 310r, 310s,
compared with Obolus ( Westonia) bottnicus........- 454, 684 310w, 320g, 320p, 320q, 320s, 321x, 390, 390a, 390c-e, 390i, 390m
Obolus ( Westonia) elongatus...-......-.-....---- 459 | Oestersund, Sweden, locality near........-...........-.----...-.. 3201
Obolus ( Westonia) wasatchensis.......-.-.-.--.- 467 | Ofverby, Aland Island, Finland, locality at.................-...- 311t
Obolus ( Westonia) wimani......----.---------- 468 | Oregrund, Sweden, locality near...............--------2+-------- 31lv
general geographic and stratigraphie distribution Osthammar, Sweden, localities near..............-..------- 3lla, 31lp
tamlatedstre ta. vine see teers atcimeeicientlsac sie 101 See also Fanton Island.
Stratigraphic position of, discussed ...-.....--.--.-- 451,454 | Ostra Rynninge, Sweden, locality at..............-...-.-------- 320u
surface ornamentation characterized ....-.-.-...----- 451 | Oxna (Oksna), Norway, locality at.............---.------------- 323u
type specimen figured..........-----.- Pl. XLVIII, fig. 3 | Ogden, Utah, localities east of................-----.------ 30p, 30q, 30s

858 CAMBRIAN BRACHIOPODA.

Ogden Canyon, Utah, localities in........----.-.--------- 30p, 30q, 30s
Ogof-ddu Cliff, near Criccieth, Wales, locality at..........-.--..-. 3183
Ogygopsis zone (Middle Cambrian) discussed and fauna listed... 127-128
Tgyembiinny thts goaaebepbaenoeaoscons [spec aascenosaocacdeceencos 14s
mentioned. -.. 724
Ogygopsis klotzi, association mentioned. ....-..-----.------------- 354
Ojo de Agua, Argentina, locality at........ 389c
Oklahoma, Cambrian species of, listed... . 114-119
detailed section of Cambrian and Ordovician in, listing spe-
Les andy) OCALITICS eee ee See eee 141-142
Nocalitiestinsseeeeessee eee eee 9p-x, 92, 12j, 12k, 12m, 12n, 12p
Oksna, see Oxna.
Old-age characters, discussed........-.-------------------------- 315
Olenelloides armatus, association mentioned ..........------------ 541
Olenellus, association mentioned........-.----------------------- 338,
340, 347, 349, 352, 583, 613, 617, 644, 659
Mentioned see esse e eee eee ee eee 684
Olenellus?, stratigraphic position of bowlder containing, dis-
GQUERIGIE sa sade cnc osbussosddas sso sSbaErnoscsceserosssess 454, 684
Olenellus fauna, mentioned... -. 362, 378, 387, 409, 492, 665, 681, 707, 731, 764
Olenellus zone (Lower Cambrian), localities in ....------------ 142, 396v
men tlOne dee eee see eee eee eet 473, 584, 620, 701
Olenellus gilberti, association mentioned.....--------------------- 656
thompsoni, association mentioned.......----------------- 316, 759
TALS MI LOSAE\Gl 5 Goo a4 sancdoe doosessHadoSoUaeooCooSbOTsEDaS 605
Olenoides fauna, mentioned .......----------------------------- 362, 378
Olenoides curticei, association mentioned......-.------------------ 692
Olenopsis, association mentioned. .......----------------=-------- 584
Olenopsis beds, mentioned ...-..--------------------------------- 332
Olenus, association mentioned 767
mentioneds--sse= ee -e— ee 482,766
Olenus fauna, mentioned 557

Olenus zone (Upper Cambrian), in generalized section for Swe-
den, Denmark, Finland, and Norway, listing species and

eG 55 So coescocssonececosssdbnesoassesseeSsossssocse5 145
localities in 9f, 309m, 390n
WOAH AGT. cascste sels sosasass soeeees eoseeaeseosemesoenece 530

Olenus truncatus zone (Upper Cambrian), localities in --..-... 310a, 310i
TAME! = 42a ssonssse ose odssasosedsosserspeSpoacosdsecs 541
Onaqui Range, Utah, locality in..-.-----..-----------.---------- 33f
onaquiensis, see Obolus ( Westonia) ella. ,
Oneida County, Idaho, localities in..-...---.-.- 4y, 5a-c, 5h, 54s-x, 55d
“ Qneota dolomite” (Lower Ordovician), localities in-.-...... 339, 364a
localities in, mentioned ........-.--..-.--.-..-------------- 159
* Ontario, Cambrian species of, listed. .-........-..---------+--.- 114-119
TeeAiMES Ws 5255 soko sec soe csosonoene Sacenccoe seas 392b, 392d, 392e
note on stratigraphic position of localities in...:...........- 143
Ontika, Esthonia, Russia, localities at-.--....--- 395d, 395k, 395q, 395t
Oothkalooga Valley, Georgia, locality in..............---.--.....- 362
Ophileta beds, mentioned -...-....-- 353b

Ophir, Utah, localities near
ophirensis, see Acrotreta and Micromitra (Iphidella) pannula.
ophirensis descendens, see Acrotreta.

ophirensis rugosa, see A crotreta.

Oquirrh Range, Utah, localities in..-...-....-..-.-....--.-.. 3c-e, 329e

ora, see Lingulella and Micromitra (Paterina) stissingensis.

“Orbicula buchi,” type of Keyserlingia............-----.-------.-- 628
CRICTISSOn ee GISCLISSCO MEE eer er eee eee eee et Eee ree ree 594
“‘reversa,’’ compared with Keyserlingia buchi.............-- 630

Orbiculoidea, described.....-.-.----.-.---------- 722

cardinal area discussed 305
classification of.......-.----- 321,325
QyOlibinorn GWAC. — ~ 565255 5scosecosseoseeessoness 319
OYOMUMOM Oo oceocsooessszesoe ese se eonessereeseneSs: 317
general geographic and stratigraphic distribution of the
HOHE MI MAT! WO) ooe wsose cote SoscoSsssu see seem 107
general stratigraphic distribution and number of Cam-
brian species and varieties of......-...-.......-...- 111
Wisinmibiaa tal. ~~. o2205-2 sessed sssstseesceossessecoesess 306
muscle scars not shown in...-......--...-.-----.....- 313
number of species of, in different types of sediment... 160
reference to, of Orbiculoidea contraria, discussed...... 722
reference to, of Orbiculoidea pileolus, discussed... ..-. 723
reference to, of Orbiculoidea varians, discussed... -...- 723
COMPTON AOCSCUID C0 sen eee eee eee eee eee 722
general geographic and stratigraphic distribution
HBVOWUEMIEG! «soso sas oss possess oe ssesorezeseseess 107

Orbiculoidea pileolus, described .................-.-.-------------- 722,
general geographic and stratigraphic distribution,
tabulated. .--.-..-..-- Bree OeA~m Sen sbeces 107

type specimen figured - - Pl. LXXXI, fig. 11
varians; describedees-ssnec scot ease tare eee Ree eee 723
compared with Orbiculoidea contraria.............--.- (22
general geographic and stratigraphic distribution
tabulated css sees eee nas ce ee ee 107
type specimen figured Pl. LXXXI, fig. 8
Orbiculoides, compared with Discinolepis 664
d’Orbigny, A., bibliographic reference.......................----- 22
Ordovician, Bohemia, generalized section, listing species and lo-
Calities :2 2. $S4. 52 ea ee es eo a Ree Be 124
East Prussia, generalized section, listing species and localities 148
England, generalized section, listing species and localities... 135
families listed . - 113
genera listediy. o Bh ieee Oe eee re aes 2 Se Pie 113,317
Mount Bosworth, reference of, to Sherbrooke limestone

explained ee ere eo ce ee ae eet ROE ee A 125
Nevada, detailed section, listing species and localities...... 139
Newfoundland, species and localities in, listed ............. 140
Oklahoma, detailed section of Arbuckle limestone. ......... 141
Russia, generalized section, listing species and localities... .. 143
Scotland, generalized section, listing species and localities... 135
‘Species'listedeisce5 5) eas cee ae eae ace See nas 98-109
Species of EuTOpellistede esse eeeeeereeeee eee eeeeeeeeeeee 123
species of North America listed.................-...-.---- 122-123
Utah, detailed section, listing included and correlated

MAOES Cael EMIS. 5 comes sabooeceascossesccsoseecses 148, 153
Wales, generalized section, listing species and localities... .. 135
See also Passage beds.

Oregrund, Sweden, locality near.................--.22--22---e--- 31llv

orientalis, see Billingsella, Huenella, Micromitra (Paterina) labra-
dorica, and Yorkia.

Original, see L’ Original.

Orleans Island, Quebec, locality on..........--....-----.----0---- 56b

ornatella, see Micromitra (Iphideila).

Orr formation (Upper Cambrian), in detailed section in House
Range, Utah, listing included and correlated species and
localities::..22gnc cicesessatea.6= seeiecec seer seamceeiceine 153-154

localities in. . 30h, 30j-1, 30y, 31t
MEN TONGM smectic faceless eee em eeasiseereeer - 510

Orr Ridge, House Range, Utah, localities on............. 30h, 30j-1, 31t

orta, see Acrothyra signata.

Orthacea, classification Of- 2 -- <2 - =< seem emcees ance een ae 321, 325
distribution in Cambrian strata.........-.-.---2-.-....---- 316
genera and species referred to, described ................. 725-795

orthia, see Syntrophia.

Orthidz, Cambrian and Ordovician types compared by Ulrich.... 308
compared with Billingsella.........--.-------.o-----ene=ee 749

Billingsellides bya nichises eee eee eee ees 308

CampbmaniBillingsellidtessssee eee ee eee eee Eee erenee 320
Cruralitmmymeniioned seen e = ee eee eee eee ee eee 309
Ordovician and Cambrian types compared by Ulrich....... 308
pseudospondylium discussed..............:....-----...-- 307-308
Schuchert on development of 308
shell structure compared with that of Billingsellidee........ 300
Ulrich on development, classification, and relations of.....- 308

Orthidee (Cambrian), compared with Ordovician Clitambonitids
Dy Umeha rs eke see te | ae 308

Orthis, classification of, by Ulrich...-..........-...-...-....--.-. 308

compared with Billingsella..............--....----- 772,773
OOTERIS shez ipyaei a aiacoeeteea eee eae sae eee 772, 773

OTUSI 2 3.52 Se oe RSS DIT eee ee 765

Protorthisecias + Je seeise ss eee ee eee 739

Wynnia BaBetOnE obs Rcaudeaneecosac 771

CLuraliim nent One Caen = see ee es eee 309
GISCUSSCdiea= ee ene aae a oe nee eee 772
Gvolutiontdiscusseds===eesee sees e ee see eee eeee 320
evolution of .....-- PRCA OHS RASA AO BEDS ARS AsRaeS 317
mentionedtessee se 2e eee eee ---- 785, 785, 788

no Cambrian representatives. -...-..---.---.---.----- 320
presence at Hastings Cove mentioned. ......- sesos002 779
pseudospondylium discussed..-.......-.-.---.-----.- 307
reference to, of Hoorthis atava discussed - 774
EQULUQIUTSy DA CTL OTIC Ue eee eee ee eee 772
? armada, reference to Syntrophia discussed.-......--.---.- 798
“barabuensis,’’ mentioned ..-.--...---.--------------------- 798

ee

INDEX.

Orthis “biforta,” compared with Syntrophia barabuensis......--.... 799
callactis, type of Orthis (restricted). ---...-.-.-.------------5 772
callactis-tricenaria group, compared with average Cambrian

RIEU lyr Wiidielel 3 5 Soo aeecuneooseEsaescpessacostoosS° 308
calligramma, mentioned..-......-..----.--- 772
“christianiz,”’ forms referred to, differentiated... 7715

IBNOP Per | CISCUsse descr sees eee nee «te

Gareln discussed exc. = oh2-tcis= > ..oese ee eee 776

PYOCIMOCTY GISCUSSE Gerais os =a sects Sool eee eee ters 776
“coloradoensis,”’ type of Billingsella 749
“exporrecta,”’ compared with Hoorthis linnarssoni...--.----- 783

discussed 755
fissicosta, mentioned 772
flabellites, compared with Plectorthis whitfieldi by Ulrich.... 308
“hicksi,’’? compared with Hoorthis linnarssoni..-.-.-.------- 783

ISCTISSE MEME eejeisseias sense Se istae ee eee ace eee 755
“mflexa,”’ compared with Nisusia ? vaticina......-.---.-..-- 730
HRA, HEC O NG = obo aoc enaapoeseoseesossoReacoascons a 712
“kuthani,’’ compared with Nisusia (Jamesella) perpasta.... 736
CTS, Wa NHAC! once naccosaooeoseesaoeacocscccess 731

“Tenticularis? Kayser,’ discussed

“lynz,’’ compared with Hoorthis primordialis........------- 785
menapiz, compared with Hoorthis saltensis......-.---.-.-.- 788
Spores alman/ 1 CiSCUSSeG eeete a= nee sean eee eee seeeene 776
“nepina,’”’ compared with Clitambonites .....-..--.--------- 739
MiISCUSSe dec eo seisse fhm caince ects ot ceeeeee eeeaeee 749
“‘plicatella,”’ type of Plectorthis Hall and Clarke...:........ 772
“primordialis,”’ association mentioned .......-.....---.----- 735
OTA? Tin of) Ot JRA soc a sae sense osc ees neeSoeoeosco 773
“romingert,’’ compared with Nisusia ? vaticina. seo) (AM)
compared with Nisusia (Jamesella) kuthani ...-.-.--- 733
“Orthis sp. Pompeckj”..-...-----. 793

“saltensis,’’ compared with Orusia lenticularis 768

IMEDIUIONG OE syste ss aters ots eo ata eee eae 499, 767
“Csandbergi,”’ type of Otusia .......-...---.---- BDOdasnOnE oes 769
simuata, mentioned....-.--..------------------ J
“striatula,”’ compared with Nisusia? vaticina..

MENTON CME Aree sates cia). smile eters eee
subquadrata, mentioned

tricenaria, American representative of Orthis callactis....... 772
compared with Billingsella romingert by Ulrich 308
Dalmanella subequata by Ulrich-- SOS
muscle scars of, discussed by Ulrich.-.....-.-.--..... 308

See also Orthis callactis-tricenaria group.
Cn DLCOtelLa pMeNTIONe Meee eee eee eee ee ee eee eee eee eee 772
tritonia, muscle scars of, discussed by Ulrich. ..... 27808
“‘vaticina Salter MS.,”’ discussed.........-.-.-..--.- 730, 731
“sp. Kayser,’ discussed..-..............-.-.-.-.--.-- 767, 768
discussed and compared with Orusia lenticularis.....- 789

SDebom Neck} CIscusse Cte eee meee seat ee eee eee eee 775, 793

“Orthis (? Orthis christianiz) Roemer,’’ discussed...............--- 776
Orthis (Billingsella) laurentina, compared with Plectorthis whit-
fieldi by Ulrich....-.-... seoconesoor cos sass seeosoosscoszoeneoscese 308
Orthis (Dalmanella) parva, compared with Hoorthis......-.-...... 773
“Orthis ( Finkelnburgia) finkelnburgi,” type of Finkelnburgia.....- 794
“Orthis (Plectorthis),’’ discussed a UP?
reference to, of Billingsella retroflera discussed....-.-.-...-.. 761
reference to, of Otusia sandbergi discussed.....-..-.-.-.-.-.- 770
Orthisina, compared with Kutorgina.........-...-.------- - 579
Protorthis 739
reference to, of Hoorthis johannensis discussed. . - 781
reference to, of Nisusia ? vaticina discussed........-..-- 730
reference to, of Nisusia (Jamesella) pellico discussed .- 735
“adscendens,” compared with Nisusia (Jamesella) pellico .. 735
CSO? UNAD® OF INU 6 ceo 52obcccensqessocecauscuene 725
“orientalis,’”’ compared with Hoorthis johannensis...-..-.-.- 781
“nepina,”’ compared with Hoorthis johannensis ....-.-.----- 731
Orthoceras limestone, in generalized section for Sweden, Denmark,
Finland, and Norway, listing species and localities. .....- 144

systemic reference discussed.....-...-.-.-----.------------- 98
Orthoceratite limestone (Passage beds), equivalent to the Vagi-

MLOCENGS LIMeSTON Oise pss sts eee eee See ae cinc eee aerate. 628

in generalized section for Russia, listing species and locali-
WES cok dense ee Sega ROSH eR Neon GH aE aomebSaEBasReseereetes 143
localities in.....-...- 336d-f, 336z, 337, 337a-c, 337f-h, 337j-m, 390
Orthoids, canal system mentioned............-.---.------------- 312
Orthostrophia, classification of, by Ulrich... oe Jets}
no Cambrian) representatives. ..-.--------2----------------- 320
Orthothetes compared with Hostrophomena..........-..--.-------- 796

Orthotichia, classification of, by Ulrich. . 308
Onusia,idescribedseeeeee ese eeee eres se GD)
cardinal area discussed-..-..-..-...-..-.--.....--.--. 305

classifieationlot-seese sen oe eee eee eneeenee esc 321

evolution of 317
general geographic and stratigraphic distribution of
thejspeciesineferred tosses eee eee a 108
general stratigraphic distribution and number of Cam-
brian species and varieties of 111
muscle sears discussed.......-...---------------- Be) 133
number of species of, in different typesofsediment.... 160
stratigraphic position mentioned.........-....------- 320
type species “‘ Anomites lenticularis”’ 765
Ulrich on spondylium...............-...-.----- 308
vascular markings diseussed......-..-..----- 312
PEUTEKENSTS AC CSCLIDE Uae nee Eee ee ae eee eee eee eee 765
general geographic and stratigraphic distribution tab-
tlatedl oe esccee see ed Soaceee Eee mace ee eee oe

type specimen figured.
lenticularis, described

compared with Orthis sp. Kayser...-....-...--------- 789
Orusia? eurekensis ...-..-- ee eae secre ee 765

general geographic and stratigraphic distribution tab-
WEL Se aeat ee AaB ERE Cae Sem amecsrind Maca ceoe 108

type specimen not figured.

lenticularis atrypoides, described 769
@iscussed\s cess! se eee ose eeee bawesececaseents 768

general geographic and stratigraphic distribution tab-
UMlatedl. 3 ais ee RA See water era he es _- 108
typelspecimenthipunedseseseee eens Pl. XCVIII, fig. 5
lenticularis lyncioides, described...........--......---.----- 769
Giscussed ase esi eas os o/s eae area ere moet 768

general geographic and stratigraphic distribution tab-
Mate Oe Ma Sees ve dte Gere Sey eee pne eee cence 108
type specimen figured...............---.- Pl. XCVIII, fig. 4
lenticularis strophomenoides, discussed.......-.-.-.------.-- 768
Osceola, Nevada, localities near.......--........--.- -- 8m, 8n, 10w

Osceola, Wisconsin, localities near.... 78, 78b, 78c, 78s, 328b, 328m, 328n
osceola, see Finkelnburgia and Lingulella mosia.
osceola corrugata, see Finkelnburgia.
Oslo, near Christiania, Norway, locality at....................-..
Osthammar, Sweden, localities near............-------------

See also Fanton Island.
Ostra Rynninge, Sweden, locality at
Otisville, Minnesota, locality at.....
Ottawa River, Quebec, locality on..-...
Ottenby, Oeland Island, Sweden, localities at........... 310, 310r, 390e

323m

Oni, CESGM 9WEl 3 00 ss scs5cs2cs0 0s cco ssNSNSes5eCNsONseancsoCeess 769
cardinalllarearcliscussed=eeee eee eee ee tee eer eee ene nee neas 305
GESSHAEN MOM Oiacose onoce seecescaocssede cece seaconsee 321,325
eV OlUTION OB are emeriyeci sees sa ee eee eee ce enacacee 317
general geographic and stratigraphic distribution of
thelspeciesireferredstose eee eee eee renee etna 108

general stratigraphic distribution and number of Cam-
brian species and varieties of.....................-.- 111
number of species of, in different types of sediment - 160
reference to, of Otusia sandbergi discussed.............- 770
stratigraphic position mentioned...................... 320
type species ‘‘ Orthis sandbergi”............ 769
Ulrich on spondylium.--..-.-............. 308
SCA0ENgT ESCO DE Cees ee eee eee eee ae = 769
compared with Finkelnburgia finkelnburgi...........- 794
ORIG OHTAVE DS sca somcassasosaccdbdasans=nodese 770

general geographic and stratigraphic distribution
LEIS EMC 2 5c cansendoesactiedbsasesangsseaceednecne 108

type specimen not figured.

@ichensis,desChi bed sas= sane eee eeee eee eee eee eee eee 770

general geographic and stratigraphic distribution
tabulated ey Sec ce sence saeco soon see renee eer ee 108
type specimen figured.........--...... Pl. LXXXIX, fig. 3

Ouray County, Colorado, localities in............-.....-..-- 335a, 360b

Outside lateral muscle scars, shown in figure.................. es srs

Outside and middle lateral (protractor) muscles, defined.......... 294

ovalis, see Acrotreta.
Ovando quadrangle, Montana, localities in.......... 4q, 4q’, 4v, 4w, 8j

Opies, Shona, Woea thay thi 6 pen sseonccsoeooacoseousseossoobonene 350a
Owen, D. D., bibliographic references -- oe 22
Speciesmamedifornaaanccs ms cteceiseceensetcet eC eee cee acee 523

weni, see Lingulelia.

860 ; CAMBRIAN BRACHIOPODA. \

Owl Creek Mountains, Wyoming, locality in.-...........-------. 302p | Passage beds—Continued.
Oxna (Oksna), Norway, locality at...---..----2---22--22--2---+- 323u Finland, generalized section, listing included and corre-
pacifica, see A crotreta. i lated species and localities ....................2-.-------- 144.
Pack, F. J., bibliographic reference.....................-....------ 22 genera in, Tisted ysis sc Neer haha ves baa ee grants Waa nN 110-111
Packsaddle Mountain, Texas, localities on.........-.-- 68, 68e, 68y, 68z Nevada, detailed section, listing species and localities. . _... 139
Paget limestone (Upper Cambrian), detailed section listing in- Norway, generalized section, listing included and correlated
cluded species and localities ............-----..------------ 125 Species;an Calo ce SGT eS Eee ee eee ee 144
pagoda, see Hoorthis. Russia, generalized section, listing species and localities.... 143
Pagoda Hill, near Tsinan, China, locality at. C56 species in, listed 98-109
Pahrump Valley, Nevada, locality near.....-..-......--..-...-.- in Sweden, generalized section, listing included and correlated
(Palzxobolus), see Obolus (Palxobolus). species/andilocalities s= == seen sea] sae pee eeeee a eee ee eeen 144
“ Palzxobolus bretonensis,” type of Obolus (Palzobolus)....-.----- 378,426 | Pass Creek, Montana, localities on and near. -150a, 152a, 152b, 153,153a,154
palliatus, see Obolus. Patella rivulosa, typelol Phithedra. 2-2 sees ae eee nesses eee 724
Palms, Esthonia, Russia, localities near.......-.....-- 396j, 396m, 396p- | “‘ Paterina,”’ Rustella compared with Beecher’s ideal. a eee FAB 98
pandemia, see Obolus. type of Beecher’s genus discussed........... 334, 344, 349
Pander, C. H., bibliographic references....................---.--- 22 sediasia;subeenush esses eee ates eee ene e tee eee eee ace 336, 344
SPECIES ANAC Ci Oe ea ee eee eel eee aia 408,652 | (Paterina), see Micromitra (Paterina).
panderi, see Acrothele and Obolus. Paterinid ce; classic aio Ole =e see esse eee eee eee eee 321, 322.
pannula, see Micromitra (Iphidella). distribution in Cambrian strata..............-..--.----.--- 316
pannula maladensis, see Micromitra (Iphidella). genera and species referred to, described...............-.- 329-369
pannula ophirensis, see Micromitra (Iphidelia). general stratigraphic distribution and number of Cambrian
Panther Creek, Yellowstone National Park, Wyoming, locality genera and species of..........--..-------- y 112
MOAT os east aster teeing oe Gaeee seise ae Seseccmemest 302h number of Cambrian genera and species of. - 112
papias, see Hoorthis. number of genera and species in monograph 113
Parabolina zone, in generalized section for Cape Breton, listing in- number of Ordovician genera and speciesin monograph.... 113
cluded and correlated species and localities............... 131 vascular markings discussed -.......-.....---.---.-.---.---- 311
MENGONER: asce sees e eee aoe Se eR Ee ais oe eee Sei 487 | Patterson Canyon, Schell Creek Range, Nevada, localityim....... 8e
Paradise Dry Canyon, Cache County, Utah, localities in......... 31z, | Pavant Mountains, Utah, localities in -....................... 331, 33n
32d, 32e, 55t | Pawlowsk, near St. Petersburg, Russia, localities at........ 336w, 395w
Paradorides, association mentioned...........-- 485,555,706, 730,773,809 | Peak, Tennessee, locality mear..............-...........-.-.....-. 7d.
‘Panadonides beds, mentioneds == es -ms- aes ee eee ee eae 499 | Peale, A. C., bibliographic reference Bt 22
‘Ponadoridesiauna mentioned ess) seeer esses eases seas eee 500 Species Mam ed fOr. ee <n otjsewiee seeminiee eee ee eee eee 339

Paradoxides series, mentioned 516
Paradorides zone (Middle Cambrian), localitiesand speciesin,listed. 124

Vocalities meee se eer] Aah eeeer 2a, 21, 2m, 2s, at, 3, 3b, 3i, 6g, 314,

320b, 345, 345a, 345d, 345e, 350

mentioned aeeeeee == s- eee Eeee eee ee ere 360, 555, 687, 707, 708, 773, 785
Paradoxides bohemicus, association mentioned 531

mds, association mentioned tases. s-s=eeee= eee saanee sen e 498
davidis zone (Middle Cambrian), in generalized section for
Sweden, Denmark, Finland, and Norway, listing

species and! localities -....-..-.---.-..--------=----- 146
localities in.......-.- - 16k, 161

° mentioned ese. 5oae-eascecceeasesaccces sco sekesuesos 515
forchhammeri beds, mentioned...................-........-. 663

forchhammeri zone (Middle Cambrian), in generalized seck
tion for Sweden, Denmark, Finland, and Norway,
listing species and localities _..-......-......-...... 145
localities ines-sssse sense ceee 8w, 16h, 16j, 310i, 3101, 320g,
320m, 320n, 320p, 320q, 320v,
320y, 320z, 321q, 3211, 334, 334h

mentionedk a esesres sen eerae Sosa eee serice = 578, 642,709, 712
See also Forchhammeri zone.
hicks?, association mentioned ........-..--..-..--.---------. 498
elandicus, association mentioned ..........-..........------ 712

e@landicus zone (Middle Cambrian), in generalized section for
Sweden, Denmark, Finland, and Norway, listing

SPeCles|AN GN OCAlLICS eens eee sane ees ae eae 146
localitiesiiisere seer eee eeee ssa 8z, 310¢, 310p, 3201, 323b
ef. tessini, association mentioned .._.......-..-........-.-.. 531

tessini zone (Middle Cambrian), in generalized section for
Sweden, Denmark, Finland, and Norway, listing

Species/an alo cal bles oe ames eee ne ne eee eee eee 146
localities in .............- 310m, 3100, 320d, 320h, 3200, 334c
Parara, Yorke Peninsula, South Australia, locality at............ 3lba

Parastrophia, reference to, of Hwenella abnormis discussed
iParietalibandrd chime deter memeer enema neers ete ert eae

Syayoyyaal Thali fabbile) 2) coc coeaconerineocseceon sae onMEoreSeseesS
Paris, Idaho, locality near...
Park County, Montana, localities in

Parker’s quarry, near Georgia, Vermont, localities at and near.... 25,
28a, 319g, 319j, 319k, 319m
Parks, W. A., acknowledgments..............-.--......--------- 12

parvula, see Acrotreta.
parvus, see Dicellomus and Obolus.

Passage beds, Bohemia, localities and species in, listed........... 124
Denmark, generalized section, listing included and correlated
Speciesyandslocalitieseres eer emer ae mee eae eee eae 144

familiespim Ste diapers eee ee eeeeeetiaeistelsttateeteteeiee se aie 112

pealei, see Micromitra.
pectenoides, see Dicellomus.

peculiaris, see Kutorgina.

Pedicle, defined): 22-524 cdi ins bel ceeige AU aac eee eee SEE
Pedicle aperture, discussed
Pedicle furrow, defined...

showin fleures: yocstests-ee se os se tee eo ae eee 374
iRediclejproove, Genin igsee ear eee eee eee ee ees 294
Pedicle muscles, defined............------ 294
Pedicle muscle scar, shown in figure 374
Pedicle opening, defined.............-.-..-- 295

developmentio fees seer er ER ae eee e aera eee 306

GISCUSS€ C= eeae eet a= eee ere eee ae eee 318
Pedicle tube, defined. 295

development of 314

discussed! each Rue UeL ete lpene: Auli He ete ee abe 314-315
pelias, see Obolus meconnelli.
pellico, see Nisusia (Jamesella).

Peltier, Tennessee, locality mear............-..--.....--.-----.--- 374e

Peltura fauna, C3b (Upper Cambrian), locality in..-.............. 325

Peltura zone, in generalized section for Cape Breton, listing in-
cluded and correlated species and localities.. ........... = TBH

Pembrokeshire, South Wales, locality in
Penmain Pool, North Wales, locality at
Penmorfa, North Wales, locality at...--............--------.---.

Penmorfa Church, North Wales, locality at............-..---...- 318t
Pennsylvania, Cambrian species of, listed................------ 114-119
localities in... --- 8q, 12v, 48d, 49, 49a-f, 49w, 50, 50a, 346, 346a-c
note on stratigraphic position of localitiesin..........-. -.. 143
Penrhyn quarries, Middle Granville, New York, locality at........ 22a
Pentameracea, classification of.......-....-...---.-------------- 321, 326
cruraliumimenthioned ieee f= se see eee eee eee esa eeeas 309
distribution in Cambrian strata........-....-...----------- 316
genera and species referred to, described .............-.-.- 796-810
microscopic structure of Cambrian and later, discussed - -..- 300
Pentamerid#, Ulrich on spondylium...................-.-------- 308
Pentamerus, compared with Obolella.....-. 597
Ulrich on spondylium............... 308
Pen-y-Bryn, North Wales, locality at... - 366h
Pen-y-pleidiau, South Wales, localities at...............-.--- 318g, 318]
Pepin, see Lake Pepin.
Pepper Mountains, Poland, locality in...............--.---.----- 368

perattenuata, see Lingulella.

perfectus, see Obolus ( Fordinia).

Peripheral vascular canals, shown in figure........-.-....------.- 374
perpasta, see Nisusia (Jamesella).

perpasta macra, see Nisusia (Jamesella).

Ee

en

INDEX.

~perpasta subquadrata, see Nisusia (Jameselia).
perugata, see Kutorgina.

etersony Utah localityemean= sce. 22 ae one eae aeeneeeeecices 329¢

Pewardine, England, locality at.........-..-. 2.22 ...eeeeee eee eee 304k

phaon, see Lingulella.

pheres, see Obolus.

JAIGG, COSGHI Gl ~ Cone ctlenouosoanmosesnasaebohconuasddscecasce 724
andina learea tus CUSSCC sree erEesreE tener aeeee eee nneine 305
classification of -- 321,325
evolution of. -- 317
general geographic and stratigraphic distribution of

ae species relerred Ones sae ee eee ener eee eee 107
general stratigraphic distribution and number of Cam-
brian species and varieties of 111

, muscle scars, not shown in....-.......... 313
number of species of, in different types of sediment... 160
occurrence in Cambrian, discussed..........-.------- 319
type species ‘‘ Patella rivulosa”’?...........-...-----... 724

columbiana, described 724
general geographic and stratigraphic distribution

tbe WL abe Saree ee ate penis yas ciclo ae eeinne eee ele 107

type specimen figured. . Pl. LXXXI, fig. 10

Phillips, J., bibliographic reference 22

species named for..............-.---- 352

Phillipsburgh, Quebec, localities at...............-.-..------ 392i, 392m.

Phillipsburgh formation (Lower Ordovician), mentioned...--.... 319£

Phillipsburg quadrangle, Montana, localities in. ....-.-
phillipsi, see Micromitra (Paterina).

302q, 302r, 340e

Pholidops implicata, compared with Bicia whiteavesi.......-.-.--- 568
Phyllograptus slate (Passage beds), in generalized section for
Sweden, Denmark, Finland, and Norway, listing species
NGMOCAIPLeS is sins syntactic eee ect ee coe eee 144
JOcAIbIeS TINS ss eh soe oe sas sc deo ecac eae te sasecee= eens 323, 323i
‘Pike View, near Colorado Springs, Colorado, locality near........ 360d.
-pileolus, see Orbiculoidea.
Pilot Knob, Wisconsin, locality near.............---.------------ 99a

Pinal County, Arizona, locality in
Pinnacle Peak, Eureka district, Nevada, locality near...........- 65
Pioche, Nevada, localities near..........---- 7k, 31, 3la, 31u, 333a, 333b
Pioche formation (Lower Cambrian), in detailed section in House
Range, Utah, listing included, and correlated species and

I@@AIAES 55 acco ossenocnosSabsseaasecsesscrose sseereose 158
I@BEWITIES Th eiboecocobeneosodooosescaosno shee 412, 31a, 33i, 52%
species and localities in Nevada correlated with............ 140

Plezsiomys ? deflecta group, classification of, by Ulrich............ 308
Planilimbata limestone, in generalized section for Sweden, Den-
mark, Finland, and Norway, listing species and localities. 144

See also Megalaspis planilimbata zone.
IT, CAINE soo ee Seoanaesoendodascnecoco spananecseaaceans
discussed.....-.--
Hall and Clarke on.
Platform-bearing brachiopods, development of. .
Platystrophia, classification of, by Ulrich.........-.-...-.-...----
compared with Hoorthis remnicha.........------------------
no Cambrian representatives. -.-....-.-.-
Plectorthis, classification of, by Ulrich
discussed iemicn meee cree

muscle scars of, discussed by Ulrich..-...........---- 308
no Cambrian representatives.........---------------- 320
reference to, of Protorthis hunnebergensis discussed.... 741

See also Orthis (Plectorthis).
plicatella, shell section figured ..............-...--

whitfieldi, compared with Billingsella by Ulrich........-.-- 308
discussediby7Uilnich =o. - eee eee see se =n e eeeeeee 308
muscle scars of, discussed by Ulrich... 308
TEleounaeos les, Clsdineel eos cS sae scos os sosos Tose saseseuonScesse pay 0295
shown in figure. ...-....-.-.........-. EdogasSuAceScecuogeES 374
WEESIIS OF Sotohy a0 pial yh on Gagne coon suSocHoosabo=ceneacrS 374
plicatella, see Billingsella.
Poddrus, Esthonia, Russia, locality near.........-...-..--------- 337e
Podolova (Putaloya?), St. Petersburg, Russia, locality at ........ 366a
pogonipensis, see Lingulella.
Pogonip limestone, detailed section, listing included and corre-
latedsspeciesandilocalitiests- mer ssee-seeree eee eee ee 139
mentioned 517, 688, 689, 777
Pogonip limestone (Lower Ordovician), localities in.............- 63,

201a, 202, 203, 204, 209, 214a, 214b, 221
Pogonip limestone (Passage beds), localities in........... 201, 203a, 211

Point Amour, Labrador, locality at.......--.-------------------- 3921
Point Levis, Quebec, localities at. - .. 319, 319a, 319d, 319i, 392]
Poland, Cambrian species of, listed. ......-..-------------- ----- 120-121
Pole Creek, Madison County, Montana, locality on............-.. 149a
politus, see Dicellomus.

Polk County, Tennessee, locality in........:..------------------- 128a

Polk County, Wisconsin, localities in......-.---.---------------- 78,
78b, 78c, 78s, 82, 82s, 328b, 328e, 328f, 328h, 328m, 328n
304b

Polyphyma zone (Upper Cambrian), locality in.........------.--.
Polyiechia, compared with Clarkella....-...-.-------------------
“montanensis,” type of Clarkella
Pompeckj, J. F., acknowledgments........-..--..----------------
bibliographic references. .--.-2-.---.2-----------e----------
Pont Nant-y-Ladron, Wales, localities at..
Popes Peak, Alberta, locality near..........--..-..--------------
Popo Agie Canyon, see Middle Popo Agie Canyon.
Popowka, St. Petersburg, Russia, localities at-......-.-

336, 336y, 337m

Porters Brook, New Brunswick, localities on ........-..---- 3011, 301m
Porthclais Harbor, Wales, localities at - 366b, 366c
Port Henry, New York, localities near..-.......-...-..-------- 136, 367g

Porth-y-rhaw, South Wales, localities at....,-......--.--.-.- 318d, 318¢
Portland (St. John), New Brunswick, localities at.. 301g, 301w, 308h, 308i
Portland Creek, Newfoundland, locality near..... 314d
Portmadoc, North Wales, localities at and near
Porto Canal Grande, see Canal Grande.

Portugal, Cambrian species of, listed............-....-.---.---- 120-121

locality,ins > “sen vaseaue anna coe ence eeeiaceetee SOO
Posen; Germany, localittyineesssee-eeese scence erseccaes 386h
Posterior region, defined....-....- BooonabesaasebE > AD)
Post Oak Springs, Tennessee, localities near........--..........-- 11, 13
Potosi, Missouri, localities near..................-..---------- lle, 369b
“Potsdam formation,” mentioned.............-..-.-. --- 524
Potsdam sandstone (Upper Cambrian), localities in _- - 110,

111, 136, 185, 185a, 338j, 338r—u, 338w, 392

“Potsdam” strata, mentioned....-.-...-----.......-.-..---..--- 527
Poughkeepsie, New York, Lingulella (Lingulepis) acuminata at,
CISCUSSE Cass Mee PM etter nak eee a neh CINE sm ema a eee 548

localities!mear 25.25. -eeeersecies s oie nee see ce eee 108, 367e, 367j

Poultney River, New York, locality on ae 34

Powder Riven, Wyoming locality OW sces seems see ssh eee ose 302x

Powell County, Montana, localities in-. --- 3j, 4q, 4q’, 4v, 4w, 5j, 8j

Powells Plateau, Arizona, locality near..............-.--..-..---- 74d

Prairie du Sac, Wisconsin, localities at....... Soe eee eee i 85, 85s

Praschno Augezd, Bohemia, locality at...............:..--.-----. 345¢

Prestorpyoweden) localityabs epee eee cer eseeree aetna eeeeeonne 390k

pretiosa, see Acrothele and Mickwitzia.

prima, see Acrothele, Acrothyra signata, and Lingulella.

prima costata, see Acrothcle.

primezova, see Acrothele, Acrotreta, and Lingulella.

primordialis, see Eoorthis and Syntrophia.

primordialis argia, see Syntrophia.

Princeton, Montana ocalityaneataas sseenas == see eee aes ae seen 302r

Pringle; lu. M., species named) forces sees eee ee nee eee ee eneaesees 409

prindlei, see Obolus.

Printuf House, Gadsden, Alabama, locality near................. 138

priscus, see Schizambon.

pristinus, see Trematobolus.

proavia, see Acrothyra.

Productidz, cardinal process discussed ...................-..-..- 306
cruralium mentioned................-...--. 309

“ Productus limestone,’’ mentioned . - 511

proles, see Acrothele.

prolificus, see Dicellomus.

Promontory Point, Utah, locality mear.........-................- 300

prospectensis, see Micromitra (Paterina).

Prospect Mountain, Eureka district, Nevada, localities on.... 52, 54, 55
Prospect Mountain limestone= Eldorado limestone.

Prospect Mountain quartzite, in detailed section in Eureka district,

in detailed section in House Range, Utah.....
Proterpainm)d efinedpees esses seen ee sess eee
“ Protolenus beds,’’ mentioned .....-....1--.-------
ECP TOLOleTmUSHalina 22 MeTItOTIC Meese memes eeee eee ereee aeeeeneerce se

Protolenus zone, generalized section of beds referred to.........- 132-133
1b1 (Middle Cambrian), localities in ..--......-- 2f, 2g, 301i, 308e?
1b2 (Middle Cambrian), localities in -.-......---.-.......- 2h, 301

1b3 (Middle Cambrian), localities in --.-..-.-.. 2i, 2k, 301la, 308g?
1b5 (Middle Cambrian), localities in.......-.-.--- 301b, 301d, 301f

862 CAMBRIAN BRACHIOPODA.

Protorthis, described..........-----+--+---++---2 2-22-52 2e errr eee 738
cardinal process discussed ........-------------------- 306
classification of. 321,325
compared with Protorthis (Loperia) dugaldensis. ...-- 744,745
dental plates discussed .....--..----------------- so lil
evolution discussed): <--2 <= see. ae me lel 320
EVOLUTONIOL = -\s sees aaa eee eee 317
general geographic and stratigraphic distribution of

the species referred to......-.--.------------------- 107
general stratigraphic distribution and number of Cam-
brian species and varieties of.......-.------------- 111
muscle sears discussed.....-.--.----------------- so IK
number of species of, in different types ofsediment-.. 160
presence at Hastings Cove, mentioned.......-.--...-- 779
reference to, of Nisusia (Jamesella) spencei discussed. 737
reference to, of Protorthis hunnebergensis discussed.... 741
reference to, of Protorthis latowrensis discussed . - 742
spondylium discussed.........---------------- 307
stratigraphic position mentioned-..........---------- 320
Ulrich on spondylium in.......-..-..---------------- 308
vascular markings not preserved........ 311
billingsi, described. .-.-...- 739
compared with Protorthis latowrensis.. . - 742
Protorthis quacoensis. - 743
JEROFOMINIS QUO ls om == wccesoecoeosso0ss=ce0s2ene= 743
general geographic and stratigraphic distribution tabu-
IRIE 22d daecesseapacoa=seccbecccnboesooecencoaacs 107
type specimen not figured.
helena, described ...-...--------------------++-------------- 740
general geographic and stratigraphic distribution tabu-
IHG ce acco ses osemsdscoscoesocobeadhsosstocscoases

type specimen figured
? humnebergensis, described... ....---------------------------
general geographic and stratigraphic distribution tabu-

107
type specimen figured . Pl. XCV, fig. 5a
levis, described TAL
general geographic and stratigraphic distribution tabu-
IB oo se gcosotcacosconscosnescesesnseossecsesssess 107
type specimen figured............--- Pl. XCIX, figs. 6, 6a-b
latowrensis, described. 741
compared with Protorthis helena.....-..-------------- 740
general geographic and stratigraphic distribution tabu-
IDC. soc censaseopecesssospousoD oud IH edEosSORDOsO=00 107
type specimen not figured.
quacoensis, described. .-...---..-----------+-+--++22--7----- 742
compared with Protorthis sp. undt--..--------------- 744
general geographic and stratigraphic distribution tabu-
TPUOEl oe ssacton se oscesc ooepncoumseaacsouScasesEseoneS 107
muscle scars discussed.....--.------------------------ 313
type specimen figured. . Pl. XCIX, fig. 2b
wingi, described........-----------------++-+++++2+++++7->-- 743
general geographic and stratigraphic distribution tabu-
Nated ese eee seen see eee asia 107
type specimen figured . Pl. XCIII, fig. 5a
sp. undt., described.......--------------------++++++++------ 743
general geographic and stratigraphic distribution tabu-
IAA eo ac cee once asoagosb sods sea pasOS SRS UEEOSOGS> 107
type specimen not figured.

Protorthis (Loperia), described. .
classification of. -
evolution of
general geographic and stratigraphic amiiion of

the species referred to..-.....-.--..---------------- 107

general stratigraphic distribution and number of Cam-
brian species and varieties of.....-...--.-...---.--- 111
number of species of, in different types of sediment .. 160
stratigraphic position mentioned.........-.---------- 320
type species Protorthis (Loperia) dugaldensis - 744
dugaldensis, described .....---.--------------- 744
compared with Dinorthis......------------- 320

general geographic and stratigraphic distribution
tabulated): << <2 oe e en ne en nn nnn 107
type of Protorthis (Loperia)..-.....------------------- 744
type specimen figured...-...-..-.-- . Pl. XCIX, fig. 5
Protosiphon, discussed ......------------------- .-- 616,619, 620
Protractor muscles, defined........-.---------------------------- 295
Protremata, articulating processes discussed..----.-----.--------- 307

cardinal area discussed.......-..--------------------------- 305

Protremata—Continued.

classification of. 321, 325:
defined!) 3s = ces ahsee seesaw slsee wale eis ok Bere aoe eee 295.
dental platesidiscussed eee esee sissies eee se eee 310-311
distribution in Cambrian strata...........-.--------------- 316.
evolution of genera of, discussed. -- - 319-320
holoperipheral growth of deltidium in _.................... 306
miuscle\scars) discussed ess=sa- sess ssa eeee eee eee e eee 313.
pedicle opening absent in all Cambrian genera except Bil-
lingsellas. soe se ine ose ae Se ee eee

pedicle tube discussed
pseudospondylium in

Spondylnimydiscussed see esse == se eee eee 307-308
surface ornamentation discussed ..........-------.- Bee echt
vascular markings discussed.............--.---.--.------ 311-312"
Protremata (Ordovician) shell structure compared with that of
Cambrian eoorthoids and Billingsellidee..............--.. 300
Te ToH Ao}, WWhtsor, Wore BMPS = = 5 352 Sos coos sboacetossseesoouwaeses tw
Prussia, Cambrian species of, listed.........--.--...--.-------- 120-121
See also East and West Prussia.
Prussian Holland, Hast Prussia, locality near.............-..-.-- 386a-
Pseudo-area: defined sya c ear aemncene eee ese eeanee rer

Pseudochilidium, defined:.----.--..-------.-----.-.-..-......--.

GUECERE Gl = = we ghoeaseecousecascesesesseozce
Pseudopedicle groove, defined -
Pseudospondylium, defined...........-.-.-..-.------------------
IPskow, eRw1SSia)) Locallitiyy 10 eee te ae ae ee eee er

Ptychoparia, association mentioned a 349°
mentioned see sesse sce eee eee 501

kingi, association mentioned 658.
minuta, association mentioned ......-.-..------------------ 527
robbi, association mentioned......-..---.--..--.------------ 498
variolaris, association mentioned.....-..-..--.----.-------- 498,

pulchra, see Botsfordia.

Pulkowa, near St. Petersburg, Russia, localities at.........-. 3360, 3961

Pulkowa Brook, near St. Petersburg, Russia, locality on......... 395y

Pulpit Rock, Nahant, Massachusetts, locality at...-..-.........- 326¢.

pumila, see Lingulella (Lingulepis).

Pumpelly, Raphael, species named for_..........--.-----.-.----- 761

pumpellyi, see Billingsella.

punctata, see Lingulelia.

Punta Pintau, Sardinia, localities at...-....---.----..- 354b, 354c, 354£

pusilla, see Micromitra. J

Putalova, see Podolova.

puteis, see Acrothele avia. |

Puxley Park Lane, Atherstone, England, locality on......-.--... 304);

pygmea, see Lingulella (Lingulepis).

pyxidicula, see Acrotreta.

quacoensis, see Protorthis.

quadrilateralis, see Lingulella.

quadrilineata, see Acrothele.

Quebec, Cambrian species of, listed.......---------------------= 114-119»
localities near.......---------.-- . 56a, 56b, 319c, 319h, 3191,

Quebec (Province), Canada, localities in... 2n-p, 2r, 220a, 319, 319a-d,

319i, 319n-p?, 319t, 319u, 3922, 392g-j, 392m, 392n?

note on stratigraphic position of localities in........-...-..- 143.

“Quebec group” (Lower Ordovician), localities in. - .. 314d, 392j

mentioned. ...-.--------2---- 22 ene enn nnn 517
See also Division P of Billings.

Quebecia, described.......-.---------+-+------------2222--0 220 2-- 609°
cardinal area discussed. E soo |) BOS
classification of....--..---------------- -.. 821,324
compared with Acrotreta 611

OW lis ¢ ppoadaotaansneccospeetdeesacesasnscese 611
Wath coc anoacceecanseeeeseoseceaseasessaceoS 611
evolution discussed. .-..-.-.------------ 319°
EVOLUPLON) Ole ee eee eee ee tate ei 317
general geographic and siieatcanaTante distribution of
the species referred to....---.----------------+--+-- 104
general stratigraphic distribution and number of Cam-
prian species and varieties of-..-.------------------ 110
number of species of, in different types ofsediment... 160
shell substance. -..-..----------------------+---------=- 297
stratigraphic position mentioned 318-
type species ‘‘ Obolella circe”’.....--------------------- 610”

——_

INDEX.

QmebectaicincendescMibedee sere ses -e wee ioe i se ee ee 610
general geographic and stratigraphic distribution
TA DWIETICE|S 5 sad eo so aces COBRA BOR ose SRaseeeeasabecss 104
type specimen not figured.
Queens Canyon, near Manitou, Colorado, locality in.............. 360f
Quenstedt, F. A. von, bibliographic references...............-...- 22
SAMO byga atin COMOLe tersietcerelielaicleje cine visieisieis weiss avis ee eee 385
quenstedti, see Obolus apollinis.
Quinn Canyon Range, Nevada, locality in.............-......--- vA
Rabenberg, Bohemia, locality at.................-..----.-------- 303E
radula, see Lingulella. A
Rafinesquina, reference to, of Hoorthis atava discussed .........--..- 774
reference to, of Protorthis hunnebergensis discussed........--- 741
Rafinesquine, classification of..........-.......-.-------------- 321, 326
genera and species referred to, described .......-..-.--...- 795-796
Raggedstone Hill, Malvern Hills, England, locality at............ 304c
Rainbow Valley, House Range, Utah, localities near... - - llu, 1l4v

Ramsey Island, St. Davids, South Wales, locality on.........-..- 318w
randomensis, see Lingulella.
Random Island, Trinity Bay, Newfoundland, localities on... Gi, 6s, 6y
Ransome, F. L., bibliographic reference. .....-..........-...--..-- 22
rara, see Acrothele and Nisusia.
Ratcliffs Millstream, St. John County, New Brunswick, localities

ON aedsscsedopedbdaoc soe asacanbosossouscsesabecsqoass 301j, 301z
Rattvik, Sweden, locality near- - . sae 9e
Rawlins, Wyoming, locality near. . ..--. 340c
Reads Landing, Lake Pepin, Minnesota, localities at.. 97, 97x, S97x, 339¢
Reagan sandstone (Upper Cambrian), detailed section, listing in-

cluded and correlated species and localities. ............... 142
Dicellomus politus from, discussed ......-....-.-.-..-------- 577
ISSN TICS Ml -eacsa essen cescoousbeoseaesoe 9p—x, 12k, 12n, 12p, 14q
Rectostriatz, group including Nisusia ? vaticina.......-...--.-....- 730
recurva, see Volborthia. '
Red Canyon Creek, Black Hills, South Dakota, locality on....... 355
Red Cedar River, Wisconsin, locality on................ 2184
Redlich, K. A., bibliographic reference..................-...---.-- 22
MUONS MACE Ps So sseeoabeoscobsonbasenssHsescoodceas 663
(Redlichella), see Acrothele (Redlichella).
Redlichia, association mentioned................--..-------.------ 589
Redlichia noetlingi, association mentioned...............-..-. oo BBY)
Redrock Point, Conception Bay, Newfoundland, locality on..... 5t
Redwater Canyon, Black Hills, South Dakota, locality on........ 355
Red Wing, Minnesota, localities near................-.... . 86a, 113
Redwood, New York, locality near.................- .. 185
Reedsburg, Wisconsin, locality near..............-.-..-------.-.- 80a

refulgens, see Obolus.
Remelé, Adolf, bibliographic reference.............-..---.----- ne 22
remnicha, see Eoorthis.
remnicha sulcata, see Hoorthis.
remnicha texana, see Eoorthis.
remnicha winfieldensis, see Eoorthis.
Rensselaer County, New York, localities in..............-..--.. 2b, 2d,
27, 27a, 29a, 44a, 72, 72a, 338, 338k, 338n, 338q, 338y, 367, 367b, 367i
Resting (Freshwater) Springs, Inyo County, California, localities
MEAD eases Rey ett tetera niot fe tsietaretate ietat arate oteleteietatleveicls 141, 14n-p
Retractor muscles, defined........-......-..--------------------- 295
retroflexa, see Billingsella.
Reyal, Esthonia, Russia, localities at.......---...--...----------- 336e,
336d, 336f, 336i, 336v, 337b, 337h, 396d, 396g, 396q, 396r—t, 396y
localities east, south, and west of.........-.-.-.--- 9d, 336b, 336h,
336m, 336t, 337, 337a, 337c-e, 3371, 395, 395a, 395c-e, 395g, 395h,
395j-n, 395p-v, 395x, 396, 396a—c, 396h, 396i, 396n, 396u, 396x
rhea, see Obolus.

Rhea Springs, Tennessee, locality near.................---....-.- 13b
Rheider Waterfall Valley, North Wales, locality in.......- BB oes 318¢
Rhinobolus, Hall and Clarke on development of 309

ei tormin Waal 55-2 seco oo Sebo soso cosassosoosone 309
Rhipidomelia, classification of, by Ulrich ..........---.--.---.-.--- 308

muscle scars of, discussed by Ulrich..............-..----...- 308
Aviat hymen ales slocalitysatecers sss seeeeeeeceeeee ase nes ste ce 318v
Rhode Island, Cambrian species of, listed... . 114-119

Nocalitiesmeses semcecmia oe sono stewce cise eee 343, 343a, 348b

Rhynchotrema capax, compared with Keyserlingia buchi....--..---- 630
Richmond mine, Eureka district, Nevada, localities at.. E 57, 60
Richthofen, Ferdinand von, species named for....-........-..-..- 762
richthofeni, see Billingsella.

Riders Mills, New York, locality near............-..------.------ 32a

Rimouski County, Quebec, localities in...-.....-...--- 20, 2p, 2r, 319b
Ringsaker, Norway, localities in........... . 8y, 323b, 324, 324d
River Junction, Minnesota, locality at................---.----.-.-

863

Roane County, Tennessee, localities in...........----------- 11, 18, 13b

Roan iron mine, Bartow County, Georgia, locality at 59m
Roan Mountain quadrangle, Tennessee, localities in-. - 22, 374¢
Robert, J. Alfred, species named for.........----..---------------- 558
roberti, see Lingulella (Lingulepis).
robusta, see Lingulella (Lingulepis) gregwa.
Rocca al Mare, Esthonia, Russia, locality at........--.----------- 396
Roche a Cris bluff, Adams County, Wisconsin, locality at.......... 328k
Rockbridge County, Virginia, localities in........------------- 47a, 92b
Rock Canyon, near Provo, Utah, locality in.....-.-.--.-.-------- iw
Rock Creek, Granite County, Montana, locality on.....---..------ 302q
Rock Hill schoolhouse, near North Greenwich, New York, locali-
ties near t 33, 338¢

Rocky Gap, Virginia, locality mear............-..---------------- 4th
Rocky Mountain province, Cambrian speciesin, listed...--.....- 114-119
Roemer, F., bibliographic references. -- - 23
Rogers, W. B., bibliographic references - 23

species named for..... ------.---- 87-2. 465

rogersi, see Obolus ( Westonia).

Rogersville, Tennessee, localities near....... 9, 9a, 12q, 101, 101a, 101b,
102, 102c, 103, 103a, 103b, 104, 121, 121a, 122, 123, 124, 124a, 374b

Rogersville shale (Middle Cambrian), in generalized section for
Tennessee, Georgia, and Alabama, listing species and locali-

[HES 5 soaconscanesoaseadsenao = Sco TooSeSSsDSseSSSrecoosesS 147
Tocalitiesii sees seen eee eee 101, 101a, 101b, 102, 121, 331
Rohilla, Oeland Island, Sweden, locality near .....-..----..----- 390d
Rokitzan, Bohemia, locality near..-......--.---.---------------- 303b

rokitzanensis, see Obolus.

Rome, Georgia, localities near...-..--.-.---.----- 18c, 14, 96, 96b, 138a

Rome formation (Middle Cambrian), in generalized section for
Tennessee, Georgia,and Alabama, listingspeciesand locali-

HOCATMES WA = 350 cscs seoososcesesenoeeedcesesocesesssoorene 10a,

10b, 11,13, 13b, 13c, 14, 14a, 103, 103a, 103b, 106, 107b, 138a

Rome, (‘‘Montevallo”) shale (Lower Cambrian), localities in. 17b, 56¢
Rominger, C., bibliographicreference........--...---------------- 23

species named for.....-------------------------------+----- 763
romingeri, see Billingsella.
Rosses Bridge, near Essex, New York, locality at -.-..-....------ 367h
Ross-shire, Scotland, localities in-.----------.--------------- 316c, 316d
3096

RéstAnga, Sweden, locality neaw.....-..--.--.-------------------
Rostock, Germany, locality near 2
Rotherwood, Tennessee, locality near..-..--..------.------------

374d
rotunda, see Lingulella.
rotundata, see Syntrophia.
rotundatus, see Obolus.
Round Top Mountain, Eureka district, Nevada, locality on ...... 205
Rowe, R. B.,speciesmamed for....-..----.----------------------- 558
rowei, see Lingulella (Linguvepis).
Ruby Hill, Eureka district, Nevada, localities on--.....-...-.- 57, 57b
rudis, see Acrotreta.
rugatus, see Obolus (Acritis).
rugosa, see Acrotreta ophirensis and Schizopholis.
rugosicostata, see Billingsella exporrecta.

Russelékken, Norway, locality at.............------------------- 323x
Russia, Cambrian species of, listed .....-.---.------------------- 120-121
generalized section of Cambrian and Ordovician in, listing

species and localities ..............-.--.----.----------- 143-144
localitieshinGaseeer cece ee one eee 9d, 311d-f, 311q-t,

31llw-y, 336, 336a-z, 337, 337a—n, 395, 395a-z, 396, 396a-z
species and varieties of Obolws and subgenera recognized by
Mick witziniylisted’s-Aceece meen cteeeeemee sce ereenmectes
See also separate governments.

Rust, William P., genus named for.-..--.--..-..--..---.-.-....-.
TRAM ti, COTTAM NLS m= os sso sodas cceoocososus ssoseccoscosnceoses
attachment of muscles in.

classification of

380

compared with Beecher’s ideal ‘‘ Paterina”’........... 328
CU elo sieacsooduessdooR enon aHeseaa7ecS0Sa0 370
evolution discussed 318
CONTI M Og asaccsaseesagsoeesses 317
general geographic and stratigraphic distribution of
tihejspeciesireferred|ito--=-- sense -e ese ees eo 98
general stratigraphic distribution and number of Cam-
brian species and varieties of.........-...-.-....-.- 110
number of species of, in different types of sediment .. 160
SBI BEES cegoccans=ases2cbsacoséaooseabeseoesns 297
stage, mentioned ieee scar tea. teeters eee eeace oe 305
surface ornamentation discussed . . 301
type species Rustella edsoni..........-.--.------------ 327

864 CAMBRIAN BRACHIOPODA.

Rustella edsoni, described....-.-..-.----------------------------- 327
cardinal area discussed.......-.....-.------ 303
compared with Rustella ? major ..--.------ - 328
confused with Kutorgina cingulata e328
evolution discussed...........-.-..------------ EEEeTOLS
general geographic and stratigraphic distribution tab-
Wate” oe ee es ees see eae aa nea 98
most primitive brachiopod...........-..- . 316,318
muscle scars discussed............-.----- tee, pol?
type species of Rustella 2 327
typeispecimen|figured.-2 ese s---- 4-2 e see oon Pl. I, fig. 1
2 qn foi COOMA. 6s soaconisacosoesceassoesses 555) BP
compared with Obolus by Matthew piste (O28
Rustella edsoni ease B3
generic reference questioned teen) Be
general geographic and stratigraphic distribution tab-
Ulatedin ss majectiese a coscecses seere tee eee res 98
type specimen figured..........--..--.--.- text fig. 19,328
Rustellacea, classification ofes=--2. spe eee eee eee ene eee ees 321,322
distribution in Cambrian strata-..........-.-.--- eos BIS
genera and species referred to, described ....-.-- . 327-369
Rustellide, classification of..........--...-.-.------- . 321,322
distribution in Cambrian strata.-.........-:-..-.---------- 316
genera and species referred to, described...-....-...2-....- 327-328
general stratigraphic distribution and number of Cambrian
genera and species of.........-.----.--------- pel tL.)
number of Cambrian genera and species of. 112
number of genera and species in monograph 113
Rutland, Vermont, localities at and near............-.------ 319w, 319x
Rutland County, Vermont, localities in.................-..- 319w, 319x
Rutledge limestone, in generalized section for Tennessee, Georgia,
andAllabam aera cece en ene eaeemenince tenes Rec cekea ne 147
Sabero, Leon, Spain, locality near .........-....-.--.-.--..-----. 350
sabring, see Acrotreta.
Sachuset Beach, near Newport, Rhode Island, locality on_....... 343b
Safford, J. M., species named for Bo ROR

saffordi, see Wimanella.

Saggad, Esthonia, Russia, locality at.........-......-..----..-.- 396m
sagitialis, see A crotreta.

Sagittalis magna, see Acrotreta.

sagiitalis taconica, see A crotreta.

sagittalis transversa, see Acrotreta.

Saimaki, China, locality at.-----......--.-..----..-......--.--..- 332
St. Albans, Vermont, localities near 16n, 319f, 319s
“St. Albans formation’ (Middle Cambrian), localities in... . . 28a, 319s

St. Charles limestone (Upper Cambrian), in detailed section in
Blacksmith Fork, Utah, listing included and correlated
Speciesjandvlocalitiesstee nose reer ace eens eee se ee 148-149

localities in wee), AY,

5a, 5c, 31m, 31n, 54b-g, 54j, 54t, 54u, 54w, 54x, 55h, 56¢

St. Croix County, Wisconsin, localities in......... 79, 79’, 79b, 79s, 328)
St. Croix Falls, Wisconsin, localities at......-....... 82, 82s, 328e, 328h

St. Croix River, Minnesota, localities on.....-- 97b, 339b, 364a

St. Croix River, Wisconsin, localities on.. 78, 78b, 78s, 82, 82s, 328f, 364a
“St. Croix sandstone,’’ stratigraphic position of localities in

GbIRGUREE SIS 5 5 5 soe Sousda sce sdedo sh dnd abeeosnMOEDEeeaaeeeS 159

“St. Croix sandstone”’ (Middle Cambrian), localities in........... 79x,

831, 84, 84f, 84s, 97b, 328e, 328g, 339e

“St. Croix sandstone’’ (Upper Cambrian), localities in.. 10v, 78, 78a—d,

78s, 79, 79’, 79a, 79b, 79s, 80, 80a, 81, 81b, 810, 82, 82a-c, 82s, 83, 831,

833, 84a, 85, 85a, 85s, 85x, S85x, 85z, 86, 86a, 97, 97a, I7c, 97s, N7x,

S97x, 98, 98a, 98x99, 99a, 100, 100a, 113, 116, 134, 134a, 135, 135b, 135¢,

328, 328a, 328c, 328d, 328i-1, 328n, 328p, 328q, 339b, 339d, 339f-h

St. Davids, South Wales, localities at and near................... 318d,
318g-j, 318n-r, 318w, 366b, 366c

St. Davids Head, South Wales, locality near.-.............--..-.. 366
St. Francois County, Missouri, localities in..................... 11k-m,
369, 369a, 366c, 369¢

St. Fro, Oeland Island, Sweden, locality at..........-....-.----.. 320s
St. John, Orestes, bibliographic reference. ................-.-.--.- 23
St. John, New Brunswick, localities at and near.... 2e, 2s, 2t, 3b, 301le,
301g, 301k, 301n, 301t, 301u, 301w-z, 308, 308a-c, 308f, 308h, 308i

St. John County, New Brunswick, localities in.........-.-- 2e-i, 2k-m,

2s-u, 2x, 3a, 3b, 301, 301a-e, 301g-n, 301s-y, 308, 308a—c, 308e-4

St. John formation (Middle Cambrian), localities in-... 301c, 301j, 301k
St. John River, New Brunswick, locality on 2y, 300, 301f, 308d
St. Lawrence County, New York, locality in.............-..-.-.- 338w
St. Lawrence formation (Upper Cambrian), localities in.. 328b, 339a, 364
Jocalatiesiim mentioned seme eee ete eee seein = 159

St. Lawrence River, Quebec, localities on..-..........----------+ 2n,
56a, 319h, 3191, 319n—p, 319t

St. Martins, New Brunswick, localities in. - 3011, 301m
St. Petersburg, Russia, localities near.............----..--------- 336,

336e, 336k, 336u, 336w, 336x, 336y, 337k, 337m, 395w, 395y, 3961
St. Petersburg (Government), Russia, localities in........- BaMasa eek

336a, 336e, 336g, 336k, 3361, 336n, 3360, 336q, 336r, 336u,
336w-y, 337j, 337k, 337m, 395w, 395y, 395z, 396k, 3961, 396z
St. Piran sandstone (Lower Cambrian), detailed section listing
Speciesiandilocallities) = sss ee--- ese =-=e eee ee ee eee ee eee
locallittysimw2 25 See eee sec eee bee ech eee eee a eee
St. Simon, Province of Quebec, Canada, locality at.
St. Timothy, Quebec, locality at-......-....-.--.-.-..-----
Sta. Benigna, Bohemia, locality at.-................-..-.--------
Salem, New York, localities near
salemensis, see Billingsella.
Saline Valley road, Inyo County, California, localities near.. 53, 312, 312a

Salla, Esthonia, Russia, locality at............-...-..-..-.-.----. 337d.
Sallings Mountain, Virginia, locality on..-...............-.+..-.. 47a,
Salmon River, Cape Breton, locality on. 3n
Salta, Argentina, locality at........- 389
Salta (Province), Argentina, localities in...........-...- 389, 389a, 389d
saltensis, see Hoorthis.
Salter, J. W., bibliographic references. ....\..-..-.---..-------4- 23
Species mamedton’s sous -e nee teeecacses meee eee. ea

Salter, J. W., and Etheridge, R., bibliographic reference. . 23
Salter, J. W., and Hicks, H., bibliographic reference.............. 23
saltert, see Obolus (Broggeria).
Salt Lake City, Utah, localities near...............-..-..-. 30a, 331, 55u
Salt Lake County, Utah, localities in. - 30a, 33i, 55u
Salt Range, India, localities in-.............-...-.-..-- lbr, 357, 357a-d
Saltvik, Aland Island, Finland, locality at................---..-- 3ilx
Sandbersy J.) species mame fon soe es eee eee eee eee eee 770
sandbergi, see Otusia.
Sandby, Sweden, localities at..................----------.--- 309i, 390¢
Sandomierz, Poland, localities near........-..--...---.-.----- 368, 368a
Sand Pass, Fish Spring Range, Utah, locality near......-........ 34h
Sandstone, number of genera and species identified from.......... 1€0
Sandstone and limestone, number of genera and species common

to)both ioe eee Jet ae ecee see sees eee Reet ee eer eE eee ere eee 160
Sandstone and shale, number of genera and species common to

Bothy 22222 5s. Fates aeens emcee Sele ee ee re 160

Sandstone, limestone, and shale, number of genera and species
commoniro/allliGhnee aan esse ee eee eee ene 160
Sandsvir, Norway, localities in 3231, 323r, 323s, 324b, 324c

Sandy Point, Trinity Bay, Newfoundland, locality near.......... . by
San Saba County, Texas, localities in............-..--.-..- 14g, 14i, 353
San Saba River, Texas, locality on.......-........----..--+------ 353
Saratoga County, New York, localities in-......-........--...-. 76, 76a
Saratoga Springs, New York, localities near. - -.- 76, 76a
Sardeson, F., bibliographic reference............-.--..-.-..--.-- 23
Sardinia, Cambrian species of, listed_..............---.-.-.--.-- 120-121
localiiiessin eee ees sees ee at . 354, 354a-f
species of Obolus from, listed .....-.--.-.------------------- 379
sardiniaensis, see Kutorgina.

Sauk County, Wisconsin, localities in..--......-.-...-.---.------ 10v,
80a, 81, 81b, 81o, 85, 85a, 85s, 116, 328, 328q
Sawmill Creek, Meagher County, Montana, localities near_....... bf, 5k
Sbiroy, near Skrej, Bohemia, locality on brook of........--..---- 345
Scapegoat Mountain, Powell County, Montana, localities near.... 3j, 5j
’ Scenidium, compared with Protorthis........-...-.---.----------- 739
Schellbourne, Nevada, localities near_........- Vi, 313a, 313b, 313d, 313f
Schell Creek Range, Nevada, localities in.........-..-.......--.- 7,
8e, 80, 8p, 313a, 313b, 313d, 313f
Schellenberg, near Hof, Bavaria, locality at......-.......-.-.---- 303f
Scluizambon™ describe diese: aes p eee eee eee eee 622
Classifica blonlOleae seen ieee ees eee reece 321, 324
compared with Dearbornia 614
DACA NT ae sae oteancs ssereocaakoe csec once 313, 616
Trematobolus kempanum.....-----.------------ 619
evolution of 317

general geographic and stratigraphic distribution of
the'species referred to-.--------.------------------- 104

general stratigraphic distribution and number of Cam-
brian species and varieties of. 22 ------.8-2--25----= 111
Mentioned: ose sane e cea e eer eee ee eee eee ese 620
number of Ordovician species and varieties of........ 113
number of species of, in different types of sediment... 160
surface ornamentation discussed.............--------- 302

"

INDEX.

Schizambon—Continued.

type species Schizambon typicalis 622
vascular markings discussed 311
CONRAENSTSNCISCUSSCO sae] 2224s oa-e eee ee eee eee 622
? dodgei, discussed..-..-...--- 622

duplicimunatus, GisCussed= 2-2. .2-.---225- 5-22 92 sas eee nan -= 622

PACSHLONUDAGCSCLIDCU re =a -= se jae eei oe oa oe Soe eo aels sae eee 622
general geographic and stratigraphic distribution tabu-
IRWIGG ee oan Caer aco CaSOSSE PR AnSSHermEeppdoaaco amar 104
type specimen figured--.............- Pl. LXXXIV, fig. 4
fissa, compared with Schizambon? esthonia 622
LOCK Ei GISCUSSCO Smee s=e aaa: ses eee ee 622
manitowensis, described ..-.-...-.--.1..-.----- 623
general geographic and stratigraphic distribution tab-
uulatedeso ae penaenn\ssecateseecre ce se acciaaeee aeons 104
type specimen figured Pl. LXXXIV, fig. 3
priscus, described . 623
general meaenrainie and tiaeiitertatle distribution tab-
lated ees ee eects we actee sinc cous seroma 104
type specimen not figured.
pe oHS, CEO AIA os soacooomoneadorenncooscessaccoss26a55 * 624
compared with Schizambon ? esthonia.........-.-.---- 622
Schizambon manitowensis.........-.----------- 623
SCHIZUMUOTADTISCUS = eee ee eeenee eee el eeeeoeeeeee 623
SOMO ROTAD? CUT cosaneosscooseeeosce pasece 626
Trematobolus kempanum 620

general geographic and stratigraphic distribution tab-

Wlated seme cee nessa bene s eses noe cee eens ce eee ee
type of Schizambon...
type specimen figured

Schizocrania, compared with Discinolepis ae
compared with Mickwitzia..........-.-----.--2224-----2--- 331

Sc liezOp LOLS MG eSCriped sews me eeee senor eece sean enes 608

cardinal area discussed..............-. - 305
GERMTGA TON OF so snossotpeodedsoa9e000Isc - 321,324
compared with Acrotreta.......-.-.-..---. Sonate
evolutionkdiscssed esses ses aeeeeeaaeeeeeeaneeeeeeeee 319
evolubiomonseneet Uncaccmecnt onset semaine te seceuenare 317

general geographic and stratigraphic distribution of the
SOHOES MAAR 1O)5 oo scemaoonaeod sobeensacscuse0seos 104

- general stratigraphic distribution and number of
Cambrian species and varieties of.............-..... 110
intermediate between Boisfordia and Acrotreta......-. 602
number of species of, in different types of sediment 160
: type species Schizopholis rugosa 609
Berri gosi described ses.svaccasceecaeaies see eee sack: 609
compared with Botsfordia 602

general geographic and stratigraphic distribution tab:
ulated se sae sk Sea sees eee cee oe sores see ae ees 104
LY DELOMS chizOPNOlis sane net see sane eee ace = se Se 609
type specimen figured -.-.....-.-- Pl. LX XXL, figs. 1, 1a—b

Schizophoria, classification of by Ulrich........................... 308
muscle scars of, discussed by Ulrich............-........-:- 308

Schizotreta, compared with Keyserlingia SOLS)
elliptica, compared with Keyserlingia..............-...----- 628

Schleswig-Holstein, Germany, locality in......................-.. 386e

Schmalensee, G., acknowledgments 12
mentioned. ..-.-.-.- 331
Species named for 411, 709

schmalenseei, see Acrotreta and Obolus.

Schmidt, Hr., acknowledgments...-......---.---.-.--2---0--e0-5 1
bibliographic references. - a 23
MCTIVIONCG ae ch resents = Hes Seatac alone enews einem eee 367
SPEClesmamMeEdhto neater sce) cecis we saeeat em enie sss -eece cele 412
SUI AWIS WENN VI. Soon Aae aaporeqonscodaceseesnecscocacas 442

schmidti, see Obolus. .

Schmidtia, compared with Leptembolon...........-.-.-.-------.-- 378

(Schmidtia), see Obolus (Schmidtia).

Schmidtia conglomerate (Upper Cambrian), in generalized sec-

tion for Russia, listing species and localities.............. 143
localitiestins saAese oes ce see see seca somce eee ce 395s-u

“Schmidtia celata,’”’ type of Obolus (Schmidtia). -. 378, 442

Schodack, New York, localities at...........-..----.------.--- 29a, 338

Schuchert, Charles, acknowledgments...........--.-.--.----.---- 13

bipliograpinemeferences= sees tee eee eee en 2 23
comparison of Lingulella and Lingulella (Lingulepis) by.... 544
penusimam edvorsaasyeneee teas cses sence ena see= nese 585
note on Cambrian spondylia and development of true
Onthids ese eee reece Saeco ae tie be sin belactea eet se seeseeee 308
species named for 3 531
LErminolopysOlesersaeeee seems ce < oe = elec em aie ae mie wees neon 292

62667°—vo1 51, pr 1—12——55

865

Schuchert, Charles [ Winchell, N. H., and], bibliographicreference. 26

schucherti, see Lingulella.

MS CIVIECHETUUIUG ACES CULL G Gl eeatete atest steele taste tee ee erate le
cardinal area discussed!............-...-------------.-
classification of... --
compared with Elkania....
evolution and classification discussed
evolution) discussed amssteseeeseeeee er ae eee ae
UOMO Os ono onunpasococa 2 ocosoubsseessecsasecos
general geographic and stratigraphic distribution of

thespecies referred to.............----------------- 104
general stratigraphic distribution and number of Cam-
brian species and varieties of..........------------- 110
number of species of, in different types of sediment... 160
MOSUL SABO IIRE | = goa tabonsoosen neo naSsoccomecerade 297
stratigraphic position mentioned 318
camoria; described! esse - on cihe sce dsiseicecienice Soar eee ce cece 585
general geographic and stratigraphic distribution tab-
WI ENC l aA Gemmonospocdoan-oonsasoosedoocscscbunozoge 104
surface ornamentation discussed .-...--..---.-------- 303
type specimen figured
Schuchertinidse, classification of....-../.--..------------------- 321, 323
distribution in Cambrian strata. --...........-...-.-.------ 316
genera and species referred to, described......-..-....-..--. 585
general stratigraphic distribution and number of Cambrian
generaiand| SpeciesOine semaceee ener eee eae ee 112
number of Cambrian genera and species of.....--.--..-.--- 112
number of genera and species in monograph....-..-.------- 133
Schuylerville quadrangle, New York, localities in-............-.- 35,
35a, 43, 338h, 338i, 3380, 338z
Scipio Utah localihy mn careers ee sees ese ee eee 331
scotica, see Micromitra.
Scotland, Cambrian species of, listed.............-.-..--------- 120-121
generalized section of Cambrian and Ordovician in, listing
speciesiand Jlocallitieshey ee sa- eee nares eee eerie ee 135-136
localities intr ss Ae Sane ele oon se See eee eee ae 316, 316a-d.
onlyaLingulcllannomeeerereeeereeecerneceene eerste ee caeree 541
sculptilis, see Micromitra.
sculptilis endlichi, see Micromitra.
Seal Point Cove, Trinity Bay, Newfoundland, locality at........: 6w
Secondary vascular canals, shown in figure.............-...-....- 3874
Secret Canyon, Eureka district, Nevada, localities in ........._. 55b, 58
Secret Canyon road, Eureka district, Nevada, locality on......... 204

Secret Canyon shale (Middle Cambrian), detailed section, listing
included and correlated species and localities

localitiestin gs S=sece te eeeca eet cea ae enacts

Sections of brachiopod shells, preparation wi moods cHeSeeSaDBSasoS

Sedgwick, A., bibliographic reference. ...................-..-..--

Seebach, K. von, bibliographic reference.
Speciesinamedittorsapees sea eee oeernc oer eeenee eee

seebachi, see Acrotreta.

Segerberg, C. O. [Moberg, J. C., and], bibliographic reference. .... 21

Sharam, Ne 1s (Os, Salsas oe N TE Os ooo ec eee eseces=cossces2 414
selwyni, see Obolus.
SIIB, CSO TES EL 3 ios Lo amneeadcssdacetcoosvonemasnacesssugesoss 310
Showa imifigures see cencee ascecmeeeee nceee see uecee neon 374
septalis, see Obolus. ie
Septal plates, defined................ 295
sequens, see Lingulella (Lingulepis) acuminata.
sera, see Acrothyra.
Serpulite grit, in generalized section for England, Scotland, and
Wales, listing species and localities...................... 136
Sessile spondylium, defined 295
Shes he uine dee eeee eee eee 362, 374
Setal band, shown in figure aoe eeRycs
Shadow Canyon, Eureka district, Nevada, locality near. - 202
Shale, number of genera and species identified from .............. 160
Shale and limestone, number of generaandspeciescommontoboth. 160
Shale and sandstone, number of genera and speciescommontoboth 160
Shale, limestone, and sandstone, number of genera and species
COTTA CM HAE). - .- — Angcancsooneeasosassodacoseusaous 160
Shaler, N. S., and Foerste, A. F., bibliographic reference. - 24

Shansi, China, Hee NN HES 0) oc ogscscesossoss

iboats, see Obolus.

Shantung, China; localities in=--- 2 -- 2.222222 -e-ssee--22---- n= C1-7,
C9, C10, C12, C17, C20, C22, C23, C26, C28,
C36, C45, C54, C56, C57, C61-64, C67, C68

C37, C71, cr, C74, Cw

shantungensis, see Acrotreta.

Sheep Creek, Wyoming, see Jackson Creek.
Shelby County, Alabama, localitiesin.........
shelbyensis, see Wimanella.

17b, 56c, 141a, 142, 164f

866

Shellistrmeturelee somes. occa 2s0 coe ones cca nec eater eee 296-300

She lJsnbstance, generic importance of, in classification. .......-. 297
NhensyAChinag localities De. - = s-ses see eee eee eee eee eee C32, C32’
Sherbrooke limestcne (Upper Cambrian), detailed section, listing
included species and localities......-.-.-.-.---.----- = IPH)
extension of upper boundary described - ee. 125
Jocalities\im: 222.255 2.04 2.28 eae ance ee eee eee eee 57d, 58f
Sheridan, Wyoming, localities near............-..... 14k, 168, 171, 17la
Sheridan County, Wyoming, localitiesin...... 14k, 168, 171, 171a, 302m
Shimer, H. W. [Grabau, A. W., and], bibliographic reference... . 17
Shineton, England, locality at......................- pee oe eee 304i
Shineton Brook, England, localities on......... Sap ceee cine 3041, 304p
Shineton shales (Upper Cambrian), in generalized section for
England, Scotland, and Wales, listing species and localities. 135
localities see eae ae nearer Beets Oh. 304h, 304i, 304x, 3041, 304p
Shipley, Ferry, Sullivan County, Tennessee, locality mear........ 2
Shipleys, Sullivan County, Tennessee, locality near.............- 374e

Shooks Gap, in Bays Mountains, Tennessee, localities in.. 10a, 10b, 106

Shooks Ridge, in Bays Mountains, Tennessee, locality near. --..- 106a

Shropshire, see South Shropshire.

Shumard, B. F., bibliographic references. ............-.--.-----.. 24

Shumardia zone (Upper Cambrian), in generalized section for
Sweden, Denmark, Finland, and Norway, listing species

and localities iace. mer srsee ete eeerace aecane = eeeiseneee ee 145
locality ine. sce ceeme emetic epee see ei cesar aeeean sen 390b
Shushan, New York, localities near............-..-2..---.---- 36, 338d

Sias River, see Sjass River.
Siberia, Cambrian species of, listed
locality ime see 2c ..sssema cere thee ae eee ees 5
Obolella cf. chromatica from, discussed... -..-.-----.--.---.-
Siemiradzki, J. von, bibliographic reference ............--.--.--.-
speciesmamieditons es ses ceases cena ton seen cece oseercanee
siemiradzkii, see Lingulella.
Sierra Canyon, Eureka district, Nevada, localities in........... 62a, 65
Sierra County, New Mexico, localities in.......-...-. 327, 327a—c
Sierra Springs, Eureka district, Nevada, locality at....... i 56

Signal Mountain, Comanche County, Oklahoma, locality near.... 124
signalis, see Acrotreta.

signata, see Acrothyra and Lingulelia.

signata orta, see Acrothyra.

signata prima, see Acrothyra.

Sillery, Upper (Ordovician), locality in................--...----- 220a
Sillery conglomerate bowlder (Lower Cambrian), locality in --.... 56a
siluricus, see Obolus (Mickwitzella).

Silver Canyon, Inyo County, California, locality in-.............. 7
Silver Peak group (Lower Cambrian), localitiesin.. 11, 1m, Ip, lv, 141?
Silver Peak quadrangle, Nevada, localities in...............-...-. 11,

1m, 1p, 1v, 7r, Ys, Tv, 7x, Ty, 7z, 8a, 8b’, 8r, 174c, 175, 184
similis, see Lingulella.

Simonds, near St. John, New Brunswick, locality in ............. 301x

simpler, see Lingulella and Wimanella.

Simpson formation, locality correlated with..........--- eesorases 105x

Simpson Range, Utah, localities in 32h, 32z

Simpson Spring, Utah, localities near ..... lls, 32h, 32z

Simrishamn, Sweden, localities near......... ... 321u, 321v
localities northwest of. .......---..-------+-------- Sonn th

* 3101, 320c, 320f, 320i, 3200, 320x, 321y, 3900
sinoe, see Obolus.

Sintai district, China, localities in..-.....-......--....-.......... C17,
. C9, C10, C12, C57, C61, C62, C63, C64
Sintaihien, China, locality near C57
SINUS SHOWA ele See eae eee ee ee Sneed asSeaacons 374
Svphonohicto ;deschi bed erese esse e eee e eas eee ase ee ease eee 624
classification of 321,324
compared with Dearbornia..........-.--.------------ 614
Trematobolus 299 x 313, 616
evolution of ‘ 317

general geographic and stratigraphic distribution of
the/species)referred) tos = ===" 2-2-2 2°22 ue le 104

. general stratigraphic distribution and number of Cam-
brian species and varieties of...........---.----..--- 11
number of Ordovician species and varieties of........ 113
number of species of, in different types ofsediment... 160
reference to, of Siphonotreta ? dubia discussed -...-...-..- 626,
surface ornamentation discussed................------ 302

type species “‘ Crania unguiculata”’......-.-.-----.--- 625

#dubiaadescribedirs. nanicese ce enc cecesceu ce cack oe scisccee cae 625
general geographic and stratigraphic distribution tabu-

LE ee ee es ohn do teat c aOR ONS S SO SHR eS AE ASE 104

type specimen figured Pl. LXXXI, fig. 7

CAMBRIAN BRACHIOPODA.

Siphonotreta fissa, discussed ............-..-.-.--------.--- Aas
1a dOgensts;i2) CISCUSSC 0 eee eee eee Eee eee eee eee eee 368, 369

YPC OMMAeElNEnSETC ee eee eee eee eee 367
unguiculata, described.......-. 626
compared with Keyserlingia.. 628
Siphonotreta ? dubia... - 626
Siphonotnete verncosd se -see ne eae eee 627
Gesenibpedremigt GiSGuSSe 0 eee: ee eee eee 625

general geographic and stratigraphic distribution tab-
ulated. : 104

type specimen not figured.

DENTIULCOSM, | GESCrIDEd eee 5 pee ee ee eee eee one 627
compared with Helmersenia ladogensis........-.-..--- 367
Siphonotreta unguiculata.....-......-..--------- 627

general geographic and stratigraphic distribution tab-
Ulated: ee esse ee eee See ae eee eee eee eee 104

type specimen not figured.
Siphonotretacea, classification of ...
distribution in Cambrian strata
genera and species referred to, described................-- 586-630
Siphonotretidee; classification! of - 22-222 - <= soos sane e eee
distribution in Cambrian strata........-.-..-..---
evolution discussed = ses seees=e eee eee eee eee
genera and species referred to, described
general stratigraphic distribution and number of Cambrian

generaland(species of-p-eees-ee a ee eee eee eeeeee eee eeeeee 112
number of Cambrian genera and species of......-.-.- 112
number of genera and species in monograph...-.-....-- 113
number of Ordovician genera and species in monograph.... 113

Sjass (Sias) River, St. Petersburg, Russia, locality on..-..-...... 3361
Skalsternarne Island, near Gefle, Sweden, locality on...-.--...-. 31lo
Skame, (Sweden: localitysineesa- ss seee see eae ee ee eee ene eeaeee 310h

See also Malmohus and Christianstad.
Skara, Sweden, localities near... 309c, 309d, 320, 320a, 320b, 320n, 320y
Skaraborg, Sweden, localities in. 309c, 309d, 310q, 320, 320a, 320b, 320e,
320h, 320m, 320n, 320r, 320y, 321q, 32I1r, 390f, 390j, 390k, 390n, 390p
Sikarosen) Siwedenb locality ates setae eR ee ees eee eee see eeee
Skarpnato, Aland Island, Finland, locality at.
Skiensdalen, Norway, locality in-.........--
Skrej, Bohemia, localities at and near 345, 345d-f, 345j, 345k
Skrena, Norway, locality at ------ 222-20 nee oe eee a... 324a
plap Bohemia) locality: dthe = eeiaees eer eee eee :
Slapnicky mlyn, near Skrej, Bohemia, locality at......-.....-...
Slapy, near Skrej, Bohemia, locality at forester house of
Slemmern, Aland Island, Finland, localities at...-....
Slemmestad, Norway, localities at...:.......-----------------

311f, 31lq, 3lly
8x, 323p

Slough Creek, Yellowstone National Park, Montana, locality near. 302f
Small Hill, Comanche County, Oklahoma, locality at..---...-.-- 12j
Smoithy iH apAN, Speclesma MGC teem ees ea eee i 417
Smith, G. O., bibliographic reference...............-.------.-. S00 24
smithi, see Obolus.

Smith Point, Trinity Bay, Newfoundland, localities on..-.-. 51, bn, 50
Smithsburg, Maryland, locality near........-....--.------------- 47d
Smith Sound, Trinity Bay, Newfoundland, localities on......-.-. 51,

5n, 50, 5s, 6y, 314b, 3141

Snake Range, Nevada, localities in...........----.------------ 8n, 10w
socialis, see Acrotreta.

Séderarm lighthouse, near Norrtelje, Sweden, locality at.-.-...... 31lu
Sédra Méckleby, Oeland Island, Sweden, locality at.......-..--.- 320p

Solva, in generalized section for England, Scotland, and Wales... 136

Solva, South Wales, localities at and near......-...-.-. 3180, 318q, 318r

South America, localities in.............------------------- 389, 389a-d
See also Argentina.

South Argyle, New York, locality near...........-----.- - 3381

South Australia, Cambrian species of, listed......... easy | UPR

IGA MNES MN = ie Seige enscoe see cosodoconsaoecusebsconss 315, 315a-d
South Bessemer, Alabama, locality at.........--..-.------------- 560°
South Dakota, Cambrian species of, listed

localitiestimves:--ese-eeerr 17j, 17k, 88a, 164, 165, 167, 355, 355a-f

note on stratigraphic position of localities in-............-.. 144
South Granville, New York, localities near..........-.-.------- 38, 367a
South Shropshire, England, localities in......-. 304h, 304i, 304-1, 304p
Spain, Cambrian species of, listed........-....--------0--------- 120-121

localitiessines=-eeesee =e eee 350, 350a, 350b
Sparagmite sandstone (Lower Cambrian), in generalized section :
for Sweden, Denmark, Finland, and Norway, listing species
and localities
localiiyalaeee sees ee eee rere 8y
spatula, see Lingulella (Lingulepis).

INDEX.

peciesmbabi ay Of CISCUSSCA se merce ce sceeer eases eee ceeae ene 159
zoological list of, giving page and plate references, and gen-

eral geographic and stratigraphic distribution...-.- 98-109
zoological list of Asiatic Cambrian, giving geographic distri-

ibition byicountniess= snes nee eee ae cece seceenee. 121-122
European Cambrian, giving geographic distribution

loay Colbtal nalts badonsorocodoueusneaoseecesce 120-121

sHIUITO PCA OL OwAClaNes eer eee ence aene st eeeeeeeeeee 123
North American Cambrian, giving geographic distri-

bution by States and geologic provinces ......... 114-119

North American Ordovician.................... 122-123

South American and Australian:‘Cambrian.:........- 122

Spence; R.S:, species named for.-.-.---..---.--- 2... 222-2. 2 ee 737

spencei, see Nisusia (Jameselia).

Spence shale (Middle Cambrian), apparent equivalent of, in de-
tailed section in House Range, Utah, listing included and
correlated species and localities.......-..............----- 158

in detailed section in Blacksmith Fork, Utah, listing in-
cluded and correlated species and localities.............-- 152

Spence shale member of the Ute formation (Middle Cambrian),
LOCaiG Sin see cele aes seine ieee 31d, 32p, 541, 55c, 55e, 163

Spines, presence in Brachiopoda discussed.............-...---.--- 302

spinosa, see Acrotreta.

RS /Denty Cini CM LION Mss eee ie tieciti cise cena nsicscneseeeeeneas 785

spissus, see Obolus (Lingulobolus).

Nplancvhnocosien denned eer essa sete eer eee reac eee eee eee eee 295

SILO WUE TUE PUTO Se eteserefeterelare eliicie retere tices ec oicl= eee see 374

Sjomaehy Mina, Coils Soo o5- ce soeas eed s Asse ae Aon ene ban meceeena 295

@iscuSsedteer te eee ee eee
Schuchert on.
Ulrich’s notes on
Sponge Mountain, Llano County, Texas, locality near..:........-
Spring Creek, near Center, Alabama, locality on......-..-...--.-
Springer, Oklahoma, detailed section of Arbuckle limestone near,
listing included and correlated species and localities ... 141-142
HOCH ES MeaT ante ntniatteeimnle secs alee see se iaiat 12k, 12m, 12n

Spring Hill Canyon, Bridger Range, Montana, locality in........ 147a
Spring Mountain Range, Nevada, locality in-.......-...-.-...... Tn
spurri, see Acrothele. abs

squamosa, see Lingulella (Lingulepis).

Sta. Benigna, Bohemia, locality at.........-.-----.---..---.----- 303e
Stansbury Range, Utah, localities in.... 32f, 32g, 32j, 32k, 320, 34u, 34v
Staroja Ladoga, Novgorod, Russia, locality at...........-........ 336j
(SiimmaP, TR TPL, SiasOes EMME e Sess e coed ebodebosebenecasdenaser 559
starri, see Lingulella (Lingulepis). .»

Steel Ford, Cowan Creek, Alabama, locality near..........-...-.. 94
Stenotheca, reference to, of ‘‘Discina czrfaiensis” discussed......-- 723
Stephen, British Columbia, localities near................--.----- 35c,

35g, 35h, 57¢, 57g, 57k, 57s, 57y, 58z
See also Mount Stephen.
Stephen formation (Middle Cambrian), detailed section listing
included and correlated species and fossils...-....-.---- 127-128
lo caIGIeS HM seria ce = eae aicatere a nese sate sista eine eioaieiels eelareeaie i4s,
35k, 57c, 57f, 57g, 57j, 57k, 57y, 58i, 58j, 581, 58r, 58w, 58z
Stillwater, Minnesota, localities at and near... . =...-- 339, 339b

Stissing, New York, locality near 367d.
stissingensis, see Micromitra (Paterina).

Stissingensis ora, see Micromitra (Paterina).

Stissing Mountain, New York, locality on................-..----- 32
Stockholm (Province), Sweden, localities in 31la,

311p, 311u, 31l1v, 321, 321a-d, 3210

Stockingford shales (Upper Cambrian), locality in....-.......... 304j
Stockport paper mill, Columbia County, New York, localities

THER cco o saan nocgesRE AU seOCeD OOO AOOU REDD eC OEEROOESSe 29, 338b
Stone, R. E., species named for 466
stoneanus, see Obolus ( Westonia). Pe
Stoner, Pennsylvania, locality near.........-...--...--.--.------ 50

310e, 310g, 390a
392a, 392c, 3921

Stora Rér, Oeland Island, Sweden, localities near... ...
Straits of Belleisle, Labrador, localities at...........-.

Stratigraphic and geographic distribution tabulated............. 98-109
Stratigraphic sections with correlated faunal lists. . . - 123-159
Streitberg, Esthonia, Russia, locality at.............-..--...----- 396r
striata, see Billingselia.

Stricklandinia, compared with Syntrophia..........--.----------- 798

? arachne, generic reference discussed. -.. - - 798

? arethusa, generic reference discussed... .-. 798
Strophomena, compared with Hostrophomena 796
3 reference to, of Hoorthis atava, discussed. -.-...-.-.----- 774
Eoorthis johannensis, discussed ce GER

Protorthis hunnebergensis, discussed... ......--- 741

Strophomena—Continued,

aurora, compared with Hostrophomena elegantula.......---- 796
rhomboidalis, compared with Hoorthis johannensis....-..---- 781

“Strophomena or Strophodonta,”’ compared with Hoorthis johan-

MENSIS.. OL. Tees Scar a Ra eee er epee etc Sec seas 781

“Strophomena( Eostrophomena)elegantula,”’ type of Eostrophomena. 796

Strophomenacea, classification of............-----.------------- 321, 326
distribution in Cambrian strata........------.------------- 316
genera and species referred to, described.....-.----.----- 795-796

Strophomenidz, cardinal process, discussed......--.------------- 306
classification‘of: 5s. sees Sect aaa eee cee eco ace 321, 326
cruraliim mentioned tases seeree eee nee eeneee eee eee reese 309
distribution in Cambrian strata.-......--.---.-.----------- 316
genera and species referred to, described.--...-...-.----- 795-796
general stratigraphic distribution and number of Cambrian

generayandispecies | oleeeeeee see eeee eee eee eee eee ee eeeee 112

no interiors seen!) 69/5 seis Se eek Ss Se oe ee eee eee 312
number of Cambrian genera and species of...-....-----.--- 112
number of genera and species in monograph.......--------- 113

Siructure ofthe)shells-cn- ete eee ee eee eee 296-300

stuarti, see Micromitra (Paterina).

subconica, see Acrotreta.

subguadrata, see Nisusia (Jamesella) perpasta.

subsidua, see Acrothele.

subsidua hera, see Acrothele.

subsidua levis, see Acrothele.

Sularp, near Lund, Sweden, localities at-............-.....-- 321s, 321t

sulcata, see Acrotreta idahoensis and Eoorthis remnicha.

sulcatus, see Discinopsis.

Sullivan County, Tennessee, localities in............. 2z, 2z', 374c, 374e

Summary, tablesseciaseceemccese cease ee cee eee 110-113

Sun River (North Fork), Powell County, Montana, localities near. 3j, 5j

superba, see Micromitra (Paterina).

Surface ornamentation, discussed.............-.----------------
importance of, in classification.........

Sussex County, New Jersey, locality in

Swallow ranch, White Pine County, Nevada, locality near....... 8n

Swansea (Viola), Alabama, locality near.......................-- 144c

Swanston, W., bibliographic references............--------------- 24

Swanton, Vermont, localities near.......-.....- 25a, 28, 319e, 319r, 319z

swantonensis, see Micromitra (Paterina) labradorica.

Swanton ;described= ses: seess settee sea eee eee eter een eeee 796
cardinal area discussed..........-. 305
classification of.-....-...-......-.- . 321,326
compared with Camarella 797
evolution discussed 320
evolubion/ofieseesremcinsce cece ceeeneh ne eacelemee ser = 317
general geographic and stratigraphic distribution of

tThe|speciesreferred (Ones renee eee ees ane ee eee 109
general stratigraphic distribution and number of Cam-
brian species and varieties of...-.............-...-- 111
number of species of, in different types of sediment... 160
stratigraphic position mentioned..................--- 318
surface ornamentation discussed./................---- 303
type species “‘ Camerella antiqua’’.................-..- 797
antiquata, described.........-...-....-.--- 797
compared with Huenella vermontana 809
general geographic and stratigraphic distribution tab-
WENT Eeansapapanoauadoodsonsauenoreatasaatasvosccn 109
type specimen not figured.
weekst: described): ae. p same eee era fee ae nee een 797
compared with Swantonia antiquata 797
general geographic and stratigraphic distribution tab-
Uae ae Sat ale ys aniaiar Gera eee SN GU) ta (ale 109
type specimen figured..............- - Pl. CIV, fig: 6
Swarow, Bohemia, locality at. 2.2.2.2 2.222222. - 2 eee een c ene 303d.
Swasey formation (Middle Cambrian), in detailed section in House
Range, Utah, listing included and correlated species and
NOCalibleS pater aeere tee eisictejopeeete eteacharaie terete eae a alaieloinve es arsierete 157
localities in : -- llw, 30d

Swasey Spring, House Range, Utah, localities near.... - 15b, 15¢e

Swasey Spring road, House Range, Utah, locality on ............ llo

Sweden, Cambrian species of, listed......-...........------ .-- 120-121

generalized section of Cambrian and Ordovician in, listing
included and correlated species and localities........... 144-146

localinestinizeen eee se eeaes 8w, 8y, 8z, 9e, 309, 309a-f, 309h-j,
309 1, 309m, 310, 310a-z, 311, 31la-c, 31lg—p, 311lu, 311v,
320, 320a-z, 321, 32la-v, 321x-z, 323j, 323k, 390, 390a—p
species of Obolus from, listed 379
stratigraphic position of bowlders in Baltic region discussed. 454
See also separate provinces.

868

Synonymy, alphabetic index to.--.-..---------------------------- 27-98
Syntrophia, described... -..-------------------------+------------ 798
compared with Clarkella....------------------------- 809
Dicellomus..-------- 572
Huenella.-..-------- 805
eruralium discussed 307,309
evolution discussed 320
eVOlIULON Osea eee eee eee eee ee eee 317

general geographic and stratigraphic distribution of
the species referred to._..-.------------------------ 109

general stratigraphic distribution and number of Cam-
brian species and varieties of. .-.--..--------------- lll
number of Ordovician species and varieties of........ 113
number of species of, {n different types of sediment... 160

reference to, of Huenclla abnormis discussed. -----.--- 806

type species ‘‘ Triplesia lateralis”’.....-+.------------- 798
shell structure compared with that of Huenella - -- 300
spondylium discussed 307
typical Cambrian species Syntrophia rotundata....---- 798
Ulrich on spondylium).-..------.---.-.2----2-------- 308
(RIT, GEORG 355-23 coo aaecoosseasecen SaaS yoeses2e92 799
general geographic and stratigraphic distribution tab-
DI lo See hes ocane soca ssasesoacoooaescectsaeecs 109
type specimen figured .--- Pl. CIIl, fig. 3a
barabuensis, described-*...-.--.----2------.---------------- 799
compared with Protorthis helena 740
Syntrophia primordialis.. 804
SYMITO PAO UME. «=a = mee =e = = = 805
general geographic and stratigraphic distribution tab-
lated epee Semen eee amacrine aero erence = 109
type specimen not figured.
COICIfET Un OeSCHIDE Caen eee a= ee ee 800
compared with Clarkella montanensis......--.-------- 810
SHAHID To = sonccassoccsoce nese s5eecezens23 798
Syntrophia cambria. 801
Syntrophia nundina..---- 802
Syntrophia primordialis 804
general geographic and stratigraphic distribution tab-
THEW oe oc Recoacedorssdaosaa soa ere aeaneeeee 109
surface ornamentation discussed. - 303
type specimen figured. Pl. CIV, fig. 1e
cambria, described 800
general geographic and stratigraphic distribution tab-
UWlahed rem seee ase! cae nee ose se sere ee anen ea 109
type specimen figured text fig. 72B, 800
COMPDEH Ps CeSCTID COe esas em saee eerie ee ae eee a 801
general geographic and stratigraphic distribution tab-
(HILT os oa oc coseneenanoeenerosarenssescoresEbona9 109
type specimen figured....... coseoss . text fig. 73A, 801
LOten ots. eSCr OG Uer setae eee eee ee 802
compared with Syntrophia rotundata.....-.---------- 804
described in text following generic reference.........- 798
general geographic and stratigraphic distribution tab-
UIE «= paaossonosadese coosesoupoSTcocesoansucases 109
shell section figured .............--..------- text fig. 11, 299
shell structure compared with that of Huenella ab-
LOTS ee See ee es 300
type specimen not figured.
CPM Pak, (BESET EE Loo ose os ce sone sector sageceons socksessce 802
_compared with Syntrophia calcifera...-.....---.------ 800
Syntrophia cambria 801
general geographic and stratigraphic distribution
POMEL. senso cseacdossanoosecsnenstesose sans 109
type specimen figured Pl. CIL, fig. 4
Cid eplesOnleee |= Me 5 -eteinnsoanoesuenodasap sesoneaeHesennS 803
general geographic and stratigraphic distribution
ablated meee seme sees aee = eee eee aera 109

type specimen figured. .

TOMAOON DS, COREE 6 oe oe Sarco pe cone soe Sone e Re etoseooe 803
compared with Huenella billingsi......-.-.----------- 806
Syntrophia barabuensis......--.--.------------- 799
SUMETO PGC ICH En Cee tae eee ee 800
Syntrophia orthia 803
Syntrophia primordialis argia...-..------------- 804
SOPDMOO UD ONT» ome 225500 252 eee sec stosaeeos oe 805

general geographic and stratigraphic distribution
tabulated 109

CAMBRIAN BRACHIOPODA.

Syntrophia primordialis argia, described ........--.--.-------_-.-- 804
general geographic and stratigraphic distribution
tabulated! as2e-ne-ecese ss na-ner neta Eee ener 109
type specimen figured....--.---.-.__.._____. Pl. CI, fig. 3
Mon pilti, OOS MN. — ons scacsoconosconsdite 2o22sasesenseecre 804
compared with Clarkella montanensis........-...-..- 810
Syntrophia campbelli 802
cruralium discussed 309
general geographic and stratigraphic distribution
tabulated 2: 2sscteccaecsines i tseeccs sees eee eee 109
has a descendant in Clarkella montanensis..........-. 810
spondylium or eruralium discussed. ..-.....--.-.--.. 307
typelspecimen fig ined 22s. see eee eee Pl. CII, fig. 4c
typical Cambrian species of Syntrophia............... 798
“terana,”’ type of Huenella 805
Pumcia, GescribeGsessse sees sesee ee 804
general geographic and stratigraphic distribution
tabulated): 52325 lStsc- st eceee yate eee eee ees 109
type specumenthie ured = ees ee essen text fig. 74,805
Syntrophiide, classification of.......-.-..-.----.-.------------ 321, 326
distribution in Cambrian strata.......-....-....-.----.-.-- 316
genera and species referred to, degen Hosea eee ee 796-810
general stratigraphic distribution and number of Cambrian
genera and!species Ofe s-- es ese ee esnse ete ees 112
number of Cambrian genera and species of 5 aliby
number of genera and species in monograph 113
number of Ordovician genera and species in monograph. - 113
SEINE GUISCURSEGl - 5 o-oo o aps aoseoasoassoseneseseseasce tothe 310
(UlrichYon'spondylivimr epee ees] se eee eee eee eee 308
Systemic reference of formations discussed ................--..--- 98

taconica, see Acrotreta sagittalis.
Tafern Helig, North Wales, locality at
Tai-hirion, Wales, locality near
UrrAbnets, (Claret Moyer hi eMicet geo so sesse secon con sc onseooe
Taquamenon Bay, Michigan, locality on
tarpa, see Lingulella.
Tate, R., bibliopraphicireference e-em. ner sae sa = eee ee
species named for
tatei, see Eoorthis.
Tatur Hill, Burnet County, Texas, localities on ......-.--- 67, 67c, 67z
Taylors Falls, Minnesota, localities near 82b, 339d, 3397

Tazewell road, near Knoxville, Tennessee, locality on-........-.. 118
nego (olsobaeels es esse oecoees sosceeese nos esoasseeseeseeecssod 295
Tejiovik, Bohemia, localities near 345a, 3451
Mel one rte ely Cen 00 e Camere lee 295
Temiscouata County, Quebec, localities in --. 2n, 3191
Tennessee, Cambrian species of, listed 114-119
generalized section of Cambrian in, listing included and
correlated species and localities...............-----.-....- 147
NaeHMNES Mal - —--s scopssonssa7esesass so yeecIsessteo3cssaose2¢ 2z,

7d, 9, 9a, 10a, 10b, 11, 11a, 12, 12q, 13, 13b, 14a, 18, 10],
101a, 101b, 102, 102c, 103, 103a, 103b, 104, 105, 106, 106a,
107, 107a, 107b, 1070, 107n, 117, 117c, 118, 119, 121, 121a,

122, 122a, 123, 124, 124a, 128, 128a, 374, 374a-6
tennesseensis, see Linnarssonella.
Tepee Creek, Bighorn Mountains, Wyoming, locality on..-...... 168
Terminology adopted 291
Terminology of different authors tabulated. ...............-.-.... 292
Terrapin Creek road, near Center, Alabama, locality on.......... 93a,
tetonensis, see Acrotreta microscopica and Obolus.
jetonensis Ieda, see Obolus.
zelonensis ninus, see Obolus.
Teton Mountains, Wyoming, localities in-............... 4e, 4m, 4n, 40
texana, see Eoorthis remnicha, Huencella, and Lingulella®
terana lxviusculus, see Huenelia.
Texas, Cambrian species of, listed!.---.....-.---.--..----.--..-- 114-119

localitieshineseosssseee esses 14b, 14c, 14e, 14g, 14i, 14q, 14r,
67, 67¢, 67z, 68, 68e, 68y, 68z, 69, 70, 70a, 70e, 71, 353, 353a-c

note on stratigraphic position of localities in.........-...... 148
THeca, ASSOCIALION MEMPONEW 3 mee eee eee ee 767
themis, see Obolus ( Westonia).
Theresa, New York, locality near-..--....----.-.-.-------------- 185a
Thermopolis, Wyoming, locality near....-.-......--..---.------- 302p
Thomas Mills, Floyd County, Georgia, locality near.............. 140a

Thomas ranch, Juab County, Utah, localities near

Thomas Range, see Dugway Range.

Threelorks quadrangle, Montana, localities in 4g,
4h, 4k, 4p, 149a, 150a, 152a, 152b, 153, 153a, 154, 155,
155a, 156b, 157, 158, 158a, 160, 160a, 302k, 302t, 340b

INDEX.

thyone, see Loorthis.

“«Thysanotos,” compared with “Acritis,’ ‘ Euobolus,’ and
EY SCH MiZnG iD yg NLC KWiAtZ ears Gana eee eee ee eee 434
TM GMMLOME Memes me eyes cicisie =e Soeiste ees eloe cleats cieeenies stein 437
Miconderoga, New York, locality mear.......-...--.-------------- 367¢
Tihala, Esthonia, Russia, localities at...............--- 395a, 395h, 395n
Milcuya;sArgentina, localityial 25-2552 s- 0. - eee eon = 389b
Timpahute Range, Nevada, locality in-- . 3g
Tinghianghien, China, locality near ----. eas (ORY
Tintic special quadrangle, Utah, localities in........-.......-..- 34n, 34s
Tischer, Msthonia, Russia, locality at..........--.-.-------------- 396h
Toien, near Christiania, Norway, localities at .......--- 323 I, 323y, 3232
Toll, H. von, bibliographic reference_.........-.-------.---------- 24
Toll Gate Canyon, White Mountain Range, California, localityin.. 8b
Tombstone Gulch, near Bisbee, Arizona, locality in.......-.--.-.- 14x
Tomten, Norway, locality at.............-.-....- 324

Tonto group (Middle Cambrian), localities in.

Tonto group (Upper Cambrian), locality in..... 75
“Tonto”? sandstone (Middle Cambrian), localities in---.-.- 17c, 73a, 74c

POM HONS Cae ee eee = SHUR. ee ceria es stan 429, 516, 524, 558
““Tonto”’ shale (Middle Cambrian), locality in.......-.-...------- 74d
Mooele| County. Uitah, localitiesiimes- se. -2e see ese eee eee 3c-e,

lls, 15p, 15x, 32f-h, 32j, 32k, 32t, 32z, 33f, 34u, 34v, 329e
Topsail Head, Conception Bay, Newfoundland, localities at..-..- 1,
2a, 41a, 314e

Torellella lxvigata, stratigraphic position of bowlder containing,

GUSCUISSE Ceres se eta ate aerate ae ean ave rere ch fe 454, 684
torrentis, see Lingulella and Obolus.
Torryburn, near St. John, New Brunswick, localities near-.-....- Qs, at
Tosterup, Sweden, localities at-...........-2-...---.--- 310v, 323j, 323k,
Towner’s ranch, Lincoln County, Nevada, locality near..-....-.- 14m
Town Knobs, Hawkins County, Tennessee, localities in-.-...-..- 103,
103a, 103b, 122
Mradjersweden localitveat..<2.22= saa. 0 s- sees soe coeecse secs soae 321n
Transmedian (rotator) muscles, defined. ......-..-.-.-.-.-------- 295
SHOWIN SUC seen e ne tee eee och ano ye ect ecieiseee eels 374

ransversa, see Acrotreta sagittalis, Linnarssonella, and Nisusia fes-
tinata.
eiransverseiaxis; defined a2 se oes saa se eco cose ce Seaiee Sateen ese
Ebrapezoidaliarea,: Genmed)-=3- 8222-22 = ees o= eee see ee see = 296
Tremadoc, Wales, localities at and near......-.--- 305c, 305d, 318t, 3661
Tremadoe (Upper Cambrian), in generalized section for England,
Scotland, and Wales, listing species and localities......--- 135
Tremadoc, Lower (Upper Cambrian), localities in..-.. 305, 305c, 305f-j
Tremadoc, Upper (Upper Cambrian), localities in. 305a, 305e, 366p, 366q

Tremadoe shale (Upper Cambrian), locality in. .. 318w
Trematis, compared with Discinolepis.....-.--.--------- .. 664

“pannulus,’’ type species of Micromitra (Iphidella) ......--.- 359
eTremotouolus WAeSCLIWE ear acm ace ce emia ee cea eines ese 615

articulating processes discussed ...........--.--------- 307

candina liareatGiscussed assess see en ease eee sean 305
classifi catiomrol 22s - ese ceme fee ccm ieee csseee 321,324
comparedawitheAlcroflelese=s ese = eee ee ae ee eeee 631
DD COT DORN IG Seve Ra Ne ras ere 2 313, 614
Ono ea Se ot eee Bae ANE REEL cea wees Masse Jere 587, 588
Obolus -..- - 313
Schizambon -- 313
Siphonotreta....-..-.--- 3 BiB}
Yorkia? washingtonensis........---.-.--------- 613
@QHOlwiioia ChiCU SINC ae ek see csces sce sscuoaseadzec 319
evolution of 317
general geographic and stratigraphic distribution of
bhejspecies|reierred sto sae se eee eee eee eee 104

general stratigraphic distribution and number of Cam-
brian species and varieties of. .....-.-...-.---.----- 111

number of species of, in different types ofsediment.. 160
reference to, of Trematobolus excelsis discussed... ------ 615
Shellismbstances=s. sesso eee see nee ae = 297
surface ornamentation discussed -- 302
type species Trematobolus insignis 616
Vvasculan markings discussed--.----- 222-25 -2-2ee5--= = 311
CZCELSTS HOCSCLIDE ana oes aa e See ees ERE aos Aen ae 617
cardinaltarea discussed es. s— =a ee = eee eee Se eeeee 305
compared with Dearbornia clarki..........-.-.-------- 615
Trematobolus kempanum...-------------------- 615
general geographic and stratigraphic distribution tab-
lated ees ge2 5. es Scant oe se eeseieee nas see eemac eee 104
oldest known brachiopod - 316, 616

type specimen figured ............-.-.- Pl. LX XXII, fig. 8

Trematobolus insignis, described ....---.------------------------- 617
described and’ discussed..-.....-------------------.--- 616
compared with Trematobolus excelsis....-------------- 617

Trematobolus kempanum 616, 620
Trematobolus pristinus ... - 616, 621
ST aoe lameness aaa ae sin oh onekootsesece sees 611

general geographic and stratigraphic distribution tab-
Wate deessseeceee= see Poe ee PER eee eee rere eee 104
yD OL MAMET LO DOLLS ene nee ee eee 616
type specimen figured .....-.-.----.--- Pl. LXXXIYV, fig. 5
Kenupaniwm describe dee s== ses ee eta s eae eee ae 619
compared with Yrematobolus excelsis ...--.---------- 615, 617
Trematobolus insignis .....--.------------- 616, 618, 619
Trematobolus pristinus ....------- 621, 622

general geographic and stratigraphic distribution tab-
Tilaite dizeze Seen Set eee ne eee tee ney ieee 104

type specimen not figured. :

pristinus, described... ..-- Scar BLN) iis en oa ete ee awe er 621
compared with Yrematobolus insignis... .-.----- 616, 618, 619

general geographic and stratigraphic distribution
tabulated Rama seten cst eer eeer te mamas eee 104
type specimen figured .-....-....- 52 A WAS OcCun, sik

Trempealeau, Wisconsin, localities at and near........-...------- 83,

83’, 833, 834, 135, 135b, 135¢, 328
Trempealeau County, Wisconsin, localities in.....-......--..---- 79x,
83, 83’, 83%, 834, 100a, 135, 135b, 135¢, 328g

triangularis, see Obolus.

Trimerelia, classification 310
compared with “Zakhmina linguloides”’- - soe AG)
SINICODOLULSIUUOI aes ee eee eee eee 566

development mentioned ses sees ssenee see 561

Hall and Clarke on development of...........----.--- 309

mentioned 4iW Sau reece sous enim See ens sees eee 297
Dlatfonmimentioned sess ees see eee eee anne eee 309
“Tindstromi,” compared with Neobolus warthi......-....-.- 565
Trimerellidz, development of...........-.---...- 310
Trinity Bay, Newfoundland, localities on 51,

5n, 50, 6g, 6h, 6w, by, 314, 314b, 3141
triparilis, see Lingulelia.

COUT DLES ORLULEN CLUS a Cl CSCI CCl Cee ee 798

NATO CH SOMO Ht ome ooo Ssencrccnassacoseecseecsensacoecass 798
“ Triplesia primordialis,” mentioned ......-...-..----.----------- 798
Trois Pistoles, Quebec, age and relations of conglomerate at.... 350,351

localiiaeshatjememsesesee a: pee esac serine eeee eee See ee 2n, 3191
Trout Brook, Cape Breton, locality near_.../.....--...-.--.-..-- 3252,
Trout Creek, near Manitou, Colorado, localities on......-... 360a, 360
Troy, New York, fatma at, discussed--.--.-.-.------.--------- 472-473

localities at and near.... 2b, 2d, 27, 27a, 44a, 338q, 367, 367b, 367i

Troy quadrangle, New York, localities in.........-.....-.-....-- 2b,
2d, 27, 27a, 44a, 338q, 367, 367i
Trubin, Bohemia, locality at.........--...--. wees Senor sees e eee 3038a
Truthville, New Work, locality near-....----....._....-._.._..... 38a
Trwyn-y-lago, North Wales, locality at.........-...-..--..-..--- 305i
Tschurskaja Station, Siberia, locality near_.-................-... 347
Tsinan, China, localities near.-...-.........----.-.-..--- C54, C56, C67
Eilers y Speake SPECleSs MATIC COL sees e eee e eee en ae ae 790
tullbergi, see Eoorthis.
tumida, see Lingulella.
Tungyu, China, locality near...-.-- 2 (expt
Turkeytown, Alabama, locality near - 145

Turner, H: W., bibliographic reference... ..- Ee 24

SpeciesinamiedkOn=e eer hen eee reer eee eae 660
turnert, see Acrothele.
Mursel; Hsthonia, Russia, locality ate----2--------------------.--= 337£
Twobit, Black Iills, South Dakota, locality near...............-. 17k
Twomile Canyon, near Malade, Idaho, localities in............... 4y,
5a-c, 5h, 54s, 54t-x, 55d
Tyler Springs, House Range, Utah, locality near..........-...... 8k
typicalis, see Schizambon. Y
Uinta County, Wyoming, localities in............- 4e, 4m-o, 302d, 302v
Uinta Mountain uplift, sediments derived from. 148
Ulrich, E. O., acknowledgments 13
on spondylia of Cambrian and Ordovician Protremata-..... 308
Speciesmamed Monee gone ces ce = seem ee eee eeoeee aeons 714

ulrichi, see Acrotreta. 8

Ummbod efined Egan ese sese a sesce eee teense eee eines. es 296
Wimibonalicavitiysidetine desese == esse eee eee eee ae eee 296
(Umibonallimusclemde fined ees-s-ee-seceen see eee eee enee eee 296
Wim bonalemuscl elds cussed see sae ee eee 313

870

Umbonal muscle scar, shown in figure
Umbonal slopes, defined.....--.---------------------------------
undosa, see Micromitra (Paterina).

unguiculata, see Siphonotreta.

“¢ Unguia ovata,’’ mentioned .......-.--------------------------- 383, 444
Ungulite grit (Upper Cambrian), in generalized section for Russia,

listing species and localities. --.-.-..-.-.----------------- 143
IG GRINS Tih ee ecadsccteosecossesosesene 336h, 3360, 336p, 336q
Union County, Tennessee, locality in-.......--------------------- - lla
United States Geological Survey, acknowledgments.-...--..-..-- 13
unzia, see Syntrophia.
upis, see Lingulella.
uplandica, see Acrotreta. »
uplandica liméensis, see Acrotreta.
Upper Cambrian, Alabama, generalized section, listing included
and correlated species and localities. ---.-.--.------------ 147
Alberta, fossil horizons correlated with those of British
Columbia seen ae ee ee ee ee ee 125-126
British Columbia, detailed section, listing species and lo-
(GHD Sion ee Ge soa econo ess tsanS cede sonotspoesSasesoto sce 125-126
British Columbia, upper boundary extended ...-.-..--..--- 125
Cape Breton, generalized section, listing speciesand localities. 131
Denmark, generalized section, listing included and correlated
species and localities.........--.------------------------- 145

England, generalized section, listing species and localities. 135-136

TEMAS WGI. 2 oot scab sanecioee Hopes sborssedoteescesere 112
Finland, generalized section, listing included and correlated
species and localities... .......-.-------------------------- 145
genera listed....-...---------- 110-111, 317
Georgia, generalized section, listing included and correlated
Species and localities: = 2-2 so- 22222 nee ee 147
Missouri, generalized section, listing species and localities... 137
Nevada, detailed section, listing species and localities. ----- 139
New Brunswick, species and localities in, correlated with
thoselof Cape! Breton == 2-2 = - === ee ee 131
Newfoundland, detailed section, listing species and locali-
HES Shere et ce See eee eee eee eee ee ec eeiarae 140
Norway, generalized section, listing included and correlated
species and localities. .....-..---------------------+------ 145
Oklahoma, detailed section, listing species and localities.... 142

Russia, generalized section, listing species and localities... 143-144
Scotland, generalized section, listing species and localities. 135-136
SDeClesiSte Geren eee rama amen er eee eee 98-109
Sweden, generalized section, listing included and correlated

Species|angd locales Eee ena= == eee ee 145
Tennessee, generalized section, listing included and ‘corre-
lated species and localities....-.-..----------------------- 147

Utah, detailed section, listing included and correlated spe-
cies and localities. --------------------------_--- 148-149, 153-154
Wales, generalized section, listing species and localities. ... 135-136
Upper Ffestiniog group, in generalized section for England, Seot-
land, and Wales, listing species and localities _........-.--
Upper Leitches Creek, Cape Breton, localities near--.-.--....-.-.-- 8d
10e-h, 10m, 372, 372a

Upper Lingua flags, in generalized section for England, Scotland,

and Wales, listing species and localities. ..-...----------- 135
Upper “Linsenschicht,” in generalized section for Russia-------- 143
urania, see Linnarssonella.
Utah, Blacksmith Fork section, in detail, listing included and cor-
related species and localities.......-.-.----------------- 148-153
Cambrian species of, listed 114119
detailed sections of Cambrian and Ordovician in, listing
included and correlated species and localities.....-..--- 148-158
House Range section, in detail, listing included and corre-
lated species and localities........-...------------------ 153-158
localities in 3c-e,

3s, 3t, 3w-y, 4, 7w, 8g, 8i, 8k, 10y, 10z, 11n-q, 11s, 1lu,

llw-y, 14t, 14v, 15b-d, 15p, 15x, 30a, 30c, 30d, 30e, 30g, 30h,

30j-q, 30s, 30u, 30w, 30y, 30z, 31c-e, 31h, 31 1-n, 31q, 31s,

31t, 31lv, 3ly, 31z, 32c-k, 32n-p, 32t, 32x-z, 33d, 33f, 33i,

33j, 33 1, 33n, 33r, 33t, 34g, 341, 34m, 34n, 34q-v, 54a—r, 54y,

55e, 55h, 55n, 55t, 55u, 105t, 105x, 185z, 329, 329a-e

Utah County, Utah; locality i= =22-----——---—------- === Tw
utahensis, see Micromitra (Paterina) labradorica, Nisusia (James-

ella), and Otusia.

Ute limestone (Middle Cambrian), in detailed section in Black-
smith Fork, Utah, listing included and correlated species

UALR OC SCS eae ee 150-152

localities in 31c-e,

31z, 32e, 32p, 54a, 541-p, 54y, 55c, 55e, 55t, 59f, 59g, 163

CAMBRIAN BRACHIOPODA.

Ute Peak, Cache County, Utah, locality near................--.- 329a
See also Paradise Dry Canyon and Blacksmith Fork.
Veekker6, Norway, locality at ........-...-..-.-..-.-.---------.- 3238e
“Vaginatenkalk” (Ordovician), in generalized section for Russia,
listing species and localities. ......-.-....-..------------- 143
NOVEM ES MB oo 232 22555225 assKe= 3362, 337, 337%a-c, 337f, 337¢
-“Vaginatum limestone”’ (Passage beds), localities in........ 396n, 396p
Vaginoceras limestone, equivalent to the Orthoceratite limestone.. 628
in generalized section for Russia, listing species and localities. 143
Valatie Kill, Rensselaer County, New York, locality on.....-..-- 44a,

Valbom, see Monte de Valbom.

Valcalda Spring, Esmeralda County, Nevada, locality near. -.---- lv
Valley Creek bridge, Bessemer, Alabama, locality near
Van Ness quarry, Lodi, Wisconsin, locality at
Vanuxem, L., bibliographic reference......-....----------------- 24
varians, see Orbiculoidea.

Vascular canals, shown in figure.....-.-:.--.-------.-----.------- ‘374
Vascular markings, discussed... -- 311-312
Vascular (pallial) sinuses, defined 296

variation in position of, in Obolus and Lingulella, and their
EWN ahce ate ss 4 docs sogas sSeaDossUSctesbeesaeesss 376-377

Vassar College, near Poughkeepsie, New York, locality near 3676
Viistergotland, see Skaraborg, Wermland, etc.

vaticina, see Nisusia.

Ventlinge, see Wentlinge.

Ventralivalivye; defined 222) 5es scene as eeee eee eee eee 296

explanation of absence in collections of T’rematobolus 617
vermilionensis, sec Obolella. ~
Vermilion Pass, Alberta, locality in. -.-- “Le See Se ee 60b
Vermont, Cambrian species of, listed. ..........--.--------.---- 114-119
localitiesiiniesene === es eaeae eer ees 16n, 25, 25a, 26, 28, 28a, 87,

227, 319e-g, 319j, 319k, 319m, 319q-s, 319v-z, 3920, 392p
note on stratigraphic position of localities in.....--...--.--- 159
vermontana, see Huenella.
de Verneuil, E. P., bibliographic reference..........-..---.------- 24
de Verneuil, E. P., and Barrande, J., bibliographic reference
Vernon, Utah, localities on stage road west of... - 11s, 32h, 32t, 32z, 33f
verrucosa, see Siphonotreta. ;
Vestergotland, see Skaraborg, Wermland, etc.
Vestfossen, Norway, localities at.........-..----------- 323f, 323h, 323n

-

Villa Boim, Portugal, locality near..........-.-..-------.-------- 351

villaboimensis, see Acrothele.

Vinala, Sweden, locality at..-.-.---------.----.---------- 7. -- = 320V

Viola, see Swansea (Viola).

Virginia, Cambrian species Of listed Sass a eee eee eee eae 114-119
localities‘in=:. 2-2. 2 S2tes see 2eee See ee 47a, 47c, 47h, 92b, 331
note on stratigraphic position of localities in-........-...-.. 159

ivasceralvarea, Gefmed 22s ease =e 296

Wascerall cavity, Gefned =. 2. - ene — = tee oe ee eee 296

Vistula River, Poland, localities on - -.-.- -- 368, 368a, 386e

Volborth, A. von, bibliographic reference.....-..--..---.--------- 24
TOTTI C1 SUL CLO Toe ee 366
species named for..........-.------------ Seca eon scoONS . 419

volborthi, see Obolus.
Volborthia, deseribed....-.-.-------
classification of

evolution discussed.........--.-----5.--.-.----------- 318
evOlUtionOfos sae seen ee eee oe ene eee ee SIF)
false cardinal area mentioned .. 318

general geographic and stratigraphic distribution of
the species referred to..--...--..--.---.-.-.--..---- 99

number of Ordovician species and varieties of......-- 118
number of species of, in different types of sediment.. 160
surface ornamentation discussed. -.-.-....-------------- 301
type species ‘‘Acrotreta recurva” ...-..---------------- 366
TECUNUM.| CESCLIDEO peepee e a eeas aceasta aoe ee eee 366

general geographic and stratigraphic Giehoution
UNO MIG Y Gly Soon eee pea es Sacer seco. sconcenasoce 99
pedicle opening in, discussed and figured ..-.---..--- 366
type specimen figured. ...-..------------- Pl. I, figs. 6, 6a-e
Volkhof (Wolchow) River, St. Petersburg, Russia, localities on.- 336k,
336r, 336x, 337j, 337k, 396k

Vrana, Syveden, locality at....-.-.-- 320V
Waagen, W., bibliographic references. - 24
Wabasha County, Minnesota, localities in 97,

97x, S97x, 99, 131, 339c, 339f, 439h
Wades Gap, Alabama, locality near...-.....-..------------------ 139a
Wahlenberg, G., bibliographic reference. ....-.---------.-------- 24
Wahwah Mountains, Utah, localities in- 34r, 34¢
Wahwah Spring, Utah, localities near_........--..------------- 34r, 34t

INDEX.

Walcott, B. S:; species named for. -.------.------------ <= - 355
Walcott, C. D., bibliographic references. .........---------------- 24,25
Walcott, Mrs. C. D:, species named for........-.-.--------------- 740
Waldheimia, cardinal process discussed....-:...-.-.-------------- 306
Wales, Cambrian species of, listed. .-....-...---.-- 120-121
generalized section of Cambrian and Ordovician in, listing
Species| a0 CM OCHiCS = es eee ee eee 135-136
localities in_-.../.-...-- 805, 305a, 305c-i, 318, 318a—w, 366, 366a-s
Walker’s ranch, Lewis and Clark County, Montana, locality near. 9m
Wallace switch, near Bristol, Tennessee, locality at.....-...------ 22’
Wallerius, I. D:, bibliographic reference...-...-----..----------- 26
Wanner, Atreus, species named for........-.-.--.-------+-------- 613
wanneri, see Yorkia.
wanniecki, see Lingulella.
wapta, see Micromitra (Paterina).
Wapta Peak, British Columbia, locality mnear...........-----.---- 35k

Warth, H., species named for--------.-....-...-..------------- 567, 72
warthi, see Neobolus and Wynnia.
Warwickshire, England, locality in..........-.-.-.---..--.-------
Wasatch Canyon, north of Brigham, Utah, localities in...-...--.- S2p,
: 32x, 33j, 34q, 54k, 54q, 55e, 105x
wasatchensis, see Obolus ( Westonia).
Wasatch Mountains, Utah, see Wasatch Canyon, Calls Fort,
Brigham, Geneva, Blacksmith Fork, Paradise Dry Can-
yon, Patterson, Ogden Canyon, Provo, Big Cottonwood
Canyon, Mona, Weber Canyon, etc.
Washington, see Mount Washington.

Washington County, Maryland, localities in...........-..... 16f, 47d-£
Minnesota, localitiesim= -2 5 2-2-2 .-e-s-- 2-22 ee 339, 339a, 339b
Missouri, localities in---. -- lle, 369b, 369d

iNewexork- localities anes sp) cee eee sen ee cee a 20,

20a, 21, 2la, 22, 22a, 33, 38b, 34, 34a, 35, 35a, 36, 36b, 37, 37b,

38, 38a, 38c, 39, 39a, 43, 48a, 45a, 45b, 109, 110, 110a, 338a,

338c-i, 3881, 338m, 3380, 338p, 338v, 338x, 338z, 367a, 367k, 3671
washingtonensis, see Yorkia.

Waterfall Valley near Maentwrog, North Wales, localitiesin. 3181, 318m

Waucoba Springs, Inyo County, California, localities near. 53, 312, 312a

Waucoba Springs section, 3b (Lower Cambrian), locality in... .-. 3124

WaucobaSpringssection, 3d (Lower Cambrian), localitiesin. 53, 58a?, 312

Waynesboro,’ Pennsylvania, locality near.............-----.----- 49d

Weber Canyon, Morgan County, Utah, locality in-..............- 329¢

Weber County, Utahy localitiesime= 2s. -e----2 sees oe 30p, 30q, 30s

Webs Ridge, Tennessee, locality on........-.-------------------= 12

Weed, W: H:; bibliographic, reference. -_.--..----2-----.--.-..-+ 26

Weeks, F. B., acknowledgments Ber 13

Weeks Canyon, House Range, Utah, localities in........ 30n, 30n’, 300

weeksi see Swantonia.

Weeks limestone (Middle Cambrian), in detailed section in House
Range, Utah, listing included and correlated species and
localities Pee Same s ean ctese ee coe secre Saeeeeseas cee 154-155

NOCAlIt eS ime Ce eee els 2 cece ease cre ats eereese eee 30n, 30n’, 300
TNONbIONC ORS see erase aoe ete soe nae eae ead Se senen e 510
Wehlau, East Prussia, localities near_...........--..-.-.---- 386b, 386i

Weichsel, see Vistula.
‘Weisner quartzite (Lower Cambrian), in generalized section for
Tennessee, Georgia, and Alabama, listing species and locali-

Weller, Stuart, bibliographic reference.
Speciestmamedhorsmeme seco caters eset cs aceete oo ssete ease

welleri, see Linguleila.

Wentlinge, Oeland Island, Sweden, locality at.........-.........

Wermland, Sweden, locality in

Wern, North Wales, locality at

Westergard, A. H., bibliographic reference..................-..-- 26

Westergotland, see Skaraborg, Wermland, etc.

West Gallatin River, Montana, localities on.....................- 4g,
4h, 4k, 4p, 156b, 159, 161, 302, 302h, 302j

Wiesipbrussia; localiiiesimesss=) sess eee eee ee 386d, 3861

AWVEMOML, Ate Coy aly WMCP see seccasceacesoo seeesee leases 451

Westonia, type of surface discussed ........-..----+-..-.-------- 301, 302

(Westonia), see Obolus (Westonia).

Weymouth, see North Weymouth. @)2

Wheeler Amphitheater, House Range, Utah, localities in. -...._. 3s,

: 3t, 3x, 3y, 4, 8g, 11q, 11x, lly, 30g
Wheeler formation (Middle Cambrian), in detailed section in House
Range, Utah, listing included and correlated species and

localities .......... SboBcHoSREESrisoARESEAbeaseconeaseededee 156
localitiestinesesseses see ree sc. - 3s, 3t, 4, 8g, 1lu, 15b
White, C. A., bibliographic references................-.---------- 26

Wihiteayes, J. I-, acknowledgments. -----..22-------------+------ 12
bibliographic reference.....-...-...------ Beodse <a esaanoSe 26
Species named fore ans 2 oe so eee ae eee eaten ees ese 571
AMENUIONEM ae ae Reena eer DESC Sues Ace OBE e ere 335

whiteavesi, see Bicia.
Whitechurch, St. Davids, South Wales, locality near ....----.--- 318q
Whitehall, New York, localities near.... 20a, 34, 39, 45b, 110, 110a, 338m
Whitehall quadrangle, New York, localities in -..-.....-..------ 34,
39, 45b, 110, 110a, 338a, 338m
White Leaved Oak, England, locality at seo > Bi
White Leaved Oak shales (Upper Cambrian), in generalized
section for England, Scotland, and Wales, listing species
and localities ......- sods cdi sdeksece ss sceeceesemeeeecrene 135
localities in 304b, 304e, 304£
White Mountain Range, California, Kutorgina perugata from,

discussed
localities in
White Pine, White Mountain Range, California, locality near. - .- 8b
White Pine County, Nevada, localities in.....................-.. 4l,
Ti, 8e, 8f, 8m—p, 10w, 214a, 214b, 313, 318a, 313b, 313d-f, 313k?
White Pine district, Nevada, localities in.......-...._. 214a, 214b, 313k
Whitesand Bay, near St. Davids, South Wales, locality at.....-- 366

Whitfield, R. P., bibliographic references 26
SHeciesmam CdiOlsee se Eee eee Eeene eee eee ree neeaeee 764

Whitfield, R. P. (Hall, J., and), bibliographic reference 18

whitfieldi, see Billingsella.

Whyte, see Mount Whyte.

wichitaensis, see Hoorthis.

wichitaensis leviusculus, see Hoorthis.

Wiems, Esthonia, Russia, locality at-..............-.------------ 336t

Wieser, Frances, acknowledgments. ............-..--------------- 13
Williams Canyon, Manitou, Colorado, localities in... 186, 186a

Williard, T. E., species named for--.- 358
williardi, see Micromitra (Patcrina).
Willis, Bailey, acknowledgments....-...........--.-------------- 12
Species mame difonsemc ace eer see eesieeseeiee eee eee eee 420
Willis, Bailey, and Blackwelder, Eliot, bibliographic reference. . - - 26
willisi, see Obolus. v
Willow Creek, Gallatin County, Montana, locality on............. 160
Willow River, near Hudson, Wisconsin, locality on.............- 328j
Wiman, Carl, acknowledgments 12
bibliographic reference. - - 26
genus named for 745
species named for = 18
Wamanelladescribed!| 2 yasse-e = se aera ee = ieee oe eenee 745
absence of vascular or muscle markings in, discussed-. 748
Classificatiomtotes sees ace nor noe sce enee eee 321, 325 -
yO ULIOMEGISCUSSEC Bree sees er 320
GMA Oi ge pot ccoseoeaaons aeeseocenoeasousencanses 317
general geographic and stratigraphic Cistribution of

the species referred to... 107
general stratigraphic distribution and number of Cam-

brian species and varieties of...........-- See ae 111
number of species of, in different types of sedi-

MOM Ge eee ee Soe seisle ae ase see Selene eee eee eee 160
reference to, of Wimanella inyoensis discussed. . ae 14h
stratigraphic position mentioned.....-.-...-.- - 320
type species Wimanella simplen.....-.--..----------- 745

#7, ONOTOLA) CeSChIbe desea eee eee a ee eee eee 745
. compared with Billingsella appalachia. 750
Wimanella shelbyensis.........-.-.------------- 748

general geographic and stratigraphic distribution tab-

DIY rlo Were oecuiqee cacsedesooqsoakeseassbesuanase eer 107
type specimen figured .-.......----..- Pl. LXXXVII, fig. 1

RaTULensis WOeSChiDe Cae ease nee n eee sees eee ee - 746
compared with Billingsella coloradoensis 745
‘Billingsellayplicatellees== sees eee -- 745
Wimanellasajfordt=eenseesee eee cease eae TAT

general geographic and stratigraphic distribution tab-

lated eeewe seer tes Cease Peer ae oe cee 107
type specimen figured....-.....-.-- Pl. LX X XVII, fig. 5b

PGS, CEH eel. a5 - <\ soonsesosoodsseaaecescaessaoecs 746
general geographic and stratigraphic distribution tab-

Wale le eocibo Ome poncuobocsancecHEeabe ren Ssnaemaeoae 107
type specimen figured --- ... text fig. 683A, 747

SayfOTd? CeSCHIDE Clee ee eee eae eee eee 747
general geographic and stratigraphic distribution tab-

Bee eee nee cia seme ee eas eee sas Eee 107

Pl. LXXXVII, fig. 7

872

Wimanella shelbyensis, described .---..----------------------+---- 747
general geographic and stratigraphic distribution tab-

WENA se seesascnosSescccracccnsoasoasescesecsossy 107

type specimen figured...-....---.-.----------- Pl. Il, fig. 9

simplex, described ...------------------------- Weeteece 748

compared with Wimanella shelbyensis 748
general geographic and stratigraphic distribution fsb

DIP elle eee seesaemn coos aoa seems obese sso sdoee eens 107

type of Wimanella g SoM)

type specimen figured ---...----------
wimani, see Eoorthis and Obolus ( Westonia).

Winchell, A., bibliographic reference..-..----.-------------------- 26
Winchell, N. H., bibliographic reference --....-------------------- 26
Winchell, N. H., and Schuchert, C., bibliographic reference... .-- 26

Windjuelandet, Rosy ay, localities at-----------.-----
Winfield, Wisconsin, localities at and near
winfieldensis, see Eoorthis remnicha.

Wing, Augustus, species named for... .-------------------------- _ 743
wingi, see Protorthis.
Winona, Minnesota, localities near. .----.------------------- 339g, 339k

winona, see Lingulella.
winona convera, see Lingulella.

Winona County, Minnesota, localities in-... 84, 84f, 84s, 99, 339f-h, 339k

Wirrialpa, South Australia, localities at..-..------------------- 315b-d
wirrialpensis, see Obolelia.

wirthi, see Lingulella.

Wisconsin, Cambrian species of, listed -...---- SS SESE Oe onsen 114-119

localitiesin.. 10v, 78, 78a-d, 78s, 79, 79’, 79a, 79b, 79s, 79x, 80, 80a, 81,
81b, 810, 82, 82a, 82s, 83, 83’, 85, 85a, 85s, 85x, S85x, 852,
86, 86a, 97a, 97c, 98, 98x, 99a, 100, 100a, 116, 134, 134a,
135, 135b, 135¢, 328, 328a-n, 328p, 328q, 364, 364a

note on stratigraphic position of localities in----...--------- 159

Wismar, Germany, locality near -.---.------------------+-------- 386f
Wolchow, see Volkhof. “
Woleschna, Bohemia, locality near.-..--..----------------------- 303h
Wolf Creek, Bighorn Mountains, Wyoming, locality on----.------ 14k
Wolf Creek, Virginia, locality on--..-...------------------------- 47h
Wolsey, Montana, localities near -.--..--.-------------------- 5f, 5k, 340
Wolsey shale (Middle Cambrian), localities in--..-------- 4x, 5f

note on stratigraphic position and correlation of. --. 137

Wood, Elvira, acknowledgments-.-...-...------------------------ 13
Wood Cone, Eureka district, Nevada, localities on-.....-
Woodstock, Alabama, locality mear........-----------------------
Woodworth, J. B., species named for..........-------------------
woodworthi, see Acrothele.

Worcestershire, England, localities in...---.-.--------
Wormditt, East Prussia, locality near.-..-..---.--.---.----------- 386k
Worthen, A. H., species.named for. .-.-...------------------------ 421
wortheni, see Obolus.

90b

Wraz, Bohemia, locality at... 303n
Wutaihien, China, locality near C75
Wynantskill, New York, localities near .---..---------------- 72a, 33&k
Wynne, Arthur B., genus named for.......---------------------- 771
Wynnia, described. ..--.----------------------- oy eel
cardinal area discussed -....-------------------------- 305
GESSTED NOS Oise coos Soon oeseessbozesedseSssceeses 321,325
evolution of 317
general geographic and stratigraphic distribution of
the species referred to.......----------------------- 108
general stratigraphic distribution and number of Cam-
brian species and varieties of. ...-..----.----------- 111
number of species of, in different types of sediment... 160
stratigraphic position mentioned 320
warthi, described 771
general geographic and stratigraphic distribution
UD QWIR AEG! S 5 oe spent ceotee soo soscooS=sosseessccocre8 108
type specimen figured. -.......- --P]. LXXXIX, fig. 4a
Wyoming, Cambrian species of, listed.....-..--.--.------------- 114-119
. localities in (Middle Cambrian) -....-.-.-.--------- 4e, 4j, 4m-o,

170, 171, 171a, 302b, 3021, 302m, 3020, 302x, 302y, 340c, 340d
localities in (Upper Cambrian) ....-...-.---.--------------- 14k,
168, 302c-e, 302g-h, 302p, 302u

note on stratigraphic position of localities in...-.-.----.---- 144
stratigraphic position of localities in, discussed

CAMBRIAN BRACHIOPODA.

Wysog6rski, Johann, bibliographic reference... - - SEES Sesiasace bn 26
Yanceys Bend, Coosa River, Alabama, locality at -- 92x
Yellowstone National Park, Wyoming, localities in 4j,

302b, 302c, 3028-1 h, 3021

Yellowstone River, Montana, locality east of
Yenchaung, China, localities at and near_......-.....------------

C9, C10, lz, C61, C62, C63, C64

Yogo limestone (Upper Cambrian), localities in“ 302q, 302r

note on stratigraphic position of 137

York, Pennsylvania, localities at and near. 8q, 48d, 49a, 49e, 50, 50a, 346c

York County, Pennsylvania, localities in..-- 8q,

48d, 49, 49a—c, 49e, 49w, 50, 50a, 346, 346c

yorkensis, see Acrothele.

Yorke Peninsula, South Australia, localities on 315, 315a

Yorkia, described a 611
cardinal area discussed=--222------2--------------~--= 305
Classification! ofeesssess- eee ees ee ee eters 321, 324
compared with Quebecia. Hs OLE
Cra bhinoya CbIURECLS = ooo gemciggsegs2scee=ssezencoscu 319
evolution of 317
general geographic and stratigraphic distribution of

the species referred to......-.-.--.----------------- 104
general stratigraphic distribution and number of Cam-

brian species and varieties of........-.------------- 111
muscle scars not shown in........-.--..-------------- 313
number of species of, in different types of sediment... 160
reference to, of Yorkia ? miqueli discussed... .---.-.- 612
reference to, of Yorkia ? orientalis discussed 612

reference to, of Yorkia ? washingtonensis discussed... 612,613

Sai Solo sieWe GOs =< 2o2 coos cence eeeeseccsecas seoneeness 297

stratigraphic position mentioned - 318

type species Yorkia wanneri.-.-...-.----------------- 611

vascular markings discussed. -_......--.-------------- 311

RAIA REL) CLES CC ee eee ta eee eee eee 611
general geographic and stratigraphic distribution tabu-

late dis. cusues.Saecee teens ee eecae: eee eaere eres 104

type specimen figured. -.....-.--------- Pl. LXXXII, fig. 4 ~

PLOTLENLOUS A OCSCULDE Cee eee ee ee eet 612
general geographic and stratigraphic distribution tabu-

lated )<=>. cesses eee eee ao eee er eee 104

type specimen figured ......------------ Pl. LXXNIL, fig. 3

wanmneri, described 612

compared with Yorkia ? orientalis 612
general geographic and stratigraphic distribution tabu-

IPN ae soe sotisnoccessectesccenccnoc suc bonsuscesess 104

TRAD O MON hoe sos acbeos=ossoostensaasaensess2ooccs 611

type specimen figured Pl. LXXXIL, fig. 1g

« ? washingtonensis, described- 613
general geographic and stratigraphic distrbution tabu-

TEKICU hoe ah ek RE AS Saas Reoeansasorce beiosocwee 104

generic reference discussed 612

type specimen figured...--..-..---..---- Pl. LX XXII, fig. 2

Youngs Creek, Ovando quadrangle, Montana, localities near... -- 4q,

Youngs (McPhees) Point, Nova Scotia, locality on...

Ytterniiset, Aland Island, Finland, localities at 31l1q, 3lly
Zarskoe Selo, St. Petersburg, Russia, localities at.-.....----- 336g, 3962
Zbirov, see Shirov.

zeno, see Hoorthis.

zenobia, see Micromitra.

zetus, see Obolus.

zeus, see Lingulella. ;
Ziegelskoppel, Esthonia, Russia, locality at-.--....-------------- 396¢
Zittel, K. A. von, bibliographic reference ....---.------------------- 26
Zone BIlla or BIIIf (Ordovician), locality in.--.-.-------------- 337j
Zone C of Westergard (Passage beds), locality in-.--.-.-.--------- 310W

Zone 1 of Moberg and Segerberg (Upper Cambrian), locaiity in---
Zone 2 of Moberg and Segerberg (Upper Cambrian), locality in... 309a
Zone 3 of Moberg and Segerberg (Up pper Cambrian), localities
ATT oe oe crethe Se eeie see ae Osea eee ei eater toa 390b, 390e
See also Shumardia zone and Ceratopyge slate.
Zone 4 of Moberg and Segerberg (Passage beds), localities in... 309, 310
See also Ceratopyge limestone.
Zoological discussion... .-.-----------------+---++-++2222522 27-7
zoppi, see Obolus.

ai